Pr(OTf)3-promoted Chichibabin pyridine synthesis of isodesmosine in H2O/MeOH

1,2,3,5-Tetrasubstituted pyridinium amino acid isodesmosine is a crosslinking amino acid of elastin and is an attractive biomarker for the diagnosis of chronic obstructive pulmonary disease (COPD). Herein, we report an application of the Chichibabin pyridine synthesis to the total synthesis of isodesmosine. Specifically, the appropriate protected lysine and the corresponding aldehyde were reacted using Pr(OTf)₃ in H₂O/MeOH.     

二维网状有机锑对氨基苯乙酸酯的合成、表征及晶体结构研究

The title complex bis(4-aminophenylacetate)triphenylantimony(V) has been synthesized by the reaction of triphenylantimony dibromide with 4-aminophenylacetic acid in 1∶2 molar ratio. The complex was characterized by elemental analysis, IR spectra, NMR ( ¹H, ¹³C) and X-ray diffraction crystal structure analysis. This complex crystallizes in the monoclinic system, space group C2/c with a=2.279 4(2) nm, b=0.957 10(10) nm, c=1.335 49(15) nm, β=93.781(2)°. The molecular structure adopts a distorted trigonal bipyramidal geometry around the antimony atom. In the crystal structure molecules are connected by intermolecular N-H…O hydrogen-bonding interactions forming a two-dimensional network structure. CCDC: 726039.     

Hydrothermal synthesis of [C6H16N2][In2Se3(Se2)]: A new one-dimensional indium selenide

A new organically templated indium selenide, [C₆H₁₆N₂][In₂Se₃(Se₂)], has been prepared hydrothermally from the reaction of indium, selenium and trans-1,4-diaminocyclohexane in water at 170 °C. This material was characterised by single-crystal and powder X-ray diffraction, thermogravimetric analysis, UV-vis diffuse reflectance spectroscopy, FT-IR and elemental analysis. The compound crystallises in the monoclinic space group C2/c (a=12.0221(16) Å, b=11.2498(15) Å, c=12.8470(17) Å, β=110.514(6)°). The crystal structure of [C₆H₁₆N₂][In₂Se₃(Se₂)] contains anionic chains of stoichiometry [In₂Se₃(Se₂)]²⁻, which are aligned parallel to the [1 0 1] direction, and separated by diprotonated trans-1,4-diaminocyclohexane cations. The [In₂Se₃(Se₂)]²⁻ chains, which consist of alternating four-membered [In₂Se₂] and five-membered [In₂Se₃] rings, contain perselenide (Se₂)²⁻ units. UV-vis diffuse reflectance spectroscopy indicates that [C₆H₁₆N₂][In₂Se₃(Se₂)] has a band gap of 2.23(1) eV.     

Synthesis and structure of three manganese oxalates: MnC2O4·2H2O, [C4H8(NH2)2][Mn2(C2O4)3] and Mn2(C2O4)(OH)2

Three manganese oxalates have been hydrothermally synthesized, and their structures determined by single-crystal X-ray diffraction. MnC₂O₄·2H₂O (I) is orthorhombic, P2₁2₁2₁, , , , , Z=4, final R, R_w=0.0832, 0.1017 for 561 observed data (I>3σ(I)). The one-dimensional structure consists of chains of oxalate-bridged manganese centers. [C₄H₈(NH₂)₂][Mn₂(C₂O₄)₃] (II) is triclinic, , , , , α=81.489(2)°, β=81.045(2)°, γ=86.076(2)°, , Z=1, final R, R_w=0.0467, 0.0596 for 1773 observed data (I > 3σ (I)). The three-dimensional framework is constructed from seven coordinate manganese and oxalate anions. The material contains extra-framework diprotonated piperazine cations. Mn₂(C₂O₄)(OH)₂ (III) is monoclinic, P2₁/c, , , , β=91.10(3)°, , Z=1, final R₁, wR2=0.0710, 0.1378 for 268 observed data (I>2σ (I)). The structure is also three dimensional, with layers of MnO₆ octahedra pillared by oxalate anions. The hydroxide group is found bonded to three manganese centers resulting in a four coordinate oxygen.     

