Molecular motions and phase transitions in solid bis-n-propylammonium pentabromoantimonate.

ABSTRACT

The proton nuclear magnetic resonance (NMR) second moment and spin-lattice relaxation time for polycrystalline bis-n-propylammonium pentabromoantimonate (nPBA) have been measured from 70 to 290 K. The results are interpreted in terms of the CH3 and NH3 group reorientations for which the activation parameters have been determined. A structural phase transition evidenced at about 220 K is found in the polycrystalline sample of nPBA.