Organic−Inorganic Perovskites Containing Trivalent Metal Halide Layers:  The Templating Influence of the Organic Cation Layer

Abstract

Thin sheetlike crystals of the metal-deficient perovskites (H2AEQT)M2/3I4 [M = Bi or Sb; AEQT = 5,5"'-bis-(aminoethyl)-2,2':5',2'':5'',2'''-quaterthiophene] were formed from slowly cooled ethylene glycol/2-butanol solutions containing the bismuth(III) or antimony(III) iodide and AEQT.2HI salts. Each structure was refined in a monoclinic (C2/m) subcell, with the lattice parameters a = 39.712(13) A, b = 5.976(2) A, c = 6.043(2) A, beta = 92.238(5) degrees, and Z = 2 for M = Bi and a = 39.439(7) A, b = 5.952(1) A, c = 6.031(1) A, beta = 92.245(3) degrees, and Z = 2 for M = Sb. The trivalent metal cations locally adopt a distorted octahedral coordination, with M-I bond lengths ranging from 3.046(1) to 3.218(3) A (3.114 A average) for M = Bi and 3.012(1) to 3.153(2) A (3.073 A average) for M = Sb. The new organic-inorganic hybrids are the first members of a metal-deficient perovskite family consisting of (Mn+)2/nV(n-2)/nX4(2-) sheets, where V represents a vacancy (generally left out of the formula) and the metal cation valence, n, is greater than 2. The organic layers in the AEQT-based organic-inorganic hybrids feature edge-to-face aromatic interactions among the rigid, rodlike quaterthiophene moieties, which may help to stabilize the unusual metal-deficient layered structures.

Robust motifs in 2-phenylethylammonium and related tetrahalometallates

“…In the structures 2phenZnBr, 2, 2phenZnI, 3, 2phenCdI, 6, 2phenHgI, 9, and 2phenZnCl 2 BrI, 10, cations containing atom N2 adopt similar geometries, with q values ranging from 75 (1) to 89 (2) . Structures 2phenCdBr, 5, 2phenHgBr, 8, and 2phenCd/HgBr, 11 (all bromo-ligand containing), exhibit q angles in the range 64.7 (8) to 67 (1) .…”

Naturally Self-Assembled Nanosystems and Their Templated Structures for Photonic Applications

“…These self-assembling inorganic-organic perovskites adopt an alternating framework of semiconducting inorganic sheets and organic layers. The increasing interest is because of the ability to derive low-dimensional crystals, which show unique crystal structure and physical and optical properties, from parent 3D networks of AMX 3 from simple and effective natural self-assembly [32][33][34][35][36][37][38][39][40][41][42][43]. These materials involve different types of interactions allowing the assembly of complex and highly-ordered structures with various bonding schemes.…”

“…Recent efforts in the crystal engineering resulted into the reduction of structures into 0, 1, 2, or 3-low-dimensional hybrid networks [32,33,77,[83][84][85][86][87]. The dimensionality of these IO-hybrids, based on the bridging of organic moiety between the MX one-dimensional planes, is critically dependent on (1) the choice of hydrogen bonding scheme between protonated amine terminal group(s) of organic moiety and the MX network and (2) the driving force, size, and shape of the organic molecule [80].…”

“…The dimensionality of these IO-hybrids, based on the bridging of organic moiety between the MX one-dimensional planes, is critically dependent on (1) the choice of hydrogen bonding scheme between protonated amine terminal group(s) of organic moiety and the MX network and (2) the driving force, size, and shape of the organic molecule [80]. The simplest MX 4 2− network consists of corner-sharing metal halide octahedra oriented along ⟨100⟩ plane and, based on how the organic is intercalated into the parental network, intercalated structures of 0D, 1D, 2D, and 3D can be expected [32,33,48,86,88,89]. In the two-dimensional R-MX 4 type hybrids, (MX 4 )…”

Metal Halide Perovskite Single Crystals: From Growth Process to Application

“…In a typical perovskite crystal structure, the A, B, and X ionic radii, e.g., R A , R B , and R X , should correspond to a specific geometric relationship, known as the Tolerance factor [28][29][30]: t = (R A + R X )/ √ 2(R B + R X ). The ideal value of t should be 1 for cubic structures; otherwise, the structure tends to be distorted, or even destroyed [28,30,31]. For lead hybrid perovskite, the large organic cation at the A position, e.g., methylammonium (MA + ) or formamidinium (FA + ), is able to match the large radius of the Pb 2+ ion at the B position and meet the tolerance factor t, while the halogen anions or their mixtures occupy the C positions, resulting in the formation of a 3D perovskite structure [32].…”