MECHANISTIC INVESTIGATIONS ON THE FORMATION OF SUPRAMOLECULAR CYLINDRICAL SHAPED OLIGOMERS AND POLYMERS BY LIVING RING-OPENING METATHESIS POLYMERIZATION OF A 7-OXANORBORNENE MONOMER SUBSTITUTED WITH 2 TAPERED MONODENDRONS

The synthesis of the monomer -bis[[[(3,4,5-tris((4-(dodecyl-1-oxy)benz yl)oxy)]- benzyl)oxy]carbonyl]-7-oxabicyclo[2.2.1] (4), containing two tapered monodendrons and its living ring-opening metathesis polymeriz ation initiated with RuCl2(=CHPh)(PCy3)(2) are discussed. Oligomers an d polymers with narrow molecular weight distribution (M-w/M-n = 1.06-1 .29) and degrees of polymerization (DP) from 6 to 120, which correspon d to M-n from 12 600 to 252 800, were synthesized and characterized. T he monomer (4) and the corresponding polymers (5) self-assemble into d isklike and cylindrical shapes which produce an enantiotropic hexagona l columnar (Phi(h)) liquid crystalline (LC) phase. The analysis of the Phi(h) phase of the monomer, oligomers, and polymers as a function of the DP reveals four regions and mechanisms for the generation of the Phi(h) phase, i.e., below the DP which forms a disklike molecule, belo w the DP which corresponds to the maximum length of a disklike molecul e (DP = 26), up to the DP which corresponds to the persistence length of the rodlike cylinder (DP = 64), and above this value.