MIXED AMIDE THIOLATE COMPLEXES OF ZINC WITH LOW COORDINATION-NUMBER AT THE METAL ATOM

Three different thiophenoles 2,4,6-(CF3)3C6H2SH (4), 2,4,6-(iPr)3C6H2SH (5), and 2,6-(Me3Si)2C6H3SH (6) with bulky substituents in ortho position were treated with Zn[N(SiMe3)2]2 (7) in a non-coordinating solvent like CH2Cl2 or toluene to yield mixed amide thiolate zinc complexes Zn2[N(SiMe3)2]{S[2,4,6-(CF)3C6H2]}3 (8), Zn3[N(SiMe3)2]2{S[2,4,6-(iPr)3C6H2]14 (9), and Zn2{S[2,6-(Me3Si)2C6H3]}4 (10), respectively. These compounds comprise low-coordinated zinc atoms. Initially, the reactions were performed in a 1: 1 ratio of the reactants. However, in no reaction the expected {Zn[N(SiMe3)2](SR)}x (x = 1,2,3 ... ) species were obtained but compounds which are richer in thiolate substituents (SR/NR2 > 1) even if a large excess of amide 7 was used. Distinct from these, the reaction between 7 and 2,6-iPr)2C6H3OH (14) in a 1:1 ratio afforded indeed dimer Zn2[N(SiMe3)2]2{O[2,6-(iPr)2C6H3]}2 (15). The molecular structures of 8, 9, 10, and 15 in the crystal are elucidated by X-ray structural analyses and compared with proposed structures in solution based on multinuclear NMR experiments.