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 title structures NaGdS2 (sodium gadolinium sulfide), NaLuS2 (sodium lutetium sulfide) and NaYS2 (sodium yttrium sulfide) were redetermined in order to improve the structural information available for the family of group 1 and thallium rare earth sulfides, which are isostructural with the rhombohedral α‐NaFeO2 structure type. In particular, the present investigation has been directed at the rhombohedral sodium rare earth sulfides. The observed dependence of the fractional coordinate z(S2−) on the identity of the rare earth element in the newly determined structures is in agreement with the known structures of the potassium and rubidium analogues. Crystals of NaGdS2 and NaLuS2 display obverse–reverse twinning.  相似文献   

2.
Concentrated aqueous solutions of strontium chloride and barium chloride, respectively, allow on addition of the potassium salt of tetrathiosquarate, K2C4S4·H2O, the isolation of the earth alkaline salts SrC4S4·4 H2O ( 1 ) and Ba4K2(C4S4)5·16 H2O ( 2 ), both as dark red crystals. The crystal structure determinations ( 1 : orthorhombic, Pnma, a = 8.149(1), b = 12.907(2), c = 10.790(2) Å, Z = 4; 2 : orthorhombic, Pbca, a = 15.875(3), b = 21.325(5), c = 16.119(1) Å, Z = 4) show the presence of C4S42− ions with only slightly distorted D4h symmetry having average C–C and C–S bond lengths of 1.41Å and 1.681Å for 1 and 1.450Å and 1.657Å for 2 . The structure of 1 contains concatenated edge‐sharing Sr(H2O)6S2 polyhedra. The Sr2+ ions are in eight‐fold coordination with Sr–O distances of 2.50–2.72Å and Sr–S distances of 3.21Å, (C4S4)2− acts as a chelating ligand towards Sr2+. The structure is closely related to the previously reported Ca2+ containing analogue, which is of lower symmetry belonging to the monoclinic crystal system. A supergroup‐subgroup relation between the space groups of both structures is present. The structure of 2 is made up of Ba2+ and K+ ions in eight and nine‐fold coordination by H2O molecules and (C4S4)2− ions which act as chelating ligands towards one cation and bridging between two cations. The coordination polyhedra of the cations are connected by common edges and corners in two dimensions to layers which are connected by tetrathiosquarate ions to a three‐dimensional network. The infrared and Raman spectra show bands typical for the molecular building units of the two compounds.  相似文献   

3.
The crystal and molecular structures of [Cu(phen)3] Cl2 · CH2Cl2.9H2O (PHEN= 1, 10‐pbenanthroline) have been determined by X‐ray crystallography. The complex crystallizes in triclinic system, space group P1, with lattice parameters a = 1.26000(3), b = 1.37525(4), c = 1.42750(3)nm, α = 85.2970(1),β = 66.8400(1), γ= 83.09(1)°, and Z = 2. The coordinated cations contain a six‐coordinated copper atom chelated by three PHEN ligands, and the Jahn‐Teller effect of the Cu(II) ion results in a distorted octahedral arrangement with the six Cu? N distances ranging from 0.2112(6) to 0.2265(7) nm. In addition to the copper coordinated cation, there are two chloride ions, one dichloromethane solvate and nine water molecules in its asymmetric unit. In the solid state, the title compound forms three dimensional network structures through hydrogen bonds. The intermolecular hydrogen bonds connect the [Cu(phen)3]2+, chloride ion, dichloromethane solvate and H2O moieties altogether.  相似文献   

