Crystal structure and Hirshfeld surface analysis of 3-cyano-phenyl-boronic acid.

In the title compound, C7H6BNO2, the mean plane of the -B(OH)2 group is twisted by 21.28 (6)° relative to the cyano-phenyl ring mean plane. In the crystal, mol-ecules are linked by O-H⋯O and O-H⋯N hydrogen bonds, forming chains propagating along the [101] direction. Offset π-π and B⋯π stacking inter-actions link the chains, forming a three-dimensional network. Hirshfeld surface analysis shows that van der Waals inter-actions constitute a further major contribution to the inter-molecular inter-actions, with H⋯H contacts accounting for 25.8% of the surface.

Supramolecular arrangement and photophysical properties of a dinuclear cyanophenylboronic acid ester.

Boronic esters are useful building blocks for crystal engineering and the generation of supramolecular architectures, including macrocycles, cages and polymers (one-, two- and three-dimensional), with potential utility in diverse fields such as separation, storage and luminescent materials. The novel dinuclear cyanophenylboronic ester described herein, namely 4,4'-(2,4,8,10-tetraoxa-3,9-diboraspiro[5.5]undecane-3,9-diyl)dibenzonitrile, C19H16B2N2O4, was prepared by condensation of 4-cyanophenylboronic acid and pentaerythritol and fully characterized by elemental analysis, IR and NMR (1H and 11B) spectroscopy, single-crystal X-ray diffraction analysis and TG-DSC (thermogravimetry-differential scanning calorimetry) studies. In addition, the photophysical properties were examined in solution and in the solid state by UV-Vis and fluorescence spectroscopies. Density functional theory (DFT) calculations with ethanol as solvent reproduced reasonably well the HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) of the title compound. Hirshfeld surface and fingerprint plot analyses are presented to illustrate the supramolecular connectivity in the solid state.

Synthesis, crystal structure, DFT studies and photophysical properties of a copper(I)-triphenylphosphane complex based on trans-(±)-2,4,5-tris(pyridin-2-yl)-2-imidazoline.

The possibility of using less expensive and nontoxic metals, such as copper, as substitutes for more expensive heavy metals in the synthesis of new transition-metal complexes to be used as sensitizers in dye-sensitized solar cells (DSSCs) has stimulated research in this field. The novel photoluminescent copper(I) complex bis(triphenylphosphane-κP)[trans-(±)-2,4,5-tris(pyridin-2-yl)-2-imidazoline-κ2N2,N3]copper(I) hexafluorophosphate, [CuI(C18H15N5)(C18H15P)2]PF6, has been successfully synthesized and characterized by IR and 1H NMR spectroscopy, as well as by single-crystal X-ray diffraction and thermogravimetric analysis. The complex showed interesting photophysical properties, which were studied experimentally in solution and in the solid state by UV-Vis and fluorescence spectroscopy. Density functional theory (DFT) calculations with dichloromethane as solvent reproduced reasonably well the HOMO and LUMO orbitals of the title compound.

Two novel organic-inorganic hybrid materials from tetrachloridometallate(II) salts and 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium.

Two organic-inorganic hybrid compounds have been prepared by the combination of the 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium cation with perhalometallate anions to give 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium tetrachloridocobaltate(II), (C12H12N2)[CoCl4], (I), and 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium tetrachloridozincate(II), (C12H12N2)[ZnCl4], (II). The compounds have been structurally characterized by single-crystal X-ray diffraction analysis, showing the formation of a three-dimensional network through X-H...ClnM(-) (X = C, N(+); n = 1, 2; M = Co(II), Zn(II)) hydrogen-bonding interactions and π-π stacking interactions. The title compounds were also characterized by FT-IR spectroscopy and thermogravimetric analysis (TGA).

2,6-Dihy-droxy-4-oxo-2-(pyridin-1-ium-3-yl)-4H-1,3,2-benzodioxaborinin-2-ide 0.67-hydrate.

The asymmetric unit of the title compound, C12H10BNO5·0.67H2O, contains three independent pyridinylboronic acid esters adopting zwitterionic forms and two water mol-ecules. The six-membered heterocyclic rings in the boronic esters have half-chair conformations and the deviations of the B atoms from the boronate mean planes range from 0.456 (3) to 0.657 (3) Å. All of the B atoms have tetra-hedral coordination environments, with B-O and B-C bond lengths of 1.446 (4)-1.539 (3) and 1.590 (5)-1.609 (5) Å, respectively. In the crystal, the ester and water mol-ecules are linked into a three-dimensional network by a large number of O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds. The crystal packing is further accomplished by π-π inter-actions, with centroid-centroid distances of 3.621 (4)-3.787 (4) Å.

