Showing papers by "Thomas A. Hamor published in 1978"
20 citations
10 citations
TL;DR: A Fortran IV computer program for structure factor calculation and least-squares refinement of crystal structures was proposed by HELLNER et al. as discussed by the authors, which can be found in the Kynoch Press.
Abstract: BATS, J. W. & COPPENS, P. (1977). Acta Cryst. B33, 1542-1548. CARON, A. & DONOHUE, J. (1969). Acta Cryst. B25, 404. COPPENS, P. & HAMILTON, W. C. (1970). Acta Cryst. A26, 71-83. FINGER, L. (1972). A Fortran IV computer program for structure factor calculation and least-squares refinement of crystal structures. Carnegie Inst. of Washington. FRITCHIE, C. J. (1966). Acta Crvst. 20, 27-36. HAMILTON, W. C. (1965). Aeta Cryst. 18, 502-5 I0. HELLNER, E. (1977). Aeta Crvst. B33, 3813-3816. International Tables for X-ray Crystallography (I 974). Vol. IV. Birmingham: Kynoch Press. JOHNSON, C. K. (1965). ORTEP. Report ORNL-3794. Oak Ridge National Laboratory, Tennessee. MULLEN, D. 8~. HELLNER, E. (1977). Acta Cryst. B33, 3816-3822. PRYOR. A. 8¢. SANGER, P. L. (1970). Acta Crvst. A26, 543-558. ZACHAR1ASEN, W. H. (1967). Acta Cryst. 23, 558-564.
5 citations
5 citations
TL;DR: The mean P C bond lengths for the sulphide and selenide derivatives are almost exactly the same (~1.812 A) but are noticeably longer in the phosphine derivatives as mentioned in this paper.
Abstract: The mean P C bond lengths for the sulphide and selenide are almost exactly the same (~1.812 A) but are noticeably longer in the phosphine (1.835/k). The lengths do not vary significantly from those observed in the o-tolyl derivatives and it would seem, therefore, that the position of substitution of the methyl group has no direct effect upon them. The length of the P C bonds seems to be influenced by two factors only: the valence state of the P atom and, for individual bond lengths, the degre~ of intermolecular steric hindrance.
4 citations
4 citations
4 citations
TL;DR: In this paper, the structure of the title compound is determined from three-dimensional counter data and refined to R 0.045 for 1 634 observed amplitudes, which is consistent with an n-σ* type of interaction.
Abstract: Crystals of the title compound are monoclinic, with unit-cell dimensions a= 7.463(5), b= 13.72(l), c= 13.90(1)A, and β= 100.35(5)°, space group P21/c, and Z= 4. The structure has been determined from three- dimensional counter data and refined to R 0.045 for 1 634 observed amplitudes. The P–N bond length [1.614(2)A] indicates a considerable degree of π bonding, and the conformation about this bond is consistent with an n–σ* type of interaction. Comparison with structural data on related molecules shows that the π bonding is enhanced by electronegative substituents on the phosphorus atom. The two Pri groups are orientated differently with respect to the P–N bond. These results are discussed in relation to n.m.r. spectroscopic data which indicate that the Pri groups are non-equivalent at low temperature.
4 citations