The molecular structure of methane sulfonyl chloride in the vapors was studied by electron diffraction. Three models were found in excellent agreement with experiment differing largely in the values of the O–S–O angle and the mean amplitudes of vibration for some of the nonbonded distances. The favored model has the following geometrical parameters (with their errors parenthesized): C–H 1.101 (0.013) A, S–O 1.424 (0.003) A, S–C 1.763 (0.005) A, Cl–S 2.046 (0.004) A, ∠ Cl–S–C 101.0° (1.5°), ∠ O–S–O 120.8° (2.4°), ∠ Cl–S–O 107.1° (0.7°), ∠ H–C–H 112.0° (2.0°). The structure of SO2Cl2, CH3SO2Cl, and (CH3)2SO2 are compared.

On the molecular structure of methane sulfonyl chloride as studied by electron diffraction

An electron diffraction study of the molecular geometry of dimethyl sulphone

An electron diffraction study of the molecular structure of hexamethyldisiloxane

If an electron beam is crossed by a molecular jet, the electrons are scattered (Fig 1) At some distance from the scattering center (the nozzle, Fig 1) one can observe the scattering pattern, a system of concentric rings (Fig 2) These rings have varying intensities The intensity distribution is a function of the structure of the scattering molecules This is the basis of electron diffraction as a tool of structural chemistry

Electron Diffraction as a Tool of Structural Chemistry

The information assembled in this review of the gas phase molecular structures of fluorocarbons and related compounds were derived from electron diffraction patterns and microwave spectra. We placed primary emphasis on the geometrical effects of fluorine substitution (bond distances, bond angles and internal rotational parameters). Clearly other aspects of molecular structure, such as dipole moments, average bond dissociation energies, photoelectron spectra, etc. merit codification. At first glance, interatomic distances and bond angles call attention to features which appear to be strictly localized within molecules. It is evident, however, that such a local bond concept is not consistent with the totality of structural data on the level of precision currently available. Furthermore, it is also clear that the level of accuracy now generally attainable in the computation of molecular geometries is considerably below experimentally derived quantities. Regularities in the molecular structures of organic fluorides have been uncovered. For some structural types there are strong similarities and comparable trends among the fluorides of elements other than carbon. The substitution or environmental effects on molecular structures raise interesting questions regarding the nature of chemical bonds, and the contrasts between fluorine and hydrogen substituents provide an incisive focal points for theoreticians.

Istva´n Hargittai

Papers

Electron diffraction study on the molecular structure of methane sulphonyl fluoride