Building three-dimensional metal phosphites from the corner-shared four-membered rings chain

Three new compounds, a one-dimensional (1D) zinc phosphite, (C₄H₈N₂H₄)[Zn(HPO₃)₂] (I), two three-dimensional (3D) metal phosphites (C₄H₈N₂H₄)[Zn₃(HPO₃)₄] (II) and (C₄H₈N₂H₄)[Zn_(3−x)Co_x(HPO₃)₄(H₂O)₂] (x≈0.83) (III) have been synthesized under hydrothermal conditions templated by piperazine and characterized by single-crystal X-ray diffraction, XRD, IR, UV-vis spectra and SQUID magnetometer. Compound I displays 1D chain-like structure, containing corner-shared (cs) four-membered rings. Interestingly, the structures of II and III show 1D chains similar to those observed in I. It is noteworthy that III represents the first cobalt-substituted zinc-phosphite. Crystal data: I, monoclinic, C2/c, a=17.748(2) Å, b=7.428(9) Å, c=8.8071(11) Å, β=105.345(3)°, V=1091.9 Å³, Z=4. II, Monoclinic P2₁/c, a=9.9435(4) Å, b=10.1438(3) Å, c=17.8164(5) Å, β=95.665(2)°, V=1788.27 Å³, Z=4, and III, Monoclinic P2₁/c, a=7.2338(2) Å, b=15.0238(5) Å, c=9.2153(3) Å, β=107.741(2)°, V=953.88(5) Å³, Z=2.     

Os(CO)2(η-SC5H4N(O))(η-SC5H4N): structural evidence for the transformation of pyridine-2-thione N-oxide to pyridine-2-thiolate in osmium complexes

The reaction of Os₃(CO)₁₂ with an excess of 1-hydroxypyridine-2-thione and Me₃NO gives three mononuclear osmium complexes Os(CO)₂(η²-SC₅H₄N(O))₂ (1), Os(CO)₂(η²-SC₅H₄N(O))(η²-SC₅H₄N) (2), and Os(CO)₂(η²-SC₅H₄N)₂ (3). The results of single-crystal X-ray analyses reveal that complex 1 contains two O,S-chelate pyridine-2-thione N-oxide (PyOS) ligands, whereas complex 2 contains one O,S-chelate PyOS and one N,S-chelate pyridine-2-thiolate group. The unique structure of 2 provides evidence of the pathway for this transformation. When this reaction was monitored by ¹H NMR spectroscopy the triosmium complexes Os₃(CO)₁₀(μ-H)(μ-η¹-S-C₅H₄N(O)) (4) and Os₃(CO)₉(μ-H)(μ-η¹:η²-SC₅H₄N(O)) (5) were identified as intermediates in the formation of the mononuclear final products 1-3. The proposed pathway is further supported by the observation of several dinuclear osmium intermediates by electrospray ionization mass spectrometry. In addition, the reaction of Os₃(CO)₁₂ with 1-hydroxypyridine-2-thione in the absence of Me₃NO at 90 °C generated mononuclear complex 2 as the major product along with smaller amounts of complexes 1 and 3. These results suggest that the N-oxide facilitates the decarbonylation reaction. Crystal data for 1: monoclinic, space group C2/c, a = 26.9990(5) Å, b = 7.6230(7) Å, c = 14.2980(13) Å, β = 101.620(2)°, V = 2882.4(4) ų, Z = 8. Crystal data for 2: monoclinic, space group C2/c, a = 5.7884(3) Å, b = 13.9667(7) Å, c = 17.2575(9) Å, β = 96.686(1)°, V = 1385.69(12) ų, Z = 4.     

