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1.
Two coordination polymers {[Cd(phen)](C6H8O4)3/3} ( 1 ) and {[Cd(phen)](C7H10O4)3/3} · 2H2O ( 2 ) were structurally characterized by single crystal X‐ray diffraction methods. In 1 (C2/c (no. 15), a = 16.169(2)Å, b = 15.485(2)Å, c = 14.044(2)Å, β = 112.701(8)°, U = 3243.9(7)Å3, Z = 8), the Cd atoms are coordinated by two N atoms of one phen ligand and five O atoms of three adipato ligands to form mono‐capped trigonal prisms with d(Cd‐O) = 2.271‐2.583Å and d(Cd‐N) = 2.309, 2.390Å. The [Cd(phen)] moieties are bridged by adipato ligands to generate {[Cd(phen)](C6H8O4)3/3} chains, which, via interchain π—π stacking interactions, are assembled into layers. Complex 2 (P1¯(no. 2), a = 9.986(1)Å, b = 10.230(3)Å, c = 11.243(1)Å, α = 66.06(1)°, β = 87.20(1)°, γ = 66.71(1)°, U = 955.7(2)Å3, Z = 2) consists of {[Cd(phen)](C7H10O4)3/3} chains and hydrogen bonded H2O molecules. The Cd atoms are pentagonal bipyramidally coordinated by two N atoms of one phen ligand and five O atoms of three pimelato ligands with d(Cd‐O) = 2.213—2.721Å and d(Cd‐N) = 2.329, 2.372Å. Through interchain π—π stacking interactions, the {[Cd(phen)](C7H10O4)3/3} chains resulting from [Cd(phen)] moieties bridged by pimelato ligands are assembled in to layers, between which the hydrogen bonded H2O molecules are sandwiched.  相似文献   

2.
The organically templated pentaborate [C10N2H9][B5O6(OH)4] · H3BO3 · H2O ( 1a ) was synthesized by boric acid and 4, 4′‐bipyridine in aqueous solution and characterized by single‐crystal X‐ray diffraction, elemental analysis, FTIR spectroscopy, thermogravimetric analysis, powder X‐ray diffraction, and photoluminescence spectroscopy. The compound crystallizes in the triclinic system with space group P$\bar{1}$ (a = 9.196(3) Å, b = 9.822(3) Å, c = 12.113(3) Å, α = 66.243(3)°, β = 76.998(3)°, γ = 75.067(3)°, V = 958.4(5) Å3, and Z = 2). The polyanions form a novel 3D supramolecular network with three kinds of channels by extensive hydrogen bonds. The title compound shows a UV photoluminescence with an emission maximum at 372 nm upon excitation at 248 nm, and the photoluminescence can be modified from UV to blue by means of a simple heat‐treatment process. The pentaborate could be a promising blue component for possible application in the white LED.  相似文献   

3.
Single crystals of Sr[B(C6H5O7)2](H2O)4 · 3H2O, a new borate‐citrate material, were grown with sizes up to 8 × 6 × 2 mm by slow evaporation of water at room temperature. The structure of Sr[B(C6H5O7)2](H2O)4 · 3H2O was determined by single‐crystal X‐ray diffraction. It crystallizes in the monoclinic space group P21/c, with a = 11.363(3) Å, b = 18.829(4) Å, c = 11.976(3) Å, β = 110.736(3)°, and Z = 4. The SrO8 dodecahedra, BO4 tetrahedra and citrate groups are linked together to form chains. The compound was characterized by IR and UV/Vis/NIR transmittance spectroscopy as well as thermal analysis.  相似文献   

