Synthesis and structure of alkali-metal triorganozincates

Article abstract of DOI:10.1021/om00041a030

The potassium and sodium trialkylzincates KZn(CH₂CMe₃)₃ (1), NaZn(CH₂CMe₃)₃ (2), and KZn-(CH₂SiMe₃)₃ (3) were isolated from reactions between the alkali metal and R₂Zn in benzene. The compounds all metalate benzene, and in fact KZn(CH₂SiMe₃)₂Ph (4) was isolated during the synthesis of 3. The crystal structures of 1-4 show all four complexes to consist of ZnR₃^- and K⁺ or Na⁺ ions. Potassium ions in 4 join the ZnR₃^- ions into a polymeric lattice, while 1-3 crystallize as discrete dimers. The K⁺ ions in 1 are solvated with weakly coordinated benzene, while the Na⁺ ions in 2 and the K⁺ ions in 3 have weak contacts outside the dimeric unit. Only the Na complex 2 sublimes under vacuum.