Role of SrMoO4 in Sr2MgMoO6 synthesis

Here we investigate the elemental and phase compositions during the solid-state synthesis of the promising SOFC-anode material, Sr₂MgMoO₆, and demonstrate that molybdenum does not notably evaporate under the normal synthesis conditions with temperatures up to 1200 °C due to the formation of SrMoO₄ as an intermediate product at low temperatures, below 600 °C. However, partial decomposition of the Sr₂MgMoO₆ phase becomes evident at the higher temperatures (∼1500 °C). The effect of SrMoO₄ on the electrical conductivity of Sr₂MgMoO₆ is evaluated by preparing a series of Sr₂MgMoO₆ samples with different amounts of additional SrMoO₄. Under the reducing operation conditions of an SOFC anode the insulating SrMoO₄ phase is apparently reduced to the highly conductive SrMoO₃ phase. Percolation takes place with 20-30 wt% of SrMoO₄ in a Sr₂MgMoO₆ matrix, with a notable increase in electrical conductivity after reduction. Conductivity values of 14, 60 and 160 S/cm are determined at 800 °C in 5% H₂/Ar for the Sr₂MgMoO₆ samples with 30, 40 and 50 wt% of added SrMoO₄, respectively.     

Synthesis, structure and magnetic behavior of a new three-dimensional Manganese phosphite-oxalate: [C2N2H10][Mn2(OH2)2(HPO3)2(C2O4)]

A novel manganese phosphite-oxalate, [C₂N₂H₁₀][Mn₂^II(OH₂)₂(HPO₃)₂(C₂O₄)] has been hydothermally synthesized and its structure determined by single-crystal X-ray diffraction. The structure consists of neutral manganese phosphite layers, [Mn(HPO₃)]_∞, formed by MnO₆ octahedra and HPO₃ units, cross-linked by the oxalate moieties. The organic cations occupy the middle of the 8-membered one-dimensional channels. Magnetic studies indicate weak antiferromagnetic interactions between the Mn²⁺ ions.     

Vapour-liquid equilibrium data for the systems C2H6 + N2, C2H4 + N2, C3H8 + N2, and C3H6 + N2

High pressure vapour-liquid equilibrium data for the C₂H₆ + N₂, C₂H₄ + N₂, C₃H₈ + N₂, and C₃H₆ + N₂ systems are presented. The data are obtained isothermally in the range from 200 K to 290 K. For each point of data, temperature, pressure and liquid and vapour phase mole fractions are measured.Values for the vapour phase mole fractions are calculated from the obtained pressure, temperature and liquid phase mole fractions. The calculated values are compared with the experimental results, and it is found that the average mean deviation between calculated and experimental mole fractions is less than 0.009 for the systems considered in this work.     

Hydrothermal synthesis and structures of the novel niobium phosphates [NbOF(PO4)](N2C5H7) and [(Nb0.9V1.1)O2(PO4)2(H2PO4)](N2C2H10)

Two new niobium phosphates were synthesized and their crystal structures determined from single-crystal X-ray data. [NbOF(PO₄)](N₂C₅H₇) (1) (monoclinic, space group P2₁/c, a=11.442(1), b=9.1983(7), c=9.1696(8) Å, β=109.94(1)°) has a layered structure and is the first example of a negatively charged NbOF(PO₄) layer analogous to the MO(H₂O)PO₄ (M=V, Nb) layers. The layer charge is compensated by interlayer 4-aminopyridnium cations that adopt an unusual arrangement as a consequence of H-bonding and π-π interactions. The interlayer aminopyridnium cations can be exchanged with alkylammonium ions which form bilayers inclined at ∼65° to the NbOF(PO₄) layer. [(Nb_0.9V_1.1)O₂(PO₄)₂(H₂PO₄)] (N₂C₂H₁₀) (2) (orthorhombic, space group Pbca, a=15.821(2),b=9.0295(9),c=18.301(2) Å) has a disordered three-dimensional structure based on NbO(PO₄) layers cross-linked by phosphate tetrahedra, and has a similar structure to the known vanadium analog [V₂O₂(PO₄)₂(H₂PO₄)] (N₂C₂H₁₀).     

