title: Synthesis, linear, and quadratic-nonlinear optical properties of octupolar D3 and D2d bipyridyl metal complexes.
abstract: A series of D3 (Fe(II), Ru(II), Zn(II), Hg(II)) and D2d (Cu(I), Ag(I), Zn(II)) octupolar metal complexes featuring different functionalized bipyridyl ligands has been synthesized, and their thermal, linear (absorption and emission), and nonlinear optical (NLO) properties were determined. Their quadratic NLO susceptibilities were determined by harmonic light scattering at 1.91 microm, and the molecular hyperpolarizability (beta0) values are in the range of 200-657 x 10(-30) esu for octahedral complexes and 70-157 x 10(-30) esu for tetrahedral complexes. The octahedral zinc(II) complex 1 e, which contains a 4,4'-oligophenylenevinylene-functionalized 2,2'-bipyridine, exhibits the highest quadratic hyperpolarizability ever reported for an octupolar derivative (lambdamax=482 nm, beta1.91(1 e)=870 x 10(-30) esu, beta0(1 e)=657 x 10(-30) esu). Herein, we demonstrate that the optical and nonlinear optical (NLO) properties are strongly influenced by the symmetry of the complexes, the nature of the ligands (donor endgroups and pi linkers), and the nature of the metallic centers. For example, the length of the pi-conjugated backbone, the Lewis acidity of the metal ion, and the increase of ligand-to-metal ratio result in a substantial enhancement of beta. The contribution of the metal-to-ligand (MLCT) transition to the molecular hyperpolarizability is also discussed with respect to octahedral d6 complexes (M=Fe, Ru).
authors.affiliation: Organométalliques et Catalyse, Chimie et Electrochimie Moléculaires, UMR 6509 CNRS-Université de Rennes 1, Institut de Chimie de Rennes, Campus de Beaulieu, 35042 Rennes Cedex, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Maury
authors.forename: Lydie
authors.initials: L
authors.lastname: Viau
authors.forename: Katell
authors.initials: K
authors.lastname: Sénéchal
authors.forename: Brigitte
authors.initials: B
authors.lastname: Corre
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Guégan
authors.forename: Thierry
authors.initials: T
authors.lastname: Renouard
authors.forename: Isabelle
authors.initials: I
authors.lastname: Ledoux
authors.forename: Joseph
authors.initials: J
authors.lastname: Zyss
authors.forename: Hubert
authors.initials: H
authors.lastname: Le Bozec
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry*; D019216:Metals, Heavy / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D019216:Metals, Heavy; D009942:Organometallic Compounds; D015082:2,2'-Dipyridyl