出典:Wiktionary
From the resonance structure between the covalent form (-yl, where the carbanion exists as a methylidenyl group) and the ionic form (-ide, as in methanide).
出典:Wikipedia
出典:『Wikipedia』 (2011/05/12 03:28 UTC 版)
An ylide or ylid (pronounced /ˈɪlɪd/ or /ˈɪlaɪd/) is a neutral dipolar molecule containing a formally negatively charged atom (usually a carbanion) directly attached to a hetero atom with a formal positive charge (usually nitrogen, phosphorus or sulfur), and in which both atoms have full octets of electrons. Ylides are thus 1,2-dipolar compounds. They appear in organic chemistry as reagents or reactive intermediates.