Poly[3-methyl-pyridinium [(µ2-di-hydrogen phosphito)bis(µ3-hydrogen phosphito)dizinc]].

In the title compound, {(C6H8N)[Zn2(HPO3)2(H2PO3)]}n, the constituent ZnO4, HPO3 and H2PO3 polyhedra of the inorganic component are linked into (010) sheets by Zn-O-P bonds (mean angle = 134.4°) and the layers are reinforced by O-H⋯O hydrogen bonds. The protonated templates are anchored to the inorganic sheets via bifurcated N-H⋯(O,O) hydrogen bonds.

Chiral Thianthrenes.

The absolute configuration and stability of two thianthrene chiral sulfoxides has been determined by means of X-ray single-crystal structure determinations. The analyses and configurations allow verification that the diastereomeric sulfoxides are stable in solution and are not interconverting, which has been suggested in some studies of sulfoxides. The two thianthrene sulfoxides have slightly different Rf values, which allowed their separation using flash chromatography on silica. The spots run back-to-back, which posed a challenge for their separation. The pure, separated compounds in solution remain as separate, single spots on a Thin Layer Chromatography (TLC) plate.

New Functionalized Phenoxazines and Phenothiazines.

The reaction of either 2-aminophenol or 2-(N-methylamino)phenol with 1,2-difluoro-4,5-dinitrobenzene and sodium carbonate in EtOH gives 2,3-dinitrophenoxazines. One nitro group, conjugated to the aryl ether, was displaced from 2,3-dinitro-10-methylphenoxazine with different nucleophiles: BuNH2, KOEt, and KOH. The reaction of 2-aminothiophenol with 1,2-difluoro-4,5-dinitrobenzene under the same conditions gives 2,3-dinitrophenothiazine. This reacted with BuNH2 forming 2-butylamino-3-nitrophenothiazine. The dihedral angles of the different compounds are compared.

Porous and Close Packed Supramolecular Assemblies from 2,4-Difluoronitrobenzene with Three Different Linkers and an n-Butylamine Cap.

A porous structure formed from sheets with cavities and two close packed structures were crystallised from building blocks prepared from 2,4-difluoronitrobenzene, a diamine linker and n-butylamine. The porous structure crystallised from a flexible building block prepared using 1,4-diaminobutane as linker. The close packed structures were prepared using either piperazine or 1,4-bis(aminomethyl)benzene as a linker and have less conformational freedom.

Consistent zincophosphite 4-ring 'ladder' chain structural motif with isomeric ligands.

The syntheses and crystal structures of four hydro-thermally prepared organo-zinc phosphites, viz. poly[[(2-amino-3-methyl-pyridine)-µ3-phospho-nato-zinc] hemihydrate], {[Zn(HPO3)(C6H8N2)]·0.5H2O} n , (I), poly[(2-amino-4-methyl-pyridine)-µ3-phospho-nato-zinc], [Zn(HPO3)(C6H8N2)] n , (II), poly[(2-amino-5-methyl-pyridine)-µ3-phospho-nato-zinc], [Zn(HPO3)(C6H8N2)] n , (III), and poly[bis-(2-amino-4-methyl-pyridinium) [tetra-µ3-phospho-nato-trizinc] monohydrate], {(C6H9N2)2[Zn3(HPO3)4]·H2O} n , (IV), are described. Compounds (I)-(III) are constructed from vertex-sharing ZnO3N tetra-hedra (the organic mol-ecule acting as a ligand) and HPO3 pseudo pyramids in a 1:1 ratio to generate the same motif of infinite 4-ring 'ladder' chains propagating in the [010], [101] and [100] directions, respectively, whereas (IV) consists of (010) layers of vertex-sharing ZnO4 and HPO3 units in a 3:4 ratio with the protonated organic mol-ecule acting as a template. When an excess of HCl is used in the synthesis, the simple hydrated mol-ecular salt, bis-(2-amino-3-methyl-pyridinium) tetra-chloro-zincate monohydrate, (C6H8N2)2[ZnCl4]·H2O, (V), arises. Com-pounds (I)-(V) feature extensive networks of hydrogen bonds, both classical (N-H⋯O, N-H⋯Cl, O-H⋯O) and non-classical (C-H⋯O, C-H⋯Cl) in nature, which help to consolidate the extended structures.

Heterocyclic Synthesis of Crowded Aposafranones: Structure of 1-Methyl-8-dimethylamino-10-phenylphenazin-2-(10H)one and Related Compounds.

