resumo
The heterogeneous phase reaction of excess sodium salt of 2-hydroxypyridine (OHpy) with [Ru(kappa C-2,O-RL)(PPh3)(2)(CO)Cl] (1) afforded complexes of the type [Ru(kappa C-1-RL)(PPh3)(2)(CO)(Opy)] (2) in excellent yield [kappa C-2,O-RL is 4-methyl-6-((N-R-arylimino)methyl)phenolato-C-2,O), kappa C-1-RL is 4-methyl-6-((N-R-arylimino)methyl)phenol-C-2) and R is H, Me, OMe, Cl]. The chelation of Opy is attended with the cleavage of Ru-O and Ru-Cl bonds and iminium-phenolato -> imine-phenol prototropic shift. The 1 -> 2 conversion is irreversible and the type 2 species are thermodynamically more stable than the acetate, nitrite, and nitrate complexes of 1. The spectral (UV-vis, IR, NMR) and electrochemical data of the complexes are reported. In dichloromethane solution the complexes display one quasi-reversible Ru-III/Ru-II cyclic voltammetric response with E-1/2 in the range 0.65-0.69 V versus Ag/AgCl. The crystal and molecular structures of [Ru(kappa C-1-HL)(PPh3)(2)(CO)(Opy)]center dot 2C(6)H(6)center dot 0.5H(2)O, 2(H)center dot 2C(6)H(6)center dot 0.5H(2)O and [Ru(kappa C-1-ClL)(PPh3)(2)(CO)(Opy)]center dot 2C(6)H(6)center dot 0.25H(2)O, 2(Cl)center dot 2C(6)H(6)center dot 0.25H(2)O are reported, which revealed a distorted octahedral RuC2P2NO coordination sphere. The pairs (P,P), (C,O), and (C,N) define the three trans directions. The electronic structures of the complexes are also scrutinized by density functional theory. [GRAPHICS] .
palavras-chave
ZETA VALENCE QUALITY; CRYSTAL-STRUCTURE; BASIS-SETS; C-BOND; OSMIUM; FAMILY; COMPLEXES; CHEMISTRY; INSERTION
categoria
Chemistry
autores
Islam, A; Ghosh, MK; Mondal, S; Brandao, P; Chattopadhyay, S
nossos autores
Paula Cristina Ferreira da Silva Brandão
Investigador Auxiliaragradecimentos
M. K. Ghosh and S. Mondal thank University Grants Commission (UGC), India, for the predoctoral fellowships. The crystallographic studies were supported by CICECO-Aveiro Institute of Materials (UID/CTM/50011/2013), financed by National Funds through the FCT/MEC and co-financed by QREN-FEDER through COMPETE under the PT2020 Partnership Agreement. Financial supports from the Department of Science and Technology, Government of India (no. SR/S1/IC-65/2010) and the Council of Scientific & Industrial Research, New Delhi, India (no. 01(2898)/17/EMR-II) are gratefully acknowledged, University of Kalyani for infrastructural facilities. The support of DST under FIST program to the Department of Chemistry, University of Kalyani is also acknowledged.