Matrix Infrared Spectra of FB≡WF2 and F2BMF (M = Cr, Mo and W) Complexes and Quantum Chemistry Calculations
Laser-ablated group 6 transition metal atoms react with BF3 to yield terminal borylene complex FB≡WF2 and typical transition metal inserted complexes F2B-MF (M=Cr, Mo, W). These products are investigated by Infrared spectra, isotopic substitution and theoretical frequency calculations. The FB≡WF2 molecule has 11B-F (10B-F) stretching frequency at 1453.2 (1505.0) cm-1 and the triple bond between boron and tungsten is confirmed by EDA-NOCV calculations, active molecular orbital and NBO analysis. The inserted complexes F2B−MF (M= Cr, Mo, and W) were identified by asymmetric and symmetric stretching modes of F-B-F. Furthermore, the bonding for tungsten complexes are compared with that of molybdenum and chromium complexes, which reveals interesting difference in their chemistries.