A NOVEL SUPRAMOLECULAR SELF-ASSEMBLY THIN-FILM WITH SPONTANEOUS POLARORDER

A novel supramolecular thin film in which a non-linear optical (NLO) c hromophore is uniaxially included in the helical cavity of amylose, re vealed a spontaneous self-assembly with a long-range polar order of th e chromophores perpendicular to the film surface. This was manifested by a significantly large second harmonic generation (SHG) observed fro m solution-cast solid supramolecular thin films on a glass substrate w ithout any external field. Such self-assembly/self-poling and the long -term polar stability of the supramolecular chromophores are thought t o be due to the helical rigid-rod structure, their dipolar and/or chir al recognition in the ordering process following the polar initiation through the interface interaction of the chromophore with the glass su bstrate, and H-bonding among the ordered supramolecules. (C) 1998 Else vier Science S.A. All rights reserved.