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Yoshimura T, Nagata K, Nakano M. Octahedral Hexanuclear Rhenium Cluster Dimers Bridged by Pyrazine or 4,4'-Bipyridine with 23- and 24-Electron Configurations. Inorg Chem 2024; 63:14913-14923. [PMID: 39069964 DOI: 10.1021/acs.inorgchem.4c01321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
New pyrazine (pz)- and 4,4'-bipyridine (4,4'-bpy)-bridged octahedral hexanuclear rhenium(III) cluster dimers, [{Re6(μ3-S)8Cl5}2(μ-L)]6- (L = pz, [1]6-; L = 4,4'-bpy, [2]6-), with 2 × 24 d-electrons {Re6(24e)}2 were obtained in a single-step reaction via photoirradiation of [Re6(μ3-S)8Cl6]4- with L in a 2:1 ratio at room temperature. The {Re6(23e)}2 dimers, [{Re6(μ3-S)8Cl5}2(μ-L)]4- (L = pz, [1']4-; L = 4,4'-bpy, [2']4-), were synthesized through two-electron oxidation of [1]6- and [2]6-, respectively. The single-crystal X-ray structures of [1]6- and [1']4- were determined, revealing structural distortion of the Re6 core of [1']4- due to the Jahn-Teller effect. The cyclic voltammograms of [1]6- and [2]6- showed two steps of one-electron redox processes attributable to Re6(23e)Re6(24e)/{Re6(24e)}2 and {Re6(23e)}2/Re6(23e)Re6(24e), respectively. The separation between the two redox potentials is small (0.056 V for [1]6- and 0.039 V for [2]6-). The magnetic susceptibilities of [1']4- and [2']4- were almost temperature-independent, with values of 2.98 and 2.85 μB, respectively, indicating paramagnetism. These results suggest weak electronic interaction between two cluster units bridged by pz or 4,4'-bpy in the intercluster mixed valence state. The compounds [1]6- and [2]6- show photoluminescence in the near-infrared region at 296 K in the solid state.
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Affiliation(s)
- Takashi Yoshimura
- Radioisotope Research Center, Institute for Radiation Sciences, Osaka University, Suita 565-0871, Japan
| | - Kojiro Nagata
- Core Facility Center, Osaka University, Toyonaka 560-0043, Japan
| | - Motohiro Nakano
- Research Center for Thermal and Entropic Science, Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan
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Ryzhikov MR, Gayfulin YM, Ulantikov AA, Arentov DO, Kozlova SG, Mironov YV. Evolution of the Electronic Structure of the trans-[Re 6S 8bipy 4Cl 2] Octahedral Rhenium Cluster during Reduction. Molecules 2023; 28:molecules28093658. [PMID: 37175068 PMCID: PMC10180412 DOI: 10.3390/molecules28093658] [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: 03/30/2023] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
Understanding the processes that occur during the redox transformations of complexes coordinated by redox-active apical ligands is important for the design of electrochemically active compounds with functional properties. In this work, a detailed analysis of the interaction energy and electronic structure was performed for cluster complexes trans-[Re6S8bipy4Cl2]n (n = 2-, 4-, 6-, 8-), which can be obtained by stepwise electrochemical reduction of a neutral cluster trans-[Re6S8bipy4Cl2] in DMSO solution. It was shown that the formation of open-shell paramagnetic ions with S = 1, 2 and 1 is the most energetically favorable for n = 2-, 4- and 6-, respectively.
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Affiliation(s)
- Maxim R Ryzhikov
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia
| | - Yakov M Gayfulin
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia
| | - Anton A Ulantikov
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia
| | - Dmitry O Arentov
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia
| | - Svetlana G Kozlova
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia
| | - Yuri V Mironov
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia
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Octahedral Rhenium Cluster Complexes with 1,2-Bis(4-pyridyl)ethylene and 1,3-Bis(4-pyridyl)propane as Apical Ligands. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27227874. [PMID: 36431984 PMCID: PMC9699422 DOI: 10.3390/molecules27227874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/04/2022] [Accepted: 11/10/2022] [Indexed: 11/17/2022]
Abstract
A series of eight new octahedral rhenium cluster complexes with the general formula trans-[{Re6Q8}L4X2] (Q = S or Se; L = 1,2-Bis(4-pyridyl)ethylene (bpe) or 1,3-Bis(4-pyridyl)propane (bpp); X = Cl or Br) was synthesized and investigated. While bpe is a ligand with a conjugated aromatic system, bpp represents a molecule of opposite type and has independent aromatic systems of the two pyridine rings. It was shown that this difference in the electronic structure of the ligands has a fundamental effect on the electronic structure, electrochemical and luminescent properties of the corresponding cluster complexes. Specifically, the [{Re6Q8}(bpe)4X2] complexes in solutions show multiple quasi-reversible electrochemical transitions associated with reduction of the organic ligands. At the same time, the trans-[{Re6Q8}(bpp)4X2] complexes show multielectron quasi-irreversible reduction processes, which correlate with the mixed character of the lowest unoccupied molecular orbitals of these complexes. All the obtained new compounds exhibit red photoluminescence. The photophysical parameters (emission lifetimes and quantum yields) measured for the bpp complexes exceed those revealed for bpe complexes by more than an order of magnitude.
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Litvinova YM, Gayfulin YM, Sukhikh TS, Brylev KA, Mironov YV. Coordination Polymers Based on Rhenium Octahedral Chalcocyanide Cluster Anions and Ag + Cations with Bipyridine Analogs. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27227684. [PMID: 36431785 PMCID: PMC9698110 DOI: 10.3390/molecules27227684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/02/2022] [Accepted: 11/06/2022] [Indexed: 11/11/2022]
Abstract
A series of six coordination polymers based on octahedral cluster anions [Re6Q8(CN)6]4- (Q = S or Se) and Ag+ cations coordinated by bipyridine analogs were synthesized under solvothermal conditions. Their structures have been characterized by single crystal X-ray diffraction. Compounds 1 and 2 described by the general formula [{Ag(phen)}4Re6Q8(CN)6] (Q = Se (1), S (2); phen = 1,10-phenanthroline) exhibit layered structures assembled into a supramolecular network by CH…π contacts. At the same time, compounds [{Ag(bipym)}2Ag2Re6Se8(CN)6] (bipym = 2,2'-bipyrimidine) (3), [{Ag2(bipy)}Ag2Re6Se8(CN)6]·CH3CN (bipy = 4,4'-bipyridine) (4) and [{Ag(dpbp)}4Re6Q8(CN)6]·2H2O·2CH3CN (Q = Se (5), S (6); dpbp = 4,4'-Di(4-pyridyl)biphenyl)) evince framework structures. In 1, 2, 5 and 6 weak Ag⋯Ag interactions are observed. All the compounds show luminescence in the red region. The luminescence quantum yields and lifetimes were found to be notably higher than those for most of the coordination polymers based on the octahedral rhenium cluster complexes.
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Yoshimura T, Nishizawa H, Nagata K, Ito A, Sakuda E, Ishizaka S, Kitamura N, Shinohara A. Tuning the Ground- and Excited-State Redox Potentials of Octahedral Hexanuclear Rhenium(III) Complexes by the Combination of Terminal Halide and N-Heteroaromatic Ligands. ACS OMEGA 2022; 7:26965-26982. [PMID: 35936475 PMCID: PMC9352233 DOI: 10.1021/acsomega.2c03834] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 07/08/2022] [Indexed: 05/27/2023]
Abstract
