1
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Uhlmann C, Feuerstein TJ, Gamer MT, Roesky PW. Coinage Metal Bis(amidinate) Complexes as Building Blocks for Self-Assembled One-Dimensional Coordination Polymers. Chemistry 2023; 29:e202300289. [PMID: 36762591 DOI: 10.1002/chem.202300289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/09/2023] [Accepted: 02/09/2023] [Indexed: 02/11/2023]
Abstract
The pyridyl functionalized amidinate [{PyC≡CC(NDipp)2 }Li(thf)2 ]n was used to synthesize a series of bis-amidinate complexes [{PyC≡CC(NDipp)2 }2 M2 ] (M=Cu, Ag, Au) with fully supported metallophilic interactions. These metalloligands were then used as building blocks for the synthesis of one-dimensional heterobimetallic coordination polymers using Zn(hfac)2 (hfac=hexaflouroacetylacetonate) for self-assembly. Interestingly, the three coordination polymers [{PyC≡CC(NDipp)2 }2 M2 ][Zn(hfac)2 ] (M=Cu, Ag, Au), exhibit a zig zag shape in the solid state. To achieve linear coordination geometry other connectors such as M'(acac) (M'=Ni, Co) (acac=acetylacetonate) were investigated. The thus obtained compounds [{PyC≡CC(NDipp)2 }2 Cu2 ][M'(acac)2 ] (M'=Ni, Co) are indeed linear heterobimetallic coordination polymers featuring a metalloligand backbone with fully supported metallophilic interactions.
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Affiliation(s)
- Cedric Uhlmann
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Thomas J Feuerstein
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Michael T Gamer
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Peter W Roesky
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
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2
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Uhlmann C, Feuerstein TJ, Seifert TP, Jung AP, Gamer MT, Köppe R, Lebedkin S, Kappes MM, Roesky PW. Luminescent early-late-hetero-tetranuclear group IV - Au(I) bisamidinate complexes. Dalton Trans 2022; 51:10357-10360. [PMID: 35776128 DOI: 10.1039/d2dt00458e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The versatile metalloligand [{HCCC(NDipp)2}2Au2] (dipp = 2,6-diisopropylphenyl) was converted into early-late heterotetrametallic complexes [{ClCp2MCCC(NDipp)2}2Au2] (M = Ti, Zr). These compounds show photoluminescence with either remarkably different (Ti) or similar (Zr) features as compared to related solely coinage metal containing acetylide amidinate complexes.
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Affiliation(s)
- Cedric Uhlmann
- Institute for Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
| | - Thomas J Feuerstein
- Institute for Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
| | - Tim P Seifert
- Institute for Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
| | - André P Jung
- Institute for Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
| | - Michael T Gamer
- Institute for Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
| | - Ralf Köppe
- Institute for Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
| | - Sergei Lebedkin
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Manfred M Kappes
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.,Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany
| | - Peter W Roesky
- Institute for Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
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Goswami B, Feuerstein TJ, Yadav R, Lebedkin S, Boden PJ, Steiger ST, Niedner‐Schatteburg G, Gerhards M, Kappes MM, Roesky PW. Cover Feature: Thermally Activated Delayed Fluorescence and Phosphorescence Quenching in Iminophosphonamide Copper and Zinc Complexes (Chem. Eur. J. 61/2021). Chemistry 2021. [DOI: 10.1002/chem.202102063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Bhupendra Goswami
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology (KIT) Engesserstrasse 15 76131 Karlsruhe Germany
| | - Thomas J. Feuerstein
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology (KIT) Engesserstrasse 15 76131 Karlsruhe Germany
| | - Ravi Yadav
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology (KIT) Engesserstrasse 15 76131 Karlsruhe Germany
| | - Sergei Lebedkin
- Institute of Nanotechnology Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Pit J. Boden
- Fachbereich Chemie und Forschungszentrum OPTIMAS TU Kaiserslautern 67663 Kaiserslautern Germany
| | - Sophie T. Steiger
- Fachbereich Chemie und Forschungszentrum OPTIMAS TU Kaiserslautern 67663 Kaiserslautern Germany
| | | | - Markus Gerhards
- Fachbereich Chemie und Forschungszentrum OPTIMAS TU Kaiserslautern 67663 Kaiserslautern Germany
| | - Manfred M. Kappes
- Institute of Nanotechnology Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
- Institute of Physical Chemistry Karlsruhe Institute of Technology (KIT) Fritz-Haber Weg 2 76131 Karlsruhe Germany
| | - Peter W. Roesky
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology (KIT) Engesserstrasse 15 76131 Karlsruhe Germany
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Goswami B, Feuerstein TJ, Yadav R, Lebedkin S, Boden PJ, Steiger ST, Niedner‐Schatteburg G, Gerhards M, Kappes MM, Roesky PW. Thermally Activated Delayed Fluorescence and Phosphorescence Quenching in Iminophosphonamide Copper and Zinc Complexes. Chemistry 2021; 27:15109-15118. [PMID: 33899967 PMCID: PMC8596734 DOI: 10.1002/chem.202101247] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Indexed: 11/17/2022]
Abstract
The synthesis of copper and zinc complexes of four variably substituted iminophosphonamide ligands is presented. While the copper complexes form ligand-bridged dimers, the zinc compounds are monomeric. Due to different steric demand of the ligand the arrangement of the ligands within the dimeric complexes varies. Similar to the structurally related iminophosphonamide complexes of alkali metals and calcium, the steady-state and time-resolved photoluminescence (PL) of four of the seven compounds studied here as solids in a temperature range of 5-295 K can be described within the scheme of thermally activated delayed fluorescence (TADF). Accordingly, they exhibit bright blue-green phosphorescence at low temperatures (<100 K), which turns into delayed fluorescence by increasing the temperature. However, unusually, the fluorescence is practically absent in two copper complexes which otherwise still conform to the TADF scheme. In these cases, the excited singlet states decay essentially non-radiatively and their thermal population from the corresponding low-lying triplet states efficiently quenches PL (phosphorescence). Three other copper and zinc complexes only exhibit prompt fluorescence, evidencing a wide variation of photophysical properties in this class of compounds. The excited states of the copper complex with especially pronounced phosphorescence quenching were also investigated by low-temperature time-resolved infrared spectroscopy and quantum chemical calculations.
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Affiliation(s)
- Bhupendra Goswami
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstrasse 1576131KarlsruheGermany
| | - Thomas J. Feuerstein
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstrasse 1576131KarlsruheGermany
| | - Ravi Yadav
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstrasse 1576131KarlsruheGermany
| | - Sergei Lebedkin
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT)Hermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
| | - Pit J. Boden
- Fachbereich Chemie und Forschungszentrum OPTIMASTU Kaiserslautern67663KaiserslauternGermany
| | - Sophie T. Steiger
- Fachbereich Chemie und Forschungszentrum OPTIMASTU Kaiserslautern67663KaiserslauternGermany
| | | | - Markus Gerhards
- Fachbereich Chemie und Forschungszentrum OPTIMASTU Kaiserslautern67663KaiserslauternGermany
| | - Manfred M. Kappes
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT)Hermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT)Fritz-Haber Weg 276131KarlsruheGermany
| | - Peter W. Roesky
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstrasse 1576131KarlsruheGermany
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Zovko C, Schoo C, Feuerstein TJ, Münzfeld L, Knöfel ND, Lebedkin S, Kappes MM, Roesky PW. Alkali Metal Complexes of a Bis(diphenylphosphino)methane Functionalized Amidinate Ligand: Synthesis and Luminescence. Chemistry 2021; 27:15119-15126. [PMID: 34427374 PMCID: PMC8596514 DOI: 10.1002/chem.202102243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Indexed: 12/22/2022]
Abstract
A novel bis(diphenylphosphino)methane (DPPM) functionalized amidine ligand (DPPM-C(N-Dipp)2 H) (Dipp=2,6-diisopropylphenyl) was synthesized. Subsequent deprotonation with suitable alkali metal bases resulted in the corresponding complexes [M{DPPM-C(N-Dipp)2 }(Ln )] (M=Li, Na, K, Rb, Cs; L=thf, Et2 O). The alkali metal complexes form monomeric species in the solid state, exhibiting intramolecular metal-π-interactions. In addition, a caesium derivative [Cs{PPh2 CH2 -C(N-Dipp)2 }]6 was obtained by cleavage of a diphenylphosphino moiety, forming an unusual six-membered ring structure in the solid state. All complexes were fully characterized by single crystal X-ray diffraction, NMR spectroscopy, IR spectroscopy as well as elemental analysis. Furthermore, the photoluminescent properties of the complexes were thoroughly investigated, revealing differences in emission with regards to the respective alkali metal. Interestingly, the hexanuclear [Cs{PPh2 CH2 -C(N-Dipp)2 }]6 metallocycle exhibits a blue emission in the solid state, which is significantly red-shifted at low temperatures. The bifunctional design of the ligand, featuring orthogonal donor atoms (N vs. P) and a high steric demand, is highly promising for the construction of advanced metal and main group complexes.
