首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The structure of the diammonium salt of 5-nitraminotetrazole wasestablished bysinglecrystalX-ray diffraction. The crystals are monoclinic, space group P2/c; a=7.272(1), b=8.643(1), c=10.427(1) ; =93.20(1)°; V=654.33(39) 3; Z=4;calc=1.666 g/cm3. The dianion is nonplanar, but contains two practically planar fragments -- the tetrazole cycle and the nitramine group. The ammonium cations form an extended net of hydrogen bonds with the dianions, involving all hydrogen atoms. The negative charges of the dianion are located on the nitro oxygen atoms and the nitrogens of the tetrazole cycle. The difference between the geometrical parameters of the compound and those of other 5-nitraminotetrazole salts is examined.  相似文献   

2.
The crystal and molecular structures of a guest–host complex of cucurbituril with 4methylpyridinium, {(4MePyH) (C36H36N24O12)}(NO3) · 4H2O, were determined by Xray structural analysis. The crystals are monoclinic with a = 26.276(3) , b = 25.861(2) , c = 17.375(2) , = 124.17(1)°, Vcell =9768.6(18) 3, space group Cc, and Z = 8. The structure contains two crystallographically independent supramolecular complexes. They are arranged in pillars oriented along the a axis. In each pillar, the complexes are parallel to each other. The pillars are shifted with respect to each other by onehalf of the crystallographic translation. The centers of the supermolecules are arranged according to a pseudobodycentered motif. Distortions of the cucurbituril molecule depending on the guest type have been analyzed with the use of results obtained in the present and previous studies.  相似文献   

3.
The results of structural studies of the synthetic analog of the radtkeite mineral Hg3S2Cl1.00I1.00 are analyzed. The crystal structure of the compound has been refined; the unit cell parameters are a m = 16.827(4) , b m = 9.117(1) , c m = 13.165(5) , = 130.17(2)°, V = 1543.3(8) 3, space group C2/m, Z = 8, R = 0.0527. A possible transition a 0 = a m; b 0 = a m + 2c m; c 0 = –b m to the pseudo-orthorhombic F cell previously determined for radtkeite, where one of the angles ( 0 ) is slightly different from 90° (89.55°), has been found. Each sulfur atom in the structure is bonded to three mercury atoms, forming SHg3 umbrellas with distances 2.240(6) –2.474(8) and angles HgSHg 94.7(2)°–102.9(2)°. The SHg3 fragments are linked through Hg vertices to form corrugated [Hg12S8] layers. The halogen atoms lie inside and between the [Hg12S8] layers; the distances are Hg-Cl and Hg-I 2.783(7) , 2.961(7) , and 3.083(4) –3.311(3) , respectively.Original Russian Text Copyright © 2004 by N. V. Pervukhina, S. V. Borisov, S. A. Magarill, D. Yu. Naumov, V. I. Vasiliev, and B. G. NenashevTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 755–758, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.  相似文献   

4.
Xray structural investigation of the monoammonium salt of 5nitroaminotetrazole was performed. The crystals are orthorhombic: a = 10.077(1), b = 17.009(1), c = 6.6472(6), V = 1139.33(17)3, space group Pbca, Z =8, calc = 1.715 g/cm3. Monodeprotonation of 5nitroaminotetrazole during formation of the salt occurs at the N(4) nitrogen atom of the heterocycle. The anion has an almost flat structure; the bond lengths suggest delocalization of electron density in the molecule. The negative charge is distributed among three nitrogen atoms and two oxygen atoms of the anion. Changes in the geometrical parameters of 5nitroaminotetrazole on monodeprotonation are considered.  相似文献   

5.
Singlecrystal Xray analysis was employed to study dehydrated wairakite Ca0.97Na0.06K0.03×[Al1.95Si4.04O12] with the following parameters: a = 18.260(4) , b = 18.284(4) , c = 13.432(3) , = 90.28(3)°, V = 4989(3) 3, Z = 16, space group B21/d. A comparison was carried out with the structure of the hightemperature (600°) phase, space group I41/acd. The coordination of the Ca cations increased from 4 to 4 + 1. Additional ligands were acquired from the fourmember ring of the framework upon its deformation and a pairwise countershift of the cations along the c axis. This resulted in a pseudotetragonal unit cell with a doubled volume and lowered symmetry.  相似文献   

