1
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Peeks MD, Tait CE, Neuhaus P, Fischer GM, Hoffmann M, Haver R, Cnossen A, Harmer JR, Timmel CR, Anderson HL. Electronic Delocalization in the Radical Cations of Porphyrin Oligomer Molecular Wires. J Am Chem Soc 2017; 139:10461-10471. [PMID: 28678489 PMCID: PMC5543395 DOI: 10.1021/jacs.7b05386] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The radical cations of a family of π-conjugated porphyrin arrays have been investigated: linear chains of N = 1-6 porphyrins, a 6-porphyrin nanoring and a 12-porphyrin nanotube. The radical cations were generated in solution by chemical and electrochemical oxidation, and probed by vis-NIR-IR and EPR spectroscopies. The cations exhibit strong NIR bands at ∼1000 nm and 2000-5000 nm, which shift to longer wavelength with increasing oligomer length. Analysis of the NIR and IR spectra indicates that the polaron is delocalized over 2-3 porphyrin units in the linear oligomers. Some of the IR vibrational bands are strongly intensified on oxidation, and Fano-type antiresonances are observed when activated vibrations overlap with electronic transitions. The solution-phase EPR spectra of the radical cations have Gaussian lineshapes with linewidths proportional to N-0.5, demonstrating that at room temperature the spin hops rapidly over the whole chain on the time scale of the hyperfine coupling (ca. 100 ns). Direct measurement of the hyperfine couplings through electron-nuclear double resonance (ENDOR) in frozen solution (80 K) indicates distribution of the spin over 2-3 porphyrin units for all the oligomers, except the 12-porphyrin nanotube, in which the spin is spread over about 4-6 porphyrins. These experimental studies of linear and cyclic cations give a consistent picture, which is supported by DFT calculations and multiparabolic modeling with a reorganization energy of 1400-2000 cm-1 and coupling of 2000 cm-1 for charge transfer between neighboring sites, placing the system in the Robin-Day class III.
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Affiliation(s)
- Martin D Peeks
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom
| | - Claudia E Tait
- Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford , Oxford OX1 3QR, United Kingdom
| | - Patrik Neuhaus
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom
| | - Georg M Fischer
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom
| | - Markus Hoffmann
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom
| | - Renée Haver
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom
| | - Arjen Cnossen
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom
| | - Jeffrey R Harmer
- Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford , Oxford OX1 3QR, United Kingdom
| | - Christiane R Timmel
- Centre for Advanced Electron Spin Resonance, Department of Chemistry, University of Oxford , Oxford OX1 3QR, United Kingdom
| | - Harry L Anderson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford OX1 3TA, United Kingdom
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2
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Harper SR, Pfrunder MC, Esdaile LJ, Jensen P, McMurtrie JC, Arnold DP. Synthetic, Structural, and Spectroscopic Studies of Bis(porphyrinzinc) Complexes Linked by Two-Atom Conjugating Bridges. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500183] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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3
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Shrestha K, González-Delgado JM, Blew JH, Jakubikova E. Electronic Structure of Covalently Linked Zinc Bacteriochlorin Molecular Arrays: Insights into Molecular Design for NIR Light Harvesting. J Phys Chem A 2014; 118:9901-13. [DOI: 10.1021/jp507749c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Kushal Shrestha
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Jessica M. González-Delgado
- Department
of Chemistry, University of Puerto Rico, Rio Piedras Campus, San Juan, Puerto Rico 00931, United States
| | - James H. Blew
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Elena Jakubikova
- Department
of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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4
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Rintoul L, Harper SR, Arnold DP. A systematic theoretical study of the electronic structures of porphyrin dimers: DFT and TD-DFT calculations on diporphyrins linked by ethane, ethene, ethyne, imine, and azo bridges. Phys Chem Chem Phys 2014; 15:18951-64. [PMID: 24097279 DOI: 10.1039/c3cp53396d] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Theoretical calculations of the geometries, electronic structures and electronic absorption spectra of a series of covalently-linked porphyrin dimers are reported. The diporphyrins comprise 5,10,15-triphenylporphyrinatozinc(II) (ZnTriPP) units linked through the meso carbons by two-atom bridges, namely 1,2-ethanediyl (1), trans-1,2-ethenediyl (2), ethynediyl (3), 1,2-iminomethenediyl (4), and transdiazenediyl (5). The structures were optimised in toluene solvent by Density Functional Theory (DFT), using the integral equation formalism variant of the polarizable continuum model. The calculations were performed using the B3LYP functional and the 6-31G(d,p) basis set. The complete molecules were modelled, with no substitution of smaller groups on the periphery. In parallel, the compounds 2–5 were prepared by known or novel synthetic routes, to enable comparisons of experimental electronic absorption spectra with those calculated using time dependent-DFT at the same level of theory. As the ethane dimer 1 is not yet synthetically accessible, the model monomer meso-2-phenylethylZnTriPP was used for comparisons with the theoretical predictions. The results form a self-consistent set, enabling for the first time legitimate comparisons of the electronic structures of the series, especially regarding the degree to which the porphyrin p-systems interact by conjugation across the bridges. The theoretical calculations of the electronic transitions match the observed spectra in toluene to a remarkable degree, especially with respect to the peak maximum of the Q band, which represents to a large degree the energy of the HOMO–LUMO transition. The imine 4 is intrinsically polar due to the asymmetric bridge, and the HOMO is located almost exclusively on the ZnTriPP unit attached to the nitrogen of the imine, and the LUMO on the C-attached ring. Thus the Q-band transition is mapped as a comprehensive charge-transfer from the former ring to the latter. This may have consequences for the non-linear optical properties of the system. The azoporphyrin 5 exhibits the largest splittings between the interacting MOs via the conjugated bridge, vindicating a prediction by Anderson and co-workers in 2002, and confirmed experimentally by our synthesis of 5. The collected results also indicate that this level of theory is more thanadequate as a model with which to handle these large delocalised molecules.
