Matrix isolation studies and DFT calculations on molecular alkali metal bromates

Abstract

DFT and MP2 calculations have been carried out on a series of molecular alkali metal bromates MBrO₃ (M = Na, K, Rb, Cs), and the results compared with matrix isolation IR studies on the vaporisation of the solid salts. For M = Na, K or Rb, no ternary molecular species were detected in the low temperature matrix, but vaporisation of solid caesium bromate at 730 K resulted in the formation of molecular CsBrO₃, which was identified as having a C_3v structure involving tridentate coordination. Additionally, the DFT and MP2 calculations provide estimates of the molecular parameters for all four MBrO₃ species, and for the related MXO₃ species CsClO₃ and CsIO₃. The proven stability of MBrO₃ molecules may have a bearing on the atmospheric chemistry of bromine oxo-species.