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1.
The scandium(III) cations in the structures of pentaaqua(biuret‐κ 2O, O′)scandium(III) trichloride monohydrate, [Sc(C 2H 5N 3O 2)(H 2O) 5]Cl 3·H 2O, (I), and tetrakis(biuret‐κ 2O, O′)scandium(III) trinitrate, [Sc(C 2H 5N 3O 2) 4](NO 3) 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 Sc 3+ 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 Sc 3+ 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
2.
>From Small Fragments to New Poly‐alkoxo‐oxo‐metalate Derivatives: Syntheses and Crystal Structures of K 4[V IV12O 12(OCH 3) 16(C 4O 4) 6], Cs 10[V IV24O 24(OCH 3) 32(C 4O 4) 12][V IV8O 8(OCH 3) 16(C 2O 4)], and M 2[V IV8O 8(OCH 3) 16(V IVOF 4)] (M = [N( nBu) 4] or [NEt 4]) By solvothermal reaction of ortho‐vanadicacid ester [VO(OMe) 3] with squaric acid and potassium or caesium hydroxide the compounds K 4[V IV12O 12(OCH 3) 16(C 4O 4) 6] ( 2 ) and Cs 10[V IV24O 24(OCH 3) 32(C 4O 4) 12][V IV8O 8(OCH 3) 16(C 2O 4)] ( 3 ) could be syntesized. With tetra‐ n‐butyl‐ or tetra‐ n‐ethylammonium fluoride [N(nBu) 4] 2[V IV8O 8(OCH 3) 16(V IVOF 4)] ( 4 ) and [N(Et) 4] 2[V IV8O 8(OCH 3) 16(V IVOF 4)] ( 5 ) could be isolated. In 2 and 3 the corners of a tetrahedron or cube resp. are occupied by {(VO) 3(OMe) 4} groups and connected along the edges of the tetrahedron resp. cube by six or twelve resp. squarato‐groups. The octanuclear anions in the compounds 3 , 4 , and 5 are assumedly built up by fragments of the ortho‐vanadicacid ester [VO(OMe) 3]. Around the anions C 2O 42— or VOF 4— these oligormeric chains are closed to a ring . Crystal data: 2 , tetragonal, P4 3, a = 18.166(3)Å, c = 29.165(7)Å, V = 9625(3)Å 3, Z = 4, dc = 1.469 gcm —3; 3 , orthorhombic, Pbca, a = 29.493(5)Å, b = 25.564(4)Å, c = 31.076Å, V = 23430(6)Å 3, Z = 4, dc = 1.892 gcm —3; 4 , monoclinic, P2 1/ n, a = 9.528(1)Å, b = 23.021(2)Å, c = 19.303(2)Å, β = 92.570(2)°, V = 4229.8(5)Å 3, Z = 2, dc = 1.391 gcm —3; 5 , monoclinic, P2 1/ n, a = 16.451(2)Å, b = 8.806(1)Å, c = 23.812(1)Å, β = 102.423(2)°, V = 3368.7(6)Å 3, Z = 2, dc = 1.534 gcm —3. 相似文献
3.
V IV oxyfluorides are of interest as frustrated magnets. The successful synthesis of two‐dimensionally connected vanadium(IV) oxyfluoride structures generally requires the use of ionic liquids as solvents. During solvothermal synthesis experiments aimed at producing two‐ and three‐dimensional vanadium(IV) selenites with triangular lattices, the title compound, diaquatetra‐μ‐fluorido‐dioxidodivanadium(IV) monohydrate, V 2O 2F 4(H 2O) 2·H 2O, was discovered and features a new infinite V 4+‐containing two‐dimensional layer comprised of fluorine‐bridged corner‐ and edge‐sharing VOF 4(H 2O) octahedral building units. The synthesis was carried out under solvothermal conditions. The V 4+ centre exhibits a typical off‐centring, with a short V=O bond and an elongated trans‐V—F bond. Hydrogen‐bonded water molecules occur between the layers. The structure is related to previously reported vanadium oxyfluoride structures, in particular, the same layer topology is seen in VOF 3. 相似文献
4.
Polyoxometalates (POMs)containingKegginmoi etieshavebeenreceivingextensiveattentioninrecentyearsowingtotheirgreatfundamentalandpracticalinter est .1Especiallytheunusualelectronicproperty (highnegativecharges) ,oneofthemostimportantpropertiesofPOMs ,haspoten… 相似文献
5.
Two germanato‐polyoxovanadates with the {V 15Ge 6O 48} cluster core are extended by covalent bonds to four transition metal amine complexes [ M(tren)] 2+ ( M = Co and Zn, tren = tris(2‐aminoethyl)amine). The complexes have bonds to terminal atoms of the Ge 2O 7 units and such expansion of a germanato‐polyxovanadate was never observed before. The characterization of these compounds revealed the presence of two protonated tren molecules charge balancing the negative charges of the [{ M(tren)} 4V 15Ge 6O 48(H 2O)] 4– anion. 相似文献
6.
Two novel As‐V‐O cluster supported transition metal complexes, [Zn(en) 2][Zn(en) 2(H 2O) 2][{Zn(en)(enMe)}As 6V 15O 42(H 2O)]·4H 2O ( 1 ) and [Zn 2(enMe) 2(en) 3][{Zn(enMe) 2}As 6V 15O 42(H 2O)]·4H 2O ( 2 ), have been hydrothermally synthesized. The single X‐ray diffraction studies reveal that both compounds consist of discrete noncentral polyoxoanions [{Zn(en)(enMe)}As 6V 15O 42(H 2O)] 4? or [{Zn(enMe) 2}As 6V 15O 42(H 2O)] 4? cocrystallized with respective zinc coordination complexes. Interestingly, compounds 1 and 2 exhibit the first two polyoxovanadates containing As 8V 15O 42‐(H 2O)] 6? cluster decorated by only one transition metal complex. Crystal data: 1 , monoclinic, P2 1/n, a = 14.9037(4) Å, b = 18.1243(5) Å, c = 27.6103(7) Å, β = 105.376(6)°, Z = 4; 2 monoclinic, P2 1/n, a = 14.9786(7) Å, b = 33.0534(16) Å, c = 14.9811(5) Å, Z = 4. 相似文献
7.
The single crystals of (C 2H 7N 4O) 2[UO 2(C 2O 4) 2(H 2O)] 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) Å 3. The main structural units of the crystals of I are islet complex groups [UO 2(C 2O 4) 2(H 2O)] 2? corresponding to the crystal chemical group AB 2 01 M 1 (A = UO UO 2 2+ , B 01 = C 2O 4 2? , M = H 2O) 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
8.
Vanadium chemistry is of interest due its biological relevance and medical applications. In particular, the interactions of high‐valent vanadium ions with sulfur‐containing biologically important molecules, such as cysteine and glutathione, might be related to the redox conversion of vanadium in ascidians, the function of amavadin (a vanadium‐containing anion) and the antidiabetic behaviour of vanadium compounds. A mechanistic understanding of these aspects is important. In an effort to investigate high‐valent vanadium–sulfur chemistry, we have synthesized and characterized the non‐oxo divanadium(IV) complex salt tetraphenylphosphonium tri‐μ‐<!?tlsb=‐0.11pt>methanolato‐κ 6O: O‐bis({tris[2‐sulfanidyl‐3‐(trimethylsilyl)phenyl]phosphane‐κ 4P, S, S′, S′′}vanadium(IV)) methanol disolvate, (C 24H 20P)[V IV2(μ‐OCH 3) 3(C 27H 36PS 3) 2]·2CH 3OH. Two V IV metal centres are bridged by three methanolate ligands, giving a C2‐symmetric V 2(μ‐OMe) 3 core structure. Each V IV centre adopts a monocapped trigonal antiprismatic geometry, with the P atom situated in the capping position and the three S atoms and three O atoms forming two triangular faces of the trigonal antiprism. The magnetic data indicate a paramagnetic nature of the salt, with an S = 1 spin state. 相似文献
9.
The title compound, triammonium cis‐diaqua‐ cis‐dioxo‐ trans‐disulfatovanadate 1.5‐hydrate, was obtained by oxidizing V IV to V V in a 2 M sulfuric acid solution of vanadyl sulfate and adding ammonium sulfate. Here, the V atom is sandwiched by two sulfate groups by corner‐sharing to form a discrete [VO 2(SO 4) 2(OH 2) 2] 3? anion. The water molecules occupy cis positions in the equatorial plane of the vanadium octahedron. 相似文献
10.
Crystal Structure of Sodium Dihydrogencyamelurate Tetrahydrate Na[H 2(C 6N 7)O 3] · 4 H 2O Sodium dihydrogencyamelurate‐tetrahydrate Na[H 2(C 6N 7)O 3]·4 H 2O 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) Å 3, 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
11.
A new polymeric copper complex, viz.catena‐poly[[[μ‐ N, N′‐bis(3‐aminopropyl)oxamidato‐κ 6N, N′, O: N′′, N′′′, O′]dicopper(II)]‐di‐μ‐dicyanamido‐1:1′κ 2N1: N5;2:2′κ 2N1: N5], [Cu 2(C 8H 16N 4O 2)(C 2N 3) 2] n or [Cu(oxpn) 0.5{N(CN) 2}] n [where H 2oxpn is N, N′‐bis(3‐aminopropyl)oxamide], has been synthesized by the reaction of Cu(oxpn), [Cu(ClO 4) 2]·6H 2O and NaN 3. In the crystal structure, the Cu atom is five‐coordinate and has a square‐pyrimidal (SP) configuration. In the polymer, dicyanamide (dca −) groups link Cu II cations in a μ‐1,5‐bridging mode, generating novel ladders in which each step is composed of dimeric [Cu 2(oxpn)] 2+ cations. Abundant hydrogen bonds connect the polymer ladders into a two‐dimensional network structure. 相似文献
12.
Summary Two novel charge-transfer (CT) heteropoly complexes, (C 8H 12N 2) 5H 7PMo 12O 40
(1) and (C 8H 12N 2) 3H 3-PMo 12O 40·5H 2O (2), prepared by reacting p-Me 2NC 6H 4NH 2 with the four-electron heteropoly blue H 7PMo 12O 40·12H 2O and heteropoly acid H 3PMo 12O 40· xH 2O, respectively, were characterized by elemental analysis, and u.v., i.r., XPS and e.s.r. spectroscopies. A sizable electron-transfer
interaction occurs within the product molecules and the heteropoly anions retain their Keggin structure. Their third-order
optical non-linearity coefficients were measured using the Z-scan technique at a concentration of 4.68 × 10 −6 mol dm −3 for (1) and 2.79 × 10 −6 mol dm −3 for (2), with I
0 = 2.38 × 10 13 w m −2 and λ = 532nm. The |χ (3)| for (1) is 2.61 × 10 −10 esu and |χ (3)| for (2) is 1.05 × 10 −10 esu. 相似文献
13.