4.
The scandium(III) cations in the structures of pentaaqua(biuret‐κ2O,O′)scandium(III) trichloride monohydrate, [Sc(C2H5N3O2)(H2O)5]Cl3·H2O, (I), and tetrakis(biuret‐κ2O,O′)scandium(III) trinitrate, [Sc(C2H5N3O2)4](NO3)3, (II), are found to adopt very different coordinations with the same biuret ligand. The roles of hydrogen bonding and the counter‐ion in the establishment of the structures are described. In (I), the Sc3+ cation adopts a fairly regular pentagonal bipyramidal coordination geometry arising from one O,O′‐bidentate biuret molecule and five water molecules. A dense network of N—H...Cl, O—H...O and O—H...Cl hydrogen bonds help to establish the packing, resulting in dimeric associations of two cations and two water molecules. In (II), the Sc3+ cation (site symmetry 2) adopts a slightly squashed square‐antiprismatic geometry arising from four O,O′‐bidentate biuret molecules. A network of N—H...O hydrogen bonds help to establish the packing, which features [010] chains of cations. One of the nitrate ions is disordered about an inversion centre. Both structures form three‐dimensional hydrogen‐bond networks.  相似文献   

5.
Abstract

The title compound resulted from the partial hydrolysis of the reaction product of AICI3, 18-crown-6, and HCl(g) in nitrobenzene. The compound crystallizes in the triclinic space group PI with a = 13.344(2), b = 17.742(3), c = 18.318(3)Å, a = 68.69(1), β = 81.98(1), γ = 68.00(1)°, and D c = 1.45g cm?3 for Z = 3. In the crystal structure the 2+ binuclear aluminum-containing cation is threaded through the crown ether with each aluminum atom coordinated to three crown ether oxygen atoms. The crystal is composed of alternating layers of cations, layers of anions, and bilayers of nitrobenzene molecules.  相似文献   

6.
Concentrated aqueous solutions of magnesium chloride and calcium nitrate, respectively, allow on addition of the potassium salt of tetrathiosquarate, K2C4S4 · H2O, the isolation of the earth alkaline salts MgC4S4 · 6 H2O ( 1 ) and CaC4S4 · 4 H2O ( 2 ) as orange and red crystals. The crystal structure determinations ( 1 : monoclinic, C2/c, a = 17.2280(7), b = 5.9185(2), c = 13.1480(4) Å, β = 104.730(3)°, Z = 4; 2 : monoclinic, P21/m, a = 7.8515(3), b = 12.7705(5), c = 10.6010(4) Å, β = 93.228(2)°, Z = 4) show the presence of C4S42? ions with almost undistorted D4h symmetry having average C–C and C–S bond lengths of 1.451Å and 1.659Å for 1 and 1.451Å and 1.655Å for 2 . The structure of 1 contains discrete, octahedral [Mg(H2O)6]2+ complexes. Several O–H····O and O–H····S bridges with H····O and H····S distances of less than 2.50Å connect cations and anions. The structure of 2 is built of concatenated, edge‐sharing Ca(H2O)6S2 polyhedra. The Ca2+ ions have the coordination number eight, C4S42? act as a chelating ligands towards Ca2+ with Ca–S distances of 3.14Å. The infrared and Raman spectra show bands typical for the molecular building units of the two compounds.  相似文献   

7.
Two new oxovanadium(V) complexes, [2‐MePyH][VvO2(L)] (3) and[2‐EtPyH][VvO2,(L)] (4) (salicylaldehyde 5‐bromo salicyloylhydrazone is abbreviated as H2L; 2‐MePyH is protonated 2‐Mepyridine; 2‐EtPyH presents protonated 2‐Et‐pyridine) were obtained from a reaction of VOSO4 and H2L in acetonitrile‐methanol with small quantity of 2‐Me‐pyridine or 2‐Et‐pyridine, and characterized by X‐ray diffraction and spectroscopic methods. Crystal data: [2‐MePyH][VO2(L)] (3), C20H17N3O5BrV, Mr = 510.2, monoclinic, P21/n, a = 0.7363(1) nm, 6 = 0.9514(1) nm, c = 2.8594(2) nm, β = 95.305(2)°, Z = 4 and V=1.9946(3) nm3, μ(Mo Kα) = 2.539 mm?1; [2‐EtPyH][VO2(L)] (4), C21H19N3 O3BrV, Mr = 524.2, triclinic, P1 , a = 0.8051(1) nm, b = 0.9413(1) nm, c = 1.4648(2) nm, α=99.1900(10)°, α = 99.4530(10)°, γ = 104.6670(10)°, Z = 2 and V= 1.0355(2) nm3, μ(Mo Kα) = 2.448 mm?1, X‐Ray analyses revealed that the crystal structures of 3 and 4 have similar packing modes.  相似文献   