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Affiliation(s)
- Llew Rintoul
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane, 4001, Australia.
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5
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Hartnell RD, Yoneda T, Mori H, Osuka A, Arnold DP. The Marriage of Peripherally Metallated and Directly Linked Porphyrins: Bromidobis(phosphine)platinum(II) as a Cation‐Stabilizing Substituent on Directly Linked and Fused Triply Linked Diporphyrins. Chem Asian J 2013; 8:2670-9. [DOI: 10.1002/asia.201300633] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 05/27/2013] [Indexed: 12/13/2022]
Affiliation(s)
- Regan D. Hartnell
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, G.P.O. Box 2434, Brisbane 4001 (Australia), Fax: (+61) 7‐3138‐2482
| | - Tomoki Yoneda
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo‐ku, Kyoto, 606‐8502 (Japan), Fax: (+81) 75‐753‐3970
| | - Hirotaka Mori
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo‐ku, Kyoto, 606‐8502 (Japan), Fax: (+81) 75‐753‐3970
| | - Atsuhiro Osuka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo‐ku, Kyoto, 606‐8502 (Japan), Fax: (+81) 75‐753‐3970
| | - Dennis P. Arnold
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, G.P.O. Box 2434, Brisbane 4001 (Australia), Fax: (+61) 7‐3138‐2482
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6
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Tsuchiya T, Shrestha K, Jakubikova E. Orbital Analysis and Excited-State Calculations in an Energy-Based Fragmentation Method. J Chem Theory Comput 2013; 9:3350-63. [DOI: 10.1021/ct400025a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takashi Tsuchiya
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United
States
| | - Kushal Shrestha
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United
States
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United
States
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7
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Mai C, Huang Y, Chiu C, Lin H, Lin Y, Yeh C. Switchable Interporphyrin Interaction in an Anthraquinone‐Bridged Porphyrin Dimer. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.201300149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Chi‐Lun Mai
- Department of Chemistry and Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung 402, Taiwan
| | - Yi‐Lin Huang
- Department of Chemistry and Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung 402, Taiwan
| | - Chien‐Lan Chiu
- Department of Chemistry and Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung 402, Taiwan
| | - Hsin‐Yu Lin
- Department of Chemistry and Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung 402, Taiwan
| | - You‐Shiang Lin
- Department of Chemistry and Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung 402, Taiwan
| | - Chen‐Yu Yeh
- Department of Chemistry and Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung 402, Taiwan
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8
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Locos O, Bašić B, McMurtrie JC, Jensen P, Arnold DP. Homo- and Heteronuclear meso,meso-(E)-Ethene-1,2-diyl-Linked Diporphyrins: Preparation, X-ray Crystal Structure, Electronic Absorption and Emission Spectra and Density Functional Theory Calculations. Chemistry 2012; 18:5574-88. [DOI: 10.1002/chem.201102995] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Indexed: 11/06/2022]
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9
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She C, Easwaramoorthi S, Kim P, Hiroto S, Hisaki I, Shinokubo H, Osuka A, Kim D, Hupp JT. Excess Polarizability Reveals Exciton Localization/Delocalization Controlled by Linking Positions on Porphyrin Rings in Butadiyne-Bridged Porphyrin Dimers. J Phys Chem A 2010; 114:3384-90. [DOI: 10.1021/jp908767x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chunxing She
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Shanmugam Easwaramoorthi
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Pyosang Kim
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Satoru Hiroto
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Ichiro Hisaki
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Hiroshi Shinokubo
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Atsuhiro Osuka
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Dongho Kim
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Joseph T. Hupp
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, Spectroscopy Laboratory for Functional π-Electronic Systems and Department of Chemistry, Yonsei University, Seoul 120-749, Korea, and Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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10
