Molecular dynamics and quadrupole relaxation in solid trimethylamine- and trimethylphosphine-boron trichloride complexes

The temperature dependence of quadrupole spin-lattice relaxation time of Cl -35 nuclei has been measured in solid trimethy-lamine- and trimethylphosphi ne-boron trichloride complexes. The nature of reorientation processes occur ring in the complexes has been established and the activation parameters de termined. The obtained results indicate that in BCl3-trimethy-lamine and -t rimethylphosphine the hindered rotation of the whole complex occurs rather than uncorrelated motion of the two moieties. The motions are discussed in relation to the molecular structure of the complexes. The temperature depen dence of the Cl-35 NQR frequency of trimethylphosphine-boron trichloride is also reported. (C) 2000 Elsevier Science B.V. All rights reserved.