The motley family of polar compounds (MV)[M(X5−xX′x)] based on anionic chains of trans-connected M(III)(X,X′)6 octahedra (M=Bi, Sb; X, X′=Cl, Br, I) and methylviologen (MV) dications

Optical Properties of Hybrid Organic‐Inorganic Materials and their Applications

“…This effect is used in hybrids including viologens (1,1 -disubstituted-4,4 -bipyridinium, V 2+ cations) to afford stable separated charge state systems that find applications in electrochromic displays, [182] One pioneer result was found in (MV)[MX 5-x X x ] ((M = Bi III , Sb III ; X = Cl, Br, I; x = 0-5) compounds that exhibited ferroelectric properties thanks to the electron-donor interaction of a methylviologen dication with polar MX 5 chains of transconnected octahedra (Figure 15). [183] Asymmetric viologen ligands can be also coordinated to Zn(II) centers through a template effect, leading to the first example of bulk electron-transfer photochromic compound with intrinsic second-order nonlinear optical (NLO) photoswitching properties. [184] The electron transfer is possible thanks to the synergetic interaction between the ligand and a metal center with acentric coordination geometry (Figure 16).…”

Ferroelectricity in bis(ethylammonium) pentachlorobismuthate(iii): synthesis, structure, polar and spectroscopic properties

“…[1][2][3][4] Haloantimonates(III) and halobismuthates(III) of the general formula R a M b X 3b+a (where R is organic cations M = Sb, Bi and X = Cl, Br, I) constitute an important class of functional materials characterized by a number of interesting electrical/ ferroelectric, elastic/ferroelastic and nonlinear optical (NLO) properties and act as potential lead-free absorber materials for solar cells. [5][6][7][8][9][10][11][12] Numerous structural studies have shown that Sb III /Bi III halide derivatives based on different organic amines exhibit a rich diversity of the anionic structures. 13,14 These systems usually consist of zero-(0D), one-(1D), two-(2D) and rarely three-dimensional (3D) inorganic networks.…”

“…14 In recent years, the research on nonlinear organicinorganic hybrids gained new impetus with the discovery of ferroelectricity within haloantimonates(III) and halobismuthates(III) crystallizing with the chemical stoichiometry: R 2 MX 5 . [5][6][7][8][9][10] It should be stressed that for this composition only three ferroelectrics have been reported so far, (MV)BiBr 5 (where MV 2+ is methylviologen dication) with the trans configuration of the [MX 5 ] 2− ∞ chains, (H 2 dmdap)SbCl 5 (dmdap = N,N-dimethyl-1,3-diaminopropane) and (C 3 N 2 H 5 ) 2 SbCl 5 (imidazolium cation) with the cis modification of the [MX 5 ] 2− ∞ chains. 5,6,10 The ferroelectric PTs taking place in (MV)BiBr 5 and (H 2 dmdap)SbCl 5 are connected mainly to a significant distortion of regular trans-and cis-connected octahedra ('displacive' contribution), leading to strong polar polyanionic substructures.…”

Nontoxic (CH3NH3)3Bi2I9 perovskite solar cells free of hole conductors with an alternative architectural design and a solution-processable approach

“…Recent studies have demonstrated that 0D Bi-based compounds [12][13][14][15][16][17][18] with the chemical formula (CH 3 NH 3 ) 3 Bi 2 I 9 (MBI) are suitable for photosensitive layer in solar cells. [19][20][21][22][23][24][25][26][27] Bi-Based perovskites have been previously subjected to experimental and theoretical analyses.…”