6.
An Xray structural investigation of 2nitro1ureidoguanidine has been carried out. The crystals are monoclinic: a = 4.4690(2), b = 15.566(1), c = 9.4131(7), = 94.896(5)°, V = 652.4(3)> 3, space group P21/n, Z = 4, calc = 1.650 g/cm3. The molecule consists of two planar fragments: carbamide and nitroguanidine. The geometrical characteristics of the molecule are analyzed. The system of intra and intermolecular hydrogen bonds in the crystal is considered.  相似文献   

7.
Crystal structures of two new compounds containing trigonal tellurium-bridged cluster fragments [Mo3(3-Te)(2-Te2)3]4+ were investigated. Crystal data for K4.5{[Mo3(3-Te)(2-Te2)3(CN)6]I}I1.5·3H2O: space group , Z = 4, a = 13.280(1), c = 23.800(3) , V = 3635.0(6) 3, d calc = 3.432 g/cm3, R 1 = 0.0335, wR2 = 0.0912 for 1378 I hkl > 2 I from 3545 measured I hkl ; for Cs3{[Mo3(3-Te)(2-Te2)3(CN)6]I}·2H2O: space group P2 1 /n, Z = 2, a= 9.650(2) , b = 22.297(5), c = 27.446(7) , = 94.10(2)°, V = 5890(2) 3, d calc = 4.273 g/cm 3, R 1 = 0.0384, wR 2 = 0.0744 for 957 I hkl > 2 I from 3758 measured I hkl (Enraf-Nonius CAD-4 diffractometer, MoK , graphite monochromator). In both compounds, ionic pairs {[Mo3Te7(CN)6]I}3– with Teax...I distances of 3.358-3.676 are formed. In the potassium salt, the {[Mo3Te7(CN)6]I}3– anion pairs are linked by the additional TeeqI short contacts of 3.460 into two-dimensional corrugated layers perpendicular to the c axis of the unit cell. The structure of the cesium salt is ionic with interstitial H2O molecules and double-layer closest packing of anions.  相似文献   

8.
The crystal structures of two polysulfide phases HoS1.885(5) (I) and HoS1.863(8) (II) were determined; the integer stoichiometric ratio was found to be Ho8S15. The data were collected on an Enraf-Nonius CAD-4 automatic diffractometer using the standard procedure (MoK, graphite monochromator, an absorption correction applied based on -scan data). Crystal I: space group P4/nmm, a = 3.820(1), c = 7.840(3) , V = 114.40(6) 3, Z = 2 for the composition HoS1.885(5), d calc = 6.542 g/cm3, R = 0.0520 for 184 unique reflections with Ihkl > 2 I; crystal II: space group P21/m, a = 10.961(2), b = 11.465(2), c = 10.984(2) , = 91.27(3)°, V = 1380.0(4) 3, Z = 24 for the composition HoS1.863(8), d calc = 6.486 g/cm3, R = 0.0596 for 5354 unique reflections with Ihkl > 2 I. In both compounds, the Ho atoms are surrounded by 9 (8+1 for three atoms in II) S atoms forming monocapped square antiprisms. The Ho–S distances vary from 2.717 to 3.067 irrespective of the type of ion [S2– or (S2)2–]; the maximal distance to the atoms completing the coordination is 3.684 . The compounds have PbFCl type structures composed of ...(S2)2–...Ho3+...S2–...S2–...Ho3+...(S2)2–... layer packets differently oriented in space relative to the unit cell axes. The S2–...S2– and S2–...(S2)2– interlayer distances are mostly shorter than the sum of the ionic radii and vary within the limits of 3.331-3.558 and 3.029-3.784 for the first and second types, respectively. For I, the calculated site occupancies and densities are given depending on the composition Ho-S2-x (x = 0.25-0); for II, the most probable formulas of rational compositions in the same range of x are presented.  相似文献   

