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Doeven EH, Connell TU, Sinha N, Wenger OS, Francis PS. Electrochemiluminescence of a First-Row d 6 Transition Metal Complex. Angew Chem Int Ed Engl 2024; 63:e202319047. [PMID: 38519420 DOI: 10.1002/anie.202319047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 03/12/2024] [Accepted: 03/22/2024] [Indexed: 03/24/2024]
Abstract
We report the electrochemiluminescence (ECL) of a 3d6 Cr(0) complex ([Cr(LMes)3]; λem=735 nm) with comparable photophysical properties to those of ECL-active complexes of 4d6 or 5d6 precious metal ions. The electrochemical potentials of [Cr(LMes)3] are more negative than those of [Ir(ppy)3] and render the [Cr(LMes)3]* excited state inaccessible through conventional co-reactant ECL with tri-n-propylamine or oxalate. ECL can be obtained, however, through the annihilation route in which potentials sufficient to oxidise and reduce the luminophore are alternately applied. When combined with [Ir(ppy)3] (λem=520 nm), the annihilation ECL of [Cr(LMes)3] was greatly enhanced whereas that of [Ir(ppy)3] was diminished. Under appropriate conditions, the relative intensities of the two spectrally distinct emissions can be controlled through the applied potentials. From this starting point for ECL with 3d6 metal complexes, we discuss some directions for future development.
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Affiliation(s)
- Egan H Doeven
- Centre for Sustainable Bioproducts, Faculty of Science, Engineering and Built Environment, Deakin University Waurn Ponds, Victoria, 3216, Australia
| | - Timothy U Connell
- Centre for Sustainable Bioproducts, Faculty of Science, Engineering and Built Environment, Deakin University Waurn Ponds, Victoria, 3216, Australia
| | - Narayan Sinha
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
- School of Chemical Sciences, Indian Institute of Technology (IIT) Mandi Kamand, Mandi, 175075, Himachal Pradesh, India
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Paul S Francis
- Centre for Sustainable Bioproducts, Faculty of Science, Engineering and Built Environment, Deakin University Waurn Ponds, Victoria, 3216, Australia
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2
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Yue M, He J, Zou C, Chang X, Lu W. Phosphorescent fac-Bis(triarylisocyanide) W(0) and Mo(0) Complexes. Inorg Chem 2024; 63:3267-3282. [PMID: 38307513 DOI: 10.1021/acs.inorgchem.3c03557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2024]
Abstract
Homoleptic W(0) and Mo(0) complexes containing bis(triarylisocyanide) ligands with bulky substituents were synthesized and spectroscopically characterized. Crystallographically determined structures revealed that these complexes are hourglass-like in shape with the tridentate ligands adopting a facial coordination mode to the metal center. These complexes luminesce in fluid solutions and in the solid state. Typically in toluene at 298 K, the two W(0) complexes display the emission maximum (lifetime and quantum yield) at 591 nm (0.83 μs and 0.35) and 628 nm (1.04 μs and 0.39), and similarly, the two Mo(0) complexes display it at 575 nm (0.54 μs and 0.15) and 617 nm (0.56 μs and 0.23). DFT and TDDFT calculations indicated that the low-energy absorption bands of the W(0) and Mo(0) complexes could be metal-to-ligand charge transfer (MLCT) transitions in nature. These complexes exhibited a reversible M+/0 redox couple at -0.70 and -0.63 V vs Fc+/0 for the W(0) complexes and -0.86 and -0.67 V for the Mo(0) complexes. The excited-state reduction potentials were hence estimated to be -2.91 and -2.74 V vs Fc+/0 for the W(0) complexes and -3.10 and -2.81 V vs Fc+/0 for the Mo(0) complexes, indicating that they are potentially strong photoreductants.
