Halogen‐bonded adduct of 1,2‐dibromo‐1,1,2,2‐tetrafluoroethane and 1,4‐diazabicyclo[2.2.2]octane

Halogen bonding is an intermolecular interaction capable of being used to direct extended structures. Typical halogen‐bonding systems involve a noncovalent interaction between a Lewis base, such as an amine, as an acceptor and a halogen atom of a halofluorocarbon as a donor. Vapour‐phase diffusion of 1,4‐diazabicyclo[2.2.2]octane (DABCO) with 1,2‐dibromotetrafluoroethane results in crystals of the 1:1 adduct, C₂Br₂F₄·C₆H₁₂N₂, which crystallizes as an infinite one‐dimensional polymeric structure linked by intermolecular N...Br halogen bonds [2.829 (3) Å], which are 0.57 Å shorter than the sum of the van der Waals radii.     

Structural links between zeolite-type and clathrate hydrate-type materials: Synthesis and crystal Structure of [N(CH3)4]6[AlxSi8−xO18−x(OH)2+x] · 44H2O (x = 3–4)

A novel tetramethylammonium aluminosilicate hydrate with the approximate composition [NMe₄]₆[Al_xSi_8?xO_18?x(OH)_2+x] · 44H₂O (x = 3–4) has been identified by powder X-ray diffraction as a component in a polyphasic solid mixture which crystallized at room temperature from an aqueous NMe₄OH? Al₂O₃? SiO₂ solution. Large crystals of the novel hydrate phase could be mechanically selected from that mixture. The crystal structure has been determined from 1 196 unique MoKα diffraction data measured at 180 K: Tetragonal crystal system, cell constants a = 16.181(4) and c = 17.450(4) Å, space group P4/mnc with Z = 2 formula units per unit cell, R = 0.072. The host-guest compound is of polyhedral clathrate type with a mixed three-dimensional, (mainly) four-connected network composed of oligomeric aluminosilicate anions [Al_xSi_8?xO_18?x(OH)_2+x]^6? and H₂O molecules linked via hydrogen bonds O? H …? O. The aluminosilicate anions possess a cube-shaped (double four-ring) structure. Orientationally disordered cationic guest species NMe₄⁺ are enclosed in the large [4⁶6⁸] and [4¹5¹⁰6⁷] polyhedral voids of the host framework; the small [4⁶] cages (i.e. the double four-ring anions) and [4³5⁶] cages are empty. The hydrate is a further member in a recently discovered series of clathrates with mixed tetrahedral networks, which provides a structure-chemical link between zeolite- and clathrate hydrate-type host-guest compounds.     

Water-rich molybdotellurates: Preparation and crystal structure of Li6[TeMo6O24] · 18 H2O and Li6[TeMo6O24] · Te(OH)6 · 18 H2O

Li₆[TeMo₆O₂₄] · 18 H₂O is triclinic (space group P1 , a = 1 041.7(1), b = 1 058.6(1), c = 1 070.8(1) pm, α = 61.08(1), β = 60.44(1), γ = 73.95(1)°). Single crystal X-ray structure analysis (Z = 1, 295 K, 317 parameters, 3 973 reflections, R_g = 0.0250) revealed an infinite branched chain of edge-sharing Li coordination polyhedra to be the prominent structural feature. One of the four crystallographically independent Li⁺ is coordinated octahedrally. The coordination polyhedra of the remaining Li⁺ are distorted trigonal bipyramids. Only three unique oxygen atoms (O(9), O(10), O(12)) of the centrosymmetric [TeMo₆O₂₄]^6? anion are bound to Li⁺. The further positions in the coordination spheres of the Li⁺ are occupied by water molecules. Intermolecular hydrogen bonds involve mainly oxygen atoms of the [TeMo₆O₂₄]^6? anion as nearly equivalent proton acceptors without regard to their different bonding modes to Te and Mo, respectively. Li₆[TeMo₆O₂₄] · Te(OH)₆ · 18 H₂O crystallizes monoclinically in space group P2₁/n with Z = 4, a = 994.1(3), b = 2 344.8(10), c = 1 764.9(4) pm, and β = 91.36(4)°. Single crystal structure analysis with least squares refinement of 627 parameters (5 900 reflections, 295 K) converged to R_g = 0.0324. There are six unique Li⁺ cations. The coordination polyhedra of Li(1), Li(2), Li(3), and Li(4) are linked by common edges to yield an eight membered centrosymmetric strand. The coordination polyhedra of the remaining two Li⁺ sites (Li(5), Li(6)) are connected to a dimeric unit via a common corner. All oxygen atoms of the Te(OH)₆ molecule are involved in the coordination of Li⁺. However, only three oxygen atoms (O(13), O(18), O(23)) of the [TeMo₆O₂₄]^6? anion which lacks crystallographic symmetry are involved in the coordination of Li⁺. The oxygen atoms of the anion act as proton acceptors in hydrogen bonds of predominantly medium strength. Te(OH)₆ molecules and [TeMo₆O₂₄]^6? anions connected by strong hydrogen bonds form an infinite chain.     

