Rafał Wysokiński

The performance of different density functional methods in the calculation of molecular structures and vibrational spectra of platinum(II) antitumor drugs: cisplatin and carboplatin

A comparison of eight density functional models for predicting the molecular structures, vibrational frequencies, infrared intensities, and Raman scattering activities of platinum(II) antitumor drugs, cisplatin and carboplatin, is reported. Methods examined include the pure density functional protocols (G96LYP, G96PW91, modified mPWPW and original PW91PW91), one‐parameter hybrid approaches (mPW1PW and mPW1LYP), and three‐parameter hybrid models (B3LYP and B3PW91), as well as the HF and MP2 levels of theory. Different effective core potentials (ECPs) and several basis sets are considered. The theoretical results are discussed and compared with the experimental data. It is remarkable that the mPW1PW protocol introduced by Adamo and Barone [J Chem Phys 1998, 108, 664], is clearly superior to all the remaining density functional methods (including B3LYP). The geometry and vibrational frequencies of cisplatin and carboplatin calculated with the mPW1PW method, and the ECP of Hay and Wadt (LanL2DZ basis set) are in better agreement with experiment than those obtained with the MP2 method. The use of more elaborated ECP and the enlargements of basis sets do not significantly improve the results. A clear‐cut assignments of the platinum‐ligand vibrations in cisplatin and carboplatin are presented. It is concluded that mPW1PW is the new reliable method, which can be used in predicting molecular structures and vibrational spectra of large coordination compounds containing platinum(II).

Density functional and ab initio studies of the molecular structures and vibrational spectra of metal triiodides, MI3 (M=As, Sb, Bi)

Abstract The molecular structures, harmonic frequencies, absolute infrared intensities and Raman scattering activities have been calculated for metal triiodides, MI3 (M=As, Sb, Bi) with the use of hybrid density functional (mPW1PW and B3LYP) and ab initio (HF and MP2) methods. The theoretical results are compared with the available experimental data and other ab initio calculations reported earlier. It is demonstrated that the density functional approach of Adamo and Barone, mPW1PW, [J. Chem. Phys. 108 (1990) 664] is superior to B3LYP and ab initio methods in predicting molecular structures and vibrational spectra of metal iodides.