Two new hydrogen bond-supported supramolecular compounds assembly from polyoxovanadate and organoamines

Two novel organic-inorganic hybrid compounds based on organoamines and polyoxovanadates formulated as (H₂dien)₄[H₁₀V₁₈O₄₂(PO₄)](PO₄)·2H₂O (1) (dien=diethylenetriamine) and (Him)₈[HV₁₈O₄₂(PO₄)] (2) (im=imidazole) have been prepared under hydrothermal conditions by using different starting materials, and characterized by elemental analyses, IR, ESR, XPS, TGA and single-crystal X-ray diffraction analyses. Crystal data for compound 1: C₁₆H₇₄N₁₂O₅₂V₁₈P₂, Monoclinic, space group C2/c, a=23.9593(4) Å, b=13.0098(2) Å, c=20.1703(4) Å, β=105.566(3)°, V=6056.6(19) Å³, Z=4; for compound 2, C₂₄H₄₁N₁₆O₄₆V₁₈P, Tetragonal, space group I4/mmm, a=13.5154(8) Å, b=13.5154(8) Å, c=19.1136 Å, β=90°, V=3491.4(3) Å³, Z=2. Compound 1 consists of protonated diens together with polyoxovanadates [H₁₀V₁₈O₄₂(PO₄)]⁵⁻. Compound 2 is composed of protonated ims and polyoxovanadates [HV₁₈O₄₂(PO₄)]⁸⁻. There are hydrogen-bonding interactions between polyoxovanadates and different organoamines in 1 and 2. Polyoxovanadates are linked through H₂dien into a three-dimensional network via hydrogen bonds in 1, while polyoxovanadates are linked by Him into a two-dimensional layer network via hydrogen bonds in 2. The crystal packing patterns of the two compounds reveal various supramolecular frameworks.     

Ab-initio crystal structure of hydroxy adipate of nickel and hydroxy subarate of nickel and cobalt from synchrotron powder diffraction and magnetic properties

Organic-inorganic hybrid compounds Ni(II)₅(OH)₆(C₆H₈O₄)₂(1), Ni(II)₅(OH)₆(C₈H₁₂O₄)₂(2) and Co(II)₅(OH)₆(C₈H₁₂O₄)₂(3) have a similar layered structure as determined ab initio from synchrotron powder diffraction analysis. The metal sites are octahedrally coordinated by O atoms. The slabs are built from edge-sharing octahedra in such a way that channels with an average size of 4 Å are formed. Bis-bidentate and bridging dicarboxylate anions lead to a 3D framework. The compounds (1) and (2) order antiferromagnetically below T_N=26.5 and 19.3 K, respectively, while (3) is ferrimagnetic with T_C=16.2 K. Crystal data for compounds are as follows: (1)a=11.6504(1) Å, b=6.8021(3) Å, c=6.3603(1) Å, α=73.52(1)°, β=99.69(1)°, γ=96.16(1)°, R_B=0.070, 668 reflections; (2)a=13.9325(1) Å, b=6.7893(1) Å, c=6.3534(4) Å, α=73.63(1)°, β=95.14(1)°, γ=91.80(1)°, R_B=0.052, 804 reflections; (3)a=13.9806(1) Å, b=6.9588(1) Å, c=6.3967(1) Å, α=73.05(1)°, β=94.51(1)°, γ=92.19(1)°, R_B=0.048, 410 reflections. The space group is P−1 for the three compounds.     

Synthesis, structure of [H3dien]·(MF6)·H2O (M=Cr, Fe) and Fe Mössbauer study of [H3dien]·(FeF6)·H2O

Single crystals of [H₃dien]·(FeF₆)·H₂O (I) and [H₃dien]·(CrF₆)·H₂O (II) are obtained by solvothermal synthesis under microwave heating. I is orthorhombic (Pna2₁) with a=11.530(2) Å, b=6.6446(8) Å, c=13.787(3) Å, V=1056.3(2) Å³ and Z=4. II is monoclinic (P2₁/c) with a=13.706(1) Å, b=6.7606(6) Å, c=11.3181(9) Å, β=99.38(1)°, V=1034.7(1) Å³ and Z=4. The structure determinations, performed from single crystal X-ray diffraction data, lead to the R₁/wR₂ reliability factors 0.028/0.066 for I and 0.035/0.102 for II. The structures of I and II are built up from isolated FeF₆ or CrF₆ octahedra, water molecules and triprotonated amines. In both structures, each octahedron is connected by hydrogen bonds to six organic cations and two water molecules. The iron-based compound is also characterized by ⁵⁷Fe Mössbauer spectrometry: the hyperfine structure confirms the presence of Fe³⁺ in octahedral coordination and reveals the existence of paramagnetic spin fluctuations.     

The first di-cadmium-substituted vanadoarsenate derived from α-{As8V14O42} shell

Two di-cadmium-substituted vanadoarsenates, [Cd(enMe)₃]₂{α-[(enMe)₂Cd₂As₈V₁₂O₄₀(0.5H₂O)]}·5.5H₂O (1, enMe=1,2-diaminopropane) and [Cd(enMe)₂]₂{β-[(enMe)₂Cd₂As₈V₁₂O₄₀(0.5H₂O)]} (2), were hydrothermally synthesized and characterized by elemental analyses, IR, TGA, UV-Vis, XRD, magnetic measurements and single crystal structural analyses. Crystal data for 1: monoclinic, P2(1)/c, a=15.040(9) Å, b=20.288(12) Å, c=27.873(17) Å, β=98.046(8)°, V=8421.3(19) Å³, Z=4; for 2: monoclinic, P2(1)/n, a=12.753(3) Å, b=19.334(5) Å, c=14.310(3) Å, β=99.984(3)°, V=3475.1(14) Å³, Z=2. X-ray diffraction analyses reveal that compounds 1 and 2 exhibit isolated and one-dimensional inorganic-organic hybrid structures, respectively. The former is the first di-cadmium-substituted vanadoarsenate derived from α-{As₈V₁₄O₄₂} shell, while the latter is another kind of di-cadmium-substituted vanadoarsenate derived from β-{As₈V₁₄O₄₂} shell. Variable temperature susceptibility measurements demonstrate the presence of antiferromagnetic interactions between V^IV cations in 1 and 2.     

Hydrothermal syntheses and structures of the uranyl tellurates AgUO2(HTeO5) and Pb2UO2(TeO6)

Two uranyl tellurates, AgUO₂(HTeO₅) (1) and Pb₂UO₂(TeO₆) (2), were synthesized under hydrothermal conditions and were structurally, chemically, and spectroscopically characterized. 1 crystallizes in space group Pbca, a=7.085(2) Å, b=11.986(3) Å, c=13.913(4) Å, V=1181.5(5) Å³, Z=8; 2 is in P2(1)/c, a=5.742(1) Å, b=7.789(2) Å, c=7.928(2) Å, V=90.703(2) Å³, and Z=2. These are the first structures reported for uranyl compounds containing tellurate. The U⁶⁺ cations are present as (UO₂)²⁺ uranyl ions that are coordinated by O atoms to give pentagonal and square bipyramids in compounds 1 and 2, respectively. The structural unit in 1 is a sheet consisting of chains of edge-sharing uranyl pentagonal bipyramids that are one bipyramid wide, linked through the dimers of TeO₆ octahedra. In 2, uranyl square bipyramids share each of their equatorial vertices with different TeO₆ octahedra, giving a sheet with the autunite-type topology. Sheets in 1 and 2 are connected through the low-valence cations that are located in the interlayer region. The structures of 1 and 2 are compared to those of uranyl compounds containing octahedrally coordinated cations.     

