NMR Relaxation Times in Solid White Phosphorus: Diffusion and Rotation

Nuclear magnetic resonance relaxation times have been measured for solid white phosphorus by spin-echo techniques. The diffusion coefficient calculated from T2 in the α phase can be represented as D=D0exp(−ΔH/RT),where D0=0.077±0.014 cm2/sec, and ΔH=12.1±0.1 kcal/mole. The correlation time for rotation calculated from T1 in the β phase can be represented by tc=t0exp(ΔH/RT),where t0=6.04×10—14 sec, and ΔH=4.02±0.02 kcal/mole. The distance between phosphorus atoms in the P4 molecule is found to be 2.24±0.03 Å from the value of T1 at the T1 minimum in the β phase.