1
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Zhang S, Lloveras V, Wu Y, Tolosa J, García-Martínez JC, Vidal-Gancedo J. Fluorescent and Magnetic Radical Dendrimers as Potential Bimodal Imaging Probes. Pharmaceutics 2023; 15:1776. [PMID: 37376224 DOI: 10.3390/pharmaceutics15061776] [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: 04/19/2023] [Revised: 06/05/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Dual or multimodal imaging probes have emerged as powerful tools that improve detection sensitivity and accuracy in disease diagnosis by imaging techniques. Two imaging techniques that are complementary and do not use ionizing radiation are magnetic resonance imaging (MRI) and optical fluorescence imaging (OFI). Herein, we prepared metal-free organic species based on dendrimers with magnetic and fluorescent properties as proof-of-concept of bimodal probes for potential MRI and OFI applications. We used oligo(styryl)benzene (OSB) dendrimers core that are fluorescent on their own, and TEMPO organic radicals anchored on their surfaces, as the magnetic component. In this way, we synthesized six radical dendrimers and characterized them by FT-IR, 1H NMR, UV-Vis, MALDI-TOF, SEC, EPR, fluorimetry, and in vitro MRI. Importantly, it was demonstrated that the new dendrimers present two properties: on one hand, they are paramagnetic and show the ability to generate contrast by MRI in vitro, and, on the other hand, they also show fluoresce emission. This is a remarkable result since it is one of the very few cases of macromolecules with bimodal magnetic and fluorescent properties using organic radicals as the magnetic probe.
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Affiliation(s)
- Songbai Zhang
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Vega Lloveras
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
- CIBER de Bioingeniería, Biomateriales y Nanomedicina, Instituto de Salud Carlos III, Campus UAB, 08193 Bellaterra, Spain
| | - Yufei Wu
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
| | - Juan Tolosa
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Farmacia, Universidad de Castilla-La Mancha, C/José María Sánchez Ibáñez s/n, 02008 Albacete, Spain
- Regional Center for Biomedical Research (CRIB), Universidad de Castilla-La Mancha, C/Almansa 13, 02008 Albacete, Spain
| | - Joaquín C García-Martínez
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Farmacia, Universidad de Castilla-La Mancha, C/José María Sánchez Ibáñez s/n, 02008 Albacete, Spain
- Regional Center for Biomedical Research (CRIB), Universidad de Castilla-La Mancha, C/Almansa 13, 02008 Albacete, Spain
| | - José Vidal-Gancedo
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
- CIBER de Bioingeniería, Biomateriales y Nanomedicina, Instituto de Salud Carlos III, Campus UAB, 08193 Bellaterra, Spain
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2
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Yue Z, Liu J, Baumgarten M, Wang D. Spirobifluorene Mediating the Spin-Spin Coupling of Nitronyl Nitroxide Diradicals. J Phys Chem A 2023; 127:1565-1575. [PMID: 36627248 DOI: 10.1021/acs.jpca.2c06648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
To investigate the mechanism of this spiro conjugation magnetic behavior, we designed and synthesized three diradicals─22'SBF-NN, 44'SBF-NN, and 27SBF-NN. They are bridged by spirobifluorene and nitronyl nitroxide (NN) diradicals as the spin centers. Notably, by SQUID and electron paramagnetic resonance (EPR) zero-field splitting data analyses, the 22'SBF-NN and 27SBF-NN diradicals exhibit intramolecular, distinctly antiferromagnetic (AF) coupling, with 2J(22'SBF-NN)/kB = -5.86 K and 2J(27SBF-NN)/kB = -24.6 K, respectively. The AF of 22'SBF-NN is opposite to that predicted by the spin density alternation rule based on Hund's rule. Diradical intramolecular conjugation coupling bridged by spiro-carbon conjugation is discussed, in which the 22'SBF-NN is smaller than that of 27SBF-NN, corresponding to the room-temperature EPR characterization. This spiro conjugation is weaker than the traditional planar conjugation and generally leads to a weaker spin-spin coupling in the helical biradical molecule. The EPR spectrum of the 44'SBF-NN diradical shows a deformed nine-line curve, indicating intramolecular exchange coupling. The density functional theory calculation gives a very weak coupling constant of 2Jcalc/kB = 0.06 K, with ferromagnetic (FM) interaction as the proof, which is consistent with the spin-polarized prediction. Further analysis of magnetic susceptibility χm and VT-EPR data shows that there is indeed an extremely weak FM interaction in the 44' position diradical. We find the bridge, which is a 44' substituted SBF structure, blocks the conjugation and contains a larger twist in steric hindrance, which also hampers sufficient spin density delocalization, resulting in a much weaker spin coupling interaction. Combined with the analysis of molecular orbital calculation results, the anomalous intramolecular AF coupling mechanism of 22'SBF-NN is further explained.
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Affiliation(s)
- Zheng Yue
- Anhui Key Laboratory of Advanced Building Materials, School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Jin Liu
- Anhui Key Laboratory of Advanced Building Materials, School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China
| | - Martin Baumgarten
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Di Wang
- Anhui Key Laboratory of Advanced Building Materials, School of Materials Science and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China
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3
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Lloveras V, Elías-Rodríguez P, Bursi L, Shirdel E, Goñi AR, Calzolari A, Vidal-Gancedo J. Multifunctional Switch Based on Spin-Labeled Gold Nanoparticles. NANO LETTERS 2022; 22:768-774. [PMID: 35078323 DOI: 10.1021/acs.nanolett.1c04294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The fabrication of multifunctional switches is a fundamental step in the development of nanometer-scale molecular spintronic devices. The anchoring of active organic radicals on gold nanoparticles (AuNPs) surface is little studied and the realization of AuNPs-based switches remains extremely challenging. We report the first demonstration of a surface molecular switch based on AuNPs decorated with persistent perchlorotriphenylmethyl (PTM) radicals. The redox properties of PTM are exploited to fabricate electrochemical switches with optical and magnetic responses, showing high stability and reversibility. Electronic interaction between the radicals and the gold surface is investigated by UV-vis, showing a very broad absorption band in the near-infrared (NIR) region, which becomes more intense when PTMs are reduced to anionic phase. By using multiple experimental techniques, we demonstrate that this interaction is likely favored by the preferentially flat orientation of PTM ligands on the metallic NP surface, as confirmed by first-principles simulations.
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Affiliation(s)
- Vega Lloveras
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Catalonia Spain
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), E-08193 Barcelona, Spain
| | - Pilar Elías-Rodríguez
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Catalonia Spain
| | - Luca Bursi
- CNR-NANO Istituto Nanoscienze, Centro S3, I-41125 Modena, Italy
| | - Ehsan Shirdel
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Catalonia Spain
| | - Alejandro R Goñi
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Catalonia Spain
- ICREA, Passeig Lluís Companys 23, 08010 Barcelona, Spain
| | | | - José Vidal-Gancedo
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Catalonia Spain
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), E-08193 Barcelona, Spain
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4
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Tretyakov EV, Ovcharenko VI, Terent'ev AO, Krylov IB, Magdesieva TV, Mazhukin DG, Gritsan NP. Conjugated nitroxide radicals. RUSSIAN CHEMICAL REVIEWS 2022. [DOI: 10.1070/rcr5025] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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5
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Giaconi N, Sorrentino AL, Poggini L, Lupi M, Polewczyk V, Vinai G, Torelli P, Magnani A, Sessoli R, Menichetti S, Sorace L, Viglianisi C, Mannini M. Stabilization of an Enantiopure Sub-monolayer of Helicene Radical Cations on a Au(111) Surface through Noncovalent Interactions. Angew Chem Int Ed Engl 2021; 60:15276-15280. [PMID: 33904633 PMCID: PMC8362206 DOI: 10.1002/anie.202103710] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/15/2021] [Indexed: 12/16/2022]
Abstract
In the past few years, the chirality and magnetism of molecules have received notable interest for the development of novel molecular devices. Chiral helicenes combine both these properties, and thus their nanostructuration is the first step toward developing new multifunctional devices. Here, we present a novel strategy to deposit a sub‐monolayer of enantiopure thia[4]helicene radical cations on a pre‐functionalized Au(111) substrate. This approach results in both the paramagnetic character and the chemical structure of these molecules being maintained at the nanoscale, as demonstrated by in‐house characterizations. Furthermore, synchrotron‐based X‐ray natural circular dichroism confirmed that the handedness of the thia[4]helicene is preserved on the surface.
