title: Second hyperpolarizability of ethynyl-linked azobenzene molecular wires.
abstract: A series of oligomers consisting of ethynyl-linked azobenzene units was prepared using Pd-catalyzed cross coupling. The linear and nonlinear optical properties of the oligomers were investigated. The molecular second hyperpolarizability, gamma, followed the power law gamma proportional, variant n(2.12+/-0.05) (n is the number of repeat units) for unusually large molecular lengths exceeding 360 conjugated bonds (>49 nm). The exceptional exciton delocalization length is attributed to the rigidity of the conjugated backbone.
authors.affiliation: Department of Chemistry, Virginia Commonwealth University, 1001 W. Main Street, Richmond, Virginia 23284-2006, USA.
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Humphrey
authors.forename: Kimberly M
authors.initials: KM
authors.lastname: Lott
authors.forename: Michael E
authors.initials: ME
authors.lastname: Wright
authors.forename: Darius
authors.initials: D
authors.lastname: Kuciauskas