Copper(I) tribromide dianion as a weakly-bridging, axial ligand: Synthesis of an unusual mixed-valent Cu(II)2Cu(I) trimer

A new resorcinol-substituted trimethylethylenediamine ligand and copper(II) bromide afford an unusual mixed-valent Cu(II)2Cu(I) trimer in which CuBr32- anion acts as a bridging ligand between two Cu(II) centres; the results reveal limitations to a previously reported strategy for assembly of helical coordination polymers.