ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 6, pp. 967! 974. + Pleiades Publishing, Inc., 2006.
Original Russian Text + Yu.E. Zevatskii, S.S. Lysova, 2006, published in Zhurnal Prikladnoi Khimii, 2006, Vol. 79, No. 6, pp. 978 ! 985.
AND INDUSTRIAL ORGANIC CHEMISTRY
Relationship between the Molar Volume and Enthalpy
of Formation, Polarizability, and Ionization Potential
of CHNO-containing Organic Substances
Yu. E. Zevatskii and S. S. Lysova
St. Petersburg State Technological Institute, St. Petersburg, Russia
Received March 1, 2006
Abstract-A new approach to revealing a relationship between various physicochemical properties of organic
compounds is suggested. The basic principle of this approach consists in that deviations of experimental
values of various molecular parameters from linear dependences for the constituent elements are due to
intramolecular forces of the same nature.
The precision achieved in calculation of physico-
chemical parameters of substances still remains a key
issue in chemistry and physics. Despite the existence
of a wide variety of additive methods, which make it
possible to calculate with a small error the properties
of molecules with various structures, their number
continues to grow. The general principle of the known
calculation procedures is that the value of a property
(enthalpy of formation, polarizability, volume of a
molecule, etc.) is regarded, in accordance with the ad-
ditivity rule, as a sum of partial properties of separate
fragments of the molecule. Atoms, chemical bonds,
functional groups, etc. can be chosen as fragments
of this kind.
In calculating the density of substances, the molar
volume is determined on the basis of the molecular
elements suggested by Stine , by the Cady method
 with the use of Van der Waals radii; in addition,
procedures with certain refinements and corrections
were reported in .
The additive methods for calculation of the enthal-
py of formation of substances can be divided into
three groups . The first of these is based on the ad-
ditivity principle for bond energies, developed by
Pauling, Tatevskii, Leidler, and others. The second
group employs dependences of the thermochemical
properties of substances on other thermodynamic pa-
rameters (methods of Karas and Handrick). To the
third group belong methods based on the principle of
additivity of the thermochemical properties of various
structural groups contained in a molecule (reports by
Esterman and Raikova).
Modern methods for calculation of the polarizabil-
ity of molecules were described in [8, 9]. The review
 is devoted to a critical analysis of experimental
and calculated data on the static polarizability of more
than 650 molecules of various classes of substances.
In , the previously suggested  empirical meth-
od for calculation of the molecular polarizability from
parameters of [atomic hybrids] was further developed.
The results obtained in calculation of the mean po-
larizability, anisotropy, and principal components of
the polarizability were compared with calculations
based on the polarizability of bonds  and groups
, and the possibility of passing from the [hybrid
parameters] suggested by the authors to other empir-
ical parameters was demonstrated.
The methods for calculation of the ionization po-
tentials of molecules are based on the generalized
Koopmans’ theorem in the form of certain approx-
imations . The effect of substituents is taken into
account using the principle of linearity of free ener-
gies, with a distinction made between the inductive,
resonance, and polarization effects linearly appear-
ing in the expression for the ionization potentials
[15, 16]. Dependences of the ionization potentials
on linear dimensions have been obtained only for
atoms, with attempts to establish a relationship of
this kind for nonpolar molecules undertaken only