Original scientific paper

The Full Non-Rigid Group Theory for cis- and trans-Dichlorodiammine Platinum(II) and Trimethylamine

Masood Hamadanian ; Department of Chemistry, Faculty of Science, University of Kashan, Kashan, Iran
Ali Reza Ashrafi ; Department of Mathematics, Faculty of Science, University of Kashan, Kashan, Iran

Abstract

The non-rigid molecule group theory (NRG), in which the dynamical symmetry operations are defined as physical operations, is a new field of chemistry. In a series of papers Smeyers applied this notion to determine the character table of restricted NRG (r-NRG) of some molecules. For example, Smeyers and Villa computed the r-NRG of the triple equivalent methyl rotation in pyramidal trimethylamine with inversion and proved that the r-NRG of this molecule is a group of order 648, containing two subgroups of order 324 without inversions (see J. Math. Chem. 28 (2000) 377–388). In this work, a simple method is described, by means of which it is possible to calculate character tables for the symmetry group of molecules consisting of a number of AH₃ groups attached to a rigid framework. We have studied the full non-rigid group (f-NRG) of cis- and trans-dichlorodiammine platinum(II) and trimethylamine and we have proven that they are groups of orders 36, 72 and 1296 with 9, 18 and 28 conjugacy classes, respectively. This shows that the full non-rigid group and the restricted non-rigid group of these molecules are not isomorphic. The method can be generalized to apply to other non-rigid molecules. The f-NRG molecule group theory is shown to be used advantageously to study the internal dynamics of such molecules.

Keywords

character table; full non-rigid group; cis-dichlorodiammine platinum(II); trans-dichlorodiammine platinum(II); trimethylamine

Hrčak ID:

103192

URI

https://hrcak.srce.hr/103192

Publication date:

28.11.2003.

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