(μ2-2-Methoxyethanol-κ3O1:O1,O3)(2-methoxyethanol-κO1)tris(μ2-3,4,5,6-tetrafluoro-o-phenylene-κ2C1:C2)trimercury(II)

In the title compound, [Hg3(C6F4)3(C3H8O2)2], two O atoms from one 2-methoxyethanol ligand and one O atom from the second 2-methoxyethanol ligand coordinate three HgII atoms [Hg—O = 2.765 (7)–2.890 (8) Å] in the trimeric organomercurial Lewis acid (o-C6F4Hg)3. The hydroxy groups are involved in formation of intra- and intermolecular O—H...O hydrogen bonds; the latter link two molecules into centrosymmetric dimers. An extensive net of weak intermolecular C—H...F interactions further consolidates the crystal packing

New Acentric Materials Constructed From Aminopyridines And 4-Nitrophenol

Co-crystallization of 4-nitrophenol (I) with five aminopyridines (4-aminopyridine 1, 3,4-diaminopyridine 2, 2,3-diaminopyridine 3, 3-aminopyridine 4, 2-amino-6-methylpyridine 5) and 2,4-diaminopyrimidine 6 resulted in six adducts with the ratio of components 2 : 1 in five and 1 : 1 in one final compounds. Single crystals were grown by slow evaporation technique using ethanol as a solvent. Five adducts with 1-5 crystallize in acentric P21 and Pna21 space groups, and one, 2(I)·6-in centrosymmetric P21/c space group. Compounds 2(I)·1, 2(I)·2, 2(I)·3 are isomorphous, and demonstrate similar H-bonding patterns despite the differences in aminopyridine molecules. Compound 2(I)·5 is isomorphous to two previously reported compounds. Adducts 2(I)·1, 2(I)·2, 2(I)·3, 2(I)·5, 2(I)·6 represent organic salts composed of pyridinium/pyrimidinium cation, 4-nitrophenolate anion, and 4-nitrophenol neutral molecule. The H-bonded 4-nitrophenol-4-nitrophenolate anionic dimers were found in all compounds with 2 : 1 molar ratio. In adduct I·4 both molecules are in neutral form. The IR spectral data support crystallographic conclusions on salts formation. Plane wave pseudopotential density functional theory calculations were used to predict hyperpolarizability tensor components. Our calculations suggest 2(I)·3 as the best candidate for nonlinear optical materials (14 times more active than urea). © 2013 The Royal Society of Chemistry

6-Methylpyridin-2-amine

In the title molecule, C6H8N2, the endocyclic angles are in the range 118.43 (9)–122.65 (10)°. The molecular skeleton is planar (r.m.s. deviation = 0.007 Å). One of the two amino H atoms is involved in an N—H...N hydrogen bond, forming an inversion dimer, while the other amino H atom participates in N—H...π interactions between the dimers, forming layers parallel to (100)

Crystal structure of 8-hydroxyquinoline: a new monoclinic polymorph

In an attempt to grow 8-hydroxyquinoline–acetaminophen co-crystals from equimolar amounts of conformers in a chloroform–ethanol solvent mixture at room temperature, the title compound, C9H7NO, was obtained. The molecule is planar, with the hydroxy H atom forming an intramolecular O—H...N hydrogen bond. In the crystal, molecules form centrosymmetric dimers via two O—H...N hydrogen bonds. Thus, the hydroxy H atoms are involved in bifurcated O—H...N hydrogen bonds, leading to the formation of a central planar four-membered N2H2 ring. The dimers are bound by intermolecular π–π stacking [the shortest C...C distance is 3.2997 (17) Å] and C—H...π interactions into a three-dimensional framework. The crystal grown represents a new monoclinic polymorph in the space group P21/n. The molecular structure of the present monoclinic polymorph is very similar to that of the orthorhombic polymorph (space group Fdd2) studied previously [Roychowdhury et al. (1978). Acta Cryst. B34, 1047–1048; Banerjee & Saha (1986). Acta Cryst. C42, 1408–1411]. The structures of the two polymorphs are distinguished by the different geometries of the hydrogen-bonded dimers, which in the crystal of the orthorhombic polymorph possess twofold axis symmetry, with the central N2H2 ring adopting a butterfly conformation

Pyrimidine-2,4-diamine acetone monosolvate

In the title compound, C4H6N4·C3H6O, the pyrimidine-2,4-diamine molecule is nearly planar (r.m.s. deviation = 0.005 Å), with the endocyclic angles covering the range 114.36 (10)–126.31 (10)°. In the crystal, N—H...N and N—H...O hydrogen bonds link the molecules into ribbons along [101], and weak C—H...π interactions consolidate further the crystal packing

Pyridine-2,5-diamine

In the title molecule, C5H7N3, intracyclic angles cover the range 117.15 (10)–124.03 (11)°. The N atoms of the amino groups have trigonal–pyramidal configurations deviating slightly from the pyridine plane by 0.106 (2) and −0.042 (2) Å. In the crystal, the pyridine N atom serves as an acceptor of an N—H...N hydrogen bond which links two molecules into a centrosymmetric dimer. Intermolecular N—H...N hydrogen bonds between the amino groups further consolidate the crystal packing, forming a three-dimensional network

Unusual Chemical Ratio, Z″ Values, and Polymorphism in Three New <i>N-</i>Methyl Aminopyridine–4-Nitrophenol Adducts

Cocrystallization of 4-nitrophenol (<b>I</b>) with <i>N</i>-methyl substituted aminopyridines, 4-<i>N</i>-methylaminopyridine <b>1</b>, 2-<i>N</i>-methylaminopyridine <b>2</b>, and 2-<i><i>N,N</i></i>-dimethylaminopyridine <b>3</b>, resulted in three novel adducts <b>1</b>·2­(<b>I</b>), <b>2</b>·3­(<b>I</b>), and <b>3</b>·3­(<b>I</b>), one of which, <b>2</b>·3­(<b>I</b>), was found in three polymorphic forms, <b>A</b>, <b>B</b>, and <b>C</b>. The single crystals were grown by slow evaporation from ethanol. The proton transfer from the phenoxy to the pyridine moieties was registered in all compounds. The adducts comprise pyridinium cations, 4-nitrophenolate anions, and varying in number neutral 4-nitrophenol molecules. Though the asymmetric hydrogen-bonded network involving the −N⁺H groups of pyridinium cations and the −C–O^– and −C–OH groups of 4-nitrophenol moieties is registered in the adducts, the delicate balance of noncovalent interactions that include CH···O hydrogen bonds and face-to-face stacking interactions between the extended antiparallel arrays of components controls the centrosymmetric packing. Although three polymorphs of <b>2</b>·3­(<b>I</b>) share several structural common features, they reveal significant differences in the conformation of the pyridinium cation, and the hydrogen-bonding patterns