Oxidative condensation of three p-phenylenediamines with 3-hydroxy-2-methyl-N-(phenylamino)benzene gives new coloured aposafranones. 2-Methylresorcinol is easy to convert into the asymmetric building block 3-hydroxy-2-methyl-N-(phenylamino)benzene with aniline. The aposafranones are sterically crowded because of the 1-methyl and N-phenyl groups. The UV/Vis absorption maxima are in the range 530-545 nm.

Different conformations and packing motifs in the crystal structures of four thio-phene-carbohydrazide-pyridine derivatives.

The crystal structures of four thio-phene-carbohydrazide-pyridine derivatives, viz. N'-[(E)-pyridin-3-yl-methyl-idene]thio-phene-2-carbohydrazide, C11H9N3OS, (I), N'-[(E)-pyridin-2-yl-methyl-idene]thio-phene-2-carbohydrazide, C11H9N3OS, (II), N-methyl-N'-[(E)-pyridin-2-yl-methyl-idene]thio-phene-2-carbohydrazide, C12H11N3OS, (III) and N'-[(E)-pyridin-2-yl-methyl-idene]-2-(thio-phen-2-yl)ethano-hydrazide, C12H11N3OS, (IV) are described. The dihedral angles between the thio-phene ring and the pyridine ring are 21.4 (2), 15.42 (14), 4.97 (8) and 83.52 (13)° for (I)-(IV), respectively. The thio-phene ring in (IV) is disordered over two orientations in a 0.851 (2):0.149 (2) ratio. Key features of the packing include N-H⋯Np (p = pyridine) hydrogen bonds in (I), which generate C(7) chains propagating in the [001] direction; N-H⋯Np links also feature in (II), but in this case they lead to C(6) [001] chains; in (IV), classical amide (C4) N-H⋯O links result in [010] chains; in every case adjacent mol-ecules in the chains are related by 21 screw axes. There are no classical hydrogen bonds in the extended structure of (III). Various weak C-H⋯X (X = O, N, S) inter-actions occur in each structure, but no aromatic π-π stacking is evident. The Hirshfeld surfaces and fingerprint plots for (I)-(IV) are compared.

Flux syntheses and single-crystal structures of CsNa10 M 4(AsO4)9 (M = Zr, Hf).

The isostructural compounds caesium deca-sodium tetra-zirconium nona-arsenate, CsNa10Zr4(AsO4)9, and caesium deca-sodium tetra-hafnium nona-arsenate, CsNa10Hf4(AsO4)9, arose as unexpected single-crystal products from the reactions of Na2CO3, MO2 (M = Zr, Hf) and As2O5 in a eutectic flux of NaCl and CsCl. They consist of MO6 octa-hedra and AsO4 tetra-hedra sharing vertices to generate three-dimensional polyhedral networks encapsulating the caesium and sodium ions. The MO6 groups share all their vertices with adjacent As atoms but the As atoms have one or two 'terminal' O atoms not bonded to Zr or Hf. The Cs+ ion adopts a squashed octa-hedral geometry and the coordination polyhedra of the partially occupied sodium ions are variously trigonal bipyramidal, tetra-hedral, square pyramidal and trigonal pyramidal. Site symmetries: Cs ; M 3; As 1 and 2; O 1; Na 1, 2 and 3. The M = Zr crystal was refined as an obverse/reverse rhombohedral twin.

Potential Building Blocks for 1,4-Dihydro-N-heteroacenes.

Studies have been performed aimed at the synthesis of N-heteroacenes via substitution reactions of 4,5-difluoro-1,2-dinitrobenzene with a diamine. The fluorine atoms are displaced first, followed by an activated nitro group. Two intermediates have been characterised by X-ray single-crystal structure determinations. Their intermolecular interactions were examined by Hirshfeld surfaces to assess their suitability for organic molecular electronics. The high reactivity of the phenazine, which is prone to oxidise and rearrange, as are displacement products prepared from it, is explained by the formation of a cis-aci-nitro form from the secondary amine of the phenazine and a nitro group.

A Potential Iterative Approach to 1,4-Dihydro-N-Heteroacene Arrays.

A new method for the synthesis of substituted 1,4-dihydrophenazines is reported and the structure of N-butyl-5-methyl-3-nitro-5,10-dihydrophenazine is proven by an X-ray single-crystal structure determination.

Crystalline Forms of Trazodone Dihydrates.

