novel triruthenium nitrosyl bearing a quinolinic ligand: a comparison of its spectroscopic behavior with its pyridine analogue

Autor(es)

Portela dos Santos, Nicolle Azevedo ^[1] ; Silva, Amanda Batista ^[1] ; Neves da Silva, Camila Fontes ^[2] ; Pereira Alexiou, Anamaria Dia ^[1] ; Nikolaou, Sofia ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Filosofia, Dept Quim, Lab Atividade Biol & Quim Supramol Compostos Coor, Av Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Inst Quim, Dept Bioquim, Lab Proc Fotoinduzidos & Interfaces LPFI, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: NEW JOURNAL OF CHEMISTRY; v. 46, n. 10, p. 4819-4826, MAR 7 2022.
• Citações Web of Science: 0

Resumo

We present the novel compound {[}Ru3O(CH3COO)(6)(iq)(2)NO]PF6, iq = isoquinoline. Its electronic spectrum displays three charge-transfer bands between 350 and 550 nm and a band due to intra-cluster transitions centered at metallic levels at 701 nm (842 L mol(-1) cm(-1)). This compound releases NO(g) under UV irradiation (lambda(irrad) = 365 nm), with phi = 0.23 in acetonitrile solution. Its H-1 NMR spectrum shows attenuated paramagnetic anisotropy of the {[}Ru3O] unit. As for IR spectroscopy, the nu(NO) stretching band (1904 cm(-1)) arises at a relatively high frequency, suggesting that the NO ligand has important NO+ character. To understand the nature of the {[}Ru3O]-NO metallic core, we have compared the spectroscopic data of {[}Ru3O(CH3COO)(6)(iq)(2)NO]PF6 with the data of pyridinic analogues bearing 4-acetylpyridine, 3-methylpyridine, pyridine, 4-methylpyridine, or 4-tert-butylpyridine as ancillary ligands. Except for the value of nu(NO), the introduction of a ligand (iq) bearing a second aromatic ring does not impact the other spectroscopic properties of the metallic core. The nitrosyl compounds with the general formula {[}Ru3O(CH3COO)(6)(L)(2)NO]PF6 share similarities with both symmetric compounds ({[}(RuRuRuO)-Ru-III-Ru-III-O-III(CH3COO)(6)(L)(3)]PF6) and with the isoelectronic carbonyl compounds ({[}(RuRuRuO)-Ru-III-Ru-III-O-II(CH3COO)(6)(L)(2)CO]) and there is no clear evidence for the role of pi-backbonding in their spectroscopic characteristics. These findings point to the presence of two metallic subunits: a [RuNO](6) portion with high covalence and electron pairing, and thus less sensitivity to variations in L; and a second subunit, Ru-2(III,III), which is susceptible to perturbations to its electronic density by sigma-donation from L. This analysis finally suggests that the triruthenium nitrosyl compounds constitute multiconfigurational systems with relevant contributions from both (RuRuRuIII)-Ru-III-Ru-III-NO0 and (RuRuRuII)-Ru-III-Ru-III-NO+ configurations. (AU)

• Processo FAPESP: 21/02802-3 - Estudo de reatividade redox e liberação de óxido nítrico e monóxido de carbono em carboxilatos trinucleares de rutênio
• Beneficiário: Amanda Batista Silva
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 19/03195-3 - Desenvolvimento de novos complexos de rutênio eficientes para causar danos à membrana e melhorar a resposta da tfd
• Beneficiário: Camila Fontes Neves da Silva
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 18/18060-3 - Uso de estruturas supramoleculares inorgânicas com vistas ao desenvolvimento de moléculas funcionais e liberação controlada de espécies bioativas
• Beneficiário: Sofia Nikolaou
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/14170-1 - Estudo de potenciais liberadores de óxido nítrico baseado em complexos de rutênio e ligantes azanaftalenos
• Beneficiário: Nicolle Azevedo Portela dos Santos
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica