Accession Number : AD0638051

Title :   THE RELATIVE ACCEPTOR POWERS OF SILICON AND GERMANIUM TETRAHALIDES TOWARD PYRIDINE AND ISOQUINOLINE.

Corporate Author : MCGILL UNIV MONTREAL (QUEBEC) INORGANIC CHEMISTRY LAB

Personal Author(s) : Miller,J. M. ; Onyszchuk,M.

Report Date : 23 JUN 1964

Pagination or Media Count : 1

Abstract : Measurements were made, with a precision calorimeter, the heats of reaction at 25C of silicon and germanium tetrahalides with pyridine (py, as the neat liquid) and isoquinoline (iq, as a 1% solution in hexane), which forms insoluable 1:2 adducts. In all cases, except that of silicon tetrahalide-pyridine complexes, heats of formation decreased in the order F>Cl>Br. This suggests that the order of acceptor power is SiF4>SiCl4>SiBr4 toward isoquinoline, and GeF4>GeCl4>GeBr4 toward pyridine and isoquinoline, assuming that lattice energies are similar in a series of related complexes having the same structure. Heats of formation of silicon tetrahalide-pyridine complexes, therefore, do not permit a true evaluation of relative acceptor properties. In the absence of structural differences it is evident that heats of formation of germanium tetrahalide adducts are greater than those of the corresponding silicon complexes. This confirms that germanium tetrahalides are stronger electron-pair acceptors than their silicon analogues.

Descriptors :   (*COMPLEX COMPOUNDS, *HEAT OF FORMATION), (*SILICON COMPOUNDS, COMPLEX COMPOUNDS), (*GERMANIUM COMPOUNDS, COMPLEX COMPOUNDS), HALIDES, ORGANIC SOLVENTS, PYRIDINES, QUINOLINES, CALORIMETRY, CHEMICAL REACTIONS, CANADA

Subject Categories : Inorganic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE