Molecular reorientation and boron nuclear quadrupole interaction in crystalline ortho-carborane

摘要: Molecular reorientation in crystalline ortho‐carborane has been studied by 1H, 10B, and 11B nuclear magnetic resonance (NMR) at several frequencies, the temperature interval 155–370 K. The phase transition originally found Baughman determined our measurements to occur 274±2 o‐carborane high 1H T1 have an activation energy EA=5.8±1.3 kJ/mole. Pulse cw NMR data are consistent with a picture of which molecules undergo rapid isotropic reorientation. for low demonstrate must be anisotropic. boron lines quadrupole‐split. width shape central line functions frequency temperature. At is broad asymmetric. Evidence indicates this due mainly lifetime broadening. p...