An unprecedented extended architecture constructed from a 2-D interpenetrating cationic coordination framework templated by SiW12O40 anion

A novel inorganic-organic hybrid compound based on polyoxometalates (POMs) and organic ligand formulated as [Cu₂(bpp)₄(H₂O)₂](SiW₁₂O₄₀)∼6H₂O (1) [bpp=1,3-bis(4-pyridyl)propane], was hydrothermally synthesized and structurally characterized by elemental analysis, single-crystal X-ray diffraction analysis, IR, TG, and cyclic voltammetry. Crystal data for 1: Orthorhombic, Pbcn, a=23.0085(19) Å, b=14.6379(12) Å, c=23.6226(19) Å, V=7956.0(11) Å³, Z=4, Dc=3.315 g cm^-3, and R(final)=0.0826. X-ray diffraction study reveals that compound 1 was the first interpenetrating network of 2-D metal-organic cationic coordination framework [Cu₂(bpp)₄(H₂O)₂]_n⁴ⁿ⁺, in which Keggin-type anions SiW₁₂O₄₀^4- has been used as a non-coordinating anionic template. The electrochemical property of 1-bulk modified carbon paste electrode (1-CPE) has been studied, and the results indicate that 1-CPE has good electrocatalytic activities toward the reduction of nitrite in 1 M H₂SO₄ aqueous solution.     

Hydrothermal synthesis, crystal structure, thermal behavior and spectroscopic and magnetic properties of two new organically templated fluoro-vanadyl-hydrogenarsenates: (R)0.5[(VO)(HAsO4)F] (R: Ethylenediammonium and piperazinium)

Two new fluoro-vanadyl-hydrogenarsenate compounds templated by ethylenediamine and piperazine with formula, (C₂N₂H₁₀)_0.5[(VO)(HAsO₄)F] (1) and (C₄N₂H₁₂)_0.5[(VO)(HAsO₄)F] (2), respectively, have been synthesized by using mild hydrothermal conditions under autogenous pressure. The crystal structures have been solved from single-crystal X-ray diffraction data. The phases crystallize in the P2₁/c monoclinic space group with the unit-cell parameters a=7.8634(4) Å, b=7.7658(4) Å, c=10.4195(6) Å, β=101.524(5)° for compound (1) and a=6.301(1) Å, b=10.244(1) Å, c=10.248(1) Å and β=95.225(1)° for compound (2). These phases exhibit a layered inorganic framework. In both cases, the structure is built from secondary building units (SBU) which are formed by [V₂O₈F₂] edge-shared dimeric vanadyl octahedra, connected by the vertices to two hydrogenarsenate tetrahedra. The repetition of this SBU unit originates sheets along the [1 0 0] direction. The ethylenediammonium and piperazinium cations are located inside the interlayer space. The limit of thermal stability for compounds (1) and (2) is, approximately, 250 and 230 °C, respectively. Near this temperature, both phases loose their organic cations and the fluoride anions. The diffuse reflectance spectra confirm the presence of vanadyl ions, in which the vanadium(IV) cations have a d¹ electronic configuration in a slightly distorted octahedral environment. ESR spectra of both phases are isotropic with mean g-values of 1.93 and 1.96 for ethylendiamine and piperazine phases, respectively. Magnetic measurements for (1) and (2) indicate the existence of antiferromagnetic exchange couplings.     

Synthesis of tungsten compounds with Schiff base ligands prepared from ferrocenecarboxaldehyde: Observation of the migration of an imine double bond

The one-pot reactions of ferrocenecarboxaldehyde, W(CO)₄(pip)₂ (pip = piperidine) and either 2-(aminomethyl)pyridine or 2-(2-aminoethyl)pyridine lead to clean formation of pyridine imine products W(CO)₄(η²-NC₅H₄CHNCH₂C₅H₄FeCp) (1) and W(CO)₄(η²-NC₅H₄C₂H₄NCHC₅H₄FeCp) (2), respectively. Crystal structures of the two compounds show that in 1 the imine double bond has migrated so that it is conjugated with the pyridine ring while in 2 the imine double bond remains conjugated with the cyclopentadienyl ring. This finding is reinforced by a comparison of dihedral angles in each molecule. IR, NMR and electronic spectra each highlight the differences between the two compounds. Crystal data for C₂₁H₁₆FeN₂O₄W (1): monoclinic P2(1)/c, a = 12.768(2) Å, b = 13.593(2) Å, c = 12.981(2) Å, β = 119.46°, V = 1961.6(4) Å³, Z = 4; C₂₂H₁₈FeN₂O₄W (2): monoclinic P2(1)/c, a = 16.759(1) Å, b = 8.8612(7) Å, c = 13.802(1) Å, β = 95.998(1)°, V = 2038.4(3) Å³, Z = 4.     