In this study, treatment of anhydrous trazodone powder with ammonium carbamate in warm water crystallised two new polymorphs or dihydrates of trazodone after 5 h, whose structures were determined by X-ray single crystal diffraction. Each dihydrate contains infinite zigzag hydrogen-bonded chains of water molecules, which are stabilised by the N4 acceptor atom of the piperazine ring and the pendant carbonyl O1 atom of the triazole ring, as well as other water molecules. The strong dipole moment expected for the O1 atom makes it a good hydrogen bond acceptor for stabilising the chains of water molecules. Each molecule of trazodone has a similar conformation in both hydrates, except for the propyl chains, which adopt different conformations: anti-gauche in the ß hydrate (triazole N-C-C-C and C-C-C-piperazine N) and anti-anti in the γ hydrate. Both piperazine rings adopt chair conformations, and the exocyclic N-C bonds are in equatorial orientations. The Hirshfeld surfaces and two-dimensional fingerprint plots for the polymorphs were calculated using CrystalExplorer17, which indicated contacts significantly shorter than the sum of the van der Waals radii in the vicinity of the piperazine N4 and triazole O1 atoms corresponding to the strong hydrogen bonds accepted by these atoms.

Understanding the remarkable difference in liquid crystal behaviour between secondary and tertiary amides: the synthesis and characterisation of new benzanilide-based liquid crystal dimers.

A number of liquid crystal dimers have been synthesised and characterised containing secondary or tertiary (N-methyl) benzanilide-based mesogenic groups. The secondary amides all form nematic phases, and we present the first example of an amide to show the twist-bend nematic (NTB) phase. Only two of the corresponding N-methylated dimers formed a nematic phase and with greatly reduced nematic-isotropic transition temperatures. Characterisation using 2D ROESY NMR experiments, DFT geometry optimisation and X-ray diffraction reveal that there is a change in the preferred conformation of the benzanilide core on methylation, from Z to E. The rotational barrier around the N-C(O) bond has been measured using variable temperature 1H NMR spectroscopy. This dramatic change in shape accounts for the remarkable difference in liquid crystalline behaviour between these secondary and tertiary amide-based materials.

Hydro-thermal synthesis and crystal structure of poly[bis-(µ3-3,4-di-amino-benzoato)manganese], a layered coordination polymer.

The hydro-thermal synthesis and crystal structure of the title two-dimensional coordination polymer, poly[bis-(µ3-3,4-di-amino-benzoato-κ3 N 3,O,O')manganese(II)], [Mn(C7H7N2O2)2] n , are described. The Mn2+ cation (site symmetry ) adopts a tetra-gonally elongated trans-MnN2O4 octa-hedral coordination geometry and the µ3-N,O,O' ligand (bonding from both carboxyl-ate O atoms and the meta-N atom) links the metal ions into infinite (10) layers. The packing is consolidated by intra-layer N-H⋯O and inter-layer N-H⋯N hydrogen bonds. The structure of the title compound is compared with other complexes containing the C7H7N2O2 - anion and those of the related M(C8H8NO2)2 (M = Mn, Co, Ni, Zn) family, where C8H8NO2 - is the 3-amino-4-methyl-benzoate anion.

Different packing motifs in the crystal structures of three mol-ecular salts containing the 2-amino-5-carb-oxy-anilinium cation: C7H9N2O2 +·Cl-, C7H9N2O2 +·Br- and C7H9N2O2 +·NO3 -·H2O.

The syntheses and crystal structures of three mol-ecular salts of protonated 3,4-di-amino-benzoic acid, viz. 2-amino-5-carb-oxy-anilinium chloride, C7H9N2O2 +·Cl-, (I), 2-amino-5-carb-oxy-anilinium bromide, C7H9N2O2 +·Br-, (II), and 2-amino-5-carb-oxy-anilinium nitrate monohydrate, C7H9N2O2 +·NO3 -·H2O, (III), are described. The cation is protonated at the meta-N atom (with respect to the carb-oxy group) in each case. In the crystal of (I), carb-oxy-lic acid inversion dimers linked by pairwise O-H⋯O hydrogen bonds are seen and each N-H group forms a hydrogen bond to a chloride ion to result in (100) undulating layers of chloride ions bridged by the inversion dimers into a three-dimensional network. The extended structure of (II) features O-H⋯Br, N-H⋯Br and N-H⋯O hydrogen bonds: the last of these generates C(7) chains of cations. Overall, the packing in (II) features undulating (100) sheets of bromide ions alternating with the organic cations. Inter-molecular inter-actions in the crystal of (III) include O-H⋯O, O-H⋯(O,O), N-H⋯O, N-H⋯N and O-H⋯N links. The cations are linked into (001) sheets, and the nitrate ions and water mol-ecules form undulating chains. Taken together, alternating (001) slabs of organic cations plus anions/water mol-ecules result. Hirshfeld surfaces and fingerprint plots were generated to give further insight into the inter-molecular inter-actions in these structures. The crystal used for the data collection of (II) was twinned by rotation about [100] in reciprocal space in a 0.4896 (15):0.5104 (15) ratio.

