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 46 毫秒
1.
In the title compound, polymeric potassium N‐(6‐amino‐3,4‐di­hydro‐3‐methyl‐5‐nitro­so‐4‐oxopyrimidin‐2‐yl)­glycyl­gly­cinate hydrate, (K+·C9H11N6O5?·H2O)n, the hexacoordinate K+ cation is linked to five different anions as well as to the water mol­ecule, with K—O distances in the range 2.617 (2)–2.850 (2) Å. Four of the O atoms in each anion coordinate to K centres, one of them acting as a bridging ligand, leading to the formation of nearly square centrosymmetric K2O2 rings. The structure is analysed in terms of (010) metal–ligand sheets linked by [010] chains of fused rings.  相似文献   

2.
In a combined experimental and theoretical approach, the interactions of valinomycin (Val), macrocyclic depsipeptide antibiotic ionophore, with sodium cation Na+ have been investigated. The strength of the Val–Na+ complex was evaluated experimentally by means of capillary affinity electrophoresis. From the dependence of valinomycin effective electrophoretic mobility on the sodium ion concentration in the BGE (methanolic solution of 20 mM chloroacetic acid, 10 mM Tris, 0–40 mM NaCl), the apparent binding (stability) constant (Kb) of the Val–Na+ complex in methanol was evaluated as log Kb = 1.71 ± 0.16. Besides, using quantum mechanical density functional theory (DFT) calculations, the most probable structures of the nonhydrated Val–Na+ as well as hydrated Val–Na+·H2O complex species were proposed. Compared to Val–Na+, the optimized structure of Val–Na+·H2O complex appears to be more realistic as follows from the substantially higher binding energy (118.4 kcal/mol) of the hydrated complex than that of the nonhydrated complex (102.8 kcal/mol). In the hydrated complex, the central Na+ cation is bound by strong bonds to one oxygen atom of the respective water molecule and to four oxygens of the corresponding C=O groups of the parent valinomycin ligand.  相似文献   

3.
From the reduction of heptamolybdate, a polyoxomolybdate was obtained with the formula [Na(H2O)16(NH2CH2­COO)]4+·{Na+[H9MoMoO56(NH2CH2COO)]5?}4?­·20H2O, i.e. hepta­sodium nona­hydrogen tetra­car­bam­ate hexa­deca­aqua­hexa­penta­conta­oxa­octa­deca­molyb­date(V,VI) icosa­hydrate. The 18 Mo atoms are connected by bridging O atoms to form a centrosymmetric girdle‐like structure, in which MoV–MoV units are found. An Na+ cation occupies the central hole of the girdle, while four Na+ cations are bonded to the O atoms on the girdle edge. The girdles are linked into a one‐dimensional chain by the other Na+ cations.  相似文献   

4.
In the title compound, Na+·C6H8NO6?·2H2O, the sodium ion is coordinated in a distorted octahedral manner by two carboxyl­ate O atoms and two water O atoms. Each of these water mol­ecules bridges two adjacent Na ions, resulting in two four‐membered rings of the type Na–O–Na–O.  相似文献   

5.
In the crystal structure of the title hydrated salt, poly[(μ2‐aqua)(μ4‐1‐sulfido‐β‐D‐glucoside)potassium], [K(C6H11O5S)(H2O)]n or K+·C6H11O5S·H2O, each thioglucoside anion coordinates to four K+ cations through three of its four hydroxy groups, forming a three‐dimensional polymeric structure. The negatively charged thiolate group in each anion does not form an efficient coordination bond with a K+ cation, but forms intermolecular hydrogen bonds with four hydroxy groups, which appears to sustain the polymeric structure. The Cremer–Pople parameters for the thioglucoside ligand (Q = 0.575, θ = 8.233° and ϕ = 353.773°) indicate a slight distortion of the pyranose ring.  相似文献   