Two one-dimensional mono-substituted heteropolytungstates based on Keggin anion units

Two kinds of complexes [Ni(DETA)₂]₃[SiNiW₁₁O₃₉]·2.5H₂O (DETA=diethylenetriamine) (1) and [H₂en]₂[Ba_0.15(H₂O)₂(Hen₂)]H_1.7[SiNaW₁₁O₃₉]·2H₂O (2) were obtained from the hydrothermal reaction and characterized by single crystal X-ray diffraction analysis and IR spectra. Crystal data: C₂₄H₈₃N₁₈Ni₄O_41.5SiW₁₁ (1), monoclinic, Pn, a=10.926(2) Å, b=23.022(5) Å, c=13.221(3) Å, β=94.27(3)°, V=3316.4(11) Å³, Z=2; C₈H_46.7N₈Ba_0.15NaO₄₃SiW₁₁ (2), monoclinic, P2₁, a=12.840(3) Å, b=11.174(2) Å, c=16.693(3) Å, β=91.14(3)°, V=2394.4(8) Å³, Z=2. Both of them consists of one mono-substituted Keggin unit [SiMW₁₁O₃₉]⁽⁸⁻ⁿ⁾⁻ (MNi, Na, n=2, 1) obtained by metal atom substituting for a W atom from the plenary anion [SiW₁₂O₄₀]⁴⁻. This unit then connects with other adjacent units via M-O-W bridges constructing an infinitely one-dimensional chain-like structure in which the metal cation and polyanion alternate. Moreover, both of Ni or Na atoms are in a distorted octahedral environment with six oxygen atoms and occupy one position in the oxometalate shell of the Keggin structure.     

Cation-controled formation of N,N′-dialkylimidazolium cadmium-thiocyanate complexes: synthesis and structural characterization

Three new N,N′-dialkylimidazolium salts of cadmium-thiocyanate, [EtMeIm]₂[Cd₂(SCN)₆] (2), [C₆H₄(CH₂ImMe)₂][Cd(SCN)₄] (3), [C₆Me₃(CH₂ImMe)₃][CdBr₃(SCN)](NO₃) (4) have been prepared, and their crystal structures have been determined by X-ray diffraction. Crystal data: 2, monoclinic, C2/c, a=18.349(4) Å, b=7.8667(18) Å, c=21.399(5) Å, β=110.346(4)°, V=2896.1(11) Å³, Z=4, and R1=0.0561; 3, monoclinic, C2/c, a=20.347(7) Å, b=14.029(5) Å, c=9.380(3) Å, β=112.034(6)°, V=2482.1(15) Å³, Z=4, and R1=0.0397; 4, hexagonal, P6₃, a=b=10.7634(8) Å, c=16.0315(17) Å, V=1608.4(2) Å³, Z=2, and R1=0.0569. Compound 2 consists of triply bridged infinite one-dimensional cadmium-thiocyanate chains, and two independent cadmium atoms are octahedrally coordinated in 2N4S and 4N2S geometry, respectively. In 3, the cadmium atom is octahedrally coordinated with two cis N-bonded monodentate NCS⁻ ligands and four bridging SCN⁻ in a S trans to S, and N trans to N coordination fashion, and thus form doubly bridged infinite one-dimensional chains. Whereas 4 is mononuclear, consisting of a discrete [C₆Me₃(CH₂ImMe)₃]³⁺ cation, a nitrate, and [CdBr₃(SCN)]⁻ ion, and each cadmium(II) ion is coordinated to three bromide and one nitrogen atom of SCN⁻ ion. The structures of these compounds are dictated by the imidazolium cations.     