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Affiliation(s)
- Niccolò Giaconi
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy.,Department of Industrial Engineering and INSTM Research Unit, University of Florence, Via Santa Marta 3, 50139, Florence, Italy
| | - Andrea Luigi Sorrentino
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy.,Department of Industrial Engineering and INSTM Research Unit, University of Florence, Via Santa Marta 3, 50139, Florence, Italy
| | - Lorenzo Poggini
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy.,Istituto di Chimica dei Composti Organometallici (ICCOM), CNR, Via Madonna del Piano, 10, 50019, Sesto Fiorentino, Italy
| | - Michela Lupi
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
| | - Vincent Polewczyk
- Istituto Officina dei Materiali (IOM), CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, 34149, Trieste, Italy
| | - Giovanni Vinai
- Istituto Officina dei Materiali (IOM), CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, 34149, Trieste, Italy
| | - Piero Torelli
- Istituto Officina dei Materiali (IOM), CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, 34149, Trieste, Italy
| | - Agnese Magnani
- Department of Biotechnology, Chemistry and Pharmacy and INSTM Research Unit, University of Siena, Via Aldo Moro 2, 53100, Siena, Italy
| | - Roberta Sessoli
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
| | - Stefano Menichetti
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
| | - Lorenzo Sorace
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
| | - Caterina Viglianisi
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
| | - Matteo Mannini
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
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6
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Poggini L, Lunghi A, Collauto A, Barbon A, Armelao L, Magnani A, Caneschi A, Totti F, Sorace L, Mannini M. Chemisorption of nitronyl-nitroxide radicals on gold surface: an assessment of morphology, exchange interaction and decoherence time. NANOSCALE 2021; 13:7613-7621. [PMID: 33881100 DOI: 10.1039/d1nr00640a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A combined Tof-SIMS, XPS and STM characterization has been performed to study the deposition of a sulphur-functionalized nitronyl nitroxide radical on Au(111) clearly demonstrating the chemisorption of intact molecules. Continuous -wave EPR characterization showed that the radical molecules maintain their paramagnetic character. Pulsed EPR measurements allowed to determine the decoherence time of the nanostructure at 80 K, which turned out to be comparable to the one measured in frozen solution and longer than previously reported for many radicals and other paramagnetic molecules at much lower temperatures. Furthermore, we conducted a state-of-the-art ab initio molecular dynamics study, suggesting different possible scenarios for chemisorption geometries and predicting the energetically favoured geometry. Calculation of the magnetic properties indicates a partial non-innocent role of the gold surface in determining the magnetic interactions between radicals in packed structures. This suggests that the observed EPR spectrum is to be attributed to low-density domains of disordered radicals interacting via dipolar interactions.
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Affiliation(s)
- Lorenzo Poggini
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, I-50019 Sesto Fiorentino, Italy. and ICCOM-CNR, via Madonna del Piano 10, 50019 Sesto, Fiorentino, Italy.
| | - Alessandro Lunghi
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, I-50019 Sesto Fiorentino, Italy.
| | - Alberto Collauto
- Department of Chemical Sciences and INSTM Research Unit, University of Padua, I-35131 Padova, Italy
| | - Antonio Barbon
- Department of Chemical Sciences and INSTM Research Unit, University of Padua, I-35131 Padova, Italy
| | - Lidia Armelao
- Department of Chemical Sciences and INSTM Research Unit, University of Padua, I-35131 Padova, Italy and Institute of Condensed Matter Chemistry and Technologies for Energy, National Research Council of Italy, ICMATE-CNR, via Marzolo 1, 35131 Padua, Italy and Department of Chemical Sciences and Materials Technologies, National Research Council of Italy, DSCTM - CNR, Piazzale A. Moro 7, 00185 Rome, Italy
| | - Agnese Magnani
- Department of Biotechnologies, Chemistry and Pharmacy, and INSTM Research Unit, University of Siena, I-53100 Siena, Italy
| | - Andrea Caneschi
- DIEF - Department of Industrial Engineering and INSTM Research Unit, University of Florence, Via S. Marta 3, I-50139 Florence, Italy
| | - Federico Totti
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, I-50019 Sesto Fiorentino, Italy.
| | - Lorenzo Sorace
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, I-50019 Sesto Fiorentino, Italy.
| | - Matteo Mannini
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, I-50019 Sesto Fiorentino, Italy.
