Copper(I) carboxylates: preparations and infrared and mass spectral features

Abstract

Procedures for the high-yield preparations of a range of copper(I) carboxylates, CuO₂CR (R = H, Me, CH₂Cl, CHCl₂, CF₃, CH₂CN, CH₂SH, Et, Prⁿ, Ph, o-NO₂·C₆H₄, CHCHPh, and CHCH·CO₂H) are reported. The i.r. spectra of these compounds are briefly discussed. The mass spectra of a selection of the copper(I) carboxylates show the presence of dimeric ions in high abundance in the vapour, together with very low abundances of trimeric and tetrameric ions. The alkanecarboxylates initially lose RCO₂˙ from the radical ion Cu₂(O₂CR)₂^+˙, whereas the arenecarboxylates also easily lose CO₂ from this radical ion leading to the formation of many ions containing Cu–C bonds. The monochloroacetate and o-nitrobenzoate also fragment to give ions possessing Cu–Cl and Cu–NO₂ bonds respectively.