On the proton-acceptor properties of [TeMo6O24]6− in Na4(NH4)2[TeMo6O24] · 16H2O

Colourless triclinic single crystals of Na₄(NH₄)₂[TeMo₆O₂₄] · 16H₂O were grown in aqueous solution (space group P1 , a = 1 075.3(1), b = 1 074.2(1), c = 1 089.8(1) pm, = 96.259(9), β = 118.556(7), γ = 113.355(8)°, Z = 1, 295 K, 311 parameters, 3 689 reflections, R_g = 0.0197). There are two crystallographically independent Na⁺ cations. Na(1) is coordinated octahedrally by four water molecules and two oxygen atoms of the centrosymmetric [TeMo₆O₂₄]^6? anion. Na(2) is bound to five water molecules in a considerably distorted trigonally bipyramidal fashion. These bipyramids are linked with NH₄⁺ by hydrogen bonds to yield centrosymmetric cluster cations consisting of two NH₄⁺ and two Na(H₂O)₅⁺ each. Hydrogen bonds envolving all except one (O(10)) of the oxygen atoms of the [TeMo₆O₂₄]^6? anion as almost equivalent proton acceptors regardless of their bonding mode to Te and Mo, respectively, establish further connections to NH₄⁺ and the water of crystallization.     

(8RS)‐4‐Amino‐6‐(4‐chlorophenyl)‐8‐(2,4‐dichlorothiazol‐5‐yl)‐8,9‐dihydro‐7H‐pyrimido[4,5‐b][1,4]diazepine N,N‐dimethylformamide monosolvate: sheets built from N—H...N and C—H...O hydrogen bonds

In the title compound, C₁₆H₁₁Cl₃N₆S·C₃H₇NO, the seven‐membered ring adopts a conformation which is close to the twist‐boat form. The molecular components are linked into sheets by a combination of two N—H...N hydrogen bonds and two C—H...O hydrogen bonds. Comparisons are made with other aminopyrimidine derivatives.     

The effect of coordinated water on the connectivity of uranium(IV) sulfate x‐hydrate: [U(SO4)2(H2O)5]·H2O and [U(SO4)2(H2O)6]·2H2O,and a comparison with other known structures

Two new solid‐state uranium(IV) sulfate x‐hydrate complexes (where x is the total number of coordinated plus solvent waters), namely catena‐poly[[pentaaquauranium(IV)]‐di‐μ‐sulfato‐κ⁴O:O′] monohydrate], {[U(SO₄)₂(H₂O)₅]·H₂O}_n, and hexaaquabis(sulfato‐κ²O,O′)uranium(IV) dihydrate, [U(SO₄)₂(H₂O)₆]·2H₂O, have been synthesized, structurally characterized by single‐crystal X‐ray diffraction and analyzed by vibrational (IR and Raman) spectroscopy. By comparing these structures with those of four other known uranium(IV) sulfate x‐hydrates, the effect of additional coordinated water molecules on their structures has been elucidated. As the number of coordinated water molecules increases, the sulfate bonds are displaced, thus changing the binding mode of the sulfate ligands to the uranium centre. As a result, uranium(IV) sulfate x‐hydrate changes from being fully crosslinked in three dimensions in the anhydrous compound, through sheet and chain linking in the tetra‐ and hexahydrates, to fully unlinked molecules in the octa‐ and nonahydrates. It can be concluded that coordinated waters play an important role in determining the structure and connectivity of U^IV sulfate complexes.     

