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弯箭头在有机反应中有两种,一种是常见的??,一种是鱼钩状的??.前一种用于表示分子中或分子间一对电子的转移,后一种表示单电子转移的方向.一般教材中前一种用得多,后一种用得少,偶而在单电子转移反应中(SET),或表达一个单键的均裂时使用.而普通弯箭头则多用于表示分子极性的分化、化学键的异裂、在反应中显示亲核或亲电试剂的进攻、分子的重排、加成或消除等等. 鱼钩状箭头在表示自由基反应,例如1,3-丁二烯的1,4-加成聚合:
Bent arrows in the organic reaction in two ways, one is common ??, one is a hook-like ?? .. The former is used to represent a molecule or a pair of electron transfer between the molecules, the latter a single The general direction of the textbook is much more used, the latter is used less, occasionally in a single electron transfer reaction (SET), or to express a single bond when the split is used. Refers to the differentiation of polarities of molecules, the cleavage of chemical bonds, the attack of nucleophilic or electrophilic reagents in the reaction, the rearrangement, addition or elimination of molecules, etc. The hook-shaped arrow indicates the radical reaction such as 1 , 1,4-addition polymerization of 3-butadiene: