Direct calculation of CO-factored force constants from (CO)-C-12-O-16 stretching frequencies in LM(CO)(4) molecules with C-3 nu symmetry

Abstract

The CO-factored force constants for LM(CO)(4) molecules having C-3v symmetry were calculated using the relations k(1) = alpha(3 lambda(1) + lambda(2) + 8 lambda(3)), k(2) = 3 alpha(lambda(1) + 3 lambda(2)), k(c)= 3 alpha(lambda(1) - lambda(2)) and k(c)(i) = alpha(3 lambda(1) + lambda(2) - 4 lambda(3)) where alpha = 1/(12 mu). The force constants obtained in this way were compared with those determined by the cos beta parameter method and isotopic substitution. This comparison led us to conclude that the mentioned relations which allow direct calculation of force constants from C-O stretching frequencies of the all-(CO)-C-12-O-16 molecule work very well for the complexes under study. (C) 1999 Elsevier Science S.A. All rights reserved.