rac-3-[(Anilino)(naphthalen-2-yl)­methyl]thian-4-one

In the title compound, C22H21NOS, the thio­pyran­one ring adopts a chair-like conformation with the substituent in the axial position. The relative configuration of the racemic compound is 3R,7S according to the numbering scheme used in this publication. In the crystal packing, centrosymmetric dimers are built up via N—H⋯O hydrogen bonds, with graph set R 2 2(8)

rac-3-[(3-Chloro­anilino)(4-chloro­phenyl)meth­yl]thian-4-one

In the title compound, C18H17Cl2NOS, the thio­pyran­one ring adopts a chair conformation, with the substituent in the axial position. The dihedral angle between the two benzene rings is 89.43 (1)°. In the crystal, mol­ecules form inversion dimers through inter­molecular N—H⋯O hydrogen bonds [graph set R 2 2(8)]

(2E,6E)-2,6-Bis(4-methyl­benzyl­idene)cyclo­hex-3-en-1-one

The title compound, C22H20O, shows an approximately planar cyclo­hexenone ring [maximum deviation = 0.069 (4) Å], with a disordered position of the C=C bond [ratio = 0.71 (2)/0.29 (2)]. The benzene rings of the 4-methyl­benzyl­idene units, attached in the 2- and 6-positions to the cyclo­hexenone ring, are rotated in the same direction by 28.6 (4) and 22.4 (4)°, with respect to the mean plane of the cyclo­hexenone ring [fraction 0.71 (2); maximum deviation = 0.06 (3) Å]. In the crystal, mol­ecules are packed in the manner of a distorted hexa­gonal rod packing with their long axes all aligned along [201]. A number of C—H⋯π inter­actions stablize the crystal structure

(4Z,6Z)-4,6-Bis(4-meth­oxy­benzyl­idene)-2,2-dimethyl-1,3-dioxan-5-one

The title compound, C22H22O5, crystallizes with two independent mol­ecules in the asymmetric unit, both of which possess pseudo-C s symmetry. The central 1,3-dioxanone rings have envelope conformations, with the C atom bearing the two methyl groups at the flap. The benzene rings of the meth­oxy­benzyl­idene units, attached in the 4- and 6-positions on the central 1,3-dioxanone rings, are tilted in the same direction with dihedral angles varying between 8.2 (1) and 18.1 (1)°. The crystal packing is influenced by π-stacking inter­actions of the parallel displaced type [centroid–centroid distance of 3.723 (1) Å for mol­ecule 1 and 3.884 (1) Å for mol­ecule 2, with ring slippages of 1.432 and 1.613 Å, respectively] and the T-shaped type, with the long mol­ecular axes all aligned along [010]

NiO–MgO Solid Solution Prepared by Sol–Gel Method as Precursor for Ni/MgO Methane Dry Reforming Catalyst: Effect of Calcination Temperature on Catalytic Performance

International audienceThe influence of calcination temperature (500, 600 and 700 °C) on NiO–MgO solid solution formation and the performance of the resulting catalysts in CO2 reforming of methane was studied. The solid solutions and resulting catalysts were characterized by Brunauer–Emmett–Teller, XRD, temperature-programmed reduction (TPR), TEM and thermal gravimetric analysis techniques. Catalytic performance tests were carried out under 550–750 °C, 1 bar, CO2/CH4 = 1–3 mol/mol and space velocities of 30,000–120,000 ml/(h gcat). The catalyst calcined at 600 °C exhibited the best performance in terms of catalytic activity and stability and showed lowest amount of coke formation after 50 h-on-stream. The effect of calcination temperature on degree of NiO–MgO solid solution formation was demonstrated by both XRD and TPR profiles. The 600 °C calcination temperature was found to be an optimum as it caused modest NiO–MgO interaction, which is responsible for complete formation of the NiO–MgO solid solution with high nickel dispersion and resistant to coke formation