1
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Leong DW, Shao Y, Ni Z, Bhuvanesh N, Ozerov OV. A bis(PCN) palladium pincer complex with a remarkably planar 2,5-diarylpyrazine core. Dalton Trans 2024; 53:6520-6523. [PMID: 38563468 DOI: 10.1039/d3dt04248k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
A bimetallic Pd complex of a bis(pincer) with a diarylpyrazine core has been prepared. The complex demonstrates near-perfect coplanarity of the aromatic core, is fluorescent under UV irradiation, and displays two quasi-reversible reduction events.
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Affiliation(s)
- Derek W Leong
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA.
| | - Yanwu Shao
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA.
| | - Zhen Ni
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA.
| | - Nattamai Bhuvanesh
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA.
| | - Oleg V Ozerov
- Department of Chemistry, Texas A&M University, College Station, TX 77842, USA.
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2
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Bera SK, Lahiri GK. Unprecedented metal-metal bonded {Ru 4(μ 3-O) 2} butterfly core in oxido-carboxylato bridged mixed valence cluster-structural elucidation and electronic forms in accessible redox states. Dalton Trans 2020; 49:13573-13581. [PMID: 32970073 DOI: 10.1039/d0dt02741c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unprecedented metal-metal bonded oxido-carboxylato bridged mixed valence tetraruthenium cluster [(acac)6Ru(μ3-O)2(μ-CH3COO)3] 1 (S = 1/2) (acac = acetylacetonate) with {Ru4(μ3-O)2} "butterfly" core has been achieved via the reaction of Ru(acac)2(CH3CN)2 with excess CH3COONa (Ru : CH3COONa = 1 : 15) in refluxing EtOH-H2O (5 : 1). Structural analysis of 1 ascertained a unique Ru-Ru bonded (Ru2-Ru3: 2.5187(6) Å (DFT: 2.560 Å)) {Ru2(Ru-Ru)(μ3-O)2} butterfly core, unlike the reported other Fe4 or Mn4 derived "butterfly" core. The connectivity of Ru4(μ3-O)2 core in 1 with three Ru2(μ-CH3COO)3 and two each Ru-(acac)2/Ru-acac units resulted in interconnected four RuO6 octahedral entities. The doubly bridged μ3-O2- ions of the nearly planar central metal-metal bonded Ru2O2 core (Ru2-Ru3, "body" or "hinge") linked to the remaining two "wing-tip" Ru atoms (Ru1 and Ru4). Complex 1 with a S = 1/2 spin state displayed paramagnetically shifted 1H NMR over a wide chemical shift range in CDCl3 (δ, 13 to -30 ppm) and a metal based anisotropic EPR (g1 = 2.17, g2 = 2.01, g3 = 1.86; Δg = g1-g3 = 0.31 and 〈g〉 = [1/3(g12 + g22 + g32]1/2 = 2.01) at 100 K in CH3CN-toluene. The metal based one-electron reversible oxidation at 0.49 V and reduction at 0.485 V versus SCE of 1 led to the EPR inactive (even at 4 K) spin-coupled RuIIIRuIIIRuIVRuIV (S = 0) and RuIIIRuIIIRuIIIRuIII (S = 0) electronic configurations for 1+ and 1-, respectively. Mixed valence 1 and 1+ exhibited low-energy near-infrared (NIR) absorption bands at 1350 nm and 1156 nm, respectively, in CH3CN. A combined experimental (UV-vis-NIR and EPR spectroelectrochemistry) and theoretical (DFT) analysis indicated a delocalised mixed valence form of 1 ({Ru2(Ru-Ru)(μ3-O)2}).