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Affiliation(s)
- Christina Zovko
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstraße 1576131KarlsruheGermany
| | - Christoph Schoo
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstraße 1576131KarlsruheGermany
| | - Thomas J. Feuerstein
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstraße 1576131KarlsruheGermany
| | - Luca Münzfeld
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstraße 1576131KarlsruheGermany
| | - Nicolai D. Knöfel
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstraße 1576131KarlsruheGermany
| | - Sergei Lebedkin
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT)Hermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
| | - Manfred M. Kappes
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT)Hermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT)Fritz-Haber-Weg. 276131KarlsruheGermany
| | - Peter W. Roesky
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstraße 1576131KarlsruheGermany
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Feuerstein TJ, Schlicker E. β 1-Blockers Enhance Inotropy of Endogenous Catecholamines in Chronic Heart Failure. Front Cardiovasc Med 2021; 8:639562. [PMID: 34179127 PMCID: PMC8220816 DOI: 10.3389/fcvm.2021.639562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 04/19/2021] [Indexed: 11/30/2022] Open
Abstract
Although β1-blockers impressively reduce mortality in chronic heart failure (CHF), there are concerns about negative inotropic effects and worsening of hemodynamics in acute decompensated heart failure. May receptor theory dispel these concerns and confirm clinical practice to use β1-blockers? In CHF, concentrations of catecholamines at the β1-adrenoceptors usually exceed their dissociation constants (KDs). The homodimeric β1-adrenoceptors have a receptor reserve and display negative cooperativity. We considered the binomial distribution of occupied receptor dimers with respect to the interaction of an exogenous β1-blocker and elevated endogenous agonist concentrations > [KDs], corresponding to an elevated sympathetic tone. Modeling based on binomial distribution suggests that despite the presence of a low concentration of the antagonist, the activation of the dimer receptors is higher than that in its absence. Obviously, the antagonist improves the ratio of the dimer receptors with only single agonist activation compared with the dimer receptors with double activation. This leads to increased positive inotropic effects of endogenous catecholamines due to a β1-blocker. To understand the positive inotropic sequels of β1-blockers in CHF is clinically relevant. This article may help to eliminate the skepticism of clinicians about the use of β1-blockers because of their supposed negative inotropic effect, since, on the contrary, a positive inotropic effect can be expected for receptor-theoretical reasons.
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Affiliation(s)
- Thomas J Feuerstein
- Sektion für Neuroelektronische Systeme, Klinik für Neurochirurgie, Universität Freiburg, Breisgau, Germany.,Freiburg Institute for Advanced Studies, Albert-Ludwigs-Universität Freiburgf and Institut für Pharmakologie und Toxikologie, Universität Bonn, Bonn, Germany
| | - Eberhard Schlicker
- Institut für Pharmakologie und Toxikologie, Universität Bonn, Bonn, Germany
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Goswami B, Feuerstein TJ, Yadav R, Köppe R, Lebedkin S, Kappes MM, Roesky PW. Enantiopure Calcium Iminophosphonamide Complexes: Synthesis, Photoluminescence, and Catalysis. Chemistry 2021; 27:4401-4411. [PMID: 33355402 PMCID: PMC7986735 DOI: 10.1002/chem.202004833] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/21/2020] [Indexed: 11/09/2022]
Abstract
The synthesis of calcium complexes ligated by three different chiral iminophosphonamide ligands, L-H (L=[Ph2 P{N(R)CH(CH3 )Ph}2 ]), L'-H (L'=[Ph2 P{NDipp}{N(R)CH(CH3 )Ph}]), (Dipp=2,6-i Pr2 C6 H3 ), and L''-H (L''=[Ph2 P{N(R)CH(CH3 )naph}2 ]), (naph=naphthyl) is presented. The resulting structures [L2 Ca], [L'2 Ca], and [L''2 Ca] represent the first examples of enantiopure homoleptic calcium complexes based on this type of ligands. The calcium complexes show blue-green photoluminescence (PL) in the solid state, which is especially bright at low temperatures. Whereas the emission of [L''2 Ca] is assigned to the fluorescence of naphthyl groups, the PL of [L2 Ca] and [L'2 Ca] is contributed by long-lived phosphorescence and thermally activated delayed fluorescence (TADF), with a strong variation of the PL lifetimes over the temperature range of 5-295 K. Furthermore, an excellent catalytic activity was found for these complexes in hydroboration of ketones at room temperature, although no enantioselectivity was achieved.
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Affiliation(s)
- Bhupendra Goswami
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
| | - Thomas J Feuerstein
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
| | - Ravi Yadav
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
| | - Ralf Köppe
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
| | - Sergei Lebedkin
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Manfred M Kappes
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.,Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber Weg 2, 76131, Karlsruhe, Germany
| | - Peter W Roesky
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
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Feuerstein TJ, Seifert TP, Jung AP, Müller R, Lebedkin S, Kappes MM, Roesky PW. Efficient Blue Phosphorescence in Gold(I)-Acetylide Functionalized Coinage Metal Bis(amidinate) Complexes. Chemistry 2020; 26:16676-16682. [PMID: 32520425 PMCID: PMC7756867 DOI: 10.1002/chem.202002466] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Indexed: 01/27/2023]
Abstract
The synthesis of linear symmetric ethynyl- and acetylide-amidinates of the coinage metals is presented. Starting with the desilylation of the complexes [{Me3 SiC≡CC(NDipp)2 }2 M2 ] (Dipp=2,6-diisopropylphenyl) (M=Cu, Au) it is demonstrated that this compound class is suitable to serve as a versatile metalloligand. Deprotonation with n-butyllithium and subsequent salt metathesis reactions yield symmetric tetranuclear gold(I) acetylide complexes of the form [{(PPh3 )AuC≡CC(NDipp)2 }2 M2 ] (M=Cu, Au). The corresponding Ag complex [{(PPh3 )AuC≡CC(NDipp)2 }2 Ag2 ] was obtained by a different route via metal rearrangement. All compounds show bright blue or blue-green microsecond long phosphorescence in the solid state, hence their photophysical properties were thoroughly investigated in a temperature range of 20-295 K. Emission quantum yields of up to 41 % at room temperature were determined. Furthermore, similar emissions with quantum yields of 15 % were observed for the two most brightly luminescent complexes in thf solution.
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Affiliation(s)
- Thomas J. Feuerstein
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstrasse 1576131KarlsruheGermany
| | - Tim P. Seifert
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstrasse 1576131KarlsruheGermany
| | - André P. Jung
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstrasse 1576131KarlsruheGermany
| | - Rouven Müller
- Macromolecular ArchitecturesInstitute for Chemical Technology and Polymer Chemistry (ITCP)Karlsruhe Institute of Technology (KIT)Engesserstrasse 1876131KarlsruheGermany
| | - Sergei Lebedkin
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT)Hermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
| | - Manfred M. Kappes
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT)Hermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT)Fritz-Haber Weg 276131KarlsruheGermany
| | - Peter W. Roesky
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT)Engesserstrasse 1576131KarlsruheGermany
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Feuerstein TJ, Seifert TP, Jung AP, Müller R, Lebedkin S, Kappes MM, Roesky PW. Cover Feature: Efficient Blue Phosphorescence in Gold(I)‐Acetylide Functionalized Coinage Metal Bis(amidinate) Complexes (Chem. Eur. J. 70/2020). Chemistry 2020. [DOI: 10.1002/chem.202003341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Thomas J. Feuerstein
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology (KIT) Engesserstrasse 15 76131 Karlsruhe Germany
| | - Tim P. Seifert
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology (KIT) Engesserstrasse 15 76131 Karlsruhe Germany
| | - André P. Jung
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology (KIT) Engesserstrasse 15 76131 Karlsruhe Germany
| | - Rouven Müller
- Macromolecular Architectures Institute for Chemical Technology and Polymer Chemistry (ITCP) Karlsruhe Institute of Technology (KIT) Engesserstrasse 18 76131 Karlsruhe Germany
| | - Sergei Lebedkin
- Institute of Nanotechnology Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Manfred M. Kappes
- Institute of Nanotechnology Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
- Institute of Physical Chemistry Karlsruhe Institute of Technology (KIT) Fritz-Haber Weg 2 76131 Karlsruhe Germany
| | - Peter W. Roesky
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology (KIT) Engesserstrasse 15 76131 Karlsruhe Germany
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Seifert TP, Naina VR, Feuerstein TJ, Knöfel ND, Roesky PW. Molecular gold strings: aurophilicity, luminescence and structure-property correlations. Nanoscale 2020; 12:20065-20088. [PMID: 33001101 DOI: 10.1039/d0nr04748a] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This review covers the compound class of one-dimensional gold strings. These compounds feature a formally infinite repetition of gold complexes as monomers/repeating units that are held together by aurophilic interactions, i.e. direct gold-gold contacts. Their molecular structures are primarily determined in the solid state using single crystal X-ray diffraction. The chemical composition of the employed gold complexes is diverse and furthermore plays a key role in terms of structure characteristics and the resulting properties. One of the most common features of gold strings is their photoluminescence upon UV excitation. The emission energy is often dependent on the distance of adjacent gold ions and the electronic structure of the whole string. In terms of gold strings, these parameters can be fine-tuned by external stimuli such as solvent, pH value, pressure or mechanical stress. This leads to direct structure-property correlations, not only with regard to the photophysical properties, but also electric conductivity for potential application in nanoelectronics. Concerning these correlations, gold strings, consisting of self-assembled individual complexes as building blocks, are the ideal compound class to look at, as perturbations by an inhomogeneity in the ligand sphere (such as the end of a molecule) can be neglected. Therefore, the aim of this review is to shed light on the past achievements and current developments in this area.
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Affiliation(s)
- Tim P Seifert
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
| | - Vanitha R Naina
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
| | - Thomas J Feuerstein
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
| | - Nicolai D Knöfel
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
| | - Peter W Roesky
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany.
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11
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Altenmüller D, Hebel JM, Deniz C, Volz S, Zentner J, Feuerstein TJ, Moser A. Electrocorticographic and neurochemical findings after local cortical valproate application in patients with pharmacoresistant focal epilepsy. Epilepsia 2020; 61:e60-e65. [DOI: 10.1111/epi.16523] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 04/07/2020] [Accepted: 04/10/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Dirk‐Matthias Altenmüller
- Epilepsy Center Department of Neurosurgery Medical Center – University of FreiburgFaculty of Medicine, University of Freiburg Freiburg Germany
| | - Jonas M. Hebel
- Department of Neurology Charité – Universitätsmedizin Berlin Berlin Germany
| | - Cagan Deniz
- Department of Neurology and Center of Brain, Behavior and Metabolism University of Lübeck Lübeck Germany
- Faculty of Medicine Marmara University Istanbul Turkey
| | - Silvanie Volz
- Clinic for Plastic, Reconstructive und Aesthetic Surgery Klinikum Westfalen Dortmund Germany
| | - Josef Zentner
- Department of Neurosurgery Medical Center – University of FreiburgFaculty of Medicine, University of Freiburg Freiburg Germany
| | - Thomas J. Feuerstein
- Section of Neuroelectronic Systems Department of Neurosurgery Medical Center – University of FreiburgFaculty of Medicine, University of Freiburg Freiburg Germany
| | - Andreas Moser
- Department of Neurology and Center of Brain, Behavior and Metabolism University of Lübeck Lübeck Germany
- Freiburg Institute for Advanced Studies University of Freiburg Freiburg Germany
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Feuerstein TJ, Müller R, Barner-Kowollik C, Roesky PW. Investigating the Photochemistry of Spiropyran Metal Complexes with Online LED-NMR. Inorg Chem 2019; 58:15479-15486. [DOI: 10.1021/acs.inorgchem.9b02547] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Thomas J. Feuerstein
- Institute of Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131 Karlsruhe, Germany
| | - Rouven Müller
- Macromolecular Architectures, Institute for Chemical Technology and Polymer Chemistry (ITCP), Karlsruhe Institute of Technology (KIT), Engesserstrasse 18, 76128 Karlsruhe, Germany
| | - Christopher Barner-Kowollik
- Macromolecular Architectures, Institute for Chemical Technology and Polymer Chemistry (ITCP), Karlsruhe Institute of Technology (KIT), Engesserstrasse 18, 76128 Karlsruhe, Germany
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, Queensland 4000, Australia
| | - Peter W. Roesky
- Institute of Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131 Karlsruhe, Germany
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Simler T, Möbius K, Müller K, Feuerstein TJ, Gamer MT, Lebedkin S, Kappes MM, Roesky PW. Mono- and Dinuclear Coinage Metal Complexes Supported by an Imino-Pyridine-NHC Ligand: Structural and Photophysical Studies. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00449] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas Simler
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany
| | - Karen Möbius
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany
| | - Kerstin Müller
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany
| | - Thomas J. Feuerstein
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany
| | - Michael T. Gamer
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany
| | - Sergei Lebedkin
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Manfred M. Kappes
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
- Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany
| | - Peter W. Roesky
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany
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Feuerstein TJ, Goswami B, Rauthe P, Köppe R, Lebedkin S, Kappes MM, Roesky PW. Alkali metal complexes of an enantiopure iminophosphonamide ligand with bright delayed fluorescence. Chem Sci 2019; 10:4742-4749. [PMID: 31160950 PMCID: PMC6510313 DOI: 10.1039/c9sc00629j] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 03/11/2019] [Indexed: 12/22/2022] Open
Abstract
Alkali metal complexes of an enantiopure iminophosphonamide bearing chiral centers at both nitrogen atoms are described. They show bright phosphorescence and thermally activated delayed fluorescence (TADF).
The enantiomerically pure ligand P,P-diphenyl-N,N′-bis((R)-1-phenylethyl)phosphinimidic amide (1; (R)-HPEPIA) was synthesized and subsequently deprotonated with alkali metal precursors to yield dimeric complexes [M2{(R)-PEPIA}2] (M = Li (2), Na (3), K (4), Rb (5)). The cesium compound [M{(R)-PEPIA}] (6) crystallized as a cocrystal composed of dimeric ([Cs2{(R)-PEPIA}2] (6d) and 1D-polymeric ([Cs{(R)-PEPIA}]n) (6p) species in a 1 : 1 ratio. The coordination polymer 6p features a unique sinus-shaped configuration of repeating –Cs–N–P–N–Cs–N–P–N– units. Unusual photoluminescence (PL) properties were found for solid 1–6: in contrast to the fluorescent ligand 1, the alkali metal complexes show phosphorescence at low temperatures (<100 K) and thermally activated delayed fluorescence (TADF) above ∼150 K. The latter provides for PL quantum yields up to 36% (3) at ambient temperature. DFT calculations support that both 1 and 2–6d have similar singlet and triplet excited states with energy separations of a few tens of meV. The strongly enhanced intersystem crossing (ISC) in the metal complexes, resulting in TADF, is attributed to their dimeric structure. This suggests that the fluorophore dimerization may serve as a tool to effect ISC for the design of TADF emitters.
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Affiliation(s)
- Thomas J Feuerstein
- Institute for Inorganic Chemistry , Karlsruhe Institute of Technology (KIT) , Engesserstr. 15 , 76131 Karlsruhe , Germany .
| | - Bhupendra Goswami
- Institute for Inorganic Chemistry , Karlsruhe Institute of Technology (KIT) , Engesserstr. 15 , 76131 Karlsruhe , Germany .
| | - Pascal Rauthe
- Institute for Inorganic Chemistry , Karlsruhe Institute of Technology (KIT) , Engesserstr. 15 , 76131 Karlsruhe , Germany .
| | - Ralf Köppe
- Institute for Inorganic Chemistry , Karlsruhe Institute of Technology (KIT) , Engesserstr. 15 , 76131 Karlsruhe , Germany .
| | - Sergei Lebedkin
- Institute of Nanotechnology , Karlsruhe Institute of Technology (KIT) , Hermann-von-Helmholtz-Platz 1 , 76344 , Eggenstein-Leopoldshafen , Germany
| | - Manfred M Kappes
- Institute of Nanotechnology , Karlsruhe Institute of Technology (KIT) , Hermann-von-Helmholtz-Platz 1 , 76344 , Eggenstein-Leopoldshafen , Germany.,Institute of Physical Chemistry , Karlsruhe Institute of Technology (KIT) , Fritz-Haber-Weg. 2 , 76131 Karlsruhe , Germany
| | - Peter W Roesky
- Institute for Inorganic Chemistry , Karlsruhe Institute of Technology (KIT) , Engesserstr. 15 , 76131 Karlsruhe , Germany .
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Seifert TP, Knoefel ND, Feuerstein TJ, Reiter K, Lebedkin S, Gamer MT, Boukis AC, Weigend F, Kappes MM, Roesky PW. Frontispiece: Size Matters: From Two‐Dimensional Au
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–Tl
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Metallopolymers to Molecular Complexes by Simple Variation of the Steric Demand. Chemistry 2019. [DOI: 10.1002/chem.201981565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Tim P. Seifert
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
| | - Nicolai D. Knoefel
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
| | - Thomas J. Feuerstein
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
| | - Kevin Reiter
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT) Fritz-Haber-Weg 2 76131 Karlsruhe Germany
| | - Sergei Lebedkin
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT) Herrmann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Michael T. Gamer
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
| | - Andreas C. Boukis
- Institute of Organic ChemistryKarlsruhe Institute of Technology (KIT) Fritz-Haber-Weg 6 76131 Karlsruhe Germany
| | - Florian Weigend
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT) Herrmann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Manfred M. Kappes
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT) Fritz-Haber-Weg 2 76131 Karlsruhe Germany
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT) Herrmann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Peter W. Roesky
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
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Seifert TP, Klein J, Gamer MT, Knöfel ND, Feuerstein TJ, Sarkar B, Roesky PW. Synthesis, Spectroscopy, and Redox Studies of Ferrocene-Functionalized Coinage Metal Alkyne Complexes. Inorg Chem 2019; 58:2997-3006. [DOI: 10.1021/acs.inorgchem.8b02873] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tim P. Seifert
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstraße 15, D-76131 Karlsruhe, Germany
| | - Johannes Klein
- Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34−36, D-14195 Berlin, Germany
| | - Michael T. Gamer
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstraße 15, D-76131 Karlsruhe, Germany
| | - Nicolai D. Knöfel
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstraße 15, D-76131 Karlsruhe, Germany
| | - Thomas J. Feuerstein
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstraße 15, D-76131 Karlsruhe, Germany
| | - Biprajit Sarkar
- Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34−36, D-14195 Berlin, Germany
| | - Peter W. Roesky
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstraße 15, D-76131 Karlsruhe, Germany
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Seifert TP, Knoefel ND, Feuerstein TJ, Reiter K, Lebedkin S, Gamer MT, Boukis AC, Weigend F, Kappes MM, Roesky PW. Size Matters: From Two‐Dimensional Au
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–Tl
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Metallopolymers to Molecular Complexes by Simple Variation of the Steric Demand. Chemistry 2019; 25:3799-3808. [DOI: 10.1002/chem.201805984] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Indexed: 11/12/2022]
Affiliation(s)
- Tim P. Seifert
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
| | - Nicolai D. Knoefel
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
| | - Thomas J. Feuerstein
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
| | - Kevin Reiter
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT) Fritz-Haber-Weg 2 76131 Karlsruhe Germany
| | - Sergei Lebedkin
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT) Herrmann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Michael T. Gamer
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
| | - Andreas C. Boukis
- Institute of Organic ChemistryKarlsruhe Institute of Technology (KIT) Fritz-Haber-Weg 6 76131 Karlsruhe Germany
| | - Florian Weigend
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT) Herrmann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Manfred M. Kappes
- Institute of Physical ChemistryKarlsruhe Institute of Technology (KIT) Fritz-Haber-Weg 2 76131 Karlsruhe Germany
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT) Herrmann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Peter W. Roesky
- Institute of Inorganic ChemistryKarlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
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Seifert TP, Bestgen S, Feuerstein TJ, Lebedkin S, Krämer F, Fengler C, Gamer MT, Kappes MM, Roesky PW. Phosphine-substituted 1,2,3-triazoles as P,C- and P,N-ligands for photoluminescent coinage metal complexes. Dalton Trans 2019; 48:15427-15434. [DOI: 10.1039/c9dt01239g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A series of homo- and hetero-polynuclear coinage metal complexes based on a phosphine-substituted 1,2,3-triazole system was synthesized.
