Synthesis, Characterization, and Thermal Rearrangement of Zirconium Tetraazadienyl and Pentaazadienyl Complexes

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• 作者：Thorsten Gehrmann ; Julio Lloret Fillol ; Hubert Wadepohl ; Lutz H. Gade
• 刊名：Organometallics
• 出版年：2012
• 出版时间：June 25, 2012
• 年：2012
• 卷：31
• 期：12
• 页码：4504-4515
• 全文大小：640K
• 年卷期：v.31,no.12(June 25, 2012)
• ISSN：1520-6041

文摘

Reaction of the zirconium dichloro complex [Zr(N₂^TBSN_py)Cl₂] (1) with 1 molar equiv of ArNHLi (Ar = Mes, DIPP) yielded the zirconium imido complexes [Zr(N₂^TBSN_py)(鈺怤^DIPP)(py)] (2; N₂^TBSN_py = [(2-C₅H₄N)C(CH₃){CH₂NSi(CH₃)₂tBu}₂]^{2鈥?/sup>, DIPP = 2,6-diisopropylphenyl) and [Zr(N₂TBSN_py)(鈺怤Mes)(py)] (3; Mes = mesityl). The imido complexes are converted to the tetraazadienido complexes [Zr(N₂TBSN_py)(NDIPPN₂NPh)] (4) and Zr(N₂TBSN_py)(NMesN₂NPh)] (5) by addition of phenyl azide, whereas the reaction of 2 or 3 with mesityl azide gave the alternative product 7, in which the azide is coupled with the CH activated ancillary tripod ligand. Reaction of 1 molar equiv of trimethylsilyl azide or 1-adamantyl azide with the previously reported hydrazinediido complex [Zr(N₂TBSN_py)(鈺怤NPh₂)(py)] (9) at ambient temperature resulted in the formation of the five-membered zirconaacacycles [Zr(N₂TBSN_py)(NTMSN₃NPh₂)] (10) and [Zr(N₂TBSN_py)(NAdN₃NPh₂)] (11). Complex 11 was thermally converted into the diazenido complex 12 via loss of 1 molar equiv of molecular N₂. The direct formation of the analogous side-on-bonded diazenido analogue 13 was observed upon reaction of 9 with 1 equiv of mesityl azide at ambient temperature. On the basis of 15N labeling and DFT modeling (DFT(B3PW91/6-31 g(d))) a mechanism for the reaction pathway leading to 12 and 13 is proposed.}