Franz, Alexandra, et al. Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 2020, 76(2), 267-274.
This work discussed the structural effects of deuteration on the mixed perovskite formamidinium lead tribromide (FAPbBr3). Temperature-dependent measurements showed that deuteration had a critical effect on the crystal structure, leading to a partially ordered temperature-dependent structural modification with two symmetry-independent molecular positions, as well as additional dislocations of the central atom of the molecule and molecular angular tilts.
Synthesis of (D4)-FAPbBr3
· Formamidinium acetate (16.7 g, 0.160 mol) was dissolved in 25 mL of water in a 100 mL two-neck flask. The mixture was cooled in an ice bath, and 4.5 mL of 47% aqueous hydrobromic acid (0.176 mol) in 10 mL of water was added dropwise with stirring. The resulting mixture was refluxed for approximately one hour. Water and acetic acid were then removed by rotary evaporation until a white powder formed. An additional 4.5 mL of hydrobromic acid in 10 mL of water was added, and the mixture was again evaporated to yield 19.87 g (99.35%) of formamidinium bromide as a white crystalline powder.
· In a 50 mL flask, 8 g of formamidinium bromide was dissolved in approximately 25 mL of deuterium oxide. Deuterium bromide (1-2 mL, 0.064 mol) in D2O was added, and the solution was stirred for one hour. The deuterium oxide was then removed by rotary evaporation. This process was repeated three times, yielding 7.95 g of tetradeuterated formamidinium bromide (D4).
· (D4)-FAPbBr3 powder was synthesized from stoichiometric mixtures of (D4)-FABr and PbBr2 in dimethylformamide (DMF) and homogenized overnight at room temperature, followed by evaporation of the solvent at 75 °C.
Hammond, George S., et al. Journal of the American Chemical Society, 1961, 83(11), 2554-2559.