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.     

A new polymorphic form of bis(acetato‐κO)bis[2‐(pyridin‐2‐yl)ethanol‐κ2N,O]nickel(II)

A new polymorph of a mononuclear nickel(II) acetate complex with 2‐(pyridin‐2‐yl)ethanol ligands, [Ni(CH₃COO)₂(C₇H₉NO)₂], has been prepared and structurally characterized. Its molecular structure resembles the structures of two previously reported polymorphs in that the Ni^II atom is located on an inversion centre and is coordinated by pairs of acetate and 2‐(pyridin‐2‐yl)ethanol ligands. The acetate anions are coordinated in a monodentate manner, while the 2‐(pyridin‐2‐yl)ethanol ligands are coordinated in a bidentate chelating mode involving the endocyclic N atom and the hydroxy O atom of the ligand side chain. A strong bifurcated intramolecular hydrogen‐bond interaction was observed involving the hydroxy O atom as donor and both acetate O atoms as acceptors. No classical intermolecular hydrogen‐bond contacts were observed. However, the crystal packing is effected through π–π and C—H...π interactions, giving rise to a different packing arrangement. A brief comparison of the three polymorphic forms is presented.     

Poly[bis[μ2‐3‐(pyridin‐4‐yl)benzoato‐κ3N:O,O′]lead(II)]

In the title compound, [Pb(C₁₂H₈NO₂)₂]_n, the Pb atom sits on a crystallographic C₂ axis and is six‐coordinate, ligated by two chelating carboxylate groups from two 3‐(pyridin‐4‐yl)benzoate (L) ligands and by two N atoms from another two ligands. Each ligand bridges two Pb^II centres, extending the structure into a corrugated two‐dimensional (4,4) net. The ligand L is conformationally chiral, with a torsion angle of 27.9 (12)° between the planes of its two rings. The torsion angle has the same sense throughout the structure, so that the extended two‐dimensional polymer is homochiral. Investigation of the thermal stability shows that the network is stable up to 613 K. In the absence of any stereoselective factor in the preparation of the compound, the enantiomeric purity of the crystal studied, based only on the torsional conformation of the ligand, implies that the bulk sample is a racemic conglomerate.     

Poly[di‐μ‐aqua‐μ‐1,2‐bis(pyridin‐4‐yl)ethene‐κ2N:N′‐tetrakis(4‐iodobenzoato‐κ2O,O′)dicadmium]

Colourless crystals of the title compound, [Cd₂(C₇H₄IO₂)₄(C₁₂H₁₀N₂)(H₂O)₂]_n, were obtained by the self‐assembly of Cd(NO₃)₂·4H₂O, 1,2‐bis(pyridin‐4‐yl)ethene (bpe) and 4‐iodobenzoic acid (4‐IBA). Each Cd^II atom is seven‐coordinated in a pentagonal–bipyramidal coordination environment by four carboxylate O atoms from two different 4‐IBA ligands, two O atoms from two water molecules and one N atom from a bpe ligand. The Cd^II centres are bridged by the aqua molecules and bpe ligands, which lie across centres of inversion, to give a two‐dimensional net. Topologically, taking the Cd^II atoms as nodes and the μ‐aqua and μ‐bpe ligands as linkers, the two‐dimensional structure can be simplified as a (6,3) network.     

Tetrakis(μ‐benzoato‐κ2O:O)bis{[4‐(dimethylamino)pyridine‐κN1]copper(II)}

The title compound, [Cu₂(C₇H₅O₂)₄(C₇H₁₀N₂)₂], is a crystallographically centrosymmetric binuclear complex, with Cu atoms [Cu...Cu = 2.6982 (4) Å] bridged by four benzoate ligands. Each of the Cu atoms in this bunuclear copper(II) acetate hydrate analogue is present in an approximately square‐pyramidal environment, with four O atoms in a plane and the pyridine N atom at the apical site. Selected geometric parameters are compared with values for related tetrabenzoate complexes of copper(II).     

Chloridobis[2‐(diphenylphosphanyl)ethanamine‐κ2P,N](triphenylphosphane‐κP)ruthenium(II) chloride toluene monosolvate

The aminophosphane ligand 1‐amino‐2‐(diphenylphosphanyl)ethane [Ph₂P(CH₂)₂NH₂] reacts with dichloridotris(triphenylphosphane)ruthenium(II), [RuCl₂(PPh₃)₃], to form chloridobis[2‐(diphenylphosphanyl)ethanamine‐κ²P,N](triphenylphosphane‐κP)ruthenium(II) chloride toluene monosolvate, [RuCl(C₁₈H₁₅P)(C₁₄H₁₆NP)₂]Cl·C₇H₈ or [RuCl(PPh₃){Ph₂P(CH₂)₂NH₂}₂]Cl·C₇H₈. The asymmetric unit of the monoclinic unit cell contains two molecules of the Ru^II cation, two chloride anions and two toluene molecules. The Ru^II cation is octahedrally coordinated by two chelating Ph₂P(CH₂)₂NH₂ ligands, a triphenylphosphane (PPh₃) ligand and a chloride ligand. The three P atoms are meridionally coordinated, with the Ph₂P– groups from the ligands being trans. The two –NH₂ groups are cis, as are the chloride and PPh₃ ligands. This chiral stereochemistry of the [RuCl(PPh₃){Ph₂P(CH₂)₂NH₂}₂]⁺ cation is unique in ruthenium–aminophosphane chemistry.     

Exo conformers of N‐(pyridin‐2‐yl)‐ and N‐(pyridin‐3‐yl)norbornene‐5,6‐dicarboximide crystals

Two isomeric pyridine‐substituted norbornenedicarboximide derivatives, namely N‐(pyridin‐2‐yl)‐exo‐norbornene‐5,6‐dicarboximide, (I), and N‐(pyridin‐3‐yl)‐exo‐norbornene‐5,6‐dicarboximide, (II), both C₁₄H₁₂N₂O₄, have been crystallized and their structures unequivocally determined by single‐crystal X‐ray diffraction. The molecules consist of norbornene moieties fused to a dicarboximide ring substituted at the N atom by either pyridin‐2‐yl or pyridin‐3‐yl in an anti configuration with respect to the double bond, thus affording exo isomers. In both compounds, the asymmetric unit consists of two independent molecules (Z′ = 2). In compound (I), the pyridine rings of the two independent molecules adopt different conformations, i.e. syn and anti, with respect to the methylene bridge. The intermolecular contacts of (I) are dominated by C—H...O interactions. In contrast, in compound (II), the pyridine rings of both molecules have an anti conformation and the two independent molecules are linked by carbonyl–carbonyl interactions, as well as by C—H...O and C—H...N contacts.     

Poly[[bis(pyridin‐3‐ol)manganese(II)]‐di‐μ‐pyridin‐3‐olato]

In the title complex, [Mn(C₅H₄NO)₂(C₅H₅NO)₂]_n or [Mn(μ‐3‐PyO)₂(3‐PyOH)₂]_n (3‐PyO⁻ is the pyridin‐3‐olate anion and 3‐PyOH is pyridin‐3‐ol), the Mn^II atom lies on an inversion centre and has octahedral geometry, defined by two N atoms and two deprotonated exocyclic O atoms of symmetry‐related pyridin‐3‐olate ligands [Mn—N = 2.3559 (14) Å and Mn—O = 2.1703 (11) Å], as well as two N atoms of terminal 3‐PyOH ligands [Mn—N = 2.3482 (13) Å]. The Mn^II atoms are bridged by the deprotonated pyridin‐3‐olate anion into a layer structure, generating sheets in the (01) plane. These sheets are linked by O—H⋯O hydrogen bonds. There are also π–π and C—H⋯π interactions in the crystal structure.     

Poly[[μ2‐1,3‐bis(pyridin‐4‐yl)propane](μ3‐1,4‐phenylenediacetato)cadmium]

Solvothermal reaction between Cd(NO₃)₂, 1,4‐phenylenediacetate (1,4‐PDA) and 1,3‐bis(pyridin‐4‐yl)propane (bpp) afforded the title complex, [Cd(C₁₀H₈O₄)(C₁₃H₁₄N₂)]_n. Adjacent carboxylate‐bridged Cd^II ions are related by an inversion centre. The 1,4‐PDA ligands adopt a cis conformation and connect the Cd^II ions to form a one‐dimensional chain extending along the c axis. These chains are in turn linked into a two‐dimensional network through bpp bridges. The bpp ligands adopt an anti–gauche conformation. From a topological point of view, each bpp ligand and each pair of 1,4‐PDA ligands can be considered as linkers, while the dinuclear Cd^II unit can be regarded as a 6‐connecting node. Thus, the structure can be simplified to a two‐dimensional 6‐connected network.     

Poly[bis{μ2‐4‐[3,5‐bis(pyridin‐4‐yl)phenyl]pyridine}nona‐μ2‐oxido‐tetraoxidocopper(II)tetramolybdenum(VI)]

The title compound, [CuMo₄O₁₃(C₂₁H₁₅N₃)₂]_n, was synthesized by the reaction of ammonium molybdate, copper acetate and 4‐[3,5‐bis(pyridin‐4‐yl)phenyl]pyridine (DPPP) in an aqueous medium under hydrothermal conditions. The two unique molybdenum centers and the copper center adopt MoO₄ tetrahedral, MoO₅N octahedral and CuO₄N₂ octahedral geometries, respectively. These polyhedra are connected to each other through corner‐sharing to form a two‐dimensional Cu–Mo–O layer, which is further linked by the DPPP ligands to form the three‐dimensional inorganic–organic hybrid framework.     

The first dinuclear cobalt complex bridged by acetylamidate ligands: di‐μ‐acetylamido‐κ2O:N;κ2N:O‐di‐μ‐hydroxido‐κ4O:O‐bis[bis(pyridine‐κN)cobalt(III)] bis(perchlorate) acetonitrile disolvate

The title compound, [Co₂(C₂H₄NO)₂(OH)₂(C₅H₅N)₄](ClO₄)₂·2C₂H₃N, consists of two octahedral Co^III centers arranged around an inversion point in which two cis hydroxide and two trans acetylamidate ligands link the two centers together, forming a dimeric cationic complex. Each Co^III center has two cis pyridine ligands which coordinate in the same plane as the cis hydroxide ligands. Two acetonitrile solvent molecules and two perchlorate anions are hydrogen bonded to the H atoms on the bridging hydroxide and acetylamidate (N atom) ligands, respectively.     

A fourfold interpenetrating diamondoid three‐dimensional coordination polymer: poly[[[μ2‐1,2‐bis(pyridin‐4‐yl)ethene‐κ2N:N′](μ2‐5‐hydroxyisophthalato‐κ2O1:O3)zinc(II)] 1,2‐bis(pyridin‐4‐yl)ethene hemisolvate]

In the title compound, {[Zn(C₈H₄O₅)(C₁₂H₁₀N₂)]·0.5C₁₂H₁₀N₂}_n or {[Zn(HO‐BDC)(bpe)]·0.5bpe}_n [HO‐H₂BDC is 5‐hydroxyisophthalic acid and bpe is 1,2‐bis(pyridin‐4‐yl)ethene], the asymmetric unit contains a Zn^II atom, one HO‐BDC ligand, one coordinated bpe ligand and half a noncoordinating bpe molecule with crystallographic inversion symmetry. Each Zn^II centre is four‐coordinated by two O atoms from two distinct HO‐BDC ligands and two N atoms from two different bpe ligands in a ZnO₂N₂ coordination environment. The three‐dimensional topology of the title compound corresponds to a fourfold interpenetrating diamondoid coordination polymer network, with the uncoordinated bpe ligands located in the cavities, hydrogen bonded to the main network via the hydroxy group of the HO‐H₂BDC ligand.     

Bis[μ‐1‐(1,10‐phenanthrolin‐2‐yl)‐2‐pyridone]bis{aqua[1‐(1,10‐phenanthrolin‐2‐yl)‐2‐pyridone]cadmium(II)} tetrakis(perchlorate)

In the title centrosymmetric binuclear complex, [Cd₂(C₁₇H₁₁N₃O)₄(H₂O)₂](ClO₄)₄, the Cd^II ion assumes a distorted octahedral geometry. There are π–π stacking interactions between the pyridine and 1,10‐phenanthroline ring systems of adjacent ligands at the same Cd^II centre. Intermolecular hydrogen bonds between the coordinated aqua ligand and the O atom of a keto group connect adjacent complex cations into extended chains. Hydrogen bonds also exist between the complex cations and the perchlorate anions. Compared with the fluorescence spectrum of the organic ligand, the complex displays strong fluorescent emission and an ipsochromic shift of the emission peaks, which may be attributed to the structural character.     

Bromidobis[2‐(pyridin‐2‐yl)methanol‐κ2N,O]copper(II) bromide monohydrate

The title compound, [CuBr(C₆H₇NO)₂]Br·H₂O, is an ionic mononuclear complex in which the [CuBr(C₆H₇NO)₂]⁺ cation possesses distorted square‐pyramidal geometry. The Cu^II centre is coordinated by two neutral 2‐(pyridin‐2‐yl)methanol (2‐pyMeOH) ligands and a terminal bromide ligand. The 2‐pyMeOH ligands are coordinated in a bidentate chelating manner through the pyridine N and hydroxy O atoms, forming a five‐membered chelate ring with the Cu^II centre. The planes of the pyridine rings are twisted by 58.71 (14)° with respect to each other. The charge is balanced by a noncoordinating bromide anion which, together with a solvent water molecule, links the components through hydrogen bonds into infinite chains propagating along the a axis. The mononuclear cations appear to associate in pairs through weak interactions between the metal atom of one cation and the halogen atom of an adjacent cation.     

Ethylenediammonium bis{bis[N‐(2‐aminoethyl)glycinato‐κ3N,N′,O]chromium(III)} tetrachloride dihydrate at 293 and 100 K

The crystal structure of the title compound, (C₂H₁₀N₂)[Cr(C₄H₉N₂O₂)₂]₂Cl₄·2H₂O, has been determined by single‐crystal X‐ray diffraction studies at 293 and 100 K. The analyses demonstrated that the crystal consists of ethyl­enedi­ammonium dications (which lie about inversion centres), bis­[N‐(2‐amino­ethyl)­glycin­ato]­chromium(III) monocations, Cl^? anions and hydrate water mol­ecules, in a molecular ratio of 1:2:4:2. The complex cation unit has a slightly distorted octahedrally coordinated Cr atom, with two Cr—O and four Cr—N bonds in the ranges 1.951 (1)–1.953 (1) and 2.054 (1)–2.089 (2) Å, respectively, at 293 K. The geometry of the bis­[N‐(2‐amino­ethyl)­glycinato]­chromium(III) moiety was found to be trans,cis,cis with respect to the carboxyl­ate O atom and the primary and secondary amine N atoms. The two analyses, at 293 and 100 K, exhibited no remarkable structural differences, although the colour of the crystals did differ, being red at 293 K and orange at 100 K.     

Bis[μ3‐1,8‐bis(triisopropylsilylamido)naphthalene]bis(tetrahydrofuran)di‐μ3‐oxido‐dimanganese(III)disodium

The solid‐state structure of the title compound, [Na₂Mn₂(C₃₂H₅₆N₂OSi₂)₂O₂] or [1,8‐C₁₀H₆(NSiⁱPr₃)₂Mn(μ₃‐O)Na(THF)]₂, which lies across a crystallographic twofold axis, exhibits a central [Mn₂O₂Na₂]⁴⁺ core, with two oxide groups, each triply bridging between the two Mn^III ions and an Na⁺ ion. Additional coordination is provided to each Mn^III centre by a 1,8‐C₁₀H₆(NSiⁱPr₃)₂ [1,8‐bis(triisopropylsilylamido)naphthalene] ligand and to the Na⁺ centres by a tetrahydrofuran molecule. The presence of an additional Na...H—C agostic interaction potentially contributes to the distortion around the bridging oxide group.     

Tris[3,6‐di‐tert‐butyl‐1‐(isoquinolin‐1‐yl)naphthalen‐2‐olato‐κ2N,O]aluminium(III) toluene sesquisolvate

The central Al^III atom of the title compound, [Al(C₂₇H₂₈NO)₃]·1.5C₇H₈, has octahedral geometry in which the three N atoms are arranged in a meridional fashion. One of the toluene solvent molecules is located on a general position, while the second is disordered around a centre of inversion. The ligand molecule has axial chirality, and two of the three ligands in the complex exhibit the same stereochemistry. The three independent chelate rings exhibit significantly different bite angles at the metal atom, with one [83.72 (8)°] notably smaller than the other two [87.22 (8) and 87.13 (8)°]. Calculation of the solid angle covered by the ligands at the metal atom reveals that coverage is greatest for the ligand group with the shortest Al—O bond distance.     

The three‐dimensional coordination network in poly[di‐μ3‐cyanido‐μ5‐[5‐(pyridin‐4‐yl)tetrazolato]‐tricopper(I)]

In the title three‐dimensional tetrazolate‐based coordination polymer, poly[bis(μ₃‐cyanido‐κ³N:C:C)[μ₅‐5‐(pyridin‐4‐yl)tetrazolato‐κ⁵N:N′:N′′:N′′′:N′′′′]tricopper(I)], [Cu₃(C₆H₄N₅)(CN)₂]_n, there are two types of coordinated Cu^I atoms. One type exhibits a tetrahedral environment and the other, residing on a twofold axis, adopts a trigonal coordination environment. The closest Cu...Cu distance is only 2.531 (2) Å, involving a bridging cyanide C atom. All four tetrazolate and the pyridine N atom of the 4‐(pyridin‐4‐yl)‐1H‐tetrazolate anion are coordinated to these Cu^I atoms and exhibit a μ₅‐bridging mode. The three‐dimensional coordination network can be topologically simplified as a rarely observed (3,3,4,5)‐connected network with the Schläfli symbol (4.6.8⁴)₂.(4².6.8⁷).(6.8²)₃.     

catena‐Poly[[[diaquazinc]‐bis{μ‐N2,N6‐bis[(pyridin‐3‐yl)methyl]pyridine‐2,6‐dicarboxamide}] dinitrate]

In the title compound, {[Zn(C₁₉H₁₇N₅O₂)₂(H₂O)₂](NO₃)₂}_n, the Zn^II cation is located at an inversion centre within a slightly distorted octahedron, ligated by four N atoms from four N²,N⁶‐bis[(pyridin‐3‐yl)methyl]pyridine‐2,6‐dicarboxamide (L) ligands occupying a plane about the Zn^II atom with the two water O atoms perpendicular to that. In the complex molecule, the bidentate bridging L ligands display helical R and S conformers, and link the Zn^II cations into a one‐dimensional centrosymmetric double‐chain structure containing 32‐membered rings. The nitrate anions reside in these rings and are involved in multiple N—H...O hydrogen‐bond interactions. On excitation at 390 nm, the title compound displays a strong blue emission centred at 449 nm. Investigation of the thermal stability shows that the network structure is stable up to 420 K.     

Polymorphism of 3‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)‐ and 3‐[5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazol‐2‐yl]‐2H‐chromen‐2‐ones

This study of 3‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)‐2H‐chromen‐2‐one, C₁₇H₁₀N₂O₃, 1 , and 3‐[5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazol‐2‐yl]‐2H‐chromen‐2‐one, C₁₆H₉N₃O₃, 2 , was performed on the assumption of the potential anticancer activity of the compounds. Three polymorphic structures for 1 and two polymorphic structures for 2 have been studied thoroughly. The strongest intermolecular interaction is stacking of the `head‐to‐head' type in all the studied crystals. The polymorphic structures of 1 differ with respect to the intermolecular interactions between stacked columns. Two of the polymorphs have a columnar or double columnar type of crystal organization, while the third polymorphic structure can be classified as columnar‐layered. The difference between the two structures of 2 is less pronounced. Both crystals can be considered as having very similar arrangements of neighbouring columns. The formation of polymorphic modifications is caused by a subtle balance of very weak intermolecular interactions and packing differences can be identified only using an analysis based on a study of the pairwise interaction energies.