Meyer Jens, González-Gallardo Sandra, Hohnstein Silvia, Garnier Delphine, Armbruster Markus K, Fink Karin, Klopper Wim, Breher Frank
Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstrasse 15, 76131 Karlsruhe (Germany).
Chemistry. 2015 Feb 9;21(7):2905-14. doi: 10.1002/chem.201405397. Epub 2014 Dec 23.
Reactions of the tris(3,5-dimethylpyrazolyl)methanide amido complexes [M'{C(3,5-Me2 pz)3 }{N(SiMe3 )2 }] (M'=Mg (1 a), Zn (1 b), Cd (1 c); 3,5-Me2 pz=3,5-dimethylpyrazolyl) with two equivalents of the acidic Group 6 cyclopentadienyl (Cp) tricarbonyl hydrides [MCp(CO)3 H] (M=Cr (2 a), Mo (2 b)) gave different types of heterobimetallic complex. In each case, two reactions took place, namely the conversion of the tris(3,5-dimethylpyrazolyl)methanide ligand (Tpmd*) into the -methane derivative (Tpm*) and the reaction of the acidic hydride M = H bond with the M' = N(SiMe3 )2 moiety. The latter produces HN(SiMe3 )2 as a byproduct. The Group 2 representatives [Mg(Tpm*){MCp(CO)3 }2 (thf)] (3 a/b) form isocarbonyl bridges between the magnesium and chromium/molybdenum centres, whereas direct metal-metal bonds are formed in the case of the ions Zn(Tpm*){MCp(CO)3 } (4 a/b; MCp(CO)3 as the counteranion) and Cd(Tpm*){MCp(CO)3 }(thf) (5 a/b; Cd{MCp(CO)3 }3 as the counteranion). Complexes 4 a and 5 a/b are the first complexes that contain Zn - Cr, Cd - Cr, and Cd - Mo bonds (bond lengths 251.6, 269.8, and 278.9 pm, respectively). Quantum chemical calculations on 4 a/b* (and also on 5 a/b*) provide evidence for an interaction between the metal atoms.
三（3,5-二甲基吡唑基）甲烷酰胺基配合物[M'{C(3,5-Me2 pz)3 }{N(SiMe3 )2 }]（M' = Mg (1 a)，Zn (1 b)，Cd (1 c)；3,5-Me2 pz = 3,5-二甲基吡唑基）与两当量的酸性第6族环戊二烯基（Cp）三羰基氢化物[MCp(CO)3 H]（M = Cr (2 a)，Mo (2 b)）反应生成了不同类型的异双金属配合物。在每种情况下，都发生了两个反应，即三（3,5-二甲基吡唑基）甲烷配体（Tpmd*）转化为-甲烷衍生物（Tpm*）以及酸性氢化物M = H键与M' = N(SiMe3 )2 部分的反应。后者产生副产物HN(SiMe3 )2 。第2族代表物[Mg(Tpm*){MCp(CO)3 }2 (thf)]（3 a/b）在镁与铬/钼中心之间形成异羰基桥，而在离子Zn(Tpm*){MCp(CO)3 }（4 a/b；MCp(CO)3 作为抗衡阴离子）和Cd(Tpm*){MCp(CO)3 }(thf)（5 a/b；Cd{MCp(CO)3 }3 作为抗衡阴离子）的情况下形成直接的金属-金属键。配合物4 a和5 a/b是首批含有Zn - Cr、Cd - Cr和Cd - Mo键（键长分别为251.6、269.8和278.9 pm）的配合物。对4 a/b*（以及5 a/b*）的量子化学计算为金属原子之间的相互作用提供了证据。
