Organometallic analogs of the cyclobutadiene dication: an ab initio MO and density functional study of the symmetrical planar and puckered [WL₂(μ-CR)]₂ complexes (L = H, Me, F, OH; R = H, F, Me)

Abstract

Ab initio MO and density functional theory calculations are reported for tungsten complexes [WL₂(μ-CR)]₂ (L = H, Me, F, OH; R = H, F, Me). The general perception that these complexes are always planar is contradicted. The effect of ligand L and substituent R on the puckering of four-membered W₂C₂ ring are studied. With L = H, the ring puckering is in the order of R = F < H < Me. With R = H, the ring puckering is in the order of L = OH ≈ F < Me < H. The puckering of W₂C₂ ring depends more on the ligand L than on the substituent R. The analogous nature of these complexes to cyclobutadiene dications is also discussed.