Further studies of the substitution reactions of bis(tetracarbonylcobaltio)mercury with phosphorus(III) and arsenic(III) ligands

Abstract

The reactions of {Co(CO)₄}₂Hg with various phosphorus(III) ligands in the absence of light give {LCo(CO)₃}₂Hg and, under more vigorous conditions, {L₂Co(CO)₂}₂Hg derivatives [L = Et₃P, Bu_nⁿP, PhMe₂P, Ph(Prⁱ)₂P, Ph₂MeP, (Et₂N)₃P, Ph₂POMe, PhP(OMe)₂, (MeO)₃P, (2-ClC₂H₄O)₃P, PhOP(OCH₂)₂ or (PhO)₃P]. The bidentate ligand Ph₂PCH₂CH₂PPh₂, dp yields (dp)Co₂(CO)₆Hg and {(dp)Co(CO)₂}₂Hg. Analogous arsenic complexes are also decribed. Some reactions of these two compounds with mercury(II) halides or tin(IV) chloride have been investigated. The complex {(dp)Co(CO)₂}₂Hg yields (dp)Co(CO)₂X (X = HgCl, HgBr, Hgl, or SnCl₃) and {(da)Co(Co)₂}₂Hg reacts similary, but whereas (Ph₂PCH₂)₂Co₂(CO)₆Hg gives a mixture of (Ph₂PCH₂)₂-Co(CO)₂X and Co(CO)₄X, (Ph₂AsCH₂)₂Co₂(CO)₆Hg gives only (Ph₂AsCH₂)₂{Co(CO)₃X}₂. The i.r. spectra of all compounds in the 1700–2100 cm^–1 region are reported, absorption bands due to v(CO) vibrations are identified, and structures proposed for the new derivatives.