Bis‐Bromine‐1,4‐Diazabicyclo[2.2.2]Octane (Br2‐DABCO) as an Efficient Promoter for One‐Pot Conversion of N‐Arylglycines to N‐Arylsydnones in the Presence of NaNO2/Ac2O Under Neutral Conditions

Bis‐Bromin‐1,4‐diazabicyclo[2.2.2]octane (Br₂‐DABCO)‐promoted one‐pot conversion of various N‐arylglycines to sydnones using a combination of NaNO₂ and Ac₂O has been achieved efficiently through N‐nitrosation followed by cyclization in high yields (90‐96%) under mild and neutral conditions.     

Die Kristallstruktur des Natriumoxohydroxoaluminathydrates Na2[Al2O3(OH)2] · 1,5 H2O

The Crystal Structure of the Sodium Oxohydroxoaluminate Hydrate Na₂[Al₂O₃(OH)₂] · 1.5 H₂O The crystal structure of the sodium oxohydroxoaluminate hydrate Na₂[Al₂O₃(OH)₂] ·s 1.5 H₂O (up to now described as Na₂O · Al₂O₃ · 2.5 H₂O and Na₂O · Al₂O₃ · 3 H₂O, respectively) was solved. The X-ray single crystal diffraction analysis (tetragonal, space group P-42₁m, a = 10.522(1) Å, c = 5.330(1) Å, Z = 4) results in a polymeric layered structure, consisting of AlO_3/2(OH) tetrahedral groups. Between these layers the Na⁺ ions are situated, which form tetrameric groups of face-linked NaO₆ octahedra. The involved O^2? ions are due to Al? O? Al bridges, Al? OH groups and water of crystallization. ²⁷Al and ²³Na MAS NMR investigations confirm the crystal structure analysis. The relations between the crystallization behaviour of the compound and the constitution of the aluminate anions in the corresponding sodium aluminate solution and in the solid, respectively, are discussed.     

Crystal structures of sodium magnesium selenate decahydrate,Na2Mg(SeO4)2·10H2O,a new selenate salt,and sodium magnesium selenate dihydrate,Na2Mg(SeO4)2·2H2O

Metal selenates crystallize in many instances in isomorphic structures of the corresponding sulfates. Sodium magnesium selenate decahydrate, Na₂Mg(SeO₄)₂·10H₂O, and sodium magnesium selenate dihydrate, Na₂Mg(SeO₄)₂·2H₂O, were synthesized by preparing solutions of Na₂SeO₄ and MgSeO₄·6H₂O with different molar ratios. The structures contain different Mg octahedra, i.e. [Mg(H₂O)₆] octahedra in the decahydrate and [MgO₄(H₂O)₂] octahedra in the dihydrate. The sodium polyhedra are also different, i.e. [NaO₂(H₂O)₄] in the decahydrate and [NaO₆(H₂O)] in the dihydrate. The selenate tetrahedra are connected with the chains of Na polyhedra in the two structures. O—H…O hydrogen bonding is observed in both structures between the coordinating water molecules and selenate O atoms.     

Cs6[TeMo6O24] · 2 Te(OH)6 · 4 H2O ? eine Tellursäure-reiche Einschlußverbindung

Cs₆[TeMo₆O₂₄] · 2 Te(OH)₆ · 4 H₂O – A Telluric Acid-rich Inclusion Compound Single crystals of Cs₆[TeMo₆O₂₄] · 2 Te(OH)₆ · 4 H₂O have been grown from aqueous solution. It crystallizes triclinically in space group P1 with Z = 1, a = 1 086.6(1), b = 1 095.6(1), c = 1 105.5(1) pm, α = 118.83(1), β = 106.22(1) and γ = 100.00(1)°. X-ray structure determination (5 755 reflections, 251 parameters, R_g = 0.0355) revealed an infinite chain consisting of hydrogen bonded (OH …? O 259.4(5) – 267.4(6) pm) Te(OH)₆ molecules and [TeMo₆O₂₄]^6? anions to be the Prominent structural feature. Further hydrogen bonds between neighbouring Te(OH)₆ molecules connect these chains to yield a two-dimensionally infinite arrangement.     

