Crystal Structure,Thermal and Electric Behaviour of [(CH3)2NH2]3[As2Cl9] and [(CH3)2NH2][AsOCl2]

Single crystals of the organic‐inorganic arsenate(III): [(CH₃)₂NH₂]₃[As₂Cl₉] and [(CH₃)₂NH₂][AsOCl₂] have been grown from aqueous hydrochloric acid solution. The crystals [(CH₃)₂NH₂]₃[As₂Cl₉] have been investigated by X‐ray diffraction (at 253 K), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dilatometric and dielectric methods. They undergo two structural phase transitions of first order at 228/235 and 298/307 K (on cooling/heating), respectively, which are classified as an "order‐disorder" type. The trigonal [(CH₃)₂NH₂]₃[As₂Cl₉] structure (at 253 K, intermediate phase (II)) refined in the space group R3c, consists of isolated [As₂Cl₉]^3‐ bioctahedral units and dimethylammonium cations hydrogen bonded to the bridging Cl atoms of the anions. The crystals of [(CH₃)₂NH₂][AsOCl₂] at 100 K are orthorhombic, space group Cmca. The structure contains one‐dimensional chains formed by strong distorted [AsO₂Cl₄] octahedra. The dimethylammonium cations reveal distinct disorder.     

Synthesis and Characterization of [NH3（CH2）2NH2（CH2）2NH3]BiCl6

1 INTRODUCTION During the past decade, a series of organic-inor- ganic hybrid compounds based on metal halide units have been prepared and studied[1]. The combination of organic and inorganic components at the mole- cular level affords us the opportunity to design new hybrid materials and modulate the properties of components[2]. As a result, some interesting proper- ties, such as non-linear optical[3], interesting magne- tic[4], efficient luminescence[2], ideal thermal and mechanical sta…     

Isotype Strukturen einiger Hexaamminmetall(II)-halogenide von 3d-Metallen: [V(NH3)6]I2, [Cr(NH3)6]I2, [Mn(NH3)6]Cl2, [Fe(NH3)6]Cl2, [Fe(NH3)6]Br2, [Co(NH3)6]Br2 und [Ni(NH3)6]Cl2

The Structures of some Hexaammine Metal(II) Halides of 3 d Metals: [V(NH₃)₆]I₂, [Cr(NH₃)₆]I₂, [Mn(NH₃)₆]Cl₂, [Fe(NH₃)₆]Cl₂, [Fe(NH₃)₆]Br₂, [Co(NH₃)₆]Br₂ and [Ni(NH₃)₆]Cl₂ Crystals of yellow [V(NH₃)₆]I₂ and green [Cr(NH₃)₆]I₂ were obtained by the reaction of VI₂ and CrI₂ with liquid ammonia at room temperature. Colourless crystals of [Mn(NH₃)₆]Cl₂ were obtained from Mn and NH₄Cl in supercritical ammonia. Colourless transparent crystals of [Fe(NH₃)₆]Cl₂ and [Fe(NH₃)₆]Br₂ were obtained by the reaction of FeCl₂ and FeBr₂ with supercritical ammonia at 400°C. Under the same conditions orange crystals of [Co(NH₃)₆]Br₂ were obtained from [Co₂(NH₂)₃(NH₃)₆]Br₃. Purple crystals of [Ni(NH₃)₆]Cl₂ were obtained by the reaction of NiCl₂ · 6H₂O and NH₄Cl with aqueous NH₃ solution. The structures of the isotypic compounds (Fm3 m, Z = 4) were determined from single crystal diffractometer data (see “Inhaltsübersicht”). All compounds crystallize in the K₂[PtCl₆] structure type. In these compounds the metal ions have high-spin configuration. The orientation of the dynamically disordered hydrogen atoms of the ammonia ligands is discussed.     