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Affiliation(s)
- Mengwei Yue
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China
| | - Jiang He
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China
| | - Chao Zou
- Songshan Lake Materials Laboratory, Functional Coordination Material Group-Frontier Research Center, Dongguan, Guangdong 523808, P. R. China
| | - Xiaoyong Chang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China
| | - Wei Lu
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, P. R. China
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3
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Cerfontaine S, Duez Q, Troian-Gautier L, Barozzino-Consiglio G, Loiseau F, Cornil J, De Winter J, Gerbaux P, Elias B. Efficient Convergent Energy Transfer in a Stereoisomerically Pure Heptanuclear Luminescent Terpyridine-Based Ru(II)-Os(II) Dendrimer. Inorg Chem 2020; 59:14536-14543. [PMID: 32954720 DOI: 10.1021/acs.inorgchem.0c02336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The stereoisomerically pure synthesis of a novel heptanuclear Ru(II)-Os(II) antenna bearing multitopic terpyridine ligands is reported. An unambiguous structural characterization was obtained by 1H NMR spectroscopy and ion mobility spectrometry (IMS-MS). The heptanuclear complex exhibits large molar absorption coefficients (77900 M-1 cm-1 at 497 nm) and undergoes unitary, downhill, convergent energy transfer from the peripheral Ru(II) subunits to the central Os(II) that displays photoluminescence with a lifetime (τ = 161 ns) competent for diffusional excited-state electron transfer reactivity in solution.
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Affiliation(s)
- Simon Cerfontaine
- Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Université catholique de Louvain (UCLouvain), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
| | - Quentin Duez
- Organic Synthesis and Mass Spectrometry Laboratory, University of Mons - UMONS, 23 Place du Parc, B-7000 Mons, Belgium.,Laboratory for Chemistry of Novel Materials, Center of Innovation and Research in Materials and Polymers (CIRMAP) - University of Mons (UMONS), Place du Parc 23, B-7000 Mons, Belgium
| | - Ludovic Troian-Gautier
- Laboratoire de Chimie Organique, Université libre de Bruxelles (ULB), CP 160/06, 50 avenue F.D. Roosevelt, 1050 Brussels, Belgium
| | - Gabriella Barozzino-Consiglio
- Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Université catholique de Louvain (UCLouvain), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
| | | | - Jérôme Cornil
- Laboratory for Chemistry of Novel Materials, Center of Innovation and Research in Materials and Polymers (CIRMAP) - University of Mons (UMONS), Place du Parc 23, B-7000 Mons, Belgium
| | - Julien De Winter
- Organic Synthesis and Mass Spectrometry Laboratory, University of Mons - UMONS, 23 Place du Parc, B-7000 Mons, Belgium
| | - Pascal Gerbaux
- Organic Synthesis and Mass Spectrometry Laboratory, University of Mons - UMONS, 23 Place du Parc, B-7000 Mons, Belgium
| | - Benjamin Elias
- Institut de la Matière Condensée et des Nanosciences (IMCN), Molecular Chemistry, Materials and Catalysis (MOST), Université catholique de Louvain (UCLouvain), Place Louis Pasteur 1, bte L4.01.02, 1348 Louvain-la-Neuve, Belgium
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4
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Farras P, Waller H, Benniston AC. Enhanced Photostability of a Ruthenium(II) Polypyridyl Complex under Highly Oxidizing Aqueous Conditions by Its Partial Inclusion into a Cyclodextrin. Chemistry 2015; 22:1133-40. [DOI: 10.1002/chem.201503485] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 11/11/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Pau Farras
- Molecular Photonics Laboratory; School of Chemistry; Newcastle University; Newcastle upon Tyne NE1 7RU UK
- School of Chemistry; NUI Galway; Galway Ireland
| | - Helen Waller
- Institute for Cell and Molecular Biosciences; Medical School; Newcastle University; Newcastle upon Tyne NE2 4HH UK
| | - Andrew C. Benniston
- Molecular Photonics Laboratory; School of Chemistry; Newcastle University; Newcastle upon Tyne NE1 7RU UK
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5
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Zhang Y, Lai L, Cai P, Cheng GZ, Xu XM, Liu Y. Synthesis, characterization and anticancer activity of dinuclear ruthenium(ii) complexes linked by an alkyl chain. NEW J CHEM 2015. [DOI: 10.1039/c5nj00582e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Anticancer activity of three novel ruthenium complexes was studied and the cytotoxicity increased with the increase of the amount of methylene in the bridging ligands.