Two isotypic diphosphates LiM2H3(P2O7)2 (M=Ni, Co) containing ferromagnetic zigzag MO6 chains

Two new isotypic phosphates LiNi₂H₃(P₂O₇)₂ (1) and LiCo₂H₃(P₂O₇)₂ (2) have been hydrothermally synthesized and structurally characterized by the single-crystal X-ray diffraction technique. They crystallize in the monoclinic space group C2/c with the lattice: a=10.925(2) Å, b=12.774(3) Å, c=8.8833(18) Å, β=123.20(3)° for 1 and a=10.999(2) Å, b=12.863(3) Å, c=8.9419(18) Å, β=123.00(3)° for 2. The transition metal atoms are octahedrally coordinated, whereas the lithium and phosphorus atoms are all tetrahedrally coordinated. As the lithium-induced derivatives of MH₂P₂O₇ (M=Ni, Co), 1 and 2 possess the same structure with MH₂P₂O₇ in terms of topology, comprising the MO₆ zigzag chains and P₂O₇ as the interchain groups. The magnetisms of 1 and 2 could be interpreted by adopting a quasi-one-dimensional (1D) zigzag chain model as that in their parent compounds: both 1 and 2 have ferromagnetic (FM) NiO₆/CoO₆ chains; 1 shows a FM cluster glass behavior at low temperatures, which is originated from the possible antiferromagnetic (AFM) next-nearest-neighbour intrachain interactions; 2 shows a AFM ordering at T_N=2.6 K and a metamagnetic transition at H_C=4.2 kOe at 1.8 K.     

Hydrothermal synthesis, crystal structure and properties of 2-D and 3-D lanthanide sulfates

Two new lanthanum sulfates DySO₄(OH) 1 and Eu₂(SO₄)₃(H₂O)₈2 have been hydrothermally synthesized. The colorless crystals were characterized by IR, TGA, ICP and XRD. The structure was determined by single-crystal X-ray diffraction. 1 crystallizes with monoclinic symmetry, space group P2(1)/n [a=7.995(4) Å, b=10.945(5) Å, c=8.164(4) Å, α=90°, β=93.619(6)°, γ=90°, V=713.0(5) Å³, Z=8]. It displays a three-dimensional framework, based on the novel Dy-O chains connected by the sulfate groups through helical chains. 2 crystallizes with monoclinic symmetry, space group C2/c, [a=13.5605(17) Å, b=6.7676(8) Å, c=18.318(2) Å, α=90°, β=102.265(2)°, γ=90°, V=1642.7 (4) Å³, Z=4]. Its layered framework is attained by the europium atoms connected by the sulfate groups arranged in a helical manner.     

Two unprecedented 1D coordination polymer chains based on tetranuclear copper(II) building blocks

The reaction of copper(II) sulfate with pyridine in DMF or methanol yield two unprecedented Cu(II) coordination polymers {[Cu₄(μ₄-O)(py)₄(SO₄)₄][μ-Cu(py)(DMF)₂]}_n(1) and {[Cu₄(μ₄-O)(py)₄(SO₄)₄][μ-Cu(py)₄]}_n(2), respectively. Single-crystal X-ray diffraction indicated that compound 1 crystallizes in the monoclinic system, space group p2(1)/n, a=14.542(5) Å, b=16.359(5) Å, c=18.951(5) Å, β=92.047(5)°, V=4505(2) Å³, Z=4 while 2 is monoclinic C2/c, a=23.078(5) Å, b=10.214(5) Å, c=23.142(5) Å, β=115.471(5)°, V=4925(3) Å³, Z=4. Both of the two compounds consist of tetrahedral tetranuclear [Cu₄(μ₄-O)(py)₄(SO₄)₄] clusters that are bridged by pentacoordinated Cu atom for 1 or hexacoordinated Cu atoms for 2 through the sulfate oxygen to form the infinite one-dimensional polymer chains.     

