SUPRAMOLECULAR CHIRALITY IN NEW CHIRAL LIQUID CRYSTAL AZOPOLYMERS OBTAINED BY ATRP

We present the synthesis by ATRP and the characterization of monodisperse chiral azopolymers of well-controlled structure (linear and three-arms star shaped) and different average molecular weights. These new azopolymers include L-lactic residues in the side chain, which can transmit their chirality to a supramolecular organization of the liquid crystal twisted grain boundary A phase (TGBA). It is possible to photomodulate the chiroptical properties of thin films of these polymers by irradiation with circularly polarized (CP) light of one single left (L) or right (R) rotation sense. To our best knowledge, these are the first examples of reversible chiroptical switching between two enantiomeric suprastructures obtained by a native chiral liquid-crystal TGB phase