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Affiliation(s)
- Yan Zhang
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan
- China
| | - Lu Lai
- College of Chemistry and Environmental Engineering
- Yangtze University
- Jingzhoun
- China
| | - Ping Cai
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan
- China
| | - Gong-Zhen Cheng
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan
- China
| | - Xi-Ming Xu
- Cancer Center
- Renmin Hospital of Wuhan University
- Wuhan
- China
| | - Yi Liu
- College of Chemistry and Molecular Sciences
- Wuhan University
- Wuhan
- China
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Arockia Samy N, Alexander V. A new dinucleating bridging ligand 1,2-bis(2-(1H-imidazo[4,5-f]-[1,10]phenanthrolin-2-yl)phenoxy)ethane and its dinuclear ruthenium(II) complexes: Syntheses, characterization, luminescence, and electrochemical properties. Inorganica Chim Acta 2012. [DOI: 10.1016/j.ica.2011.12.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Barbante GJ, Hogan CF, Wilson DJD, Lewcenko NA, Pfeffer FM, Barnett NW, Francis PS. Simultaneous control of spectroscopic and electrochemical properties in functionalised electrochemiluminescent tris(2,2′-bipyridine)ruthenium(ii) complexes. Analyst 2011; 136:1329-38. [DOI: 10.1039/c0an00952k] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Samy NA, Alexander V. New star-shaped trinuclear Ru(ii) polypyridine complexes of imidazo[4,5-f][1,10]phenanthroline derivatives: syntheses, characterization, photophysical and electrochemical properties. Dalton Trans 2011; 40:8630-42. [DOI: 10.1039/c1dt10811e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Ng Z, Loh KP, Li L, Ho P, Bai P, Yip JHK. Synthesis and electrical characterization of oligo(phenylene ethynylene) molecular wires coordinated to transition metal complexes. ACS NANO 2009; 3:2103-14. [PMID: 19639949 DOI: 10.1021/nn900570v] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Organometallic wires are interesting alternatives to conventional molecular wires based on a pure organic system because of the presence of d orbitals in the transition metal complex. However, synthetic problems, such as decreased stability of the compounds when labile metal complexes are present, often impede their isolation in a pure state and preclude a rapid development of such hybrid molecular wires. In this work, we show that preassembled self-assembled monolayers (SAM) based on pyridine-terminated 1-((4-acetylthiophenyl)ethynyl)-4-((4-pyridyl)ethynyl)benzene can act as a template for the architectural build up of a second layer of transition metal complexes to form an array of organometallic molecular wires on gold. Ru(II)(terpy)(bipy)(2+) (terpy = 2,2':6',2''-terpyridine and bipy = 2,2'-bipyridine) or cyclometalated Pt(II)(pbipy) (pbipy = 6-phenyl-2,2'-bipyridine) were axially coordinated onto the organic SAM via its terminal pyridinium moieties. Current-voltage studies show that the electronic coupling between the transition metal and organic wire produces a molecular wire that exhibits higher conductance than the original organic chain. The presence of the transition metal complexes in the hybrid molecular wire introduces distinctive negative differential resistance (NDR) effects.
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Affiliation(s)
- Zhaoyue Ng
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
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10
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Velayudham M, Rajkumar M, Rajagopal S, Ramamurthy P. Synthesis, characterization, electrochemical and photophysical properties of bimetallic complexes of rhenium(I) and osmium(II). Polyhedron 2008. [DOI: 10.1016/j.poly.2008.07.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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11
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Nikolaou S, Toma HE. A Convergent Approach for the Generation of Dendrimers Containing the [Ru3O(CH3COO)6] Electroactive Core. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200800079] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Lazarides T, Barbieri A, Sabatini C, Barigelletti F, Adams H, Ward MD. Photoinduced energy transfer between Re(I) and Ru(II) termini connected through a new exo-ditopic bis-phenanthroline ligand fused to a central macrocycle spacer: Synthesis, structure, and electrochemical and photophysical properties of a heterodinuclear complex. Inorganica Chim Acta 2007. [DOI: 10.1016/j.ica.2006.04.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Conventional and metal-directed synthesis of homodinuclear and heterotrinuclear complexes of homoditopic and heteroditopic ligands incorporating bpy and tpy metal-binding domains. Polyhedron 2006. [DOI: 10.1016/j.poly.2005.07.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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14
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Constable EC, Handel RW, Housecroft CE, Farràn Morales A, Ventura B, Flamigni L, Barigelletti F. Metal-Directed Synthesis and Photophysical Studies of Trinuclear V-Shaped and Pentanuclear X-Shaped Ruthenium and Osmium Metallorods and Metallostars Based upon 4′-(3,5-Dihydroxyphenyl)-2,2′:6′,2′′-terpyridine Divergent Units. Chemistry 2005; 11:4024-34. [PMID: 15861472 DOI: 10.1002/chem.200500119] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A new series of V-shaped trinuclear metallorods and X-shaped pentanuclear metallostars has been prepared by the reaction of metal complexes bearing pendant phenolic functionalities with complexes containing electrophilic ligands. Specifically, {M(tpy)2} motifs (M=Ru or Os; tpy=2,2':6',2''-terpyridine) bearing one or two pendant 3,5-dihydroxyphenyl substituents at the 4-position of the central ring of the tpy have been reacted with the complexes [Ru(tpy)(Xtpy)]2+ (X=Cl or Br) to form new ether-linked species. The energy transfer from ruthenium to osmium in these complexes has been investigated in detail and the efficiency of transfer shown to be highly temperature dependent; the energy transfer is highly efficient at low temperature, whereas at room temperature nonradiative and nontransfer deactivation of the excited {Ru(tpy)2}* domains is most significant.
