Halide and substituent dependent structural variation in copper(i) halide complexes of 1,5,9-triphosphacyclododecanes

The reactions of 1,5,9-triethyl-1,5,9-triphosphacyclododecane, [12]-ane-P3Et3, and 1,5,9-tri(2-propyl)-1,5,9-triphosphacyclododecane, [12]-ane-P3iPr3 with copper(i)halides produce either bimetallic species of the type [([12]-ane-P3R3)Cu(CuX2)] (X = halide) or monomeric [([12]-ane-P3R3)CuX] depending on the nature of the halide and, to a lesser extent, the macrocycle. With CuCl only bimetallic complexes are formed with one copper centre bound to the macrocycle and a second attached through a Cu-Cu bond with a mono bridging chloride. CuBr affords monomeric [([12]-ane-P3R3)CuBr] complexes when performed in a 1 : 1 M : L ratio whereas the bimetallic compound [([12]-ane-P3Et3)(CuBr)2], resulted when a 2 : 1 ratio of M : L was employed. With CuI in all ratios only monomeric complexes were obtained. The synthesised complexes have been fully characterised by spectroscopic and analytical techniques and by determination of the molecular structures by single-crystal X-ray diffractometry.