THEORETICAL-STUDY OF TRANSITION-ELEMENT CARBONYLS MCO AND CARBENES MCH2 (M=TI, FE, NI) IN THE GROUND AND FIRST ELECTRONIC EXCITED-STATES BYDFT METHODS

The electronic structure and properties of the carbonyls TiCO, FeCO, a nd NiCO in the quintuplet, triple;, and singlet ground states and trip ler, quintuplet, and triplet first electronic excited states, respecti vely, were studied using density functional theory (DFT) methods. The ADF program (version 2.1) with the parameterizations BP86, BPW91, and BLYP (for the GGA corrections) and the Slater-type orbital (STO) basis sets TV as well as the GAUSSIAN 94 program with the parameterizations BP86, PW91, BLYP, B3PW91, and B3LYP and the Gaussian basis sets 6-311 G(d, p) were used. Similar calculations were done on the carbenes TiCH 2, FeCH2, and NiCH2 in the triplet, triplet, and singlet ground electr onic states and the quintuplet, quintuplet, and triplet first electron ic excited states. Geometry optimization and the calculation of dissoc iation energies for the M-C bond, vibrational frequencies, electric at omic charges, and dipole moments were performed for these compounds in the above-mentioned states, and comparisons between the results obtai ned as well as with those reported in the literature were made. (C) 19 98 John Wiley & Sons. Inc.