Stabilization and Solvent Driven Crystal-to-Crystal Transition between New Bismuth Halides

The investigations of bismuth halide chemistry in DMSO/MeOH solutions led to the discovery of a new solvent-stabilized compound with a chemical formula of Cs 3 BiBr 6 ·3DMSO. In addition, a new phase of Cs 3 BiBr 6 was generated as a result of a crystal-to-crystal transition driven by the change in the solvent composition. The solvent stabilized Cs 3 BiBr 6 ·3DMSO adopts an orthorhombic P 2 1 2 1 2 1 type crystal structure with unit cell dimension of a = 13.6160(6) Å, b = 14.4359(8) Å, and c = 14.6487(7) Å. Bulk single crystals of Cs 3 BiBr 6 ·3DMSO with average size of 4.5 × 3.5 × 3.5 mm 3 were grown by the antisolvent crystal growth method. With the change of the solvent composition from 2:1 DMSO: MeOH to 1:1 DMSO: MeOH, the single crystals of Cs 3 BiBr 6 ·3DMSO underwent a crystal-to-crystal transition yielding another structurally distinct Cs 3 BiBr 6 phase, with a tetragonal P 4 2 / m type structure and unit cell dimensions of a = 9.8394(5) Å, b = 9.8394(5) Å, and c = 8.0950(6) Å. Both compounds exhibit isolated BiBr 6 octahedral resembling the structures of the zero-dimensional (0D) perovskites.