Syntheses and spectroscopic and quadratic nonlinear optical properties of extended dipolar complexes with ruthenium(II) ammine electron donor and N-methylpyridinium acceptor groups.
In this paper, we describe the extremely unusual optical properties of Ru(II)-based electron donor-acceptor (D-A) polyene and some closely related chromophores. For three different polyene series, the intense, visible d-->pi* metal-to-ligand charge-transfer bands unexpectedly blue-shift as the number of E-ethylene units (n) increases from 1 to 3, and the static first hyperpolarizabilities beta(0) determined via hyper-Rayleigh scattering and Stark spectroscopy maximize at n = 2, in marked contrast to other known D-A polyenes in which beta(0) increases steadily with n. Time-dependent density-functional theory and finite field calculations verify these empirical trends, which arise from the orbital structures of the complexes. This study illustrates that transition metal-based nonlinear optical chromophores can show very different behavior when compared with their more thoroughly studied purely organic counterparts.
Coe
Benjamin J
BJ
Department of Chemistry, University of Manchester, Oxford Road, Manchester, United Kingdom M13 9PL. b.coe@man.ac.uk
Jones
Lathe A
LA
Harris
James A
JA
Brunschwig
Bruce S
BS
Asselberghs
Inge
I
Clays
Koen
K
Persoons
André
A
Garín
Javier
J
Orduna
Jesús
J