Lone-pair self-containment in pyritohedron-shaped closed cavities: optimized hydrothermal synthesis, structure, magnetism and lattice thermal conductivity of Co15F2(TeO3)14.

A new oxofluoride Co15F2(TeO3)14 has been prepared by optimized hydrothermal synthesis involving a complex mineralization process. The crystal structure consists of a three-dimensional network of CoO5(O,F) octahedra, distorted CoO5 square pyramids, TeO3 trigonal pyramids and grossly distorted TeO3+3 octahedra, which are linked by sharing corners and edges. The Te(iv) lone pairs are accommodated within novel pyritohedron-shaped [(TeO3)14]28- units. This special framework provides a much larger free space that allows Te atoms to vibrate with a large amplitude, which leads to extremely low lattice thermal conductivity. Magnetic susceptibility data for Co15F2(TeO3)14 show antiferromagnetic ordering below 9.6 K with a substantial orbital component to the effective magnetic moment. An S = 3/2 honeycomb-like spin network was carefully analyzed by experimental techniques and first principles calculations.

Synthesis, crystal structures and, magnetic and photoluminescence properties of lanthanide-based metal-organic frameworks constructed with 2,5-dihydroxybenzene-1,4-dicarboxylic acid.

Four new lanthanide(iii) coordination polymers (1-4) have been synthesized by using 2,5-dihydroxybenzene-1,4-dicarboxylate (Dhbdc, C8H6O6 2-) as a ligand and characterized by elemental analysis, infrared spectroscopy, TGA-DSC (Thermogravimetric Analysis-Differential Scanning Calorimetry) and single crystal X-ray diffraction studies. The isolated complexes include; [Ce(Dhbdc)(H2O)3Cl] n (1) and [Ln(Dhbdc)1.5(H2O)2] n ·3n(C2H6O)·nH2O [Ln = Eu (2), Gd (3) and Tb (4)]. The structural analysis reveals that compound 1 is a two-dimensional polymer in which the cerium atoms are coordinated by six oxygen and two bridging chloride ions adopting a dodecahedral geometry. The compounds 2-4 are isomorphous and their extended structures consist of three-dimensional supramolecular frameworks encapsulating [001] channels occupied by the guest water and ethanol molecules. The metal atoms in 2-4 exhibit a square antiprism geometry. All these compounds have O-H⋯O hydrogen bonds originating from the coordinated water and solvent molecules that help to consolidate the structures. The compounds 1, 3 and 4 were investigated for magnetic properties and they exhibited weak antiferromagnetic coupling interactions between the lanthanides as per the Curie Weiss law. Anisotropic nature of 3 and 4 has been depicted as per magnetization versus field plots. Complex 4 behaves as a soft magnetic material as compared to 3. The luminescence studies indicate that compounds 2, 3 and 4 show ligand-centred fluorescence, which is significantly enhanced in the case of 4.

Photochemical Fragmentation of Irgacure PAG 103.

Photoisomerization of Irgacure PAG 103 followed by photocyclization and fragmentation leads to three tricyclic thieno[2,3-b]quinoline-4-carbonitrile heterocyclic compounds. The release of acid which can catalyze polymer resist modifications is indicated by the low pH of an aqueous extract. These reactions are discussed in view of possible mechanisms and how these might influence future design strategies.

Synthesis, Crystal Structures and Photoluminescent Properties of One-Dimensional Europium(III)- and Terbium(III)-Glutarate Coordination Polymers, and Their Applications for the Sensing of Fe3+ and Nitroaromatics.

