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

Abstract

The formate copper(I) complex [(P(C 6H 2CH 2NMe 2-2) 3)CuO 2CH] ( 3) is accessible by the reaction of equimolar amounts of P(C 6H 2CH 2NMe 2-2) 3 ( 1) with [CuO 2CH] ( 2). When 3 is treated with HO 2CH ( 4) or HO 2CMe ( 6), molecules [(P(C 6H 2CH 2NMe 2-2) 3)CuO 2CH · 2HO 2CH] ( 5) and [(P(C 6H 2CH 2NMe 2-2) 3)CuO 2CH · HO 2CMe] ( 7), respectively, are formed. In 3, 5, and 7 the phosphane unit is acting as a tripodal PN 2 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(C 6H 4CH 2NMe 2-2) 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 CuO 2CH entity, while the second HCO 2H molecule forms a N⋯H hydrogen bridge with the non-coordinating ortho-substituent Me 2NCH 2.