Revisiting oxo-centered carbonyl-triruthenium clusters: investigating CO photorelease and some spectroscopic and electrochemical correlations

Autor(es)

Moreira, Mariete B. ; Da Silva, Camila F. N. ; Pesci, Rafaela B. P. ; Deflon, Victor M. ; Nikolaou, Sofia

• Tipo de documento: Artigo Científico
• Fonte: DALTON TRANSACTIONS; v. 45, n. 42, p. 16799-16809, 2016.
• Citações Web of Science: 4

Resumo

We synthesized and characterized a series of oxo-centered carbonyl-triruthenium complexes with the general formula {[}Ru3O(CH3COO)(6)(L)(2)(CO)], where L = 2,6-dimethylpyrazine (dmpz) (1), isonicotinamide (adpy) (2), 4-acetylpyridine (acpy) (3), 3-methylpyridine (3-pic) (4), 4-methylpyridine (4-pic) (5), 4-tert-butylpyridine (4-tbpy) (6), 4-(dimethyl) aminopyridine (dmap) (7), or 4-aminopyridine (ampy) (8); we also investigated the photoreactivity of these complexes. Single-crystal X-ray diffraction helped to elucidate the structures of 1 center dot H2O, 7 center dot C2H4Cl2, and 8. The unit cell of 8 is composed of four cluster units; the hydrogen bonds between the amino groups of the terminal ligand of a neighboring molecule and the oxygen atoms of CO or acetate bridging ligands hold these cluster units together. The spectroscopic (NMR, UV-visible, and IR) and the electrochemical properties (cyclic voltammetry) of these complexes correlated with the ancillary ligands in terms of their sigma-donating and pi-accepting characteristics. The molecular orbital and the electronic localized description of the {[}Ru3O]-CO unit helped to rationalize the correlations. The photoreactivity of compounds 1-8 was investigated by laser excitation at 377 nm. Given the CO photorelease quantum yields, sigma-donor ligands and aqueous medium (more polar) stabilized the charge-transfer excited state that culminated in CO photosubstitution, leading to higher Phi values. (AU)

• Processo FAPESP: 15/20302-7 - Uso de anti-inflamatórios não esteroidais, azanaftalenos e fenazinas como ligantes na obtenção de carboxilatos bi- e trinucleares de rutênio com potencial atividade antialérgica, tumoricida e tripanocida
• Beneficiário: Sofia Nikolaou
• Modalidade de apoio: Auxílio à Pesquisa - Regular