9.
Crystals of the ionic complex (salt) of 4,7,13,16,21,24hexaoxa 1,10diazabicyclo[8.8.8]hexacozane perchlorate, [H2(Crypt2.2.2)]2+ · 2ClO4 -, were synthesized and studied by Xray structural analysis: space group C2/c, a = 20.198(3), b = 10.119(2), c = 12.938(2), = 90.97(1)°, Z = 4, 3030 measured independent reflections, R = 0.067. In these crystals, all atoms of the 2.2.2 dication are disordered over two positions with occupancies of 0.518(4) and 0.482(4). Two conformations of the disordered 2.2.2 dication are such that two H atoms at two nodal N atoms point to its cavity.  相似文献   

10.
Single crystals of K5(Cd0.5Zr1.5)2(MoO4)6 molybdate have been grown. Its composition and crystal structure have been established from Xray diffraction data CAD4 automatic diffractometer, MoK radiation, 940 F(hkl), R = 0.0234. The crystals have a trigonal unit cell a = b = 10.624(1), c = 37.694(6), V = 3684.5(8)3, and space group R3c. The 3D mixed framework of the molybdate structure is formed by two kinds of Mo tetrahedra and (Cd, Zr) octahedra joined by shared O vertices. The large cavities in the framework are occupied by K atoms of three kinds. The distribution of Cd2+ and Zr4+ cations over two crystallographic positions has been refined.  相似文献   

11.
Novel anhydrous trinuclear 3-oxo complexes of Cr(III), Cr3(3-O)(CF3COO)6(CH3COOH)2(CF3COO) (I) and of Cr(III,III,II), Cr3(3-O)(CF3COO)6(CH3COOH)2(THF) (II) (where THF is (CH2)4O) are synthesized by anodic dissolution of metallic chromium in solutions of trifluoroacetic acid in acetonitrile and in tetrahydrofuran and their structures are studied by X-ray diffraction analysis. Complex I forms orthorhombic crystals with space group Pna21, a = 9.778(1) , b = 16.042(2) , c = 22.851(4) , Z = 4, R 1 = 0.0332; complex II crystallizes in monoclinic system: space group P21/c, a = 9.866(1) , b = 17.895(2) , c = 21.167(4) , = 100.75(2)°, Z = 4, R = 0.0422. The average Cr-(3-O) distances in compounds I and II are almost equal (1.943(3) and 1.927(3) ). An average length of the Cr-O bond in octahedral surrounding of metal atoms is different in complexes I and II (1.985(4) and 2.003(3) , respectively), which is specified by different oxidation states of the metal atom. The CrCr distances lie in an interval of 3.366(1)–3.337(1) .__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 4, 2005, pp. 266–272.Original Russian Text Copyright © 2005 by Glazunova, Boltalin, Troyanov.  相似文献   

12.
The binary complex salt [Rh(NH3)5Cl][PtBr6] was synthesized and studied by Xray structural analysis. The crystallographic data are as follows: a = 12.013(2) , b = 8.401(2) , c = 15.999(3) , = 91.13(3)°, V = 1614.3(6) 3, space group P21/m, Z = 4, dx = 3.70 g/cm3, R = 0.086. The thermal decomposition of the salt in a hydrogen atmosphere is shown to produce a Rh0.5Pt0.5 solid solution with an FCC cell [a = 3.864(2) . The thermal decomposition of the salt in a helium atmosphere proceeds via the formation of metallic Pt and RhBr3 and finally results in a mixture of several solid solutions.  相似文献   

13.
Single crystals of [Ni(Phen)(iBu2PS2)2] (I) and [Ni(Phen)3](iBu2PS2)2 (III) compounds were grown, and their structures were determined by Xray diffraction analysis (CAD4 diffractometer, MoK radiation, 3336 F hkl , R = 0.0373 for I and 2575 F hkl for III). The crystals of complex I have a triclinic unit cell with the following parameters: a = 11.097(1) , b = 14.903(2) , c = 22.650(3); = 75.18(1)°, = 80.50(1)°, = 75.07(1)°, V = 3479.2(7)3, Z = 4, calc = 1.255 g/cm3, and space group 1; the crystals of III have a monoclinic unit cell with the following parameters: a = 19.010(3), b = 15.481(1) , c = 17.940(3); = 97.58(1)°, V = 5233.5(12)3, Z = 4, calc = 1.292 g/cm3, and space group C2/c. The structure of complex I is built from mononuclear molecules, and the structure of III, from [Ni(Phen)3]2+ complex cations and i Bu2PS2 - outersphere anions. The NiN2S4 coordination polyhedra in the structure of I and NiN6 in the structure of III are distorted octahedra. Based on structural data, the interaction between the coordinated Phen molecules of complexes I, [Ni(Phen)2(iBu2PS2)](iBu2PS2) (II), and III is considered, as well as the packing modes of these complexes.  相似文献   

14.
4-Amino-1,2,4-triazol-5-one hydrate (ATO·H2O) was prepared and its structure was analyzed by four-circle diffraction measurement. The obtained results show that the crystal belongs to the triclinic crystal system, space group P 1 with crystal parameters a = 6.432(1), b = 6.551(1), c = 6.740(1) ; = 68.04(1), = 82.18(1), = 81.90(1)°, V = 259.7(7) 3; Z = 2; Dc = 1.510 g/cm3; = 0.131 mm-1; F(000) = 124. ATO·H2O was characterized by FT-IR analysis, X-ray diffraction analysis, and single crystal diffraction analysis.  相似文献   

15.
An X-ray structure analysis of 1-(p-tolyl)-4-[4-(N-naphthalimido)butyl]piperazine (I) was carried out: a=9.551(3), b=13.775(3), á=8.917(4) , =103.96(3), =101.47(4), =92.60(3)°, V=1110.4(7) 3, Z=2,calc=1.279 g/cm3, =0.644 mm, space group P 1, 4239 nonzero reflections, R=0.056. The molecule is linear elongated. The p-tolyl and naphthalimide fragments are almost planar, while the piperazine cycle has a chair conformation. The long well-packed molecules form parallel and antiparallel chains with van der Waals interactions between them.  相似文献   

16.
Crystals of the Cs+ Pic (B15C5) complex (Pic=picrate; B15C5=benzo-15-crown-5) (M r =629.3) are yellow prisms which belong to the triclinic space groupP witha=7.377(4),b=11.372(2),c=14.806(2) , =90.31(1), =91.06(2), =108.32(2)0,Z=2,D x =1.77, andD m =1.77 g cm–3. FinalR=0.055 for 3575 observed reflections out of a total of 4004 measured reflections. Cesium forms a 1:1 anion paired complex with B15C5 like sodium rather than a charge separated sandwich structure as found for potassium and expected for cesium in view of the ion-cavity radius concept. The Cs cation is 9-coordinate involving the five crown oxygens (Cs...O, 3.00(1) to 3.24(1) ), the phenoxide (Cs...O, 3.03(1) ) and anortho nitro group oxygen (Cs...O, 3.01(1) ) of the picrate counteranion and, uniquely, with two additional oxygens (Cs...O, 3.17(1) and 3.40(1) ) from apara nitro group of the picrate belonging to the adjacent molecule in the lattice. The Cs+ ion lies 2.07 out of the mean plane formed by the crown oxygens. This system provides the first structural evidence that the interaction stoichiometry of an alkali cation with a cyclic multidentate ligand is not a function of the ion and cavity size alone but also of its Lewis acid strength as modified by the charge neutralizing anion. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82027.  相似文献   

17.
The crystal and molecular structure of [Au(C14H22N4)]Br has been determined. Monoclinic crystals, a=12.592(2), b=6.309(1), c=19.628(2) ; =98.00(1)°, V=1544.1(4) 3, Z=4, dcalc=2.251 g/cm3, space group C2/c. The structure consists of virtually planar centrosymmetric [Au(C14H22N4)]+ cations and Br- anions. The coordination sphere of the gold atom involves four nitrogen atoms of the ligands, forming a planar square. The Au–N bond lengths are equal (the mean length is 1.982(7) ). The C–C and C–N bonds inside the -diiminate rings are delocalized. The parameters of the -diiminate rings of the [Au(C14H22N4)]+ cation are compared with the parameters of the related complexes.  相似文献   