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7
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Manipulation of Molecular Spin State on Surfaces Studied by Scanning Tunneling Microscopy. NANOMATERIALS 2020; 10:nano10122393. [PMID: 33266045 PMCID: PMC7761235 DOI: 10.3390/nano10122393] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 11/27/2020] [Accepted: 11/27/2020] [Indexed: 11/17/2022]
Abstract
The adsorbed magnetic molecules with tunable spin states have drawn wide attention for their immense potential in the emerging fields of molecular spintronics and quantum computing. One of the key issues toward their application is the efficient controlling of their spin state. This review briefly summarizes the recent progress in the field of molecular spin state manipulation on surfaces. We focus on the molecular spins originated from the unpaired electrons of which the Kondo effect and spin excitation can be detected by scanning tunneling microscopy and spectroscopy (STM and STS). Studies of the molecular spin-carriers in three categories are overviewed, i.e., the ones solely composed of main group elements, the ones comprising 3d-metals, and the ones comprising 4f-metals. Several frequently used strategies for tuning molecular spin state are exemplified, including chemical reactions, reversible atomic/molecular chemisorption, and STM-tip manipulations. The summary of the successful case studies of molecular spin state manipulation may not only facilitate the fundamental understanding of molecular magnetism and spintronics but also inspire the design of the molecule-based spintronic devices and materials.
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8
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Junghoefer T, Nowik-Boltyk EM, de Sousa JA, Giangrisostomi E, Ovsyannikov R, Chassé T, Veciana J, Mas-Torrent M, Rovira C, Crivillers N, Casu MB. Stability of radical-functionalized gold surfaces by self-assembly and on-surface chemistry. Chem Sci 2020; 11:9162-9172. [PMID: 34123165 PMCID: PMC8163401 DOI: 10.1039/d0sc03399e] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 08/10/2020] [Indexed: 11/23/2022] Open
Abstract
We have investigated the radical functionalization of gold surfaces with a derivative of the perchlorotriphenylmethyl (PTM) radical using two methods: by chemisorption from the radical solution and by on-surface chemical derivation from a precursor. We have investigated the obtained self-assembled monolayers by photon-energy dependent X-ray photoelectron spectroscopy. Our results show that the molecules were successfully anchored on the surfaces. We have used a robust method that can be applied to a variety of materials to assess the stability of the functionalized interface. The monolayers are characterized by air and X-ray beam stability unprecedented for films of organic radicals. Over very long X-ray beam exposure we observed a dynamic nature of the radical-Au complex. The results clearly indicate that (mono)layers of PTM radical derivatives have the necessary stability to withstand device applications.
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Affiliation(s)
- Tobias Junghoefer
- Institute of Physical and Theoretical Chemistry, University of Tübingen 72076 Tübingen Germany
| | | | - J Alejandro de Sousa
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Networking Research Center on Bioengineering Biomaterials and Nanomedicine (CIBER-BBN) Campus de la UAB 08193 Bellaterra Spain
- Laboratorio de Electroquímica, Departamento de Química, Facultad de Ciencias, Universidad de los Andes 5101 Mérida Venezuela
| | | | - Ruslan Ovsyannikov
- Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) 12489 Berlin Germany
| | - Thomas Chassé
- Institute of Physical and Theoretical Chemistry, University of Tübingen 72076 Tübingen Germany
| | - Jaume Veciana
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Networking Research Center on Bioengineering Biomaterials and Nanomedicine (CIBER-BBN) Campus de la UAB 08193 Bellaterra Spain
| | - Marta Mas-Torrent
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Networking Research Center on Bioengineering Biomaterials and Nanomedicine (CIBER-BBN) Campus de la UAB 08193 Bellaterra Spain
| | - Concepció Rovira
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Networking Research Center on Bioengineering Biomaterials and Nanomedicine (CIBER-BBN) Campus de la UAB 08193 Bellaterra Spain
| | - Núria Crivillers
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Networking Research Center on Bioengineering Biomaterials and Nanomedicine (CIBER-BBN) Campus de la UAB 08193 Bellaterra Spain
| | - Maria Benedetta Casu
- Institute of Physical and Theoretical Chemistry, University of Tübingen 72076 Tübingen Germany
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9
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Badetti E, Lloveras V, Scaramuzzo FA, Wurst K, Veciana J, Vidal-Gancedo J, Licini G, Zonta C. Tris-pyridylmethylamine (TPMA) complexes functionalized with persistent nitronyl nitroxide organic radicals. Dalton Trans 2020; 49:10011-10016. [PMID: 32643714 DOI: 10.1039/d0dt01553a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The chance to have persistent organic radicals in combination with metals has attracted much interest since it offers the possibility of having new functional molecules with multiple open-shell elements. In this study, we report the synthesis of two tripodal tris(2-pyridyl)methylamine ligands (TPMA) functionalized with nitronyl nitroxide persistent radicals. The newly formed ligands have been used to coordinate zinc(ii), copper(ii), iron(ii) and cobalt(ii). The resulting complexes have been investigated by means of electron paramagnetic resonance (EPR), ESI-MS, FT-IR spectroscopy and X-ray diffraction. An electron reduction of the N-O radical moiety has been observed, depending on the metal used for the formation of the complex and the reaction conditions. We have observed small differences in the EPR spectra depending on the meta or para position of the radical moiety in the complex structure and some antiferromagnetic interactions between the paramagnetic M(ii) ions and the radical species.
