Second Hyperpolarizability of Ethynyl-Linked Azobenzene Molecular Wires
journal contributionposted on 24.11.2005, 00:00 by Jonathan L. Humphrey, Kimberly M. Lott, Michael E. Wright, Darius Kuciauskas
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, γ, followed the power law γ ∝ n2.12±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.