Electron-nuclear double-resonance study of hydrogen bonding in cadmium acetate dihydrate crystals containing Hg(I) centers

An E.S.R. and proton ENDOR study of copper-doped zinc acetate dihydrate

“…A similar conclusion has been drawn for other weakly-interacting protons involved in hydrogen-bonding [10,12]. An estimate of the orbital contribution to the isotropic coupling, made as described above, suggests that the measured value is made up of approximately equal contributions from the spin and orbital angular momenta, the estimated orbital contributions being -0.13 MHz for each of protons 3 and 3'.…”

“…We should expect the features arising from protons 1, 2 and 3 to be eliminated on deuteriation, but they are not. Similar behaviour was noted by Dalal, Hebden and McDowell in their work on cadmium acetate [10] and it was suggested that there was significant exchange of methyl protons. It seems possible therefore that the features Q in figure 6 should be assigned to the perpendicular coupling to proton 4, the magnitude being 1.72 MHz.…”