6.
In the title compound, [Na4(C8H16BO4)4(C4H10O2)]n, there are two coordination types for the four independent Na+ cations: two Na+ cations bond to six diolate O atoms [Na—O = 2.305 (2)–2.609 (2) Å], while the other two are five‐coordinate via one 1,4‐butane­diol [2.289 (2) and 2.349 (3) Å] and four diolate O atoms [2.295 (2)–2.408 (2) Å]. Corresponding to this, there are three‐ and four‐coordinate diolate O atoms, the latter bridging Na atoms. The 1,4‐butane­diol mol­ecules lie on inversion centres. The boron stereochemistry shows minor local perturbations from its usual tetrahedral state [B—O = 1.457 (4)–1.503 (4) Å]. The resulting polymer packs as sheets parallel to the (10) plane crosslinked by the butane­diol mol­ecules. The structure was solved using data from a multiple crystal.  相似文献   

7.
New complex compound, diaqua(18-crown-6)sodium E-2-phenylethenylphosphonate 18-crown-6 E-2-phenylethenylphosphonic acid, [Na(18-crown-6)(H2O)2]+·HO 3 ? PCH=CHPh·18-crown-6·H2O3PCH=CHPh, was obtained and its crystal and molecular structures were studied by the X-ray structural analysis. In this structure the complex cation [Na(18-crown-6)(H2O)2]+ is of guest-host type. The coordination polyhedron of its Na+ cation is a slightly screwed hexagonal bipyramid with the base consisting of all 6 O atoms of 18-crown-6 ligand and with two opposite apexes at two O atoms of two ligand water molecules. In the studied crystal structure the alternating complex cations and 18-crown-6 molecules as well as the molecules of acid and its anion HO 3 ? PCH=CHPh form by means of hydrogen bonds the infinite chains of two different types.  相似文献   

8.
In the title compound, Na+·H+·2C8H7O3, the anion contains a short Speakman-type hydrogen bond [O⃛O = 2.413 (2) Å]. The anions and the Na atoms lie across twofold axes.  相似文献   

9.
The structures of a series of binary molybdates with the lithium cation LiM(MoO4) · H2O (M = K+, Na+, Rb+, NH 4 + ) are analyzed and compared. Except for LiNa(MoO4) · 2H2O, in all other compounds the lithium cations have a tetrahedral coordination formed by the oxygen atoms of the water molecules and molybdate groups. The structure of LiNa(MoO4) · 2H2O was found to contain a unique coordination polyhedron of lithium, i.e., a trigonal bipyramid formed by the O atoms of the water molecules and oxo anions.  相似文献   

10.
Polysulfonylamines. CLXIII. Crystal Structures of Metal Di(methanesulfonyl)amides. 12. The Orthorhombic Double Salt Na2Cs2[(CH3SO2)2N]4·3H2O: A Three‐Dimensional Coordination Polymer Built up from Cesium‐Anion‐Water Layers and Intercalated Sodium Ions The packing arrangement of the three‐dimensional coordination polymer Na2Cs2[(MeSO2)2N]4·3H2O (orthorhombic, space group Pna21, Z′ = 1) is in some respects similar to that of the previously reported sodium‐potassium double salt Na2K2[(MeSO2)2N]4·4H2O (tetragonal, P43212, Z′ = 1/2). In the present structure, four multidentately coordinating independent anions, three independent aquo ligands and two types of cesium cation form monolayer substructures that are associated in pairs to form double layers via a Cs(1)—H2O—Cs(2) motif, thus conferring upon each Cs+ an irregular O8N2 environment drawn from two N, O‐chelating anions, two O, O‐chelating anions and two water molecules. Half of the sodium ions occupy pseudo‐inversion centres situated between the double layers and have an octahedral O6 coordination built up from four anions and two water molecules, whereas the remaining Na+ are intercalated within the double layers in a square‐pyramidal and pseudo‐C2 symmetric O5 environment provided by four anions and the water molecule of the Cs—H2O—Cs motif. The net effect is that each of the four independent anions forms bonds to two Cs+ and two Na+, two independent water molecules are involved in Cs—H2O—Na motifs, and the third water molecule acts as a μ3‐bridging ligand for two Cs+ and one Na+. The crystal cohesion is reinforced by a three‐dimensional network of conventional O—H···O=S and weak C—H···O=S/N hydrogen bonds.  相似文献   