8.
Ruby‐red crystals of Ag2Bi2S3Cl2 were synthesized from AgCl and Bi2S3 by cooling a melt from 770 K to room temperature. X‐ray diffraction on powders and single‐crystals revealed a triclinic crystal structure with special lattice constants (P &1macr; (No. 2), a = 1085.0(2), b = 717.2(1), c = 1137.6(1) pm, α = 89.80(1)?, β = 74.80(1)?, γ = 87.81(1)?). In the structure [BiIIIS3Cl4] polyhedra form 2[BiS3/2Cl4/4] double‐layers by sharing common faces and edges. The silver(I) cations between the layers are coordinated either octahedrally by sulfide ions or tetrahedrally by sulfide and chloride ions. The deviations from the monoclinic space group P 1 21/c 1 are small and induce twinning along [010]. Further pseudosymmetry is based on the stacking of layer packages with the symmetry of the layer group P (2/c) 21/c 2/b.  相似文献   

9.
High‐pressure modifications of the rare earth oxide fluorides REOF (RE = Pr, Nd, Sm – Gd) were successfully synthesized under conditions of 11 GPa and 1200 °C applying the multianvil high‐pressure/high‐temperature technique. Single crystals of HP‐REOF (RE = Nd, Sm, Eu) were obtained making it possible to analyze the products by means of single‐crystal X‐ray diffraction. The compounds HP‐REOF (RE = Nd, Sm, Eu) crystallize in the orthorhombic α‐PbCl2‐type structure (space group Pnma, No. 62, Z = 4) with the parameters a = 632.45(3), b = 381.87(2), c = 699.21(3) pm, V = 0.16887(2) nm3, R1 = 0.0156, and wR2 = 0.0382 for HP‐NdOF, a = 624.38(3), b = 376.87(2), c = 689.53(4) pm, V = 0.16225(2) nm3, R1 = 0.0141, and wR2 = 0.0323 for HP‐SmOF, and a = 620.02(4), b = 374.24(3), c = 686.82(5) pm, V = 0.15937(2) nm3, R1 = 0.0177, and wR2 = 0.0288 for HP‐EuOF. Calculations of the bond valence sums clearly showed that the oxygen atoms occupy the tetrahedrally coordinated position, whereas the fluorine atoms are fivefold coordinated in form of distorted square‐pyramids. The crystal structures and properties of HP‐REOF (RE = Nd, Sm, Eu) are discussed and compared to the isostructural phases and the normal‐pressure modifications of REOF (RE = Nd, Sm, Eu). Furthermore, results of investigations by EDX and Raman measurements including quantum mechanical calculations are presented.  相似文献   

10.
薛思佳  卞王东  柴安  吁松瑞 《中国化学》2008,26(8):1501-1505
本文首次合成标题化合物N-(4-甲基苯甲酰氨基)-N’-[5-(2-三氟甲基苯基)-2-呋喃甲酰硫脲。化合物(C21H16F3N3O3S, Mr = 447.43)单晶经测定为单斜晶体,空间群为P -1。在晶体中,存在一些分子内和分子间的相互作用,分子间还有C—H···π 的相互作用,这可能导致晶体更稳定的原因。目标产物的结构经IR, H NMR和元素分析测定确证。初步生物活性测试表明,部分化合物对棉花枯萎病、黄瓜灰霉病、苹果轮纹病和棉花炭疽病有较好的选择性杀菌活性;部分目标化合物有较好的除草活性。  相似文献   

