Synthesis, Characterization, and Charge Distribution of Bis(4-t-butylpyridine)bis(3,5-di-t-butylquinone)ruthenium

摘要

The synthesis and characterization of bis(4-t-butyl-pyridine)bis(3,5-di-t-butylquinone)ruthenium is reported. A crystallographic molecular structure determination carried out on the complex has shown that it exists as the trans isomer and that ligand C-O lengths are relatively long for a semiquinone complex being at the bottom end of the range observed for catecholate complexes. Both quinone ligands appear structurally and electronically equivalent. The complex is diamagnetic and shows a well-resolved spectrum. Electrochemically, the complex undergoes four redox processes, all of which most likely involve both metal and quinone ligands. There are charge-transfer bands in the visible region, and an exceptionally intense and structured band in the near infrared region. The ground state is viewed as a mixture of bis(4-t-butylpyridine)bis(3,5-di-t-bu tylsemliquinone0ruthenium(II) and bis(4-t-butylpyridine)bis(3,5-di-t-butylcatecholato)ruthenium (IV), with the former dominant.