A ternary complex of aqua(18‐crown‐6)bis(o‐nitrophenolato)barium(II), the triaqua(18‐crown‐6)(o‐nitrophenolato)barium(II) cation and the o‐nitrophenolate anion

In the title compound [systematic name: tri­aqua(1,4,7,10,13,16‐hexaoxa­cyclo­octa­decane‐κ⁶O)(2‐nitro­phenolato‐κO)­barium(II)–aqua(1,4,7,10,13,16‐hexaoxa­cyclo­octa­decane‐κ⁶O)‐ bis(2‐nitro­phenolato‐κ²O,O′)­barium(II)–2‐nitro­phenolate (1/1/1)], [Ba(C₁₂H₂₄O₆)(C₆H₄NO₃)(H₂O)₃][Ba(C₁₂H₂₄O₆)(C₆H₄NO₃)₂(H₂O)](C₆H₄NO₃), the two Ba^II atoms encapsulated by the 18‐crown‐6 rings have different coordinations. Although both Ba^II atoms are coordinated to the six O atoms of the crowns, in the neutral moiety, the Ba^II atom is coordinated to one terminal O atom from a water mol­ecule, two phenolate O atoms and two nitro‐group O atoms, while in the cationic moiety, the Ba^II atom is coordinated to three terminal O atoms from water mol­ecules and one phenolate O atom. Both the crowns are eclipsed and translated along the b direction. In the asymmetric unit, the three components are interconnected by four O—H?O interactions. The packing is stabilized by two intermolecular C—H?O interactions and by one O—H?O interaction.     

A zirconium zwitterion containing a caged amine H atom

The crystallographically centrosymmetric zwitterion bis­[tris(3,5‐di­methyl‐2‐oxidobenzyl‐κO)­ammonium]­zirconium(IV) crystallizes as the chloro­form disolvate, [Zr(C₂₇H₃₁NO₃)₂]·2CHCl₃, with the two mol­ecules of chloro­form closely associated with two of the aromatic rings. The Zr atom has a distorted octahedral geometry with three phenoxy O atoms from each of the two ligands coordinated to it. Charge balance is maintained by protonation of each N atom, which then forms intramolecular hydrogen‐bonding interactions to all three adjacent O atoms.     

Poly[[μ‐aqua‐bis­(μ‐2,4‐dichloro­phen­oxy­acetato)barium(II)] monohydrate]

In the title coordination polymer, {[Ba(C₈H₅Cl₂O₃)₂(H₂O)]·H₂O}_n, each Ba^II atom is nine‐coordinated by six carboxyl­ate O atoms and one ether O atom from five symmetry‐related 2,4‐dichloro­phenoxy­acetate ligands, and by two O atoms from water mol­ecules, thus defining a distorted tricapped trigonal prism. The Ba^II ions are bridged by bidentate water mol­ecules and by tridentate and tetra­dentate 2,4‐dichloro­phenoxy­acetate groups, leading to a two‐dimensional layer structure. The crystal structure is further stabilized by hydrogen‐bonding inter­actions within each layer.     

Aqua­(di‐2‐pyridylamine)oxalato­copper(II) monohydrate

In the structure of the title complex, [Cu(C₂O₄)(C₁₀H₉N₃)(H₂O)]·H₂O, the Cu^II atom displays a square‐pyramidal geometry, being coordinated by two N atoms from the di‐2‐pyridylamine ligand, two O atoms from the oxalate group and one O atom of a water mol­ecule. The complex mol­ecules are linked to form a three‐dimensional supra­molecular array by hydrogen‐bonding inter­actions between coordinated/uncoordinated water mol­ecules and the uncoordinated oxalate O atoms of neighboring mol­ecules.     

Poly[tetra‐μ‐aqua‐hexa­aquadi‐μ3‐malon­ato‐dinitratodibarium(II)nickel(II)]

The title complex, [Ba₂Ni(C₃H₂O₄)₂(NO₃)₂(H₂O)₁₀]_n, has a two‐dimensional layer structure. The Ni atom lies on a crystallographic centre of symmetry in an octa­hedral NiO₆ environment, and is coordinated by four malonate O atoms in a planar arrangement and by two water mol­ecules in axial positions. The coordination of the unique Ba atom involves two nitrate O atoms, five water mol­ecules and three malonate O atoms.     