Two new neutral Keggin-polyoxometalate derivatives: [{Co(2,2′-bipy) 2(H 2O)} 2]–[PMo VI7Mo V5O 40(V IVO) 2] (1) and [{Ni(phen) 2(H 2O)} 2](H 3O) [PMo VI10Mo V2O 40] · 4H 2O (2) have been synthesized under hydrothermal conditions and characterized by i.r., t.g. analysis, x.p.s. spectra and single-crystal
X-ray diffraction. In the case of (1), the polyoxoanion cluster [PMo 12O 40] 8− is capped by two vanadium atoms via four bridging oxo groups on two opposite {Mo 4O 4} pits of the Keggin polyoxoanion. Two {Co (2,2′-bipy) 2(H 2O)} fragments are supported on the two vanadium atoms through two terminal oxygen atoms from two vanadium atoms. In (2), two {Ni(phen) 2(H 2O)} 2+ moieties are linked to the molybdophosphate cluster [PMo 12O 40] core to form a neutral bimetallic cluster. Furthermore, through the linkages of π – π stacking interactions and hydrogen bond contacts, extended three-dimensional supramolecular networks in the solid of (1) and (2) were formed. 相似文献
14.
Complex [(O)VIV(C2O4)(Phen)(H2O)] was obtained on the basis of V2O5 and malic acid in the presence of concentrated HNO3 and phenanthroline. Its structure was determined by the X-ray structural analysis; its magnetic susceptibility was measured. The role of the \(\rm{VO}^+_2\) and VO2+ cations in the oxidation and complex-formation processes was considered. A method for the conversion of malic acid to oxalate anions through the formation of oxaloacetic acid and the intermediate products of its decarboxylation reactions was proposed. It was shown by the DFT M06/6-31G(d,p) method that the transition state energy decreases in the way of the HOC(O)C(0)CH2-COOH bond breakage during decarboxylation compared with the free acid in the intermediate of its anion with VO2+. 相似文献
15.
[Mn(H 2O) 4(C 4N 2H 4)][C 6H 4(COO) 2] – An One‐Dimensional Coordination Polymer with Chain‐like [Mn(H 2O) 4(C 4N 2H 4)] n2n+ Polycations Orthorhombic single crystals of [Mn(H 2O) 4(C 4N 2H 4)][C 6H 4(COO) 2] have been prepared in aqueous solution at room temperature. Space group Imm2 (no. 44), a = 1039.00(6) pm, b = 954.46(13) pm, c = 737.86(5) pm, V = 0.73172(12) nm 3, Z = 2. Mn 2+ is coordinated in a octahedral manner by four water molecules and two nitrogen atoms stemming from the pyrazine molecules (Mn–O 215.02(11) pm; Mn–N 228.7(4), 230.7(4) pm). Mn 2+ and pyrazine molecules form chain‐like polycations with [Mn(H 2O) 4(C 4N 2H 4)] n2n+ composition. The positive charge of the polycationic chains is compensated for by phthalate anions, which are accomodated between the chains. The phthalate anions are linked by hydrogen bonds to the polycationic chains. Thermogravimetric analysis in air revealed that the loss of water of crystallisation and pyrazine occurs in two steps between 130 and 245 °C. The resulting sample was stable up to 360 °C. Further decomposition yielded Mn 2O 3. 相似文献
16.
Diaquabis[dihydrogen 1‐hydroxy‐2‐(imidazol‐3‐ium‐1‐yl)ethylidene‐1,1‐diphosphonato‐κ 2O, O′]magnesium(II), [Mg(C 5H 9N 2O 7P 2) 2(H 2O) 2], consists of isolated dimeric units built up around an inversion centre and tightly interconnected by hydrogen bonding. The Mg II cation resides at the symmetry centre, surrounded in a rather regular octahedral geometry by two chelating zwitterionic zoledronate(1−) [or dihydrogen 1‐hydroxy‐2‐(imidazol‐3‐ium‐1‐yl)ethylidene‐1,1‐diphosphonate] anions and two water molecules, in a pattern already found in a few reported isologues where the anion is bound to transition metals (Co, Zn and Ni). catena‐Poly[[aquacalcium(II)]‐μ 3‐[hydrogen 1‐hydroxy‐2‐(imidazol‐3‐ium‐1‐yl)ethylidene‐1,1‐diphosphonato]‐κ 5O: O, O′: O′, O′′], [Ca(C 5H 8N 2O 7P 2)(H 2O)] n, consists instead of a Ca II cation in a general position, a zwitterionic zoledronate(2−) anion and a coordinated water molecule. The geometry around the Ca II atom, provided by six bisphosphonate O atoms and one water ligand, is that of a pentagonal bipyramid with the Ca II atom displaced by 0.19 Å out of the equatorial plane. These Ca II coordination polyhedra are `threaded' by the 2 1 axis so that successive polyhedra share edges of their pentagonal basal planes. This results in a strongly coupled rhomboidal Ca 2–O 2 chain which runs along [010]. These chains are in turn linked by an apical O atom from a –PO 3 group in a neighbouring chain. This O‐atom, shared between chains, generates strong covalently bonded planar arrays parallel to (100). Finally, these sheets are linked by hydrogen bonds into a three‐dimensional structure. Owing to the extreme affinity of zoledronic acid for bone tissue, in general, and with calcium as one of the major constituents of bone, it is expected that this structure will be useful in modelling some of the biologically interesting processes in which the drug takes part. 相似文献
17.
The crystals of four amine‐templated uranyl oxoselenates(VI), [C 3H 12N 2][(UO 2)(SeO 4) 2(H 2O) 2](H 2O) ( 1 ), [C 5H 16N 2] 2[(UO 2)(SeO 4) 2(H 2O)](NO 3) 2 ( 2 ), [C 4H 12N][(UO 2)(SeO 4)(NO 3)] ( 3 ), and [C 4H 14N 2][(UO 2)(SeO 4) 2(H 2O)] ( 4 ) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amine. The crystal structures of all four compounds have been solved by direct methods from X‐ray diffraction data. The structure of 1 (triclinic, , a = 7.5611(16), b = 7.7650(17), c = 12.925(3) Å, α = 94.605(18), β = 94.405(17), γ = 96.470(17)°, V = 748.8(3) Å 3, R1 = 0.029 for 2769 unique observed reflections) is based upon 0D‐units of the composition [(UO 2) 2(SeO 4) 4(H 2O) 4] 4?. These discrete units are composed from two pentagonal [UO 7] 8? bipyramids linked via [SeO 4] 2? tetrahedra and are unknown in structural chemistry of uranium so far. The structure of 2 (monoclinic, C2/ c, a = 28.916(5), b = 8.0836(10), c = 11.9856(16) Å, β = 110.909(11)°, V = 2617.1(6) Å 3, R1 = 0.035 for 2578 unique observed reflections) contains [(UO 2)(SeO 4) 2(H 2O)] 2? chains of corner‐sharing pentagonal [UO 7] 8? bipyramids and [SeO 4] 2? tetrahedra. The chains run parallel to the c axis and are arranged into layers parallel to (100). In the structure of 3 (monoclinic, C2/ m, a = 21.244(5), b = 7.1092(11), c = 8.6581(18) Å, β = 97.693(17)°, V = 1295.8(4) Å 3, R1 = 0.027 for 1386 unique observed reflections), pentagonal [UO 7] 8? bipyramids share corners with three [SeO 4] 2? tetrahedra each and an edge with a [NO 3] ? anion to form [(UO 2)(SeO 4)(NO 3)] ? chains parallel to the b axis. In the structure of 4 (triclinic, , a = 6.853(2), b = 10.537(3), c = 10.574(3) Å, α = 99.62(3), β = 94.45(3), γ = 100.52(3)°, V = 735.6(4) Å 3, R1 = 0.045 for 2713 unique observed reflections), one symmetrically independent pentagonal [UO 7] 8? bipyramid shares corners with four [SeO 4] 2? tetrahedra to form the [(UO 2)(SeO 4) 2(H 2O)] 2? chains parallel to the a axis. A comparison to related uranyl compounds is given. 相似文献
18.
