The electronic structure of the phosphathoracyclobutane [formula omitted] complex (Cp′ = η5-Me5C5) has been investigated by a combination of ab initio relativistic effective core potential calculations for geometry optimization, DV-Xα calculations, and UV photoelectron spectroscopy. The formation of the four-membered ring involves bonding interactions analogous to those found in cyclobutane. Metalligand bonding involves both 5f and 6d metal atomic orbitals with a major role of the latter. The gas-phase UV photoelectron spectrum has been assigned using both comparative arguments and TSIE values obtained from DV-Xα calculations, as well as PE data on the closely related [formula omitted] complex. The optimized structure is indicative of a slightly puckered four-membered metallacyclic ring having the P-CH3 vector in an endocyclic axial orientation. The structure shows close analogies with diffraction data for the related [formula omitted] complex. According with NMR data, a single energy minimum has been found for the conformation with smaller intraligand repulsive interactions involving the P3p lone pair.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry