131063-80-4Relevant academic research and scientific papers
Octahedral and Trigonal-bipyramidal Complexes of Osmium(II) with 1,2-Bis(dicyclohexylphosphino)ethane. Stereochemistry of Addition Reactions to Five-co-ordinate Osmium(II) Derivatives and to Their Ruthenium(II) Analogues
Mezzetti, Antonio,Del Zotto, Alessandro,Rigo, Pierluigi
, p. 2515 - 2520 (1990)
The complexes cis- and trans- have been prepared, and their physical and chemical properties investigated.The cis isomers were found to dissociate quickly in polar solvents to give +, which have been isolated in the solid state as the tetraphenylborate salts.On basis of 31P n.m.r. and u.v.-visible spectra, the d6 cations are assigned a trigonal-bipyramidal structure with the halide in an equatorial position.The unsaturated complexes + readily and stereoselectively add halide or neutral ligands L (CO, MeCN, or PhCN) in dichloromethane solution to form the corresponding cis derivatives.The cis-+ cations can be thermally converted into the trans-isomers.The analogous + species, previously reported to give trans addition with X- and L, were found to form cis- and cis-+ at -60 deg C in dichloromethane or acetone solution.Also these species are thermally converted into the thermodynamically stable trans isomers.The complexes cis- were isolated, and the stereochemistry of the various six-co-ordinate complexes of osmium(II) and ruthenium(II) established by 31P n.m.r. and i.r. spectroscopy.The cis-trans interconversion of these osmium(II) and ruthenium(II) isomeric pairs in various solvents was also examined.
