1. Crystal structure, optical properties, and theory study of a 1-D bromoplumbate stabilized by in situ generated N -alkylated DABCO cation.
- Author
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Tong, Hua-Nan, Lin, Jian-Di, Rong, Cheng, Li, Jing-Min, Wang, Yu-Lin, Guo, Guo-Cong, and Lv, Ri-Xin
- Subjects
CATIONS ,BAND gaps ,SEMICONDUCTORS ,PHOTOLUMINESCENCE ,PHOTOEXCITATION - Abstract
We report the exploration of the stabilization effect of the in situ generated N-alkylated DABCO (DABCO = 1,4-diazabicyclo[2.2.2]octane) cation in the family of bromoplumbates and a 1-D bromoplumbate, (Et
2 DABCO)2n (Pb3 Br10 )n (1), has been prepared by solvothermal conditions. Optical diffuse reflectance determination shows the band gap of 1 is 3.69 eV, which manifests that 1 is a wide band gap semiconductor. Compared with the band gap of bulk PbBr2 (3.84 eV), 1 exhibits 0.15 eV red shift of absorption edge. While for the reported iodo analogs of this compound, (MPDA)2n (Pb3 I10 )n and (Et2 DABCO)2n (Pb3 I10 )n , they exhibit 0.53 and 0.47 eV blue shift of the energy gaps compared with the measured value of 2.30 eV for bulk PbI2 , respectively. The photoluminescent study of 1 shows that it exhibits a broad emission band centered at 697 nm upon photoexcitation by 345 nm (amount to 3.59 eV). The calculated density of states manifests the theoretical value of the band gap of 1 is 3.422 eV and the origination of photoluminescence can be ascribed to the transition of bonding electrons of Brโ anion to the empty orbits of Pb(II) ion. [ABSTRACT FROM AUTHOR]- Published
- 2017
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