N,N′-Bis(6-methyl-2-pyrid­yl)oxamide

In the crystal structure of the title compound, C14H14N4O2, the mol­ecules are almost planar (mean deviation 0.028 Å) and a weak intra­molecular N—H⋯O hydrogen bond between the H atom bound to an oxamide N atom and a carbonyl O atom is found. The asymmetric unit consits of one half-mol­ecule which is located on a centre of inversion

N,N′-Bis(pyridin-2-yl)benzene-1,4-dicarboxamide

Mol­ecules of the title compound, C18H14N4O2, are located around an inversion center and connected into chains in the crystal via inter­molecular N—H⋯N hydrogen bonds generating an R 2 2(8) motif

Methyl 4-[(5-chloro­pyrimidin-2-yl)carbamo­yl]benzoate

Mol­ecules of the title compound, C13H10ClN3O3, form centrosymmetric dimers via inter­molecular N—H⋯N hydrogen bonds generating an R 2 2(8) motif. The dimers are further connected through an O⋯Cl—C halogen bond [O⋯Cl = 3.233 (1) Å and O⋯Cl—C = 167.33 (1)°] into a chain along [110]. The secondary amide group adopts a cis conformation. Weak C—H⋯N hydrogen bonds among the methyl benzoate and pyrimidyl rings are also observed in the crystal structure

5-Iodo­pyrimidin-2-amine

The mol­ecule of the title compound, C4H4IN3, has crystallographic mirror plane symmetry. In the crystal, the mol­ecules are connected through N—H⋯N hydrogen bonds into polymeric tapes extended along the a axis, which are typical of 2-amino­pyrimidines. Each mol­ecule acts as a double donor and a double acceptor in the hydrogen bonding

6,6′-Dimethyl-2,2′-[oxalylbis(aza­nedi­yl)]dipyridinium dichloride acetonitrile solvate

In the crystal structure of the title compound, C14H16N4O2 2+·2Cl−·CH3CN, weak inter­molecular N—H⋯Cl hydrogen bonds are found between the H atoms bound to the pyridine and amine N atoms and the chloride anions. The asymmetric unit consits of one half cationic mol­ecule which is located on a centre of inversion, one chloride anion in a general position and one half acetonitrile mol­ecule which is located on a twofold axis. Because of symmetry, the C—H hydrogens of the acetonitrile solvent mol­ecule are disordered over two orientations

2-{5-[N-(2-Pyridyl)carbamo­yl]pentan­amido}pyridinium hexa­fluoro­phosphate

In the crystal structure of the title compound, C16H19N4O2 +·PF6 −, the cations and anions are situated on centres of inversion. Thus, the N—H H atom is disordered over both N atoms due to symmetry. In the crystal, mol­ecules are connected via N—H⋯F and N—H⋯O hydrogen bonds. The cation adopts the ⋯AAA⋯ trans conformation in the solid state

N 1,N 2-Bis(6-methyl-2-pyrid­yl)formamidine

In the crystal structure of the title mol­ecule, C13H14N4, the two pyridyl rings are not coplanar but twisted about the C—N bond with an inter­planar angle of 71.1 (1)°. In the crystal, the mol­ecules form dimers, situated on crystallographic centres of inversion, which are connected via a pair of N—H⋯N hydrogen bonds. C—H⋯π-electron ring inter­actions are also present in the crystal structure. The title mol­ecule adopts an s–cis–anti–s–cis conformation in the solid state

N-(6-Methyl-2-pyrid­yl)formamide

The mol­ecule of the title compound, C7H8N2O, is essentially planar with a maximum deviation of 0.0439 (1) Å from the best plane. In the crystal, N—H⋯O hydrogen bonds between self-complementary amide groups join mol­ecules into centrosymmetric dimers

Bis(4,4′-methyl­enedicyclo­hexyl­aminium) μ-benzene-1,4-dicarboxyl­ato-bis­[tri­chlorido­zinc(II)] tetra­hydrate

The title compound, (C13H28N2)2[Zn2(C8H4O4)Cl6]·4H2O, was prepared by the reaction of ZnCl2·6H2O, benzene-1,4-dicarboxylic acid and 4,4′-diamino­dicyclo­hexyl­methane in methanol. The [Zn2Cl6(C8H4O4)]4− anions lie on centres of inversion and comprise two ZnCl3 groups bridged by benzene-1,4-dicarboxyl­ate. In addition to N—H⋯Cl and N—H⋯O hydrogen bonds between the cations and anions, solvent water mol­ecules form O—H⋯O and O—H⋯Cl hydrogen bonds to give a three-dimensional network

Methyl (2′S,3′S)-3,4-O-(2′,3′-dimethoxy­butane-2′,3′-di­yl)-α-l-rhamnopyran­oside: a glycosyl acceptor

The title compound, C13H24O7, is the product of the ketalization of methyl l-(+)-rhamnopyran­oside with 2,3-butane­dione. It crystallizes with two mol­ecules in the asymmetric unit, which are connected by O—H⋯O hydrogen bonds. The C-3,4 diequatorial hydroxy groups of the methyl l-(+)-rhamnopyran­oside were protected, leaving the C-2 hydroxy group free. The l-(+)-rhamnopyran­oside and 2′,3′-dimethoxy­butane-2′,3′-diyl rings adopt chair conformations and all meth­oxy groups are in axial positions. The absolute configuration was assumed from the synthesis