Thermally and Photoinduced Spin-Crossover Behavior in Iron(II)-Silver(I) Cyanido-Bridged Coordination Polymers Bearing Acetylpyridine Ligands.

We report two new cyanido-bridged Fe(II)-Ag(I) coordination polymers using different acetylpyridine isomers, {Fe(4acpy)[Ag(CN)]} and {Fe(3acpy)[Ag(CN)]} (4acpy = 4-acetylpyridine; 3acpy = 3-acetylpyridine) displaying thermally and photoinduced spin crossover (SCO). In both cases, the acetylpyridine ligand directs the coordination polymer structure and the SCO of the materials. Using 4-acetylpyridine, a two-dimensional (2D) structure is observed in made of layers stacked on each other by silver-ketone interactions leading to a complete SCO and reversible thermally and photoswitching of the magnetic and optical properties.

[(CH)NH]PdBr, a layered hybrid halide perovskite semiconductor with improved optical and electrical properties.

Inspired by the success of three-dimensional hybrid perovskites (CHNH)PbX (X = Cl, Br, I), two-dimensional (2D) organic-inorganic hybrid metal halides have drawn immense attention due to their highly tunable physical properties. Moreover, although 3D hybrid perovskite materials have been reported, the development of new organic-inorganic hybrid semiconductors is still an area in urgent need of investigation. Here, we used the dimethylammonium cation to construct a palladium-based halide perovskite material [(CH)NH]PdBr with a 2D layered structure.

Supramolecular Frameworks Based on Rhenium Clusters Using the Synthons Approach.

The reaction of the K[{ReS}(OH)]·8HO rhenium cluster salt with pyrazine (Pz) in aqueous solutions of alkaline or alkaline earth salts at 4 °C or at room temperature leads to apical ligand exchange and to the formation of five new compounds: [{ReS}(Pz)(OH)(HO)] (), [{ReS}(Pz)(OH)(HO)] (), (NO)[{ReS}(Pz)(OH)(HO)](Pz)·3HO (), [Mg(HO)][{ReS}(Pz)(OH)(HO)]·8.5HO (), and K[-{ReS}(Pz)(OH)(HO)]·8HO (). Their crystal structures are built up from - or -[{ReS}(Pz)(OH)(HO)] cluster units.

Retraction: Ni[LnCl] (Ln = Eu, Ce, Gd): the first Ln compounds stabilized in a pure inorganic lattice.

Retraction of 'Ni2[LnCl6] (Ln = EuII, CeII, GdII): the first LnII compounds stabilized in a pure inorganic lattice' by Bianca Baldo et al., Chem. Commun.

Rational synthesis and dimensionality tuning of MOFs from preorganized heterometallic molecular complexes.

Rational synthesis of a series of new heterometallic MOFs was carried out by the judicious choice of the corresponding pivalate complexes [Li2M2(piv)6(py)2] (M = Zn2+, Co2+, piv- = pivalate anion and py = pyridine) as a source of secondary building units, {LiM(O2CR)3} and an organic tricarboxylate linker as a node defining the dimensionality of the framework by the orientation of the carboxylic group in or out of the central aromatic ring plane. Thus the trimesate (btc3-) linker results in 3D srs topology frameworks with intersecting systems or isolated channels, and 1,3,5-benzenetribenzoate (btb3-) results in layered hcb isostructural compounds additionally stabilized with H-π interactions between the layers. The layered compounds demonstrate a permanent porosity with a BET surface area of up to 688 m2·g-1 with the possibility of selective gas adsorption (CO2 over N2 and CH4).

Metal Atom Clusters as Building Blocks for Multifunctional Proton-Conducting Materials: Theoretical and Experimental Characterization.

The search for new multifunctional materials displaying proton-conducting properties is of paramount necessity for the development of electrochromic devices and supercapacitors as well as for energy conversion and storage. In the present study, proton conductivity is reported for the first time in three molybdenum cluster-based materials: (H)[MoBrS(OH)]-12HO and (H)[MoX(OH)]-12HO (X = Cl, Br). We show that the self-assembling of the luminescent [MoL(OH)] cluster units leads to both luminescence and proton conductivity (σ = 1.

Thermal and Guest-Assisted Structural Transition in the NH₂-MIL-53(Al) Metal Organic Framework: A Molecular Dynamics Simulation Investigation.

Reversible structural transition between the Large (LP) and Narrow Pore (NP) forms (breathing phenomena) of the MIL-53(X, X = Al, Cr, Fe, Ga) Metal Organic Framework (MOF) is probably one of the most amazing physical properties of this class of soft-porous materials. Whereas great attention has been paid to the elucidation of the physical mechanism ruling this reversible transition, the effect of the functionalization on the flexibility has been less explored. Among functionalized MIL-53(Al) materials, the case of NH2-MIL-53(Al) is undoubtedly a very intriguing structural transition rarely observed, and the steadier phase corresponds to the narrow pore form.

Ni[LnCl] (Ln = Eu, Ce, Gd): the first Ln compounds stabilized in a pure inorganic lattice.

