Phosphane copper(I) formate complexes stabilized by formic acid and acetic acid through H⋯O⋯H bridges

The formate copper(I) complex [(P(C6H2CH2NMe2-2)3)CuO2CH] (3) is accessible by the reaction of equimolar amounts of P(C6H2CH2NMe2-2)3 (1) with [CuO2CH] (2). When 3 is treated with HO2CH (4) or HO2CMe (6), molecules [(P(C6H2CH2NMe2-2)3)CuO2CH · 2HO2CH] (5) and [(P(C6H2CH2NMe2-2)3)CuO2CH · HO2CMe] (7), respectively, are formed.In 3, 5, and 7 the phosphane unit is acting as a tripodal PN2 ligand as it could be shown by 1H NMR spectroscopy. IR studies showed that the formate building block in 3 and in its solvated form in 5 and 7 is σ-bonded by one oxygen atom to Cu(I). The thermal decomposition behavior of 3 is discussed.The solid state structure of 5 is reported. The crystal structure consists of two chemical identical crystallographic independent molecules. In 5 a four-coordinated copper(I) ion is present with the P(C6H4CH2NMe2-2)3 ligand occupying three of the coordination sites, while the 4th site is occupied by the formate anion. One of the two formic acid molecules in 5 is thereby hydrogen-bonded to the CuO2CH entity, while the second HCO2H molecule forms a N⋯H hydrogen bridge with the non-coordinating ortho-substituent Me2NCH2.

The synthesis of the phosphane copper(I) formate [(P(C6H4CH2NMe2-2)3)CuO2CH] and its reaction chemistry toward formic and acetic acid is described. The solid state structure of [(P(C6H4CH2NMe2-2)3)CuO2CH · 2HCO2H] is reported as well.Figure optionsDownload as PowerPoint slide