Benzene-1,3,5-tri-carb-oxy-lic acid-pyridinium-2-olate (1/3).

The asymmetric unit of the title compound, C9H6O6·3C5H5NO, contains one benzene-1,3,5-tri-carb-oxy-lic acid mol-ecule (BTA) and three pyridin-2-ol mol-ecules each present in the zwitterion form. In the crystal, these entities are linked through O-H⋯O(-) and N(+)-H⋯O(-) hydrogen bonds, forming sheets parallel to (10-1). These layers contain macrocyclic rings of composition [BTA]2[pyol]6 and with graph-set notation R (6) 8(44), which are stacked along c through π-π inter-actions [inter-centroid distances = 3.536 (2)-3.948 (3) Å]. They are inter-connected by N(+)-H⋯O(-) hydrogen-bonded chains of pyridin-2-ol mol-ecules running parallel to c, forming a three-dimensional network. There are also C-H⋯O hydrogen bonds present which reinforce the three-dimensional structure.

Bis{2-[2,5-bis-(pyridin-2-yl)-1H-imidazol-4-yl]pyridinium} tetra-cyanidoplatinate(II) tetra-hydrate.

The asymmetric unit of the title hydrated complex salt, (C18H14N5)2[Pt(CN)4]·4H2O, consists of one 2-[2,5-bis-(pyridin-2-yl)-1H-imidazol-4-yl]pyridinium cation, half a tetra-cyanidoplatinate(II) dianion, which is located about a crystallographic inversion center, and two water mol-ecules of crystallization. The Pt(II) atom has a square-planar coordination environment, with Pt-CCN distances of 1.992 (4) and 2.000 (4) Å. In the cation, there is an N-H⋯N hydrogen bond linking adjacent pyridinium and pyridine rings in positions 4 and 5. Despite this, the organic component is non-planar, as shown by the dihedral angles of 10.3 (2), 6.60 (19) and 15.66 (18)° between the planes of the central imidazole ring and the pyridine/pyridinium substituents in the 2-, 4- and 5-positions. In the crystal, cations and anions are linked via O-H⋯O, O-H⋯N and N-H⋯O hydrogen bonds, forming a three-dimensional network. Additional π-π, C-H⋯O and C-H⋯N contacts provide stabilization to the crystal lattice.

Cyclo-hexane-1,4-dicarb-oxy-lic acid-pyridinium-4-olate (1/1).

In the title adduct, C5H5NO·C8H12O4, the heterocycle exists in its zwitterionic form. The cyclo-hexane ring exhibits a chair conformation with the carb-oxy-lic acid groups in equatorial and axial orientations. In the crystal, mol-ecules are linked through charge-assisted O-H⋯O(-), N(+)-H⋯O(-) and N(+)-H⋯O hydrogen bonds, and an additional series of C-H⋯O contacts, giving a pleated two-dimensional hydrogen-bonded network parallel to (-204).

Bis[(1RS,2RS)-4,4'-(1-aza-niumyl-2-hy-droxy-ethane-1,2-di-yl)dipyridinium] tris-[tetra-chloridopalladate(II)].

The asymmetric unit of the title compound, (C12H16N3O)2[PdCl4]3, consists of a 4,4'-(1-aza-niumyl-2-hy-droxy-ethane-1,2-di-yl)dipyridinium dication and one and a half tetra-chloridopalladate(II) anions; the latter has inversion symmetry. In the cation, the pyridinium rings attached to the central 1-aza-niumyl-2-hy-droxy-ethane fragment show an anti conformation, as indicated by the central C-C-C-C torsion angle of -178.1 (4)°, and they are inclined to one another by 25.7 (2)°. In the crystal, the cations and anions are linked through N-H⋯Cl and O-H⋯Cl hydrogen bonds. There are also π-π contacts [centroid-centroid distance = 3.788 (3) Å] and a number of C-H⋯O and C-H⋯Cl inter-actions are present, consolidating the formation of a three-dimensional structure.

(1RS,2RS)-4,4'-(1-Aza-niumyl-2-hy-droxy-ethane-1,2-di-yl)dipyridinium tetra-chlorido-platinate(II) chloride.

