Synthesis and structure of new compounds with Zn-Ga bonds: insertion of the gallium(I) bisimidinate Ga(DDP) into Zn-X (X = CH3, Cl) and the homoleptic complex cation [Zn(GaCp*)4]2+.

Insertion reactions of the low-valent group 13 bisimidinate ligand Ga(DDP) {DDP = 2-[(2,6-diisopropylphenyl)amino]-4-[(2,6-diisopropylphenyl)imino]-2-pentene} into Zn-Me and Zn-Cl bonds are reported. The reaction of ZnMe2 with 2 equiv of Ga(DDP) yields the double-insertion product [{(DDP)GaMe}2Zn] (1), whereas the insertion of Ga(DDP) into the Zn-Cl bond of ZnCl2 in tetrahydrofuran (THF) leads to the monoinsertion product [{(DDP)GaCl}ZnCl(THF)2] (2). Treatment of 2 with Na[BArF] results in the salt [{THF.Ga(DDP)}Zn(THF)(mu-Cl)]2[BArF]2 (3), with two Cl atoms bridging the Zn centers. The structural features of the Zn-Ga-bonded compounds 1-3 were compared with related complexes and in particular with the compound [Zn(GaCp*)4][BArF]2 (4), which was synthesized by the reaction of ZnMe2, [H(OEt2)2][BArF], and GaCp* in fluorobenzene. The complex cation [Zn(GaCp*)4]2+ of 4 relates to previously reported d10 analogues [M(GaCp*)4] (M = Ni, Pd, Pt). All new compounds were fully characterized by elemental analysis, NMR spectroscopy, and single-crystal X-ray diffraction analysis.