Bis(2‐amino‐1H‐benzimidazol‐3‐ium) tetrakis(μ‐but‐2‐enoato)‐κ4O:O′;κ3O,O′:O;κ3O:O,O′‐bis[bis(but‐2‐enoato‐κ2O,O′)holmium(III)]

The title ionic compound, (C₇H₈N₃)₂[Ho₂(C₄H₅O₂)₈], is constructed from two almost identical independent centrosymmetric anionic dimers balanced by two independent 2‐amino‐1H‐benzimidazol‐3‐ium (Habim⁺) cations. The asymmetric part of each dimer is made up of one Ho^III cation and four crotonate (crot or but‐2‐enoate) anions, two of them acting in a simple η²‐chelating mode and the remaining two acting in two different μ₂:η² fashions, viz. purely bridging and bridging–chelating. Symmetry‐related Ho^III cations are linked by two Ho—O—Ho and two Ho—O—C—O—Ho bridges which lead to rather short intracationic Ho...Ho distances [3.8418 (3) and 3.8246 (3) Å]. In addition to the obvious Coulombic interactions linking the cations and anions, the isolated [Ho₂(crot)₈]²⁻ and Habim⁺ ions are linked by a number of N—H...O hydrogen bonds, in which all N—H groups of the cation are involved as donors and all (simple chelating) crot O atoms are involved as acceptors. These interactions result in compact two‐dimensional structures parallel to (110), which are linked to each other by weaker π–π contacts between Habim⁺ benzene groups.     

Two isomorphous transition metal complexes containing a protonated diaminopurine ligand: diaquabis(2,6‐diamino‐7H‐purin‐1‐ium‐κN9)bis(homophthalato‐κO)nickel(II) tetrahydrate and the cobalt(II) analogue

The two isomorphous title compounds, [M(C₅H₇N₆)₂(C₉H₆O₄)₂(H₂O)₂]·4H₂O or M²⁺(Hdap⁺)₂(hpt²⁻)₂(H₂O)₂·4H₂O {where dap is 2,6‐diaminopurine, H₂hpt is homophthalic acid [2‐(2‐carboxyphenyl)acetic acid] and M is Ni^II or Co^II}, consist of neutral M²⁺(Hdap⁺)₂(hpt²⁻)₂(H₂O)₂ monomers, where the M^II cation lies on an inversion centre and its MN₂O₄ octahedral environment is defined by one N atom (from Hdap⁺), two O atoms (from one hpt²⁻ dianion and one water molecule) and their inversion images. The structures are unusual in that the Hdap⁺ cation occurs in an uncommon protonated state (as 2,6‐diamino‐7H‐purin‐1‐ium) and both ligands bind in an unprecedented monodentate fashion. The existence of a large number of donors and acceptors for hydrogen bonding, together with π–π interactions, leads to a rather complex three‐dimensional structure.     

catena‐Poly[[[diaqua[3‐(pyridin‐4‐yl)benzoato‐κ2O,O′]terbium(III)]‐bis[μ‐3‐(pyridin‐4‐yl)benzoato‐κ2O:O′]] monohydrate]

In the title compound, {[Tb(C₁₂H₈NO₂)₃(H₂O)₂]·H₂O}_n, the Tb^III cation is in an eight‐coordinate environment, ligated by six carboxylate O atoms from five 3‐(pyridin‐4‐yl)benzoate (L) ligands and by two O atoms from water molecules. The cations are bridged by the carboxylate O atoms of the L ligands to form a two‐stranded polymeric chain which is assembled into a three‐dimensional supramolecular network through regular interchain O—H...N hydrogen bonding. On excitation at 320 nm, the title compound displays a series of emissions, which were assigned to the characteristic electronic transitions of Tb^III.     

Aqua(oxydiacetato‐κ3O,O′,O′′)(pyridine‐3‐carboxamide‐κN1)copper(II) sesquihydrate

In the monomeric title compound, [Cu(C₄H₄O₅)(C₆H₆N₂O)(H₂O)]·1.5H₂O, the Cu^II cation is bound in a square‐pyramidal coordination to a tridentate oxydiacetate (ODA) ligand, a monodentate pyridine‐3‐carboxamide (p3ca) ligand and one aqua ligand, where the two organic ligands form the basal plane and the water O atom occupies the unique apical site. The ODA ligand presents a slight out‐of‐plane puckering in its central ether O atom, while the p3ca ligand is essentially planar. The availability of efficient donors and acceptors for hydrogen bonding results in the formation of strongly linked hydrogen‐bonded bilayers parallel to (101), with an interplanar distance of 3.18 (1) Å and a stacking separation between the bilayers of 3.10 (1) Å, both of them governed by extended π–π interactions. The disordered nature of the solvent water molecules around inversion centres is discussed. The monoaqua compound is compared with the octahedral diaqua analogue, [Cu(C₄H₄O₅)(C₆H₆N₂O)(H₂O)₂], reported recently [Perec & Baggio (2009). Acta Cryst. C 65 , m296–m298].     

