Bis(3‐amino­pyridine‐κN)(4,4′‐di­methyl‐2,2′‐bipyridine‐κ2N,N′)(per­chlorato‐κO)copper(II) per­chlorate

The title compound, [Cu(ClO₄)(C₅H₆N₂)₂(C₁₂H₁₂N₂)]ClO₄, was prepared by in situ partial ligand substitution between 3‐amino­pyridine and 4,4′‐dimethyl‐2,2′‐bipyridine at room temperature. The central copper(II) ion is five‐coordinated by one bidentate 4,4′‐dimethyl‐2,2′‐bipyridine mol­ecule, two monodentate pyridine‐coordinated 3‐amino­pyridine mol­ecules and one apical O atom from the perchlorate counter‐ion. Inter­molecular N—H⋯O and C—H⋯O hydrogen‐bonding inter­actions form a hydrogen‐bond‐sustained network.     

6‐(3,4‐Di­fluoro­benzoyl)‐3‐[2‐(4‐pyridyl)­ethyl]‐1,3‐benzo­thia­zol‐2(3H)‐one

A new type of benzo­thia­zolinone derivative with potential pharmacological activity, viz. 6‐(3,4‐di­fluoro­benzoyl)‐3‐[2‐(4‐pyridyl)­ethyl]‐1,3‐benzo­thia­zol‐2(3H)‐one, C₂₁H₁₄F₂N₂O₂S, has been prepared and studied by NMR, IR and single‐crystal X‐ray diffraction techniques. The mol­ecule is not planar, the pyridine and di­fluoro­benzene moieties being located above and below the benzo­thia­zole ring system. The carbonyl O atoms are involved in an intramolecular hydrogen‐bond‐type interaction.     

3‐Methyl 5‐isopropyl 2‐methoxy­imino­methyl‐6‐methyl‐4‐(3‐nitro­phenyl)‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate

The crystal structure of the title compound, C₂₀H₂₃N₃O₇, consists of relatively isolated mol­ecules. The substituted 1,4‐di­hydro­pyridine ring adopts a flattened boat conformation. Both ester groups, at positions 3 and 5, have cis,cis geometry. The phenyl ring is nearly planar and is approximately perpendicular to the 1,4‐di­hydro­pyridine ring (dihedral angle 87.70°).     

Supramolecular structures of three isomeric 4‐(methyl­phenylamino)­pyridine‐3‐sulfonamides

The structures of the three title isomers, namely 4‐(2‐methyl­anilino)pyridine‐3‐sulfonamide, (I), 4‐(3‐methyl­anilino)pyridine‐3‐sulfonamide, (II), and 4‐(4‐methyl­anilino)pyridine‐3‐sulfonamide, (III), all C₁₂H₁₃N₃O₂S, differ in their hydrogen‐bonding arrangements. In all three mol­ecules, the conformation of the 4‐amino­pyridine‐3‐sulfon­amide moiety is conserved by an intra­molecular N—H⋯O hydrogen bond and a C—H⋯O inter­action. In the supra­mol­ecular structures of all three isomers, similar C(6) chains are formed via inter­molecular N—H⋯N hydrogen bonds. N—H⋯O hydrogen bonds lead to C(4) chains in (I), and to R₂²(8) centrosymmetric dimers in (II) and (III). In each isomer, the overall effect of all hydrogen bonds is to form layer structures.     

Bis(acesulfamato‐κO4)diaqua­bis­(3‐methyl­pyridine‐κN)nickel(II)

In the crystal structure of the title compound [systematic name: diaqua­bis(6‐methyl‐2,2‐dioxo‐1,2,3‐oxathia­zin‐4‐olato‐κO⁴)bis­(3‐methyl­pyridine‐κN)nickel(II)], [Ni(C₄H₄NO₄S)₂(C₆H₇N)₂(H₂O)₂], the Ni^II centre resides on a centre of symmetry and has a distorted octa­hedral geometry. The basal plane is formed by two carbonyl O atoms of two monodentate trans‐oriented acesulfamate ligands and two trans aqua ligands. The axial positions in the octa­hedron are occupied by two N atoms of two trans pyridine ligands. Mol­ecules are stacked in columns running along the a axis. There are π–π stacking inter­actions between the mol­ecules in each column, with a distance of 3.623 (2) Å between the centroids of the pyridine rings. There are also O—H⋯O inter­actions between the columns.     

catena‐Poly[bis[(η2‐1‐allyl‐3‐aminopyridinium)copper(I)]‐di‐μ‐chloro‐copper(I)‐di‐μ‐chloro‐copper(I)‐di‐μ‐chloro]

Crystals of the title π‐complex, [Cu₄Cl₆(C₈H₁₁N₂)₂]_n, were obtained by means of alternating‐current electrochemical synthesis. The structure consists of infinite copper–chlorine chains to which 1‐allyl‐3‐amino­pyridinium moieties are attached via a η² Cu—(C=C) interaction. The two independent Cu atoms have distinct coordination environments. One is three‐coordinate, surrounded by two chloro ligands and the olefinic bond, whereas the second copper center is surrounded by a tetrahedral arrangement of four Cl atoms. The lower basicity of 3‐amino­pyridine as compared with 2‐ and 4‐amino­pyridine lowers the capacity of the organic ligand for donating to N—H⋯Cl hydrogen bonds and results in the formation of a large inorganic fragment.     

A single‐strand helical coordination polymer: catena‐poly­[[[tri­aqua­nickel(II)]‐μ‐2,2′‐bi­pyridine‐3,3′‐di­carboxyl­ato‐κ3N,N′:O] monohydrate]

The asymmetric unit of the title compound, {[Ni(C₁₂H₆N₂O₄)(H₂O)₃]·H₂O}_n, is composed of a lattice water mol­ecule and a nickel(II) ion that is coordinated by three water mol­ecules and the two N atoms of a 2,2′‐bi­pyridine‐3,3′‐di­carboxyl­ate ligand. The twist of the 2,2′‐bi­pyridine‐3,3′‐di­carboxyl­ate unit and the coordination of one carboxyl­ate group to a symmetry‐related Ni^II atom generate a helical chain that runs along the b axis. Intrahelical hydrogen bonds participate in controlling the orientation of the helices, and both right‐handed and left‐handed helices are connected by interhelical hydrogen bonds into two‐dimensional sheets.     

Tetrakis(μ‐2,3‐dimethoxybenzoato)bis[(2,2′‐bipyridine)(2,3‐dimethoxybenzoato)lanthanum(III)]

The title compound, tetrakis(μ‐2,3‐di­methoxy­benzoato)‐κ⁴O:O′;κ⁶O,O′:O′‐bis[(2,2′‐bi­pyridine‐N,N′)(2,3‐di­methoxy­benzoato‐O,O′)lanthanum(III)], [La₂(2,3‐DMOBA)₆(2,2′‐bpy)₂], where 2,3‐DMOBA is 2,3‐di­methoxy­benzoate (C₉H₉O₄) and 2,2′‐bpy is 2,2′‐bi­pyridine (C₁₀H₈N₂), is a dimer with a centre of inversion between the La atoms bridged by four carboxyl­ate ligands. The central La atom is ennea‐coordinated and has a distorted monocapped square‐antiprism geometry.     

Sodium pyridine‐3‐carboxyl­ate

The title compound, also known as sodium nicotinate, Na⁺·C₆H₄NO₂⁻, consists of two unique Na atoms coordinated to two unique pyridine‐3‐­carboxyl­ate ligands through the N atoms and carboxylate groups. One Na atom and one pyridine‐3‐­carboxyl­ate ligand lie on a twofold axis. Extensive Na coordination results in a three‐dimensional array comprising infinite NaO₂CR chains linked by intrachain Na—N bonds.     

Magnesium iodide–4,4′‐bipyridine–water (1/3/4) and strontium iodide–4,4′‐bipyridine–propan‐1‐ol (1/2.5/2)

Both of the title compounds, catena‐poly­[[[tetra­aqua­magnesium(I)]‐μ‐4,4′‐bi­pyridine‐κ²N:N′] diiodide bis(4,4′‐bi­pyridine) solvate], {[Mg(C₁₀H₈N₂)(H₂O)₄]I₂·2C₁₀H₈N₂}_n, (I), and catena‐poly­[[[μ‐4,4′‐bi­pyridine‐bis­[di­iodo­bis­(propan‐1‐ol)­strontium(I)]]‐di‐μ‐4,4′‐bi­pyridine‐κ⁴N:N′] bis(4,4′‐bi­pyri­dine) solvate], {[Sr₂I₄(C₁₀H₈N₂)₃(C₃H₈O)₄]·2C₁₀H₈N₂}_n, (II), are one‐dimensional polymers which are single‐ and double‐stranded, respectively, the metal atoms being linked by the 4,4′‐bi­pyridine moieties. The Mg complex, (I), is [cis‐{(H₂O)₄Mg(N‐4,4′‐bi­pyridine‐N′)_(2/2)}]_(∞|∞)I₂·4,4′‐bi­pyridine and Mg has a six‐coordinate quasi‐octahedral coordination environment. The Sr complex, (II), is isomorphous with its previously defined Ba counterpart [Kepert, Waters & White (1996). Aust. J. Chem. 49 , 117–135], being [(propan‐1‐ol)₂I₂Sr(N‐4,4′‐bi­pyridine‐N′)_(3/2)]_(∞|∞)·4,4′‐bi­pyridine, with the I atoms trans‐axial in a seven‐coordinate pentagonal–bipyramidal Sr environment.     

N,N‐Diethyl‐2,6,6‐trimethyl‐4‐(3‐nitrophenyl)‐5‐oxo‐1,4,5,6,7,8‐hexahydroquinoline‐3‐carboxamide

The title compound, C₂₃H₂₉N₃O₄, has potential calcium modulatory properties. The conformation of the 1,4‐di­hydro­pyridine ring is unusual in that it is planar, instead of the usual shallow boat. The 3‐nitro­phenyl substituent is in the synperiplanar orientation with respect to the di­hydro­pyridine ring plane. The oxo­cyclo­hexene ring has a distorted envelope conformation, with the out‐of‐plane atom being disordered on opposite sides of the ring plane. The mol­ecules are linked into chains by intermolecular hydrogen bonds.     

catena‐Poly[[chloro­dipyridine­manganese(II)]‐μ3‐6‐oxo‐1,6‐dihydro­pyridine‐2‐carboxyl­ato]

The title one‐dimensional chain polymer complex, [Mn(C₆H₄NO₃)Cl(C₆H₅N)₂]_n, was isolated from the reaction of MnCl₂ with 6‐oxo‐1,6‐dihydro­pyridine‐2‐carboxylic acid (HpicOH) in pyridine. The asymmetric unit contains one [Mn(HPicO)Cl(py)₂] moiety (py is pyridine), with the (HpicO)⁻ ligand acting in a tridentate manner via the two carboxyl­ate O atoms and the pyridone O atom. The operation of inversion centres generates eight‐ and 14‐membered rings and, in conjunction with an a‐axis translation, leads to an infinite chain extending along [100]. The Mn⋯Mn separations in this chain are 5.1069 (6) and 7.1869 (6) Å. The Mn^II atom has a distorted octahedral coordination, with trans‐axial pyridine ligands and with three O atoms and the Cl atom in the equatorial plane. The conformation of the 14‐membered ring is stabilized by pairs of inversion‐related N—H⋯O hydrogen bonds.     

Poly­[[di­aqua­cobalt(II)]‐μ‐4,4′‐bi­pyridine‐κ2N:N′‐μ‐p‐phenyl­enebis­(oxy­acetato)‐κ2O:O′]

The title compound, [Co^II(C₁₀H₈O₆)(C₁₀H₈N₂)(H₂O)₂]_n, was obtained by the hydro­thermal reaction of CoSO₄ with benzene‐1,4‐dioxy­di­acetate [systematic name: p‐phenyl­ene­bis­(oxy­acetate)] and 4,4′‐bi­pyridine (4,4′‐bpy). The Co atom lies at an inversion center and the benzene‐1,4‐dioxydiacetate and 4,4′‐bipyridine moieties lie about other inversion centers. The benzene‐1,4‐dioxydiacetate ligands bridge the octahedral Co^II coordination centers, forming a one‐dimensional zigzag chain. The chains are further bridged by 4,4′‐bpy ligands, forming a novel two‐dimensional supramolecular architecture. Hydro­gen‐bonding interactions between the coordinated water mol­ecules and the carboxyl­ate O atoms lead to the formation of a three‐dimensional network structure.     

Methyl 4‐(2‐chloro‐5‐nitro­phenyl)‐2,7,7‐tri­methyl‐5‐oxo‐1,4,5,6,7,8‐hexa­hydro­quinoline‐3‐carboxyl­ate

The title compound, C₂₀H₂₁ClN₂O₅, has potential calcium modulatory properties. The 1,4‐di­hydro­pyridine ring has the usual shallow boat conformation. The 2‐chloro‐5‐nitro­phenyl ring is oriented such that the chloro substituent is in a synperiplanar orientation with respect to the 1,4‐di­hydro­pyridine ring plane, while the nitro substituent sits over the 1,4‐di­hydro­pyridine ring. The cyclo­hexenone ring has a conformation that is approximately half‐way between that of an envelope and that of a half‐chair. The mol­ecules are linked into chains by intermolecular N—H⋯O hydrogen bonds.     

(μ‐2,11‐Dithia­[3.3]paracyclo­phane‐κ2S:S′)bis­[(6‐carboxy­pyridine‐2‐carboxylato‐κ2N,O6)silver(I)]: a mixed‐ligand silver‐based dinuclear compound

In the title complex, [Ag₂(C₇H₄NO₄)₂(C₁₆H₁₆S₂)], each Ag^I atom is trigonally coordinated by one S atom of a 2,11‐dithia­[3.3]paracyclo­phane (dtpcp) ligand, and by one N and one O atom of a 6‐carboxy­pyridine‐2‐carboxylate ligand. Dtpcp acts as a bidentate ligand, bridging two inversion‐related Ag^I atoms to give a dinuclear silver(I) compound. The dinuclear moieties are inter­connected via O—H·O hydrogen bonds to form a two‐dimensional zigzag sheet. Two such sheets are inter­woven viaπ–π inter­actions between pyridine rings, affording an inter­woven bilayer network.     

[2,6‐Bis(1H‐benzimidazol‐2‐yl‐κN3)­pyridine‐κN](di­methyl­form­amide‐κO)­(thio­sulfato‐κ2O,S)­nickel(II) mono­hydrate

The structure of the title compound, [Ni(ths)(bbip)(dmf)]·­H₂O [ths is thio­sulfate, S₂O₃; bbip is 2,6‐bis(1H‐benz­imidazol‐2‐yl)­pyridine, C₂₁H₁₃N₅; and dmf is di­methyl­form­amide, C₃H₇NO], is monomeric, with the nickel ion octahe­drally surrounded by an N,N′,N′′‐tridentate bbip mol­ecule, an S,O‐bidentate ths mol­ecule and an O‐monodentate dmf mol­ecule. The H atoms of the hydration water mol­ecule and the amino groups of bbip are involved in hydrogen bonding and determine a spatial organization of broad layers parallel to (001), which are connected by weak interactions.     

3,5‐Di­fluoro‐4‐nitro­pyridine N‐oxide and 3,5‐di­amino‐4‐nitro­pyridine N‐oxide monohydrate

The mol­ecule of 3,5‐di­fluoro‐4‐nitro­pyridine N‐oxide, C₅H₂F₂N₂O₃, is twisted around the C—NO₂ bond by 38.5 (1)°, while the 3,5‐di­amino analogue, 3,5‐di­amino‐4‐nitro­pyridine N‐oxide monohydrate, C₅H₆N₄O₃·H₂O, adopts a planar conformation stabilized by intramolecular hydrogen bonds, with a significant redistribution of π electrons.     

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.     

Polymeric di­aqua­bis­[μ4‐1,3,5‐benzenetri­carboxyl­ato(3–)](μ‐4,4′‐bi­pyridine)­trizinc(II)

The solvothermal reaction of zinc(II) acetate with 1,3,5‐benzene­tri­carboxyl­ic acid and 4,4′‐bi­pyridine in 1‐butanol and acetic acid solution gives the title complex, [Zn₃(C₉H₃O₆)₂(C₁₀H₈N₂)(H₂O)₂]_n. There are two different coordination environments for the Zn atom, namely ZnNO₂(H₂O) and ZnO₄; in the latter case, the Zn atom lies on a twofold symmetry axis. Carboxyl­ate‐bridged Zn₃(O₂C)₆ clusters are connected through 1,3,5‐benzene­tri­carboxyl­ate and 4,4′‐bi­pyridine ligands (which lie about inversion centers), yielding a three‐dimensional framework.     

Transition metal complexes with thiosemicarbazide‐based ligands. XLIV. Aqua(3‐hydroxy‐5‐hydroxymethyl‐2‐methylpyridine‐4‐carboxaldehyde 3‐­methylisothiosemicarbazone‐κ3O,N1,N4)nitratocopper(II) nitrate

The title complex, [Cu(NO₃)(C₁₀H₁₄N₄O₂S)(H₂O)](NO₃), is the first metal complex with a Schiff base derived from iso­thio­semicarbazide and pyridoxal (pyridoxal is 3‐hydroxy‐5‐­hydroxy­methyl‐2‐methyl­pyridine‐4‐carbox­aldehyde). The Cu^II environment is a square pyramid, the equatorial plane of which is formed by the tridentate ONN‐coordinated iso­thio­semicarbazone and one water mol­ecule, while the nitrate ligand is in the apical position. The existence of numerous strong intermolecular hydrogen bonds, and weak C—H?O and C—H?π interactions, leads to a three‐dimensional supramolecular structure.