THE CALCULATION OF NUCLEAR SPIN-SPIN COUPLING CONSTANTS Ⅷ. THE RELATIONSHIP BETWEEN THE COUPLING CON

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A new quantitative relationship between the coupling constants 3JH-H of substituted ethylenes and the electronegativities Ex of the substi-tuents has been proposed. It can thus be conveniently used to estimate the values of 3JH-H of substituted ethylenes, thereby identifying the type of substituents and determining the molecular configuration of disubstituted ethylenes. It is shown from the calculations of 664 3J values carried out for 414 compounds that the standard deviation between the calculated and the experimental values is 0.26 Hz.In addition, it also provides a new method for determining the electronegativities of functional groups.The electrone-gativity data of 98 substituents determined so far suffice to indicate that most of them agree fairly well with Pauling’s or revised Pauling’s electrone-gativity data of a atoms in the substituents. A new quantitative relationship between the coupling constants 3JH-H of substituted ethylenes and the electronegativities Ex of the substi-tuents has been proposed. It can thus be conveniently used to estimate the values ​​of 3JH-H of substituted ethylenes, thereby identifying the type of substituents and determining the molecular configuration of disubstituted ethylenes. It is shown from the calculations of 664 3J values ​​carried out for 414 compounds that the standard deviation between the calculated and the experimental values ​​is 0.26 Hz. addition, it also provides a new method for determining the electronegativities of functional groups. The electrone-gativity data of 98 done determined so far suffice to indicate that most of them agree fairly well with with Pauling’s or revised Pauling’s electrone-gativity data of a atoms in the substituent.
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