Iron and 4-(methylamino)benzoic acid have been successfully incorporated into silica extracted from rice husk. The silica/Fe/amine complex, RH-Fe(5% amine), showed a ca. 24% increase in specific surface area compared to RH-Fe. This increase was attributed to the templated formation of regular pores. The XRD showed the RH-Fe(5% amine) to be amorphous. The Friedel-Crafts benzylation reaction with toluene using RH-Fe(5% amine) showed a drastic reduction in the di-substituted products to ca. 1.0%.
Silica-incorporated aluminum (RHA-Al) was synthesized from rice husk ash (RHA) using the sol-gel technique. RHA-Al was calcined at 500 degrees C for 5 h to yield RHA-Al(C). The ratio of silica to alumina was found to be 4:1. The BET analysis of RHA-Al(C) showed an increase in total pore volume and specific surface area compared to RHA-Al. SEM and XRD showed that RHA-Al and RHA-Al(C) were composed of microcrystals and the surface of both samples had a porous structure. Adsorption studies of palmytic acid on RHA-Al and RHA-Al(C) at 30, 40, and 50 degrees C conformed to the Langmuir isotherm. The equilibrium parameter, R, revealed that both are good adsorbents for palmytic acid. The Gibbs free energy of adsorption, DeltaG(ads)(0), was determined to be between -21.0 and -26.0 kJ mol(-1). DeltaH(ads)(0) and DeltaS(ads)(0) for RHA-Al were found to be 26.2 kJ mol(-1) and 158 J mol(-1), respectively. Corresponding values for RHA-Al(C) were 31.7 kJ mol(-1) and 178 J mol(-1). The adsorption of fatty acid on RHA-Al and RHA-Al(C) was an endothermic process, which occurred spontaneously. An FTIR study on the adsorbed material was used to determine the possible adsorbed complex on the surface of the adsorbent.
In the title compound, C16H17N3OS, a benzoyl thio-urea derivative, the planes of the pyridine and benzene rings are inclined to one another by 66.54 (9)°. There is an intra-molecular N-H⋯O hydrogen bond present forming an S(6) ring motif. In the crystal, mol-ecules are linked via pairs of N-H⋯N hydrogen bonds, forming inversion dimers, which are reinforced by pairs of C-H⋯S hydrogen bonds. The dimers are linked via C-H⋯π inter-actions, forming ribbons along [010].
In the title compound, C16H17N3OS, the dihedral angle between the planes of the benzene and pyridine rings is 71.33 (15)°. An intra-molecular N-H⋯O hydrogen bond is present. In the crystal, weak aromatic C-H⋯O hydrogen bonds link the mol-ecules into chains extending along a.
Titania and ceria incorporated rice husk silica based catalyst was synthesized via sol-gel method using CTAB and glycerol as surface directing agents at room temperature and labeled as RHS-50Ti10Ce. The catalyst was used to study the adsorption and photodegradation of methylene blue (MB) under UV irradiation. The powder XRD pattern of RHS-50Ti10Ce was much broader (2θ=25-30°) than that of the parent RHS (2θ=22°). The catalyst exhibited type IV isotherm with H3 hysteresis loop, and the TEM images showed partially ordered pore arrangements. The TGA-DTG thermograms confirmed the complete removal of the templates after calcination at 500°C. RHS-50Ti10Ce exhibited excellent adsorption capability with more than 99% removal of MB from a 40 mg L(-1) solution in just 15 min. It also decolorized an 80 mg L(-1) MB solution under UV irradiation in 210 min, which was comparable with the commercialized pure anatase TiO2.
Sodium silicate from rice husk ash (RHA) was transformed to functionalized silica with 3-(chloropropyl)triethoxysilane (CPTES) via a simple sol-gel technique in a one-pot synthesis. The (29)Si MAS NMR of the organo-silica complex (RHACCl) showed the presence of T(2), T(3), Q(3) and Q(4) silicon centers. The (13)C MAS NMR showed that RHACCl had three chemical shifts at 10.37, 26.70 and 47.69 ppm consistent with the three carbon atoms of the CPTES moiety. The presence of carbon, silicon and chlorine was determined by a combination of elemental analysis and EDX study.
