Zur Synthese und Struktur von 8-Nitro-imidazo [1,2-a]pyridinen

Summary The title compounds were synthesized by reaction of nitroketene aminals with -chlorovinylcarbonyl compounds. The chloromethylene malononitriles1 react with nitromethylenimidazolin (2 a) and -benzimidazoles2 b to yield the 8-nitro-2,3-dihydroimidazo[1,2-a]pyridines3 and the 4-nitropyrido[1,2-a]-benzimidazoles6, both containing an amino group. Analogously, from the special 3-chloro-2-propeniminium salt7 and2 a the imidazopyridine derivative9 was formed. The 3-aryl-3-chloro-2-propeniminium salts10 were converted into the nitro-dihydroimidazo[1,2-a]pyridines11 and the pyrido[1,2-a]benzimidazole12 containing the aryl group by reaction with2 a and2 b, respectively. The structures were investigated by 2-dimensional¹H/¹³C-NMR-spectroscopy.

     

Einkristalle von Y3F[Si3O10] im Thalenit-Typ

Single Crystals of Y₃F[Si₃O₁₀] with Thalenite-Type Structure Colourless, diamond-shaped single crystals of Y₃F[Si₃O₁₀] (monoclinic, P2₁/n; a = 730.38(5), b = 1112.47(8), c = 1037.14(7) pm, β = 97.235(6)°, Z = 4) with thalenite-type structure are obtained upon the reaction of YF₃ with Y₂O₃ and SiO₂ (1 : 4 : 9 molar ratio) in evacuated silica tubes at 700 °C in the presence of CsCl as flux within seven days. The crystal structure consists of triangular [FY₃]⁸⁺ cations and catena-trisilicate anions [Si₃O₁₀]^8–, which exhibit a horseshoe-shape resulting from two vertex-shared terminal [SiO₄] tetrahedra with both staggered and eclipsed conformation relative to the central one. The Y³⁺ cations have coordination numbers of seven plus one (Y1) or seven (Y2 and Y3), but only one F^– anion belongs to each and vice versa, the remainder ligands being oxygen members of [Si₃O₁₀]^8– anions.     

Zur Überwindung von Vorurteilen: Das erste basische Oxoindat,Na26O3[InO4]4

The First Basic Oxoindate: Na₂₆O₃[InO₄]₄ For the first time Na₂₆O₃[InO₄]₄ was obtained by annealing intimate mixtures of Na₂O, CdO and elemental In (molar ratio 3.5:1.0:2.0) in closed Ni-cylinders (30 days, 600°C) in form of yellow single crystals. The structure determination by four circle diffractometer data (MoKα, 921 out of 921 I_o(hkl), R = 2.53, R_w = 2.18%) confirms the space group 143d (cubic) with a = 1 427.37 pm and Z = 4. All kation are surrounded by tetrahedron of O^2?. In³⁺ is coordinated with O(1) and O(2) (without O(3)) only. There are ?isolated”? [InO₄]-tetrahedra. The Madelung Part of Lattice Energy, MAPLE, the Mean Fictive Ionic Radii, MEFIR, Effective Coordination Numbers, ECoN, and Charge Distribution, CHARDI, are calculated.     

Synthese und Kristallstrukturen von (Ph4P)4[Bi8I28], (nBu4N)[Bi2I7] und (Et3PhN)2[Bi3I11] – Iodobismutate mit isolierten bzw. polymeren Anionen

Synthesis and Crystal Structures of (Ph₄P)₄[Bi₈I₂₈], (ⁿBu₄N)[Bi₂I₇], and (Et₃PhN)₂[Bi₃I₁₁] – Bismuth Iodo Complexes with Isolated and Polymeric Anions Solutions of BiI₃ in methanol react with NaI and (ⁿBu₄N)(PF₆) or (Et₃NPh)(PF₆) to form anionic bismuth iodo complexes (ⁿBu₄N)[Bi₂I₇] 1 and (Et₃PhN)₂[Bi₃I₁₁] 2 . In 1 Bi₄I₁₆ units, and in 2 Bi₆I₂₄ units are linked by common I-atoms to onedimensional infinite chains. Reaction of BiI₃ with (Ph₄P)(PF₆) in methanol yields (Ph₄P)₄[Bi₈I₂₈] 3 . The anions of 1–3 consist of edge-sharing BiI₆ octahedra. (ⁿBu₄N)[Bi₂I₇] 1 : Space group I2/m (No. 13), a = 1 082.3(5), b = 2 597.1(13), c = 1 206.1(6) pm, β = 93.17(2)°, V = 3 385(3) · 10⁶ pm³; (Et₃PhN)₂[Bi₃I₁₁] 2 : Space group P1 (No. 2), a = 1 283.5(6), b = 1 345.9(7), c = 1 546.3(8) pm, α = 83.87(2), β = 74.24(2), γ = 68.26(2)°, V = 2 388(2) · 10⁶ pm³; (Ph₄P)₄[Bi₈I₂₈] 3 : Space group P1 (No. 2), a = 1 329.3(4), b = 1 337.0(4), c = 2 193.1(5) pm, α = 104.20(2), β = 99.73(2), γ = 100.44(2)°, V = 3 622(2) · 10⁶ pm³.     

