Molecular arrangement and recognition of a new bolaform cinnamic acid derivative in LB films

A bolaamphiphile containing cinnamic acid moiety, [4-(10-hydroxydecanyloxy)-10-hydroxydecanylcinnamate, abbreviated HDC], was synthesized and the LB films of HDC were studied. It was found from the results of pi-A isotherms that multilayers of HDC were formed at the air/water interface. The photoreaction of HDC in LB films induced by UV light was investigated with UV and IR measurements. Photodimerization also took place in the mixed LB films of HDC and 1,16-hexadecanediol. The spectra results showed that the HDC molecules assembled orderly due to the separated recognition of pi-pi interaction and the zigzag stacking of methylene groups. XRD studies indicated that bilayers formed in the LB films with a tilt angle of 58.8 degrees and 53.2 degrees before and after UV irradiation, respectively. A packing model of HDC was also proposed.