35Cl/37Cl one-bond isotope effects on 13C chemical shifts in a series of para-substituted chlorobenzenes

✍ Scribed by Martha S. Morales-Ríos; Cirilo García-Martínez; Pedro Joseph-Nathan; L. Gerardo Zepeda

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 229 KB
• Volume: 33
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1260330212

✦ Synopsis

Abstract

One‐bond isotope shifts of ^35^Cl/^37^Cl natural abundance chlorine isotopomers were measured in the 75.4 MHz ^13^C NMR spectra of a series of para‐substituted chlorobenzenes. The high‐field isotope shift effect ^1^Δ^13^C(^37^Cl) was established from the relationship between the chlorine isotopomeric ratio and the carbon peak intensities. It was found that the ^1^Δ^13^C(^37^Cl) values are in the range of −4.0 to −5.2 ppb. The isotope shifts tend to decrease as the electron‐attracting character of the substituent increases, providing a linear correlation between the isotope shift and the chemical shift of the chlorine‐bearing carbon.