Proton magnetic resonance in methyl alcohol and methyl mercaptan

Measurements are reported of the nuclear magnetic resonance parameters of methyl alcohol and methyl mercaptan (CH3SH). The spin-lattice relaxation time T1 and the chemical shift δ have been measured for both liquids, and for both types of proton for T1 from the supercooled liquid up to the critical temperature. The variations of both T1 and δ reflect the considerable difference in the importance of hydrogen bonding in the two liquids. At low temperatures the T1 values are controlled by direct dipolar interaction. At higher temperatures the T1 values depend on the spin-rotation interaction and approximate values of the operative spin-rotation interaction constants are deduced and shown to be reasonable in magnitude. Some preliminary measurements in the dense mercaptan gas near the critical temperature are also reported.