Preparation and crystal structure of Guanidinium Cyclododecaphosphate Telluric Acid Hydrate: [C(NH2)3]12P12O36 · 12 Te(OH)6 · 24H2O

The title compound ist the first example of an adduct between telluric acid and the twenty four membered ring anion of a cyclododecaphosphate. [C(NH₂)₃]₁₂P₁₂O₃₆ · 12 Te(OH)₆ · 24 H₂O crystallizes trigonal (rhomboedral: R3) with Z = 3 and the unit-cell dimensions a = 15.854(9), c = 51.26(2) Å in the hexagonal setting. The crystal structure was solved by direct methods and refined to a final R value of 0.031. It is characterized by a succession of three different typs of alternating layers perpendicular to the c direction. This layers are connected only by hydrogen bonds. The individual layers are built up of A: P₁₂O₃₆ anions, guanidinium cations and water of crystallisation, B: hexagonal arranged Te(OH)₆ groups and guanidinium cations and C: water of crystallization.     

Preparation and Crystal Structure of Guanidinium Cyclododecaphosphate Hexahydrate: [C(NH2)3]12P12O36 · 6H2O

The title compound was prepared by ion exchange from the potassium salt, K₁₂P₁₂O₃₆ · 19/2H₂O. It represents a second new structural type of [P₁₂O₃₆]^12? ring anions. This sparingly water soluble salt is hexagonal, space group P6₃, with Z = 2 and the cell dimensions: a = 15.904(7), c = 16.67(2) Å. The crystal structure was solved by direct methods and refined to a final R value of 0.050. The ring anion is located around the threefold axis and hence has a threefold symmetry. The stacking of the rings creates large channels, parallel to the c direction, in which the guanidinium groups and the water molecules are located. Three of the six independent guanidinium groups are located on the threefold axes. The cohesion of the structure is performed by the numerous H-bonds generated by the organic cations and the water molecules.     

Variation of 2 D Hydrogen Bond Topology in Diaqua-tetrafluoromanganates(III): 2-picoH[MnF4(H2O)2], TMEDAH2[MnF4(H2O)2]2, and TMBDAH2[MnF4(H2O)2]2

The crystal structures of three new diaqua-tetrafluoro-manganate(III) compounds with different organic N-cations have been determined: 2-picoH[MnF₄(H₂O)₂] 1 (2-pico = 2-methyl-pyridine), space group P2₁/c, a = 9.439, b = 13.662, c = 7.641 Å, β = 91.31°; R = 0.059; TMEDAH₂[MnF₄(H₂O)₂]₂ 2 (TMEDA = N,N,N′,N′-tetramethyl ethane diamine), space group P2₁/c, a = 5.421, b = 15.970, c = 9.677 Å, β = 96.37°, R = 0.031, and TMBDAH₂[MnF₄(H₂O)₂]₂ 3 (TMBDA = N,N,N′,N′-tetramethyl-1,4-butane-diamine), space group P2₁/n, a = 12.631, b = 5.577, c = 12.976 Å, β = 98.10°, R = 0.040. All three compounds show 2 D H-bonding networks of [MnF₄(H₂O)₂]^– anions separated by the organic cations. However, the topology of the anionic H-bonding nets is different for each compound. The anions are strongly elongated by the Jahn-Teller effect and are arranged in a ferrodistortive way in compounds 1 and 2 , whereas in compound 3 the arrangement is described as in a herringbone-like antiferrodistortive variant.     

