Raman spectroscopic investigation of tetraethylammonium polybromides.
A large number of polyhalides, especially polyiodides, have been discovered and studied, but definitive studies on polybromides remain scarce. Br(3)(-) is the only monovalent polybromide with a known structure. Higher-order monovalent polybromide anions have been proposed but not structurally confirmed as discrete species. In this study tetraalkylammonium polybromides with molecular formulas R(4)NBr(2x+1) (R = ethyl; x = 1-4) were prepared by reacting tetraalkylammonium monobromide or tribromide salts with gas-phase bromine. Distinct and characteristic Raman spectra were obtained from the solid polybromides in the spectral range between 100 and 400 cm(-1). Experimental Raman spectra were compared to ab initio calculations to propose the structure of these polybromide anions. A general agreement between the experimental and theoretical results was observed. This study demonstrates that Raman spectroscopy is a sensitive technique for probing the structure of discrete monovalent polybromides.
Chen
Xiaoyun
X
Analytical Sciences, 1897 Building, The Dow Chemical Company, Midland, Michigan 48667, USA. xchen4@dow.com
Rickard
Mark A
MA
Hull
John W
JW
Zheng
Chao
C
Leugers
Anne
A
Simoncic
Petra
P
D001965:Bromides / Q000138:chemical synthesis / Q000737:chemistry*; D011789:Quantum Theory; D013059:Spectrum Analysis, Raman; D019789:Tetraethylammonium / Q000138:chemical synthesis / Q000737:chemistry*
D001965:Bromides; D019789:Tetraethylammonium