11.
Lagoden (L·3H2O, where L is Na+·C20H33O6; sodium 3β,16,18‐trihydroxy‐8,13‐epi‐9,13‐epoxylabdan‐15‐oate trihydrate) is widely used as an effective haemostatic agent. It has been crystallized from dimethylformamide (DMF) as sodium 3β,16,18‐trihydroxy‐8,13‐epi‐9,13‐epoxylabdan‐15‐oate dimethylformamide hemisolvate dihydrate, Na+·C20H33O6·0.5C3H7NO·2H2O or L2·DMF·4H2O, and the asymmetric unit contains two of the latter formulation. The four symmetry‐independent Na+ cations and lagoden anions, one DMF molecule and six of the eight symmetry‐independent water molecules assemble into a one‐dimensional polymeric structure via dipolar and hydrogen‐bonding interactions. The lagoden anions coordinate to the Na+ cations via the carboxylate groups and the two primary hydroxy groups, whereas the secondary OH groups are solely involved in hydrogen bonding. Two of the four symmetry‐independent lagoden anions act in a chelating mode, forming seven‐membered chelate rings. The absolute structure, based on anomalous dispersion data collected at 130 K with Cu Kα radiation, confirms an inverted configuration at chiral centres C8 and C13 (labdane numbering) relative to the labdane skeleton.  相似文献   

12.
A novel heterotrimetallic complex {[(Dipic)2Cu]4 · Mg(H2O)2Na4(H2O)14 n · nNa2(H2O)10 · 2nCH3OH (H2Dipic = pyridine-2,6-dicarboxylic acid) has been synthesized and structurally determined by X-ray diffraction method. The compound crystallizes in the triclinic system, space group P [`1]\bar 1, with a = 13.5523(13), b = 14.1859(13), c = 14.3213(14) ?, α = 62.6160(10)°, β = 68.2540(10)°, γ = 89.7110(10)°, V = 2224.7(4)?3, F(000) = 1144, M r = 2237.70, Z = 1, ρ c = 1.670 g cm−3, μ = 1.095 mm−1, final R = 0.0507, wR = 0.1418 for 8042 independent reflections with R int = 0.0228. According to the structure determination, the complex is composed of novel one-dimensional (1D) alternating chains, dinuclear Na(I) units, and lattice methanol molecules. The infinite 1D chain structure is built up with many of polymeric [(Dipic)2Cu]4 · Mg(H2O)2Na4(H2O)14 units, which consists of four six-coordinated Cu2+ ions, one six-coordinated Mg2+ ion, two five-coordinated Na+ ions, and two six-coordinated Na+ ions. The 1D alternating chains are linked with another dinuclear Na(I) units by extensive hydrogen bonds to form a three-dimensional (3D) supramolecular structure in which uncoordinated methanol molecules act as space filling particles.  相似文献   

13.
Two Cu(II)–Na(I) hetero-metallic coordination polymers [Cu2Na5(tacntp)2(H2O)9](ClO4)3·2H2O (1) and [Cu2Na5(tacntp)2(H2O)9](ClO4)3·2H2O (2) were constructed from Cu(II) salts and a trisubstituted N-propionic acid functionalized ligand, namely 1,4,7-triazacyclononane-1,4,7-tripropionic acid (tacntpH3). In complex 1, the Na+ ions act as nodes, being surrounded by six [Cu(tacntp)]? moieties resulting in a 2D coordination polymer. In complex 2, Na+ ions are bridged by pendant carboxylate groups and water ligands to give a 1D Na–O inorganic polymeric ribbon, which is expanded into a complicated 2D hetero-metallic array through the connecting [Cu(tacntp)]? units. The differences between the two structures are related to the amount of Na+ ions present in the reaction media. In further experiments, the trisubstituted pro-ligand tacntpH3 underwent a hydrothermal Cu(II)-induced cleavage of one of three pendant arms, and the resultant disubstituted pro-ligand tacndpH2 assembled with Cu(II) to give a 1D homo-metallic zigzag chain compound [Cu(tacndp)]ClO4·H2O (3). Magnetic susceptibility measurements on complex 3 revealed a ferromagnetic interaction between the Cu(II) centers within the 1D chain.  相似文献   