One‐dimensional decavanadate chains in the crystal structure of Rb4[Na(H2O)6][HV10O28]·4H2O

New decavanadate minerals, the products of the leaching or metasomatic processes, are possible in nature via Na/Rb removal/inclusion reactions. As part of our search for novel vanadate phases with varying functionalities, a new phase, tetrarubidium hexaaquasodium hydrogen decavanadate tetrahydrate, Rb₄[Na(H₂O)₆][HV₁₀O₂₈]·4H₂O, has been synthesized by the hydrothermal technique at 553 K. Ten shared edges of V‐centred octahedra form monoprotonated decavanadate cages, which are joined together via hydrogen bonds into one‐dimensional chains parallel to the [101] direction. Within these chains, H atoms are sandwiched between neighbouring polyanions. Na and Rb atoms and H₂O molecules occupy interstices flanked by the anionic chains providing additional crosslinking in the structure. This compound is the second decavanadate with P2/n symmetry. Structural relationships among protonated and deprotonated decavanadates with inorganic cations, including minerals of the pascoite group, are discussed.     

The isotypic hydrogen phosphate and arsenate dihydrates M2HXO4·2H2O (M = Rb,Cs; X = P,As)

The four isotypic alkaline metal monohydrogen arsenate(V) and phosphate(V) dihydrates M₂HXO₄·2H₂O (M = Rb, Cs; X = P, As) [namely dicaesium monohydrogen arsenate(V) dihydrate, Cs₂HAsO₄·2H₂O, dicaesium monohydrogen phosphate(V) dihydrate, Cs₂HPO₄·2H₂O, dirubidium monohydrogen arsenate(V) dihydrate, Rb₂HAsO₄·2H₂O, and dirubidium monohydrogen phosphate(V) dihydrate, Rb₂HPO₄·2H₂O] were synthesized by reaction of an aqueous H₃XO₄ solution with one equivalent of aqueous M₂CO₃. Their crystal structures are made up of undulating chains extending along [001] of tetrahedral [XO₃(OH)]⁻ anions connected via strong O—H...O hydrogen bonds. These chains are in turn connected into a three‐dimensional network via medium‐strength hydrogen bonding involving the water molecules. Two crystallographically different M⁺ cations are located in channels running along [001] or in the free space of the [XO₃(OH)]⁻ chains, respectively. They are coordinated by eight and twelve O atoms forming irregular polyhedra. The structures possess pseudosymmetry. Due to the ordering of the protons in the [XO₃(OH)]⁻ chains in the actual structures, the symmetry is reduced from C2/c to P2₁/c. Nevertheless, the deviation from C2/c symmetry is minute.     

Salze von Halogenophosphorsäuren. XIX. Über die Darstellung von Kupfer(II)-monofluorophosphat-Solvaten und die Kristallstruktur von Aquamonofluorophosphatokupfer(II)-1,4-Dioxan 2/1, 2[Cu(H2O)PO3F] · C4H8O2

Salts of Halogenophosphoric Acids. XIX. Preparation of Copper(II) Monofluorophosphate Solvates and the Crystal Structure of Aquamonofluorophosphatocopper(II)-1,4-Dioxane 2/1, 2[Cu(H₂O)PO₃F] · C₄H₈O₂ The mixed solvate Aquamonofluorophosphatocopper(II)-1,4-Dioxane 2/1 1 was obtained by the reaction of aqueous solutions of NH₄HPO₃F and acidified (NH₄)₂PO₃F, respectively, using 1,4-dioxane as precipitating agent. 1 crystallizes in the monoclinic space group C2/m with a = 2130.9(2), b = 655.45(6), c = 447.30(4) pm, b? = 96.207(7)° and Z = 2. Copper(II) monofluorophosphate-methanol 1/1, CuPO₃F · CH₃OH 2 was obtained by the reaction of copper(II) salts with alkaline or ammoniummonofluorophosphates in methanol. 1 and 2 react in the presence of water vapor to copper(II) monofluoro phosphate dihydrate, CuPO₃F · 2H₂O 3 , which reacts reversibly with dioxan or CH₃OH under formation of 1 and 2 , respectively.     