An organometallic RhIII complex with a distorted octahedral structure: (acetonitrile‐κN)dimethyl(1,4,7‐trimethyl‐1,4,7‐triazacyclononane‐κ3N,N′,N′′)rhodium(III) tetraphenylborate

In the title compound, [Rh(CH₃)₂(C₂H₃N)(C₉H₂₁N₃)](C₂₄H₂₀B), the geometry around the Rh^III centre is distorted octahedral, with elongated Rh—N bonds trans to the metal‐bonded methyl groups. The metal‐containing cations are located in channels formed by an anionic supramolecular mesh, in which aromatic π–π interactions between anionic [B(Ph)₄]^? units play a major role.     

Bis(μ‐acetato‐κ3O,O′:O′)bis[bis(acetato‐κ2O,O′)diaquadysprosium(III)] tetrahydrate

The title compound, [Dy₂(C₂H₃O₂)₆(H₂O)₄]·4H₂O, crystallizes in the form of dimeric units related by an inversion centre. Each cation is nine‐coordinate, binding to two water mol­ecules and three acetate groups, two of which are bidentate and the third tridentate. This last acetate group acts as a bridge between neighbouring metal atoms, leading to an intradimer Dy?Dy separation of 4.170 (1) Å.     

A novel one‐dimensional complex: catena‐poly­[[manganese(III)‐di‐μ‐2‐[(2‐hydroxy­ethyl)­imino­methyl]­phenolato‐κ2O1,N:κO2;κO2:κ2O1] chloride]

In the title one‐dimensional complex, {[Mn^III(C₉H₁₀NO₂)₂]Cl}_n, the Schiff base ligand 2‐[(2‐hydroxy­ethyl)­imino­methyl]­phenolate (Hsae⁻) functions as both a bridging and a chelating ligand. The Mn^III ion is six‐coordinated by two N and four O atoms from four different Hsae⁻ ligands, yielding a distorted MnO₄N₂ octahedral environment. Each [Mn^III(Hsae)₂]⁺ cationic unit has the Mn atom on an inversion centre and each [Mn^III(Hsae)₂]⁺ cation lies about another inversion centre. The chain‐like complex is further extended into a three‐dimensional network structure through Cl⋯H—O hydrogen bonds and C—H⋯π contacts involving the Hsae⁻ rings.     

Poly[[diaquabis(μ2‐crotonato‐κ3O:O,O′)(crotonato‐κ2O,O′)lanthanum(III)] adenine monosolvate monohydrate]

The asymmetric unit of the title compound, {[La(C₄H₅O₂)₃(H₂O)₂]·C₅H₅N₅·H₂O}_n, consists of an La^III cation, three crotonate (but‐2‐enoate) anions and two coordinated water molecules forming the neutral complex, completed by an external adenine molecule and one hydration water molecule. The LaO₁₀ coordination polyhedra, connected through the sharing of a single edge, form isolated chains running along the [100] direction. These one‐dimensional structures are characterized by two different centrosymmetric La₂O₂ loops, with La...La distances of 4.5394 (6) and 4.5036 (6) Å. The unbound adenine and water solvent molecules form a highly planar hydrogen‐bonded array parallel to (110) (r.m.s. deviation from the mean plane < 0.10 Å) which intersects the isolated La–crotonate chains in a slanted fashion to form an extremely connected hydrogen‐bonded three‐dimensional structure.     

A novel three‐dimensional heterometallic coordination polymer: poly[[hexaaquabis[μ3‐3,5‐dicarboxylatopyrazolato‐κ5O3,N2:N1,O5:O5′](μ2‐oxalato‐κ4O1,O2:O1′,O2′)copper(II)dierbium(III)] trihydrate]

The title novel heterometallic 3d–4f coordination polymer, {[CuEr₂(C₅HN₂O₄)₂(C₂O₄)(H₂O)₆]·3H₂O}_n, has a three‐dimensional metal–organic framework composed of two types of metal atoms (one Cu^II and two Er^III) and two types of bridging anionic ligands [3,5‐dicarboxylatopyrazolate(3−) (ptc³⁻) and oxalate]. The Cu^II atom is four‐coordinated in a square geometry. The Er^III atoms are both eight‐coordinated, but the geometries at the two atoms appear different, viz. triangular dodecahedral and bicapped trigonal prismatic. One of the oxalate anions is located on a twofold axis and the other lies about an inversion centre. Both oxalate anions act as bis‐bidentate ligands bridging the latter type of Er atoms in parallel zigzag chains. The pdc³⁻ anions act as quinquedentate ligands not only chelating the Cu^II and the triangular dodecahedral Er^III centres in a bis‐bidentate bridging mode, but also connecting to Er^III centres of both types in a monodentate bridging mode. Thus, a three‐dimensional metal–organic framework is generated, and hydrogen bonds link the metal–organic framework with the uncoordinated water molecules. This study describes the first example of a three‐dimensional 3d–4f coordination polymer based on pyrazole‐3,5‐dicarboxylate and oxalate, and therefore demonstrates further the usefulness of pyrazoledicarboxylate as a versatile multidentate ligand for constructing heterometallic 3d–4f coordination polymers with interesting architectures.     

Poly[[aqua(4,4′‐diazenediyldibenzoato‐κ4O,O′:O′′,O′′′)cadmium(II)]: a twofold interpenetrated three‐dimensional coordination polymer of PtS topology

In the title coordination compound, [Cd(C₁₄H₈N₂O₄)(H₂O)]_n, the Cd^II cation and the coordinated water molecule lie on a twofold axis, whereas the ligand lies on an inversion center. The Cd^II center is five‐coordinated in a distorted square‐pyramidal geometry by four carboxylate O atoms from four different 4,4′‐diazenediyldibenzoate (ddb) anions and one water O atom. The three‐dimensional frameworks thus formed by the bridging ddb anions interpenetrate to generate a three‐dimensional PtS‐type network. Additionally, the coordination water molecule and the carboxylate O atom form a hydrogen‐bonding interaction, stabilizing the three‐dimensional framework structure.     

Bis(μ‐3‐nitrobenzene‐1,2‐dicarboxyl­ato)‐κ8O1,O2:O2,O3;O3,O2:O2,O1‐bis­[triaqua­(2‐carboxy‐3‐nitro­benzoato‐κ2O,O′)lanthanum(III)] dihydrate

The title compound, [La₂(C₈H₃NO₆)₂(C₈H₄NO₆)₂(H₂O)₆]·2H₂O, consists of dimeric units related by an inversion center. The two La^III atoms are linked by two bridging bidentate carboxyl­ate groups and two monodentate carboxyl­ate groups. Each La^III atom is nine‐coordinated by six O atoms from five different carboxyl­ate groups and three from water mol­ecules. Hydrogen bonds between the water mol­ecules and between the solvent water and a carboxyl­ate O atom are observed in the structure. In the crystal packing, there are slipped π–π stacking inter­actions between the parallel benzene rings. Both hydrogen‐bonding and π–π inter­actions combine to stabilize the three‐dimensional supra­molecular network.     

(Aqua‐2κO)bis(2,2′‐bipyridine‐1κ2N,N′){μ‐N‐[3‐(dimethylamino)propyl]‐N′‐(2‐oxidophenyl)oxamidato(3−)‐1:2κ2O,O′:κ4O′′,N,N′,N′′}copper(II)nickel(II) perchlorate

The title complex, [CuNi(C₁₃H₁₆N₃O₃)(C₁₀H₈N₂)₂(H₂O)]ClO₄, has a cis‐oxamide‐bridged heterobinuclear cation, with a Cu...Ni separation of 5.3297 (6) Å, counterbalanced by a disordered perchlorate anion. The Cu^II and Ni^II cations are located in square‐pyramidal and octahedral coordination environments, respectively. The complex molecules are assembled into a three‐dimensional supramolecular structure through hydrogen bonds and π–π stacking interactions. The influence of the two types of metal cation on the supramolecular structure is discussed.     

Bis­[tris(2,2′‐bi­pyridine‐κ2N,N′)­ruthenium(II)] hexa­cyano­ferrate(III) chloride octahydrate

In the title compound, [Ru^II(C₁₀H₈N₂)₃]₂[Fe^III(CN)₆]Cl·8H₂O, the [Ru(bpy)₃]²⁺ (bpy is 2,2′‐bi­pyridine) cations and water mol­ecules afford intriguing microporous honeycomb layers, while the [Fe(CN)₆]³⁻ anions and the remainder of the water mol­ecules form anionic sheets based on extensive hydrogen‐bonding networks. The cationic and anionic layers alternate along the c axis. The Fe atom in [Fe(CN)₆]³⁻ lies on an inversion centre and the axial cyano ligands are hydrogen bonded to the water mol­ecules encapsulated within the micropores [N⋯O = 2.788 (5) Å], giving an unusual interpenetration between the cationic and anionic layers. On the other hand, the in‐plane cyano ligands are relatively weakly hydrogen bonded to the water mol­ecules [N⋯O = 2.855 (7) and 2.881 (8) Å] within the anionic sheets.     

Synthesis,crystal structure and magnetic properties of (acetato‐κ2O,O′)bis(5,5′‐dimethyl‐2,2′‐bipyridine‐κ2N,N′)nickel(II) perchlorate monohydrate

The title hydrated ionic complex, [Ni(CH₃COO)(C₁₂H₁₂N₂)₂]ClO₄·H₂O or [Ni(ac)(5,5′‐dmbpy)₂]ClO₄·H₂O (where 5,5′‐dmbpy is 5,5′‐dimethyl‐2,2′‐bipyridine and ac is acetate), (1), was isolated as violet crystals from the aqueous ethanolic nickel acetate–5,5′‐dmbpy–KClO₄ system. Within the complex cation, the Ni^II atom is hexacoordinated by two chelating 5,5′‐dmbpy ligands and one chelating ac ligand. The mean Ni—N and Ni—O bond lengths are 2.0628 (17) and 2.1341 (15) Å, respectively. The water solvent molecule is disordered over two partially occupied positions and links two complex cations and two perchlorate anions into hydrogen‐bonded centrosymmetric dimers, which are further connected by π–π interactions. The magnetic properties of (1) at low temperatures are governed by the action of single‐ion anisotropy, D, which arises from the reduced local symmetry of the cis‐NiO₂N₄ chromophore. The fitting of the variable‐temperature magnetic data (2–300 K) gives g_iso = 2.134 and D/hc = 3.13 cm⁻¹.     

A capped trigonal prismatic cadmium complex with tetra‐ and tridentate ligands: bis­(tri­ethanol­amine)‐κ3N,O,O′;κ4N,O,O′,O′′‐cadmium(II) squarate monohydrate

In the crystal structure of the title compound, [Cd(C₆H₁₅NO₃)₂](C₄O₄)·H₂O, a supramolecular structure is observed. The asymmetric unit consists of one unit of the cationic Cd complex, one water mol­ecule and two half‐squarate anions, each sitting on a crystallographic inversion center. The different coordinations of the two triethanolamine (TEA) ligands results in an unusual example of coordination number seven for the Cd^II ion. Both TEA ligands coordinate to the Cd^II ion, forming a distorted monocapped trigonal prismatic geometry with approximate C_2v symmetry. One of the TEA ligands acts as an N,O,O′‐tridentate ligand, whereas the other behaves as an N,O,O′,O′′‐tetradentate donor. The anions and cations are linked to one another by hydrogen bonds between hydroxy H atoms of the TEA ligands and squarate O atoms. The crystal structure is stabilized by O—H⋯O hydrogen bonds between the unligated water mol­ecule and a squarate O atom, together with a weak π–ring interaction between the ethyl­ene group of a TEA ligand and a squarate anion.     

Synthesis and X‐ray Crystal Structure of Bis[oxamide dioximato‐κ2N,N′](oxamide dioxime‐κ2N,N′)cobalt(III) Perchlorate Hexahydrate

Co(OAc)₂ reacts with oxamide dioxime (H₂oxado) in water in the presence of ClO₄^– ions to produce [Co(Hoxado)₂(H₂oxado)]ClO₄ · 6H₂O ( 1 ), where Hoxado^– is the anion of H₂oxado, derived from the deprotonation of one of the two hydroximinic groups, and in which oxidation of Co^II to Co^III (in air) had occurred. 1 is the first example of a salt in which the cation, [Co(H₂oxado)₃]³⁺, is doubly deprotonated to generate the chiral cation, [Co(Hoxado)₂(H₂oxado)]⁺. The central cobalt cation is pseudo‐octahedrally coordinated by six nitrogen atoms. In the solid state, the complex cations form centro‐symmetric dimers via O–H ··· O bridges. The bulk structure is consolidated by an extended three‐dimensional network of O–H ··· O and N–H ··· O bridges that interconnect the ionic constituents and the water molecules.     

Tetrakis(2,2′‐bipyridine‐κ2N,N′)­tetrakis(μ‐salicyl­ato‐κ3O,O′:O′′)‐quadro‐tetrazinc(II) decahydrate

The title compound, [Zn₄(C₇H₄O₃)₄(C₁₀H₈N₂)₄]·10H₂O, crystallizes as a centrosymmetric tetranuclear cyclic complex containing four Zn^II atoms bridged by four carboxyl­ate groups from salicyl­ate ligands, with a syn–anti configuration. Each Zn^II atom has a distorted trigonal–bipyramidal coordination geometry, formed by two N atoms of a 2,2′‐bipyridine ligand and three O atoms from two salicyl­ate ligands. The complex is stabilized by intramolecular π–π interactions between pairs of bi­pyridine rings and a 16‐membered gear‐wheel‐shaped cyclic framework. The hydrogen‐bonding network is formed via the water mol­ecules.     

Tris­[(R)‐lact­amide‐κ2O,O′]­zinc(II) tetra­bromo­zincate

The title compound, tris­[(R)‐2‐hydroxy­propan­amide‐κ²O,O′]­zinc(II) tetra­bromo­zincate, [Zn(C₃H₇NO₂)₃][ZnBr₄], contains one monomeric six‐coordinate zinc complex cation and one tetrahedral [ZnBr₄]²⁻ anion. Both Zn^II atoms lie on threefold axes. Coordination in the cation occurs via the amide and hydroxy O atoms [Zn—O = 2.074 (5) and 2.073 (6) Å] and has a distorted octahedral geometry, with cis‐O—Zn—O angles in the range 76.2 (2)–109.2 (2)°. In the crystal structure, the cations and anions are linked by N—H⋯Br and O—H⋯O hydrogen bonds, generating a three‐dimensional network.     

(Acetato‐κ2O,O′)dihydroxidoytterbium(III) hemihydrate

The title compound, [Yb(C₂H₃O₂)(OH)₂]·0.5H₂O, was obtained via hydrothermal reaction of Yb(CH₃COO)₃·H₂O with NaOH at 443 K. The compound forms two‐dimensional layers with six crystallographically independent Yb^III atoms. Four of these form YbO₈ coordination polyhedra, while the coordination number of the remaining two Yb^III atoms is 7. Five of these coordination polyhedra are interconnected mainly via hydroxide groups, as they build a narrow inner layer that extends infinitely within the ab plane. The sixth Yb^III atom resides outside this inner layer and builds a terminal YbO₈ coordination polyhedron on the layer surface. Its coordination environment comprises four carboxylate O atoms belonging to three different acetate entities, three hydroxide groups and one water molecule. Adjacent layers experience weak interactions via hydrogen bonds. The Yb—O distances lie in the range 2.232 (4)–2.613 (5) Å.     

A novel dinuclear bismuth(III) coordination compound: bis(μ‐pyridine‐2,6‐dicarboxylato)‐κ4O2,N,O6:O6′;κ4O2:O2′,N,O6‐bis[(azido‐κN)(1,10‐phenanthroline‐κ2N,N′)bismuth(III)] tetrahydrate

A novel dinuclear bismuth(III) coordination compound, [Bi₂(C₇H₃NO₄)₂(N₃)₂(C₁₂H₈N₂)₂]·4H₂O, has been synthesized by an ionothermal method and characterized by elemental analysis, energy‐dispersive X‐ray spectroscopy, IR, X‐ray photoelectron spectroscopy and single‐crystal X‐ray diffraction. The molecular structure consists of one centrosymmetric dinuclear neutral fragment and four water molecules. Within the dinuclear fragment, each Bi^III centre is seven‐coordinated by three O atoms and four N atoms. The coordination geometry of each Bi^III atom is distorted pentagonal–bipyramidal (BiO₃N₄), with one azide N atom and one bridging carboxylate O atom located in axial positions. The carboxylate O atoms and water molecules are assembled via O—H...O hydrogen bonds, resulting in the formation of a three‐dimensional supramolecular structure. Two types of π–π stacking interactions are found, with centroid‐to‐centroid distances of 3.461 (4) and 3.641 (4) Å.