The present study reports that the ground- and excited-state Re6(23e)/Re6(24e) redox potentials of an octahedral hexanuclear rhenium(III) complex can be controlled by systematically changing the number and type of the N-heteroaromatic ligand (L) and the number of chloride ions at the six terminal positions. Photoirradiation of [Re6(μ3-S)8Cl6]4- with an excess amount of L afforded a mono-L-substituted hexanuclear rhenium(III) complex, [Re6(μ3-S)8Cl5(L)]3- (L = 4-dimethylaminopyridine (dmap), 3,5-lutidine (lut), 4-methylpyridine (mpy), pyridine (py), 4,4'-bipyridine (bpy), 4-cyanopyridine (cpy), and pyrazine (pz)). The bis- and tris-lut-substituted complexes, trans- and cis-[Re6(μ3-S)8Cl4(lut)2]2- and mer-[Re6(μ3-S)8Cl3(lut)3]-, were synthesized by the reaction of [Re6(μ3-S)8Cl6]3- with an excess amount of lut in refluxed N,N-dimethylformamide. The mono-L-substituted complexes showed one-electron redox processes assignable to E 1/2[Re6(23e)/Re6(24e)] = 0.49-0.58 V versus Ag/AgCl. The ground-state oxidation potentials were linearly correlated with the pK a of the N-heteroaromatic ligand [pK a(L)], the 1H NMR chemical shift of the ortho proton on the coordinating ligand, and the Hammett constant (σ) of the pyridyl-ligand substituent. The series of [Re6(μ3-S)8X6-n (L) n ] n-4 complexes (n = 0, X = Cl, Br, I, or NCS; n = 1-3, X = Cl) showed a linear correlation with the sum of the Lever electrochemical parameters at the six terminal ligands (ΣE L). The cyclic voltammograms of the mono-L-substituted complexes (L = bpy, cpy, and pz) showed one-electron redox waves assignable to E 1/2(L0/L-) = -1.28 to -1.48 V versus Ag/AgCl. Two types of photoluminescences were observed for the complexes, originating from the cluster core-centered excited triplet state (3CC) for L = dmap, lut, mpy, and py and from the metal-to-ligand charge-transfer excited triplet state (3MLCT) for L = bpy, cpy, and pz. The complexes with the 3CC character exhibited emission features and photophysical properties similar to those of ordinary hexanuclear rhenium complexes. The emission maximum wavelength of the complexes with 3MLCT shifted to the longer wavelength in the order L = 4-phenylpyridine (ppy), bpy, pz, and cpy, which agreed with the difference between E 1/2[Re6(23e)/Re6(24e)] and E 1/2(L0/L-). The calculated oxidation potential of the excited hexanuclear rhenium complex with the 3CC character was linearly correlated with pK a(L), σ, and ΣE L. The ground- and excited-state oxidation potentials were finely tuned by the combination of halide and L ligands at the terminal positions.
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Affiliation(s)
- Takashi Yoshimura
- Radioisotope
Research Center, Institute for Radiation Sciences, Osaka University, Suita 565-0871, Japan
| | - Hayato Nishizawa
- Department
of Chemistry, Graduate School of Science, Osaka University, Toyonaka 560-0043, Japan
| | - Kojiro Nagata
- Radioisotope
Research Center, Institute for Radiation Sciences, Osaka University, Suita 565-0871, Japan
| | - Akitaka Ito
- School
of Environmental Science and Engineering, Kochi University of Technology, Kochi 782-8502, Japan
| | - Eri Sakuda
- Division
of Chemistry and Materials Science, Graduate School of Engineering, Nagasaki University, Nagasaki 852-8521, Japan
| | - Shoji Ishizaka
- Graduate
School of Advanced Science and Engineering, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Noboru Kitamura
- Department
of Chemistry, Faculty of Science, Hokkaido
University, Sapporo 060-0810, Japan
- Toyota
Physical and Chemical Research Institute, Nagakute 480-1192, Aichi, Japan
| | - Atsushi Shinohara
- Radioisotope
Research Center, Institute for Radiation Sciences, Osaka University, Suita 565-0871, Japan
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Thermally Controlled Synthesis of Octahedral Rhenium Clusters with 4,4′-Bipyridine and CN− Apical Ligands. Symmetry (Basel) 2021. [DOI: 10.3390/sym13112187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The selective preparation, structural and spectroscopic study of two new rhenium cluster complexes trans-[Re6S8(bpy)4(CN)2] and trans-[Re6S8(bpy)2(CN)4]2− (bpy = 4,4′-bipyridine) obtained by reactions of corresponding hexarhenium cyanohalides with molten bpy are reported. The complexes were crystallized as solvates, displaying supramolecular structures based on cluster units linked by numerous weak interactions with bpy molecules. The molecular compound trans-[Re6S8(bpy)4(CN)2] (1) is insoluble in water and common organic solvents, while the ionic compound trans-Cs1.7K0.3[Re6S8(bpy)2(CN)4] (2) is somewhat soluble in DMSO, DMF and N-methylpyrrolidone. The presence of the redox-active ligand bpy leads to the occurrence of multi-electron reduction transitions in a solution of 2 at moderate potential values. The ambidentate CN− ligand is the secondary functional group, which has potential for the synthesis of coordination polymers based on the new cluster complexes. In addition, both new compounds show a weak red luminescence, which is characteristic of complexes with a {Re6S8}2+ cluster core.
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