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She C, Lee SJ, McGarrah JE, Vura-Weis J, Wasielewski MR, Chen H, Schatz GC, Ratner MA, Hupp JT. Photoinduced electron transfer from rail to rung within a self-assembled oligomeric porphyrin ladder. Chem Commun (Camb) 2010; 46:547-9. [DOI: 10.1039/b916392a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Zhang Y, Cai X, Qi D, Yao P, Bian Y, Jiang J. Methyloxy Substituted Heteroleptic Bis(phthalocyaninato) Yttrium Complexes: Density Functional Calculations. Chemphyschem 2008; 9:781-92. [DOI: 10.1002/cphc.200700843] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Makarov SG, Piskunov AV, Suvorova ON, Schnurpfeil G, Domrachev GA, Wöhrle D. Near-Infrared Absorbing Ligand-Oxidized Dinuclear Phthalocyanines. Chemistry 2007; 13:3227-33. [PMID: 17201005 DOI: 10.1002/chem.200601164] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Ligand-oxidized annulated dinuclear phthalocyanine zinc(II) and lithium(I) complexes absorbing in the NIR region (lambda=1000-2200 nm) with high extinction coefficients are described. Analogous mononuclear Pc complexes were used for comparison. The oxidized Pcs were characterized in solution by electronic absorption, EPR and NMR spectra. The NIR transitions were explained by using MO diagrams calculated semiempirically. The reversible oxidation behavior of the phthalocyanine complexes was also estimated by cyclic voltammetry. These new extremely long wavelength absorbing phthalocyanines are interesting as materials with new electronic properties.
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Affiliation(s)
- Sergey G Makarov
- Institut für Organische und Makromolekulare Chemie Universität Bremen, P.O. Box 330440, 28334 Bremen, Germany
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13
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Esdaile LJ, Jensen P, McMurtrie JC, Arnold DP. Azoporphyrin: The Porphyrin Analogue of Azobenzene. Angew Chem Int Ed Engl 2007; 46:2090-3. [PMID: 17278161 DOI: 10.1002/anie.200604658] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Louisa J Esdaile
- School of Physical and Chemical Sciences, Queensland University of Technology, G.P.O. Box 2434, Brisbane 4001, Australia
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14
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Esdaile L, Jensen P, McMurtrie J, Arnold D. Azoporphyrin: The Porphyrin Analogue of Azobenzene. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200604658] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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15
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Santi S, Orian L, Durante C, Bisello A, Benetollo F, Crociani L, Ganis P, Ceccon A. Tuning the Electronic Communication in Heterobimetallic Mixed-Valence Ions of (1-Ferrocenyl)- and (2-Ferrocenyl)indenyl Rhodium Isomers. Chemistry 2007; 13:1955-68. [PMID: 17171728 DOI: 10.1002/chem.200600724] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A series of heterobimetallic complexes of general structure [RhL(2){eta(5)-(2-ferrocenyl)indenyl}] (L(2)=cod, nbd, L=CO; cod=cyclooctadiene; nbd=norbornadiene) has been synthesised with the aim of tuning the metal-metal interaction in their mixed-valence ions generated both by chemical and electrochemical oxidation, and the results are compared with those obtained for [RhL(2){eta(5)-(1-ferrocenyl)indenyl}] isomers. Crystallographic studies and DFT calculations provide a detailed description of the structural and electronic features of these complexes evidencing a significant difference in the extent of planarity of the flexible bridging ligand between the 1- and 2-ferrocenyl isomers. Independent experimental probes, in particular the potential splitting in the cyclic voltammograms and the IT bands in the near-IR spectra, are rationalised in the framework of Marcus-Hush theory and at quantum chemistry level by DFT and TD-DFT methods. These methods allow us to establish a trend based on the magnitude of iron-rhodium electronic coupling H(ab) ranging from valence trapped to almost delocalised ions. The quasi planar bridge and the olefin ancillary ligands make [Rh(nbd){eta(5)-(2-ferrocenyl)indenyl}](+) and [Rh(cod){eta(5)-(2-ferrocenyl)indenyl}](+) rare examples of heterobimetallic systems which can be classified as borderline Class II/Class III species.
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Affiliation(s)
- Saverio Santi
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, via Marzolo 1, 35131 Padua, Italy.
