Analytical Sciences, 1897 Building, The Dow Chemical Company, Midland, Michigan 48667, USA.
Inorg Chem. 2010 Oct 4;49(19):8684-9. doi: 10.1021/ic100869r.
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.
大量的多卤化物,特别是多碘化物,已经被发现和研究,但对多溴化物的明确研究仍然很少。Br(3)(-) 是唯一具有已知结构的单价多溴化物。更高价的单价多溴化物阴离子已被提出,但尚未作为离散物种得到结构确证。在这项研究中,通过将四烷基溴化铵单溴化物或三溴化物盐与气相溴反应,制备了分子式为 R(4)NBr(2x+1)(R = 乙基;x = 1-4)的四烷基溴化铵多溴化物。从固态多溴化物在 100 到 400 cm(-1) 的光谱范围内获得了独特且特征的拉曼光谱。将实验拉曼光谱与从头算计算进行了比较,以提出这些多溴化物阴离子的结构。实验结果与理论结果之间存在普遍的一致性。这项研究表明,拉曼光谱是探测离散单价多溴化物结构的敏感技术。