Effect of structural features of molecules (Cl3PNZ)2 (Z = CH3 and CH2CH2Cl) on the position exchange of chlorine atoms in the P-Cl fragments

Based on the analysis of structural parameters of molecules (Cl3PNCH3)2 (I) and (Cl3PNCH2CH2Cl)2 (II) by the quantum-chemical nonempirical calculations the following was revealed. The structure of I and II dimers has geometric features, which have a decisive influence on the degree of inhibition of positional exchange of the chlorine atoms in the P-Cl fragments known for the chlorine derivatives of pentacoordinated phosphorus atom. The obstacles to this dynamic process in the mentioned intramolecular dimers is shown to result from the spatial nonvalent interactions due to the short contacts of the chlorine and hydrogen atoms.