Effect of synthetic conditions on the structures of silver(I)-hexamethylenetetramine coordination polymers: crystal structures of two three-dimensional frameworks featuring new topological motifs

Two novel coordination complexes, [Ag₃(μ₄-hmt)₂(μ-ssa)(H₂O)](NO₃)·3H₂O 1, and [Ag₈(μ₃-hmt)₂(μ₄-hmt)₂(μ-pma)₂(μ-H₂O)₃]·18H₂O 2 (hmt=hexamethylenetetramine, ssa=sulfosalicylate and pma=1,2,4,5-benzenetetracarboxylate), have been prepared and structurally characterized. Crystal data: 1 C₁₉H₃₃Ag₃N₉O₁₃S, orthorhombic, Pna2₁, a=20.483(7) Å, b=21.890(1) Å, c=6.493(2) Å, V=2911.3(13) Å³, Z=4; 2 C₄₄H₉₄Ag₈N₁₆O₃₇, monoclinic, C2/c, a=32.099(10) Å, b=12.916(3) Å, c=21.431(8) Å, β=126.74(1)°, V=7120(4) Å³, Z=4. Both complexes exhibit unprecedented and different topological motifs of Ag-hmt networks. Complex 1 is a novel three-dimensional cationic network with two types of channels, in which the larger one is the largest one in Ag-hmt networks; while 2 is a three-dimensional network with cylindrical channels, consisting of mixed μ₃- and μ₄-hmt ligands. The results demonstrate that under different synthetic conditions, such as the presence of multiple small counter anions or different pH values, different Ag-hmt linkages may be formed to generate new three-dimensional networks.     

A group of new selenite-chlorides of strontium and d-metals (Co,Ni): Synthesis, thermal behavior and crystal chemistry

The new selenite-chlorides with composition Sr₃(SeO₃)₂Cl₂ (I) and Sr₂M(SeO₃)₂Cl₂ (M=Co, Ni (II and III)) were obtained. They crystallize in monoclinic system I: space group C2/m, a=13.203(2) Å, b=5.5355(8) Å, c=6.6170(10) Å, β=95.89(1)°, Z=2; II Space group P2₁/n, a=5.3400(10) Å, b =6.4279(6) Å, c=12.322(1) Å, β=92.44(1)°, Z=2; III: space group P2₁/n, a=5.3254(11) Å, b=6.4363(13) Å, c=12.197(2), β=92.53(3)°, Z=2. All three compounds are constructed in the same manner. Sr polyhedra form infinite layers, which are interconnected into a 3D framework by means of Sr polyhedra in the case of I or Co and Ni polyhedra in the case of II and III. Se atoms are situated inside the channels of the 3D framework. The topological analysis of ELF for I confirmed that the lone electron pairs of SeO₃ groups are located inside these channels.     

Extended chains via hydrogen bond linkages of dinuclear copper(II) and cadmium(II) complexes with a new flexible disulfoxide ligand

A new flexible disulfoxide ligand 1,6-bis(benzylsulfinyl)hexane (L), which is a mixture of the meso and rac isomers, was treated with Cu^II or Cd^II nitrate and obtained dimeric complex [Cu₂(L)₃(H₂O)₂(NO₃)₄] 2 or [Cd₂(L)₃(H₂O)₂(NO₃)₄] 3. In the reacting system the crystals of meso isomer 1 of L together with 2 or 3 were obtained. 2 and 3 have similar molecular structures. In the neutral dimer, three ligands present two kinds of coordination models: monodentate and bis-monodentate. The neutral dimeric units in 2 and 3 are linked by hydrogen bonds to yield a chain structure. Crystal structures of all three compounds were determined by single-crystal X-ray diffraction methods. Crystal data for 1: monoclinic, space group Cc, a=41.95(2), b=5.132(2), c=8.660(4) Å, β=94.898(9)°, V=1857.7(15) Å³, Z=4, final refinement (I>2σ(I)): R1=0.0659, wR2=0.1415. Crystal data for 2: triclinic, space group P-1, a=9.242(4), b=9.539(4), c=21.042(9) Å, α=83.888(9), β=87.971(8), γ=74.177(9)°, V=1774.6(13) Å³, Z=2, final refinement (I>2σ(I)): R1=0.0577, wR2=0.0954. Crystal data for 3: triclinic, space group P-1, a=9.203(4), b=9.831(3), c=20.860(7) Å, α=84.313(6), β=86.432(7), γ=74.188(6)°, V=1805.9(11) Å³, Z=2, final refinement (I>2σ(I)): R1=0.0548, wR2=0.1192.     

