Accession Number : AD0687515

Title :   X-RAY CRYSTALLOGRAPHY OF THE PHENYL-TRIPHOSPHONITRILES. III. THE CRYSTAL STRUCTURE OF 2, 2, 4, 4, 6, 6-HEXAPHENYL-CYCLOTRIPHOSPHAZATRIENE,

Corporate Author : NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA (ONTARIO) DIV OF PURE PHYSICS

Personal Author(s) : Ahmed,F. R. ; Singh,P. ; Barnes,W. H.

Report Date : 12 FEB 1968

Pagination or Media Count : 13

Abstract : The crystal structure of 2,2,4,4,6,6-hexaphenyl cyclotriphosphazatriene, (C6H5)6P3N3, has been determined from three-dimensional Patterson, Fourier, and difference syntheses, and has been refined by least squares to an R index of 0.054 for 2900 observed reflections. The cyclotriphosphazene ring, P3N3, has an irregular slight chair form. The six chemically equivalent P-N bonds are statistically equal in length (mean, 1.597 A), as are the six P-C bonds (mean, 1.804 A). The mean bond angles are 103.8 deg for C-P-C, 117.8 deg for N-P-N, and 122.1 deg for P-N-P. The average C-C bond length in the aromatic phenyl rings is 1.379A. The results are compared with available data for other trimeric phosphonitriles, and some systematic effects of the relative electronegativities of the ligands on bond lengths and angles are discussed. (Author)

Descriptors :   (*PHOSPHORUS HETEROCYCLIC COMPOUNDS, *CRYSTAL STRUCTURE), (*NITROGEN HETEROCYCLIC COMPOUNDS, CRYSTAL STRUCTURE), X RAY DIFFRACTION, GEOMETRY, CHEMICAL BONDS, CANADA

Subject Categories : Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE