Tetra­ammonium benzene‐1,2,4,5‐tetra­carboxyl­ate tetrahydrate

The anions in the title compound, 4NH₄⁺·C₁₀H₂O₈^4?·4H₂O, are held together by regular hydrogen bonds from the carboxyl­ate O atoms to the ammonium cations and water mol­ecules, forming a three‐dimensional network.     

cis,cis,cis‐Tetra­methyl 1,2,4,5‐cyclo­hexane­tetra­carboxyl­ate

The title compound, C₁₄H₂₀O₈, was synthesized from the hydrogenation of tetra­methyl 1,4‐cyclo­hexa­diene‐1,2,4,5‐tetra­carboxyl­ate with a catalytic amount of palladium/carbon. All four carbonyl moieties of the methyl ester groups are on the same face of the chair‐conformed ring. The substantial ring distortion associated with the 1,3‐diaxial methoxycarbonyl substituents is reflected in the large difference between bond angles as well as torsion angles, respectively, that in undistorted cyclo­hexanes would be approximately the same.     

C—H⋯O interactions in diethyl 5,5′,6,6′‐tetra­methyl­bi­phenyl‐2,2′‐di­carboxyl­ate at 193 K

The title compound, C₂₂H₂₆O₄, crystallized in the centrosymmetric space group P with one mol­ecule as the asymmetric unit. Three leading intermolecular C—H?O interactions have H?O distances of 2.71, 2.73 (2) and 2.71 (2) Å and C—H?O angles of 167, 137.0 (15) and 163.1 (12)°. These interactions form ring and chain patterns. The bi­phenyl twist angle is 79.95 (6)°.     

Tetra­aqua(3,4,7,8‐tetra­methyl‐1,10‐phenanthroline‐κ2N,N′)­zinc(II) thio­sulfate

In the title complex of zinc(II) with 3,4,7,8‐tetra­methyl‐1,10‐phenanthroline (tmph), viz. [Zn(C₁₆H₁₆N₂)(H₂O)₄](S₂O₃), the metal atom has a monomeric octahedral ZnN₂O₄ complex environment comprising two N‐atom donors from the tmph group and four aqua O‐atom donors. The complex cation is connected to four thio­sulfate anions through a compact hydrogen‐bonding network involving all coordinated aqua H‐atom donors and all the outer acceptors (O and S) of the anion.     

Tetra­aqua(2,2′‐bi­pyridine)­nickel(II) terephthalate

The reaction of nickel(II) nitrate with terephthalic acid and 2,2′‐bi­pyridine in di­methyl­form­amide solution gives the title complex, [Ni(C₁₀H₈N₂)(H₂O)₄](C₈H₄O₄). The Ni^II ion is octahedrally coordinated to one 2,2′‐bi­pyridine and four water mol­ecules and does not coordinate to the terephthalate anion. Hydro­gen bonds between the terephthalate anions and the [Ni(2,2′‐bipy)(H₂O)₄]²⁺ cations produce a two‐dimensional hydrogen‐bonding architecture with double sheets.     

Ethyl 5‐methyl‐4‐(2,5,5‐tri­methyl‐1,3‐dioxan‐2‐yl)­isoxazole‐3‐carboxyl­ate

The title compound, C₁₄H₂₁NO₅, possesses an isoxazolyl group in the axial position of the 1,3‐dioxanyl ring. The two rings are rotated about the bond joining them such that the two C(methyl)—C(dioxanyl)—C—C torsion angles are 92.1 (2) and ?84.1 (2)°. In this conformation, neither the methyl nor ethoxy­carbonyl substituents on the isoxazole are presented towards the dioxanyl chair.     

{2,2′‐[1,1′‐(4‐Aza­heptane‐1,7‐diyl­dinitrilo)diethyl­idyne]­diphenolato}­copper(II)

The quinquedentate ligand 2,2′‐[1,1′‐(4‐aza­heptane‐1,7‐diyl­dinitrilo)diethyl­idyne]diphenol in the title compound, [Cu(C₂₂H₂₇N₃O₂)], furnishes an N₃O₂ donor set, which results in a distorted square‐pyramidal coordination; the two O and two imine N atoms lie in the basal plane, while the secondary amine N atom of the ligand occupies the axial position. The axial Cu—N bond is 0.33 Å longer than the average of the equatorial bonds, and the O atoms are trans. The symmetry of the mol­ecule is lowered by the twist–boat and chair conformations adopted by the two CuNN chelate rings. The complex contains two intra­molecular C—H⋯O inter­actions, and two mol­ecules of the complex are linked into a dimer by means of moderate N—H⋯O hydrogen bonds. Spectroscopic evidence supports the presence of hydrogen bonds.     

Benzene‐1,2,4,5‐tetra­carboxyl­ic acid–trans‐cinnam­amide (1/2)

In the title adduct, C₁₀H₆O₈·2C₉H₉NO, benzene‐1,2,4,5‐tetra­car­box­ylic acid has a crystallographic twofold axis parallel to b and forms a flat zigzag chain along c linked by O— H?O cyclic hydrogen bonds with cinnam­amide mol­ecules.     

trans‐Di­aqua(C‐meso‐5,12‐di­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane‐N,N′,N′′,N′′′)copper(II) dichloride dihydrate

The crystal structure of the title complex, [Cu(C₁₂H₂₈N₄)(H₂O)₂]Cl₂·2H₂O, has been determined. The Cu^II atom is octahedrally coordinated by the four N atoms of the tetradentate macrocyclic ligand in equatorial positions and by the O atoms of two water mol­ecules in axial positions. The crystal structure is stabilized by a three‐dimensional network of hydrogen bonds.     

Bis(2,4,7‐tri­methyl­indenyl)­cobalt(II) and rac‐2,2′,4,4′,7,7′‐hexamethyl‐1,1′‐biindene

The crystal and molecular structures of bis(η⁵‐2,4,7‐tri­methyl­indenyl)­cobalt(II), [Co(C₁₂H₁₃)₂], (I), and rac‐2,2′,4,4′,7,7′‐hexamethyl‐1,1′‐biindene, C₂₄H₂₆, (II), are reported. In the crystal structure of (I), the Co atom lies on an inversion centre and the structure represents the first example of a bis(indenyl)cobalt complex exhibiting an eclipsed indenyl conformation. The (1R,1′R) and (1S,1′S) enantiomers of the three possible stereoisomers of (II), which form as by‐products in the synthesis of (I), cocrystallize in the monoclinic space group P2₁/c. In the unit cell of (II), alternating (1R,1′R) and (1S,1′S) enantiomers pack in non‐bonded rows along the a axis, with the planes of the indenyl groups parallel to each other and separated by 3.62 and 3.69 Å.     

3,3′‐Dihydr­oxy‐5,5,5′,5′‐tetra­methyl‐2,2′‐thio­dicyclo­hex‐2‐en‐1‐one

Mol­ecules of the title compound, C₁₆H₂₂O₄S, have twofold crystallographic symmetry and are stabilized by strong intra­molecular O—H⋯O hydrogen bonds and very weak inter­molecular C—H⋯O hydrogen bonds, forming layers normal to the c axis. The mol­ecular structure is compared with those of the Se‐ and CH₂‐bridged analogues.     

fac‐Tri­carbonyl(4,4′‐di­methyl‐2,2′‐bi­pyridine)­tri­phenyl­tin(II)­rhenium(I)

The title organometallic compound, fac‐tri­carbonyl‐2κ³C‐(4,4′‐di­methyl‐2,2′‐bi­pyridine)‐2κ²N,N′‐tri­phenyl‐1κ³C¹‐tin(II)­rhenium(I)(Sn—Re), [ReSn(C₆H₅)₃(C₁₂H₁₂N₂)(CO)₃], con­tains three unique π–π stacking interactions. The result is an infinite chain of uninterrupted alternating intra‐ and intermolecular offset π–π stacking interactions throughout the crystal lattice. This extended π–π stacking arrangement, and an additional isolated intramolecular π–π interaction between the remaining 4,4′‐di­methyl‐2,2′‐bi­pyridine ring and a second phenyl group, impose geometric constraints on the Re and Sn atoms, yielding distorted octahedral and tetrahedral coordinations, respectively, for the metal centers.     

Chains of fused rings in the hydrogen‐bonded structure of meso‐­6,13‐di­amino‐6,13‐di­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane–2,2′‐biphenol (1/2)

The title compound is a salt, [C₁₂H₃₂N₆]²⁺·2[HOC₆H₄C₆H₄O]^?. The centrosymmetric cation contains two intramolecular N—H?N hydrogen bonds with an N?N distance of 2.8290 (13) Å, and the pendent amino groups are in axial sites; the anion contains an intramolecular O—H?O hydrogen bond with an O?O distance of 2.4656 (11) Å. The ions are linked into continuous chains by means of four types of N—H?O hydrogen bonds with N?O distances ranging from 2.7238 (12) Å to 3.3091 (13) Å, associated with N—H?O angles in the range 148–160°.     

Three methoxy‐substituted diethyl 4‐­phenyl‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate compounds

Diethyl 4‐(2,5‐di­methoxy­phenyl)‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₁H₂₇NO₆, (I), diethyl 4‐(3,4‐di­methoxy­phenyl)‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₁H₂₇NO₆, (II), and diethyl 2,6‐di­methyl‐4‐(3,4,5‐tri­methoxy­phenyl)‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₂H₂₉NO₇, (III), crystallize with hydrogen‐bonding networks involving the H atom bonded to the N atom of the 1,4‐di­hydro­pyridine ring and carbonyl O atoms in (I) and (II). Unusually, (III) shows O atoms of methoxy groups serving as hydrogen‐bond acceptors.     

(μ‐C‐meso‐5,5,7,12,12,14‐Hexa­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane‐N‐acetato‐1κ5N,N′,N′′,N′′′,O:2κO′)­tetra­chloro‐1κCl,2κ3Cl‐cobalt(III)­zinc(II)

The crystal structure of the title compound, [CoCl(C₁₈H₃₇N₄O₂){ZnCl₃}], has been determined by X‐ray diffraction.C‐meso‐5,5,7,12,12,14‐Hexa­methyl‐1,4,8,11‐tetra­aza­cyclotetradecane‐N‐acetate acts as a bridging ligand to coodinate with Co^III and Zn^II ions. The Co^III ion is six‐coordinate in a nearly octahedral environment provided by one Cl atom, four N atoms of the bridging ligand, and one O atom. The Zn^II ion is four‐coordinate in a distorted tetrahedral environment completed by three Cl atoms and an O atom of the bridging ligand.     

Di‐μ‐acetato‐bis­[bis(4‐amino­benzoato)(2,2′‐bipyridyl)­manganese(II)]

In the title compound, [Mn₂(C₇H₆NO₂)₂(C₂H₃O₂)₂(C₁₀H₈N₂)₂], the two Mn^II atoms are each coordinated by one 2,2′‐bi­pyridyl mol­ecule, one 4‐amino­benzoate ion and two acetate ions. The two Mn atoms exhibit different coordination environments: one is coordinated by two N and four O atoms, while the other is coordinated by two N and three O atoms. The two Mn atoms are bridged by two acetate ions in a syn–anti mode, with an Mn⋯Mn distance of 4.081 (1) Å.     

Solid‐State Electrochemistry and Electrochemiluminescence of Porous Thin Film of [(2,2′‐Bipyridyl)(4‐(2‐pyrrol‐1‐ylethyl)‐4′‐methyl‐2,2′‐bipyridyl)2]ruthenium(II) Monomer Precipitation

A novel fluorescent porous thin film based on the precipitation of the [(2,2′‐bipyridyl)(4‐(2‐pyrrol‐1‐ylethyl)‐4′‐methyl‐2,2′‐bipyridyl)₂]ruthenium(II) (BF₄)₂ complex (pyr‐Ru) was fabricated by easily spreading 2 µL of pyr‐Ru (1 mM in acetonitrile solution) onto the surface of a platinum electrode and drying it in ambient conditions. The morphology of the resulting pyr‐Ru thin film was characterized by scanning electron microscopy (SEM) and fluorescence microscopy. The coating exhibits fluorescent properties of the ruthenium complex and a porous structure with pore diameters of micrometers. The solid‐state electrochemistry and electrochemiluminescence behaviors of the porous pyr‐Ru thin film were investigated in aqueous solution by cyclic voltammetry and step potential.     

Di­methyl 2‐(4‐bromo­phenyl)‐10,11‐di­methoxy‐2,3,7,8‐tetra­hydro­spiro­[azepino[2,1‐a]­iso­quinoline‐3,9′‐fluorene]‐4,5‐di­carboxyl­ate

The title compound, C₃₈H₃₂BrNO₆, is a new photochromic tetra­hydro­azepinoiso­quinoline (THAI). The longest spiro bond [1.589 (4) Å] can be broken very easily by UV light, leading to ring opening. This explains the photochromic behaviour.     

Poly­[[di­aqua­tris(μ6‐benzene‐1,2,4,5‐tetra­carboxyl­ato)­tris(μ2‐4,4′‐bi­pyridine)­hexacopper(II)] dihydrate]

The hydro­thermal reaction of an aqueous solution of Cu(CH₃COO)₂·H₂O, 1,2,4,5‐benzene­tetra­carboxylic acid and 4,4′‐bi­pyridine gave rise to the interesting title three‐dimensional polymer {[Cu₆(btec)₃(4,4′‐bpy)₃(H₂O)₂]·2H₂O}_n (btec is 1,2,4,5‐benzene­tetra­carboxyl­ate, C₁₀H₂O₈⁴⁻, and 4,4′‐bpy is 4,4′‐bi­pyridine, C₁₀H₈N₂), in which each btec ligand links six copper(II) cations into a lamellar [Cu₆(btec)₃(H₂O)₂]_n sub­polymer framework. There are two distinct diamine units and two distinct carboxylate units, with one of each lying across an inversion centre.     

Bis(2,2′‐bi­pyridine‐κ2N,N′)(1,10‐phen­anthroline‐κ2N,N′)­ruthenium(II) tetra­cyano­platinate(II)

In the title compound, [Ru(C₁₀H₈N₂)₂(C₁₂H₈N₂)][Pt(CN)₄], cations and anions alternate along the a axis to afford a one‐dimensional network. The one‐dimensional character arises from the π–π stacking as well as from the electrostatic interactions formed between the phen (1,10‐phenanthroline) and [Pt(CN)₄]²⁻ units. Two adjacent one‐dimensional chains form further stacks based on the π–π stacking interactions between the phen moieties, where the interplanar spacing is 3.50 (1) Å.