Zincation of primary amines: Synthesis and structures of dimeric alkylzinc amides

The zincation of triisopropylsilylamine with dimethyl- and diethylzinc yields dimeric methylzinc (1) and ethylzinc triisopropylsilylamide (2). Complex 1 crystallizes in the monoclinic space group P2₁/n, 2 in P2₁/c. The reaction of dimethylzinc with adamantylamine gives [(THF)ZnMe][(AdNH₂)ZnMe][μ-N(H)Ad]₂ (3) which crystallizes in the monoclinic space group P2₁/n. All these compounds have central Zn₂N₂ cycles. Contrary to 1 and 2 with triply coordinated metal centers, the zinc atoms in 3 show a distorted tetrahedral coordination sphere due to the contact to the neutral coligands THF and adamantylamine.