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

ABSTRACT

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 Cs3BiBr6·3DMSO. In addition, a new phase of Cs3BiBr6 was generated as a result of a crystal-to-crystal transition driven by the change in the solvent composition. The solvent stabilized Cs3BiBr6·3DMSO adopts an orthorhombic P212121 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 Cs3BiBr6·3DMSO with average size of 4.5 × 3.5 × 3.5 mm3 were grown by the antisolvent crystal growth method. With the change of the solvent composition from 21 DMSO MeOH to 11 DMSO MeOH, the single crystals of Cs3BiBr6·3DMSO underwent a crystal-to-crystal transition yielding another structurally distinct Cs3BiBr6 phase, with a tetragonal P42/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 BiBr6 octahedral resembling the structures of the zero-dimensional (0D) perovskites.