Self assembled asymmetrically substituted polydiacetylene as a novel second order NLO material

Summary form only given. Polymer chains of a novel asymmetric polydiacetylene, poly((8-butoxy carbonyl)methyl urethanyl) 1-(5-pyrimidyl)-octa-1,3-diyne(BPOD) self assemble in an acentric stable polar organization upon spin coating. Spontaneous alignment of the urethane moiety caused by the intramolecular hydrogen bonds between the side groups appears to be responsible for this organization. An abrupt decrease, of SH intensity at around 130/spl deg/C is found to be closely related to the breaking of noncentrosymmety in the films in conjunction with the disruption of these intramolecular hydrogen bonds. The changes observed were reversible below 130/spl deg/C but become irreversible above this temperature. Dielectric and infrared spectroscopy confirm the relaxation of the stable hydrogen bonded polar organization at higher temperatures. The invention of this self assembling second order NLO polymer also opens up numerous possibilities in molecular design for further optimization of properties.