The crystal structure of monoaquatetra(3,5-dimethylpyrazole)copper(II) nitrate [Cu(C 5H 8N 2) 4(H 2O)]×(NO 3) 2 is determined (Syntex P2 1 automated diffractometer, θ/2θ scan mode within the 2θ range 3–55° at a variable rate, V min=5 deg/min, λMoK α graphite monochromator, 5170/2349 measured/observed I hk1, absorption taken into account experimentally, R aniso=0.069). The parameters of the monoclinic unit cell are as follows: a=23.569(4), b=8.177(2), c=17.250(6) Å, β=121.65(2)°, V=2830(2) Å 3, Z=4C 20H 34CuN 10O 7, d calc=1.388 g/cm 3. The space group P2 1 was chosen by the process of structure solution and refinement. The structure is of island type. The complex cations [CuL 4(H 2O)] 2+ and the (NO 3) ? anions form mixed layers in the planes parallel to (010) at y?0.36 and 0.87. The central atoms of two crystallographically independent complex cations [CuL 4(H 2O)] 2+ are surrounded with five atoms (O H 2 O+4N) with average Cu?O H 2 O and Cu?N distances of 2.23(2) and 2.04(4), respectively, which form distorted trigonal bipyramids. The average bond lengths in the pyrazole rings are the following: N?N=1.40, N?C=1.40, (C?C) ring=1.42, and C ring?C Me=1.50 Å. 相似文献
19.
The binuclear praseodymium(III) complex with N‐(1‐carboxyethylidene)‐salicylhydrazide (C 10H 10N 2O 4, H 2L) was prepared in H 2O‐C 2H 5OH mixed solution, and the crystal structure of [Pr 2L 2(HL) 2(H 2O) 4]·3H 2O·C 6H 6 was determined by X‐ray single crystal diffraction. The crystal complex crystallizes in the triclinic system with space group P‐1, and in the structure each Pr atom is 9‐coordinated by carboxyl O and acyl O and azomethine N atoms of two tridentate ligands to form two stable five‐membered rings sharing one side in keto‐mode and two water molecules. The coordination polyhedron around Pr 3+ was described as a monocapped square antiprism geometry. In an individual molecule, four tridentate ligands were coordinated by two negative univalent (HL) and two bivalent forms (L) respectively. Two negative univalent ligands were coordinated via μ2‐bridging mode. 相似文献
20.
The First Vanadium(III) Borophosphate: Synthesis and Crystal Structure of CsV 3(H 2O) 2[B 2P 4O 16(OH) 4] CsV 3(H 2O) 2[B 2P 4O 16(OH) 4] was prepared under mild hydrothermal conditions (T = 165 °C) from mixtures of CsOH (aq), VCl 3, H 3BO 3, and H 3PO 4 (molar ratio 1 : 1 : 1 : 2). The crystal structure was determined by X‐ray single crystal methods (monoclinic; space group C2/ m, No. 12): a = 958.82(15) pm, b = 1840.8(4) pm, c = 503.49(3) pm; β = 110.675(4)°; Z = 2. The anionic partial structure contains oligomeric units [BP 2O 8(OH) 2] 5–, which are built up by a central BO 2(OH) 2 tetrahedron and two PO 4 tetrahedra sharing common corners. V III is octahedrally coordinated by oxygen of adjacent phosphate tetrahedra and OH groups of borate tetrahedra as well as oxygen of phosphate tetrahedra and H 2O molecules, respectively (coordination octahedra VO 4(OH) 2 and VO 4(H 2O) 2). The oxidation state +3 for vanadium was confirmed by measurements of the magnetic susceptibility. The trimeric borophosphate groups are connected via vanadium centres to form layers with octahedra‐tetrahedra ring systems, which are likewise linked via V III‐coordination octahedra. Overall, a three‐dimensional framework constructed from VO 4(OH) 2 and VO 4(H 2O) 2 octahedra as well as BO 2(OH) 2 and PO 4 tetrahedra results. The structure contains channels running along [001], which are occupied by Cs + in a distorted octahedral coordination (CsO 4(H 2O) 2). 相似文献
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