Angular dependence of deuterium spin‐lattice relaxation rates of macroscopically oriented dilauroylphosphatidylcholine in the liquid‐crystalline state

摘要: Deuterium (2H) NMR relaxation plays a major role in the study of lipid reorientational dynamics, with angular dependence rates providing novel and critical test proposed motional models. Spin‐lattice (R1Z) were measured for macroscopically oriented bilayers 1,2‐diperdeuteriolauroyl‐sn‐glycero‐3‐phosphocholine (DLPC‐d46) liquid‐crystalline (Lα) phase. The results different positions along chain (index i) dependent on angle θ between macroscopic bilayer normal static external magnetic field, allowed anisotropy R(i)1Z to be determined nine resolved quadrupolar resonances. Angular‐dependent data evaluated using simple models anisotropic rotational diffusion within an odd or even potential mean torque as framework describing (i) segmental reorientations chains, alternatively (ii) noncollective molecular motions bilayer. Moreover, (iii) quasi‐hydrodynamic fo...