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Affiliation(s)
- Tim P. Seifert
- Institute for Inorganic Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76131 Karlsruhe
- Germany
| | - Sebastian Bestgen
- Institute for Inorganic Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76131 Karlsruhe
- Germany
| | - Thomas J. Feuerstein
- Institute for Inorganic Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76131 Karlsruhe
- Germany
| | - Sergei Lebedkin
- Institute of Nanotechnology
- Karlsruhe Institute of Technology (KIT)
- 76344 Eggenstein-Leopoldshafen
- Germany
| | - Felix Krämer
- Institute for Inorganic Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76131 Karlsruhe
- Germany
| | - Christian Fengler
- Institute for Inorganic Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76131 Karlsruhe
- Germany
| | - Michael T. Gamer
- Institute for Inorganic Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76131 Karlsruhe
- Germany
| | - Manfred M. Kappes
- Institute of Nanotechnology
- Karlsruhe Institute of Technology (KIT)
- 76344 Eggenstein-Leopoldshafen
- Germany
- Institute for Physical Chemistry
| | - Peter W. Roesky
- Institute for Inorganic Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76131 Karlsruhe
- Germany
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Simler T, Feuerstein TJ, Yadav R, Gamer MT, Roesky PW. Access to divalent lanthanide NHC complexes by redox-transmetallation from silver and CO 2 insertion reactions. Chem Commun (Camb) 2018; 55:222-225. [PMID: 30525155 DOI: 10.1039/c8cc08120d] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Through a redox-transmetallation procedure, divalent NHC-LnII (NHC = N-heterocyclic carbene; Ln = Eu, Yb) complexes were obtained from the corresponding NHC-AgI. The lability of the NHC-LnII bond was investigated and treatment with CO2 led to insertion reactions without oxidation of the metal centre. The EuII complex [EuI2(IMes)(THF)3] (IMes = 1,3-dimesitylimidazol-2-ylidene) exhibits photoluminescence with a quantum yield reaching 53%.
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Affiliation(s)
- Thomas Simler
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstr. 15, 76131 Karlsruhe, Germany.
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20
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Müller R, Feuerstein TJ, Trouillet V, Bestgen S, Roesky PW, Barner‐Kowollik C. Cover Feature: Spatially‐Resolved Multiple Metallopolymer Surfaces by Photolithography (Chem. Eur. J. 71/2018). Chemistry 2018. [DOI: 10.1002/chem.201805848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Rouven Müller
- Macromolecular Architectures Institute for Chemical Technology and Polymer Chemistry (ITCP) Karlsruhe Institute of Technology (KIT) Engesserstraße 18 76128 Karlsruhe Germany
| | - Thomas J. Feuerstein
- Institute for Inorganic Chemistry (AOC) Karlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
| | - Vanessa Trouillet
- Institute for Applied Materials (IAM) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
- Karlsruhe Nano Micro Facility (KNMF) Karlsruhe Institute of Technology (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Sebastian Bestgen
- Institute for Inorganic Chemistry (AOC) Karlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
| | - Peter W. Roesky
- Institute for Inorganic Chemistry (AOC) Karlsruhe Institute of Technology (KIT) Engesserstr. 15 76131 Karlsruhe Germany
| | - Christopher Barner‐Kowollik
- Macromolecular Architectures Institute for Chemical Technology and Polymer Chemistry (ITCP) Karlsruhe Institute of Technology (KIT) Engesserstraße 18 76128 Karlsruhe Germany
- School of Chemistry, Physics and Mechanical Engineering Queensland University of Technology (QUT) 2 George Street Brisbane QLD 4000 Australia
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Müller R, Feuerstein TJ, Trouillet V, Bestgen S, Roesky PW, Barner-Kowollik C. Spatially-Resolved Multiple Metallopolymer Surfaces by Photolithography. Chemistry 2018; 24:18933-18943. [PMID: 30357939 DOI: 10.1002/chem.201803966] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Indexed: 12/19/2022]
Abstract
A tetrazole-based photoligation protocol for the spatially-resolved encoding of various defined metallopolymers onto solid surfaces is introduced. By using this approach, fabrication of bi- and trifunctional metallopolymer surfaces with different metal combinations were achieved. Specifically, α-ω-functional copolymers containing bipyridine as well as triphenylphosphine ligands were synthesized through reversible addition-fragmentation chain transfer (RAFT) polymerization, and subsequently metal loaded to afford metallopolymers of the widely-used metals gold, palladium, and platinum. Spatially-resolved surface attachment was achieved by means of a nitrile imine-mediated tetrazole-ene cycloaddition (NITEC) based photoligation protocol, exploiting tethered tetrazoles and metallopolymers equipped with a maleimide chain terminus. Metallopolymer coated surfaces with three different metals were prepared and characterized by time-of-flight secondary ion mass spectrometry (ToF-SIMS) and spatially-resolved X-ray photoelectron spectroscopy (XPS) mapping, supporting the preserved chemical composition of the surface-bound metallopolymers. The established photochemical technology platform for arbitrary spatially-resolved metallopolymer surface designs enables the patterning of multiple metallopolymers onto solid substrates. This allows for the assembly of designer metallopolymer substrates.
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Affiliation(s)
- Rouven Müller
- Macromolecular Architectures, Institute for Chemical Technology and Polymer Chemistry (ITCP), Karlsruhe Institute of Technology (KIT), Engesserstraße 18, 76128, Karlsruhe, Germany
| | - Thomas J Feuerstein
- Institute for Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Vanessa Trouillet
- Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.,Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Sebastian Bestgen
- Institute for Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Peter W Roesky
- Institute for Inorganic Chemistry (AOC), Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131, Karlsruhe, Germany
| | - Christopher Barner-Kowollik
- Macromolecular Architectures, Institute for Chemical Technology and Polymer Chemistry (ITCP), Karlsruhe Institute of Technology (KIT), Engesserstraße 18, 76128, Karlsruhe, Germany.,School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
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22
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Bestgen S, Schoo C, Neumeier BL, Feuerstein TJ, Zovko C, Köppe R, Feldmann C, Roesky PW. Intensely Photoluminescent Diamidophosphines of the Alkaline-Earth Metals, Aluminum, and Zinc. Angew Chem Int Ed Engl 2018; 57:14265-14269. [PMID: 30040153 DOI: 10.1002/anie.201806943] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Indexed: 11/09/2022]
Abstract
The positively charged and weakly polarizable s-block metals commonly do not usually have phosphine ligands in molecular complexes. Herein, we report mono- and dinuclear small diamidophosphine complexes of the alkaline-earth metals Mg, Ca, and Sr, which were prepared from simple precursors and a phosphine-functionalized diamine ligand N,N-bis(2-(diphenyl-phosphino)phenyl)ethane-1,2-diamine (PNHNHP). The alkaline-earth metal based complexes [(PNNP)Mg]2 and [(PNNP)M(thf)3 ] (M=Ca, Sr), exhibit unusual coordination spheres and show bright fluorescence, both in the solid state and in solution. For comparison, the even stronger luminescent Al and Zn complexes [(PNNP)Zn]2 and [(PNNP)AlCl] were prepared. Emission lifetimes in the nanosecond range and high photoluminescence quantum yields up to 93 % are observed at room temperature.
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Affiliation(s)
- Sebastian Bestgen
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany.,Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK
| | - Christoph Schoo
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
| | - B Lilli Neumeier
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
| | - Thomas J Feuerstein
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
| | - Christina Zovko
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
| | - Ralf Köppe
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
| | - Claus Feldmann
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
| | - Peter W Roesky
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131, Karlsruhe, Germany
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Bestgen S, Schoo C, Neumeier BL, Feuerstein TJ, Zovko C, Köppe R, Feldmann C, Roesky PW. Photolumineszierende Diamidophosphankomplexe der Erdalkalimetalle, des Aluminiums und des Zinks. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201806943] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sebastian Bestgen
- Institut für Anorganische Chemie; Karlsruher Institut für Technologie (KIT); Engesserstraße 15 76131 Karlsruhe Germany
- Department of Chemistry; Chemistry Research Laboratory; University of Oxford; 12 Mansfield Road Oxford OX1 3TA UK
| | - Christoph Schoo
- Institut für Anorganische Chemie; Karlsruher Institut für Technologie (KIT); Engesserstraße 15 76131 Karlsruhe Germany
| | - B. Lilli Neumeier
- Institut für Anorganische Chemie; Karlsruher Institut für Technologie (KIT); Engesserstraße 15 76131 Karlsruhe Germany
| | - Thomas J. Feuerstein
- Institut für Anorganische Chemie; Karlsruher Institut für Technologie (KIT); Engesserstraße 15 76131 Karlsruhe Germany
| | - Christina Zovko
- Institut für Anorganische Chemie; Karlsruher Institut für Technologie (KIT); Engesserstraße 15 76131 Karlsruhe Germany
| | - Ralf Köppe
- Institut für Anorganische Chemie; Karlsruher Institut für Technologie (KIT); Engesserstraße 15 76131 Karlsruhe Germany
| | - Claus Feldmann
- Institut für Anorganische Chemie; Karlsruher Institut für Technologie (KIT); Engesserstraße 15 76131 Karlsruhe Germany
| | - Peter W. Roesky
- Institut für Anorganische Chemie; Karlsruher Institut für Technologie (KIT); Engesserstraße 15 76131 Karlsruhe Germany
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Knöfel ND, Schweigert C, Feuerstein TJ, Schoo C, Reinfandt N, Unterreiner AN, Roesky PW. Dimolybdenum Paddlewheel as Scaffold for Heteromultimetallic Complexes: Synthesis and Photophysical Properties. Inorg Chem 2018; 57:9364-9375. [DOI: 10.1021/acs.inorgchem.8b01334] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Joseph K, Mottaghi S, Christ O, Feuerstein TJ, Hofmann UG. When the Ostrich-Algorithm Fails: Blanking Method Affects Spike Train Statistics. Front Neurosci 2018; 12:293. [PMID: 29780301 PMCID: PMC5946007 DOI: 10.3389/fnins.2018.00293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 04/13/2018] [Indexed: 11/13/2022] Open
Abstract
Modern electroceuticals are bound to employ the usage of electrical high frequency (130-180 Hz) stimulation carried out under closed loop control, most prominent in the case of movement disorders. However, particular challenges are faced when electrical recordings of neuronal tissue are carried out during high frequency electrical stimulation, both in-vivo and in-vitro. This stimulation produces undesired artifacts and can render the recorded signal only partially useful. The extent of these artifacts is often reduced by temporarily grounding the recording input during stimulation pulses. In the following study, we quantify the effects of this method, "blanking," on the spike count and spike train statistics. Starting from a theoretical standpoint, we calculate a loss in the absolute number of action potentials, depending on: width of the blanking window, frequency of stimulation, and intrinsic neuronal activity. These calculations were then corroborated by actual high signal to noise ratio (SNR) single cell recordings. We state that, for clinically relevant frequencies of 130 Hz (used for movement disorders) and realistic blanking windows of 2 ms, up to 27% of actual existing spikes are lost. We strongly advice cautioned use of the blanking method when spike rate quantification is attempted. Impact statement Blanking (artifact removal by temporarily grounding input), depending on recording parameters, can lead to significant spike loss. Very careful use of blanking circuits is advised.
