Electronic structure and spectroscopic properties of electronic states of VC2, VC2−, and VC2+

Abstract

Articles you may be interested inAn all-electron density functional theory study of the structure and properties of the neutral and singly charged M 12 and M 13 clusters: M = Sc-Zn Geometry and electronic structure of V n ( Bz ) m complexes Theoretical studies on the electronic and thermodynamic properties of several electronic states are presented for the VC 2 molecule, the VC 2 Ϫ anion, and the VC 2 ϩ cation employing state-of-the-art techniques that included up to 12 million configurations. The ground and the low-lying electronic states of these three species have been found to have C 2v triangular structures. On the basis of our computed results, we have suggested an assignment of the observed anion photodetachment spectra of VC 2Ϫ and predicted transitions that were not observed. Our computed electron affinity is in excellent agreement with experiment. The observed thermodynamic properties of reactions involving VC 2 , VC 2 Ϫ , and VC 2 ϩ are corrected using the computed gas phase properties of the molecule and the partition functions. The bent quartet states of VC 2 exhibit large dipole moments (8.65Ϫ9.3 D). d is the dipole moment in Debye. The positive value means V ϩ C Ϫ polarity of bonds and the dipole vector bisects the C-V-C apex angle for the isosceles triangle. For the linear structure it is along the molecular axis. 132

Structure and Bonding in First‐Row Transition‐Metal Dicarbides: Are They Related to the Stability of Met‐cars?

“…For the FeC 2 system we found a 5 A 2 (⋅⋅⋅9a 1 2 1a 2 2 5b 2 1 10a 1 1 4b 1 1 11a 1 1 ) electronic lowest‐lying state at the B3LYP, QCISD, and CCSD(T) levels of theory, whereas a previous study23 predicted a 5 A 1 (⋅⋅⋅9a 1 2 1a 2 1 5b 2 1 10a 1 2 4b 1 1 11a 1 1 ) ground state at the CASPT2 level with the 5 A 2 state lying just 1.43 kcal mol −1 higher in energy. Linear VC 2 was predicted to have a sextet lowest‐lying state in a previous study,20 whereas in our calculations the quartet is slightly lower in energy. In any case, we have adopted the quartet state because it correlates with the cyclic ground state.…”

Structural Evolution and Electronic Properties of VnC20/– and VnC40/– (n = 1–6) Clusters: Insights from Photoelectron Spectroscopy and Theoretical Calculations

“…Redondo et al studied VC n 0/± ( n = 2–8) clusters using density functional theory (DFT) calculations , and found a clear even–odd alternation in the stability of the fan-like structures of VC n 0/+ ( n = 2–8). The electronic states of the ground state VC 2 0/± structures are predicted to be 4 B 1 , 3 B 1 , and 5 B 1 at the DFT/B3LYP and CASSCF/MRSDCI levels . Studies of V 2 C 2 – using photoelectron spectroscopy and DFT have indicated that the ground state structure has a planar distorted four-membered ring geometry with a transannular V–C bonding .…”

“…The electronic states of the ground state VC 2 0/± structures are predicted to be 4 B 1 , 3 B 1 , and 5 B 1 at the DFT/ B3LYP and CASSCF/MRSDCI levels. 19 Studies of V 2 C 2 − using photoelectron spectroscopy and DFT have indicated that the ground state structure has a planar distorted four-membered ring geometry with a transannular V−C bonding. 20 The electronic and geometric structures of V 2 C n − (n = 2−4) have been studied using photoelectron spectroscopy and DFT calculations.…”

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“…A number of theoretical studies of heteroatom‐carbon clusters has been carried out, most of them dealing with XC n clusters in which the heteroatom belongs to a first‐ or second‐row element. In the case of the first‐row transition‐metal, monocarbides and dicarbides have been the subject of several theoretical studies 10–25. Dicarbides compounds have been found to prefer a C 2v ‐symmetry arrangement over a linear one.…”