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Affiliation(s)
- Sudip Kumar Bera
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
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3
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Tripathy SK, van der Meer M, Sahoo A, Laha P, Dehury N, Plebst S, Sarkar B, Samanta K, Patra S. A dinuclear [{(p-cym)Ru(II)Cl}2(μ-bpytz˙(-))](+) complex bridged by a radical anion: synthesis, spectroelectrochemical, EPR and theoretical investigation (bpytz = 3,6-bis(3,5-dimethylpyrazolyl)1,2,4,5-tetrazine; p-cym = p-cymene). Dalton Trans 2018; 45:12532-8. [PMID: 27435992 DOI: 10.1039/c6dt01995a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The reaction of the chloro-bridged dimeric precursor [{(p-cym)Ru(II)Cl}(μ-Cl)]2 (p-cym = p-cymene) with the bridging ligand 3,6-bis(3,5-dimethylpyrazolyl)-1,2,4,5-tetrazine (bpytz) in ethanol results in the formation of the dinuclear complex [{(p-cym)Ru(II)Cl}2(μ-bpytz˙(-))](+), [1](+). The bridging tetrazine ligand is reduced to the anion radical (bpytz˙(-)) which connects the two Ru(II) centres. Compound [1](PF6) has been characterised by an array of spectroscopic and electrochemical techniques. The radical anion character has been confirmed by magnetic moment (corresponding to one electron paramagnetism) measurement, EPR spectroscopic investigation (tetrazine radical anion based EPR spectrum) as well as density functional theory based calculations. Complex [1](+) displays two successive one electron oxidation processes at 0.66 and 1.56 V versus Ag/AgCl which can be attributed to [{(p-cym)Ru(II)C}2(μ-bpytz˙(-))](+)/[{(p-cym)Ru(II)Cl}2(μ-bpytz)](2+) and [{(p-cym)Ru(II)Cl}2(μ-bpytz)](+)/[{(p-cym)Ru(III)Cl}2(μ-bpytz)](2+) processes (couples I and II), respectively. The reduction processes (couple III-couple V), which are irreversible, likely involve the successive reduction of the bridging ligand and the metal centres together with loss of the coordinated chloride ligands. UV-Vis-NIR spectroelectrochemical investigation reveals typical tetrazine radical anion containing bands for [1](+) and a strong absorption in the visible region for the oxidized form [1](2+), which can be assigned to a Ru(II) → π* (tetrazine) MLCT transition. The assignment of spectroscopic bands was confirmed by theoretical calculations.
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Affiliation(s)
- Suman Kumar Tripathy
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar - 751007, India.
| | - Margarethe van der Meer
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, D-14195 Berlin, Germany.
| | - Anupam Sahoo
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar - 751007, India.
| | - Paltan Laha
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar - 751007, India.
| | - Niranjan Dehury
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar - 751007, India.
| | - Sebastian Plebst
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569, Stuttgart, Germany
| | - Biprajit Sarkar
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, D-14195 Berlin, Germany.
| | - Kousik Samanta
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar - 751007, India.
| | - Srikanta Patra
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar - 751007, India.
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4
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Khan FF, Mandal A, Klein J, Priego JL, Jiménez-Aparicio R, Sarkar B, Lahiri GK. Mixed Donor-Acceptor-Derived N
,N′
-Diarylpyrazine-2,5-dicarboxamido-Bridged Diruthenium Systems: Structures, Magnetic Properties, and Electronic Forms in Multiredox States. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201701009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Farheen Fatima Khan
- Department of Chemistry; Indian Institute of Technology Bombay; 400076 Powai, Mumbai India
| | - Abhishek Mandal
- Department of Chemistry; Indian Institute of Technology Bombay; 400076 Powai, Mumbai India
| | - Johannes Klein
- Institut für Chemie und Biochemie; Anorganische Chemie; Freie Universitaet Berlin; Fabeckstraße 34-36 14195 Berlin Germany
| | - José Luis Priego
- Departamento de Química Inorgánica; Facultad de Ciencias Químicas; Universidad Complutense; 28040 Madrid Spain
| | - Reyes Jiménez-Aparicio
- Departamento de Química Inorgánica; Facultad de Ciencias Químicas; Universidad Complutense; 28040 Madrid Spain
| | - Biprajit Sarkar
- Institut für Chemie und Biochemie; Anorganische Chemie; Freie Universitaet Berlin; Fabeckstraße 34-36 14195 Berlin Germany
| | - Goutam Kumar Lahiri
- Department of Chemistry; Indian Institute of Technology Bombay; 400076 Powai, Mumbai India
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5
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Cepeda J, Beobide G, Castillo O, Luque A, Pérez-Yáñez S. Structural diversity of coordination compounds derived from double-chelating and planar diazinedicarboxylate ligands. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.08.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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6
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Singha Hazari A, Mandal A, Beyer K, Paretzki A, Kaim W, Lahiri GK. Metal–Metal Bridging Using the DPPP Dye System: Electronic Configurations within Multiple Redox Series. Inorg Chem 2017; 56:2992-3004. [DOI: 10.1021/acs.inorgchem.6b03112] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Arijit Singha Hazari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Abhishek Mandal
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Katharina Beyer
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Alexa Paretzki
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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7
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Mandal A, Hoque MA, Grupp A, Paretzki A, Kaim W, Lahiri GK. Analysis of Redox Series of Unsymmetrical 1,4-Diamido-9,10-anthraquinone-Bridged Diruthenium Compounds. Inorg Chem 2016; 55:2146-56. [DOI: 10.1021/acs.inorgchem.5b02541] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Abhishek Mandal
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai−400076, India
| | - Md Asmaul Hoque
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai−400076, India
| | - Anita Grupp
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Alexa Paretzki
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai−400076, India
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8
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Das A, Ghosh P, Plebst S, Schwederski B, Mobin SM, Kaim W, Lahiri GK. Ancillary Ligand Control of Electronic Structure in o-Benzoquinonediimine-Ruthenium Complex Redox Series: Structures, Electron Paramagnetic Resonance (EPR), and Ultraviolet−Visible−Near-Infrared (UV-vis-NIR) Spectroelectrochemistry. Inorg Chem 2015; 54:3376-86. [DOI: 10.1021/ic503070j] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ankita Das
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Prabir Ghosh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Sebastian Plebst
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Brigitte Schwederski
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Shaikh M. Mobin
- Discipline of Chemistry,
School of Basic Sciences, Indian Institute of Technology Indore, Indore 452017, India
| | - Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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9
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Das A, Mobin SM, Lahiri GK. Recognition of fractional non-innocent feature of osmium coordinated 2,2′-biimidazole or 2,2′-bis(4,5-dimethylimidazole) and their interactions with anions. Dalton Trans 2015; 44:13204-19. [DOI: 10.1039/c5dt01763g] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The non-innocent feature of osmium coordinated doubly deprotonated 2,2′-biimidazole derivatives in symmetric dimeric complexes leads to a mixed electronic structural configuration.
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Affiliation(s)
- Ankita Das
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai 400076
- India
| | - Shaikh M. Mobin
- Discipline of Chemistry
- School of Basic Sciences
- Indian Institute of Technology Indore
- Indore 452017
- India
| | - Goutam Kumar Lahiri
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai 400076
- India
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10
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Ghosh P, Mondal P, Ray R, Das A, Bag S, Mobin SM, Lahiri GK. Significant Influence of Coligands Toward Varying Coordination Modes of 2,2′-Bipyridine-3,3′-diol in Ruthenium Complexes. Inorg Chem 2014; 53:6094-106. [DOI: 10.1021/ic5004676] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Prabir Ghosh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Prasenjit Mondal
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Ritwika Ray
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Ankita Das
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Sukdev Bag
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Shaikh M. Mobin
- Discipline of Chemistry, School of Basic Sciences, Indian Institute of Technology Indore, Indore 452017, India
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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11
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Das A, Agarwala H, Kundu T, Ghosh P, Mondal S, Mobin SM, Lahiri GK. Electronic structures and selective fluoride sensing features of Os(bpy)2(HL2−) and [{Os(bpy)2}2(μ-HL2−)]2+ (H3L: 5-(1H-benzo[d]imidazol-2-yl)-1H-imidazole-4-carboxylic acid). Dalton Trans 2014; 43:13932-47. [DOI: 10.1039/c4dt01821d] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The non-innocence of coordinated HL2− in [(bpy)2Os(HL2−)]n (1n) and (2n) and their selectivity towards F− recognition were evaluated.