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Affiliation(s)
- Kevin Joseph
- Section for Neuroelectronic Systems, Clinic for Neurosurgery, Medical Center- University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Soheil Mottaghi
- Section for Neuroelectronic Systems, Clinic for Neurosurgery, Medical Center- University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Olaf Christ
- Section for Neuroelectronic Systems, Clinic for Neurosurgery, Medical Center- University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas J Feuerstein
- Section for Neuroelectronic Systems, Clinic for Neurosurgery, Medical Center- University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ulrich G Hofmann
- Section for Neuroelectronic Systems, Clinic for Neurosurgery, Medical Center- University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Freiburg Institute for Advanced Studies, University of Freiburg, Freiburg, Germany
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Feuerstein TJ, Poß M, Seifert TP, Bestgen S, Feldmann C, Roesky PW. A highly luminescent octanuclear gold(i) carbide cluster. Chem Commun (Camb) 2017; 53:9012-9015. [PMID: 28787044 DOI: 10.1039/c7cc04171c] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
An octanuclear gold(i) carbide bridged amidinate cluster [Au8{μ3-(η1:η2-CC)}2(Me3SiCCC(NDipp)2)4(tht)2], which is the first gold(i) complex with a μ3-η1:η2carbide coordination, has been synthesized. The cluster shows intense luminescence with notable high quantum yields both in the solid state and in solution.
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Affiliation(s)
- Thomas J. Feuerstein
- Institute of Inorganic Chemistry
- Karlsruhe Institute of Technology
- 76131 Karlsruhe
- Germany
| | - Marieke Poß
- Institute of Inorganic Chemistry
- Karlsruhe Institute of Technology
- 76131 Karlsruhe
- Germany
| | - Tim P. Seifert
- Institute of Inorganic Chemistry
- Karlsruhe Institute of Technology
- 76131 Karlsruhe
- Germany
| | - Sebastian Bestgen
- Institute of Inorganic Chemistry
- Karlsruhe Institute of Technology
- 76131 Karlsruhe
- Germany
| | - Claus Feldmann
- Institute of Inorganic Chemistry
- Karlsruhe Institute of Technology
- 76131 Karlsruhe
- Germany
| | - Peter W. Roesky
- Institute of Inorganic Chemistry
- Karlsruhe Institute of Technology
- 76131 Karlsruhe
- Germany
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Argiti K, Joseph K, Mottaghi S, Feuerstein TJ, Hofmann UG. Deep brain stimulation: increasing efficiency by alternative waveforms. Current Directions in Biomedical Engineering 2016. [DOI: 10.1515/cdbme-2016-0034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractDeep brain stimulation (DBS) is based on the effect of high frequency stimulation (HFS) in neuronal tissue. As a therapy option for patients suffering from e.g. Parkinson’s disease, DBS has been used for decades. Despite the widespread use, the effect of HFS on neurons is not fully investigated. Improving the stimulation efficiency und specificity could increase the efficiency of the INS (internal neuronal stimulator) as well as potentially reduce unwanted side effects. The effect of HFS on the GABAergic system was quantified using whole cell patch clamp electrophysiology during HFS stimulation in cortical human brain slices in vitro. Rectangular, sine, sawtooth and triangular waveforms were applied extracellularly. Since HFS has been hypothesized to increase the activity of the axons of GABAergic interneurons, a decrease in activity can be observed in the pyramidal cells that the interneurons project to. By isolating the incoming non- GABAergic events, we can filter out only the GABAA currents which can be verified using a GABAA antagonist. The results show that all the waveforms effectively increase the GABAA currents. The triangle waveform causes the highest significant increase in the activity which further increases over time after the stimulation was turned off.
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Affiliation(s)
- Katerina Argiti
- 1Section Clin. Neuropharmacology, Medical Center University of Freiburg, Freiburg, Germany
| | - Kevin Joseph
- 2Section Clin. Neuropharmacology and Section Neuroelectronics Systems, Medical Center University of Freiburg, Freiburg, Germany
| | - Soheil Mottaghi
- 3Section Neuroelectronics Systems, Medical Center University of Freiburg, Freiburg, Germany
| | - Thomas J. Feuerstein
- 1Section Clin. Neuropharmacology, Medical Center University of Freiburg, Freiburg, Germany
| | - Ulrich G. Hofmann
- 3Section Neuroelectronics Systems, Medical Center University of Freiburg, Freiburg, Germany
- 4Cluster of Excellence BrainLinks-BrainTools, University of Freiburg, Germany
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Rassner MP, Moser A, Follo M, Joseph K, van Velthoven-Wurster V, Feuerstein TJ. Neocortical GABA release at high intracellular sodium and low extracellular calcium: an anti-seizure mechanism. J Neurochem 2016; 137:177-89. [DOI: 10.1111/jnc.13555] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 01/14/2016] [Accepted: 01/22/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Michael P. Rassner
- Section of Clinical Neuropharmacology of the Department of Neurosurgery; University of Freiburg; Freiburg Germany
| | - Andreas Moser
- Neurochemical Research Group; Department of Neurology; University of Lübeck; Lübeck Germany
- Freiburg Institute for Advanced Studies (FRIAS); University of Freiburg; Freiburg Germany
| | - Marie Follo
- Department of Medicine I; Medical Center - University of Freiburg; Freiburg Germany
| | - Kevin Joseph
- Section of Clinical Neuropharmacology of the Department of Neurosurgery; University of Freiburg; Freiburg Germany
- Section of Neuroelectronic Systems of the Department of Neurosurgery; University of Freiburg; Freiburg Germany
| | | | - Thomas J. Feuerstein
- Section of Clinical Neuropharmacology of the Department of Neurosurgery; University of Freiburg; Freiburg Germany
- Freiburg Institute for Advanced Studies (FRIAS); University of Freiburg; Freiburg Germany
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Ramantani G, Kadish NE, Anastasopoulos C, Brandt A, Wagner K, Strobl K, Mayer H, Schubert-Bast S, Stathi A, Korinthenberg R, Feuerstein TJ, Mader I, van Velthoven V, Zentner J, Schulze-Bonhage A, Bast T. Epilepsy surgery for glioneuronal tumors in childhood: avoid loss of time. Neurosurgery 2015; 74:648-57; discussion 657. [PMID: 24584135 DOI: 10.1227/neu.0000000000000327] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND In contrast to the abundance of seizure outcome reports in epilepsy surgery for glioneuronal tumors in childhood and adolescence, there is a dearth of information regarding cognitive outcomes. OBJECTIVE To investigate the seizure and cognitive outcome of children and adolescents that underwent resective surgery for glioneuronal tumor-associated refractory epilepsy and determine their predictive factors. METHODS We retrospectively analyzed the presurgical findings, resection types, and outcomes over 1.3 to 12.3 years (mean, 7.3) of 29 consecutive patients, who underwent resection in 2000 to 2011. The mean age at epilepsy onset was 7.9 years (range, 0-15.4), the mean age at surgery was 11.7 years (range, 2.6-17.3), and the mean epilepsy duration to surgery was 3.8 years (range, 0.3-15.3). Etiology comprised 13 dysembryoplastic neuroepithelial tumors and 16 gangliogliomas, with additional focal cortical dysplasia in 5 cases. RESULTS Eighty-six percent of children were seizure free 12 months after surgery; at final follow-up, 76% remained seizure free and 62% had discontinued antiepileptic drugs. Gross total resection was related to significantly higher rates of seizure freedom. Higher presurgical cognitive functioning (full-scale IQ, verbal IQ) was related to shorter epilepsy duration to surgery independent of age at epilepsy onset, thus determining postsurgical functioning. Improvements in verbal IQ, performance IQ, and visual memory as well as a trend toward improvement in full-scale IQ were established after surgery. Despite individual losses in full-scale IQ, verbal or visual memory, no deterioration was noted in any cognitive variable on a group level. CONCLUSION Completeness of resection predisposes to favorable outcomes regarding seizure alleviation. Whereas cognitive functioning deteriorates with time in glioneuronal tumor-related refractory epilepsy, surgery is linked to improvement rather than to deterioration on a group level.
