881175-93-5Relevant academic research and scientific papers
Comparison of basicity of the diimine and quinoid group of 1,10-phenanthroline-5,6-dione ligated on Pt(II)
Okamura, Rei,Fujihara, Tetsuaki,Wada, Tohru,Tanaka, Koji
, p. 106 - 112 (2006)
A platinum(II) complex bearing 1,10-phenanthroline-5,6-dione (phenO 2), [PtCl(phenO2-N,N′)(PPh3)]+ ([2]+) was newly prepared and characterized. An X-ray crystallographic study of [2](PF6) revealed that the phenO 2 ligand coordinates to platinum with the N,N′-chelate form. The basicity of the quinoid part of phenO2 in [2]+ and of the diimine one in [Pt(phenO2-O,O′)(PPh3) 2] with an O,O′-chelate ring (3) was evaluated in the absence and the presence of Li+ by means of UV-vis spectroscopy and cyclic voltammetry. The quinoid group in [2]+ practically had no ability to bind Li+, but induced on anodic potential shift of the phenO 2 localized redox potential by 850 mV due to the strong interaction between the reduced form of [2]+ and Li+. Undeniably, a weak interaction of Li+ with the diimine moiety of free phenO 2 (K = 3.6 M-1) is greatly enhanced in the interaction between Li+ and the diimine site in 3 because of the electron donation from the catecholato group of the complex.