11.
The rare earth‐rich compounds RE23Rh7Mg4 (RE = La, Ce, Pr, Nd, Sm, Gd) were prepared by induction‐melting the elements in sealed tantalum tubes. The new compounds were characterized by X‐ray powder diffraction. They crystallize with the hexagonal Pr23Ir7Mg4 type structure, space group P63mc. The structures of La23Rh7Mg4 (a = 1019.1(1), c = 2303.7(4) pm, wR2 = 0.0827, 1979 F2 values, 69 variables), Nd23Rh7Mg4 (a = 995.4(2), c = 2242.3(5) pm, wR2 = 0.0592, 2555 F2 values, 74 variables) and Gd23Rh6.86(5)Mg4 (a = 980.5(2), c = 2205.9(5) pm, wR2 = 0.0390, 2083 F2 values, 71 variables) were refined from single crystal X‐ray diffractometer data. The three crystallographically different rhodium atoms have trigonal prismatic rare earth coordination with short RE–Rh distances (283–300 pm in Nd23Rh7Mg4). The prisms are condensed via common edges, leading to a rigid three‐dimensional network in which isolated Mg4 tetrahedra (312–317 pm Mg–Mg in Nd23Rh7Mg4) are embedded. Temperature dependent magnetic susceptibility data of Ce23Rh7Mg4 indicate Curie‐Weiss behavior with an experimental magnetic moment of 2.52(1) μB/Ce atom, indicative for stable trivalent cerium. Antiferromagnetic ordering is evident at 2.9 K.  相似文献   

12.
Two uranyl sulfate hydrates, (H3O)2[(UO2)2(SO4)3(H2O)] · 7H2O (NDUS) and (H3O)2[(UO2)2(SO4)3(H2O)] · 4H2O (NDUS1), and one uranyl selenate‐selenite [C5H6N][(UO2)(SeO4)(HSeO3)] (NDUSe), were obtained and their crystal structures solved. NDUS and NDUSe result from reactions in highly acidic media in the presence of L ‐cystine at 373 K. NDUS crystallized in a closed vial at 278 K after 5 days and NDUSe in an open beaker at 278 K after 2 weeks. NDUS1 was synthesized from aqueous solution at room temperature over the course of a month. NDUS, NDUS1, and NDUSe crystallize in the monoclinic space group P21/n, a = 15.0249(4) Å,b = 9.9320(2) Å, c = 15.6518(4) Å, β = 112.778(1)°, V = 2153.52(9) Å3,Z = 4, the tetragonal space group P43212, a = 10.6111(2) Å,c = 31.644(1) Å, V = 3563.0(2) Å3, Z = 8, and in the monoclinic space group P21/n, a = 8.993(3) Å, b = 13.399(5) Å, c = 10.640(4) Å,β = 108.230(4)°, V = 1217.7(8) Å3, Z = 4, respectively.The structural units of NDUS and NDUS1 are two‐dimensional uranyl sulfate sheets with a U/S ratio of 2/3. The structural unit of NDUSe is a two‐dimensional uranyl selenate‐selenite sheets with a U/Se ratio of 1/2. In‐situ reaction of the L ‐cystine ligands gives two distinct products for the different acids used here. Where sulfuric acid is used, only H3O+ cations are located in the interlayer space, where they balance the charge of the sheets, whereas where selenic acid is used, interlayer C5H6N+ cations result from the cyclization of the carboxyl groups of L ‐cystine, balancing the charge of the sheets.  相似文献   

13.
IntroductionDuringthepastdecades ,thedevelopmentoftheco ordinationchemistryofmolybdenum(VI)focusedonmet al oxygenclusterscharacterizedbyfascinatingstructural,electrochemical,catalytic ,magnetic ,medicinal,andphotophysicalproperties ,1whichareoffundamentaland…  相似文献   

14.
The title salt, C6H6NO2+·ClO4·C6H5NO2, was crystallized from an aqueous solution of equimolar quantities of perchloric acid and pyridine‐2‐carboxylic acid. Differential scanning calorimetry (DSC) measurements show that the compound undergoes a reversible phase transition at about 261.7 K, with a wide heat hysteresis of 21.9 K. The lower‐temperature polymorph (denoted LT; T = 223 K) crystallizes in the space group C2/c, while the higher‐temperature polymorph (denoted RT; T = 296 K) crystallizes in the space group P2/c. The relationship between these two phases can be described as: 2aRT = aLT; 2bRT = bLT; cRT = cLT. The crystal structure contains an infinite zigzag hydrogen‐bonded chain network of 2‐carboxypyridinium cations. The most distinct difference between the higher (RT) and lower (LT) temperature phases is the change in dihedral angle between the planes of the carboxylic acid group and the pyridinium ring, which leads to the formation of different ten‐membered hydrogen‐bonded rings. In the RT phase, both the perchlorate anions and the hydrogen‐bonded H atom within the carboxylic acid group are disordered. The disordered H atom is located on a twofold rotation axis. In the LT phase, the asymmetric unit is composed of two 2‐carboxypyridinium cations, half an ordered perchlorate anion with ideal tetrahedral geometry and a disordered perchlorate anion. The phase transition is attributable to the order–disorder transition of half of the perchlorate anions.  相似文献   

15.
Novel structures of luminescent materials, which are used as light sources for next‐generation illumination, are continuously being improved for use in white‐light‐emitting diodes. Activator‐doped known structures are reported as habitual down‐conversion phosphors in solid‐state lightings and displays. Consequently, the intrinsic qualities of the existent compounds produce deficiencies that limit their applications. Herein we report a spiral‐network single‐crystal orthophosphate (LiSrPO4) prepared in a platinum crucible with LiCl flux through crystal‐growth reactions of SrCl2 and Li3PO4 in air. It crystallizes in a hexagonal system with a=5.0040(2) and c=24.6320(16) Å, V=534.15(5) Å3, and Z=6 in the space group P65. The unit cell is comprised of LiO4 and PO4 tetrahedrons that form a three‐dimensional LiPO42? anionic framework with a helical channel structure along the c axis in which the Sr2+ cation is accommodated. The optical band gap of this composition is about 3.65 eV, as determined by using UV/Vis absorption and diffuse reflection spectra. We used the crystal‐growth method to synthesize blue‐ and red‐emitting crystals that exhibited pure color, low reabsorption, a large Stokes shift, and efficient conversion of ultraviolet excitation light into visible light. Emphasis was placed on the development of gratifying structure‐related properties of rare‐earth luminescent materials and their applications.  相似文献   

16.
The title compounds, bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ2N1:P}disilver bis(perchlorate) acetonitrile monosolvate, [Ag2(C18H17N2P)2](ClO4)2·CH3CN, (1), and bis{μ‐N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine‐κ2N1:P}bis[(nitrato‐κ2O,O)silver], [Ag2(C18H17N2P)2(NO3)2], (2), each contain disilver macrocyclic [Ag2(C18H17N2P)2]2+ cations lying about inversion centres. The cations are constructed by two N‐[(diphenylphosphanyl)methyl]pyridin‐4‐amine (DPP) ligands linking two Ag+ cations in a head‐to‐tail fashion. In (1), the unique Ag+ cation has a near‐linear coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands. Two ClO4 anions doubly bridge two metallomacrocycles through Ag...O and N—H...O weak interactions to form a chain extending in the c direction. The half‐occupancy acetonitrile molecule lies with its methyl C atom on a twofold axis and makes a weak N...Ag contact. In (2), there are two independent [Ag(C18H17N2P)]+ cations. The nitrate anions weakly chelate to each Ag+ cation, leading to each Ag+ cation having a distorted tetrahedral coordination geometry consisting of one pyridine N atom and one P atom from two different DPP ligands, and two chelating nitrate O atoms. Each dinuclear [Ag2(C18H17N2P)2(NO3)2] molecule acts as a four‐node to bridge four adjacent equivalent molecules through N—H...O interactions, forming a two‐dimensional sheet parallel to the bc plane. Each sheet contains dinuclear molecules involving just Ag1 or Ag2 and these two types of sheet are stacked in an alternating fashion. The sheets containing Ag1 all lie near x = , , etc, while those containing Ag2 all lie near x = 0, 1, 2 etc. Thus, the two independent sheets are arranged in an alternating sequence at x = 0, , 1, etc. These two different supramolecular structures result from the different geometric conformations of the templating anions which direct the self‐assembly of the cations and anions.  相似文献   

