Unexpected structural similarity between the chlorocopper(i) unit and the methyllithium and phenyllithium units. First complexes between (−)-sparteine and copper(i) chloride: synthesis and structural characterisation

Abstract

Two complexes containing copper(I) chloride and (−)-sparteine (spa), namely [Cu₂Cl₂spa₂] and [Cu₄Cl₄spa₂], have been synthesised from the above-mentioned constituents in the CuCl∶spa ratios 1∶1 and 2∶1, respectively. Characterisation by means of crystal-structure determination shows [Cu₂Cl₂spa₂] to be a discrete dimer and [Cu₄Cl₄spa₂] a discrete complex with an unusual Cu₄Cl₄ ladder-type core. An unexpected structural similarity between the chlorocopper(I) unit and the methyllithium and phenyllithium units, respectively, became apparent during a closer inspection of the relevant structures.