Metal Complexes of Heteroarenes, X(1). #eta#~1-Coordination of Phosphinine: Synthesis and Structure of cis-Dichloro-bis (2, 6-dimethyl-4-phenyl-phosphinine) platinum

摘要

Cis-Dichloro-bis (2, 6-dimethyl-4-phenyl-#eta#~1-phosphinine) platinum (3) has been prepared by ligand substitution from cis-dichloro (2, 5-cyclooctadiene) platinum and characterized by spectroscopy (~1H, ~(13)C, ~(31)P NMR, IR, UV-Vis), CV and X-ray diffraction (space group P2_1/c, a = 14.998, b = 16.540, c = 11.506 A, #alpha# = #gamma# = 90 deg, #beta# = 92.46 deg, Z = 4), In line with findings for similar P hybridization states, the Pt-P bond length (221 pm) in 3 equals that in #eta#~1-phosphaalkene Pt complexes and falls short of the respective parameters in Pt phosphane species. The stretching frequencies #nu#_(PtCl) and the bond length Pt-Cl indicate that phosphinines and phosphaalkenes, relative to phosphanes, adopt a lower position on the trans-influence scale. This gradation is also suggested by the coupling constants ~1J (~(195)Pt, ~(31)P).