Pressure effects on t H chemical shifts and rekaation rates in organic solvents containing the nitroxide radical have been observed. 'H chemical shifts with pressure and pressure-broadenings for hydrogen bonding between proton-donor molecules and the nitroxide radical have been observed. There have been several NMR studies [l-5] on dynamic and static properties of organic .nolecules in the liquid state at high pressure_ These experiments on high-pressure NMR have shown that the technique provides a useful tool for studying the behavior of solvent molecules.. We are also interested in high pressure NMR methods to investigate chemical phenomena associated with intermolecular interactions, such as hydrogen bonding and charge-transfer interactions_ We have studied pressure effects on proton chemical shifts and rehtxation times in liquids containing paramagnetic substances, and in this letter, we describe preliminary rest&s of 'H NMR chemical shifts with pressure and pressure-line-broaden&s for hydrogen-bonded protons [6] in protic solvent moIecuIes (protondonor molecules) in interaction with nitroxide radicals. Measurements were made at 60 MHz and 35ยฐC up to 10: bar, with a Hitachi cw NMR (R-24) spectrometer-CyIohe_xane was used as the internal reference since the chemical-shift difference between the internal and external cydohexane protons was independent of pressure within experimental error. Resolution of proton signals was maintained at 2 Hz at half-height_ The accuracy in the shift is f 1 Hz The line shape of t H spectra is assumed to be Iorentzian. AU T?'s were evahrated from signal widths at half-height. The high