Hydrothermal synthesis and structural characterization of two organically templated zincophosphites with three-dimensional frameworks, (C6H14N2)·[Zn3(HPO3)4] and (C4H12N2)·[Zn3(HPO3)4]

Two organically templated zincophosphites, (C₆H₁₄N₂)·[Zn₃(HPO₃)₄] and (C₄H₁₄N₂)·[Zn₃(HPO₃)₄] have been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction. (C₆H₁₄N₂)·[Zn₃(HPO₃)₄] crystallizes in the triclinic space group , with cell parameters, a=9.363(4) Å, b=10.051(4) Å, c=10.051(4) Å, α=85.777(13)°, β=82.091(9)°, and γ=79.783(9)°. (C₄H₁₄N₂)·[Zn₃(HPO₃)₄] crystallizes in the monoclinic space group P2₁/c, with cell parameters, a=9.9512(3) Å, b=10.1508(3) Å, c=17.8105(5) Å, and β=95.6510(10)°. Although the two structures are different, they have the same anionic framework compositions of [Zn₃(HPO₃)₄]²⁻. Their frameworks are built up from strictly alternating ZnO₄ tetrahedra and HPO₃ pseudo pyramids by sharing vertexes. There exist channels with an eight-membered ring window along the a- and c-axis. Powder X-ray diffraction, IR spectroscopy, ³¹P MAS solid-state NMR, thermogravimetric and differential thermal analyses were also carried out.     

锡(Ⅳ)N,N-二取代荒酸配合物Ph3SnS2CN(CH3)C6H5、 Ph3SnS2CN(C4H8NH)和SnCl2(S2CNEt2)2的合成、表征及晶体结构

Three tin (Ⅳ) complexes with N,N-dialkyl dithiocarbamates Ph₃SnS₂CN(CH₃)C₆H₅ (1),Ph₃SnS₂CN(C₄H₈NH) (2) and Sn(Cl)₂(S₂CNEt₂)₂ (3) have been synthesized. The crystal structures have been determined by X-ray sin- gle crystal diffraction. A crystal of the complex 1 is triclinic with space group P1, a=0.9485(3)nm, b=1.0491(3)nm, c=1.3631(4)nm, α=70.996(4)°, β=72.294(4)°, γ=79.609(4)°, Z=2, V=1.2168(6)nm³, D_c=1.453g·cm^-3, μ=1.234mm^-1, R=0.0442, wR=0.0858. A crystal of the complex 2 is monoclinic with space group P2(1)/c, a=1.2214(2)nm, b=1.1651(2)nm, c=1.5769(3)nm,β=99.039(2)°, Z=2, V=2.2162(7)nm³, D_c=1.532g·cm^-3, μ=1.352mm^-1, R=0.0267, wR=0.0591. A crystal of the complex 3 is triclinic with space group P1, a=0.7179(2)nm, b=0.9256(3)nm, c=1.5327(5)nm,α=93.857(4)°,β=98.992(4)°, γ=109.481(4)°, Z=2, V=0.9405(5)nm³, D_c=1.717g·cm^-3, μ=2.076mm^-1, R=0.0263, wR=0.0662. In the complexes 1 and 2 the tin atoms rendered five-coordination in a distorted tigonal bipyramidal structure and in the complex 3 the tin atom rendered six-coordination in a distorted octahedron structure. CCDC: 1, 179918; 2, 180024; 3, 180004.     

Gallium tri-chloride derivatives of the sterically demanding pyridines 2,6-Ar2C6H3N (Ar = 2,4,6-Me3C6H2 or 2,4,6-Pr3C6H2)

The sterically demanding pyridines 2,6-Ar₂C₆H₃N [Ar = 2,4,6-Me₃C₆H₂ (1) or 2,4,6-Prⁱ₃C₆H₂ (2)] were prepared by a palladium catalysed Kumada C–C coupling reaction in high yield. Pyridine 1 reacted with one equivalent of GaCl₃ to afford the tetra-chloro gallate–pyridinium ion pair complex [GaCl₄]⁻[2,6-(2,4,6-Me₃C₆H₂)₂C₆H₃NH]⁺ (3). Contrastingly, pyridine 2 reacted with one equivalent of GaCl₃ to afford the anticipated donor-acceptor complex [GaCl₃{2,6-(2,4,6-Prⁱ₃C₆H₂)₂C₆H₃N}] (4). Complexes 1–4 have been characterised variously by single crystal X-ray diffraction, NMR, CHN, and mass spectrometry.     

