Synthesis, Crystal Structure, and Second‐Order Nonlinear Optical Properties of Ruthenium(<scp>II</scp>) Complexes with Substituted Bipyridine and Phenylpyridine Ligands

Abstract

Abstract Two new ruthenium( II ) complexes of formula [Ru(bpy) 2 (L 1 )][PF 6 ] and [Ru(bpy) 2 (L 2 )][PF 6 ] 2 are reported. HL 1 is a (nitrophenyl)ethenyl‐substituted phenylpyridine ligand, and L 2 is the bipyridine analogue of HL 1 . The X‐ray crystal structure of [Ru(bpy) 2 (L 1 )][PF 6 ] has been solved, and the compound is found to crystallize in the monoclinic C 2/ c space group. The electronic spectrum of the cyclometalated derivative [Ru(bpy) 2 (L 1 )][PF 6 ] exhibits a low‐lying transition that is red‐shifted from 454 to 546 nm relative to that of the parent bipyridine‐based complex, which reveals an important charge‐transfer character. To support this assumption, the nonlinear optical properties were investigated by the hyper‐Rayleigh scattering technique and indicate a molecular static hyperpolarizability ( β 0 ) equal to 230 × 10 –30 cm 5 esu –1 . (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2006)