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Affiliation(s)
- Ankita Das
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai-400076, India
| | - Hemlata Agarwala
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai-400076, India
| | - Tanaya Kundu
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai-400076, India
| | - Prabir Ghosh
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai-400076, India
| | - Sudipta Mondal
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai-400076, India
| | - Shaikh M. Mobin
- Discipline of Chemistry
- School of Basic Sciences
- Indian Institute of Technology Indore
- Indore 452017, India
| | - Goutam Kumar Lahiri
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai-400076, India
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12
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Kundu T, Schweinfurth D, Sarkar B, Mondal TK, Fiedler J, Mobin SM, Puranik VG, Kaim W, Lahiri GK. Strong metal-metal coupling in mixed-valent intermediates [Cl(L)Ru(μ-tppz)Ru(L)Cl]+, L = β-diketonato ligands, tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine. Dalton Trans 2013; 41:13429-40. [PMID: 23007666 DOI: 10.1039/c2dt31763j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Five diruthenium(II) complexes [Cl(L)Ru(μ-tppz)Ru(L)Cl] (1-5) containing differently substituted β-diketonato derivatives (1: L = 2,4-pentanedionato; 2: L = 3,5-heptanedionato; 3: L = 2,2,6,6-tetramethyl-3,5-heptanedionato; 4: L = 3-methyl-2,4-pentanedionato; 5: L = 3-ethyl-2,4-pentanedionato) as ancillary ligands (L) were synthesized and studied by spectroelectrochemistry (UV-Vis-NIR, electron paramagnetic resonance (EPR)). X-ray structural characterisation revealed anti (1, 2, 5) or syn (3) configuration as well as non-planarity of the bis-tridentate tppz bridge and strong dπ(Ru(II)) → π*(pyrazine, tppz) back-bonding. The widely separated one-electron oxidation steps, Ru(II)Ru(II)/Ru(II)Ru(III) and Ru(II)Ru(III)/Ru(III)Ru(III), result in large comproportionation constants (K(c)) of ≥10(10) for the mixed-valent intermediates. The syn-configurated (n) exhibits a particularly high K(c) of 10(12) for n = 1+, accompanied by density functional theory (DFT)-calculated minimum Ru-N bond lengths for this Ru(II)Ru(III) intermediate. The electrogenerated mixed-valent states 1(+)-5(+) exhibit anisotropic EPR spectra at 110 K with average values <g> of 2.304-2.234 and g anisotropies Δg = g(1)-g(3) of 0.82-0.99. Metal-to-metal charge transfer (MMCT) absorptions occur for 1(+)-5(+) in the NIR region at 1660 nm-1750 nm (ε ≈ 2700 dm(3) mol(-1) cm(-1), Δν(1/2) ≈ 1800 cm(-1)). DFT calculations of 1(+) and 3(+) yield comparable Mulliken spin densities of about 0.60 for the metal ions, corresponding to valence-delocalised situations (Ru(2.5))(2). Rather large spin densities of about -0.4 were calculated for the tppz bridges in 1(+) and 3(+). The calculated electronic interaction values (V(AB)) for 1(+)-5(+) are about 3000 cm(-1), comparable to that for the Creutz-Taube ion at 3185 cm(-1). The DFT calculations predict that the Ru(III)Ru(III) forms in 1(2+)-5(2+) prefer a triplet (S = 1) ground state with ΔE (S = 0 - S = 1) ∼5000 cm(-1). One-electron reduction takes place at the tppz bridge which results in species [Cl(L)Ru(II)(μ-tppz˙(-))Ru(II)(L)Cl](-) (1˙(-)-3˙(-), 5˙(-)) which exhibit free radical-type EPR signals and NIR transitions typical of the tppz radical anion. The system 4(n) is distinguished by lability of the Ru-Cl bonds.
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Affiliation(s)
- Tanaya Kundu
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
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13
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Mondal P, Ehret F, Bubrin M, Das A, Mobin SM, Kaim W, Lahiri GK. A Diruthenium Complex of a “Nindigo” Ligand. Inorg Chem 2013; 52:8467-75. [DOI: 10.1021/ic400390b] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Prasenjit Mondal
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai
400076, India
| | - Fabian Ehret
- Institut
für Anorganische
Chemie, Universität Stuttgart, Pfaffenwaldring
55, D-70550 Stuttgart, Germany
| | - Martina Bubrin
- Institut
für Anorganische
Chemie, Universität Stuttgart, Pfaffenwaldring
55, D-70550 Stuttgart, Germany
| | - Amit Das
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai
400076, India
| | - Shaikh M. Mobin
- Discipline of Chemistry, School
of Basic Sciences, Indian Institute of Technology Indore, Indore 452017, India
| | - Wolfgang Kaim
- Institut
für Anorganische
Chemie, Universität Stuttgart, Pfaffenwaldring
55, D-70550 Stuttgart, Germany
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai
400076, India
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14
