Crystal structure of bis[2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole-κ2N2,N3]bis(thiocyanato-κS)copper(II)

The mononuclear title complex, [Cu(SCN)2(C12H8N4S)2], was obtained by the reaction of 2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole and potassium thiocyanate with copper(II) chloride dihydrate. The copper cation lies on an inversion centre and displays an elongated octahedral coordination geometry. The equatorial positions are occupied by the N atoms of two 2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole ligands, whereas the axial positions are occupied by the S atoms of two thiocyanate anions. The thiadiazole and the pyridyl rings linked to the metal are approximately coplanar, with a maximum deviation from the mean plane of 0.190 (2) Å. The cohesion of the crystal structure is ensured by weak C—H...N hydrogen bonds and π–π interactions between parallel pyridyl rings of neighbouring molecules [centroid-to-centroid distance = 3.663 (2) Å], leading to a three-dimensional network

Crystal structure of bis(azido-κN)bis[2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole-κ2N2,N3]nickel(II)

Reaction of 2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole and sodium azide with nickel(II) triflate yielded the mononuclear title complex, [Ni(N3)2(C12H8N4S)2]. The NiII ion is located on a centre of symmetry and is octahedrally coordinated by four N atoms of the two bidentate heterocyclic ligands in the equatorial plane. The axial positions are occupied by the N atoms of two almost linear azide ions [N—N—N = 178.8 (2)°]. The thiadiazole and pyridine rings of the heterocyclic ligand are almost coplanar, with a maximum deviation from the mean plane of 0.0802 (9) Å. The cohesion of the crystal structure is ensured by π–π interactions between parallel pyridine rings of neighbouring molecules [centroid-to-centroid distance = 3.6413 (14) Å], leading to a layered arrangement of the molecules parallel to (001)

2-[5-(Pyridin-2-yl)-1,3,4-thiadiazol-2-yl]pyridin-1-ium perchlorate

The cation of the title molecular salt, C12H9N4S+·ClO4−, is approximately planar, with the pyridine and pyridinium rings being inclined to the central thiadiazole ring by 6.51 (9) and 9.13 (9)°, respectively. The dihedral angle between the pyridine and pyridinium rings is 12.91 (10)°. In the crystal, the cations are linked by N—H...O and C—H...O hydrogen bonds, involving the perchlorate anion, forming chains propagating along the [100] direction. The chains are linked by weak offset π–π interactions [inter-centroid distance = 3.586 (1) Å], forming layers parallel to the ab plane

Crystal structure of (Z)-ethyl 3-[2-(5-methyl-7-nitro-1H-indole-2-carbonyl)hydrazinylidene]butanoate

The reaction of 5-methyl-7-nitro-1H-indole-2-carbohydrazide with ethyl acetoacetate yielded the title molecule, C16H18N4O5, in which the indole ring is almost planar, with the greatest deviation from the mean plane being 0.006 (2) Å. The nine atoms of the indole ring are almost perpendicular to the mean plane through the ethyl acetate group, as indicated by the dihedral angle of 87.02 (4)° between them. In the crystal, centrosymmetric supramolecular dimers are formed via N—H...O hydrogen bonds and eight-membered amide {...HNCO}2 synthons. These are consolidated into a three-dimensional architecture by C—H...O contacts, and by π–π interactions between six-membered rings [inter-centroid distance = 3.499 (2) Å]

Bis[μ-2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole-κ4N2,N3:N4,N5]bis[(nitrato-κO)silver(I)] tetrahydrate

The self-assembly of an angular 2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole ligand (L) with silver nitrate (AgNO3) produced a new dinuclear silver(I) coordination complex, [Ag2(C12H8N4S)2(NO3)2]·4H2O, which crystallizes with two Ag atoms bridged by two L ligands. The Ag atom is surrounded by four N atoms of L and by one O from the nitrate anion defining a distorted square pyramid. The atoms comprising the dication are nearly coplanar, with an r.m.s. deviation of 0.1997 Å. Molecules are linked by C—H...O and O—H...O hydrogen bonds through nitrate anions and water molecules, forming a two-dimensional porous network. The overall structure involves stacking of Ag complex layers along the b axis. The cohesion in the three-dimensional architecture is ensured by O...Ag interactions

Ethyl 2-[(Z)-2-(2-nitrophenyl)hydrazinylidene]propanoate

In the molecule of the title compound, C11H13N3O4, all non-H atoms are nearly coplanar with the largest deviation from the mean plane being 0.152 (2) Å. A strong intramolecular N—H...O hydrogen bond closes a six-membered ring. In the crystal, molecules are linked by π–π interactions [intercentroid distance = 3.724 (2) Å], forming stacks parallel to the c axis

Synthesis of new (pyrazol-1-yl)(7-nitro-1h-indol-2-yl)ketone derivatives

International audienceThe condensation of 7-nitroindole-2-carbohydrazide derivatives with acetylacetone lead to (pyrazol-1-yl)(7-nitroindol-2-yl)ketones

Novel CuI coordination polymer self-assembled from 2,5-bis(pyridin-4-yl)-1,3,4-oxadiazole and thiocyanate ions: Synthesis, structural characterization, Hirshfeld surface analysis, thermal and magnetic studies

International audienceThe synthesis and crystal structure of one-dimensional (1-D) coordination polymer from an angular dipyridyl ligand 2,5-bis(pyridine-4-yl)-1,3,4-oxadiazole (4-pox) and CuCl 2 2H 2 O, [Cu I (4-poxH)(SCN)(μ 1,3-SCN)] n (named complex 1), are reported. The investigated copper(I) complex crystallizes in the monoclinic crystal system with space group P 2 1 / n. UV-vis and FTIR suggest the co-presence of the 4-pox ligand and the pseudohalide, in the isolated complex. This was confirmed by a crystallographic study which shows that the copper is in a tetrahedral environment, linked to two thiocyanate groups and to two nitrogen atoms, one belonging to the pyridine ring and the others to thiocyanate group. The crystallographic study also reveals the protonation of the unbound organic ligand pyridine. The crystal cohesion is assured by different intermolecular hydrogen bonds, π-π stacking, and coordination bonds (N-Cu and S-Cu). Therefore, the one-dimensional coordination chains are further interconnected by hydrogen bonds and π-π stacking to from a three-dimensional supramolecular framework. This behaviour was confirmed by Hirshfeld surface analysis. The thermal analysis reveals that complex 1 is thermally stable up to 160 °C. The magnetic measurements indicated the diamagnetic nature of this Cu I coordination polymer

Mechanistic Insights into the Selective Synthesis of 4H-Pyran Derivatives On-Water Using Naturally Occurring Alginate from Sargassum muticum: Experimental and DFT Study

The naturally occurring sodium alginate (SA) biopolymer from the Sargassum muticum (Yendo) Fensholt was employed as a green organocatalyst for the synthesis of 4H-pyran derivatives. The naturally extracted macromolecule was fully characterized using different analyses, including nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Energy Dispersive X-ray Analysis (EDX). The catalytic activity of SA was investigated in the one-pot reaction between aldehydes, malononitrile, and 1,3-dicarbonyl compounds in water at room temperature, and the corresponding 2-amino-3-cyano-4H-pyran derivatives were obtained with good to excellent yields. This organocatalyst was easily separated from the reaction mixture and reused for at least two consecutive cycles without a significant loss of its catalytic activity or selectivity. From the mechanistic point of view, density functional theory (DFT) and NCI analyses were performed for the first time to explain the regioselectivity outcomes for the synthesis of 2-amino-3-cyano-4H-pyran derivatives using SA as a green organocatalyst