A DFT investigation on the electronic properties of octahaloditechnetate anions: Correlation between charge and bond strength

作者：Pastor Michael B; Zhao Qinliang^*

来源：Inorganica Chimica Acta, 2015, 424: 308-315.

DOI：10.1016/j.ica.2014.09.022

• Octahalodimetalate anions
• Multiple metal-metal bonds
• Bond order
• Bond length
• DFT calculations
• NBO analyses

Density functional theory (DFT) calculations using BH&HLYP, B3LYP, OPBE, SVWN, BP86, BLYP, HCTH, O3LYP, X3LYP, TPSS, OLYP, PBE, and TPSSh functionals with a variety of basis sets were conducted on octahalodimetalate anions M2X8n (M = Tc, Re, Mo; X = Cl, Br; n = 2-4). The purpose of the study was to investigate the abnormal Tc2X8n , system, where the Tc-Tc bond length unexpectedly shortened from Tc2X82 to Tc2X83, as the decrease in formal bond order from 4 to 3.5 normally tends to result in an increased bond length. Geometry optimizations using the functional BH&HLYP and basis sets SDD/aug-CC-PVDZ were able to reproduce this irregular change in Tc-Tc bond length. Natural bond orbital (NBO) analyses demonstrated that an increase in both sigma and pi bond strength, likely induced by the change in charge on the Tc atoms, resulted in the shortening in the Tc-Tc bond length. This study also suggested that DFT calculations on compounds with metal-metal bonds are sensitive to the choice of functionals and basis sets.

• 出版日期2015-1-1