Nd4Ti9O24: Präparation und Struktur

Preparation and Crystal Structure of Nd₄Ti₉O₂₄ The compound Nd₄Ti₉O₂₄ was prepared by heating mixtures of Nd₂O₃/TiO₂ (1 : 4.5) at temperatures of T = 1 330°C in air (2× 1d). Single crystals of Nd₄Ti₉O₂₄ were obtained by chemical transport reaction (T₂→T₁; T₁ = 1000°C, T₁ = 900°C, 14 d) using chlorine (p(Cl₂, 298 K) = 1 atm) as transport agent with Nd₄Ti₉O₂₄ as starting material. Nd₄Ti₉O₂₄ crystallizes in the orthorhombic space group Fddd (No. 70) with a = 13.9926(11) Å, b = 35.2844(21) Å, c = 14.4676(17) Å (Z = 16). The structure was refined to give R = 4.0% and R, = 3.7%. Main building units are TiO₆ octahedra, NdO₆ distorted square antiprisms and NdO₆ octahedra.     

Synthese,Eigenschaften und Struktur von oktamerem Titanimidchlorid [Ti(NSiMe3)Cl2]8

Synthesis, Properties, and Structure of Octameric Titanium Imide Chloride [Ti(NSiMe₃)Cl₂]₈ The reaction of TiCl₄ with N(SiMe₃)₃ in sealed glas-tubes yields the titanium imide chloride [Ti(NSiMe₃)Cl₂]₈ ( 1 ). It crystallizes in the space group C2/c with a = 2 704.5(4), b = 1 303.9(1), c = 2 205.4(2) pm, β = 112.78(1)°, Z = 4. In 1 six Ti atoms are linked together by chloro and trimethylsilylimido bridges to form a ring structure. Two TiCl₂-groups are bound in addition to the ring by two imido bridges. Upon annealing at 250°C 1 transformes to the isomeric polymer [Ti(NSiMe₃)Cl₂]_n. Above 250°C 1 decomposes under separation of Me₃SiCl affording TiNCl.     

Two New Modifications of [P(C6H5)4]2[Cu2I4]

Single crystals of two new modifications of [P(C₆H₅)₄]₂[Cu₂I₄] were obtained by reaction of granulated copper with iodine and [P(C₆H₅)₄]I in dry acetone under nitrogen atmosphere. They crystallise monoclinically, space group P2₁/n (No. 14), a = 11.550(6), b = 7.236(2), c = 27.232(13) Å, β = 98.13(3)°, V = 2253(2) ų, and Z = 2 ([P(C₆H₅)₄]₂[Cu₂I₄]-C), and space group Cc (No. 9), a = 17.133(5), b = 15.941(5), c = 18.762 (6) Å, β = 114.02(1)°, V = 4681(3) ų, and Z = 4 ([P(C₆H₅)₄]₂[Cu₂I₄]-D), respectively. In these compounds the [CuI₂]^? anions form dimers di-μ-iodo-diiodocuprate(I), which are either planar ( C ) or folded ( D ).     

稀土钬及铒钇丙氨酸配合物的量热与热分析研究

合成了两种固态稀土丙氨酸配合物[Ho2(Ala)4(H2O)8]Cl6和[ErY(Ala)4(H2O)8](ClO4)6 (Ala为丙氨酸),用量热和热分析方法研究了这两种配合物的热力学性质.用全自动高精密绝热量热计测定了在78～377 K温区内的低温热容.对于[Ho2(Ala)4(H2O)8]Cl6,在214～255 K温区内发现一固-固相变,其相变温度为235.09 K.对于[ErY(Ala)4(H2O)8](ClO4)6,在99～121 K温区内也发现一固-固相变,其相变温度为115.78 K. [Ho2(Ala)4(H2O)8]Cl6固-固相变焓为3.02 kJ• mol－1,相变熵为12.83 J•K－1•mol－1； [ErY(Ala)4(H2O)8](ClO4)6 固-固相变焓为1.96 kJ•mol－1,相变熵为16.90 J•K－1•mol－1.同时,用TG技术在40～800 ℃温区研究了两配合物的热稳定性.由TG/DTG曲线分析可知, [Ho2(Ala)4(H2O)8]Cl6从80 ℃到479 ℃热分解分两步完成, [ErY(Ala)4(H2O)8](ClO4)6从120 ℃到430 ℃热分解分三步完成.     