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16
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Locos OB, Arnold DP. The Heck reaction for porphyrin functionalisation: synthesis of meso-alkenyl monoporphyrins and palladium-catalysed formation of unprecedented meso–β ethene-linked diporphyrins. Org Biomol Chem 2006; 4:902-16. [PMID: 16493475 DOI: 10.1039/b516989e] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Palladium-catalysed coupling of the vinyl derivatives methyl acrylate, styrene and acrylonitrile with 5-bromo-10,15,20-triphenylporphyrin (MTriPPBr; M = 2H, Ni, Zn) and 5,15-dibromo-10,20-bis(3,5-di-tert-butylphenyl)porphyrin (MDAPBr(2)) produced a series of mono- and disubstituted alkenylporphyrins, thus demonstrating the applicability of meso-haloporphyrins in Heck-type reactions. The same technique was also applied to meso-ethenylporphyrins and simple aryl halides, with mixed results. Only meso-vinyl nickel(ii) porphyrins showed any reactivity under our conditions. A mixture of 1,1- and 1,2-disubstitution across the alkene was observed for 5-vinyl-10,15,20-triphenylporphyrinatonickel(ii) (meso-vinylNiTriPP), whereas 5-vinyl-10,20-bis(3,5-di-t-butylphenyl)porphyrinatonickel(ii) (meso-vinylNiDAP) produced a mixture of meso-1,1-, meso-1,2- and, surprisingly, beta-1,2-disubstituted Heck products. Coupling meso-vinylNiDAP with MTriPPBr under similar Heck conditions led unexpectedly to transbeta-meso-NiDAP-ethene-MTriPP dyads, affording the first members of a new class of alkenyl-linked diporphyrins. A mechanism for the unusual meso to beta rearrangement is discussed. The electronic absorption spectra of the dyads have a red-shifted shoulder on the Soret (B) band, which is evidence of a moderate degree of electronic interaction between the porphyrins via the ethenyl bridge.
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Affiliation(s)
- Oliver B Locos
- Synthesis and Molecular Recognition Program, School of Physical and Chemical Sciences, Queensland University of Technology, G.P.O. Box 2434, Brisbane 40001, Australia
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17
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Chen YJ, Chen SS, Lo SS, Huang TH, Wu CC, Lee GH, Peng SM, Yeh CY. Porphyrin dimers bridged by a platinum–diacetylide unit. Chem Commun (Camb) 2006:1015-7. [PMID: 16491194 DOI: 10.1039/b513921j] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of butadiyne- and platinum diacetylide-bridged conjugated porphyrin dimers have been prepared; electrochemical and UV-vis absorption measurements on these compounds show that the butadiyne-bridge confers stronger porphyrin-porphyrin conjugation than the platinum diacetylide-bridge.
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Affiliation(s)
- Yi-Jen Chen
- Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan
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18
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Huang TH, Chen YJ, Lo SS, Yen WN, Mai CL, Kuo MC, Yeh CY. Highly conjugated multiporphyrins: synthesis, spectroscopic and electrochemical properties. Dalton Trans 2006:2207-13. [PMID: 16673035 DOI: 10.1039/b516725f] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of meso-to-meso ethynyl-bridged multiporphyrin arrays have been synthesized using Sonogoshira palladium-catalyzed cross-coupling reactions involving the appropriate ethynylporphyrin and iodoporphyrin precursors. The absorption spectra of these multiporphyrins show splitting of the Soret bands and significant red shifts of the Q bands as compared to the combination of the corresponding components. These conjugated multiporphyrins also show red shifts in their emission spectra as the pi-conjugation is expanded. In the electrochemical measurements, the porphyrins dimer 7 shows two 1 - e- oxidations at E(1/2) = +0.63 and +0.76 V for the first electron abstraction from the two porphyrin rings, indicating electronic communication between the two porphyrin units. The porphyrin trimer 4 exhibits the first and second 1 - e- oxidations at E(1/2) = +0.68 and +0.77 V, respectively, which correspond to the two outer porphyrins. The cyclic voltammogram of pentamer 5 shows two overlapping 1 - e- couples at E(1/2) = +0.56 and +0.66 V, and one 2 - e- couple at E(1/2) = +0.86 V, for the four outer porphyrin units. These results demonstrate that in the porphyrin trimer and pentamer the individual peripheral porphyrin units are electrochemically coupled via a central porphyrin core. The UV-Vis-NIR spectra of the oxidized species of these multiporphyrins exhibit a broad intervalence charge transfer (IVCT) band in the region from 1200 to 3000 nm. The present work shows that a central porphyrin unit appended with ethynyl bridges affords strong electronic interactions between the peripheral porphyrin rings over a distance of about 15 A.
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Affiliation(s)
- Teng-Hui Huang
- Department of Chemistry, Center of Nanoscience and Nanotechnology, National Chung Hsing University, Taichung, Taiwan
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