The Effect of Substituents on the Phenyl Portion of the Imido Ligand on the Structure and Properties of Molybdenum(VI) Imido Complexes
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- 作者：Martin Minelli ; My Le Hoang ; Michael Kraus ; Gena Kucera ; Jennifer Loertscher ; Mark Reynolds ; Nathan Timm ; Michael Y. Chiang ; and Douglas Powell
- 刊名：Inorganic Chemistry
- 出版年：2002
- 出版时间：November 18, 2002
- 年：2002
- 卷：41
- 期：23
- 页码：5954 - 5960
- 全文大小：159K
- 年卷期：v.41,no.23(November 18, 2002)
- ISSN：1520-510X
文摘
Anilines with alkyl substituents on the phenyl ring (ArNH2 = 2,4,6-trimethylaniline; 2,3-, 2,4-, 2,6-, and3,4-dimethylaniline; and 2,6-diisopropylaniline) react with MoO(X)2(dtc)2 (X = Cl or Br; dtc = diethyldithiocarbamate)in methanol in the presence of 2 equiv of triethylamine to form ionic imido complexes of the type [MoNAr(dtc)3]2[Mo6O19] or MoNAr(dtc)3]4[Mo8O26]. The same reaction in THF with butyllithium as base yields imido complexes ofthe type MoNAr(X)2(dtc)2. The structures of three ionic, five chloro, and two bromo complexes have been determinedby X-ray crystallography. In all complexes, the molybenum center is a distorted pentagonal bipyramid. While thestructures are similar, the angles of the imido linkages differ. The effect of the substituents on the phenyl ring ofthe imido ligand on the 95Mo NMR chemical shifts was determined. The Mo nucleus becomes more deshieldedwith the substituents in the following order: 3,4-Me2 < 2,3-Me2 < 2,4-Me2 < 2,6-Me2 < 2,4,6-Me3 < 2,6 isopropyl.Complexes with more deshielded 95Mo centers tend to have angles of the imido linkage that are closer to 180
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