| 释义 |
nucleophilic, a. Chem.|njuːklɪəˈfɪlɪk|
[f. nucleo- + -philic.]
a. Having an affinity for atomic nuclei, and so reacting at an electron-deficient bond or atom in a substrate; anionoid.
1933C. K. Ingold in Jrnl. Chem. Soc. 1121 The terms electrophilic (electron-seeking) and nucleophilic (nucleus-seeking) are suggested in place of the adjectives anionoid and cationoid introduced by Lapworth. 1946Nature 20 July 94/1 Those bimolecular and unimolecular substitutions in which a nucleophilic reagent displaces halogen as halide ion from an alkyl halide. 1968R. O. C. Norman Princ. Org. Synthesis iv. 127 A thiol anion, RS-, although less basic than its oxygen analogue, RO-, is more strongly nucleophilic.
b. Of a reaction: brought about by a nucleophilic reagent.
1935Hughes & Ingold in Jrnl. Chem. Soc. 245 According as this [sc. the substituting agent] is nucleophilic..or electrophilic.., the reaction may be termed a ‘nucleophilic’ or ‘electrophilic’ substitution. 1946Nature 20 July 94/1 That the polar effect is not absent in general from bimolecular nucleophilic substitutions is consistent with the result of exchanging the electron-releasing methyl substituents for electron-attracting groups. 1969T. C. Thorstensen Pract. Leather Technol. vi. 91 Windus and Showell have reported the explanation of mechanism of unhairing as a nucleophilic displacement.
Hence nucleoˈphilically adv., after the manner of a nucleophile; ˌnucleophiˈlicity, nucleophilic character.
1953C. K. Ingold Struct. & Mech. Org. Chem. v. 201 Basicity..is a special manifestation of nucleophilic character, or nucleophilicity, that is, affinity for atomic nuclei in general. 1970J. E. Gearin in A. Burger Medicinal Chem. (ed. 3) II. xlvii. 1302/2 This group must be capable of attacking nucleophilically the carbon atom of the ester group of acetylcholine. 1971C. J. Gray Enzyme-catalysed Reactions i. 21 The nucleophilicity of the small fluoride ion is higher in non-hydroxyl solvents where the solvation is less effective. |