New SrPb3Br8 crystals: Growth, crystal structure and optical properties

(C5H6N)Pb2X5 (X = Cl, Br): Hybrid Lead Halides Based on Seven-Coordinate Pb(II)

“…Figure a and b shows that the polyhedra have slightly different shapes, with one edge of the trigonal prism in the binary halides elongated. In 1 , the seven Pb–Br bond lengths fall in the range of 2.9704(7) Å–3.2643(7) Å, in close comparison to the range of 2.9417(8) Å–3.2744(9) Å for the seven shorter bonds in PbBr 2 . In the binary bromide, two longer contacts cap the other two faces of the prism at 3.8960(6) Å.…”

“…In 1, the seven Pb−Br bond lengths fall in the range of 2.9704(7) Å− 3.2643(7) Å, in close comparison to the range of 2.9417(8) Å−3.2744(9) Å for the seven shorter bonds in PbBr 2 . 40 In the binary bromide, two longer contacts cap the other two faces of the prism at 3.8960(6) Å. In 2, the seven Pb−Cl bond lengths range from 2.8277(16) Å to 3.1285(16) Å, compared to 2.8477(44) Å to 3.0852(41) Å in PbCl 2 .…”

“…This coordination geometry is related to that in the binary lead halides, where the coordination number has been described as 7 + 2, with the seven shorter bonds forming a monocapped trigonal prism (Figure 1b). 40,44 In 1 and 2, rows of prisms share faces in the a-direction (Figure 1c), and pairs of these rows form slabs through edge-sharing (Figure 1d). Finally, the slabs share edges to form the corrugated sheets viewed end-on in Figure 2a.…”

“…This ordered structure was used without in silico relaxation so that the anionic sublattice would match the experimental one, rather than distorting due to interactions with the artificially ordered cations. For PbBr 2 , the experimental structure 40 was relaxed with van der Waals corrections (DFT−D3 with Becke−Johnson damping) 41 until the forces on the ions were less than 10 −3 eV Å −1 (relaxation without dispersion corrections resulted in a layered structure of edge-sharing, octahedrally coordinated Pb 2+ related to that of PbI 2 but with a distinct stacking order). Momentum space integration was performed on Γ-centered meshes with ∼0.3 Å −1 spacing for the self-consistent charge density (PbBr 2 : 3 × 5 × 3; PyPb 2 Br 5 : 6 × 2 × 3) and denser ∼0.1 Å −1 spacing for the DOS (PyPb 2 Br 5 : 16 × 4 × 7).…”

Nonlinear Optical Crystal Rb4Sn3Cl2Br8: Synthesis, Structure, and Characterization

“…Recently, metal halides compounds have been intensively studied for their special structural features and excellent photoelectric properties. − Typically, the fundamental building units in metal halides are [ MX k ], where M is the central metal cation and X is the halide anion with k varying from 2 to 6. − Their various connecting modes led to the pronounced structural diversity and the resulted metal halides serving as a new class of photoelectric materials widely used in photovoltaics, light emitting diodes (LEDs), nonlinear optical (NLO) materials, lasers, and photodetectors. − For example, Cs 2 HgI 2 Cl 2 , Rb 2 CdBr 2 I 2 , and K 2 SbF 2 Cl 3 can be used as infrared NLO materials, which have been considered to achieve the balance between the NLO responses and laser damage thresholds. − The organic–inorganic hybrid halides perovskites, especially CH 3 NH 3 PbI 3 , using as the light absorbing materials in solar cells, have successfully improved the power conversion efficiency to ∼22.1%. , For the remarkable optical and electric properties, it is of great interest in pursuing new metal halide compounds.…”