Crystal system: monoclinic
| Band gap (optical, diffuse reflectance), eV |
|---|
Starting materials: Lead(II) oxide (PbO, <10 μm, ReagentPlus®, ≥99.9% trace metals basis ), HI (57 wt. % in H2O), methylamine hydrochloride (≥98%), pentylamine 99%, H3PO2 (50 wt. % in H2O)
Product: red plate-like crystals
Description: PbO powder (2232 mg, 10 mmol) was dissolved in 57% w/w aqueous HI solution (16 mL) in a 50 mL glass flask by heating to boiling under stirring. A bright yellow solution resulted. Solid methylamine hydrochloride (338 mg, 5 mmol, DRY) was added to the hot yellow solution, and a black powder precipitated. This dissolved under stirring and resulted in a bright yellow solution. 911 μL (6.9 mmol) of pentylamine in 50% aqueous H3PO2 (2 mL) was slowly added. The solution was slowly cooled to room temperature. After two hours, crystals were completely formed.
Method: UV-vis absorption (diffused reflectance)
Description: Optical diffuse-reflectance measurements were conducted at room temperature. A Shimadzu UV-2600 PC double-beam, double-monochromator spectrophotometer was operating from 200 to 2500 nm. BaS4 was used as a non-absorbing reflectance reference. Reflectance v. wavelength data was collected and used to estimate the band gap by converting reflectance to absorbance via the Kubelka-Munk equation: α/S = (1-R)^{2}/2R. Band gap energy was calculated based on the absorption edge and exciton peak of the optical absorption spectra.
Crystal system: monoclinic
| Band gap (optical, diffuse reflectance), eV |
|---|
Starting materials: Lead(II) oxide (PbO, <10 μm, ReagentPlus®, ≥99.9% trace metals basis ), HI (57 wt. % in H2O), methylamine hydrochloride (≥98%), pentylamine 99%, H3PO2 (50 wt. % in H2O)
Product: red plate-like crystals
Description: PbO powder (2232 mg, 10 mmol) was dissolved in 57% w/w aqueous HI solution (16 mL) in a 50 mL glass flask by heating to boiling under stirring. A bright yellow solution resulted. Solid methylamine hydrochloride (338 mg, 5 mmol, DRY) was added to the hot yellow solution, and a black powder precipitated. This dissolved under stirring and resulted in a bright yellow solution. 911 μL (6.9 mmol) of pentylamine in 50% aqueous H3PO2 (2 mL) was slowly added. The solution was slowly cooled to room temperature. After two hours, crystals were completely formed.
Method: UV-vis absorption (diffused reflectance)
Description: Optical diffuse-reflectance measurements were conducted at room temperature. A Shimadzu UV-2600 PC double-beam, double-monochromator spectrophotometer was operating from 200 to 2500 nm. BaS4 was used as a non-absorbing reflectance reference. Reflectance v. wavelength data was collected and used to estimate the band gap by converting reflectance to absorbance via the Kubelka-Munk equation: α/S = (1-R)^{2}/2R. Band gap energy was calculated based on the absorption edge and exciton peak of the optical absorption spectra.