4.
[Cd(H2O)3(C5H6O4)]·2H2O ( 1 ) and Cd(H2O)2(C6H8O4) ( 2 ) were prepared from reactions of fresh CdCO3 precipitate with aqueous solutions of glutaric acid and adipic acid, respectively, while Cd(H2O)2(C8H12O4) ( 3 ) crystallized in a filtrate obtained from the hydrothermal reaction of CdCl2·2.5H2O, suberic acid and H2O. Compound 1 consists of hydrogen bonded water molecules and linear {[Cd(H2O)3](C5H6O4)2/2} chains, which result from the pentagonal bipyramidally coordinated Cd atoms bridged by bis‐chelating glutarato ligands. In 2 and 3 , the six‐coordinate Cd atoms are bridged by bis‐chelating adipato and suberato ligands into zigzag chains according to {[Cd(H2O)3](C5H6O4)2/2} and {[Cd(H2O)2](C8H12O4)2/2}, respectively. The hydrogen bonds between water and the carboxylate oxygen atoms are responsible for the supramolecular assemblies of the zigzag chains into 3D networks. Crystallographic data: ( 1 ) P1¯ (no. 2), a = 8.012(1), b = 8.160(1), c = 8.939(1) Å, α = 82.29(1)°, β = 76.69(1)°, γ = 81.68(1)°, U = 559.6(1) Å3, Z = 2; ( 2 ) C2/c (no. 15), a = 16.495(1), b = 5.578(1), c = 11.073(1) Å, β = 95.48(1)°, U = 1014.2(1) Å3, Z = 4; ( 3 ) P2/c (no. 13), a = 9.407(2), b = 5.491(1), c = 11.317(2) Å, β = 95.93(3)°, U = 581.4(2) Å3, Z = 2.  相似文献   

5.
Novel Oxonium Halogenochalcogenates Stabilized by Crown Ethers: [H3O(Dibromo‐benzo‐18‐crown‐6)]2[Se3Br10] and [H5O2(Bis‐dibromo‐dibenzo‐24‐crown‐8]2[Se3Br8] Two novel complex oxonium bromoselenates(II,IV) and –(II) are reported containing [H3O]+ and [H5O2]+ cations coordinated by crown ether ligands. [H3O(dibromo‐benzo‐18‐crown‐6)]2[Se3Br10] ( 1 ) and [H5O2(bis‐dibromo‐dibenzo‐24‐crown‐8]2[Se3Br8] ( 2 ) were prepared as dark red crystals from dichloromethane or acetonitrile solutions of selenium tetrabromide, the corresponding unsubstituted crown ethers, and aqueous hydrogen bromide. The products were characterized by their crystal structures and by vibrational spectra. 1 is triclinic, space group (Nr. 2) with a = 8.609(2) Å, b = 13.391(3) Å, c = 13.928(3) Å, α = 64.60(2)°, β = 76.18(2)°, γ = 87.78(2)°, V = 1404.7(5) Å3, Z = 1. 2 is also triclinic, space group with a = 10.499(2) Å, b = 13.033(3) Å, c = 14.756(3) Å, α = 113.77(3)°, β = 98.17(3)°, γ = 93.55(3)°. V = 1813.2(7) Å3, Z = 1. In the reaction mixture complex redox reactions take place, resulting in (partial) reduction of selenium and bromination of the crown ether molecules. In 1 the centrosymmetric trinuclear [Se3Br10]2? consists of a central SeIVBr6 octahedron sharing trans edges with two square planar SeIIBr4 groups. The novel [Se3Br8]2? in 2 is composed of three planar trans‐edge sharing SeIIBr4 squares in a linear arrangement. The internal structure of the oxonium‐crown ether complexes is largely determined by the steric restrictions imposed by the aromatic rings in the crown ether molecules, as compared to complexes with more flexible unsubstituted crown ether ligands.  相似文献   

6.
Reactions of 1,10‐phenanthroline monohydrate, Na2C4H4O4 · 6 H2O and MnSO4 · H2O in CH3OH/H2O yielded a mixture of [Mn2(H2O)4(phen)2(C4H4O4)2] · 2 H2O ( 1 ) and [Mn(phen)2(H2O)2][Mn(phen)2(C4H4O4)](C4H4O4) · 7 H2O ( 2 ). The crystal structure of 1 (P1 (no. 2), a = 8.257(1) Å, b = 8.395(1) Å, c = 12.879(2) Å, α = 95.33(1)°, β = 104.56(1)°, γ = 106.76(1)°, V = 814.1(2) Å3, Z = 1) consists of the dinuclear [Mn2(H2O)4(phen)2(C4H4O4)2] molecules and hydrogen bonded H2O molecules. The centrosymmetric dinuclear molecules, in which the Mn atoms are octahedrally coordinated by two N atoms of one phen ligand and four O atoms from two H2O molecules and two bis‐monodentate succinato ligands, are assembled via π‐π stacking interactions into 2 D supramolecular layers parallel to (101) (d(Mn–O) = 2.123–2.265 Å, d(Mn–N) = 2.307 Å). The crystal structure of 2 (P1 (no. 2), a = 14.289(2) Å, b = 15.182(2) Å, c = 15.913(2) Å, α = 67.108(7)°, β = 87.27(1)°, γ = 68.216(8)°, V = 2934.2(7) Å3, Z = 2) is composed of the [Mn(phen)2(H2O)2]2+ cations, [Mn(phen)2(C4H4O4)] complex molecules, (C4H4O4)2– anions, and H2O molecules. The (C4H4O4)2– anions and H2O molecules form 3 D hydrogen bonded network and the cations and complex molecules in the tunnels along [001] and [011], respectively, are assembled via the π‐π stacking interactions into 1 D supramolecular chains. The Mn atoms are octahedrally coordinated by four N atoms of two bidentate chelating phen ligands and two water O atoms or two carboxyl O atoms (d(Mn–O) = 2.088–2.129 Å, d(Mn–N) = 2.277–2.355 Å). Interestingly, the succinato ligands in the complex molecules assume gauche conformation bidentately to chelate the Mn atoms into seven‐membered rings.  相似文献   