Here we report the first examples of 3d-4f compounds based on LnII cations. We have obtained a series of Ni2[LnCl6] isostructural compounds where LnII = Ce 1, Eu 2 and Gd 3 which were characterized in a cubic crystalline system with a Fm3[combining macron]m space group. Magnetic and optical characterization was also performed on this new class of compounds.

Stabilization of Ni dimers in hexacyano Mo cluster-based Prussian blue derivatives: experimental and theoretical investigations of magnetic properties.

Herein, two new octahedral molybdenum cyanide cluster compounds, namely [{Ni(NH)}{Ni(NH)}][MoBrQ(CN)]·12HO, Q = S (1) and Se (2), have been synthesized as single crystals by slow diffusion of a solution of nickel chloride into aqueous ammonia solutions of a KCs[MoBrQ(CN)] molybdenum cyanide cluster-based compound. Both 1 and 2 were structurally characterized by single-crystal X-ray diffraction. They are isostructural and crystallize in the cubic system (Im3[combining macron]m (no.

First copper(ii) phase M'0.2Mn0.8PS3·0.25H2O and analogous M' = Co(II), Ni(II) and Zn(II) materials obtained by microwave assisted synthesis.

M'0.2Mn0.8PS3·0.

Superstructure of a substituted zeolitic imidazolate metal-organic framework determined by combining proton solid-state NMR spectroscopy and DFT calculations.

We report the supercell crystal structure of a ZIF-8 analog substituted imidazolate metal-organic framework (SIM-1) obtained by combining solid-state nuclear magnetic resonance and powder X-ray diffraction experiments with density functional theory calculations.

Effect of co-existing ions during the preparation of alumina by electrolysis with aluminum soluble electrodes: structure and defluoridation activity of electro-synthesized adsorbents.

The electrochemical dissolution of aluminum was carried out to prepare hydrated aluminas which were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), chemical titrations and defluoridation activities. Aluminas were obtained at controlled pH depending upon the counter cations of the electrolyte. A boehmite AlOOH phase was isolated mainly in ammonium solution, while aluminas synthesized in the other media contained a mixture of phases, usually both boehmite and bayerite γ-Al(OH)₃.

DFT-assisted structure determination of α1- and α2-VOPO4: new insights into the understanding of the catalytic performances of vanadium phosphates.

Structural investigations on vanadium phosphates, which are extensively used as catalysts in industry, often resulted in important advances in the understanding of the mechanisms driving the catalytic oxidation of light hydrocarbons. Layer translations in the two lamellar vanadium phosphates α1- and α2-VOPO4 phases identified during the catalysis were investigated by the combination of first-principles calculations, synchrotron X-ray powder diffraction, single-crystal X-ray diffraction and solid-state NMR. This analysis reveals an important feature: the α1-form is the only polymorph of VOPO4 to exhibit layer translations that prevent the formation of infinite VO6 chains.

A second monoclinic polymorph of ethyl-enediammonium bis-(hydrogen squarate) monohydrate.

The title compound, C(2)H(10)N(2) (2+)·2HC(4)O(4) (-)·H(2)O, a new polymorph of ethyl-enediammonium bis-(hydrogen squarate) monohydrate, was synthesized by slow evaporation of an acid solution. The asymetric unit contains two hydrogen squarate anions, two half-mol-ecules of protonated ethyl-enediamine arranged around a twofold axis and one water mol-ecule. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds between the hydrogen squarate anions, protonated N atoms from the amine group and water mol-ecules lead to a three-dimensional framework.

Yttrium ethyl-enediammonium squarate tetra-hydrate.

The title compound, {(C(2)H(10)N(2))(1.5)[Y(C(4)O(4))(3)(H(2)O)(4)]}(n) {system-atic name: catena-poly[sesqui(ethyl-enediammonium) [[tetra-aquabis-(squarato-κO)yttrium(III)]-μ-squarato-κ(2)O:O']]}, was synthesized by slow evaporation of an acid solution. The asymetric unit contains one yttrium cation in an anti-prismatic environnement, three squarate groups, one and a half protonated ethyl-enediamine mol-ecules and four water mol-ecules.

VOPO4·H2O: a stacking faults structure studied by X-ray powder diffraction and DFT-D calculations.

The dehydration process of VOPO(4)·2H(2)O occurs in two steps corresponding to successive elimination of the two crystallographically distinct water molecules. The intermediate phase VOPO(4)·H(2)O has been stabilized for X-ray powder diffraction studies. The resulting data suggest a tetragonal cell (a = 6.

A monoclinic pseudopolymorph of manganese squarate dihydrate, Mn(mu-C(4)O(4))(H(2)O)(2), built from cubic units.