Metallampullen als Mini‐Autoklaven: Synthese und Kristallstrukturen der Ammoniakate [Al(NH3)4Cl2][Al(NH3)2Cl4] und (NH4)2[Al(NH3)4Cl2][Al(NH3)2Cl4]Cl2

Metal Ampoules as Mini‐Autoclaves: Syntheses and Crystal Structures of [Al(NH₃)₄Cl₂][Al(NH₃)₂Cl₄] and (NH₄)₂[Al(NH₃)₄Cl₂][Al(NH₃)₂Cl₄]Cl₂ The salts [Al(NH₃)₄Cl₂]⁺[Al(NH₃)₂Cl₄]^–≡AlCl₃ · 3 NH₃ ( 1 ) and (NH₄⁺)²[Al(NH₃)₄Cl₂]⁺[Al(NH₃)₂Cl₄]^–(Cl^–)₂≡ AlCl₃ · 3 NH₃ · (NH₄)Cl ( 2 ) have been obtained as single crystals during the reactions of aluminum and aluminum trichloride, respectively, with ammonium chloride in sealed Monel metal containers. The crystal structure of 1 was determined again [triclinic, P‐1; a = 574.16(10); b = 655.67(12); c = 954.80(16) pm; α = 86.41(2); β = 87.16(2); γ = 84.89(2)°], that of 2 for the first time [monoclinic, I2/m; a = 657.74(12); b = 1103.01(14); c = 1358.1(3) pm; β = 103.24(2)°].     

Structural Characterization of trans-[Cr(NH3)4(H2O)Cl]Cl2 and trans-[Cr(NH3)4Cl2]l

Trans-[Cr(NH₃)₄(H₂O)Cl]Cl₂ (A) crystallizes in the monoclinic space group P2₁/m (No. 11) with a = 6.556(1), b = 10.630(5), c = 6.729(2) Å and β = 96.15(3)°. Trans-[Cr(NH₃)₄Cl₂]I (B) has monoclinic C2/m (No. 12) space group and a = 9.877(2), b = 8.497(2), c = 6.047(2) Å and β = 108.98(2)°. Both unit cells contain two formula units. Cr? Cl, Cr? O(H₂O) and three independent Cr? N(NH₃) distances for A are 2.98(1), 2.023(2), 2.067(2), 2.086(3) and 2.064(3) °. Cr? Cl and Cr? N(NH₃) bonds in B are 2.325(1) and 2.071(2) °. All octahedral angles are close to 90 and 180°. Both structures were refined to very low R values. Water molecule from trans-[Cr(NH₃)₄(H₂O)Cl]²⁺ is hydrogen bonded to both ionic chlorides. Cation and two anions form the motive which repeats itself in the crystal. Cations and anions of the second structure are distributed in layers. Each cation and anion have coordination number eight.     

Thermal decomposition of [Co(NH3)5Cl]Cl2

Simultaneous TG-DTG-DTA studies on [Co(NH₃)₅Cl]Cl₂ under non-isothermal conditions were carried out in dynamic air and argon atmospheres in the temperature range 293–1273 K. Thermogravimetric measurements under quasi-isothermal conditions were also made. On the basis of the experimental data (weight loss, X-ray diffraction, reflectance spectroscopy and chemical analysis), the probable decomposition sequences are presented. The data indicate that the thermal decomposition of [Co(NH₃)₅Cl]Cl₂ occurs in three stages in argon and four stages in air.The changes in the morphology of crystalline [Co(NH₃)₅Cl]Cl₂ powder in the course of its thermal decomposition in air were followed by scanning electron microscopy.

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Zusammenfassung In dynamischer Luft- und ArgonatmosphÄre wurden im Temperaturbereich 293–1273 K unter nichtisothermen Bedingungen simultane TG-DTG-DTA Untersuchungen an [Co(NH₃)₅Cl]Cl₂ durchgeführt, ebenso auch thermogravimetrische Untersuchungen unter quasi-isothermen Bedingungen. Auf der Grundlage der experimentellen Daten (Gewichtsverlust, Röntgendiffraktion, Reflexionsspektroskopie und chemische Analyse) wurde eine wahrscheinliche Zersetzungssequenz erstellt. Es zeigte sich, da\ die thermische Zersetzung in Argon in drei Schritten, in Luft dagegen in vier Schritten verlÄuftDie VerÄnderung der Morphologie kristallinen [Co(NH₃)₅Cl]Cl₂-Pulvers im Verlaufe seiner thermischen Zersetzung in Luft wurde durch Scanning-Elektronenmikroskopie verfolgt.

     

Thermal decomposition of [Co(NH3)5Cl]Cl2

The thermal decomposition of [Co(NH₃)₅Cl]Cl₂ was studied under non-isothermal conditions, in dynamic air and argon atmospheres. The kinetics of the particular stages of [Co(NH₃)₅Cl]Cl₂ thermal decomposition were evaluated from the dynamic weight loss data by means of the modified Coats-Redfern method. TheD _n andR _n models were selected as the models best fitting the experimental TG curves. These models suggest that the kinetics and macromechanism of [Co(NH₃)₅Cl]Cl₂ decomposition can be governed by diffusive and/or phase boundary processes. The values of the activation energy,E _a, and the pre-exponencial factor,A, of the particular stages of the thermal decomposition were calculated.     