Synthesis and characterization of two novel pyridine-containing framework gallium ethylenediphosphonates

Two novel gallium diphosphonates, (C₅H₅N)Ga₃F(O₃PC₂H₄PO₃)₂ (I) (triclinic, P-1, a=8.2880(12) Å, b=11.7197(16) Å, c=11.7601(17) Å, α=71.589(3)°, β=70.577(3)°, γ=77.313(3)°, V=1013.7(2) Å³, Z=2, R₁=0.0352, wR₂=0.0980) and (C₅H₅NH)₂[Ga₄F₂(O₃PC₂H₄PO₃)₃] (II) (triclinic, P-1, a=8.670(4) Å, b=9.742(3) Å, c=10.406(2) Å, α=81.44(3)°, β=65.83(5)°, γ=67.16(3)°, V=739.0(4) Å³, Z=2, R₁=0.0600, wR₂=0.1495) have been synthesised by solvothermal methods in the presence of pyridine and their structures determined using single-crystal X-ray diffraction data. Both compounds I and II are composed of various Ga-centered polyhedra and ethylenediphosphonate groups that link together to form framework materials with one- and two-dimensional channel systems, respectively. The two structures are formed in the presence of structure-directing pyridine molecules that are directly bound to some of the Ga atoms in I, and are protonated as pyridinium cations in II. Compounds I has a charge-neutral framework, while compound II has an anionic framework. Both materials provide rare examples of organically structure-directed framework metal diphosphonate materials.     

Hydrothermal synthesis and characteristics of 3-D hydrated bismuth oxalate coordination polymers with open-channel structure

Two new 3-D porous bismuth coordination polymers, (C₅NH₆)₂[Bi₂(H₂O)₂(C₂O₄)₄]·2H₂O 1 and (NH₄)[Bi(C₂O₄)₂]·3H₂O 2, have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic symmetry, P2₁/c space group with a=10.378(2) Å, b=17.285(3) Å, c=16.563(5) Å, α=90°, β=119.66(2)°, γ=90°, V=2581.8(10) Å³, Z=4, R₁=0.0355 and wR₂=0.0658 for unique 4713 reflections I >2σ(I). Compound 2 crystallizes in the tetragonal symmetry, I4₁/amd space group with a=11.7026(17) Å, b=11.7026(17) Å, c=9.2233(18) Å, α=90°, β=90°, γ=90°, V=1263.1(4) Å³, Z=32, R₁=0.0208 and wR₂=0.0518 for unique 359 reflections I> 2σ(I). Compounds 1 and 2 are 3-D open-framework structures with a 6⁶ uniform net, which consist of honeycomb-like layers connected to each other by oxalate units. While different guest molecules fill in their cavities of honeycomb-like layers, study of ultrasonic treatment on 2 indicates the replacement of NH₄⁺ by K⁺ on potassium ion exchange. Thermogravimetric analysis indicates that the open-channel frameworks are thermally stable up to 200 °C, and other characterizations are also described by elemental analysis, IR and ultraviolet-visible diffuse reflectionintegral spectrum (UV-Vis DRIS).