7.
Syntheses of the sky blue complex compounds [Ni(H2O)3(phen)(C5H6O4)] · H2O ( 1 ) and [Ni(H2O)2(phen)(C5H6O4)] ( 2 ) were carried out by the reactions of 1,10‐phenanthroline monohydrate, glutaric acid, NiSO4 · 6 H2O and Na2CO3 in CH3OH/H2O at pH = 6.9 and 7.5, respectively. The crystal structure of 1 (P 1 (no. 2), a = 14.289 Å, b = 15.182 Å, c = 15.913 Å, α = 67.108°, β = 87.27°, γ = 68.216°, V = 2934.2 Å3, Z = 2) consists of hydrogen bonded [Ni(H2O)3‐ (phen)(C5H6O4)]2 dimers and H2O molecules. The Ni atoms are octahedrally coordinated by two N atoms of one phen ligand, three water O atoms and one carboxyl O atom from one monodentate glutarato ligand (d(Ni–N) = 2.086, 2.090 Å; d(Ni–O) = 2.064–2.079 Å). Through the π‐π stacking interactions and intermolecular hydrogen bonds, the dimers are assembled to form 2 D layers parallel to (0 1 1). The crystal structure of 2 (P21/n (no. 14), a = 7.574 Å, b = 11.938 Å, c = 18.817 Å, β = 98.48°, V = 1682.8 Å3, Z = 4) contains [Ni(H2O)2(phen)(C5H6O4)2/2] supramolecular chains extending along [010]. The Ni atoms are octahedrally coordinated by two N atoms of one phen ligand, two water O atoms and two carboxyl O atoms from different bis‐monodentate glutarato ligands with d(Ni–N) = 2.082, 2.105 Å and d(Ni–O) = 2.059–2.087 Å. The supramolecular chains are assembled into a 3 D network by π‐π stacking interactions and interchain hydrogen bonds. A TG/DTA of 2 shows two endothermic effects at 132 °C and 390 °C corresponding to the complete dehydration and the lost of phen.  相似文献   

8.
Crystal Structure of Sodium Dihydrogencyamelurate Tetrahydrate Na[H2(C6N7)O3] · 4 H2O Sodium dihydrogencyamelurate‐tetrahydrate Na[H2(C6N7)O3]·4 H2O was obtained by neutralisation of an aqueous solution, previously prepared by hydrolysis of the polymer melon with sodium hydroxide. The crystal structure was solved by single‐crystal X‐ray diffraction ( a = 6.6345(13), b = 8.7107(17), c = 11.632(2) Å, α = 68.96(3), β = 87.57(3), γ = 68.24(3)°, V = 579.5(2) Å3, Z = 2, R1 = 0.0535, 2095 observed reflections, 230 parameters). Both hydrogen atoms of the dihydrogencyamelurate anion are directly bound to nitrogen atoms of the cyameluric nucleus, thus proving the preference of the keto‐tautomere in salts of cyameluric acid in the solid‐state. The compound forms a layer‐like structure with an extensive hydrogen bonding network.  相似文献   

9.
Crystal Structure of SrZn(OH)4 · H2O Colorless crystals of SrZn(OH)4 · H2O are obtained by electrochemical oxidation of Zn in a zinc/iron pair in an aqueous ammonia solution saturated with strontium hydroxide. The X-ray crystal structure determination was now successful including all hydrogen positions: P1 , Z = 2, a = 6.244(1) Å, b = 6.3000(8) Å, c = 7.701(1) Å, α = 90.59(1)°, β = 112.56(2)°, γ = 108.66(2)°, N(F ≥ 3σF) = 1967, N(Var.) = 84, R/Rw = 0.020/0.024. In SrZn(OH)4 · H2O Zn2+ is tetrahedrally coordinated by four OH? -ions while Sr2+ has 6 OH? and one H2O as neighbours. The polyhedra around Sr2+ are connected to chains which are linked three-dimensionally by isolated tetrahedra [Zn(OH)4]. Hydrogen bonds between H2O as donor and OH? are characterized by raman spectroscopy.  相似文献   

10.
A new protonated borophosphate (H3O)Mg(H2O)2[BP2O8]·H2O ( 1 ) was synthesized under mild hydrothermal conditions and characterized by single‐crystal X‐ray diffraction, FTIR spectroscopy and TG‐DTA. The compound crystallizes in the hexagonal system, space group P6(1)22 (No 178), a = 9.4462(7) Å, c = 15.759(2) Å, V = 1217.8(2) Å3, and Z = 6. There exist infinite helical $^1_\infty$ {[BP2O8]3–} ribbons built up from corner‐sharing PO4 and BO4 tetrahedra, which are connected by MgO4(H2O)2 leading to an infinite three‐dimensional open‐framework. The H3O+ ions are located at the free thread of the helical ribbons, whereas crystallized water occupy the channels of the helical ribbons. The dehydration of the compound occurs at a higher temperature which is presumably due to the anisotropic hydrogen bonds in the crystal structure. The luminescent properties of the compound were studied.  相似文献   

11.
The single crystals of (C2H7N4O)2[UO2(C2O4)2(H2O)] were studied by X-ray diffraction. The crystals are monoclinic, space group Pn, Z = 2, unit cell parameters: a = 9.4123(2) Å, b = 8.4591(2) Å, c = 11.8740(3) Å, β = 105.500(10)°, V = 911.02(4) Å3. The main structural units of the crystals of I are islet complex groups [UO2(C2O4)2(H2O)]2? corresponding to the crystal chemical group AB 2 01 M1 (A = UO UO 2 2+ , B01 = C2O 4 2? , M = H2O) of uranyl complexes. Uranium-containing mononuclear complexes are connected into a three-dimensional framework through the electrostatic interactions and hydrogen bonding system involving carbamyolguanidinium ions.  相似文献   

12.
Crystal Structure of CaZn2(OH)6 · 2 H2O The electrochemical oxidation of zinc in a zinc/iron-pair leads in an aqueous NH3 solution of calciumhydroxide at room temperature to colourless crystals of CaZn2(OH)6 · 2 H2O. The X-ray structure determination was now successful including all hydrogen positions. P21/c, Z = 2, a = 6.372(1) Å, b = 10.940(2) Å, c = 5.749(2) Å, β = 101.94(2)° N(F ≥ 3σF) = 809, N(Var.) = 69, R/RW = 0.011/0.012 The compound CaZn2(OH)6 · 2H2O contains Zn2+ in tetrahedral coordination by OH? and Ca2+ in octahedral coordination by four OH? and two H2O. The tetrahedra around Zn2+ form corner sharing chains, three-dimensionally linked by isolated polyhedra around Ca2+. Weak hydrogen bridge bonds result between H2O as donor and OH?.  相似文献   

13.
Dark blue plate‐like crystals of [Cu2(phen)2 · (H2O)2(OH)2](HCO3)2 · 6 H2O were obtained from a CH3OH–H2O solution containing CuCl2, 1,10‐phenanthroline (phen), sebacic acid and Na2CO3. The crystal structure (triclinic, P 1 (no. 2), a = 8.118(1), b = 9.624(1), c = 10.536(1) Å, α = 81.35(1)°, β = 88.51(1)°, γ = 75.77(1)°, Z = 1, R = 0.0332, wR2 = 0.0981 for 4163 observed reflections (F ≥ 2σ(F ) out of 4595 unique reflections) consists of divalent [Cu2(phen)2(H2O)2(OH)2]2+ complex cations, anionic (HCO3)22– dimers and H2O molecules. The divalent complex cations (d(Cu…Cu) = 2.905(1) Å) are centered at inversion centers. The Cu atoms are fivefold square‐pyramidally coordinated by two nitrogen and three oxygen atoms from one bidentate chelating phen ligand, two bridging hydroxide groups and one axial water molecule (d(Cu–N)phen = 2.021(2), 2.024(2) Å; d(Cu–O)OH = 1.941(1), 1.949(1) Å; d(Cu–O)H2O = 2.254(2) Å). The divalent complex cations are stacked to form 2 D layers parallel (001) with 1 D π‐π stacking interactions along [100] via the terminal phen rings. The dimeric (HCO3)22– anions and the hydrogen bonded H2O molecules are sandwiched between the 2 D layers.  相似文献   

14.
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   

15.
Crystals of anionic Na[CuCl2(HOCH2C≡CCH2OH)]·2H2O π‐complex have been synthesized by interaction of 2‐butyne‐1,4‐diol with CuCl in a concentrated aqueous NaCl solution and characterized by X‐ray diffraction at 100 K. The crystals are triclinic: space group , a = 7.142(3), b = 7.703(3), c = 10.425(4) Å, α = 105.60(3), β = 99.49(3), γ = 110.43(3)°, V = 495.9(4) Å3, Z = 2, R = 0.0203 for 3496 reflections. The structure is built of discrete [CuCl2(HOCH2C≡CCH2OH)]? anionic stacks and polymeric cations among the stacks. The CuI atom adopts trigonal planar coordination of two Cl? anions and the C≡C bond of 2‐butyne‐1,4‐diol, Cu–(C≡C) distance is equal to 1.903(3) Å. Na+ cations environment is octahedral and consists of O and Cl atoms. The crystal packing is governed by strong hydrogen bonds of O–H···Cl and O–H···O types.  相似文献   

16.
Three adipato bridged mixed ligand catena complexes {[M(phen)(H2O)]‐(C6H8O4)2/2} with M = NiII ( 1 ), CuII ( 2 ), ZnII ( 3 ) were synthesized. Structure determination based on X‐ray diffraction shows that they crystallize isostructurally in the monoclinic space group C2/c (no. 15) with cell dimensions of: 1 a = 22.451(4)Å, b = 9.041(1)Å, c = 17.440(2)Å, β = 103.41(1)°, U = 3443.4(9)Å3, Z = 8; 2 a = 22.479(2)Å, b = 9.067(1)Å, c = 17.494(3)Å, β = 103.67(1)°, U = 3464.6(8)Å3, Z = 8; 3 a = 22.635(3)Å, b = 9.052(1)Å, c = 17.571(3)Å, β = 103.24(1)°, U = 3504.5(9)Å3, Z = 8. The crystal structure consists of 1D {[M(phen)(H2O)]‐(C6H8O4)2/2} zigzag chains, in which the metal atoms are all octahedrally coordinated by two N atoms of one phen ligands and four O atoms of one H2O molecule and two adipato ligands. The zigzag chains are held together by interchain π‐π stacking interactions and interchain hydrogen bonds.  相似文献   

17.
The reaction of Gd(ClO4)3·6H2O with 5‐(1H‐tetrazol‐5‐yl)isophthalic acid affords a 3D framework gadolinium coordination polymer, [Gd(C9H3N4O4)(H2O)3·2H2O]n ( 1 ). Its crystal structure belongs to a triclinic system, space group , with a = 7.909(2) Å; b = 8.448(2) Å; c = 10.994(2) Å; α = 102.65(3)°; β = 124.32(2)°; γ = 96.28(3)°; V = 704.5(2) Å3; Z = 2; R1 = 0.0245 for 3225 reflections with I >2σ(I), wR2 = 0.0556. Fluorescent analyses show that compound 1 exhibits purple fluorescence in the solid state at room temperature.  相似文献   