14.
Cluster analysis of the crystal structures of paulingite zeolites (Na,Ca0.5,K,K,Ba0.5)10[Al10Si32O84] · 30H2O (PAU, space group Im [`3]\bar 3 m) has been performed by the tiling method with the TOPOS program package. The tetrahedral T framework of PAU with 672 tetrahedra in the translated unit cell with a = 35.1 ? and V = 43 217 ?3 has been completely decomposed into tiles, complementarily connected polycyclic (polyhedral) T clusters. The zeolite structure is represented by an ensemble consisting of nine geometrically different nanoclusters containing 16 to 48 T tetrahedra (the linear dimensions of the nanoclusters are 12 to 18 ?, respectively). The nanoclusters correspond to seven topologically different types of tiles: 48T-grc (2a), 32T-pau (12e), 30T-plg (16f), 24T-phi (24h), 20T-gsm (12d), 16T-opr (6b, 12e), and 16T-oto (24h, 48k). In the tiles, the positions occupied by extraframework cations A = Na+/Ca2+ and B = K+/Ba2+ have been determined. The characteristic arrangement of the Na+/Ca2+ cations only at the centers of the 8T rings has been revealed, and for them a new equivalent position in the 16T-opr (6b) tile has been determined. A common crystal-chemical formula of paulingite family zeolites has been obtained: (A,B0.5)154[T672O1344wH2O; for the two outermost members, this formula takes the form A154[T672O1344wH2O and B77[T672O1344wH2O. The composition of the alkaline Na,K-paulingite A154T672O1344·wH2O = Na82K72[Al154Si518O1344] ·wH2O corresponds to the model of a structure with a maximal (100%) and ordered filling of the A cation positions: in the 16T-oto (24h, 48k) tiles for K+ and in the 20T-gsm (12d), 30T-plg (16f), and 16T-opr (6b, 12e) tiles for Na+. Such a distribution and the overall number of Na and K atoms are in good agreement with the data for synthetic paulingite analogues the (Na87K72TEA15)[Al164Si508O1344wH2O aluminosilicate and (Na84.5K70.5TEA24.7)[Ga179.7Si492.3O1344wH2O gallosilicate.  相似文献   

15.
In the title compound, Na+·C14H11O2?, the di­phenyl­acetate ions have a conformation where the two phenyl rings and the carboxyl­ate group are oriented like the blades of a propeller, each ion having a well defined helicity. The crystal structure of the title compound is achiral, although non‐centrosymmetric (space group ); thus, ions with both (+) and (?) helicities are present in the crystal. Each Na+ ion is coordinated by four carboxyl­ate O atoms at distances in the range 2.207 (2)–2.467 (3) Å to form cubes of Na and O atoms which are linked via the carboxyl­ate C atoms into a columnar structure along the rotoinversion axis.  相似文献   

16.
Ion Exchange of Monovalent Cations in Synthetic Sodium Polysilicates with Layer Structure Cation-exchange equilibria of synthetic sodium polysilicates Ilerit (Na2O · 8.3SiO2 8.9 H2O) and Magadiite (Na2O · 13 SiO2 · 6.8 H2O) with H+, Li+ and K+ Ions were investigated with respect to their selectivity behaviour. The range of ion selectivity is: H+ > Na+ > Li+ > K+. Thermodynamic data ΔG, ΔH, and ΔS were determined by means of the integral thermodynamic equilibria constants Kth of the ion-exchange reactions.  相似文献   

