ChemInform Abstract: Preparation of the Binary Technetium Bromides: TcBr3and TcBr4

TcBr3 (1) and TcBr4 (2) were synthesized by reaction of Tc metal with elemental bromine at 400 °C. Single crystal XRD measurements indicate that TcBr3 crystallizes in the orthorhombic space group Pmmn (a = 11.0656(2) A, b = 5.9717(1) A, c = 6.3870(1) A). The structure consists of infinite chains of face-sharing TcBr6 octahedra with a regular alternation of short and long Tc−Tc distances (2.8283(4) A, 3.1434(4) A). TcBr4 crystallizes in the orthorhombic space group Pbca (a = 6.3237(5) A, b = 12.1777(9) A, c = 14.7397(11) A). TcBr4 contains infinite chains of edge-sharing TcBr6 octahedra with no apparent metal−metal bond (Tc−Tc = 3.7914(4) A). Technetium tribromide is isomorphous with RuBr3 and MoBr3, while TcBr4 is isomorphous with PtBr4 and OsBr4.