Organic clays. Synthesis and structure of Na5[calix[4] arene sulfonate] · 12 H2O,K5[calix[4]arene sulfonate]·8 H2O,Rb5[calix[4]arene sulfonate]·5 H2O,and Cs5[calix[4] arene sulfonate] ·4 H2O

The title calixarenes all exist in the solid state as bilayers of anionic calixarenes in the cone configuration. These layers alternate with inorganic regions which contain the cations and the water molecules. The overall structures bear a close resemblance to those found for clay minerals. The sodium salt crystallizes in the triclinic space groupP witha = 10.998(6),b = 13.582(5),c = 14.472(5) Å, = 74.01(3), = 89.09(4), = 86.50(4)°, andZ = 2 forD _calc = 1.72 g cm^–3. Refinement based on 4727 observed reflections led to a conventionalR = 0.050. The potassium salt crystallizes in the triclinic space groupP witha = 11.815(9),b = 13.636(6),c = 14.040(9) Å, = 100.24(5), = 111.86(9), = 95,14(9)°, andZ = 2 forD _calc = 1.77 g cm^–3. Refinement based on 2977 observed reflections led toR = 0.15. The rubidium and cesium salts are isostructural and crystallize in the monoclinic space groupP2₁/n with parameters for Rb[Cs]a = 11.603(5) [11.704(3)],b = 28.607(8) [29.747(9)],c = 12.512(5) [12.604(4)] Å, = 91.70(4) [91.63(2)°], andZ = 4 forD _calc = 2.01 [2.24] g cm^–3. Refinement based on 1750 [4257] observed reflections led toR = 0.108 [0.075]. Disorder of the cations was observed for the rubidium and cesium salts. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82074 (95 pages).     

2-芳基-4-氧-4 H-吡喃酮[3,2-c]-9-溴喹啉类化合物的合成

黄酮类化合物广泛存在于埴物体中,具有广泛的生物活性,其研究发展很快,但对于氮杂黄酮类化合物的研究工作却甚少。含氮黄酮类化合物具有抗癌、抗菌、冠状动脉扩张等作用。但是,目前黄酮类药物仍存在以下问题:(1)黄酮类化合物结构繁多,生物活性极其广泛,但作用强度普遍较弱;(2)黄酮类化合物水溶性较低,影响药物的吸收与疗效。新型黄酮类化合物的合成仍有一定的意义。     

Zur Synthese von 4-Aryl-5,6-dihydro-benzo[h]chinolinen

A new route to the benzo[h]quinoline system3 byMichael-addition of malononitrile to 2-arylidene-1-tetralones1 is presented. The mechanism of this reaction is elucidated by isolation of the intermediate 4H-naphtho[1,2—b]-pyrane2 and its reaction to3. The reaction is proposed to be a sequence of addition, cyclisation,Dimroth-rearrangement and disproportionation.

1. Mitt.:H.-H. Otto, Arch. Pharm. [Weinheim]307, 444 (1974).     

Synthesis and self-assembly of novel calix[4]arenocrowns: formation of calix[4]areno[2]catenanes

A series of novel calix[4]arenocrowns 1a-c were efficiently synthesized by a one-pot reaction of calix[4]monohydroquinone diacetate 5 with ditosylate 6 and its analogues in the presence of sodium hydroxide. It was found that the calix[4]arenocrowns could form stable pseudorotaxane-type complexes 2a-c with paraquat, and further self-assemble into calix[4]areno[2]catenanes 3a-c with dicationic salt 8 and p-bis(bromomethyl)benzene.     

