Predicting bond dissociation energies and bond lengths of coordinatively unsaturated vanadium-ligand bonds

• Verfasst von: Bao, Junwei [VerfasserIn]
• Verfasst von: Welch, Bradley K. [VerfasserIn]
• Verfasst von: Ulusoy, Inga [VerfasserIn]
• Verfasst von: Zhang, Xin [VerfasserIn]
• Verfasst von: Xu, Xuefei [VerfasserIn]
• Verfasst von: Wilson, Angela K. [VerfasserIn]
• Verfasst von: Truhlar, Donald G. [VerfasserIn]
• Titel: Predicting bond dissociation energies and bond lengths of coordinatively unsaturated vanadium-ligand bonds
• Verf.angabe: Junwei Lucas Bao, Bradley K. Welch, Inga S. Ulusoy, Xin Zhang, Xuefei Xu, Angela K. Wilson, and Donald G. Truhlar
• E-Jahr: 2020
• Jahr: November 12, 2020
• Umfang: 14 S.
• Fussnoten: Gesehen am 18.04.2022
• Titel Quelle: Enthalten in: The journal of physical chemistry <Washington, DC> / A
• Ort Quelle: Washington, DC : Soc., 1997
• Jahr Quelle: 2020
• Band/Heft Quelle: 124(2020), 47, Seite 9757-9770
• ISSN Quelle: 1520-5215
• DOI: doi:10.1021/acs.jpca.0c06519
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1799710904

Abstract

Understanding the electronic structure of coordinatively unsaturated transition-metal compounds and predicting their physical properties are of great importance for catalyst design. Bond dissociation energy De and bond length re are two of the fundamental quantities for which good predictions are important for a successful design strategy. In the present work, recent experimentally measured bond energies and bond lengths of VX diatomic molecules (X = C, N, S) are used as a gauge to consider the utility of a number of electronic structure methods. Single-reference methods are one focus because of their efficiency and utility in practical calculations, and multireference configuration interaction (MRCISD) methods and a composite coupled cluster (CCC) method are a second focus because of their potential high accuracy. The comparison is especially challenging because of the large multireference M diagnostics of these molecules, in the range 0.15-0.19. For the single-reference methods, Kohn-Sham density functional theory (KS-DFT) has been tested with a variety of approximate exchange-correlation functionals. Of these, MOHLYP provides the bond dissociation energies in best agreement with experiments, and BLYP provides the bond lengths that are in best agreement with experiments; but by requiring good performance for both the De and re of the vanadium compounds, MOHLYP, MN12-L, MGGA_MS1, MGGA_MS0, O3LYP, and M06-L are the most highly recommended functionals. The CCC calculations include up to connected pentuple excitations for the valence electrons and up to connected quadruple excitations for the core-valence terms; this results in highly accurate dissociation energies and good bond lengths. Averaged over the three molecules, the mean unsigned deviation of CCC bond energies from experimental ones is only 0.4 kcal/mol, demonstrating excellent convergence of theory and experiments.