LONG-RANGE CHIRAL INDUCTION IN CHEMICAL-SYSTEMS WITH HELICAL ORGANIZATION - PROMESOGENIC MONOMERS IN THE FORMATION OF POLY(ISOCYANIDE)S ANDIN THE ORGANIZATION OF LIQUID-CRYSTALS

The preparation of optically active poly(isocyanide)s derived from chi ral promesogenic monomers is reported. Remarkably, the stereogenic car bon atom in the monomer is able to pass its chiral ''information'' to the growing polymer backbone which is at least 14 atoms (approximately 16 Angstrom) remote from it. The sense of helical induction in these conformationally rigid polymers is compared to the helical sense of th e cholesteric phases, as well as to the helical senses of chiral smect ic C phases, induced by the monomers in nematic and smectic C phases, respectively. Both relate to the odd-even rules for chiral sense chang es in liquid crystalline phases. The role of noncovalent interactions in the polymerization has been proven by performing the reactions at v arious concentrations and in different solvents-the chiral induction f rom monomer to polymer is greatest in most concentrated reactions and in solvents with a balance between high dipolarity-polarizability and low hydrogen bond accepting and cavitational terms, as determined by a n LSER analysis.