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Affiliation(s)
- Elena Badetti
- Department of Chemical Sciences, University of Padova via Marzolo 1, 35131 Padova, Italy
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10
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Lloveras V, Liko F, Pinto LF, Muñoz-Gómez JL, Veciana J, Vidal-Gancedo J. Tuning Spin-Spin Interactions in Radical Dendrimers. Chemphyschem 2018; 19:1895-1902. [PMID: 29744989 DOI: 10.1002/cphc.201800372] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Indexed: 12/15/2022]
Abstract
Two generations of polyphosphorhydrazone (PPH) dendrimers were synthesized and fully functionalized with TEMPO radicals via acrylamido or imino group linkers to evaluate the impact of the linker substitution on the radical-radical interactions. A drastic change in the way that the radicals interacted among them was observed by EPR and CV studies: while radicals in Gn -imino-TEMPO dendrimers presented a strong spin-spin interaction, in the Gn -acrylamido-TEMPO ones they acted mainly as independent radicals. This shows that these interactions could be tuned by the solely substitution of the radical linker, opening the perspective of controlling and modulating the extension of these interactions depending on each application. The chemical properties of the linker strongly influence the spin-spin exchange between pendant radicals.
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Affiliation(s)
- Vega Lloveras
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), campus universitari de Bellaterra, E-, 08193, Cerdanyola del Vallès, Spain
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
| | - Flonja Liko
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), campus universitari de Bellaterra, E-, 08193, Cerdanyola del Vallès, Spain
| | - Luiz F Pinto
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), campus universitari de Bellaterra, E-, 08193, Cerdanyola del Vallès, Spain
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
| | - José L Muñoz-Gómez
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), campus universitari de Bellaterra, E-, 08193, Cerdanyola del Vallès, Spain
| | - Jaume Veciana
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), campus universitari de Bellaterra, E-, 08193, Cerdanyola del Vallès, Spain
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
| | - José Vidal-Gancedo
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), campus universitari de Bellaterra, E-, 08193, Cerdanyola del Vallès, Spain
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Barcelona, Spain
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11
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Ajayakumar MR, Alcón I, Bromley ST, Veciana J, Rovira C, Mas-Torrent M. Direct covalent grafting of an organic radical core on gold and silver. RSC Adv 2017. [DOI: 10.1039/c7ra01686g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A newly designed radical–anchor (R–A) molecule was synthesized and covalently grafted on Ag and Au surface at one atom distance preserving the molecular spin.
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Affiliation(s)
- M. R. Ajayakumar
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC)
- CIBER-BBN
- 08193 Bellaterra
- Spain
| | - I. Alcón
- Departament de Ciència de Materials i Física Química
- Institut de Química Teòrica i Computacional (IQTCUB)
- Universitat de Barcelona
- E-08028 Barcelona
- Spain
| | - S. T. Bromley
- Departament de Ciència de Materials i Física Química
- Institut de Química Teòrica i Computacional (IQTCUB)
- Universitat de Barcelona
- E-08028 Barcelona
- Spain
| | - J. Veciana
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC)
- CIBER-BBN
- 08193 Bellaterra
- Spain
| | - C. Rovira
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC)
- CIBER-BBN
- 08193 Bellaterra
- Spain
| | - M. Mas-Torrent
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC)
- CIBER-BBN
- 08193 Bellaterra
- Spain
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