Chlorido{4-cyclo­hexyl-1-[1-(pyridin-2-yl-κN)ethyl­idene]thio­semicarbazidato-κ2 N 1,S}diphenyl­tin(IV)

The distorted octa­hedral geometry about the SnIV atom in the title compound, [Sn(C6H5)2(C14H19N4S)Cl], is defined by the N,N,S-tridentate Schiff base ligand, two mutually trans ipso-C atoms of the Sn-bound phenyl groups, and the Cl atom which is trans to the azo N atom. The two five-membered chelate rings and pyridyl ring are almost coplanar with the dihedral angle between the outer five-membered chelate and pyridine rings being 5.39 (8)°. Centrosymmetric dimers feature in the crystal packing mediated by N—H⋯S hydrogen bonds, leading to eight-membered {⋯HNCS}2 synthons. The dimeric aggregates are connected into a three-dimensional architecture by C—H⋯Cl and C—H⋯π inter­actions, as well as π–π inter­actions occurring between centrosymmetrically related pyridine rings [centroid–centroid distance = 3.6322 (13) Å]

Dichlorido{4-cyclo­hexyl-1-[1-(2-pyridyl-κN)ethyl­idene]thio­semicarbazidato-κ2 N 1,S}phenyl­tin(IV)

The SnIV atom in the title compound, [Sn(C6H5)(C14H19N4S)Cl2], exists within a distorted octa­hedral geometry defined by the N,N′,S-tridentate monodeprotonated Schiff base ligand, two mutually trans Cl atoms, and the ipso-C atom of the Sn-bound phenyl group; the latter is trans to the azo-N atom. The greatest distortion from the ideal geometry is found in the nominally trans angle formed by the S and pyridyl-N atoms at Sn [151.03 (4)°]. With the exception of the cyclo­hexyl group (chair form), the Schiff base ligand is almost planar (r.m.s. deviation of non-H and Sn atoms = 0.053 Å). The nearly orthogonal orientation of the Sn-bound phenyl group [N—Sn—C—C torsion angle = 70.8 (5)°] to the planar portion of the Schiff base allows for the formation of significant intra­molecular C—H⋯Cl inter­actions which preclude the Cl atoms from participating in N—H⋯Cl hydrogen bonds. Instead, C—H⋯π contacts, involving methyl­ene H and the Sn-bound phenyl group, lead to the formation of supra­molecular chains that pack in the bc plane. Connections between these layers are of the type C—H⋯Cl

(2E)-2-[2-(Cyclo­hexyl­carbamothio­yl)hydrazinylidene]­propanoic acid

In the title thio­urea derivative, C10H17N3O2S, the carboxyl group and the least-squares plane through the cyclo­hexyl ring are twisted out of the plane through the central CN3S residue; the respective dihedral angles are 7.18 (8) and 62.29 (4)°. The conformation about the azomethine bond [1.275 (2) Å] is E. The NH groups are anti, with one forming an intra­molecular N—H⋯N hydrogen bond. The main feature of the crystal structure is the formation of linear supra­molecular chains along [110] mediated by alternating pairs of O—H⋯O and pairs of N—H⋯S hydrogen bonds

Adsorption of Congo Red Dye from Aqueous Solution using ZnO and Al2O3/ZnO Composite: Isotherm, Kinetic and Thermodynamic Data

Herein, an adsorption study of congo red (CR) dye onto ZnO and Al2O3/ZnO  is reported. ZnO was prepared using conventional chemicals by co-precipitation method and Al2O3 used in the composite was prepared through recycling of aluminium waste. Information about the materials was obtained through spectroscopic techniques. A batch adsorption method was used to obtain the adsorption data from which isotherm, kinetic and thermodynamic parameters were obtained. The result of the adsorbents characterisation revealed the expected properties of the prepared materials. The adsorption capacities at 250 mg/L of CR dye were 24.33 mg/g and 24.57 mg/g for ZnO and Al2O3/ZnO respectively. The isotherm study of the adsorption process revealed that Langmuir model fitted best the adsorption data with monolayer adsorption capacities (qm) of 27.67 mg/g and 33.39 mg/g for ZnO and Al2O3/ZnO respectively. The adsorption was rapid within the first 15 min and the equilibrium was reached at 45 min. The kinetic study followed a pseudo-second-order model with the rate constant of 0.049 and 0.093 g.mg-1.min-1 for ZnO and Al2O3/ZnO  respectively. Experimentally, the process was endothermic and was supported by the positive values of enthalpy (ΔH) with positive values of entropy (ΔS). The change in free energy (ΔG) is negative at all temperatures studied, indicating spontaneity but more spontaneous for Al2O3/ZnO than ZnO. The adsorption of CR dye from an aqueous solution onto ZnO as an adsorbent can be slightly improved upon by the introduction of Al2O3 to form Al2O3/ZnO composite

