1: 1 and 2:1 lithium zincates with intramolecular coordination. structures of Li(thf)Zn(C₆H₄CH₂NMe₂-2)₃ and Li₂Zn(C₆H₄CH₂NMe₂-2) ₄

Homoleptic lithium zincates with intramolecular Li-N coordination, i.e., Li(thf)_nZn-(C₆H₄CH₂NMe ₂-2)₃ (n = 0 (1); n = 1 (l(thf))) and Li₂Zn(C₆H₄CH₂NMe₂-2) ₄ (2) have been prepared by reacting [Li(C₆H₄CH₂NMe₂-2)]₄ with Zn(C₆H₄CH₂NMe₂-2)₂. In the solid state l(thf) is a monomer containing a distorted tetrahedral zinc atom. The zinc is surrounded by three monoanionic C₆H₄CHe₂-2 (dmba) ligands, which all show a different bonding mode: π¹-C bonding to zinc and nitrogen coordination to lithium; π¹,μ²-C bridge bonding to zinc and lithium with Li-N coordination; and C,N-chelate bonded to zinc. One thf coordinates to lithium. In the solid state, 2 is a monomeric dilithium tetraarylzincate complex containing a tetrahedral zinc atom. The four dmba ligands are all similarly π¹,μ2-C bridgebonded to zinc and lithium, and each lithium is four-coordinate by two additional Li-N bonds. The reaction of LiCH₂SiMe₃ and Zn(C₆H₄CH₂NMe₂-2)₂ did not give a mixed zincate complex but the respective homoleptic zincate complexes instead. Both homoleptic and in situ prepared mixed zincate complexes react readily with 2-cyclohexen-l-one, but the product composition shows that the in situ prepared zincate disproportionates into the corresponding homoleptic zincates prior to reaction.