Synthesis, Characterization, and Reactivity of Multinuclear Zinc(II) Alkyl Derivatives of Linked Phenoxides

Alkyl zinc derivatives of tris(3,5-dialkyl-2-hydroxyphenyl)methanes (alkyl = tert-butyl 1a, methyl 1b, tert-pentyl 1c) have been prepared by reaction with dimethyl or diethylzinc, and characterized. Whereas dimethylzinc with 1a or diethylzinc with 1b give S6 symmetric, hexanuclear aggregates with the general formula 12(ZnR)6 (R = Me 2a, Et 2b), when 1a reacts with diethylzinc, solvent dependent reactions take place. If dichloromethane is used for the reaction solvent, a dimeric, C2 symmetric, tetranuclear product with the formula 1a2Zn2(ZnEt)2 (3) is isolated while in diethyl ether, a C2 symmetric, pentanuclear aggregate 1a2Zn(ZnEt)4 (4) forms, and in tetrahydrofuran a C3 symmetric trinuclear compound 1a[ZnEt(THF)]3 (5a) is produced. Each example is represented by a single-crystal X-ray structure determination. Preliminary studies regarding their activity toward the copolymerization of cyclohexene oxide and carbon dioxide are also reported.