Di‐μ‐sulfido‐bis[diaqua(18‐crown‐6)­barium(II)]–saccharin (1/2)

The mol­ecule of the title compound {systematic name: di‐μ‐sulfido‐bis[di­aqua(1,4,7,10,13,16‐hexaoxa­cyclo­octade­cane‐κ⁶O)barium(II)] bis­[1,2‐benzisothiazol‐3(2H)‐one 1,1‐dioxide]}, [Ba₂S₂(C₁₂H₂₄O₆)₂(H₂O)₄](C₇H₅NO₃S)₂, lies on an inversion centre. The Ba^II atom encapsulated by the 18‐crown‐6 ring is coordinated by the six O atoms of the crown, two water O atoms and two bridging S atoms. The four‐membered ring composed of the Ba^II atoms and the bridging S atoms makes a dihedral angle of 67.1 (1)° with the crown‐ether ring. The aromatic ring system of the saccharin moiety is essentially planar. The packing is built up from layers of the mol­ecules and is stabilized by three intermolecular O—H?O hydrogen bonds.     

{[Ba2(C2O4)(H2O)6](NCS)2}n: a layered mixed‐anion barium oxalate

We present the first example of a compound containing Ba²⁺, C₂O₄²⁻, water and some additional halide or pseudo‐halide anions, viz. hexa‐μ₂‐aqua‐μ₆‐oxalato‐dibarium(II) diiso­thio­cyanate, {[Ba₂(C₂O₄)(H₂O)₆](NCS)₂}_n. The structure consists of positively charged planar covalent layers of Ba²⁺ cations, oxalate anions and water mol­ecules. The first coordination sphere of the Ba²⁺ cation contains six water mol­ecules and four O atoms from two planar oxalate anions. The oxalate anion lies on an inversion centre and is coordinated to six Ba²⁺ cations, each donor O atom being bonded to two cations. Pairs of water mol­ecules are coordinated by two Ba²⁺ cations. The layers are interspersed with non‐coordinated NCS⁻ anions.     

A fluoro­phenylboron‐functionalized zirconium silsesquioxane complex

Bis(η⁵‐cyclo­penta­dienyl)[rel‐(1R,5S,7R,14S)‐(1,3,5,7,9,11,14‐hepta­cyclo­pentyl‐7,14‐dioxidotri­cyclo­[7.3.3^1,9.1^5,11]­hepta­siloxan‐3‐yloxy)­bis­(penta­fluoro­phenyl)­borane(2−)]­zirconium, [Zr(C₅H₅)₂(C₄₇H₆₃BF₁₀O₁₂Si₇)], consists of [ZrCp₂] (Cp is cyclopentadienyl) and [(C₆F₅)₂B] moieties bound to a silsesquioxane core. The silsesquioxane binds to the Zr atom through two of its O atoms to form a distorted tetrahedron. The [(C₆F₅)₂B] moiety is bound to the silsesquioxane through an O atom, forming an Si—O—B bond angle of 168.4 (4)°. The steric and electronic effects of the Zr atom and the borate moieties force the silsesquioxane core to distort. These distortions can be seen by examination of the Si—O—Si bond angles.     

A lithium complex of pyridine‐2,6‐dicarboxylic acid

The crystal structure of catena‐poly­[[(6‐carboxy­pyridine‐2‐carb­oxyl­ato‐κ³O,N,O′)­lithium(I)]‐μ‐aqua‐κ²O:O], [Li(C₇H₄NO₄)­(H₂O)]_n, contains the Li⁺ ion coordinated to two O atoms and the N atom of the 6‐carboxy­pyridine‐2‐carboxyl­ate ligand, and to two water O atoms, forming a pentavalent coordination geometry. The molecule resides on a mirror plane which contains the Li and N atoms, the para‐CH unit, and the O atom of the coordinated water mol­ecule. The O atom of the water mol­ecule is coordinated to two Li atoms, forming an infinite polymeric chain.     

A one‐dimensional coordination polymer with metal–metal inter­actions: catena‐poly­[[tri­aqua­barium(II)]‐μ‐aqua‐κ2O:O‐di‐μ‐thio­salicyl­ato‐κ4O:O]

In the title compound, [Ba(C₇H₅O₂S)₂(H₂O)₄]_n, the Ba^II atom lies on a mirror plane and is nine‐coordinated by four bridging carboxylate O atoms of the thio­salicyl­ate ligands, two bridging water mol­ecules and three terminal water mol­ecules. There is an intramolecular S—H⋯O hydrogen bond between the S and O atoms in the thio­salicyl­ate ligand. A one‐dimensional coordination polymer is formed via weak metal–metal interactions along polymeric zigzag chains.     

(μ‐Oxalato‐O1,O2:O1′,O2′)bis[aqua(diethyl­enetri­amine)nickel(II)] bis(hexafluorophosphate) dihydrate

The title compound, [Ni₂(C₂O₄)(C₄H₁₃N₃)₂(H₂O)₂](PF₆)₂·‐2H₂O, contains a dinuclear oxalato‐bridged nickel(II) complex cation. The structure determination reveals the presence of a centrosymmetric binuclear complex where the oxalate ligand is coordinated in a bis­‐bidentate mode to the Ni atoms. The distorted octahedral environment of each Ni atom is completed by the three N atoms of the diethyl­enetri­amine ligand in a fac arrangement and by one O atom from a water mol­ecule. PF₆^? acts as counter‐anion. A two‐dimensional network of hydrogen bonds links the cations and anions and stabilizes the structure.     