17.
The crystalline complex dipotassium 1,3-diammonio-2-propanone tetrachloroplatinate trihydrate, formulated as K2[(NH3CH2C)2O][PtCl4]2 · 3H2O, has been prepared while synthesizing complexes analogous tocis-dichlorodiamine Pt(II). Its structure is orthorhombic, space groupPnma,M r = 896.1,F(000) = 1640,a = 8.428(4),b = 20.360(10),c = 12.141(7)A,V = 2083.3Å3,Z = 4,D x = 2.860 g cm–3, (MoK x) = 196 cm–1, finalR = 0.083 for 1379 unique reflections. The structure consists of a very extended hydrogen bonded network which involves half of the PtCl4 2– ions, the organic molecules and the water molecules of hydration, leaving large oval channels which accommodate potassium cations and tetrachloroplatinate anions. Within the channel the potassium and tetrachloroplatinate ions pack in columns extending along the a axis. The dense packing is rather reminiscent of that found in the neat salt where each potassium ion is surrounded by six chlorine atoms which describe a polyhedron of a distorted trigonal prism with K+ —C1 distances ranging between 3.163–3.187 Å. There is some indirect evidence for the formation of 1,3-diammonio-2-propanone dications which counterbalance the charges of half of the PtCl4 2– ions by protonation of each of the amino nitrogens. The carbonyl oxygens, however, are involved only in a very weak O-C-O interactions along thea axis.  相似文献   

18.
The monomeric cobalt-phosphite-thiolato complex [ Co (mpt)2 {P (OCH3 )3 }2 ] BF4 (Hmpt = 2-mercaptothiazoline) has been prepared and characterized by X-ray crystallography. The complex crystallizes in the monoclinic space group C2/c with a= 0.8078(5), b=2.6020(18), c=1.2191(7) nm, β= 99.38 (1)°, V= 2.528(3) nm3, and Z = 4. The structure comprises discrete cations [Co(mpt)2{P(OCH3)3}2.] and anions BF4- , in which the cobalt (Ⅲ) atom is coordinated to two chelate mpt- and two as-oriented monodentate P(OCH3)3 ligands in a highly distorted octahedral geometry. The most distorted angles are S(2)-Co(1)-S(2a) of 162.23(10)° and N(1)-Co(1)-S(2) of 71. 47 (13)°, the latter is caused by the geometric constraint of the bidentate ligand mpt- . Cyclic voltammetry has been used to study the electrochemical behavior of the title complex on the R electrode in MeCN solution with 0.1 mol·L-1 of Bun4NBF4 as electrolyte. The results indicate that the title complex is unstable in MeCN.  相似文献   

19.
Red‐orange, transparent single crystals of EuCN2 (Pnma (62), a = 1232.41(9), b = 395.26(3) and c = 539.43(4) pm, Z = 4) are obtained by the reaction of EuN, C and NaN3 in arc‐welded Ta ampoules at 1300 K. The first ternary rare earth metal cyanamide is isotypic to α‐SrCN2 and shows the characteristic frequencies for the CN22— unit in the optical spectra (νs = 1244; νas = 1969 and 2087; δ = 655 / 666 cm—1).  相似文献   

20.
[(Cp4i Rh)2(μ‐Cl)3] [Rh(CO)2Cl2] (Cp4i = tetraisopropyl‐cyclopenta‐dienyl) has been prepared and its crystal is in the space group of Pbar with a= 0.9417 (8), b = 1.4806 (3), c = 1.5062 (2) nm, a = 92.980(10), β = 97.42(3), γ = 93.98 (3)°, V = 2.0735(18) nm3 and Z = 2. The crystal structure consists of a cation of [(η5‐Cp4i) Rh (III)(μ‐Cl)3 Rh (III) (η5‐Cp4i)]+ and an anion of [Rh (I) (CO)2 Cl2]. The two bulky tetraisopropylcyclopentadienyl ligands are in the ecliptic conformation with angle of 10.19° between two cyclopentadienyl ring planes.  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