The title compound, (C12H16N3O)[PtCl4]Cl, consists of a 4,4'-(1-aza-niumyl-2-hy-droxy-ethane-1,2-di-yl)dipyridinium trication, a square-planar tetra-chloridoplatinate(II) dianion and a chloride ion. In the cation, the pyridinium rings attached to the central 1-aza-niumyl-2-hy-droxy-ethane fragment have an anti conformation, as indicated by the central C-C-C-C torsion angle of -166.5 (6)°, and they are inclined to one another by 63.5 (4)°. In the crystal, the cations and anions are linked through N-H⋯Cl and O-H⋯Cl hydrogen bonds. There are also π-π contacts [centroid-centroid distances = 3.671 (4) and 3.851 (4) Å] and a number of C-H⋯Cl inter-actions present, consolidating the formation of a three-dimensional supra-molecular structure.

Dichloridobis(methanol-κO)[cis-(±)-2,4,5-tris-(pyridin-2-yl)-2-imidazoline-κ(3)N(2),N(3),N(4)]ytterbium(III) chloride.

In the crystal structure of the title complex, [YbCl(2)(C(18)H(15)N(5))(CH(3)OH)(2)]Cl, the pseudo-penta-gonal-bipyramidal coordination geometry of the Yb(III) cation is composed of three N atoms from one cis-(±)-2,4,5-tris-(pyridin-2-yl)imidazoline (HL) ligand, two O atoms from two methanol mol-ecules and two Cl(-) anions. Chains are formed along [010] through N-H⋯Cl, O-H⋯Cl and O-H⋯N hydrogen bonds.

3-Amino-pyridin-1-ium 3-carb-oxy-benzo-ate.

In the title organic salt, C(5)H(7)N(2) (+)·C(8)H(5)O(4) (-), the carb-oxy-lic group is nearly coplanar with the benzene ring [dihedral angle 1.9 (4)°] whereas the carboxyl-ate group is twisted relative to the benzene ring by 13.6 (4)°. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds connect the components into a three-dimensional framework consisting of stacks of alternating pairs of anions and cations exhibiting π-π stacking inter-actions with centroid-centroid distances in the range 3.676 (2)-3.711 (1) Å. The π-π stacks extend along [110] and [-110].

2-(3-Amino-pyridinium-1-yl)-3-carb-oxy-propano-ate monohydrate.

The title compound, C(9)H(10)N(2)O(4)·H(2)O, was obtained as a zwitterion derived from the nucleophilic attack of 3-amino-pyridine on the fumaric α,ß-system. Within the molecule, the amino-pyridine moiety and the carboxyl-ate and carb-oxy-lic acid fragments form dihedral angles of 68.6 (2) and 62.8 (2)°, respectively. The geometry adopted by the mol-ecule does not allow the formation of centrosymmetric dimeric hydrogen-bonded units; instead chains along the a axis are linked by COO-H⋯OOC motifs. These chains are inter-connected by N-H⋯O and O-H⋯O hydrogen bonds involving the carb-oxy-lic acid and carboxyl-ate units and the solvent water mol-ecules.

4-[(E)-2-(Pyridin-2-yl)ethen-yl]pyridine-terephthalic acid (2/1).

The title 2:1 co-crystal, 2C12H10N2·C8H6O4, crystallizes with one mol-ecule of 4-[(E)-2-(pyridin-2-yl)ethen-yl]pyridine (A) and one half-mol-ecule of terephthalic acid (B) in the asymmetric unit. In the crystal, the components are linked through heterodimeric COOH⋯Npyridine synthons, forming linear aggregates of composition -A-B-A-B-. Further linkage through weak C-H⋯O and C-H⋯π inter-actions gives two-dimensional hydrogen-bonded undulating sheets propagating in the [100] and [010] directions. These layers are connected through additional weak C-H⋯O contacts, forming a three-dimensional structure.

Tetra-kis(µ-acetato-κ(2)O:O')-bis-[(3-pyridine-carboxaldehyde-κN')]dicopper(II)(Cu-Cu).

The binuclear title compound, [Cu(2)(CH(3)CO(2))(4)(C(6)H(5)NO)], is located about a center of inversion. The Cu(II) atoms are connected [Cu-Cu = 2.6134 (5) Å] and bridged by four acetate ligands. Their distorted octa-hedral coordination geometry is completed by a terminal pyridine N atom of a 3-pyridincarboxaldehyde ligand. In the crystal, the complex mol-ecules are linked by C-H⋯O hydrogen bonds, forming two-dimensional networks lying parallel to the ab plane. These networks are linked via C-H⋯O hydrogen bonds involving inversion-related 3-pyridinecarboxaldehyde ligands, forming a three dimensional supra-molecular architecture.