翻訳と辞書 |
Carbenium ion : ウィキペディア英語版 | Carbenium ion
A carbenium ion is a positive ion with the structure RR'R''C+, that is, a chemical species with one trivalent carbon that bears a +1 electric charge. In older literature the name carbonium ion was used for this class, but now it refers exclusively to another family of carbocations, the carbonium ions, where the charged carbon is pentavalent.〔IUPAC Gold Book (''carbonium ion'' )〕 The current definitions were proposed by the chemist George Andrew Olah in 1972,〔''Stable carbocations. CXVIII. General concept and structure of carbocations based on differentiation of trivalent (classical) carbenium ions from three-center bound penta- of tetracoordinated (nonclassical) carbonium ions. Role of carbocations in electrophilic reactions'' George Andrew Olah; J. Am. Chem. Soc.; 1972; 94(3); 808-820.〕 and are now widely accepted. Carbenium ions are generally highly reactive due to having an incomplete octet of electrons; however, certain carbenium ions, such as the tropylium ion, are relatively stable due to the positive charge being delocalised between the carbon atoms. ==Nomenclature ==
Carbenium ions are classified as primary, secondary, or tertiary depending on whether the number of carbon atoms bonded to the ionized carbon is 1, 2, or 3. (Ions with zero carbons attached to the ionized carbon, such as methenium, , are usually included in the primary class).
抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Carbenium ion」の詳細全文を読む
スポンサード リンク
翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|