Recently, the molecular structures of a relatively large number of
sulphone compounds have been elucidated in the vapour phase by electron
diffraction and microwave spectroscopy. The main purpose of these
studies is the determination of the sulphur bond configuration and the
conformational properties. This leads to the observation and correlation
of characteristic structural variations as various ligands are attached
to the S02 group and as comparisons are made with related molecules.
Today it may be said that the structure of sulphone molecules is
relatively well studied, and it appeared necessary to systematize the
accumulated experimental data after critical considerations. This is
done in the first part of this monograph. The second part presents the
observed characteristic structural variations. Attempts are made to
interpret these variations by valence shell electron pair repulsions
and-non-bonded interactions. Correlation relationships between geometric
and vibrational parameters are also presented. It is the metrical
aspects of the molecular structure which are primarily considered. Since
they correlate with other aspects of the molecular structure, e.g.
electronic, it is hoped that the experimental information on the
molecular geometry provides stim- ulus for further experimental, and, in
particular, theoretical work on sulphones and related systems. IV It is
attempted to cover all electron diffraction and micro- wave
spectroscopic investigations on sulphone molecules to date. Admittedly,
however, relatively larger weight is given to the electron diffraction
studies originating from the author's own laboratory.