3-{(E)-[1-(2-Hy­droxy­phen­yl)ethyl­idene]amino}-1-(2-methyl­phen­yl)thio­urea

In the title thio­urea derivative, C16H17N3OS, the hy­droxy- and methyl-substituted benzene rings form dihedral angles of 9.62 (12) and 55.69 (6)°, respectively, with the central CN3S chromophore (r.m.s. deviation = 0.0117 Å). An intra­molecular O—H⋯N hydrogen bond ensures the coplanarity of the central atoms. The H atoms of the NH groups are syn and the conformation about the N=C double bond [1.295 (4) Å] is E. In the crystal, helical supra­molecular chains sustained primarily by N—H⋯S hydrogen bonds are found. Additional stabilization is provided by C—H⋯π and π–π [ring centroid(hy­droxy­benzene)⋯ring centroid(methyl­benzene) = 3.8524 (18) Å] inter­actions

1-Cyclo­hexyl-3-{(E)-[1-(pyridin-2-yl)ethyl­idene]amino}­thio­urea

In the title thio­urea derivative, C14H20N4S, the non-ring non-H atoms are approximately planar, with an r.m.s. deviation of 0.0720 Å. The pyridine ring is twisted out of this plane and makes a dihedral angle of 16.85 (13)° with it. The mean plane passing through the cyclo­hexyl ring is almost normal to the central plane [dihedral angle = 69.23 (8)°]. An intra­molecular N—H⋯N(imine) hydrogen bond occurs. Centrosymmetric dimers are formed in the crystal structure via pairs of N—H⋯S hydrogen bonds, and these are connected into a supra­molecular chain along the a axis via C—H⋯π(pyrid­yl) inter­actions

Recent advances in cleaner hydrogen productions via thermo-catalytic decomposition of methane: Admixture with hydrocarbon

A continuous increase in the greenhouse gases concentration due to combustion of fossil fuels for energy generation in the recent decades has sparked interest among the researchers to find a quick solution to this problem. One viable solution is to use hydrogen as a clean and effective source of energy. In this paper, an extensive review has been made on the effectiveness of metallic catalyst in hydrocarbon reforming for COX free hydrogen production via different techniques. Among all metallic catalyst, Ni-based materials impregnated with various transition metals as promoters exhibited prolonged stability, high methane conversions, better thermal resistance and improved coke resistance. This review also assesses the effect of reaction temperature, gas hour space velocity and metal loading on the sustainability of thermocatalytic decomposition TCD of methane. The practice of co-feeding of methane with other hydrocarbons specifically ethylene, propylene, hydrogen sulphide, and ethanol are classified in this paper with the detailed overview of TCD reaction kinetics over an empirical model based on power law that has been presented. In addition, it is also expected that the outlook of TCD of methane for green hydrogen production will provide researchers with an excellent platform to the future direction of the process over Ni-based catalysts

Dichlorido{4-cyclohexyl-1-[1-(2- hyridyljN)ethylidene]thiosemicarbazidatoj2 N1 ,S}phenyltin(IV)

The SnIV atom in the title compound, [Sn(C6H5)(C14H19- N4S)Cl2], exists within a distorted octahedral geometry defined by the N,N0 ,S-tridentate monodeprotonated Schiff base ligand, two mutually trans Cl atoms, and the ipso-C atom of the Sn-bound phenyl group; the latter is trans to the azo-N atom. The greatest distortion from the ideal geometry is found in the nominally trans angle formed by the S and pyridyl-N atoms at Sn [151.03 (4)]. With the exception of the cyclohexyl group (chair form), the Schiff base ligand is almost planar (r.m.s. deviation of non-H and Sn atoms = 0.053 A˚ ). The nearly orthogonal orientation of the Sn-bound phenyl group [N—Sn—C—C torsion angle = 70.8 (5)] to the planar portion of the Schiff base allows for the formation of significant intramolecular C—HCl interactions which preclude the Cl atoms from participating in N—HCl hydrogen bonds. Instead, C—H contacts, involving methylene H and the Sn-bound phenyl group, lead to the formation of supramolecular chains that pack in the bc plane. Connections between these layers are of the type C—HCl

2-[(1,3-Benzothiazol-2-yl)iminomethyl]-6-methoxyphenol: A new monoclinic polymorph

The title compound, C15H12N2O2S, is a P21/c polymorph of a previously reported P21/n polymorph [Büyükgüngör et al. (2004). Acta Cryst. E60, o1414-o1416]. The dihedral angle between the benzothiazole (r.m.s. deviation = 0.010 Å) and the benzene ring of 7.86 (6)° compares with 10.76 (10)° in the literature structure. The methoxy substituent is almost coplanar with the benzene ring to which it is attached [C - O - C - C torsion angle = 178.31 (14)°] and the conformation about the imine bond [1.287 (2) Å] is E. There is an intramolecular O - H⋯N hydrogen bond and the hydroxy O and thioether S atoms are syn. In the crystal, columns are formed along the b axis as centrosymmetric dimeric aggregates, mediated by C - H⋯O interactions and linked by π-π interactions between the thiazole and benzene rings [centroid-to-centroid distance = 3.8256 (10) Å]