Regioregular organocobalt polyethers (3 and 4) and polyesters (5–8) have been prepared by the polycondensation of regioisomerically pure (h 4-tetraarylcyclobutadiene)cobalt-containing bis-phenols (9 and 10) with aliphatic or aromatic comonomers. The diols (9) offered rigid-rod p-terphenyl-like structural units, while their isomers (10) led to 90° kinks in polymeric backbones. The polymers (3, 5 and 7 ¼ 'odd’ series) were derived from the bis-phenols (9), while their isomers (4, 6 and 8 ¼ 'even’ series) resulted from 10. Most of the polymers (3–8) exhibited good solubilities in common organic solvents. In the case of the isomeric polyesters with aromatic backbones (7 and 8), the latter were more soluble, indicative of their higher configuration entropies. Glass transition temperatures of the 'odd’ and 'even’ isomers were similar, irrelative to the kinks in their backbones, but they showed good correlation with aliphatic-to-aromatic mass ratios and rigidities of the main chains. The polymers of the 'odd’ series exhibited crystalline and liquid crystalline (polyesters, 7) phases, while their 'even’ isomers remained amorphous. Correlations between mesomorphic properties and the structure of the repeating units have been discussed.
Посилання на статтю:
Synthesis and properties of regioregular polyethers and polyesters with (h 4-cyclobutadiene)cobalt moieties in the main chain1 / I.L. Rozhanskii, I. Tomita, T. Endo // Polymer. – 1999. – N 40. – P. 1581–1591.