EFFECTIVE BOND CHARGES FROM EXPERIMENTAL IR INTENSITIES

Experimental gas-phase IR absorption intensities for water, ammonia, methane, ethene, ethyne, propyne, methyl fluoride, methyl chloride, methyl bromide, methyl iodide, formaldehyde, F2CO, Cl2CO, F2CS and Cl2CS are transformed into quantities termed effective bond charges (delta(k)) following a recently developed formalism. The comparison of delta(k) values for eH, N-H, C-H, C-X (X = F, CI, Br, I), C = O and C=S bonds reveals trends of changes that can be associated with the valence state and electronegativities of constituent atoms and also with polarities and electronic polarizabilities of the respective bonds.