The structure of poly[[[hexaaquatrimanganese(II)]-tri-mu-squarato] monohydrate], {[Mn(3)(C(4)O(4))(3)(H(2)O)(6)].H(2)O}(n), synthesized hydrothermally, consists of a new three-dimensional framework described by secondary building units (SBUs) containing two MnO(6) octahedra and three squarate groups in a cube-shaped arrangement. In the asymmetric unit, one squarate group is located around an inversion centre (4a; 0, 0, 0), two Mn atoms [4d (3/4, 1/4, 0) and 4c (1/4, 1/4, 0)] are located on inversion centres and the third Mn atom is on a twofold axis (4e; 0, y, 1/4).

The Kagomé topology of the gallium and indium metal-organic framework types with a MIL-68 structure: synthesis, XRD, solid-state NMR characterizations, and hydrogen adsorption.

The vanadium-based terephthalate analogs of MIL-68 have been obtained with gallium and indium (network composition: M(OH)(O(2)C-C(6)H(4)-CO(2)), M = Ga or In) by using a solvothermal synthesis technique using N,N-dimethylformamide as a solvent (10 and 48 h, for Ga and In, respectively, at 100 degrees C). They have been characterized by X-ray diffraction analysis; vibrational spectroscopy; and solid-state (1)H and (1)H-(1)H radio-frequency-driven dipolar recoupling (RFDR), (1)H-(1)H double quantum correlation (DQ), and (13)C{(1)H} cross polarization magic angle spinning (CPMAS) NMR spectroscopy. The three-dimensional network with a Kagomé-like lattice is built up from the connection of infinite trans-connected chains of octahedral units MO(4)(OH)(2) (M = Ga or In), linked to each other through the terephthalate ligands in order to generate triangular and hexagonal one-dimensional channels.

New 3pi-2spiro ladder-type phenylene materials: synthesis, physicochemical properties and applications in OLEDs.

New routes to ladder-type phenylene materials 1 and 2 are described. The oligomers 1 and 2, which possess a "3pi-2spiro" architecture, have been synthesized by using extended diketone derivatives 3 and 10 as key intermediates. The physicochemical properties of the new blue-light emitter 2 were studied in detail and compared with those of the less-extended 1.

Structural and luminescent properties of micro- and nanosized particles of lanthanide terephthalate coordination polymers.

Reaction in water between rare earth ions (Ln = Y, La-Tm, except Pm) and the sodium salt of terephthalic acid leads to a family of lanthanide-based coordination polymers of general formula [Ln2(C8H4O4)3(H2O)4] n with Ln = La-Tm or Y. The isostructurality of the compounds with the previously reported Tb-containing polymer is ascertained on the basis of their X-ray powder diffraction diagrams. The coordination water molecules can be reversibly removed without destroying the crystal structure for compounds involving one of the lighter lanthanide ions (La-Eu).

Dispirofluorene-indenofluorene derivatives as new building blocks for blue organic electroluminescent devices and electroactive polymers.

A series of new dispiro[fluorene-9',6,9'',12-indeno[1,2b]fluorenes] (DSF-IFs) has been synthesised. These new building blocks for blue-light-emitting devices and electroactive polymers combine indenofluorene (IF) and spirobifluorene (SBF) properties. We report here our synthetic investigations towards these new structures and their thermal, structural, photophysical and electrochemical properties.

Investigation of acid sites in a zeotypic giant pores chromium(III) carboxylate.

A study of the zeotypic giant pores chromium(III) tricarboxylate Cr(III)3OF(x)(OH)(1-x)(H2O)2 x {C6H3-(CO2)3}2 x nH2O (MIL-100) has been performed. First, its thermal behavior, studied by X-ray thermodiffractometry and infrared spectroscopy, indicates that the departure of water occurs without any pore contraction and no loss in crystallinity, which confirms the robustness of the framework. In a second step, IR spectroscopy has shown the presence of three distinct types of hydroxy groups depending on the outgassing conditions; first, at high temperatures (573 K), only Cr-OH groups with a medium Brønsted acidity are present; at lower temperatures, two types of Cr-H2O terminal groups are observed; and at room temperature, their relatively high Brønsted acidity allows them to combine with H-bonded water molecules.

Very large swelling in hybrid frameworks: a combined computational and powder diffraction study.

Using a combination of simulations and powder diffraction, we report here the study of the very large swelling of a three-dimensional nanoporous iron(III) carboxylate (MIL-88) which exhibits almost a reversible doubling (approximately 85%) of its cell volume while fully retaining its open-framework topology. The crystal structure of the open form of MIL-88 has been successfully refined and indicates that atomic displacements larger than 4 angstroms are observed when water or various alcohols are adsorbed in the porous structure, revealing an unusually flexible crystallized framework. X-ray thermodiffractometry shows that only a displacive transition occurs during the swelling phenomenon, ruling out any bond breaking.

MIL-103, a 3-D lanthanide-based metal organic framework with large one-dimensional tunnels and a high surface area.

A lanthanide-based metal organic framework, formulated Tb(C27H15O6)(H2O).2C6H11OH, has been solvothermally synthesized using the extended rigid tritopic ligand 1,3,5-tribenzoate. Included free solvent could be removed upon heating, and the resulting material presents large 1-D micropores (free diameter = 10 A) and a high surface area (SLangmuir > 1000 m2.