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Affiliation(s)
- Edwin C Constable
- Department of Chemistry, University of Basel, Spitalstrasse 51, 4056 Basel, Switzerland.
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15
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Bergman SD, Goldberg I, Barbieri A, Kol M. Mononuclear and dinuclear complexes of isoeilatin. Inorg Chem 2005; 44:2513-23. [PMID: 15792490 DOI: 10.1021/ic050002q] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This work describes the synthesis and characterization of mononuclear and dinuclear Ru(II) and Os(II) complexes based on the symmetrical bridging ligand isoeilatin (1). The crystal structure of 1.[HCl]2 consists of layers of tightly pi-stacked molecules of the biprotonated isoeilatin. The mononuclear complexes [Ru(bpy)2(ieil)]2+ (2(2+)) and [Os(bpy)2(ieil)]2+ (3(2+)) form discrete dimers in solution held together by face-selective pi-stacking interactions via the isoeilatin ligand. Coordination of a second metal fragment does not hinder the pi-stacking completely, as demonstrated by the concentration dependence of the 1H NMR spectra of the dinuclear complexes [{Ru(bpy)2}2{mu-ieil}]4+ (4(4+)), [{Os(bpy)2}2{mu-ieil}]4+ (5(4+)), and [{Ru(bpy)2}{mu-ieil}{Os(bpy)2}]4+ (6(4+)) and supported by the solid-state structure of meso-4.[Cl]4. The bridging isoeilatin ligand conserves its planarity even upon coordination of a second metal fragment, as demonstrated in the solid-state structures of meso-4.[Cl]4, meso-4.[PF6]4, and meso-5.[PF6]4. All of the dinuclear complexes exhibit a preference (3/2-3/1) for the formation of the heterochiral as opposed to the homochiral diastereoisomer. Absorption spectra of the mononuclear complexes feature a low-lying dpi(M) --> pi*iel MLCT band around 600 nm that shifts to beyond 700 nm upon coordination of a second metal fragment. Cyclic and square-wave voltammetry measurements of the complexes exhibit two isoeilatin-based reduction waves that are substantially anodically shifted compared to [M(bpy)3]2+ (M = Ru, Os). Luminescence spectra, quantum yields, and lifetime measurements at room temperature and at 77 K demonstrate that the complexes exhibit 3MLCT emission that occurs in the IR region between 950 and 1300 nm. Both the electrochemical and photophysical data are consistent with the low-lying pi orbital of the isoeilatin ligand. The dinuclear complexes exhibit two reversible, well-resolved, metal-centered oxidation waves, despite the chemical equivalence of the two metal centers, indicating a significant metal-metal interaction mediated by the bridging isoeilatin ligand.
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Affiliation(s)
- Sheba D Bergman
- The School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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16
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Reger DL, Watson RP, Smith MD, Pellechia PJ. Bitopic Phenylene-Linked Bis(pyrazolyl)methane Ligands: Preparation and Supramolecular Structures of Hetero- and Homobimetallic Complexes Incorporating Organoplatinum(II) and Tricarbonylrhenium(I) Centers. Organometallics 2005. [DOI: 10.1021/om049112f] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel L. Reger
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
| | - Russell P. Watson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
| | - Mark D. Smith
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
| | - Perry J. Pellechia
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
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17
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Haberhauer G, Oeser T, Rominger F. A widely applicable concept for predictable induction of preferred configuration in C3-symmetric systems. Chem Commun (Camb) 2005:2799-801. [PMID: 15928762 DOI: 10.1039/b502158h] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Starting from a single chiral platform a widely applicable concept to introduce the preferred configuration of octahedral and tetrahedral centres in C3-symmetric systems is described.
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Affiliation(s)
- Gebhard Haberhauer
- Organisch-Chemisches Institut, Universitat Heidelberg, Im Neuenheimer Feld 270, D-69120 Heidelberg, Germany.
