An investigation of H-1 and C-13 longitudinal relaxation and relaxation inthe rotating frame in solid poly(N-vinylcarbazole)

H-1 and C-13 longitudinal relaxation times (T-1) and relaxation times in th e rotating frame (T-1p) have been measured for poly(N-vinylcarbazole) in th e solid state in air and nitrogen atmospheres in an attempt to elucidate mo lecular motions. In air, the T-1 relaxation of both H-1 and C-13 was domina ted by interaction with absorbed paramagnetic oxygen. In nitrogen, the 13C Ti relaxation times were long (> 300s) and were averaged by C-13-C-13 spin diffusion. The C-13 T-1p relaxation times showed an exponential dependence on the strength of the rotating C-13 magnetic field and were thus controlle d by spin-spin processes rather than spin-lattice processes. (C) 2001 Socie ty of Chemical Industry.