Functionalized diacetylenes for nonlinear optical applications: Synthesis,characterization, and the properties of their monolayers

Synthesis and characterization of DA(8/1)OMe (14-(4'-[(methoxy)methoxy] bip henyl)-10,12-tetradecadiynoic acid) and DA(8/1)NBP (14-(4'-[(nitro)methoxy] biphenyl)-10,12-tetradecadiynoic acid) are presented. Monolayers of DA(8/1 )OMe at gas-water interface were investigated. It does not forma stable mon olayer nor does it undergo polymerization at the gas-water interface. Howev er, the Ba2+ and Cd2+ salts formed stable monolayer that polymerized. Polym erization was confirmed by Raman spectroscopy. The diacetylene analog with the more polar tail group, DA(8/1)NBP, does not form a monolayer and underg o polymerization regardless of the subphase condition. A mixed monolayer of DA(8/1)OMe and DA(8/1)NBP forms a true monolayer if the composition of DA( 8/1)NBP is 50% or less. (C) 1999 John Wiley & Sons, Inc.