Syntheses of tetrakis(Triarylarsineoxide)cobalt(II) Complexes by Solution Decomposition of Tetrakis(Alkylisocyanide)bis(triarylarsine)cobalt(II)

Abstract

Decomposition of the [Co(CNC₆H₁₁)₄(AsR₃)₂]X₂ complexes, where R = Ph, C₆H₄Me-p, X = CIO₄, BF₄, leads to [Co(OAsR₃)₄]X₂ complexes. Decomposition of [Co(CNC₆H₁₁)₄(AsPh₃)₂](CIO₄)₂ in CH₂Cl₂ solution to [Co(OAsPh₃)₄](CIO₄)₂ was observed under UV (254 nm) and visible (365 nm) irradiation, and in the dark; reaction time was shortest for irradiation under visible light. Decomposition of [Co(CNC₆H₁₁)₄(As(C₆H₄Me-p)₃)₂](CIO₄)₂ in CH₂Cl₂ solution under visible (365 nm) irradiation produced [Co(OAs(C₆H₄Me-p)₃)₄](CIO₄)₂, while [Co(CNC₆H₁₁)₄(AsPh₃)₂](BF₄)₂ slowly decomposed in the solid state so that simple recrystallization from CH₂Cl₂/ether produced [Co(OAsPh₃)₄](BF₄)₂. Characterization of the [Co(OAsR₃)₄]X₂ complexes in solid and solution states by magnetic susceptibility, v(As=O) IR, diffuse reflectance electronic spectra, and by molar conductivities, electronic spectra, indicates tetrahedral coordination.