A novel chain-like molybdenum phosphate: hydrothermal synthesis,crystal structure and characterization of [NH3(CH2CH2)2NH3]3[NH3(CH2CH2)2NH2]-Na5[Mo6O12(OH)3(PO4)(HPO4)3]2·4H2O

A novel organic/inorganic hybrid molybdenum phosphate, [NH₃(CH₂CH₂)₂NH₃]₃[NH₃(CH₂CH₂)₂NH₂]Na₅-[Mo₆O₁₂(OH)₃(PO₄)(HPO₄)₃]₂·4H₂O (1), involving molybdenum presented in V oxidation, has been hydrothermally prepared and characterized by elemental analysis, i.r., u.v.–vis., x.p.s., t.g. and single crystal X-ray diffraction. The structure of the title compound (1) may be considered to consist of two [Mo₆O₁₂(OH)₃(PO₄)(HPO₄)₃] units bonded together with NaO₆ octahedra, forming dimers. Further, these dimers connect with each other through four Na⁺ cations as bridges, giving rise to novel one-dimensional chain-like skeleton. Piperazines exist among inorganic chains acting as charge balancing cations.     

Thermal decomposition of the [Co(NH3)6]Cl3, Co[(NH3)4Cl2]Cl,K3[Fe(C2O4)3]3H2O and Fe(CH3COO)3 in argon and air atmosphere

Kinetic parameters (apparent activation energy, reaction order, pre-exponential factor (Z) in the Arrhenius equation) for thermal decomposition of the [Co(NH₃)₆]Cl₃, Co[(NH₃)₄Cl₂]Cl, K₃[Fe(C₂O₄)₃]3H₂O and Fe(CH₃COO)₃ are reported. They have been calculated on the DTA and TG data according to Coats-Redfern's model. Both, decomposition data obtained in argon and in air atmosphere have been considered and the results are compared.

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Zusammenfassung Es werden die kinetischen Parameter (scheinbare Aktivierungsenergie, Reaktionsordnung, prÄexponentieller Faktor (Z) der Arrhenius-Gleichung) der thermischen Zersetzung von [Co(NH₃)₆]Cl₃, [Co(NH₃)₄Cl₂]Cl, K₃[Fe(C₂O₄)₃]3H₂O und Fe(CH₃COO)₃ beschrieben, die entsprechend dem Coats-Redfern-Modell auf der Basis der DTA- und TG-Daten errechnet wurden. Die Zersetzung wurde sowohl in Argon als auch in Luft durchgeführt und die erhaltenen Daten miteinander verglichen.

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Helpful comments from Professor W. Wojciechowski and financial support from Institute for Low Temperatures and Structure Research Polish Academy of Sciences (CPBP 01.12) are greatefully acknowledged.     

[In2(HPO3)4]·(NH3CH2CH2NH3)的水热合成与晶体结构

用乙二胺作模板剂在水热条件下合成出一个新的三维开放骨架结构的亚磷酸铟[In2(HPO3)4]·(NH3CH2CH2NH3)(1), 并对其晶体结构进行了测定和表征.     

Photogeneration of metastable side-on N2 linkage isomers in [Ru(NH3)5N2]Cl2, [Ru(NH3)5N2]Br2 and [Os(NH3)5N2]Cl2

Photogeneration of side-on N2 linkage isomers in [Ru(NH3)5N2]2+ and [Os(NH3)5N2]2+ is achieved by irradiation with lambda = 325 nm of powder samples at T = 80 K and detected by the downshift of the nu(N-N) vibration and by the heat release at elevated temperature due to the back switching of the side-on configuration to the ground state. The concentration of the transferred molecules is evaluated by the decrease of the area of the nu(N-N) or 2nu(N-N) vibrational bands. All characteristic changes between the linear Ru-N-N and side-on configuration are predicted by DFT calculations: the structure of the anion, shifts of the vibrations, electronic excitation energy, energetic position and sequence of the electronic orbitals, the potentials of the ground and relaxed metastable state with the activation energy, saddle points and energetic position of the minimum.