Starting materials: distilled HI (aqueous 99.95%), H3PO2 (50% aqueous), SnI2 (synthesized from Sn granules, and I2 (99.8%)), CH3CH2NH3I (synthesized from CH3CH2NH2 (68.0%) and HI)
Product: pale yellow needles
Description: Two-necked flask was charged with aqueous HI (6.8 mL, 7.58 M) and aqueous H3PO2 (1.7 mL, 9.14 M). Nitrogen was passed through the liquid to degas the solution. SnI2 (372 mg, 1 mmol) was dissolved in solution, and flask was heated to boiling (~130 ºC) via an oil bath. A bright yellow solution formed under magnetic stirring. Solid CH3CH2NH3I (173 mg, 1 mmol) was added to the solution. The crystals started appearing in the solution and the solution was held at 120 °C for 2 h. Following this, the solution was cooled and the crystals were separated.
Method: UV-vis absorption (diffuse reflectance)
Description: Diffuse-reflectance measurements were performed and collected at room temperature. A Shimadzu UV-3600 PC double-beam and double monochromator spectrophotometer (operating between 200 to 2500 nm) was used.BaSO4 was used as a nonabsorbing reflectance reference. Generated reflectance v. wavelength data was used to estimate the band gap. The Kubelka-Munk equation α/S = (1-R)^{2}/(2R) was used.