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Affiliation(s)
- Georgia Ramantani
- *Epilepsy Centre, University Hospital Freiburg, Freiburg, Germany; ‡Department of General Pediatrics, Children's University Hospital, Heidelberg, Germany; §Division of Neuropediatrics and Muscular Disorders, Department of Pediatrics and Adolescent Medicine, University Hospital Freiburg, Freiburg, Germany; ¶Department of Neuroradiology, University Hospital Freiburg, Freiburg, Germany; ‖Epilepsy Centre Kork, Kehl-Kork, Germany; #Department of Neurosurgery, University Hospital Freiburg, Freiburg, Germany
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Xie Y, Heida T, Stegenga J, Zhao Y, Moser A, Tronnier V, Feuerstein TJ, Hofmann UG. High-frequency electrical stimulation suppresses cholinergic accumbens interneurons in acute rat brain slices through GABABreceptors. Eur J Neurosci 2014; 40:3653-62. [DOI: 10.1111/ejn.12736] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 08/12/2014] [Accepted: 08/25/2014] [Indexed: 12/13/2022]
Affiliation(s)
- Yijing Xie
- Neuroelectronic Systems; Department of Neurosurgery; University Medical Center Freiburg; 79108 Freiburg Germany
- Graduate School for Computing in Medicine and Life Sciences; University of Lübeck; Lübeck Germany
| | - Tjitske Heida
- Biomedical Signals and Systems; University of Twente; Enschede The Netherlands
| | - Jan Stegenga
- Biomedical Signals and Systems; University of Twente; Enschede The Netherlands
| | - Yan Zhao
- Biomedical Signals and Systems; University of Twente; Enschede The Netherlands
| | - Andreas Moser
- Clinic for Neurology; University of Lübeck; Lübeck Germany
| | - Volker Tronnier
- Graduate School for Computing in Medicine and Life Sciences; University of Lübeck; Lübeck Germany
- Clinic for Neurosurgery; University of Lübeck; Lübeck Germany
| | - Thomas J. Feuerstein
- Freiburg Institute for Advanced Studies (FRIAS); University of Freiburg; Freiburg Germany
- Section of Clinical Neuropharmacology; Department of Neurosurgery; University Medical Center Freiburg; Freiburg Germany
| | - Ulrich G. Hofmann
- Neuroelectronic Systems; Department of Neurosurgery; University Medical Center Freiburg; 79108 Freiburg Germany
- Graduate School for Computing in Medicine and Life Sciences; University of Lübeck; Lübeck Germany
- Institute for Signal Processing; University of Lübeck; Lübeck Germany
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Amtage F, Feuerstein TJ, Meier S, Prokop T, Piroth T, Pinsker MO. Hypokinesia upon Pallidal Deep Brain Stimulation of Dystonia: Support of a GABAergic Mechanism. Front Neurol 2013; 4:198. [PMID: 24367353 PMCID: PMC3851850 DOI: 10.3389/fneur.2013.00198] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2013] [Accepted: 11/21/2013] [Indexed: 11/13/2022] Open
Abstract
In the past, many studies have documented the beneficial effects of deep brain stimulation (DBS) in the globus pallidus internus for treatment of primary segmental or generalized dystonia. Recently however, several reports focused on DBS-induced hypokinesia or freezing of gait (FOG) as a side effect in these patients. Here we report on two patients suffering from FOG after successful treatment of their dystonic movement disorder with pallidal high frequency stimulation (HFS). Several attempts to reduce the FOG resulted in worsening of the control of dystonia. In one patient levodopa treatment was initialized which was somewhat successful to relieve FOG. We discuss the possible mechanisms of hypokinetic side effects of pallidal DBS which can be explained by the hypothesis of selective GABA release as the mode of action of HFS. Pallidal HFS is also effective in treating idiopathic Parkinson’s disease as a hypokinetic disorder which at first sight seems to be a paradox. In our view, however, the GABAergic hypothesis can explain this and other clinical observations.
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Affiliation(s)
- Florian Amtage
- Department of Neurology, University Medical Center Freiburg , Freiburg , Germany
| | - Thomas J Feuerstein
- Section of Clinical Neuropharmacology, Department of Neurosurgery, University Medical Center Freiburg , Freiburg , Germany
| | - Simone Meier
- Department of Neurology, University Medical Center Freiburg , Freiburg , Germany
| | - Thomas Prokop
- Department of Stereotactic and Functional Neurosurgery, University Medical Center Freiburg , Freiburg , Germany
| | - Tobias Piroth
- Department of Neurology, University Medical Center Freiburg , Freiburg , Germany
| | - Marcus O Pinsker
- Department of Stereotactic and Functional Neurosurgery, University Medical Center Freiburg , Freiburg , Germany
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Feuerstein TJ. Commentary: Gabapentin-lactam and gamma-aminobutyric acid/lactam analogs: the enigma of their mechanism of action. Int J Oral Maxillofac Implants 2013; 28:e239-42. [PMID: 24066340 DOI: 10.11607/jomi.te03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Affiliation(s)
- Andreas Hafner
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber Weg 6, 76131 Karlsruhe, Germany, and Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Thomas J. Feuerstein
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber Weg 6, 76131 Karlsruhe, Germany, and Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Stefan Bräse
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber Weg 6, 76131 Karlsruhe, Germany, and Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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34
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Rassner MP, van Velthoven-Wurster V, Ramantani G, Feuerstein TJ. Altered transporter-mediated neocortical GABA release in Rasmussen encephalitis. Epilepsia 2013; 54:e41-4. [DOI: 10.1111/epi.12093] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/11/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Michael P. Rassner
- Section of Clinical Neuropharmacology; Department of Neurosurgery; Albert-Ludwigs University; Freiburg; Germany
| | | | - Georgia Ramantani
- Epilepsy Center of the Department of Neurosurgery; Albert-Ludwigs University; Freiburg; Germany
| | - Thomas J. Feuerstein
- Section of Clinical Neuropharmacology; Department of Neurosurgery; Albert-Ludwigs University; Freiburg; Germany
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35
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Kovacs FE, Knop T, Urbanski MJ, Freiman I, Freiman TM, Feuerstein TJ, Zentner J, Szabo B. Exogenous and endogenous cannabinoids suppress inhibitory neurotransmission in the human neocortex. Neuropsychopharmacology 2012; 37:1104-14. [PMID: 22048459 PMCID: PMC3306870 DOI: 10.1038/npp.2011.262] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Activation of CB(1) receptors on axon terminals by exogenous cannabinoids (eg, Δ(9)-tetrahydrocannabinol) and by endogenous cannabinoids (endocannabinoids) released by postsynaptic neurons leads to presynaptic inhibition of neurotransmission. The aim of this study was to characterize the effect of cannabinoids on GABAergic synaptic transmission in the human neocortex. Brain slices were prepared from neocortical tissues surgically removed to eliminate epileptogenic foci. Spontaneous GABAergic inhibitory postsynaptic currents (sIPSCs) were recorded in putative pyramidal neurons using patch-clamp techniques. To enhance the activity of cannabinoid-sensitive presynaptic axons, muscarinic receptors were continuously stimulated by carbachol. The synthetic cannabinoid receptor agonist WIN55212-2 decreased the cumulative amplitude of sIPSCs. The CB(1) antagonist rimonabant prevented this effect, verifying the involvement of CB(1) receptors. WIN55212-2 decreased the frequency of miniature IPSCs (mIPSCs) recorded in the presence of tetrodotoxin, but did not change their amplitude, indicating that the neurotransmission was inhibited presynaptically. Depolarization of postsynaptic pyramidal neurons induced a suppression of sIPSCs. As rimonabant prevented this suppression, it is very likely that it was due to endocannabinods acting on CB(1) receptors. This is the first demonstration that an exogenous cannabinoid inhibits synaptic transmission in the human neocortex and that endocannabinoids released by postsynaptic neurons suppress synaptic transmission in the human brain. Interferences of cannabinoid agonists and antagonists with synaptic transmission in the cortex may explain the cognitive and memory deficits elicited by these drugs.
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Affiliation(s)
- Flora E Kovacs
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Tim Knop
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Michal J Urbanski
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Ilka Freiman
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Thomas M Freiman
- Neurochirurgische Klinik, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Thomas J Feuerstein
- Neurochirurgische Klinik, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Josef Zentner
- Neurochirurgische Klinik, Albert-Ludwigs-Universität, Freiburg i. Br., Germany
| | - Bela Szabo
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Freiburg i. Br., Germany,Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 25, D-79104 Freiburg i. Br., Germany, Tel: +49 761 203 5312, Fax: +49 761 203 5318, E-mail:
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Kammerer M, Fabritius M, Carvalho C, Mülhaupt R, Feuerstein TJ, Trittler R. Valproate release from polycaprolactone implants prepared by 3D-bioplotting. Pharmazie 2011; 66:511-516. [PMID: 21812326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In this study we examined the release kinetics of valproate from polycaprolactone (PCL) implants constructed for local antiepileptic therapy. The PCL implants were produced with a novel 3D-Bioplotting technology. Release kinetics were determined by superfusion of these implants. Valproate was measured in the superfusate fractions with high pressure liquid chromatography (HPLC). The HPLC measurements were linear over a concentration range of 10-500 microg/mL for valproate and the limit of quantification was found to be 9 microg/mL. The HPLC method used is simple, accurate and sensitive. Within the first day, valproate (10% w/w)-PCL implants released already 77% of the maximum possible liberated amount whereas (5% w/w)-PCL implants released only 53%. After four days, 88% of valproate was released from (10% w/w)-PCL implants and 94% valproate from (5% w/w)-PCL implants. When valproate was ground before the 3D-Bioplotting process, only 63% from (10% w/w)-PCL implants was released within the first day. This released amount of ground valproate was significantly lower compared to that which was not ground from the (10% w/w)-PCL implants. After three days of superfusion a total amount of 89% of ground valproate within the implants was released, corresponding to 88% of non-ground valproate after four days. The fast releasing PCL implants can be used to study acute effects of locally applied valproate on epileptogenesis in vivo after initiation of an epileptic focus in an animal model. The corresponding biocompatibility may also be analysed.
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Affiliation(s)
- M Kammerer
- Section of Clinical Neuropharmacology, Department of Neurosurgery, Albert-Ludwigs University, Freiburg, Germany
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Feuerstein TJ, Kammerer M, Lücking CH, Moser A. Selective GABA release as a mechanistic basis of high-frequency stimulation used for the treatment of neuropsychiatric diseases. Naunyn Schmiedebergs Arch Pharmacol 2011; 384:1-20. [PMID: 21533988 DOI: 10.1007/s00210-011-0644-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Accepted: 02/23/2011] [Indexed: 11/28/2022]
Abstract
Electrical high-frequency stimulation (HFS) is applied in many brain areas to treat various clinical syndromes. The nearly identical constellation of stimulation parameters raises the question of a unique mechanism of action of this therapeutic option. The identification of a single HFS mechanism may help to optimize the HFS technology by targeting this single mechanism. Experimentally, only axonal membranes are targets of HFS, but not other membranes of neurons or glial cells. Within all HFS target regions, axons of excitatory glutamatergic and inhibitory GABAergic neurons are present and play roles in all clinical syndromes treated successfully with HFS. Therefore, glutamatergic or GABAergic fibres are likely candidates as mediators of a unique HFS mode of action. The selective involvement of another neuronal fibre type (e.g. monoaminergic, cholinergic, etc.) in the HFS mode of action is highly unlikely since the regional and syndromal dissimilarity of the clinical HFS applications precludes the assumption of such a fibre type as primary HFS site of action. Our recent experimental finding that HFS of human neocortical slices induces the action potential-mediated release of GABA, but not of glutamate, simplifies the possibilities to explain the HFS mode of action, as the explanation now may concentrate on GABAergic axons only. Thus, we are analysing, on the basis of the pathophysiological grounds of the various syndromes treated with deep brain stimulation, whether a selective GABA release is a collective explanation of the mode of action of HFS. We suggest that selective GABA release indeed may needfully and sufficiently explain efficacy and side effects of HFS.
