Synthesis, crystal structure, Hirshfeld surface analysis, optical and antioxidant properties of the binuclear complex [C5H14N2]2Bi2Br10.4H2O

A new Bi(III) complex, [C5H14N2]2Bi2Br10.4H2O, was preparedin aqueous solutionat room temperature. This complex crystallizes in the monoclinic space group P21/n with the crystal dataa=10.368(4), b = 14.012(7), c = 11.731(9) Å, β = 99.20(4)°,V = 1682.4(17) Å3 and Z = 2.Its atomic arrangement can be described by a three-dimensional structural networkbuilt of binuclear [Bi2Br10]4−anions,uncoordinated 2-methyl piperazinium cations and water molecules. Different interactions connecting these entities are investigated by Hirshfeld surfacesanalysis. This compound,which stable up to 300 °C,absorbs at 355 nm and manifests a blue luminescence (at 442 and 480 nm) in the solid state. This compound exhibits an antioxidant activity in vitro. Four tests were donesuccessfully, 1,1-diphenyl-2-picrylhydrazyl (DPPH•), hydroxyl scavenging ability (OH•), ferric reducing power (FRP) and ferrous ion chelating (FIC) ability, using ascorbic acid as a control.