Crystal system: triclinic
| a: | 6.2455 (±0.0004) Å |
| b: | 16.8901 (±0.001) Å |
| c: | 20.1013 (±0.0011) Å |
| α: | 73.597 (±0.003)° |
| β: | 84.96 (±0.003)° |
| γ: | 88.793 (±0.003)° |
Starting materials: PbBr2(98%), 2,6-dimethylpiperazine (97%), hydrobromic acid (ACS reagent, 48%)
Product: Colorless crystals
Description: Dissolve 1.10 g (3 mmol) of PbBr2 in 4 mL of HBr under heating and stirring at 122 °C (A). Add 1 mL of HBr into a separate vial of 2,6-dimethylpiperazine (342 mg, 3 mmol). Add the protonated 2,6-dimethylpiperazine solution into A under heating for 2 min and cool to room temperature.
Method: Single-crystal X-ray diffraction
Description: Data were collected using a Bruker DUO or Molly instrument with a Mo Kα IμS microfocus source (λ = 0.71073 Å) with MX Optics at 250 K. Post-processing using APEX3 software and OLEX2 program package.
Comment: Refer to Table S4. CIF file available at DOI link.
Crystal system: triclinic
| Band gap (optical, diffuse reflectance), eV |
|---|
Starting materials: PbBr2(98%), 2,6-dimethylpiperazine (97%), hydrobromic acid (ACS reagent, 48%)
Product: Colorless crystals
Description: Dissolve 1.10 g (3 mmol) of PbBr2 in 4 mL of HBr under heating and stirring at 122 °C (A). Add 1 mL of HBr into a separate vial of 2,6-dimethylpiperazine (342 mg, 3 mmol). Add the protonated 2,6-dimethylpiperazine solution into A under heating for 2 min and cool to room temperature.
Method: Diffuse reflectance spectroscopy
Description: First, perform optical diffuse reflectance using a Shimadzu UV-3600 UV−vis−NIR spectrometer operating in the 200−1000 nm region. Convert reflectance to absorption according to the Kubelka−Munk equation to estimate the band gap.
Comment: Refer to Table 1.
Crystal system: triclinic
| Photoluminescence peak position, eV |
|---|
Starting materials: PbBr2(98%), 2,6-dimethylpiperazine (97%), hydrobromic acid (ACS reagent, 48%)
Product: Colorless crystals
Description: Dissolve 1.10 g (3 mmol) of PbBr2 in 4 mL of HBr under heating and stirring at 122 °C (A). Add 1 mL of HBr into a separate vial of 2,6-dimethylpiperazine (342 mg, 3 mmol). Add the protonated 2,6-dimethylpiperazine solution into A under heating for 2 min and cool to room temperature.
Method: Steady-state photoluminescence
Description: Excite with 330 nm photons produced from an optical parametric amplifier, which is pumped by a Ti:sapphire amplifier with 800 nm output at 2 kHz repetition rate. Time-integrated photoluminescence spectra were captured with a CCD camera; time-resolved PL spectra were captured with a streak camera.
Comment: Refer to Table 2.
Crystal system: triclinic
| Band gap (fundamental), eV |
|---|
Code: SIESTA package
Level of theory: DFT
Exchange-correlation functional: revPBE-GGA
K-point grid: Energy cutoff of 150 Ry for real-space mesh size
Level of relativity: SOC on-site approximation as proposed by Fernández-Seivane et al. (J. Phys.: Condens. Matter 2006, 18, 7999)
Basis set definition: Double-zeta polarized basis set of finite-range numerical pseudoatomic orbitals; Troullier−Martins pseudopotentials
Comment: First taken from experimental structure