The 1H2H, 17O1H coupling constants and the 16O/18O induced proton isotope shift in water

At very low concentration in nitromethane the coupling constants J(H,D) and J(17O,H) of the water molecule at 353 K are found to be 1.091(±0.005) and 80.6(±0.1) Hz, respectively. The high accuracy was achieved by lineshape analysis using the QUADR program for the proton resonance and temperature variation for the 17O-resonance. Measurements of the proton isotope shift due to 16O/18O substitution reveal to noticeable shift in contradiction to an early reported detection by others.