17.
The title compound, tricaesium sodium iron(III) μ3‐oxido‐hexa‐μ2‐sulfato‐tris[aquairon(III)] pentahydrate, Cs2.91Na1.34Fe3+0.25[Fe3O(SO4)6(H2O)3]·5H2O, belongs to the family of Maus's salts, K5[Fe3O(SO4)6(H2O)3]·6H2O, which is based on the triaqua‐μ3‐oxido‐hexa‐μ‐sulfato‐triferrate(III) anion, [Fe3O(SO4)6(H2O)3]5−, with Fe in a characteristically distorted octahedral coordination environment, sharing a common corner via an oxide O atom. Cs in four different cation sites, Na in three different cation sites and five water molecules link the anions in three dimensions and set up a crystal structure in which those parts parallel to (001) and within 0.05 < z < 0.95 have a distinct trigonal pseudosymmetry, whereas the cation arrangement and bonding near z∼ 0 generate a clear‐cut noncentrosymmetric polar edifice with the monoclinic space group C2. The structure shows some cation disorder in the region near z ∼ , where one Na atom in octahedral coordination is partly substituted by Fe3+, and a Cs atom is substituted by small amounts of Na on a separate nearby site. One Na atom, located on a twofold axis at z = 0 and tetrahedrally coordinated by four sulfate O atoms of two [Fe3O(SO4)6(H2O)3]5− units, plays a key role in generating the noncentrosymmetric structure. Three of the seven different cation sites are on twofold axes (one Na+ site and two Cs+ sites), and all other atoms of the structure are in general positions.  相似文献   

18.
The room temperature reaction of Na4Sn2S6 · 5H2O with CoCl2 · 6H2O and 2-(aminomethyl)pyridine (2-AMP) or trans-1,2-diamino-cyclohexane (DACH) leads to crystallization of two compounds with the compositions [Co(2-(aminomethyl)pyridine)3]2 Sn2S6 · 10H2O ( 1 ) and [Co(trans-1,2-diaminocyclohexane)3]2Sn2S6 · 8H2O ( 2 ). In both compounds [Sn2S6]4– anions are present that are charge balanced each by two Co2+ centered complexes. Each of the two CoII cations are sixfold coordinated by six N atoms of three 2-AMP or DACH ligands within slightly distorted octahedra. In compound 1 , the two complexes are linked by one [Sn2S6]4– anion via strong N–H ··· S hydrogen bonds into centrosymmetric charge neutral trimeric units, that are further linked by weak C–H ··· S and N–H ··· S hydrogen bonds into chains that are directed along the a axis. These chains are further joined by N–H ··· O and O–H ··· O hydrogen bonds into a 3D network, with the H2O molecules forming chains along the b axis. The crystal structure of 2 is similar to that of 1 featuring trimeric units which are also linked into chains. Between the chains water molecules are embedded that link the chains into a 3D network. Upon heating 2 in a thermobalance the water and ligand molecules are removed in discrete steps, indicating that compounds with more condensed thiostannate networks will form.  相似文献   

19.
The crystal structures of two ibuprofen sodium dihydrates, racemic sodium (RS)‐2‐(4‐isobutylphenyl)propanoate dihydrate or (RS)‐NaIBDH, Na+·C13H17O2·2H2O, and enantiomeric sodium (S)‐2‐(4‐isobutylphenyl)propanoate dihydrate or (S)‐NaIBDH, Na+·C13H17O2·2H2O, have been determined in the space groups P and P1, respectively. The unit cells of the two triclinic structures have similar lattice parameters and cell volumes. The constituent ions have similar coordination environments, but differ slightly in their hydrogen‐bonding inter­actions. The dominance of the inter­actions between the O atoms and the Na+ cations explains the structural similarity of these two structures, despite the fact that one is heterochiral while the other is homochiral.  相似文献   

20.
The title complex, {[Ni(C2H8N2)3][Na(NCS)3(H2O)]}n, con­sists of discrete [Ni(en)3]2+ dications (en is ethyl­enedi­amine) and polymeric [(H2O)0.5Na(NCS)3(H2O)0.5]n2n? anions. The compound crystallizes in space group Pc1. The NiII atom lies on a threefold axis and has a distorted octahedral coordination geometry. The Na+ cation also lies on a site with imposed crystallographic threefold symmetry and is coordinated by the thio­cyanate N atoms (the thio­cyanates are in general posi­tions), by one water mol­ecule with crystallographically imposed 32 symmetry and by a second water mol­ecule with crystallographically imposed symmetry. The unique Na atom thus has trigonal–bipyramidal coordination. The O atoms of the water mol­ecules bridge the Na+ cations to form one‐dimensional polymeric chains in the crystal structure. The [Ni(en)3]2+ dications are distributed around and between the chains and are linked to them via N—H?S hydrogen bonds.  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