title: Syntheses and properties of two-dimensional charged nonlinear optical chromophores incorporating redox-switchable cis-tetraammineruthenium(II) centers.
abstract: In this article, we describe a series of new complex salts in which electron-donating cis-{Ru(II)(NH3)(4)}(2+) centers are connected to two electron-accepting N-methyl/aryl-pyridinium groups. These V-shaped complexes contain either monodentate 4,4'-bipyridyl-derived ligands or related chelates based on 2,2':4,4":4',4'''-quaterpyridyl and have been characterized by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. Molecular quadratic nonlinear optical (NLO) responses beta have been determined by using hyper-Rayleigh scattering at 800 nm and also via Stark (electroabsorption) spectroscopic studies on the intense, visible d --> pi metal-to-ligand charge-transfer bands. These experiments reveal that these dipolar pseudo-C(2v)chromophores exhibit two substantial components of the beta tensor, beta(zzz)and beta(zyy), with the difference between them being most marked for the nonchelated systems. Time-dependent density-functional theory and finite field calculations serve to further illuminate the electronic structures and associated linear and NLO properties of the new chromophoric salts.
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Coe
authors.forename: James A
authors.initials: JA
authors.lastname: Harris
authors.forename: Lathe A
authors.initials: LA
authors.lastname: Jones
authors.forename: Bruce S
authors.initials: BS
authors.lastname: Brunschwig
authors.forename: Kai
authors.initials: K
authors.lastname: Song
authors.forename: Koen
authors.initials: K
authors.lastname: Clays
authors.forename: Javier
authors.initials: J
authors.lastname: Garín
authors.forename: Jesús
authors.initials: J
authors.lastname: Orduna
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Coles
authors.forename: Michael B
authors.initials: MB
authors.lastname: Hursthouse