Correlation of Rates of Intramolecular Tunneling Processes, with Application to Some Group V Compounds

A method is presented whereby the WKB expression for tunneling frequencies permits correlation of these frequencies for members of homologous series of molecules. The necessary data required are the tunneling rate for one member of the series, and structural parameters and vibrational frequencies for all members of interest. The method is applied to ND3, NF3, PH3, and AsH3, using NH3 as the molecule whose frequency is known. The method also is used to support the hypothesis that pseudorotation occurs in the trigonal bipyramids PF5 and PCl5.