Anisotropic Polarizabilities of Tin(IV)-Containing Groups

1986 ◽  
Vol 39 (2) ◽  
pp. 221 ◽  
Author(s):  
GW Allen ◽  
RS Armstrong ◽  
MJ Aroney ◽  
RK Pierens ◽  
KR Skamp
Keyword(s):  
Raman Band ◽  
Dipole Moments ◽  
Organotin Compounds ◽  
Molecular Polarizability ◽  
Optical Scheme ◽  
Group Polarizability

Electric birefringences , dipole moments and refractivities are reported for a series of organotin compounds. From these are deduced molecular polarizability anisotropies which, with data from Raman band intensities, can be dissected to give the anisotropic polarizabilities for component tin-containing groups. The results fit reasonably within a 'valence-optical' scheme of group polarizability additivity. Regular trends are observed in the directional polarizabilities of groups containing the Group 4b elements Si, Ge and Sn.

High Pressure Raman Study of the Hydrolysis Reaction of Tmos and Teos

1990 ◽  
Vol 180 ◽  
Author(s):  
G. Hoang ◽  
J. Watson ◽  
T. W. Zerda
Keyword(s):  
Raman Spectroscopy ◽  
Dielectric Constant ◽  
High Pressure ◽  
Hydrogen Bonding ◽  
Raman Band ◽  
Dipole Moments ◽  
Hydrolysis Reaction ◽  
Or Groups ◽  
Bonding Properties ◽  
Raman Study

ABSTRACTHigh pressure Raman spectroscopy is used to monitor the hydrolysis reaction of TMOS in solutions with methanol, acetonitrile, acetone, dioxane and formamide, and of TEOS as a function of pH and the catalyst used. The rate constants for various solvents, temperatures and pressures are experimentally determined from the time dependence of Raman band intensities. It is shown that the reaction is slow in dioxane and fast in methanol or formamide. The volume of activation is found from the pressure dependence of the rate constant. The volume of activation, the dielectric constant, dipole moments and hydrogen bonding properties and their role in the hydrolysis reaction are discussed. It is shown that solvents which can form hydrogen bonding with Si-OR groups can increase the rate of the reaction.

Molecular polarizability: Symmetrically substituted mesitylenes

1968 ◽  
Vol 21 (2) ◽  
pp. 275
Author(s):  
KE Calderbank ◽  
RJW Le Fevre ◽  
RK Pierens ◽  
DV Radford
Keyword(s):  
Carbon Tetrachloride ◽  
Microwave Absorption ◽  
Dipole Moments ◽  
Molecular Polarizability ◽  
Atomic Polarization ◽  
Kerr Constants ◽  
Absorption Measurements

Molar Kerr constants ( x 10-12) are reported for 2,4,6-trichloromesitylene, 2,4,6.tribromomesitylene, and 2,4,6-triiodomesitylene as solutes in carbon tetrachloride and for 2,4,6-trinitromesitylene as a solute in benzene. Microwave absorption measurements indicate the non-polarity of all four solutes and the small apparent dipole moments observed for some of these solutes can be ascribed to atomic polarization. The substituents are not therefore staggered as has previously been suggested for 2,4,6-trinitromesitylene. Estimates of the polarizability semi-axes for these molecules are given.

Molecular polarizability. The dipole moments, molar Kerr constants, and conformations of some chloroformic esters

1969 ◽  
Vol 22 (8) ◽  
pp. 1599 ◽  
Author(s):  
MJ Aroney ◽  
FFvre RJW Le ◽  
RK Pierens ◽  
HLK The
Keyword(s):  
Experimental Data ◽  
Carbon Tetrachloride ◽  
Dipole Moments ◽  
Molecular Polarizability ◽  
Methyl Ethyl ◽  
Conformational Preferences ◽  
Kerr Constants

Dipole moments and molar Kerr constants are reported for methyl, ethyl, and phenyl chloroformates in carbon tetrachloride and in benzene. The experimental data are analysed to provide information on the conformational preferences of the solutes in the ?inert? CCl4 environment and on solute-solvent associations in benzene.

Influence of geometry on positron binding to molecules

2021 ◽  
Author(s):  
J R Danielson ◽  
Soumen Ghosh ◽  
clifford surko
Keyword(s):  
Dipole Moment ◽  
Binding Energy ◽  
Positron Annihilation ◽  
Significant Role ◽  
Dipole Moments ◽  
Molecular Size ◽  
Molecular Geometry ◽  
Binding Energies ◽  
Molecular Polarizability ◽  
Global Parameters

Abstract Annihilation studies have established that positrons bind to most molecules. They also provide measurements of the positron-molecule binding energies, which are found to vary widely and depend upon molecular size and composition. Trends of binding energy with global parameters such as molecular polarizability and dipole moment have been discussed previously. In this paper, the dependence of binding energy on molecular geometry is investigated by studying resonant positron annihilation on selected pairs of isomers. It is found that molecular geometry can play a significant role in determining the binding energies even for isomers with very similar polarizabilities and dipole moments. The possible origins of this dependence are discussed.

Molecular polarizability. The dipole moments, molar Kerr constants, and conformations of some dialkyl and diaryl disulphides

1968 ◽  
Vol 21 (2) ◽  
pp. 281 ◽  
Author(s):  
MJ Aroney ◽  
RJW Le Fevre ◽  
. Pierens.R.K ◽  
HLK The
Keyword(s):  
Experimental Data ◽  
Carbon Tetrachloride ◽  
Dipole Moments ◽  
Molecular Polarizability ◽  
Dihedral Angles ◽  
Aryl Group ◽  
Carbon Tetrachloride Solution ◽  
Dimethyl Disulphide ◽  
Kerr Constants

Dipole moments and molar Kerr constants are reported for five organic disulphides R2S2 (where R is methyl, t-butyl, phenyl, p-chlorophenyl, and β-naphthyl)in carbon tetrachloride solution. The experimental data are analysed to show (a) that each molecule has a skew structure with dihedral angles in the range 88-85� between the planes C?-S-S and S-S-C"; (b) that the anisotropic electron polarizabilities of the S-S group in dimethyl disulphide are bL = 4.66 �3, bT = bv = 2.25 �3; and (c) that in the aromatic disulphides the aryl group planes are nearly coplanar with their respective Car-S-S groups.

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