Search results for "Pyridine"
showing 10 items of 2516 documents
A reversible hydrogen‐bond isomerization triggered by an abrupt spin crossover near room temperature.
2020
The spin crossover salt [Fe(bpp) 2 ](isonicNO) 2 ·2.4H 2 O ( 1 ·2.4H 2 O) (bpp = 2,6‐bis(pyrazol‐3‐yl)pyridine; isonicNO = isonicotinate N‐oxide anion) exhibits a very abrupt spin crossover at T 1 /2 = 274.4 K. This triggers a supramolecular linkage (H‐bond) isomerization that responds reversibly towards light irradiation or temperature change. Isotopic effects in the thermomagnetic behaviour reveal the importance of hydrogen bonds in defining the magnetic state. Further, the title compound can be reversibly dehydrated to afford 1 , a material that also exhibits spin crossover coupled to H‐bond isomerization, leading to strong kinetic effects in the thermomagnetic properties.
Ethyl 5-amino-3-(pyridin-4-yl)-1-(2,4,6-trichlorophenyl)-1H-pyrazole-4-carboxylate dimethyl sulfoxide hemisolvate
2012
The asymmetric unit of the title compound, C17H13Cl3N4O2·0.5C2H6OS, contains two almost identical molecules and one dimethyl sulfoxide (DMSO-d6) solvent molecule. The pyrazole ring forms dihedral angles of 54.6 (4) and 80.0 (4)° in one molecule, and dihedral angles of 54.2 (4) and 81.2 (4)° in the other molecule, with the directly attached pyridine and trichlorophenyl rings, respectively. The dihedral angles of the pyridine and trichlorophenyl rings are 51.2 (4) and 52.0 (4)°, respectively. The crystal packing is characterized by intra- and intermolecular hydrogen bonds. The crystal is a nonmeroh…
4-[2-(4-Fluorophenyl)furan-3-yl]pyridine
2009
In the crystal structure of the title compound, C(15)H(10)FNO, the furan ring makes dihedral angles of 40.04 (11) and 25.71 (11)° with the pyridine and 4-fluoro-phenyl rings, respectively. The pyridine ring makes a dihedral angle of 49.51 (10)° with the 4-fluoro-phenyl ring. Non-conventional C-H⋯F and C-H⋯N hydrogen bonds are effective in the stabilization of the crystal structure.
5-(4-Fluoro-phen-yl)-4-(4-pyrid-yl)-1,3-oxazol-2-amine.
2010
In the crystal structure of the title compound, C14H10FN3O, the plane of the isoxazole ring makes dihedral angles of 35.72 (9) and 30.00 (9)°, respectively, with those of the 4-fluorophenyl and pyridine rings. The plane of the 4-fluorophenyl ring makes a dihedral angle of 45.85 (8)° with that of the pyridine ring. The crystal structure is stabilized by intermolecular N—H...N hydrogen bonding. The two types of hydrogen bonds result in two chains, extending along the a axis, which are related by centres of symmetry.
N-{4-[3-(4-Fluorophenyl)pyrido[2,3-b]pyrazin-2-yl]-2-pyridyl}isopropylamine
2009
In the crystal structure of the title compound, C21H18FN5, the pyridopyrazine ring system forms dihedral angles of 33.27 (7) and 48.69 (9)° with the 4-fluorophenyl and pyridine ring, respectively. The dihedral angle of the 4-fluorophenyl and pyridine rings is 57.45 (8)°. The crystal packing is characterized by an intermolecular N—H...N hydrogen bond.
4-[2-(4-Fluorophenyl)-1H-pyrrol-3-yl]pyridine
2009
In the crystal structure of the title compound, C(15)H(11)FN(2), the pyrrole ring makes dihedral angles of 33.19 (9) and 36.33 (10)° with the pyridine and 4-fluoro-phenyl rings, respectively. The pyridine ring makes a dihedral angle of 46.59 (9)° with the 4-fluoro-phenyl ring. In the crystal structure, an N-H⋯N hydrogen bond joins the mol-ecules into chains.
4-[5-(4-Fluorophenyl)-1H-imidazol-4-yl]pyridine
2009
In the title compound, C(14)H(10)FN(3), the imidazole ring makes dihedral angles of 28.2 (1) and 36.60 (9)° with the pyridine ring and the 4-fluoro-phenyl ring, respectively. The pyridine ring forms a dihedral angle of 44.68 (9)° with the 4-fluoro-phenyl ring. Inter-molecular N-H⋯N hydrogen bonds are observed in the crystal structure.
4-(4-Fluorophenyl)-3-(pyridin-4-yl)-1-(2,4,6-trichlorophenyl)-1H-pyrazol-5-amine
2012
In the title compound, C20H12Cl3FN4, the pyrazole ring forms dihedral angles of 47.51 (9), 47.37 (9) and 74.37 (9)° with the directly attached 4-fluorophenyl, pyridine and 2,4,6-trichlorophenyl rings, respectively. Only one of the two amino H atoms is involved in hydrogen bonding. The crystal packing is characterized by N—H...N hydrogen bonds, which result in infinite chains parallel to the c axis.
4-(4-Fluorophenyl)-1-phenyl-3-(pyridin-4-yl)-1H-pyrazol-5-amine
2012
In the title compound, C20H15FN4, the pyrazole ring forms dihedral angles of 43.51 (6), 39.95 (6) and 32.23 (6)° with the directly attached 4-fluorophenyl, pyridine and phenyl rings, respectively. The crystal packing is stabilized by intermolecular N—H...N and N—H...F hydrogen bonds.
Nitrate Encapsulation within the Cavity of Polyazapyridinophane. Considerations on Nitrate−Pyridine Interactions
2010
Interaction of nitrate anions with a cyclophane (L) containing two pyridine units connected to two diethylenetriamine bridges through methylene positions is reported both in pure water and in the solid state. The crystal structure of [H4L](NO3)4 shows that one of the nitrate anions resides in the macrocyclic cavity forming two sets of bifurcated hydrogen bonds with the four protonated amino groups of the macrocycle. This anion is symmetrically placed in the middle of the pyridine rings with distances between its nitrogen atom and the centroids of the ring of 3.58 A. Despite this location, calculations by theoretical analysis were carried out to confirm whether the stabilizing effect is due …