Ruthenium Derivatives of in Situ Generated Redox-Active 1,2-Dinitrosobenzene and 2-Nitrosoanilido. Diverse Structural and Electronic Forms
| Autor: | Goutam Kumar Lahiri, Soumyodip Banerjee, Prabir Ghosh |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
In situ
Deprotonated 2 2'-Bipyridine-3 3'-Diol Transition-Metal-Complexes Stereochemistry chemistry.chemical_element Varying Coordination Modes Non-Innocent Ligands 010402 general chemistry 01 natural sciences Inorganic Chemistry Metal chemistry.chemical_compound Density-Functional Theory Pyridine Redox active Physical and Theoretical Chemistry Bridged Diruthenium Complexes Boron Difluoride Complexes Nitrosoarene Ligands 010405 organic chemistry Nitroso Tautomer 0104 chemical sciences Ruthenium O-Benzoquinonediimine chemistry visual_art visual_art.visual_art_medium Oxidation-State Combinations |
| Zdroj: | Inorganic Chemistry. 55:12832-12843 |
| ISSN: | 1520-510X 0020-1669 |
| DOI: | 10.1021/acs.inorgchem.6b02197 |
| Popis: | The article describes one-pot synthesis and structural elucidation of tc-[Ru-II(pap)(2)(L)]ClO4 [1]ClO4 and tc-[Ru-II(pap)(2)(L'(-))]ClO4 [2]ClO4, which were obtained from tc-[Ru-II(pap)(2)(EtOH)2](ClO4)(2) and benzofuroxan (L = 1,2-dinitrosobenzene, an intermediate tautomeric form of the biologically active benzofuroxan, L'(-) = 2-nitrosoanilido, pap = 2-phenylazopyridine, tc = trans and cis corresponding to pyridine and azo nitrogen donors of pap, respectively). The same reaction with the newly synthesized and structurally characterized metal precursor cc-Ru-II(2,6-dichloropap)(2)Cl-2, however, affords isomeric ct-[Ru-II(2,6-dichloropap)2(L-)](+) (3a+()) and tc-[RuII(2,6-dichloropap)(2)(L-)](+) (3b(+)) (cc, ct, and tc with respect to pyridine and azo nitrogens of 2,6-dichloropap) with the structural authentication of elusive ct-isomeric form of {Ru(pap)(2)} family. The impact of trans or cis orientation of the nitroso group of L/L' with respect to the N=N (azo) function of pap in the complexes was reflected in the relative lengthening or shortening of the latter distance, respectively. The redox-sensitive bond parameters of 1(+) and 3(+) reveal the intermediate radical form of L-, while 2(+) involves in situ generated L'(-). The multiple redox processes of the complexes in CH3CN are analyzed via experimental and density functional theory (DFT) and time-dependent DFT calculations. One-electron oxidation of the electron paramagnetic resonance-active radical species (1(+) and 3(+)) leads to [Ru-II(pap)(2)(L)](2+) involving fully oxidized L-0 in 1(2+) and 3(2+); the same in 2(+) results in a radical species [Ru-II(pap)(2)(L'(center dot))](2+) (2(2+)). Successive reductions in each case are either associated with pap or L/L'(-)-based orbitals, revealing a competitive scenario relating to their pi-accepting features. The isolated or electrochemically generated radical species either by oxidation or reduction exhibits near-IR transitions in each case, attributing diverse electronic structures of the complexes in accessible redox states. |
| Databáze: | OpenAIRE |
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