A neodymium(III)–ammonium complex involving oxalate and carbonate ligands: (NH4)2[Nd2(C2O4)3(CO3)(H2O)]·H2O

The title compound, di­ammonium aqua‐μ‐carbonato‐tri‐μ‐­oxalato‐dineodymium(III) hydrate, (NH₄)₂[Nd₂(CO₃)(C₂O₄)₃(H₂O)]·H₂O, involving the two ligands oxalate and carbonate, has been prepared hydro­thermally as single crystals. The Nd atoms form a tetranuclear unit across the inversion centre at (,,). Starting from this tetranuclear unit, the oxalate ligands serve to develop a three‐dimensional network. The carbonate group acts as a bis‐chelating ligand to two Nd atoms, and is monodentate to a third Nd atom. The oxalate groups are all bis‐chelating. The two independent Nd atoms are ninefold coordinated and the coordination polyhedron of these atoms is a distorted monocapped antiprism.     

Bis(2,2′‐bi­pyridine‐κ2N,N′)(oxalato‐κ2O,O′)­cobalt(II) pentahydrate

The synthesis and crystal structure of the mononuclear title compound, [Co(C₂O₄)(C₁₀H₈N₂)₂]·5H₂O, is reported. The Co atom is six‐coordinated by two O atoms of a bidentate oxalate group and by four N atoms of two bi­pyridine ligands. The neutral [Co(C₂O₄)(C₁₀H₈N₂)₂] entities are connected by π–π stacking interactions of the aromatic systems into a two‐dimensional layer, interconnected through a ladder‐like hydrogen‐bonding pattern of solvate water mol­ecules.     

(2‐Methyl­quinolin‐8‐olato)­iron(III) and ‐copper(II) complexes

The crystal structures of tris(2‐methyl­quinolin‐8‐olato‐N,O)­iron(III), [Fe­(C₁₀­H₈­NO)₃], (I), and aqua­bis(2‐methyl­quinolin‐8‐olato‐N,O)­copper(II), [Cu­(C₁₀­H₈NO)₂­(H₂O)], (II), have been determined. Compound (I) has a distorted octahedral configuration, in which the central Fe atom is coordinated by three N atoms and three O atoms from three 2‐methylquinolin‐8‐olate ligands. The three Fe—O bond distances are in the range 1.934 (2)–1.947 (2) Å, while the three Fe—N bond distances range from 2.204 (2) to 2.405 (2) Å. In compound (II), the central Cu^II atom and H₂O group lie on the crystallographic twofold axis and the coordination geometry of the Cu^II atom is close to trigonal bipyramidal, with the three O atoms in the basal plane and the two N atoms in apical positions. The Cu—N bond length is 2.018 (5) Å. The Cu—O bond length in the basal positions is 1.991 (4) Å, while the Cu—O bond length in the apical position is 2.273 (6) Å. There is an intermolecular OW—H?O hydrogen bond which links the mol­ecules into a linear chain along the b axis.     

catena‐Poly[[aqua­barium(II)]‐μ‐aqua‐bis­(μ‐2′‐carboxy­biphenyl‐2‐carboxyl­ato)]

In the title compound, [Ba{HOOC(C₆H₄)₂CO₂}₂(H₂O)₂] or [Ba(C₁₄H₉O₄)₂(H₂O)₂], the Ba atoms are coordinated by nine O atoms, six from two 2′‐carboxy­biphenyl‐2‐carboxyl­ate (Hbpdc⁻) ligands and three from three coordinated water mol­ecules, resulting in the formation of face‐sharing distorted monocapped square anti­prisms. The Hbpdc⁻ ligands bridge the Ba atoms to form a one‐dimensional helical polymer, with a Ba⋯Ba distance across the chain of 4.1386 (17) Å. Adjacent chains are parallel to each other. The two independent ligands are tetra­dentate and have the same coordination mode, exhibiting μ‐oxo bridges and η⁸‐chelation. The crystal structure is further stabilized by hydrogen bonds within each chain.     

