The crystal structue of a highly isotactic optically active alternating styrene-carbon monoxide copolymer, obtained with a chiral cationic Pd(II) bioxazoline complex, is determined and refined from powder X-ray diffraction data with the Rietveld method. The unit cell is monoclinic, P2(1) space group, with a = 8.367 Angstrom, b = 7.574 Angstrom (chain repeat), c = 5.47 Angstrom, beta = 110.0 degrees, and Z = 2 monomeric unis with a density of 1.32 g/cm(3); The observed chain conformation has a repeat period almost identical to that observed in syndiotactic copolymers in spite of the different symmetry connecting the monomeric units, s(2/1) instead of tc. The different symmetry connecting the monomeric units along the chain influences significantly the reciprocal orientation of the phenyl groups within each chain and between different chains.
Crystal structure of the isotactic alternate copolymer between carbon monoxide and styrene / S., Bruckner; DE ROSA, Claudio; P., Corradini; W., Porzio; A., Musco. - In: MACROMOLECULES. - ISSN 0024-9297. - STAMPA. - 29:(1996), pp. 1535-1539. [10.1021/ma9510505]
Crystal structure of the isotactic alternate copolymer between carbon monoxide and styrene
DE ROSA, CLAUDIO;
1996
Abstract
The crystal structue of a highly isotactic optically active alternating styrene-carbon monoxide copolymer, obtained with a chiral cationic Pd(II) bioxazoline complex, is determined and refined from powder X-ray diffraction data with the Rietveld method. The unit cell is monoclinic, P2(1) space group, with a = 8.367 Angstrom, b = 7.574 Angstrom (chain repeat), c = 5.47 Angstrom, beta = 110.0 degrees, and Z = 2 monomeric unis with a density of 1.32 g/cm(3); The observed chain conformation has a repeat period almost identical to that observed in syndiotactic copolymers in spite of the different symmetry connecting the monomeric units, s(2/1) instead of tc. The different symmetry connecting the monomeric units along the chain influences significantly the reciprocal orientation of the phenyl groups within each chain and between different chains.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.