Phosphinidene Transition Metal Complexes: A Combined Ab Initio MO-DFT Study of Cr(CO)5–PR

Autor: Luc G. Vanquickenborne, Minh Tho Nguyen, Steven Creve, Kristine Pierloot
Rok vydání: 1999
Předmět:
Zdroj: European Journal of Inorganic Chemistry. 1999:107-115
ISSN: 1099-0682
1434-1948
DOI: 10.1002/(sici)1099-0682(199901)1999:1<107::aid-ejic107>3.0.co;2-4
Popis: Ab initio MO and DFT calculations have been performed on phosphinidene complexes of the type Cr(CO)5–PR, with R = H, CH3, SiH3, NH2, PH2, OH, and SH. The formation of the Cr–P bond essentially arises from a ligand-to-metal charge transfer. While a significant π backdonation is also observed for the Cr(CO)5–PH, Cr(CO)5–PCH3, and Cr(CO)5–PSiH3 complexes, this is less the case for Cr(CO)5–POH, Cr(CO)5–PSH, and Cr(CO)5–PNH2, and the backbonding almost disappears for Cr(CO)5–PPH2. In both the lowest lying singlet and triplet states, all complexes exhibit a staggered conformation. CASSCF/CASPT2 calculations performed with the ANO basis sets indicate a closed-shell singlet ground state along the whole series. The binding energy between Cr(CO)5 and PR ranges from 216 kJ/mol for Cr(CO)5–PNH2 to 127 kJ/mol for Cr(CO)5–PSiH3 (B3LYP values). In general, the B3LYP-DFT scheme yields reasonable qualitative and quantitative results when compared with CASPT2(12/12).
Databáze: OpenAIRE
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