Solvothermal synthesis and characterisation of new one-dimensional indium and gallium sulphides: [C10N4H26]0.5[InS2] and [C10N4H26]0.5[GaS2]

Two new main group metal sulphides, [C₁₀N₄H₂₆]_0.5[InS₂] (1) and [C₁₀N₄H₂₆]_0.5[GaS₂] (2) have been prepared solvothermally in the presence of 1,4-bis(3-aminopropyl)piperazine and their crystal structures determined by single-crystal X-ray diffraction. Both compounds are isostructural and crystallise in the monoclinic space group P2₁/n (Z=4), with a=6.5628(5), b=11.2008(9), c=12.6611(9) Å and β=94.410(4)° (wR=0.035) for compound (1) and a=6.1094(5), b=11.2469(9), c=12.7064(10) Å and β=94.313(4)° (wR=0.021) for compound (2). The structure of [C₁₀N₄H₂₆]_0.5[MS₂] (M=In,Ga) consists of one-dimensional [MS₂]⁻ chains which run parallel to the crystallographic a axis and are separated by diprotonated amine molecules. These materials represent the first example of solvothermally prepared one-dimensional gallium and indium sulphides.     

Synthesis and crystal structures of (C8h8)Nd(C5H9C5H4) (THF)2 and [(C8H8)Gd(C5H9C4H4(THF)][(C8H8)GD(C5H9C5H4(THF)2]

LnCl₃ (Ln=Nd, Gd) reacts with C₅H₉C₅H₄Na (or K₂C₈H₈) in THF (C₅H₉C₅H₄ = cyclopentylcyclopentadienyl) in the ratio of 1 : to give (C₅H₉C₅H₄)LnCl₂(THF)_n (orC₈H₈)LnCl₂(THF)_n], which further reacts with K₂C₈H₈ (or C₅H₉C₅H₄Na) in THF to form the litle complexes. If Ln=Nd the complex (C₈H₈)Nd(C₅H₉C₅H₄)(THF)₂ (a) was obtained: when Ln=Gd the 1 : 1 complex [(C₈H₈)Gd(C_%H₉)(THF)][(C₈H₈)Gd(C₅H₉H₄)(THF)₂] (b) was obtained in crystalline form.

The crystal structure analysis shows that in (C₈H₈)Ln(C₅H₉C₅H₄)(THF)₂ (Ln=Nd or Gd), the Cyclopentylcyclopentadieny (η⁵), cyclooctatetraenyl (η⁸) and two oxygen atoms from THF are coordinated to Nd³⁺ (or Gd³⁺) with coordination number 10.

The centroid of the cyclopentadienyl ring (Cp′) in C₅H₉C₅H₄ group, cyclooctatetraenyl centroid (COTL) and two oxygens (THF) form a twisted tetrahedron around Nd³⁺ (or Gd³⁺). In (C₈H₈)Gd(C₅H₉C₅H₄)(THF), the cyclopentyl-cyclopentadienyl (η⁵), cyclooctatetraenyl (η⁸) and one oxygen atom are coordinated to Gd³⁺ with the coordination number of 9 and Cp′, COT and oxygen atom form a triangular plane around Gd³⁺, which is almost in the plane (dev. -0.0144 Å).     

Hydrothermal synthesis and characterization of the first 1-D indiumphosphate chain In2(HPO4)2(H2PO4)2F2·C4N2H12, a precursor for high dimensional structures

The first one-dimensional (1-D) indiumphosphate chain, In₂(HPO₄)₂(H₂PO₄)₂F₂·C₄N₂H₁₂ (1), has been hydrothermally prepared using piperazine (PIP) as a template. The structure consists of infinite chains of trans,trans-corners-sharing InO₄F₂ octahedra with the adjacent octahedra being bridged by tetrahedral PO₃(OH) and PO₂(OH)₂ units, which are H-bonded with amine groups of the organic cations. Interestingly, this macroanionic chain InP₂O₈H₃F⁻ is similar to that found in the mineral tancoite-like chains and has potential to further set up higher-dimensional networks. On heating 1 in the presence of additional phosphoric acid at 180 °C under hydrothermal condition, compound 2, In₂(OH)(H₂O)(PO₄)₂·H₃O·H₂O, possessed a 3-D structure building from the repetition of a secondary building unit is obtained. When 1 is heated with additional PIP, an unknown phase, compound 3 is formed. Finally, on treatment with another amine, such as diethylenetriamine or 1,4-diaminobutane, at 180 °C, 1, as a precursor, can convert into a previously known 3-D framework structure with 16-membered ring compound 4. Compounds 1 and 2 are determined by single-crystal X-ray diffraction. Furthermore, 1 is characterized by X-ray powder diffraction, IR spectroscopy, inductively coupled plasma analysis, thermogravimetric analysis and differential thermal analysis.     

配合物Zn(C3H4N2)2(C8H6O2Br)2的水热合成、晶体结构及性质

在140℃下,以3-溴-4-甲基苯甲酸和咪唑为配体,通过水热法在甲醇/水混合溶剂中反应24 h合成了锌(Ⅱ)配合物Zn(C3H4N2)2(C8H6O2Br)2。通过元素分析、红外光谱、热重分析和X射线粉末衍射对配合物进行了结构表征,同时用X射线单晶衍射分析确定了其晶体结构。结果表明,其晶体属单斜晶系,空间群为C2/c,晶胞参数:a=13.257(3),b=9.765(2),c=20.494(4),β=107.79(3)°,V=2526.3(9)3,Dc=1.655g·cm-3,μ=4.170mm-1,F(000)=1248,Z=4,最终残差因子R1=0.0552,wR2=0.1378。配合物为单核结构,中心锌(Ⅱ)离子与来自2个3-溴-4-甲基苯甲酸根的2个O原子及2个咪唑分子的2个N原子配位,形成了畸变的四方锥几何体。晶体内,分子间则通过N—H…O氢键作用在ab面形成了层状结构。研究了配合物的发光性质。     

Synthesis and spectral characterization of diorganodiaminosilanes [(ArNH)2SiPhMe] (Ar = 2,6-Pr2C6H3; 2,4,6-Me3C6H2) and lithium silylamide [(2,6-Et2C6H3NLi)(2,6-Et2C6H3NH)SiPh2]

Aminosilanes bearing bulky substituents on nitrogen centers, [(ArNH)₂SiPhMe] (Ar = 2,6-ⁱPr₂C₆H₃ (1), 2,4,6-Me₃C₆H₂ (2)) and half-sandwich lithium silylamide [(2,6-Et₂C₆H₃NLi)(2,6-Et₂C₆H₃NH)SiPh₂] (3) have been prepared and characterized by elemental analysis, IR, EI mass and NMR (¹H and ²⁹Si) spectroscopic studies. The solid state structures of 2 and 3 have been determined by single crystal X-ray diffraction studies. The molecule 2 has a C₁ symmetry due to the steric crowding, and the two N-H protons are approximately trans to each other. The amido nitrogen atoms in 2 show significant deviation from trigonal-planar geometry, and as a result, the observed Si-N bonds are marginally longer than those observed in aminosilanes with planar nitrogen atoms. The molecule 3 exists as discrete dimer with an inversion center. The Li ion in 3 forms intramolecular π-complex with the neighboring aryl (2,6-Et₂C₆H₃) group, to form a half-sandwich lithium silylamide.     

Inorganic-organic hybrid materials: synthesis and crystal structure determination from powder diffraction data of Pb2(O3PCH2C6H4CH2PO3)

A new lead diphosphonate, Pb₂(O₃PCH₂C₆H₄CH₂PO₃) was hydrothermally synthesized from tetraethyl α,α′-p-xylenediphos-phonate and Pb(NO₃)₂. The structure was solved and refined using X-ray powder diffraction data. It crystallizes in the monoclinic space group P2₁/c, with a = 467.84(2), b = 2007.98(9), c = 639.10(2) pm, β = 101.020(3)°, V = 589.31(4) 10⁶ pm, Z=2, wR_p=0.034, R_p=0.027, R_F2=0.061, R_F=0.036. The structure is built from corner-linked [PbO₄] polyhedra, containing a lone pair of electrons. These polyhedra are connected to layers by phosphonate groups, RPO₃²⁻ and through the organic diphosphonic acid to a three-dimensional structure. Thermogravimetric as well as IR spectroscopic studies are also presented.     

新型一维链状配位聚合物[Cd2(C23H14O6)2(C10H9N3)2(H2O)]n的研究

配位超分子聚合物的设计合成与应用研究一直是配位化学、超分子化学、生物无机化学及材料科学等领域的热点研究课题之一,具有微孔结构的配位聚合物吸引了许多科学家的目光,这不仅因为该类配合物具有新颖的结构,展现出多种诱人的拓扑结构,更主要的 是因为它们在离子交换、催化、磁性材料、光学材料及气体贮存领域的应用潜力[1～3].