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Affiliation(s)
- Thomas J Feuerstein
- Section of Clinical Neuropharmacology, Department of Neurosurgery, University Hospital, Freiburg, Germany.
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Kammerer M, Brawek B, Freiman TM, Jackisch R, Feuerstein TJ. Effects of antiepileptic drugs on glutamate release from rat and human neocortical synaptosomes. Naunyn Schmiedebergs Arch Pharmacol 2011; 383:531-42. [DOI: 10.1007/s00210-011-0620-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Accepted: 03/02/2011] [Indexed: 11/29/2022]
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Mantovani M, Dooley DJ, Weyerbrock A, Jackisch R, Feuerstein TJ. Differential inhibitory effects of drugs acting at the noradrenaline and 5-hydroxytryptamine transporters in rat and human neocortical synaptosomes. Br J Pharmacol 2010; 158:1848-56. [PMID: 19912224 DOI: 10.1111/j.1476-5381.2009.00478.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Although the amino acid sequences of rat and human 5-hydroxytryptamine (5-HT) and noradrenaline (NA) transporters (i.e. SERT and NET) are highly homologous, species differences exist in the inhibitory effects of drugs acting at these transporters. Therefore, comparison of the potencies of drugs acting at SERT and NET in native human and rat neocortex may serve to more accurately predict their clinical profile. EXPERIMENTAL APPROACH Synaptosomes prepared from fresh human and rat neocortical tissues were used for [(3)H]-5-HT and [(3)H]-NA saturation and competition uptake experiments. The drugs tested included NA reuptake inhibitors (desipramine, atomoxetine and (S,S)-reboxetine), 5-HT reuptake blockers (citalopram, fluoxetine and fluvoxamine) and dual 5-HT/NA reuptake inhibitors (duloxetine and milnacipran). KEY RESULTS In saturation experiments on synaptosomal [(3)H]-5-HT and [(3)H]-NA uptake, the dissociation constants did not indicate species differences although a smaller density of both SERT and NET was observed in human tissues. In competition experiments with the various drugs, marked species differences in their potencies were observed, especially at SERT. The rank order of selectivity ratios (SERT/NET) in human neocortex was as follows: citalopram >or= duloxetine = fluvoxamine >or= fluoxetine > milnacipran > desipramine = atomoxetine > (S,S)-reboxetine. Significant species differences in these ratios were observed for duloxetine, atomoxetine and desipramine. CONCLUSIONS AND IMPLICATIONS This study provides the first compilation of drug potency at native human neocortical SERT and NET. The significant species differences (viz., human vs. rat) in drug potency suggest that the general use of rodent data should be limited to predict clinical efficacy or profile.
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Affiliation(s)
- M Mantovani
- Department of Neurosurgery, University of Freiburg, Freiburg, Germany
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40
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Brawek B, Löffler M, Wagner K, Huppertz HJ, Wendling AS, Weyerbrock A, Jackisch R, Feuerstein TJ. Reactive oxygen species (ROS) in the human neocortex: role of aging and cognition. Brain Res Bull 2009; 81:484-90. [PMID: 19854245 DOI: 10.1016/j.brainresbull.2009.10.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 10/14/2009] [Accepted: 10/15/2009] [Indexed: 12/14/2022]
Abstract
Reactive oxygen species (ROS), formed during normal aerobic metabolism, are involved in signal transduction and cognitive functions, but highly increased ROS concentrations may also have detrimental effects. The aim of the present study was to investigate whether aging and cognitive functions are associated with ROS generation in human neocortex obtained from neurosurgical patients. ROS formation in mitochondria from fresh and re-thawed neocortical specimens was measured by monitoring ROS-mediated conversion of dihydrorhodamine 123 to fluorescent rhodamine 123. The validity of this technique was characterized in rat brain mitochondria. The increase in the concentration-response curve of the complex I inhibitor rotenone on ROS generation, as measured by rhodamine 123 (Rh123) fluorescence, was much more pronounced than that of rotenone on mitochondrial [(3)H]-choline uptake [which indicates changes in the mitochondrial membrane potential (DeltaPsi(M))]. Thus, mitochondrial ROS generation can be shown by Rh123 fluorescence although this fluorescence may also reflect changes in DeltaPsi(M) to some extent. ROS formation in human brain mitochondria positively correlated with the age of patients. Moreover, an age-corrected positive correlation of ROS formation with presurgical cognitive performance was observed. Our data suggest a mild increase in ROS formation with aging possibly reflecting a physiological compensation of mitochondrial function. Furthermore, higher cognitive performances in tests of executive functions may be paralleled by slightly increased ROS levels.
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Affiliation(s)
- Bianca Brawek
- Section of Clinical Neuropharmacology, Department of Neurosurgery, University of Freiburg, D-79106 Freiburg, Germany
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41
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Stoll C, Eltze M, Lambrecht G, Zentner J, Feuerstein TJ, Jackisch R. Functional characterization of muscarinic autoreceptors in rat and human neocortex. J Neurochem 2009; 110:837-47. [DOI: 10.1111/j.1471-4159.2009.06193.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Warren MS, Zerangue N, Woodford K, Roberts LM, Tate EH, Feng B, Li C, Feuerstein TJ, Gibbs J, Smith B. Comparative gene expression profiles of ABC transporters in brain microvessel endothelial cells and brain in five species including human. Pharmacol Res 2009; 59:404-13. [DOI: 10.1016/j.phrs.2009.02.007] [Citation(s) in RCA: 182] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 02/13/2009] [Accepted: 02/14/2009] [Indexed: 11/16/2022]
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Jackisch R, Förster S, Kammerer M, Rothmaier AK, Ehret A, Zentner J, Feuerstein TJ. Inhibitory Potency of Choline Esterase Inhibitors on Acetylcholine Release and Choline Esterase Activity in Fresh Specimens of Human and Rat Neocortex. ACTA ACUST UNITED AC 2009; 16:635-47. [DOI: 10.3233/jad-2009-1008] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Rolf Jackisch
- Institute of Experimental and Clinical Pharmacology and Toxicology, Laboratory of Neuropharmacology, University of Freiburg, Freiburg, Germany
| | - Stefan Förster
- Institute of Experimental and Clinical Pharmacology and Toxicology, Laboratory of Neuropharmacology, University of Freiburg, Freiburg, Germany
| | - Miriam Kammerer
- Institute of Experimental and Clinical Pharmacology and Toxicology, Laboratory of Neuropharmacology, University of Freiburg, Freiburg, Germany
- Department of Neurosurgery, Neurocenter, Freiburg, Germany
| | - Anna K. Rothmaier
- Institute of Experimental and Clinical Pharmacology and Toxicology, Laboratory of Neuropharmacology, University of Freiburg, Freiburg, Germany
| | - Andreas Ehret
- Institute of Experimental and Clinical Pharmacology and Toxicology, Laboratory of Neuropharmacology, University of Freiburg, Freiburg, Germany
| | - Josef Zentner
- Department of Neurosurgery, Neurocenter, Freiburg, Germany
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44
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Snider NT, Sikora MJ, Sridar C, Feuerstein TJ, Rae JM, Hollenberg PF. The endocannabinoid anandamide is a substrate for the human polymorphic cytochrome P450 2D6. J Pharmacol Exp Ther 2008; 327:538-45. [PMID: 18698000 DOI: 10.1124/jpet.108.141796] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Members of the cytochrome P450 (P450) family of drug-metabolizing enzymes are present in the human brain, and they may have important roles in the oxidation of endogenous substrates. The polymorphic CYP2D6 is one of the major brain P450 isoforms and has been implicated in neurodegeneration, psychosis, schizophrenia, and personality traits. The objective of this study was to determine whether the endocannabinoid arachidonoylethanolamide (anandamide) is a substrate for CYP2D6. Anandamide is the endogenous ligand to the cannabinoid receptor CB1, which is also activated by the main psychoactive component in marijuana. Signaling via the CB1 receptor alters sensory and motor function, cognition, and emotion. Recombinant CYP2D6 converted anandamide to 20-hydroxyeicosatetraenoic acid ethanolamide and 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acid ethanolamides (EET-EAs) with low micromolar K(m) values. CYP2D6 further metabolized the epoxides of anandamide to form novel dioxygenated derivatives. Human brain microsomal and mitochondrial preparations metabolized anandamide to form hydroxylated and epoxygenated products, respectively. An inhibitory antibody against CYP2D6 significantly decreased the mitochondrial formation of the EET-EAs. To our knowledge, anandamide and its epoxides are the first eicosanoid-like molecules to be identified as CYP2D6 substrates. Our study suggests that anandamide may be a physiological substrate for brain mitochondrial CYP2D6, implicating this polymorphic enzyme as a potential component of the endocannabinoid system in the brain. This study also offers support to the hypothesis that neuropsychiatric phenotype differences among individuals with genetic variations in CYP2D6 could be ascribable to interactions of this enzyme with endogenous substrates.
