Synthesis of Trinuclear, Dinuclear and Mononuclear Carbamato‐Zinc Complexes from Tetranuclear Precursors: A Top‐Down Synthetic Approach to New Carbamates

In this work we report on the synthesis of new mono‐, bi‐ and trinuclear carbamato‐Zn complexes by reaction of the tetranuclear precursor [ZnEt(O2CNR2)]4 (R = iPr and iBu) with the nitrogen bases pyridine, N,N,N′,N′‐tetramethylguanidine (tmg) and bis(N,N,N′,N′‐tetramethylguanidino)naphthalene (btmgn). The only reaction product obtained with pyridine is the dinuclear complex [(py)ZnEt(O2CNR2)]2. In the case of reaction of [ZnEt(O2CNR2)]4 with tmg, the dinuclear species [(tmg)ZnEt(O2CNR2)]2 (for molar ratios of 1:4) and the mononuclear bis‐carbamato complex [(tmg)2Zn(O2CNR2)2] (for molar ratios of 1:8) were obtained. Finally, the mono‐ and trinuclear carbamates [(btmgn)ZnEt(O2CNR2)] and [(btmgn)Zn3Et3(O2CNR2)3] were formed in the reaction between [ZnEt(O2CNR2)]4 and btmgn (molar ratios 1:4 and 1:2, respectively). All products were structurally characterized by X‐ray diffraction. Using this top‐down approach the synthesis of a variety of oligonuclear carbamato‐Zn complexes becomes possible. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)