Syntheses and crystal structures of a new family of hybrid perovskites: C₅H₁₄N₂·ABr₃·0.5H₂O (A= K, Rb, Cs)

Abstract

The syntheses and crystal structures of three hybrid perovskites, viz. poly[1-methylpiperizine-1,4-diium [tri-μ-bromido-potassium] hemihydrate], {(C5H14N2)[KBr3]·0.5H2O} n , (I), poly[1-methylpiperizine-1,4-diium [tri-μ-bromido-rubidium] hemihydrate], {(C5H14N2)[RbBr3]·0.5H2O} n , (II), and poly[1-methylpiperizine-1,4-diium [tri-μ-bromido-caesium] hemihydrate], {(C5H14N2)[CsBr3]·0.5H2O} n , (III), are described. These isostructural (space group Amm2) phases contain a three-dimensional, corner-sharing network of distorted ABr6 octahedra (A = K, Rb, Cs) with the same topology as the classical perovskite structure. The doubly protonated C5H14N2 2+ cations occupy interstices bounded by eight octahedra and the water molecules lie in square sites bounded by four octahedra. N—H...Br, N—H...(Br,Br), N—H...O and O—H...Br hydrogen bonds consolidate the structures.

Cs3Cu4In2Cl13 Nanocrystals: A Perovskite-Related Structure with Inorganic Clusters at A Sites

“…), 10 with rare examples of divalent organic cations, such as piperazine-1,4-diium (C4H12N4 2+ ) and a few others. [11][12][13][14] In our efforts to explore new metal halide materials, we have discovered a novel perovskite-related structure with a general formula Cs3Cu4In2Cl13, in the form of colloidal nanocrystals (NCs). The structure of these NCs was determined using three-dimensional electron diffraction (3D ED) on single NCs in combination with powder x-ray diffraction (XRD), as is discussed in detail below.…”

“…Perovskites (ABX 3 ) and perovskite-related compounds are some of the most chemically diverse crystal structures with many possible substitutions at A and/or B sites, as demonstrated in oxide systems. − Similarly, multinary metal halides are very versatile: many types of substitutions are known to be possible at the B sites (e.g., double and vacancy ordered perovskites) − and A sites [can be filled with both atomic (inorganic) and molecular organic cations]. − However, substitutions at the A site in multinary metal halides are mostly limited to monovalent cations (cesium, methylammonium, formamidinium, etc. ), with rare examples of divalent organic cations, such as piperazine-1,4-diium (C 4 H 12 N 4 2+ ) and a few others. − …”

Mechanisms for collective inversion-symmetry breaking in dabconium perovskite ferroelectrics

“…But the rules we develop are by no means exhaustive, since (obviously) other mechanisms can and do also drive FE order (see ref. 40 , 41 and the ODABCO[NH 4 ]Cl 3 example in ref. 1 for relevant counterexamples).…”

Ino-Chloridolithates from Ionothermal Synthesis

“…Due to the high differences in electronegativities, the high lattice energies of (pseudo)­binary salts, as well as the energetic unavailability of d -orbitals, alkali metal ions are underrepresented in coordination chemistry and are rarely known to form anionic metalates. Only a few rather counterintuitive examples were reported for the heavier elements K, Rb, and Cs: [U 2 (CN) 3 (NH 3 ) 14 ]­[KBr 6 ], (H 2 dabco )­[KCl 3 ] (dabco = 1,4-diazabicyclo[2.2.2]­octane), ( HPP )­[MBr 2 ] (HPP = piperazin-1-ium, M = Rb, Cs), and the perovskitic compounds ( Cat )­[MX 3 ] (Cat = 1-methylpiperizine-1,4-diium, 3-ammoniopyrrolidinium, dabco derivatives; M = K, Rb, Cs; X = Cl, Br, I). − The only lithium-containing compounds in this regard were obtained from molten salt syntheses in the presence of larger metal cations: M­[LiX 2 ] (M = Rb, Cs; X = F, Cl, Br), − Cs 2 [Li 2 Cl 3 ], Cs 3 [Li 2 Cl 5 ], Cs 2 [Li 3 I 5 ], Gd­[LiCl 4 ], and M­[LiF 4 ] (M = Y, Bi, Eu–Lu). − Additionally, a variety of organometallic lithate salts, such as [Li­(C­(SiMe 3 ) 3 ) 2 ] − , [Li­(N­(SiMe 3 )) 2 (SPh) 2 ] − , and [Li 2 ( diglyme )­(C 4 H 3 S) 3 ] − , are known.…”