Silica supported iron catalyst was prepared from rice husk ash (RHA) via the sol-gel technique using an aqueous solution of iron(III) salt in 3.0 M HNO3. The sample was dried at 110 degrees C and labeled as RHA-Fe. A sample of RHA-Fe was calcined at 700 degrees C for 5 h and labeled as RHA-Fe700. X-ray diffraction spectrogram showed that both RHA-Fe and RHA-Fe700 were amorphous. The SEM/EDX results showed that the metal was present as agglomerates and the Fe ions were not homogeneously distributed in RHA-Fe but RHA-Fe700 was shown to be homogeneous. The specific surface areas for RHA-Fe and RHA-Fe700 were determined by BET nitrogen adsorption studies and found to be 87.4 and 55.8 m(2) g(-1), respectively. Both catalysts showed high activity in the reaction between toluene and benzyl chloride. The mono-substituted benzyltoluene was the major product and both catalysts yielded more than 92% of the product. The GC showed that both the ortho- and para-substituted monoisomers were present in about equal quantities. The minor products consisting of 16 di-substituted isomers were also observed in the GC-MS spectra of both catalytic products. The catalyst was found to be reusable without loss of activity and with no leaching of the metal.
Cu doped InVO4 (xCu-InVO4 (x = 0.06-0.15 wt %) was synthesized by a facile one-pot hydrothermal method for the removal of methylene blue (MB) under LED light irradiation. The X-ray photoelectron spectroscopy (XPS) analysis indicated the coexistence of V5+ and V4+ species due to the O-deficient nature of the xCu-InVO4. The synthesized photocatalysts displayed a morphology of spherical and square shaped particles (20-40 nm) and micro-sized rectangle rods with a length range of 100-200 μm. The xCu-InVO4 exhibited superior adsorption and photodegradation efficiency compared to pristine InVO4 and TiO2 due to the presence of O2 vacancies, V4+/V5+ species, and Cu dopant. The optimum reaction conditions were found to be 5 mg L-1 (MB concentration), pH 6, and 100 mg of photocatalyst mass with a removal efficiency and mineralization degree of 100% and 96.67%, respectively. The main active species responsible for the degradation of MB were •OH radicals and h+. Reusability studies indicated that the 0.13Cu-InVO4 was deactivated after a single cycle of photocatalytic reaction due to significant leaching of V4+ and Cu2+ species.
In the title compound, C10H13N3OS, the azomethine C=N double bond has an E configuration. The phenyl ring and methyl-hydrazine carbo-thio-amide moiety [maximum deviation = 0.008 (2) Å] are twisted slightly with a dihedral angle of 14.88 (10)°. In the crystal, mol-ecules are linked into sheets parallel to the ab plane via N-H⋯S hydrogen bonds and C-H⋯π inter-actions.
The asymmetric unit of the title compound, C15H21N3OS, comprises of two crystallographically independent mol-ecules (A and B). Each mol-ecule consists of a cyclo-hexane ring and a 2-hy-droxy-3-methyl-benzyl-idene ring bridged by a hydrazinecarbo-thio-amine unit. Both mol-ecules exhibit an E configuration with respect to the azomethine C=N bond. There is an intra-molecular O-H⋯N hydrogen bond in each mol-ecule forming an S(6) ring motif. The cyclo-hexane ring in each mol-ecule has a chair conformation. The benzene ring is inclined to the mean plane of the cyclo-hexane ring by 47.75 (9)° in mol-ecule A and 66.99 (9)° in mol-ecule B. The mean plane of the cyclo-hexane ring is inclined to the mean plane of the thio-urea moiety [N-C(=S)-N] by 55.69 (9) and 58.50 (8)° in mol-ecules A and B, respectively. In the crystal, the A and B mol-ecules are linked by N-H⋯S hydrogen bonds, forming 'dimers'. The A mol-ecules are further linked by a C-H⋯π inter-action, hence linking the A-B units to form ribbons propagating along the b-axis direction. The conformation of a number of related cyclo-hexa-nehydrazinecarbo-thio-amides are compared to that of the title compound.
The PtII atom in the title complex, [Pt(C15H18N4O4S)(C2H6OS)], exists within a square-planar NS2O donor set provided by the N, S, O atoms of the di-anionic tridentate thio-semicarbazo ligand and a dimethyl sulfoxide S atom. The two chelate rings are coplanar, subtending a dihedral angle of 1.51 (7)°. The maximum deviation from an ideal square-planar geometry is seen in the five-membered chelate ring with an S-Pt-S bite angle of 96.45 (2)°. In the crystal, mol-ecules are linked via N-H⋯O, C-H⋯O, C-H⋯N and C-H⋯π inter-actions into two-dimensional networks lying parallel to the ab plane. The conformations of related cyclo-hexyl-hydrazine-1-carbo-thio-amide ligands are compared to that of the title compound.
There are two mol-ecules in the asymmetric unit of the title compound, C9H10N2OS. In one, the dihedral angle between the aromatic ring and the carbamo-thioyl group is 52.31 (7)° and in the other it is 36.16 (6)°. Each mol-ecule features an intra-molecular N-H⋯O hydrogen bond, which generates an S(6) ring and the O and S atoms have an anti disposition. In the crystal, mol-ecules are linked by N-H⋯S and N-H⋯O hydrogen bonds, generating separate [130] and [1-30] infinite chains. Weak C-H⋯O and C-H⋯S inter-actions are also observed.
In the title compound, C15H15N3OS, the dihedral angle between the planes of the benzene and pyridine rings is 26.86 (9)°. Intra-molecular N-H⋯O and C-H⋯S hydrogen bonds both generate S(6) rings. The C=O and C=S bonds lie to opposite sides of the mol-ecule. In the crystal, inversion dimers linked by pairs of N-H⋯S hydrogen bonds generate R 2 (2)(8) loops.
Solid acid catalyzed cracking of waste oil-derived fatty acids is an attractive route to hydrocarbon fuels. HZSM-5 is an effective acid catalyst for fatty acid cracking; however, its microporous nature is susceptible to rapid deactivation by coking. We report the synthesis and application of hierarchical HZSM-5 (h-HZSM-5) in which silanization of pre-crystallized zeolite seeds is employed to introduce mesoporosity during the aggregation of growing crystallites. The resulting h-HZSM-5 comprises a disordered array of fused 10-20 nm crystallites and mesopores with a mean diameter of 13 nm, which maintain the high surface area and acidity of a conventional HZSM-5. Mesopores increase the yield of diesel range hydrocarbons obtained from oleic acid deoxygenation from ~20% to 65%, attributed to improved acid site accessibility within the hierarchical network.
The title compound, C19H21N3O, comprises a central pyrazole ring which is N-connected to an aldehyde group and C-connected twice to substituted benzene rings. The pyrazole ring is twisted on the C-C single bond, and the least-squares plane through this ring forms dihedral angles of 82.44 (5) and 4.52 (5)° with the (di-methyl-amino)-benzene and p-tolyl rings, respectively. In the crystal, weak C-H⋯O hydrogen bonds link mol-ecules into supra-molecular tubes along the b axis.
In the title compound, C24H20N2, the dihedral angles between the pyrazole ring and the pendant phenyl, toluoyl and phenyl-ethenyl rings are 41.50 (8), 4.41 (8) and 31.07 (8)°, respectively. In the crystal, inversion dimers linked by a π-π stacking inter-actions between the phenyl-ethenyl rings are observed [centroid-centroid separation = 3.5857 (9) Å].
The title compound, C20H20N2O, was studied as a part of our work on pyrazoline derivatives. It represents a trans-isomer. The central pyrazoline ring adopts an envelope conformation with the asymmetric C atom having the largest deviation of 0.107 (1) Å from the mean plane. It forms dihedral angles of 6.2 (1) and 86.4 (1)° with the adjacent p-tolyl and styrene groups, respectively. In the crystal, C-H⋯O inter-actions link mol-ecules into infinite chains along the c axis.
In the title compound, C18H18N2O2, the pyrazole ring has a twisted conformation on the CH-CH2 bond. The tolyl ring and the 4-meth-oxy-phenyl ring are inclined to the mean plane of the pyrazole ring by 4.40 (9) and 86.22 (9)°, respectively, while the two aromatic rings are inclined to one another by 88.75 (9)°. In the crystal, mol-ecules are linked via bifurcated C-H⋯(O,O) hydrogen bonds and C-H⋯π inter-actions, forming sheets lying parallel to the ab plane.
The mol-ecule of the title Schiff base compound, C14H14N2O2, displays an E conformation with respect the imine C=N double bond. The mol-ecule is approximately planar, with the dihedral angle formed by the planes of the pyridine and benzene rings being 5.72 (6)°. There is an intra-molecular hydrogen bond involving the phenolic H and imine N atoms.
In the mol-ecule of the title compound, C21H17N3O2, the 5,6-di-hydro-benzimidazo[1,2-c]quinazoline moiety is disordered over two orientations about a pseudo-mirror plane, with a refined occupancy ratio of 0.863 (2):0.137 (2). The dihedral angles formed by the benzimidazole ring system and the benzene ring of the quinazoline group are 14.28 (5) and 4.7 (3)° for the major and minor disorder components, respectively. An intra-molecular O-H⋯O hydrogen bond is present. In the crystal, mol-ecules are linked by O-H⋯N hydrogen bonds, forming chains running parallel to [10-1].