Y. Kai, N. Yasuoka, N. Kasai
Nov 1, 1972
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0
Influential Citations
19
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The molecular structure of a stereospecific (isotactic) polymerization catalyst of the acetaldehyde-monomer complex, [Me2Al·O·CPh: NPh,MeCHO]2, has been determined on the basis of three-dimensional X-ray data collected photographically. The crystal belongs to the orthorhombic system (space group Pcca) with four dimer formula units in a cell with the dimensions of: a=15.83(3), b=12.61(1), and c=17.66(1) A. The structure was established by the heavy-atom method and refined by block-diagonal, least-squares procedure. The molecule is dimeric and has a C2-2 symmetry. A monomer molecule, acetaldehyde, is inserted in the Al–N bond of the original polymerization catalyst. The oxygen atom bridges both aluminum atoms, Al–O=1.858(6) and 1.985(6) A. The α-carbon atom of acetaldehyde bonds to the nitrogen atom of the amide moiety, C–N=1.469(12) A. The aluminum atom is penta-co-ordinated and has a trigonal bipyramidal conformation.