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18
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Bergman SD, Goldberg I, Barbieri A, Barigelletti F, Kol M. Mononuclear and Dinuclear Complexes of Dibenzoeilatin: Synthesis, Structure, and Electrochemical and Photophysical Properties. Inorg Chem 2004; 43:2355-67. [PMID: 15046512 DOI: 10.1021/ic0354062] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This work describes a study of Ru(II) and Os(II) polypyridyl complexes of the symmetrical, fused-aromatic bridging ligand dibenzoeilatin (1). The synthesis, purification, and structural characterization by NMR of the mononuclear complexes [Ru(bpy)(2)(dbneil)](2+) (2), [Ru(tmbpy)(2)(dbneil)](2+) (3), and [Os(bpy)(2)(dbneil)](2+) (4), the homodinuclear complexes [[Ru(bpy)(2)](2)[micro-dbneil]](4+) (5), [[Ru(tmbpy)(2)](2)[micro-dbneil]](4+) (6), and [[Os(bpy)(2)](2)[micro-dbneil]](4+) (7), and the heterodinuclear complex [[Ru(bpy)(2)][micro-dbneil][Os(bpy)(2)]](4+) (8) are described, along with the crystal structures of 4, 6, and 7. Absorption spectra of the mononuclear complexes feature a low-lying MLCT band around 600 nm. The coordination of a second metal fragment results in a dramatic red shift of the MLCT band to beyond 700 nm. Cyclic and square wave voltammograms of the mononuclear complexes exhibit one reversible metal-based oxidation, as well as several ligand-based reduction waves. The first two reductions, attributed to reduction of the dibenzoeilatin ligand, are substantially anodically shifted compared to [M(bpy)(3)](2+) (M = Ru, Os), consistent with the low-lying pi orbital of dibenzoeilatin. The dinuclear complexes exhibit two reversible, well-resolved, metal-centered oxidation waves, despite the chemical equivalence of the two metal centers, indicating a significant metal-metal interaction mediated by the conjugated dibenzoeilatin ligand. Luminescence spectra, quantum yield, and lifetime measurements at room temperature in argon-purged acetonitrile have shown that the complexes exhibit (3)MLCT emission, which occurs in the IR-region between 950 and 1300 nm. The heterodinuclear complex 8 exhibits luminescence only from the Ru-based fragment, the intensity of which is less than 1% of that observed in the corresponding homodinuclear complex 5; no emission from the Os-based unit is observed, and an intramolecular quenching constant of k(q) > or = 3 x10(9) s(-)(1) is evaluated. The nature of the quenching process is briefly discussed.
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Affiliation(s)
- Sheba D Bergman
- The School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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19
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Chao H, Qiu ZR, Cai LR, Zhang H, Li XY, Wong KS, Ji LN. Mono-, Di-, and Tetranuclear Ruthenium(II) Complexes Containing 3-(Pyridin-2-yl)-as-triazino[5,6-f]1,10-phenanthroline: Synthesis, Characterization, and Electrochemical and Photophysical Properties. Inorg Chem 2003; 42:8823-30. [PMID: 14686863 DOI: 10.1021/ic034769z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mono-, di-, and tetranuclear Ru(II) polypyridine complexes based on the bridging ligand pdtp, where pdtp is 3-(pyridin-2-yl)-as-triazino[5,6-f]1,10-phenanthroline, have been synthesized and characterizated. This asymmetric bridging ligand is composed of two nonequivalent coordinating sites: one involves the phenanthroline moiety, and the other one involves the pyridyltriazine moiety. Electrochemical data show that the first redox process in these complexes is pdtp based and the metal-metal interaction in di- and tetranuclear complexes is very weak. The two oxidations (+1.41 and +1.56 V vs SCE) observed in dinuclear complex 2 are mainly ascribed to the different coordination environments of two metal centers. Absorption spectra are essentially the sum of the spectra of the component monometallic species. The emission spectra are measured both at room temperature and at 80 K in a 4:1 (v/v) EtOH/MeOH matrix. The complexes all display luminescence properties which are close to that featured by the parent [Ru(phen)(3)](2+) species. It is also noted that center-to-periphery energy transfer occurs in the dendritic tetranuclear complex 3.
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Affiliation(s)
- Hui Chao
- State Key Laboratory of Optoelectronic Materials and Technologies/Department of Chemistry, Zhongshan University, Guangzhou 510275, P. R. China.
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