NbBr4

Niobium bromide, NbBr4, is a chemical compound of niobium and bromine. It exists as a dark brown crystalline solid. NbBr4 is a relatively stable compound under ambient conditions, though it is sensitive to moisture and air. When exposed to water, it undergoes hydrolysis, producing niobium oxybromides and hydrobromic acid. The compound is typically synthesized through the direct reaction of niobium metal with bromine vapor at elevated temperatures, often in a sealed vessel. The crystalline structure of NbBr4 is characterized by polymeric chains of niobium atoms bridged by bromine atoms. Each niobium atom is octahedrally coordinated by six bromine atoms, with some bridging and some terminal bromine atoms. The compound is an electrical insulator. NbBr4 has found limited applications, primarily in research settings, due to its reactivity and the availability of alternative niobium compounds. Its properties make it a subject of interest in the study of niobium halide chemistry and materials science.