Electronic Structure and Bonding in Heteronuclear Dimers of V, Cr, Mo, and W: a CASSCF/CASPT2 Study

• Published in: Inorganic chemistry Vol. 50; no. 19; pp. 9219 - 9229
• Main Authors: Ruipérez, Fernando, Ugalde, Jesus M, Infante, Ivan
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 03.10.2011
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic200061h

Heteronuclear dimers like CrMo, CrW, MoW, VCr, VMo, VW, and their anions have been investigated by means of multiconfigurational quantum chemistry methods, using the complete active space self-consistent field followed by second-order perturbation theory, CASSCF/CASPT2. We explored in great detail several spectroscopic properties such as bond length, potential energy surfaces, dissociation energies, ionization potentials, electron affinities, low-lying excited states, vibrational frequencies, and dipole moments. All proposed dimers show ground states with a pronounced multireference character. The group VI heterodimers have a 1Σ+ ground state, while the mixed group V–group VI heterodimers show a 2Δ ground state. Among all dimers, only VCr presents a potential energy profile with a deep minimum in the d–d region and a shelf-like potential in the s–s region. All the remaining dimers show only the short-range minimum. The largest effective bond order is obtained for the MoW, with a value of 5.2, that is, a weak sextuple bond. Most of the obtained results are valuable tools to drive future experimental investigations.