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- Title
稀土金属杂环戊二烯化合物的合成及其催化活性研究.
- Authors
柳 高; 王连军; 李峥嵘; 王 岩; 陈建芳
- Abstract
A series of rare earth metallocene heterocyclic pentadienes were synthesized from Cp ✠ Li, rare earth LC13 and lithium dioxide reagent a or b in THF. Their structures and single crystals were characterized by 1H NMR, l3C NMK, FT-IR, GC-MS and X-ray single crystal diffraction, respectively. The properties and mechanism of catalytic reaction of amines or hydrazines with carhodiimides were studied in depth. The results showed that the central rare earth atom Sc of scandocene heterocyclic pentadiene is 6-coordinated, and a pentamethylcyclopentadiene anion is linked to it in the coordination mode of i)5. The Sc atom was also linked to the C in the form of covalent bond, which formed backbone of Sc heterocyclic pentadiene. In the structural unit of SC heterocyclic pentadiene, Sc atom was not in the same plane as the other four C atoms, but presented an envelope-like structure. Mono cyclopenta-diene (Cp) supported rare earth metallacyclopentadienes could catalyze the direct synthesis of guanidines from a-mines and carhodiimides, and the catalytic performance was related to the radius of rare earth ions. Under the optimum conditions, the yield of the product was up to 99%. Mono cyelopentadiene (Cp) supported rare earth metallacyclopentadienes could also catalyze the reaction of hydrazines with carhodiimides. Its catalytic mechanism was mainly related to the proton exchange between lithium ion and hydrazine. Its catalytic performance was similar, independent of rare earth ions, and different hydrazines had different products. If the substrates were I, 2-diaryl hydrazines and 1,2-dicyclohexyl carhodiimides, products were guanidine I1, and trans-azobenzene I2; If substrates were 1-methyl-1-phenylhydrazine (or 1,1-diphenylhydrazine) and I,2-dicyclohexylcarbodiimides, the products were aminoguanidine compounds I3.
- Publication
Journal of the Chinese Society of Rare Earths, 2019, Vol 37, Issue 5, p552
- ISSN
1000-4343
- Publication type
Article
- DOI
10.11785/S1000-4343.20190505