18.
The blue copper complex compounds [Cu(phen)2(C6H8O4)] · 4.5 H2O ( 1 ) and [(Cu2(phen)2Cl2)(C6H8O4)] · 4 H2O ( 2 ) were synthesized from CuCl2, 1,10‐phenanthroline (phen) and adipic acid in CH3OH/H2O solutions. [Cu(phen)2‐ (C6H8O4)] complexes and hydrogen bonded H2O molecules form the crystal structure of ( 1 ) (P1 (no. 2), a = 10.086(2) Å, b = 11.470(2) Å, c = 16.523(3) Å, α = 99.80(1)°, β = 115.13(1)°, γ = 115.13(1)°, V = 1617.5(5) Å3, Z = 2). The Cu atoms are square‐pyramidally coordinated by four N atoms of the phen ligands and one O atom of the adipate anion (d(Cu–O) = 1.989 Å, d(Cu–N) = 2.032–2.040 Å, axial d(Cu–N) = 2.235 Å). π‐π stacking interactions between phen ligands are responsible for the formation of supramolecular assemblies of [Cu(phen)2(C6H8O4)] complex molecules into 1 D chains along [111]. The crystal structure of ( 2 ) shows polymeric [(Cu2(phen)2Cl2)(C6H8O4)2/2] chains (P1 (no. 2), a = 7.013(1) Å, b = 10.376(1) Å, c = 11.372(3) Å, α = 73.64(1)°, β = 78.15(2)°, γ = 81.44(1)°, V = 773.5(2) Å3, Z = 1). The Cu atoms are fivefold coordinated by two Cl atoms, two N atoms of phen ligands and one O atom of the adipate anion, forming [CuCl2N2O] square pyramids with an axial Cl atom (d(Cu–O) = 1.958 Å, d(Cu–N) = 2.017–2.033 Å, d(Cu–Cl) = 2.281 Å; axial d(Cu–Cl) = 2.724 Å). Two square pyramids are condensed via the common Cl–Cl edge to centrosymmetric [Cu2Cl2N4O2] dimers, which are connected via the adipate anions to form the [(Cu2(phen)2Cl2)(C6H8O4)2/2] chains. The supramolecular 3 D network results from π‐π stacking interactions between the chains. H2O molecules are located in tunnels.  相似文献   

19.
The crystal structure of EMIm diaquobis(μ‐oxalato)chromate(III) (1‐ethyl‐3‐methylimidazolium chromium(III) dioxalate dihydrate) was determined from X‐ray single crystal diffraction studies. A pale violet crystal of good optical quality was used for the structure determination at –100(2) and 25(2) °C. The basic crystallographic data for the low temperature structure are as follows: triclinic symmetry, space group P$\bar{1}$ , a = 7.6202(8) Å, b = 9.7668(9) Å, c = 10.7171(11) Å, α = 109.257(9)°, β = 90.494(8)°, γ = 105.685(8)°, V = 720.75(1) Å3. The crystal structure was solved by direct methods and refined (using anisotropic displacement parameters for all non‐hydrogen atoms) to a final residual of R1 = 0.039 for 2062 independent observed reflections [I > 2σ(I)]. The compound is built up from alternating layers parallel to (010) containing (EMIm)+ cations or Cr(C2O4)2(H2O)2 anions, respectively. The two crystallographically independent Cr(C2O4)2(H2O)2 octahedra reside on centers of symmetry (Wyckoff sites 1a and 1f). The corners of the octahedra consist of four oxygen atoms from two oxalate groups and two additional water molecules. EMIm+ cations provide linkage between different octahedral layers by hydrogen bridging. The water molecules in turn form hydrogen bonds with adjacent octahedra within the same layer. According to DTA/TG experiments the present compound shows several thermal processes in the range between room temperature and 1000 °C. However, pyrolysis is reproducibly yielding pure inorganic composites, qualifying this novel organic‐inorganic hybrid salt also as a stable precursor for nanoscalar ceramic materials. The final product consists of a distinct mixture of Cr2O3 and Cr3C2 in the molar ratio of 1:1. Concomittant oxide and carbide formation is an unprecedented disintegration pathway of the thermal treatment of oxalatochromates without reducing atmosphere.  相似文献   

20.
In the system 2,2′‐bipyridine/MnIII/HF/H3PO4/H2O two compounds with chain structures could be prepared and characterised by X‐ray structure analyses. 2,2′‐bipyMn(H2PO4)F2·H2O ( 1 ): monoclinic, twinned, space group P21/c, Z = 4, a = 6.7883(4), b = 10.9147(5), c = 17.8102(8) Å, β = 100.142(4)°, R = 0.0328. 2,2′‐bipyMn(H2PO4)2F ( 2 ): triclinic, space group P , Z = 2, a = 6.675(1), b = 10.715(1), c = 11.013(1) Å, α = 107.595(9)°, β = 90.994(9)°, γ = 95.784(8)°, R = 0.0252. Both compounds show chain structures with trans‐bridging dihydrogenphosphate ligands and bipy and two fluorine ligands for ( 1 ), or bipy, fluorine and an additional dihydrogenphosphate, respectively, for ( 2 ) in equatorial positions. Due to the pseudo‐Jahn–Teller effect, MnIII shows elongated octahedral coordination with ferrodistortive ordering along the chain direction. The distortion is remarkably higher in ( 1 ) than in ( 2 ). This is discussed in context with additional hydrogen bonds along the chain in ( 2 ).  相似文献   

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