Copper Imidazolin-imine Coordination Compounds as Precursors for a Cu/Al Complex.

ABSTRACT

The reactions of [(CF3SO3Cu)2(C6H6)] with the sterically hindered imidazolin-2-imine ligands DippImTMS (1,3-Bis(2,6-diisopropylphenyl)-2-(trimethylsilylimino)imidazoline) or DippImH (1,3-bis(2,6-diisopropylphenyl) imidazolin-2-imine) lead to the formation of the linear copper(I) complexes [Cu(DippImTMS)(OTf)] (1) and [Cu(DippImH)2][OTf] (2), respectively. The triflate counteranion in 2 can be easily exchanged to the weakly coordinating [BArF] giving [Cu(DippImH)2][BArF] (3) (BArF = tetrakis[3,5-bis(trifluoromethyl)phenyl]borate). Substitution of the N-heterocyclic imine (NHI) ligand in 3 by AlCp* (Cp* = pentamethylcyclopentadienyl) gives the tetrahedral [Cu(AlCp*)4][BArF] (5). The reaction between lithiated imidazolin-2-iminate DippImLi and CuCl results in the triangular cluster [Cu3(DippIm)2Cl] (4). All products have been fully characterized by 1H- and 13C NMR, mass spectrometry, as well as SC-XRD.