CCl4: mean dipole moment derivatives and core electron binding energies

Atomic polar tensors for the carbon tetrachloride molecule are calculated f rom experimental fundamental infrared intensities, a normal coordinate tran sformation determined from observed fundamental frequency values and experi mentally determined CCl bond lengths. Dipole moment derivative sign ambigui ties were eliminated by comparing the alternative mathematical solutions ob tained from the experimental data with results of Hartree-Fock, Moller-Ples set 2 and Density Functional Theory calculations using a 6 -31 + + G(d,p) b asis set. Carbon and chlorine mean dipole moment derivatives of 1.043 +/- 0 .022e and - 0.261 +/- 0.006e, respectively, are determined from the preferr ed atomic polar tensors. These values are in excellent agreement with those obtained from the CCl4 Is carbon atom ionization energy using a simple pot ential model (1.081e and - 0.270e), from an electronegativity model propose d earlier (1.008e and - 0.252e) and from an electronegativity equalization model (1.066e and - 0.266e). (C) 1999 Elsevier Science B.V. AU rights reser ved.