کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1308185 | 975164 | 2010 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: ansa-Chromocenes: An alternative route to Me2Si(C5Me4)2Cr ansa-Chromocenes: An alternative route to Me2Si(C5Me4)2Cr](/preview/png/1308185.png)
The mechanism for the preparation of Me2Si(C5Me4)2Cr, 1, from CrCl2(THF)x and Me2Si(C5Me4)2Li2 was investigated and – in contrast to earlier claims – no evidence was found for the participation of an auxiliary ligand. The formation and stability of 1 is attributed to the combination of correct reaction conditions and a highly substituted ligand framework. Reactions with other ligands under identical conditions did not lead to the formation of ansa-chromocenes. Reaction with H4C2Ind2Li2 afforded the η3-Ind bridged dimer {H4C2(η5-Ind)(μ-,η3-Ind)Cr}2, 9. Complex 1 does not coordinate PPh3 or carbenes, but from reaction with two equivalents of xylyl isocyanide the CH-activated complex Me2Si(C5Me4)(η3-C5Me3(H)(CH2)Cr(CNC6MeH3)2, 7, was obtained. Complexes 7 and 9 were characterised by X-ray crystallography.
The surprising formation of ansa-chromocene in the presence of xylyl isocyanide is clarified and the participation of additional ligands in its formation could be excluded.Figure optionsDownload as PowerPoint slide
Journal: Inorganica Chimica Acta - Volume 363, Issue 8, 5 May 2010, Pages 1779–1784