Two lanthanide-glutarate coordination polymers, viz. : {[Eu(C5H6O4)(H2O)4]Cl} n , (1) and [Tb(C5H7O4)(C5H6O4)(H2O)2] n , (2) have been synthesized and characterized by IR spectroscopy, thermogravimetric analysis, and X-ray crystallography. In 1, the Eu(III) ions are coordinated by four O atoms from two bidentate chelating carboxylate groups, one O atom from a bridging carboxylate group and four O atoms from water molecules adopting an EuO9 distorted tri-capped trigonal prismatic coordination geometry. In 2, the Tb(III) ions are coordinated by six O atoms from three bidentate chelating carboxylates, one O atom from a bridging carboxylate and two O atoms from water molecules to generate distorted tri-capped trigonal prismatic TbO9 polyhedron. In both compounds, the metal polyhedra share edges, producing centrosymmetric Ln2O2 diamonds, and are linked into [001] chains by bridging glutarate di-anions. The crystal structures are consolidated by O-H···O and O-H···Cl hydrogen bonds in 1, and O-H···O hydrogen bonds in 2. Compound 1 exhibits a red emission attributed to the 5D0 → 7F J (J = 1-4) transitions of the Eu(III) ion, whereas 2 displays green emission corresponding to the 5D4 → 7F J (J = 0-6) transitions of the Tb(III) ion. Both the compounds exhibit high sensitivity and selectivity for Fe3+ ions due to luminescence quenching compared with other metal ions, which include; Na+, Mg2+, Al3+, Cr3+, Mn2+, Fe2+, Co2+, Ni2+, Zn2+ and Cd2+. Compounds 1 and 2 also show high luminescence quenching sensitivity for 4-nitrophenol over the other aromatic and nitroaromatic compounds, namely; bromobenzene, 1,3-dimethylbenzene, nitrobenzene, 4-nitrotolune, 4-nitrophenol, 2,6-dinitrophenol and 2,4,6-trinitrophenol.

Different packing motifs mediated by weak inter-actions and polymorphism in the crystal structures of five 2-(benzyl-idene)benzosuberone derivatives.

The syntheses and crystal structures of five 2-benzyl-idene-1-benzosuberone [1-benzosuberone is 6,7,8,9-tetra-hydro-5H-benzo[7]annulen-5-one] derivatives, viz. 2-(4-meth-oxy-benzyl-idene)-1-benzosuberone, C19H18O2, (I), 2-(4-eth-oxy-benzyl-idene)-1-benzosuberone, C20H20O2, (II), 2-(4-benzyl-benzyl-idene)-1-benzosuberone, C25H22O2, (III), 2-(4-chloro-benzyl-idene)-1-benzosuberone, C18H15ClO, (IV) and 2-(4-cyano-benzyl-idene)-1-benzosuberone, C19H15NO, (V), are described. The conformations of the benzosuberone fused six- plus seven-membered ring fragments are very similar in each case, but the dihedral angles between the fused benzene ring and the pendant benzene ring differ somewhat, with values of 23.79 (3) for (I), 24.60 (4) for (II), 33.72 (4) for (III), 29.93 (8) for (IV) and 21.81 (7)° for (V). Key features of the packing include pairwise C-H⋯O hydrogen bonds for (II) and (IV), and pairwise C-H⋯N hydrogen bonds for (V), which generate inversion dimers in each case. The packing for (I) and (III) feature C-H⋯O hydrogen bonds, which lead to [010] and [100] chains, respectively. Weak C-H⋯π inter-actions consolidate the structures and weak aromatic π-π stacking is seen in (II) [centroid-centroid separation = 3.8414 (7) Å] and (III) [3.9475 (7) Å]. A polymorph of (I) crystallized from a different solvent has been reported previously [Dimmock et al. (1999 ▸) J. Med. Chem. 42, 1358-1366] in the same space group but with a packing motif based on inversion dimers resembling that seen in (IV) in the present study. The Hirshfeld surfaces and fingerprint plots for (I) and its polymorph are com-pared and structural features of the 2-benzyl-idene-1-benzosuberone family of phases are surveyed.

Synthesis and Magnetic Properties of a Copper Cube: [Cu4(OH)4(C16H18N2)4]4+ (ClO4)4 C3H6O [C16H18N2=(E)-1,6-[Di(pyridin-4-yl)hex-3-ene].

The synthesis of a Cu4(OH)4 cube which is coordinated by four molecules of the dipyridyl ligand 1,6-[di(pyridin-4-yl)hex-3-ene] is reported. This compound has a trans double bond which restricts the conformational freedom of the ligand and favours coordination within a unique copper cube. The structure was solved by an X-Ray single crystal structure determination and low temperature magnetic susceptibility measurements examined its magnetic properties. The cube classification corresponds to the type I classification of Mergehenn and Haase and the short/long distribution of Cu ⋅⋅⋅ Cu separations in the cube as defined by Ruiz. The magnetic susceptibility measurements show paramagnetic behaviour down to 50 K but below this the copper cube shows weak ferromagnetic exchange interactions. The low temperature magnetic susceptibility characteristics are examined in detail then modelled and compared to other similar Cu4O4 copper cubes.