Terminal Titanium-Ligand Multiple Bonds. Cleavages of C=O and C=S Double Bonds with Ti Imido Complexes

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• 作者：Shih-Hsien Hsu ; Jr-Chiuan Chang ; Chun-Liang Lai ; Ching-Han Hu ; Hon Man Lee ; Gene-Hsiang Lee ; Shie-Ming Peng ; and Jui-Hsien Huang
• 刊名：Inorganic Chemistry
• 出版年：2004
• 出版时间：October 18, 2004
• 年：2004
• 卷：43
• 期：21
• 页码：6786 - 6792
• 全文大小：174K
• 年卷期：v.43,no.21(October 18, 2004)
• ISSN：1520-510X

文摘

Treatment of ^t-BuN=TiCl₂Py₃ with 2 equiv lithium ketiminate compound, Li[OCMeCHCMeN(Ar)] (where Ar =2,6-diisopropylphenyl), in toluene at room temperature gave ^t-BuN=Ti[OCMeCHCMeN(Ar)]₂ (1) in high yield.The reaction of 1 with phenyl isocyanate at room-temperature resulted in imido ligand exchange producingPhN=Ti[OCMeCHCMeN(Ar)]₂ (2). Compound 1 decomposed at 90 C to form a terminal titanium oxo compoundO=Ti[OCMeCHCMeN(Ar)]₂ (3) and ^t-BuNHCMeCHCMeNAr (4). Also, the compound 3 could be obtained by reacting1 with CO₂ under mild condition. Similarly, while 1 reacts with an excess of carbon disulfide, a novel terminaltitanium sulfido compound S=Ti[OCMeCHCMeN(Ar)]₂ (5) was formed via a C=S bond breaking reaction. A noveltitanium isocyanate compound Ti[OCMeCHCMeN(Ar)]₂(NCO)(OEt) (6) was formed on heating 1 with 1 equiv ofurethane, H₂NCOOEt. Compounds 1-6 have been characterized by ¹H and ¹³C NMR spectroscopies. The molecularstructures of 1, 3, 5, and 6 were determined by single-crystal X-ray diffraction. A theoretical calculation predictedthat the cleavage of the C-S double bonds for carbon disulfide with the Ti=N bond of compound 1 was estimatedat ca. 21.8 kcal·mol^-1 exothermic.