Synthesis and Crystal Structure of the Binuclear Complex [Pr2(C10H8N2O4)2(C10H9N2O4)2(H2O)4]·3H2O·C6H6

The binuclear praseodymium(III) complex with N‐(1‐carboxyethylidene)‐salicylhydrazide (C₁₀H₁₀N₂O₄, H₂L) was prepared in H₂O‐C₂H₅OH mixed solution, and the crystal structure of [Pr₂L₂(HL)₂(H₂O)₄]·3H₂O·C₆H₆ 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 Pr³⁺ 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.     

Darstellung und Einkristall-Strukturanalyse von Hexachloro-μ-dichloro-bis[N-(trimethylsilyl)imidazol]dititan-Chloroform (1/2) [Ti2Cl8(C6H12N2Si)2] · 2 CHCl3

Synthesis and Crystal Structure Determination of Hexachloro-μ-dichloro-bis[N-(trimethylsilyl)imidazol]dititanium Chloroform (1/2) Hexachloro-μ-dichloro-bis[N-(trimethylsilyl)-imidazol]dititanium chloroform (1/2) 1 has been prepared by the reaction of titanium tetrachloride with N-trimethylsilylimidazole (NTMSI) in chloroform solution as orange crystals. The structure consists of two distorted TiCl₅N octahedrons, which are connected by two chlorine atoms via common edges to a centrosymmetric dimer [Ti₂Cl₈(NTMSI)₂] · 2 CHCl₃. The N-trimethylsilylimidazole ligands each are located at one axial position of each octahedron, whereas the equatorial positions are occupied by the chloro ligands. The results presented are discussed assuming a gradual formation of an 1 : 1 and 1 : 2 adduct.     

[Gd(C10H9N2O4)(C10H8N2O4)(H2O)3]2·phen·4H2O的晶体结构和生物活性

在水乙醇混合溶剂中，首次得到了2-羰基丙酸水杨酰腙、1，10-菲啰啉与硝酸钆形成的配合物[Gd(C₁₀H₉N₂O₄)(C₁₀H₈N₂O₄)(H₂O)₃]₂·phen·4H₂O，并测试了其单晶结构。该配合物属三斜晶系，空间群为P-1。每个配合物分子中有两个九配位的钆的结构单元，每个钆离子与两个三齿配体2-羰基丙酸水杨酰腙（分别以负一价和负二价形式）和三个水分子配位。每个钆单元在空间呈扭曲的单帽四方反棱柱。同时还有一个游离的1，10-菲啰啉存在于晶格中，通过氢键与配位水作用。生物活性试验表明该配合物对三种病原菌有一定的抑菌活性。     

CB‐TE2A+·Cl−·3H2O: a short intermolecular hydrogen bond between zwitterionic bicyclo[6.6.2]tetraamine macrocycles

1,4,8,11‐Tetraazabicyclo[6.6.2]hexadecane‐4,11‐diacetic acid (CB‐TE2A) is of much interest in nuclear medicine for its ability to form copper complexes that are kinetically inert, which is beneficial in vivo to minimize the loss of radioactive copper. The structural chemistry of the hydrated HCl salt of CB‐TE2A, namely 11‐carboxymethyl‐1,8‐tetraaza‐4,11‐diazoniabicyclo[6.6.2]hexadecane‐4‐acetate chloride trihydrate, C₁₆H₃₁N₄O₄⁺·Cl⁻·3H₂O, is described. The compound crystallized as a positively charged zwitterion with a chloride counter‐ion. Two of the amine groups in the macrocyclic ring are protonated. Formally, a single negative charge is shared between two of the carboxylic acid groups, while one chloride ion balances the charge. Two intramolecular hydrogen bonds are observed between adjacent pairs of N atoms of the macrocycle. Two intramolecular hydrogen bonds are also observed between the protonated amine groups and the pendant carboxylate groups. A short intermolecular hydrogen bond is observed between two partially negatively charged O atoms on adjacent macrocycles. The result is a one‐dimensional polymeric zigzag chain that propagates parallel to the crystallographic a direction. A second intermolecular interaction is a hydrogen‐bonding network in the crystallographic b direction. The carbonyl group of one macrocycle is connected through the three water molecules of hydration to the carbonyl group of another macrocycle.