Thiocalix[4] arenes. I. Synthesis and structure of ethylthiocalix[4]arene methyl ether and the related structure of bromocalix[4]arene methyl ether

Bromocalix[4]arene methyl ether serves as a precursor in the synthesis of the title thiocalixarene via the reagent CuSEt. Ethylthiocalix[4]arene methyl ether crystallizes in the monoclinic space groupP2₁/c witha = 20.577(9),b, = 10.722(5),c = 20.315(9) Å, = 120.46(4)°, andD _c = 1.24 g cm^–3 forZ = 4. Refinement based on 1441 observed reflections led toR = 0.080. The configuration of the calixarene lies between the partial cone and the 1,3-altemate conformations. Bromocalix[4]arene methyl ether crystallizes in the triclinic space groupPI witha = 12.283(7),b = 17.658(9),c = 18.118(6) Å, = 90.25(6), = 105.95(4), = 105.11(6)°, andD _c = 1.68 g cm^–3 forZ = 4. Refinement based on 3028 observed reflections led toR = 0.083. The unit cell also contains four CHCl₃ molecules which exist pairwise enclathrated by six calixarenes. The partial cone conformation of the bromocalixarene is identical to that of ethylthiocalix[4]arene methyl ether.     

New preorganized calix[4]arenes. Part I. A doubly-crowned calix and a double-calixcrown derived from 4,6,10,12,16,18,22,24,25,26,27,28-Dodecamethyl-5,11,17,23-tetrahydroxycalix[4] arene

A doubly-crowned calix and a double-calixcrown derived from 4,6,10,12,16,18,22,24,25,26,27, 28-dodecamethyl-5,11,17, 23-tetrahydroxycalix[4]arene (1) have been prepared by reaction of appropriate oligoethylene glycol ditosylates with (1) in acetonitrile in the presence of potassium carbonate. A potassium template effect is observed during one of the double cyclizations.     

Voltammetric behavior of C60-p-tert-butylcalix[8]arene inclusion complex film

The C₆₀-p-tert-butylcalix[8]arene inclusion complex film has been directly formed on the surface of a glassy carbon electrode, and its electrochemical behavior in acetonitrile containing tetra-n-butylammonium hexafluorophosphate as the supporting electrolyte studied. The film has a two-electron reduction wave at −1.0 V (vs Ag/AgCl), but limits to the first cathodic potential scan. Received: 16 September 1997 / Accepted: 27 October 1997     

A new member of the calix[4]crown family:Facile synthesis and characterization of a calix[4]crown-9 cone conformer

25,27-Dipropoxy-p-tert-butylcalix[4]crown-9 cone conformer 5 was readily synthesized via an intramolecular cyclization strategy in good yields.The structures of all the new compounds involved were confirmed by NMR,ESI-MS and elementalanalyses.All of them were proved to be in the cone conformation.     

Azobenzene-bridged calix[8]arenes

An azobenzene bridge was introduced into the lower (or smaller) rim of p-tert-butylcalix[8]arene (1) and 1,5-calix[8]crown-3 (2) to form 1,4-singly bridged (3) and 1,5:3,7-doubly bridged (4) calix[8]arene derivatives, respectively. Trans and cis isomers of conformationally rigid 4 were isolated. The quantum yields of the trans-cis photoisomerisation reactions have been measured.     

Darstellung und Struktur neuer Calix[4]aren-Titan(IV)-Imidokomplexe

Synthesis and Structure of New Calix[4]arene Titanium(IV) Imido Complexes The syntheses of the novel calix[4]arene titanium imido compounds [Cax(OMe)₂O₂Ti(NR)] ( 2 ) (R = tBu) and ( 3 ) (R = Mes = 2,4,6-trimethylphenyl) (Cax = C₄₄H₅₂) starting from [Cax(OMe)₂O₂TiCl₂] ( 1 ) and lithium amides LiNHR are described. Complexes 2 and 3 are mononuclear compounds in solution. An X-ray crystal structure analysis of the toluene adduct of 3 (Space group: P 1, lattice dimensions: a = 12.979(2) Å, b = 13.707(2) Å, c = 16.573(3) Å, α = 81.751(11)°, β = 80.555(13)°, γ = 73.541(12)°) reveals that this compound is mononuclear in the solid state. The central atom in 3 is distorted trigonal bipyramidal ligated by two ether oxygen atoms in axial positions, two phenoxide oxygen atoms in the equatorial plane, and an imido nitrogen atom in an equatorial position. The titanium nitrogen bond distance in 3 is 171.8(3) pm.     

Die Elektronische Struktur von Nb3Br8

The Electronic Structure of Nb₃Br₈ The bonding in Nb₃Br₈ was investigated with the aid of extended Hückel and molecular orbital calculations to gain some understanding concerning stability and possible chemical altering. Seven electrons occupy metal—metal bonding states of a Nb₃Br₈ unit. Six of them are responsible for strong σ bonds within the Nb₃ cluster. One to two additional electrons may be incorporated to occupy a₁ orbitals, which slightly increase the bonding in a Nb₃ cluster, rather than between adjacent clusters.