Multi‐frequency, variable‐temperature and high‐pressure study of carbon‐13 spin—lattice relaxation in tetraoctyltin

Abstract

AbstractCarbon‐13 NMR spin–lattice relaxation times, T1, and nuclear Overhauser effect data were obtained for neat tetra‐n‐octyltin at 22.5 and 100.6 MHz over a wide temperature range. T1 values were also measured at 25.16 MHz at pressures up to 211 MPa. The ambient‐pressure data were fitted to the ‘model‐free’ two‐correlation time spectral density with a temperature‐dependent order parameter, S2. The pressure data were interpreted by assuming that internal motions of the octyl chain are independent of pressure while the overall (tumbling) motion and S2 are pressure dependent. The values of the motional parameters for tetra‐n‐octyltin lie in the ranges expected for compounds containing long n‐alkyl chains. The results show that this approach is applicable to complex liquids such as synthetic lubricants of the polydecene type.