2,2'-bithiophene derivatives, 5-ammoniumethylsulfanyl-2,2'-bithiophene (AESBT) and 5,5'-bis(ammoniumethylsulfanyl)-2,2'-bithiophene (BAESBT), have been designed for their incorporation in organic-inorganic materials based on iodometalates. Three layered compounds, (BAESBT)PbI(4), (AESBT)(4)Pb(3)I(10), and (AESBT)(3)Bi(2)I(9), have been synthesized as crystals from slowly cooled aqueous solution containing metal halide and bithiophene derivative salts. When starting from the diammonium cation, (BAESBT)PbI(4) hybrid perovskite is obtained. (BAESBT)PbI(4) adopts a triclinic cell (P1) with the lattice parameters a = 8.4741(5) A, b = 8.9255(6) A, c = 16.876(1) A, alpha = 88.328(5) degrees, beta = 81.806(4) degrees, gamma = 88.864(5) degrees, Z = 2. In the structure, PbI(4)(2)(-) perovskite sheets and diammonium cation layers alternate along c. The incorporation of the corresponding monoammonium cation (AESBT) leads to a head to tail arrangement of the molecules in the (AESBT)(4)Pb(3)I(10) hybrid, precluding the formation of the perovskite layers. (AESBT)(4)Pb(3)I(10) is orthorhombic, Pna2(1), with a = 38.333(4) A, b = 22.239(3) A, c = 8.448(2) A, Z = 4. The structure consists of corrugated layers of Pb(3)I(10)(4)(-) separated by organic layers of monoammonium cations. A similar relative situation of molecules in organic layers is observed in (AESBT)(3)Bi(2)I(9), with the inorganic sheets being built up from Bi(2)I(9)(3)(-) entities. (AESBT)(3)Bi(2)I(9) crystallizes in an orthorhombic cell (P2(1)2(1)2(1)) with a = 8.4564(6) A, b = 21.368(2) A, c = 30.747(2) A, Z = 4. In the three compounds, the molecular packings appear different, underlining the interplay between both organic and inorganic components. New packings are stabilized, as illustrated by an original mixed kappa-alpha type arrangement of the bithiophene units in (AESBT)(3)Bi(2)I(9). Furthermore, molecular interactions, especially of S.S type, appear stronger in the hybrids based on the monoammonium cations. The electrical conductivity of a (BAESBT)PbI(4) single crystal has also been investigated, revealing a semiconductive behavior with a characteristic energy of E(g) = 2.535 eV.

The first hybrid perovskites incorporating alcohol-based bifunctional ammonium cations, (HO(CH(2))(2)NH(3))(2)PbX(4) (X = I, Br), have been prepared and characterized. (HO(CH(2))(2)NH(3))(2)PbI(4) adopts a monoclinic cell, a = 8.935(1) A, b= 9.056(2) A, c = 10.214(3) A, beta = 100.26(1) degrees , V = 813.3(3) A(3), P2(1)/a, and Z = 2, and (HO(CH(2))(2)NH(3))(2)PbBr(4) is orthorhombic, a = 8.4625(6) A, b = 8.647(1) A, c = 19.918(2) A, V = 1457.5(2) A(3), Pbcn, and Z = 4. In the layered structures, a unique hydrogen-bond network connects adjacent perovskite layers, owing to OH....X, NH(3)(+)....X, and intermolecular NH(3)(+)...OH interactions. Its impact on the bonding features of the inorganic framework and on the quite short interlayer distance, in the case of (HO(CH(2))(2)NH(3))(2)PbI(4), is shown. As a result, a significant red shift of the exciton peaks (lambda = 536 nm (X = I), lambda = 417 nm (X = Br)), compared to other PbX(4)(2)(-)-based perovskite hybrids, is observed, revealing a reduced band gap. A reversible structural transition occurs at T = 96 degrees C (X = I) and T = 125 degrees C (X = Br). An orthorhombic cell of the high-temperature phase of (HO(CH(2))(2)NH(3))(2)PbI(4) with a(HT) = 18.567(6) A, b(HT) = 13.833(6) A, c(HT) = 6.437(2) A, and V = 1653 A(3) is proposed from powder X-ray diffraction. A change in the hydrogen bonding occurs, with molecules standing up in the interlayer space and OH parts probably interacting together, leading to a more conventional situation for ammonium groups and a more distorted perovskite layer. This is in accordance with the blue shift of the exciton peak to lambda = 505 nm (X = I) or to lambda = 374 nm (X = Br) during the phase transition.

The reaction of cobalt, nickel, copper and cadmium chlorides and bromides with 5-methylfurfural thiosemicarbazone (M5FTSC) leads to the formation of two series of new complexes: [M(M5FTSC) 2 X 2 ], [M(M5FTSC)X 2 ]. They have been characterized by spectroscopic studies (infrared, 1 H NMR, and electronic spectra). The crystal structures of the free ligand M5FTSC and of the compound [CuCl 2 (M5FTSC)] have been determined by X-ray diffraction methods. For the Co(II), Ni(II) and Cu(II) complexes, the central atom is coordinated through the sulphur atom and the azomethine nitrogen atom whilst for the Cd(II) complexes, the coordination atoms are the sulphur and furanic oxygen atoms instead of the azomethine nitrogen.

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The synthesis and characterization of new modified tetrathiafulvalenes (TTF), the S-position isomers of BEDT-TTF and EDT-TTF, are described. The synthetic strategy presented in this work is based on an efficient and unprecedented two-step sequence for the conversion of a vicinal bis(hydroxymethyl) functionality into a disulfide ring. Different routes are discussed in terms of efficiency for the synthesis of the symmetric S-position isomer of BEDT-TTF and that of EDT-TTF. Their electrochemical properties are combined with data obtained from UV/Vis spectroscopy and orbital calculations, and the electronic influence of peripheral sulfur atoms on the neutral and oxidized species is discussed. The introduction of these outer sulfur atoms at the periphery of the TTF core gives rise to specific intermolecular S...S interactions in the corresponding organic materials. Crystallographic studies of radical cation salts synthesized upon electrocrystallization clearly showed that the network obtained is dictated by the outer sulfur atoms, which are responsible for a characteristic and unprecedented "windmill" array.

Synthesis of single crystals of Cd(OH)Cl and Cu(OH)Cl allowed us to revise the structure of these hydroxychlorides and con5rm their space group: P6 3 mc (R ‫؍‬ 0.041; R w ‫؍‬ 0.050) for Cd(OH)Cl and P2 1 /c (R ‫؍‬ 0.051; R w ‫؍‬ 0.069) for Cu(OH)Cl. Positions of hydrogen atoms were determined and an hypothesis of hydrogen bonds is discussed in relation to the infrared spectra.A comparison of the structures shows that an isomorphism is not possible between the two compounds, due to the important Jahn+Teller e4ect of divalent copper. On the other hand, a structural relationship exists between Cd(OH)Cl and -Cd(OH) 2 , which belongs to the brucite-type family. Academic Press

The analysis of the crystal structure of (C4H3SCH2NH3)2(CH3NH3)Pb2I7, displaying a well-ordered acentric inorganic Pb2I7(3-) bilayer, is reported, and compared to the related monolayer hybrid perovskite.

Bridged dithienylethylenes (DTEs) bearing solubilizing alkyl chains at various positions (2-5) have been synthesized by McMurry dimerization of cyclopenta[b]thiophen-6-ones. In order to introduce alkyl substituents at different positions of the DTE molecule, the precursor ketones have been prepared by different strategies based on a combination of Mannich or Wittig-Horner reaction and Friedel-Craft intramolecular cyclization. The position and the length of the alkyl substituents exert a strong effect on the ability of the precursor to undergo electrochemical polymerization. Thus, whereas substitution at the alpha-position of the ethylene linkage (3) results in a rapid inhibition of electropolymerization, introduction of alkyl chains at the beta-position (4, 5) greatly improves the efficiency of the polymerization process. The analysis of the electrochemical and optical properties of the polymers shows that rigidification of the DTE molecule leads to a significant decrease of the oxidation potential and bandgap. A comparative analysis of DTE and its bridged analogues by means of X-ray diffraction reveals, in agreement with experimental and theoretical results, that the observed reduction of both the HOMO-LUMO gap of the precursor and the bandgap of the corresponding polymers are related to a relaxation of bond length alternation in the DTE moiety.