RbCrIII(C2O4)2·2H2O,Cs2Mg(C2O4)2·4H2O and Rb2CuII(C2O4)2·2H2O: three new complex oxalate hydrates

Rubidium chromium(III) dioxalate dihydrate [di­aqua­bis(μ‐oxalato)­chromium(III)­rubidium(I)], [RbCr(C₂O₄)₂(H₂O)₂], (I), and dicaesium magnesium dioxalate tetrahydrate [tetra­aqua­bis(μ‐oxalato)­magnesium(II)­dicaesium(I)], [Cs₂Mg(C₂­O₄)₂(H₂O)₄], (II), have layered structures which are new among double‐metal oxalates. In (I), the Rb and Cr atoms lie on sites with imposed 2/m symmetry and the unique water molecule lies on a mirror plane; in (II), the Mg atom lies on a twofold axis. The two non‐equivalent Cr and Mg atoms both show octahedral coordination, with a mean Cr—O distance of 1.966 Å and a mean Mg—O distance of 2.066 Å. Dirubid­ium copper(II) dioxalate dihydrate [di­aqua­bis(μ‐oxalato)­copper(II)­dirubidium(I)], [Rb₂Cu(C₂O₄)₂(H₂O)₂], (III), is also layered and is isotypic with the previously described K₂‐ and (NH₄)₂Cu^II(C₂O₄)₂·2H₂O compounds. The two non‐equivalent Cu atoms lie on inversion centres and are both (4+2)‐coordinated. Hydro­gen bonds are medium‐strong to weak in the three compounds. The oxalate groups are slightly non‐planar only in the Cs–Mg compound, (II), and are more distinctly non‐planar in the K–Cu compound, (III).     

trans‐Di­aqua­bis(5‐carboxy‐1H‐imidazole‐4‐carboxyl­ato‐κ2N3,O4)­cobalt(II) 4,4′‐bi­pyridine solvate

In the title compound, [Co(C₅H₃N₂O₄)₂(H₂O)₂]·C₁₀H₈N₂, the Co atom is trans‐coordinated by two pairs of N and O atoms from two monoanionic 4,5‐di­carboxy­imidazole ligands, and by two O atoms from two coordinated water mol­ecules, in a distorted octahedral geometry. The 4,4′‐bi­pyridine solvent molecule is not involved in coordination but is linked by an N—H⋯N hydrogen bond to the neutral [Co(C₅H₃N₂O₄)₂(H₂O)₂] mol­ecule. Both mol­ecules are located on inversion centers. The crystal packing is stabilized by N—H⋯N and O—H⋯O hydrogen bonds, which produce a three‐dimensional hydrogen‐bonded network. Offset π–π stacking interactions between the pyridine rings of adjacent 4,4′‐bi­pyridine molecules were observed, with a face‐to‐face distance of 3.345 (1) Å.     

Triaqua(oxalato‐O,O′)oxovanadium(IV) dihydrate

In the structure of the title compound, [VO(C₂O₄)(H₂O)₃]·2H₂O, the V atom of the oxovanadium(IV) cation is coordinated to one bidentate oxalate anion and three water mol­ecules, resulting in a neutral complex. Two more water mol­ecules are not coordinated to the V atoms but are involved in the hydrogen‐bonding network, which consists of ten different hydrogen bonds.     

trans‐Diaquabis(1H‐imidazole‐4,5‐di­carboxyl­ate‐κ2N3,O4)­manganese(II)

In the title compound, [Mn(C₅H₃N₂O₄)₂(H₂O)₂], the Mn^II atom lies on an inversion centre, is trans‐coordinated by two N,O‐bidentate 1H‐imidazole‐4,5‐di­carboxyl­ate monoanionic ligands [Mn—O = 2.202 (3) Å and Mn—N = 2.201 (4) Å] and two water mol­ecules [Mn—O = 2.197 (4) Å], and exhibits a distorted octahedral geometry, with adjacent cis angles of 76.45 (13), 86.09 (13) and 89.20 (13)°. The complete solid‐state structure can be described as a three‐dimensional supramol­ecular framework, stabilized by extensive hydrogen‐bonding interactions involving the coordinated water mol­ecules, the carboxy O atoms and the protonated imidazole N atoms of the imidazole‐4,5‐di­carboxyl­ate ligands.     

(Acetonitrile‐κN){2‐[bis­(2‐pyridylethyl)­amino]ethanol‐κ4N,N′,N′′,O}zinc(II) bis­(perchlorate) monohydrate

In the title compound, [Zn(C₂H₃N)(C₁₆H₂₁N₃O)](ClO₄)₂·H₂O, the Zn^II ion is coordinated by two pyridyl N atoms, one amine N atom, and an ethanol O atom from the N,N′,N′′,O‐tetra­dentate 2‐[bis­(2‐pyridylethyl)amino]­ethanol donor ligand. The fifth coordination site is filled by an acetonitrile N atom, and there is one solvent water mol­ecule in the asymmetric unit. The 2+ charge of the cationic portion of the complex is balanced by two perchlorate counter‐anions.