Crystal structure and chemical properties of [Cu(3,5Me 2-pz-C(S)-S)(CNR) 2] (R=cyclohexyl; 3,5Me 2-pz=3,5-dimethylpyrazolate)

Abstract

The binuclear copper(I) complex [Cu(3,5Me 2-pz)(CNR)] 2 (R=cyclohexyl; 3,5Me 2-pz=3,5-dimethylpyrazolate) ( A) reacts with CS 2 in the presence of free RNC, yielding the 3,5-dimethylpyrazole-carbodithioate derivative [Cu(3,5Me 2-pz-C(S)-S)(CNR) 2] ( I). In the absence of free RNC, A gives [Cu 2(3,5Me 2-pz-C(S)-S) 2(CNR)] ( II). The action of an excess of RNC on II afforded I. One RNC ligand in complex I is easily replaced by PPh 3 producing [Cu(3,5Me 2-pzC(S)-S)(CNR)(PPh 3)] ( III). The crystal and molecular structure of I has been elucidated by single crystal X-ray analysis. Its unit cell has dimensions a= b=9.806(1), c=23.734(6) Å, space group P4 1. The structure was solved with conventional Patterson and difference Fourier methods, and refined to R=0.040 for 1134 reflections having I>3σ( I). By treating I with ethyl bromide, the pyrazole carbodithioate anion is displaced and recovered as the corresponding ethyl ester, 3,5Me 2-pzCS 2Et.