Crystal and molecular structure of tetraphenylsilane

The crystal structure of tetrakis(pentafluorophenyl)silane

“…However, the aryl ring is distorted from idealized geometry as indicated by the large variation in bond lengths and angles, although the individual values cited in Table 3 are in close agreement with those observed in other pentafluorophenyl compounds (Karipides, Forman, Thomas & Reed, 1974). An important exception is the apical C(2)-C(1)-C(6) angle of 114.1 (3) °, which is significantly smaller than the 116.1 (7) ° found for the corresponding angle in tetraphenylsilane (Glidewell & Sheldrick, 1971). This decrease in the magnitude of the apical angle in the perfluorophenylsilane is consistent with the strong oelectron withdrawing properties of a pentafluorophenyl ring and supports the arguments of Domenicano, Vaciago & Coulson (1975a,b) concerning the skeletal deformations of substituted benzenes.…”

Molecular Motion in Tetraphenyltin Studied by NMR

“…As no information on the positions of protons has been given in the X-ray analysis [4][5][6], they were generated assuming the C-H bond length of 1.08 Ä and the C-C-H angle of 120°. The intramolecular part of the second moment M-> was 2.9 • 10~2 mT 2 , while the intermolecular part was 4.58 • 10~2 mT 2 , so the total second moment value was 7.48 • 10 -2 mT 2 , which is in good agreement with the experimental value of 7.4 • 10~2 mT 2 . A slight increase in M 2 observed for temperatures below 200 K, can be caused by an increase in the intermolecular part due to a contraction of the crystal lattice.…”

“…3 (solid line), while the activation parameters are collected in Table 1. The high-temperature process of high activation energy (82.4 kJ/mol) and the corresponding reduction of the second moment 3.12-10~2 mT 2 can be attributed to the isotropic reorientation of the tetraphenyltin molecules. In case of istotropic reorientation, the intramolecular part of the second moment is reduced to zero, whereas it is very difficult to the estimate the reduction of the intermolecular part.…”

“…The compounds crystallise in the tetragonal system, space group P42]C, Z=2 [1][2][3][4][5][6][7]. The molecule symmetry in the crystal is 4.…”

A refinement of the crystal structure of tetraphenylmethane: three independent redeterminations

“…Tetraphenylmethane is a member of an isostructural series which includes the compounds with Si,vGe, Sn and Pb as the central atom (Ismailzade & Zdanov, 1952;Busetti, Mammi, Signor & Del Pra, 1967;Chieh & Trotter, 1970;Glidewell & Sheldrick, 1971;Chieh, 1971Chieh, , 1972Karipides &Haller, 1972). Because of their relative simplicity, these structures have been the object of a theoretical calculation aimed at predicting both the intramolecular geometry and the intermolecular packing (Ahmed, Kitaigorodsky & Mirskaya, 1971).…”