Gold Nanoparticles Supported on Magnesium Oxide Nanorods for Oxidation of Alcohols.

Gold nanoparticles supported on magnesium oxide nanorods (Au-MgO) have been synthesised by a solution based chemical reduction method. Au-MgO nanorods were found to be an efficient heterogeneous catalyst for oxidation of alcohols with hydrogen peroxide in aqueous medium at room temperature. To find out the best reaction conditions for oxidation, optimization of catalyst quantity, solvent, mole equivalence of hydrogen peroxide were carried out. The scope of the reaction was extended to several aromatic and aliphatic alcohols, product yields were quantified by gas chromatography (GC) and GC/mass spectroscopy. Heterogeneity and reusability tests were performed. The use of water as a solvent and hydrogen peroxide as co-catalyst at room temperature makes the reaction interesting from sustainable development point of view.

Estimation of lattice strain in nanocrystalline RuO2 by Williamson-Hall and size-strain plot methods.

RuO2 nanoparticles (RuO2 NPs) have been successfully synthesized by the hydrothermal method. Structure and the particle size have been determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM). UV-Vis spectra reveal that the optical band gap of RuO2 nanoparticles is red shifted from 3.95 to 3.55eV. BET measurements show a high specific surface area (SSA) of 118-133m(2)/g and pore diameter (10-25nm) has been estimated by Barret-Joyner-Halenda (BJH) method. The crystallite size and lattice strain in the samples have been investigated by Williamson-Hall (W-H) analysis assuming uniform deformation, deformation stress and deformation energy density, and the size-strain plot method. All other relevant physical parameters including stress, strain and energy density have been calculated. The average crystallite size and the lattice strain evaluated from XRD measurements are in good agreement with the results of TEM.

Recyclable Mesoporous Ceria Supported Gold Nanoparticles Based Catalyst for O-Arylation of Phenols.

Ceria supported gold nanoparticles (Au-CeO2 NPs) were prepared by a simple deposition-precipitation method. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and Raman analysis indicated the formation of gold nanoparticles over phase pure cerianite ceria support. The presence of gold nanoparticles was well identified by UV-DRS study. In addition, the field emission scanning electron microscope (FESEM) and high resolution transmission electron microscope (HR-TEM) images revealed that the maximum number of particles having spherical shape were approximately 10 nm size. Subsequently, surface area of the catalyst determined from BET, Langmuir and DFT methods were found to be 83.1, 134 and 85.2 m2 g(-1) respectively. N2 absorption-desorption measurement revealed that Au-CeO2 NPs was mesoporous in nature. Au-CeO2 NPs proved to be an efficient catalyst for the O-arylation reactions. The reaction conditions were optimized using 2,6-dimethoxyphenol and 1-chloro-4-nitrobenzene as a model substrate by changing the solvent, base, quantity of catalyst, and temperature. The scope of the work was extended to various substituted phenols and aryl halides (F, Cl and Br) and reusability of catalyst was tested for four cycles which showed no loss in its activity.

Crystal structure of N-[(4-eth-oxy-phen-yl)carbamo-thio-yl]cyclo-hexa-ne-carboxamide.

The asymmetric unit of the title compound, C16H22N2O2S, contains two crystallographically independent mol-ecules (A and B). In mol-ecule A, the cyclo-hexane ring is disordered over two orientations [occupancy ratio 0.841 (10):0.159 (10)]. In each mol-ecule, the central carbonyl thio-urea unit is nearly planar (r.m.s. deviations for all non-H atoms of 0.034 Šin mol-ecule A and 0.094 Šin mol-ecule B). In both mol-ecules, the cyclo-hexane ring adopts a chair conformation. The mean plane of the cyclo-hexane ring makes dihedral angles of 35.8 (4) (mol-ecule A) and 20.7 (3)° (mol-ecule B) with that of the benzene ring. Each mol-ecule features an intra-molecular N-H⋯O hydrogen bond, which closes an S(6) ring motif. In the crystal, mol-ecules are linked via pairs of weak N-H⋯S inter-actions, forming inversion dimers with an R 2 (2)(8) ring motif for both mol-ecules. The crystal structure also features weak C-H⋯π ring inter-actions.

Crystal structure of N-[(naphthalen-1-yl)carbamo-thio-yl]cyclo-hexa-necarboxamide.

The title compound, C18H20N2OS, displays whole-mol-ecule disorder over two adjacent sets of sites with an occupancy ratio of 0.630 (11):0.370 (11). In each disorder component, the cyclo-hexyl ring shows a chair conformation with the exocyclic C-C bond in an equatorial orientation. The dihedral angles between the cyclo-hexyl ring (all atoms) and the naphthyl ring system are 36.9 (6) for the major component and 20.7 (12)° for the minor component. Each component features an intra-molecular N-H⋯O hydrogen bond, which closes an S(5) ring. In the crystal, inversion dimers linked by pairs of N-H⋯S hydrogen bonds generate R (2) 2(8) loops for both components. Aromatic π-π stacking inter-actions [shortest centroid-centroid separation = 3.593 (9) Å] and a C-H⋯π inter-action are also observed.

Crystal structure of (Z)-2-(1-benzyl-2-oxoindolin-3-yl-idene)-N-phenyl-hydra-zine-1-carbo-thio-amide.

The title compound, C22H18N4OS, crystallized with four independent mol-ecules (A, B, C and D) in the asymmetric unit. All four mol-ecules have a Z conformation about the C=N bond with the benzyl ring being inclined to the indoline ring mean planes by 73.4 (2), 77.9 (2), 73.2 (2) and 77.2 (2)° in mol-ecules A, B, C and D, respectively. In mol-ecules A and B, the phenyl ring is inclined to the mean plane of the indoline ring mean plane by 12.0 (2) and 12.2 (2)°, respectively. However, in mol-ecules C and D, the same dihedral angles are larger, viz. 37.3 (2) and 36.4 (2)°, respectively. Consequently, the benzyl and phenyl rings are almost normal to one another in mol-ecules A and B [dihedral angles = 80.3 (3) and 87.1 (3)°, respectively], while in mol-ecules C and D, the same dihedral angles are only 48.8 (2) and 43.8 (3)°, respectively. There is an intra-molecular N-H⋯O hydrogen bond in each mol-ecule with an S(6) ring motif. There are also short intra-molecular N-H⋯N and C-H⋯S contacts in each mol-ecule. In the crystal, mol-ecules are linked via C-H⋯S hydrogen bonds and C-H⋯π inter-actions, forming a three-dimensional structure. The crystal was refined as a non-merohedral twin with a final BASF value of 0.110 (1).

Crystal structure of (2E)-N-methyl-2-(2-oxo-1,2-di-hydroacenaphthylen-1-ylidene)hydrazinecarbo-thioamide.

In the title compound, C14H11N3OS, the ace-naphthyl-ene ring system and hydrazinecarbo-thio-amide unit (=N-NH-C=S-NH-) are essentially coplanar [with maximum deviations from their mean planes of -0.009 (2) and 0.033 (2) Å, respectively], and make a dihedral angle of 1.59 (9)°. The mol-ecular conformation is stabilized by two weak intra-molecular hydrogen bonds (N-H⋯O and N-H⋯N), which generate S(6) and S(5) ring motifs. In the crystal, mol-ecules are linked by N-H⋯S hydrogen bonds, forming chains along [010]. The chains are linked via pairs of C-H⋯O hydrogen bonds, enclosing R (2) 2(10) ring motifs, and C-H⋯π inter-actions, forming a three-dimensional framework. The absolute structure of the title compound was determined by resonant scattering.

Crystal structure of (2E)-N-methyl-2-[(4-oxo-4H-chromen-3-yl)methyl-idene]hydrazine-carbo-thio-amide.

In the title compound, C12H11N3O2S, the dihedral angle between the 4H-chromen-4-one ring system and the -CH=N-NH-CS-NH- unit is 6.22 (1)°. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds generate R 2 (2)(14) loops. The dimers are reinforced by a pair of C-H⋯O inter-actions, which generate R 2 (2)(10) loops.

3-({[Bis(2-methyl-prop-yl)carbamo-thio-yl]amino}-carbon-yl)benzamide.

In the title compound, C17H25N3O2S, the terminal and central amide groups are, respectively, twisted and coplanar with the attached benzene ring [O-C-C-C torsion angles = 22.7 (3) and 5.4 (3)°]. In the central part of the mol-ecule, the amide and thio-amide residues are approximately perpendicular [C-N-C-S torsion angle = -104.98 (18)°]. Supra-molecular layers with a zigzag topology are formed in the crystal packing by N-H⋯O, N-H⋯S and C-H⋯O inter-actions; these stack along c, being separated by hydro-phobic inter-actions.

3-{[(Di-benzyl-carbamo-thio-yl)amino]-carbon-yl}benzamide.

Two independent mol-ecules with quite similar conformations, A and B, comprise the asymmetric unit of the title compound, C23H21N3O2S. The terminal amide substituent is coplanar with the attached benzene ring [the O-C-C-C torsion angles are 174.0 (2) (A) and 6.3 (3)° (B)]. In the same way, the central amide group [C-C-C-O = 7.8 (3) (A) and 11.5 (3)° (B)] is approximately coplanar with the ring to which it is attached. A major twist is noted between the amide and adjacent thio-amide residues [C-N-C-S = -109.29 (19) (A) and -112.29 (19)° (B)]. In the crystal, supra-molecular chains along [100] are formed by N-H⋯O and N-H⋯S hydrogen bonding. These are connected into a three-dimensional architecture by C-H⋯π and π-π inter-actions [inter-centroid distance = 3.9157 (12) Å].

Mesoporous nickel-aluminosilicate nanocomposite: a solid acid catalyst for ether synthesis.

Mesoporous nickel aluminosilicate, a solid acid catalyst prepared by sol-gel technique was utilized as a heterogeneous catalyst for the synthesis of symmetrical ethers by dehydro-condensation of alcohols. The prepared catalysts were characterized by Fourier-transform infra red spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), N2 adsorption-desorption analysis, temperature programmed desorption of ammonia (TPD) and X-ray photoelectron spectroscopic techniques. The presence of the catalyst assisted the etherification reaction in 30 minutes. Ethers formed in these reactions were quantified by gas chromatography (GC) and the identities of few of them were confirmed by nuclear magnetic resonance spectral data (NMR).

1-[3-({[Bis(2-methyl-prop-yl)carbamo-thio-yl]amino}-carbon-yl)benzoyl]-3,3-bis-(2-methyl-prop-yl)thio-urea.

The title compound, C26H42N4O2S2, adopts a shallow U-shape as both pendant arms of the 1,3-substituted benzene ring are orientated in the same direction. The thione S atoms lie to the same side of the benzene ring and the carbonyl O atoms to the other. The most prominent feature of the crystal packing is the formation of inversion dimers mediated by N-H⋯S hydrogen bonds. One of the 2-methyl-propyl groups is statistically disordered over two positions.

Abatement of mixture of volatile organic compounds (VOCs) in a catalytic non-thermal plasma reactor.

Total oxidation of mixture of dilute volatile organic compounds was carried out in a dielectric barrier discharge reactor with various transition metal oxide catalysts integrated in-plasma. The experimental results indicated the best removal efficiencies in the presence of metal oxide catalysts, especially MnO(x), whose activity was further improved with AgO(x) deposition. It was confirmed water vapor improves the efficiency of the plasma reactor, probably due to the formation of hydroxyl species, whereas, in situ decomposition of ozone on the catalyst surface may lead to nascent oxygen. It may be concluded that non-thermal plasma approach is beneficial for the removal of mixture of volatile organic compounds than individual VOCs, probably due to the formation of reactive intermediates like aldehydes, peroxides, etc.

Dibenzyl-aza-nium chloride.

In the title salt, C(14)H(16)N(+)·Cl(-), the complete cation and complete anion are generated by the application of mirror symmetry. The mol-ecule is nonplanar, as seen in the dihedral angle between the terminal phenyl rings [70.92 (5)°]. In the crystal, N-H⋯Cl hydrogen bonds involving both aza-nium H atoms link the ions into a zigzag supra-molecular chain along [100].

1-Benzoyl-3-(4-chloro-phen-yl)thio-urea dichloro-methane hemisolvate.

In the title hemisolvate, C14H11ClN2OS·0.5CH2Cl2, an anti disposition is found for the thione and ketone atoms, as well as the N-H H atoms; the dichloro-methane C atom lies on a twofold axis. The central chromophore (including the two adjacent ipso C atoms) is planar (r.m.s. deviation = 0.021 Å) owing to the presence of an intra-molecular N-H⋯O hydrogen bond, which closes an S(6) loop. Significant twists are evident in the mol-ecule, the dihedral angles between the central moiety and the phenyl and benzene rings being 29.52 (7) and 40.02 (7)°, respectively. In the crystal, eight-membered {⋯HNC= S}2 synthons with twofold symmetry form via N-H⋯S hydrogen bonds. The dimers are connected into a supra-molecular chain along [111] by C-H⋯O inter-actions. The chains stack along the c axis, forming columns which define channels in which the occluded dichloro-methane mol-ecules reside.

3-Benzoyl-1-(2-meth-oxy-phen-yl)thio-urea.

In the title compound, C15H14N2O2S, the central C2N2OS moiety is planar (r.m.s. deviation of fitted atoms = 0.0336 Å). This is ascribed to the formation of an S(6) loop stabilized by an intra-molecular N-H⋯O hydrogen bond; additional intramolecular N-H⋯O and C-H⋯S contacts are also noted. The dihedral angles between the central unit and the phenyl and benzene rings are 23.79 (7) and 29.52 (5)°, respectively. The thione S and ketone O atoms are mutually anti, as are the N-H H atoms; the O atoms lie to the same side of the mol-ecule. Centrosymmetric eight-membered {⋯HNC=S}2 synthons feature in the crystal packing. The resulting inversion dimers stack along the a axis and are connected into a three-dimensional structure by C-H⋯O and C-H⋯π inter-actions.

Bis(3-benzoyl-1,1-di-sec-butyl-thio-ureato-κO,S)palladium(II).

The complex mol-ecule of the title complex, [Pd(C(16)H(23)N(2)OS)(2)], is completed by crystallographic twofold symmetry with the metal atom lying on the rotation axis. The Pd(II) atom exists within a slightly distorted square-planar geometry defined by a cis-O(2)S(2) donor set. The dihedral angle formed between the mean planes of the symmetry-related six-membered chelate rings is 12.88 (7)° and the bond lengths within the rings are indicative of significant electron delocalization. In the crystal, mol-ecules aggregate into dimers linked by four C-H⋯O inter-actions.

{4-Bromo-2-[(2-sulfido-phen-yl)imino-meth-yl]phenolato-κS,N,O}(triphenyl-phosphane-κP)nickel(II).

The Ni(II) atom in the title complex, [Ni(C(13)H(8)BrNOS)(C(18)H(15)P)], is coordinated by the N, O and S atoms of the dianionic tridentate ligand, and its square-planar geometry is completed by a phosphane P atom. The dihedral angle between the aromatic rings in the 4-bromo-2-[(2-sulfido-phen-yl)imino-meth-yl]phenolate ligand is 2.01 (14)°. The most prominent feature of the packing is the presence of supra-molecular chains aligned along the a axis, mediated by C-H⋯S inter-actions.

1-Benzoyl-3-methyl-3-pentyl-thio-urea.

Two independent mol-ecules comprise the asymmetric unit of the title compound, C(14)H(20)N(2)OS. These differ in the relative orientations of the pentyl chains [C-C-C-C torsion angles = -176.7 (3) and 176.4 (3)°]. Significant twists are evident in each mol-ecule, the dihedral angles formed between the thio-urea and amide residues being 53.47 (17) and 55.81 (17)°. In the crystal, each mol-ecule self-associates via a centrosymmetric eight-membered {⋯HNC=S}(2) synthon, and these are connected into a supra-molecular chain along [110] via C-H⋯O contacts. Disorder is noted for one of the independent mol-ecules in that two orientations (50:50) were resolved for its benzene ring.

1-Benzoyl-3,3-bis-(2-methyl-prop-yl)thio-urea.

The title compound, C(16)H(24)N(2)OS, is twisted about the central N(H)-C bond with the C-N-C-S torsion angle being 119.6 (3)°. The carbonyl O and thione S atoms are directed to opposite sides of the mol-ecule, a conformation that allows for the formation of a linear supra-molecular chain comprising alternating eight-membered {⋯HNCS}(2) and 14-membered {⋯HCNCNCO}(2) synthons.