ISOTOPE EFFECTS ON THE C-13 CHEMICAL-SHIFT AND CARBON-PROTON COUPLING-CONSTANT IN DICHLOROMETHANE

Carbon-proton and carbon-deuteron coupling constants were measured in the isotopomers CH2Cl2, CHDCl2, and CD2Cl2. The primary and secondary isotope effects on the carbon-proton coupling are -0.60 (+/- 0.05) and -0.25 (+/- 0.01) Hz, respectively. The deuterium-induced C-13 isotope shifts proved to be almost linearly dependent on the number of deuterium atoms, although there is a small but significant non-additivity.