18.
Dianilinegossypol forms a 1 : 2 host-guest complex with DMSO:monoclinic, space group P21/n, a = 8.522(3), b = 18.034(4), c= 28.462(6) , = 94.14(2)°, V = 43623, Z = 4, D x = 1.26 g cm-3, T = 295 K.Final R value is 0.102 for 1793 observed reflections. A 1 : 1 : 1 adduct ofdianilinegossypol with 1,4-dioxane and 1,2-dichloroethane is found to beisostructural with the dianilinegossypol complex with DMSO: monoclinic,space group P21/n, a = 8.281(2), b = 19.245(3), c = 27.970(7), = 95.18°, V = 4439 3, Z = 4, D x =1.28 g cm-3, T = 295 K. Final R value is 0.114 for 2458observed reflections.The host molecules are associated by O(4)—H ...O(3) H-bonds toinfinite chains running in the direction of the c-axis The chains areincorporated into layers through 1,4-dioxane or DMSO molecules havingH-bonds with dianilinegossypol molecules. Another DMSO or 1,2-dichloroethanemolecule is included as a guest in the channels formed between the layers.At 60 °C a cryptate-type inclusion complex of dianilinegossypol isformed with DMSO or 1,4-dioxane. It is isostructural with the acetonecomplex reported in Part IV of the present series.  相似文献   

19.
The reaction between methyl 2-diphenylmethylenehydrazino-4-oxo-4-p-tolyl-2-butenic ether and oxalyl chloride gave 1-diphenylmethyleneamino-5-methoxycarbonyl-4-p-toluoyl-2,3-dihydro-2,3-pyrroledione, which adds water to yield substituted 3,5-dihydroxy-2,5-dihydro-2-pyrrolone. The crystal and molecular structure of pyrrolone and the inter- and intramolecular hydrogen bonds in its crystals and solutions were investigated by IR spectroscopy and XRD analysis. The crystals of C27H22N2O6 are triclinic with cell dimensions a = 9.8540(10), b = 10.0880(10), c = 13.982(2) , = 69.820(10), = 110.57(10), = 91.350(10)°, V = 1213.8(2) 3, M = 470.47, d calc = 1.287 g/cm3, Z = 2, space group P1. The data were collected on a KM-4 (KUMA DIFFRACTION) diffractometer, 3781 reflections with I> 2 (I). Direct methods, hydrogen atoms localized, least-squares refinement (in an anisotropic approximation for non-hydrogen atoms), R = 0.0454. The crystal is built from the centrosymmetric dimer associates of molecules bonded by strong (2.64 ) intermolecular hydrogen bonds (IMHB) of O–H...O type. The dimer associates are linked by weaker (2.82 ) centrosymmetric IMHB, forming an infinite chain of hydrogen-bonded molecules.  相似文献   

20.
Synthesis and X-ray diffraction study of trans-bis-(2-(methylimino)-4-pentanonato)Cu(II), which is methyl-substituted ketoiminate, is reported. Crystal data for CuN2O2C12H20: a = 7.374(1) , b = 9.171(1) , c = 10.823(2) ; = 96.51(1)°, = 106.12(1)°, = 96.81(1)°, space group P , Z = 2, d calc = 1.38 g/cm3, d exp = 1.37 g/cm3, R = 0.037. The structure is molecular and consists of isolated trans-complexes. The coordination polyhedron of the copper atom is intermediate between the square and tetrahedron; the average distances are Cu-O 1.91 and Cu-N 1.95 , the O-Cu-O and N-Cu-N trans bond angles are 145.5° and 150.3°, respectively. The O-Cu-N chelate angle is 94.6°. The calculated energies of van der Waals intermolecular interactions are compared with the thermogravimetric characteristics of the complex with ketoiminate and copper(II) ethylenediamine-bis-acetylacetonate.Original Russian Text Copyright © 2004 by I. A. Baidina, P. A Stabnikov, A. D. Vasiliev, S. A. Gromilov, and I. K. IgumenovTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 706–712, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号