NUCLEAR SPIN-SPIN COUPLING CONSTANT AND MOLECULAR STRUCTURE——Ⅰ. The Relationship between Coupling Constants and Bond Lengths (Internuclear Distances)

作     者：Yang Wen-Huo Lu Ge -TanFujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou,350002 

出 版 物：《Chinese Journal of Structural Chemistry》 (结构化学(英文版))

年 卷 期：1993年第2期

页      面：146-154页

核心收录：

主　　题：NUCLEAR SPIN-SPIN COUPLING CONSTANT AND MOLECULAR STRUCTURE The Relationship between Coupling Constants and Bond Lengths 

摘      要：A discussion on the relationship between nuclear spin-spin coupling constants and bond lengths (internuclear distances) will be presented in this paper. The discussion will be focussed on the R-3 rule, the limit of its application and its influencing factors. Specifically, the causes for two long-existing puzzles in NMR coupling constants will be discussed: (a) the abnormal values of the coupling constants in ethylene and acetylene and (b) the methyl-substitution rule. It will be pointed out that in solution the coupling of intramolecular nuclear spins is affected by many factors and thus will not strictly obey the R-3rule in general. However, in practice, the R-3 rule will still be valid when various influencing factors are carefully taken into consideration.