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McKinnon SDJ, Patrick BO, Lever ABP, Hicks RG. Binuclear ruthenium complexes of a neutral radical bridging ligand. A new "spin" on mixed valency. Inorg Chem 2013; 52:8053-66. [PMID: 23789578 DOI: 10.1021/ic400704j] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The electronic structures of (LX)2Ru(Vd)Ru(LX)2 complexes (Vd = 1,5-diisopropyl-3-(4,6-dimethyl-2-pyrimidinyl)-6-oxoverdazyl radical; LX = acac (acetylacetonate) or hfac (hexafluoroacetylacetonate)) in multiple charge states have been investigated experimentally and computationally. The main focus was to probe the consequences of the interplay between the ruthenium ions and the redox-active verdazyl ligand for possible mixed-valent behavior. Cyclic voltammetry studies reveal one reversible reduction and one reversible oxidation process for both complexes; in addition the acac-based derivative possesses a second reversible oxidation. Analysis of a collection of experimental (X-ray structures, EPR, electronic spectra) and computational (TD-DFT (PCM)) data reveal that the ruthenium ancillary ligands (acac vs hfac) have dramatic consequences for the electronic structures of the complexes in all charge states studied. In the hfac series, the neutral complex is best regarded as a binuclear Ru(II) species bridged by a neutral radical ligand. Reduction to give the anionic complex takes place on the verdazyl ligand, whereas oxidation to the cation (a closed shell species) is shared between Vd and ruthenium. For the acac-based complexes, the neutral species is most accurately represented as a Ru(II)/Ru(III) mixed valent complex containing a bridging verdazyl anion, though some bis(Ru(II))-neutral radical character remains. The monocation complex contains a significant contribution from a "broken symmetry" singlet diradical structure, best represented as a bis-Ru(III) system with an anionic ligand, with significant spin coupling of the two Ru(III) centers via the Vd(-1) ligand (calculated J = -218 cm(-1)). The dication, a spin doublet, consists of two Ru(III) ions linked (and antiferromagnetically coupled) to the neutral radical ligand. Computed net σ- and π-back-donation, spin densities, and orbital populations are provided. Time dependent DFT is used to predict the optical spectra and assign experimental data.
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Affiliation(s)
- Stephen D J McKinnon
- Department of Chemistry, University of Victoria, P.O. Box 3065 STN CSC, Victoria, B.C. V8W 3 V6, Canada
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15
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Das A, Kundu T, Mobin SM, Priego JL, Jiménez-Aparicio R, Lahiri GK. Influence of ancillary ligands on the electronic structure and anion sensing features of ligand bridged diruthenium complexes. Dalton Trans 2013; 42:13733-46. [DOI: 10.1039/c3dt50853f] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Das A, Scherer TM, Mondal P, Mobin SM, Kaim W, Lahiri GK. Experimental and DFT evidence for the fractional non-innocence of a β-diketonate ligand. Chemistry 2012; 18:14434-43. [PMID: 23001725 DOI: 10.1002/chem.201201785] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Indexed: 11/05/2022]
Abstract
New compounds [Ru(pap)(2)(L)](ClO(4)), [Ru(pap)(L)(2)], and [Ru(acac)(2)(L)] (pap = 2-phenylazopyridine, L(-) = 9-oxidophenalenone, acac(-) = 2,4-pentanedionate) have been prepared and studied regarding their electron-transfer behavior, both experimentally and by using DFT calculations. [Ru(pap)(2)(L)](ClO(4)) and [Ru(acac)(2)(L)] were characterized by crystal-structure analysis. Spectroelectrochemistry (EPR, UV/Vis/NIR), in conjunction with cyclic voltammetry, showed a wide range of about 2 V for the potential of the Ru(III/II) couple, which was in agreement with the very different characteristics of the strongly π-accepting pap ligand and the σ-donating acac(-) ligand. At the rather high potential of +1.35 V versus SCE, the oxidation of L(-) into L(⋅) could be deduced from the near-IR absorption of [Ru(III)(pap)(L(⋅))(L(-))](2+). Other intense long-wavelength transitions, including LMCT (L(-) → Ru(III)) and LL/CT (pap(⋅-) → L(-)) processes, were confirmed by TD-DFT results. DFT calculations and EPR data for the paramagnetic intermediates allowed us to assess the spin densities, which revealed two cases with considerable contributions from L-radical-involving forms, that is, [Ru(III)(pap(0))(2)(L(-))](2+) ↔ [Ru(II)(pap(0))(2)(L(⋅))](2+) and [Ru(III)(pap(0))(L(-))(2)](+) ↔ [Ru(II)(pap(0))(L(⋅))(L(-))](+). Calculations of electrogenerated complex [Ru(II)(pap(⋅-))(pap(0))(L(-))] displayed considerable negative spin density (-0.188) at the bridging metal.
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Affiliation(s)
- Amit Das
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India)
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Kämper S, Paretzki A, Fiedler J, Záliš S, Kaim W. Solar Cell Sensitizer Models [Ru(bpy-R)2(NCS)2] Probed by Spectroelectrochemistry. Inorg Chem 2012; 51:2097-104. [DOI: 10.1021/ic201825h] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sara Kämper
- Institut für
Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Alexa Paretzki
- Institut für
Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Jan Fiedler
- J. Heyrovský Institute
of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-18223 Prague,
Czech Republic
| | - Stanislav Záliš
- J. Heyrovský Institute
of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-18223 Prague,
Czech Republic
| | - Wolfgang Kaim
- Institut für
Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
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Fox MA, Le Guennic B, Roberts RL, Brue DA, Yufit DS, Howard JAK, Manca G, Halet JF, Hartl F, Low PJ. Simultaneous Bridge-Localized and Mixed-Valence Character in Diruthenium Radical Cations Featuring Diethynylaromatic Bridging Ligands. J Am Chem Soc 2011; 133:18433-46. [DOI: 10.1021/ja207827m] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Mark A. Fox
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
| | - Boris Le Guennic
- Laboratoire des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, 35042 Rennes cedex, France
- Université de Lyon, CNRS, Institut de Chimie de Lyon, Ecole Normale Supérieure de Lyon, 15 parvis René Descartes, BP7000, 69342 Lyon Cedex 07, France
| | - Rachel L. Roberts
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
| | - Daniel A. Brue
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
| | - Dmitry S. Yufit
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
| | | | - Gabriele Manca
- Laboratoire des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, 35042 Rennes cedex, France
- Istituto di Chimica dei Composti Organometallici, ICCOM-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence, Italy
| | - Jean-François Halet
- Laboratoire des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, 35042 Rennes cedex, France
| | - František Hartl
- Department of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, U.K
| | - Paul J. Low
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
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Das A, Scherer T, Maji S, Mondal TK, Mobin SM, Urbanos FA, Jiménez-Aparicio R, Kaim W, Lahiri GK. Reductive Approach to Mixed Valency (n= 1−) in the Pyrazine Ligand-Bridged [(acac)2Ru(μ-L2–)Ru(acac)2]n(L2–= 2,5-Pyrazine-dicarboxylate) through Experiment and Theory. Inorg Chem 2011; 50:7040-9. [DOI: 10.1021/ic200530u] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Preparation and electrochemical properties of novel cyclic dinuclear acetylacetonato ruthenium complexes doubly bridged with sulfur and/or disulfur. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Nawn G, Waldie KM, Oakley SR, Peters BD, Mandel D, Patrick BO, McDonald R, Hicks RG. Redox-active bridging ligands based on indigo diimine ("Nindigo") derivatives. Inorg Chem 2011; 50:9826-37. [PMID: 21688798 DOI: 10.1021/ic200388y] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Reactions of indigo with a variety of substituted anilines produce the corresponding indigo diimines ("Nindigos") in good yields. Nindigo coordination complexes are subsequently prepared by reactions of the Nindigo ligands with Pd(hfac)(2). In most cases, binuclear complexes are obtained in which the deprotonated Nindigo bridges two Pd(hfac) moieties in the expected bis-bidentate binding mode. When the Nindigo possesses bulky substituents on the imine (mesityl, 2,6-dimethylphenyl, 2,6-diisopropylphenyl, etc.), mononuclear Pf(hfac) complexes are obtained in which the Nindigo core has isomerized from a trans- to a cis-alkene; in these structures, the palladium is bound to the cis-Nindigo ligand at the two indole nitrogen atoms; the remaining proton is bound between the imine nitrogen atoms. The palladium complexes possess intense electronic absorption bands [near 920 nm for the binuclear complexes and 820 nm for the mononuclear cis-Nindigo complexes; extinction coefficients are (1.0-2.0) × 10(4) M(-1) cm(-1)] that are ligand-centered (π-π*) transitions. Cyclic voltammetry investigations reveal multiple redox events that are also ligand-centered in origin. All of the palladium complexes can be reversibly oxidized in two sequential one-electron steps; the binuclear complexes are reduced in a two-electron process whose reversibility depends on the Nindigo ligand substituent; the mononuclear palladium species show two one-electron reductions, only the first of which is quasi-reversible.
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Affiliation(s)
- Graeme Nawn
- Department of Chemistry, University of Victoria, P.O. Box 3065 STN CSC, Victoria, British Columbia V8W 3V6, Canada
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Das D, Mondal TK, Chowdhury AD, Weisser F, Schweinfurth D, Sarkar B, Mobin SM, Urbanos FA, Jiménez-Aparicio R, Lahiri GK. Valence and spin situations in isomeric [(bpy)Ru(Q′)2]n (Q′ = 3,5-di-tert-butyl-N-aryl-1,2-benzoquinonemonoimine). An experimental and DFT analysis. Dalton Trans 2011; 40:8377-90. [DOI: 10.1039/c1dt10609k] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kundu T, Sarkar B, Mondal TK, Fiedler J, Mobin SM, Kaim W, Lahiri GK. Carboxylate Tolerance of the Redox-Active Platform [Ru(μ-tppz)Ru]n, where tppz = 2,3,5,6-Tetrakis(2-pyridyl)pyrazine, in the Electron-Transfer Series [(L)ClRu(μ-tppz)RuCl(L)]n, n = 2+, +, 0, −, 2−, with 2-Picolinato, Quinaldato, and 8-Quinolinecarboxylato Ligands (L−). Inorg Chem 2010; 49:6565-74. [DOI: 10.1021/ic100500p] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Tanaya Kundu
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Biprajit Sarkar
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Tapan Kumar Mondal
- Department of Chemistry, Jadavpur University, Jadavpur, Kolkata 700032, India
| | - Jan Fiedler
- J. Heyrovský Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, CZ-18223 Prague, Czech Republic
| | - Shaikh M. Mobin
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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Kundu T, Mobin SM, Lahiri GK. Paramagnetic ruthenium-biimidazole derivatives [(acac)2RuIII(LHn)]m, n/m = 2/+, 1/0, 0/−. Synthesis, structures, solution properties and anion receptor features in solution state. Dalton Trans 2010; 39:4232-42. [DOI: 10.1039/b919036h] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Pratihar JL, Bhaduri S, Pattanayak P, Patra D, Chattopadhyay S. Reactions of 2-(arylazo)aniline with ruthenium substrates: Isolation, characterizations and reactivities of delocalized diazoketiminato and orthometallated Ru(II) chelates. J Organomet Chem 2009. [DOI: 10.1016/j.jorganchem.2009.06.038] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Das D, Mondal TK, Mobin SM, Lahiri GK. Sensitive Valence Structures of [(pap)2Ru(Q)]n (n = +2, +1, 0, −1, −2) with Two Different Redox Noninnocent Ligands, Q = 3,5-Di-tert-butyl-N-aryl-1,2-benzoquinonemonoimine and pap = 2-Phenylazopyridine. Inorg Chem 2009; 48:9800-10. [DOI: 10.1021/ic901343j] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dipanwita Das
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India
| | - Tapan Kumar Mondal
- Department of Chemistry, Jadavpur University, Jadavpur, Kolkata-700032, India
| | - Shaikh M. Mobin
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India
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Kumbhakar D, Sarkar B, Das A, Das AK, Mobin SM, Fiedler J, Kaim W, Lahiri GK. Valence structures of the diastereomeric complexes meso- and rac-[Ru2(acac)4(μ-Q)]n (n = 2−, 1−, 0, 1+, 2+) with the multiple quinonoid bridging ligand Q = 1,2,4,5-tetraimino-3,6-diketocyclohexane. Dalton Trans 2009:9645-52. [DOI: 10.1039/b906900c] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Cheung WM, Ng HY, Williams ID, Leung WH. Ruthenium Complexes with Tetraphenylimidodiphosphinate: Syntheses, Structures, and Applications to Catalytic Organic Oxidation. Inorg Chem 2008; 47:4383-91. [DOI: 10.1021/ic800018d] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wai-Man Cheung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Peopleʼs Republic of China
| | - Ho-Yuen Ng
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Peopleʼs Republic of China
| | - Ian D. Williams
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Peopleʼs Republic of China
| | - Wa-Hung Leung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Peopleʼs Republic of China
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