【作者】 林崇熙； 杨波； 于菲；

【Author】 Shrong-Shi Lin Bo Yang Fei Yu (College of Chemistry and Molecular Engineering,Peking University,Beijing 100871)

【机构】 北京大学化学学院；

【摘要】 <正>格氏试剂在溶液中的结构状态多年来一直存在争议,推测方法包括有凝固点下降/沸点上升数据,由低温真空干燥得到固体结晶进行X射线衍射等方法,归纳可能结构如下图所示由于格氏试剂为极活泼中间体难以提纯,文献上少有核磁共振探讨其结构的报导.更多还原

【Abstract】 The structures of Grignard reagents in solution were explored by facile ¹³C experiments.The structures studied including aliphatic and aromatic skeleton and di-Grignard molecules.The chemical shifts of the resulting carbanions moved significantly up-field and down-field for aliphatic and aromatic Grignard reagents,respectively.The structures of aromatic reagents in solution were supposed to exist as head-to-tail dimmers.Resonance phenomenon was observed for allyl Grignard reagent. The ¹³C chemical shifts of di-Grignard reagents,prepared by di-halogen molecules of at least four carbons,were noted.Electronic effects of the resulting carbanions of aromatic Grignard reagents with different substituents were observed to fit for Hammett plot and experienced equation could be induced.更多还原