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Affiliation(s)
- Natasha T Snider
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109-5632, USA
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45
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Abstract
Presynaptic receptors for dopamine, histamine and serotonin that are located on dopaminergic, histaminergic and sertonergic axon terminals, respectively, function as autoreceptors. Presynaptic receptors also occur as heteroreceptors on other axon terminals. Auto- and heteroreceptors mainly affect Ca(2+) -dependent exocytosis from the receptor-bearing nerve ending. Some additionally subserve other presynaptic functions.Presynaptic dopamine, histamine and serotonin receptors are involved in various (patho)physiological conditions. Examples are the following:Dopamine autoreceptors play a role in Parkinson's disease, schizophrenia and drug addiction. Dopamine heteroreceptors affecting the release of acetylcholine and of amino acid neurotransmitters in the basal ganglia are also relevant for Parkinson's disease. Peripheral dopamine heteroreceptors on postganglionic sympathetic terminals influence heart rate and vascular resistance through modulation of noradrenaline release. Blockade of histamine autoreceptors increases histamine synthesis and release and may support higher CNS functions such as arousal, cognition and learning. Peripheral histamine heteroreceptors on C fiber and on postganglionic sympathetic fiber terminals diminish neuropeptide and noradrenaline release, respectively. Both inhibititory effects are beneficial in myocardial ischemia. The inhibition of neuropeptide release also explains the antimigraine effects of some agonists of presynaptic histamine receptors. Upregulation of presynaptic serotonin autoreceptors is probably involved in the pathogenesis of major depression. Correspondingly, antidepressant treatments can be linked with a reduced density of 5-HT autoreceptors. 5-HT Heteroreceptor activation diminishes acetylcholine and GABA release and may therefore increase anxiety. In the periphery, presynaptic 5-HT heteroreceptor agonists shorten migraine attacks by inhibition of the release of neuropeptides from trigeminal afferents, apart from their constrictive action on meningeal vessels.
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MESH Headings
- Animals
- Dopamine/metabolism
- Dopamine Agents/pharmacology
- Dopamine Agents/therapeutic use
- Histamine Antagonists/pharmacology
- Histamine Antagonists/therapeutic use
- Humans
- Nervous System Diseases/drug therapy
- Receptors, Dopamine/drug effects
- Receptors, Dopamine/metabolism
- Receptors, Dopamine/physiology
- Receptors, Histamine/drug effects
- Receptors, Histamine/metabolism
- Receptors, Histamine/physiology
- Receptors, Presynaptic/drug effects
- Receptors, Presynaptic/metabolism
- Receptors, Presynaptic/physiology
- Receptors, Serotonin/drug effects
- Receptors, Serotonin/metabolism
- Receptors, Serotonin/physiology
- Serotonin Agents/pharmacology
- Serotonin Agents/therapeutic use
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Affiliation(s)
- Thomas J Feuerstein
- Neurochirurgische Universitätsklinik Breisacherstrasse, 64 D - 79106, Freiburg, Germany.
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Abstract
The effectiveness of cannabinoids (CB) in the treatment of pain in patients with multiple sclerosis (MS) varies. The pathogenesis of pain in MS is diverse as are the possible effects of CB at different sites of CB receptors in the peripheral and central nervous system, this may explain the variable impact on individual patients. The aim of this review is to summarize pre-clinical and clinical studies to explain this variability from a neuropharmacological point of view. Future studies are needed to examine specific effects on distinct symptoms in homogenous groups of patients.
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Affiliation(s)
- F S Lienau
- Neurochemical Research Group, Department of Neurology, University of Lübeck, Lübeck, Germany.
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47
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Abstract
Principles of complex mechanisms of action of anticonvulsants including latest reports concerning new antiepileptic drugs (AED) are considered. Different aspects of new anticonvulsant drugs (2nd generation) from preclinical and clinical testing, pharmacokinetics, and mono or combination therapy in children and adults are summarized. In the following condensed synopsis pharmacological and clinical characteristics of gabapentin (GBP), lamotrigine (LTG), levetiracetam (LEV), oxcarbazepine (OXC), pregabalin (PGB) and tiagabine (TGB) as well as topiramate (TPM) and zonisamide (ZNS) are discussed. In addition to the mechanisms of action, pharmacokinetics, interactions, indications and dosages as well as side effects are considered. Important data concerning the effect and tolerability of anticonvulsant drugs can be obtained from controlled studies. In comparison to drugs of the first generation (phenobarbital [PB], primidon [PRD], phenytoin [PHT], carbamazepine [CBZ] and valproic acid [VPA]) the potential for interactions and side effects due to enzyme induction or inhibition is reduced by most of the anticonvulsant drugs of the second generation. New anticonvulsant drugs increase the spectrum of treatment and represent further steps with regard to the optimization of an individual therapy of the epilepsies.
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Affiliation(s)
- H Stefan
- University Clinic Erlangen, Epilepsy Center-Neurological Department, Schwabachanlage 6, D-91054 Erlangen, Germany
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48
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Surges R, Brewster AL, Bender RA, Beck H, Feuerstein TJ, Baram TZ. Regulated expression of HCN channels and cAMP levels shape the properties of the h current in developing rat hippocampus. Eur J Neurosci 2006; 24:94-104. [PMID: 16882011 PMCID: PMC2919221 DOI: 10.1111/j.1460-9568.2006.04880.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The hyperpolarization-activated current (I(h)) contributes to intrinsic properties and network responses of neurons. Its biophysical properties depend on the expression profiles of the underlying hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels and the presence of cyclic AMP (cAMP) that potently and differentially modulates I(h) conducted by HCN1, HCN2 and/or HCN4. Here, we studied the properties of I(h) in hippocampal CA1 pyramidal cells, the developmental evolution of the HCN-subunit isoforms that contribute to this current, and their interplay with age-dependent free cAMP concentrations, using electrophysiological, molecular and biochemical methods. I(h) amplitude increased progressively during the first four postnatal weeks, consistent with the observed overall increased expression of HCN channels. Activation kinetics of the current accelerated during this period, consonant with the quantitative reduction of mRNA and protein expression of the slow-kinetics HCN4 isoform and increased levels of HCN1. The sensitivity of I(h) to cAMP, and the contribution of the slow component to the overall I(h), decreased with age. These are likely a result of the developmentally regulated transition of the complement of HCN channel isoforms from cAMP sensitive to relatively cAMP insensitive. Thus, although hippocampal cAMP concentrations increased over twofold during the developmental period studied, the coordinated changes in expression of three HCN channel isoforms resulted in reduced effects of this signalling molecule on neuronal h currents.
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Affiliation(s)
- Rainer Surges
- Department of Neurology, University Clinics Freiburg, Breisacher Strasse 64, 79106 Freiburg, Germany.
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49
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Mantovani M, Van Velthoven V, Fuellgraf H, Feuerstein TJ, Moser A. Neuronal electrical high frequency stimulation enhances GABA outflow from human neocortical slices. Neurochem Int 2006; 49:347-50. [PMID: 16600434 DOI: 10.1016/j.neuint.2006.02.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Accepted: 02/24/2006] [Indexed: 11/26/2022]
Abstract
Electrical high frequency stimulation of the globus pallidus internus or the subthalamic nucleus has beneficial motor effects in advanced Parkinson's disease. The mechanisms underlying these clinical results remain, however, unclear. From previous studies it is proposed that the gamma-aminobutyric acid (GABA) system is involved in the effectiveness of electrical high frequency stimulation. In these experiments, human neocortical slices were stimulated electrically (130 Hz) in vitro, and GABA outflow was measured after o-phthaldialdehyde sulphite derivatization using HPLC with electrochemical detection. Our results could demonstrate that high frequency stimulation (HFS) significantly increased basal GABA outflow in the presence of submaximal concentrations of the voltage-gated sodium channel opener veratridine. This effect could be abolished by the GABA antagonists bicuculline or picrotoxin. These results suggest that HFS has an activating effect on GABAergic neuronal terminals in human neocortical slices, depending on sodium and chloride influx. Since GABA plays a role in CNS disorders of basal ganglia, anxiety and epilepsy, its neocortical modulation by HFS may be (patho)physiologically relevant.
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Affiliation(s)
- M Mantovani
- Section of Clinical Neuropharmacology, Department of Neurosurgery, University Hospital Freiburg, Breisacherstrasse 64, D-79106 Freiburg, Germany
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50
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Henle F, Leemhuis J, Fischer C, Bock HH, Lindemeyer K, Feuerstein TJ, Meyer DK. Gabapentin-Lactam Induces Dendritic Filopodia and Motility in Cultured Hippocampal Neurons. J Pharmacol Exp Ther 2006; 319:181-91. [PMID: 16844845 DOI: 10.1124/jpet.106.106146] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Gabapentin is currently used as a therapeutic agent against epilepsy as well as neuropathic pain. In contrast to gabapentin, its derivative gabapentin-lactam has a pronounced neuroprotective activity. We have studied in cultured hippocampal neurons whether gabapentin-lactam has also neurotrophic effects. Gabapentin-lactam enhanced the formation of dendritic filopodia, which are necessary for synapse formation. It also induced a network of F-actin-containing neurites. In studies with time lapse microscopy, gabapentin-lactam increased the addition but also the elimination of new branches. Affinity precipitation assays showed that gabapentin-lactam increased the GTP binding of the small GTPases Rac and Cdc42, which facilitate branch addition. Gabapentin-lactam also activated RhoA and phosphatidylinositol 3-kinases. In neurons transfected with dominant-negative RhoA or treated with the RhoA-inactivating C3 toxin, gabapentin-lactam increased the number of dendrites and branches. In the presence of Y-27632, which inhibits Rho kinase, newly added branches induced by gabapentin-lactam were no longer eliminated so that gabapentin-lactam increased the number of branches. Y-27632 [(+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexanecarboxamide] also prevented the gabapentin-lactam induced activation of phosphatidylinositol 3-kinases. The phosphatidylinositol 3-kinase inhibitor LY294002 [2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride] reduced the elimination of newly added branches caused by gabapentin-lactam and thus facilitated branch formation. In contrast to gabapentin-lactam, gabapentin had no effect on dendritic filopodia or motility. The effects exerted by gabapentin-lactam on dendritic arborization may be of potential therapeutic interest.
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Affiliation(s)
- Frank Henle
- Zentrum für Neurowissenschaften, Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität, Albert-Strasse 25, D-79104 Freiburg, Germany
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