Biosynthesis of zinc oxide nanoparticles using Euphorbia milii leaf constituents: Characterization and improved photocatalytic degradation of methylene blue dye under natural sunlight

A facile biosynthesis route was followed to prepare zinc oxide nanoparticles (ZnO NPs) using Euphorbia milii (E. milii) leaf constituents. The SEM images exhibited presence of spherical ZnO NPs and the corresponding TEM images disclosed monodisperse nature of the ZnO NPs with diameter ranges between 12 and 20 nm. The Brunauer–Emmett–Teller (BET) analysis revealed that the ZnO NPs have specific surface area of 20.46 m²/g with pore diameter of 2 nm–10 nm and pore volume of 0.908 cm³/g. The EDAX spectrum exemplified the existence of Zn and O elements and non-appearance of impurities that confirmed pristine nature of the ZnO NPs. The XRD pattern indicated crystalline peaks corresponding to hexagonal wurtzite structured ZnO with an average crystallite size of 16.11 nm. The FTIR spectrum displayed strong absorption bands at 512 and 534 cm^?1 related to ZnO. The photocatalytic action of ZnO NPs exhibited noteworthy degradation of methylene blue dye under natural sunlight illumination. The maximum degradation efficiency achieved was 98.17% at an illumination period of 50 min. The reusability study proved considerable photostability of the ZnO NPs during photocatalytic experiments. These findings suggest that the E. milii leaf constituents can be utilized as suitable biological source to synthesis ZnO NPs for photocatalytic applications.     

A new entry to the isogeissoschizoid skeleton

[reaction: see text] The tetracyclic isogeissoschizoid skeleton has been prepared by a novel route that involves the ozonolysis and double reductive amination of a cyclopentene, a nickel-catalyzed cyclization, and a late-stage Fischer indole synthesis.     

Selective oxidation of sulfides to sulfoxides and sulfones at room temperature using H2O2 and a Mo(VI) salt as catalyst

Selective oxidation of sulfides to sulfoxides and sulfones is achieved by H₂O₂ using MoO₂Cl₂ as the catalyst. Various substituted sulfides having functional groups such as methyl, methoxy, bromo, nitro, alkene, alkyne, alcohol, ester, aldehyde and remarkably an oxime are successfully and selectively oxidized without affecting the sensitive functionalities.     

Synthesis of C60-diphenylaminofluorene dyad with large 2PA cross-sections and efficient intramolecular two-photon energy transfer

The first, highly two-photon active C60 derivative comprised of a A-sp3-D conjugate structure was synthesized showing effective two-photon absorption cross-sections (sigma 2' = 196 x 10(-48) cm4 sec-1 molecule-1) in the nanosecond regime among the best values for diphenylaminofluorene-based AFX chromophores.     

A molecular beam study of the NO + CO reaction on Pd(111) surfaces

Nitric oxide (NO) reduction with carbon monoxide (CO) on the Pd(111) surface was studied under isothermal conditions by molecular beam techniques as a function of temperature, NO:CO beam composition, and beam flux. Systematic experiments were performed under transient and steady state conditions. Displacement of adsorbed CO by NO in the transient state of the reaction was observed at temperatures between 375 and 475 K for all the NO:CO compositions studied. NO accumulation occurs on Pd(111) surface under steady state conditions, below 475 K, due to stronger chemisorption of NO. The steady state reaction rates attain a maximum at about 475 K, nearly independent of beam composition. N2 was found to be the major product of the reduction, along with a minor production of N2O. The production of N2 and N2O indicates molecular and dissociative adsorption of NO on Pd(111) at temperatures up to 525 K. Postreaction TPD measurements were performed in order to determine the nitrogen coverage under steady-state conditions. Finally, the results are discussed with respect to the rate-controlling character of the different elementary steps of the reaction system.     

3β‐(1‐Allyl‐1‐pyrrolidinio)‐16‐(2‐pyridylmethylene)androst‐5‐en‐17β‐ol bromide hemihydrate

The title compound, C₃₂H₄₅N₂O⁺·Br^?·0.5H₂O, has the outer two six‐membered rings in chair conformations, while the central ring is in an 8β,9α‐half‐chair conformation. The five‐mem­bered ring of the steroid nucleus adopts a slightly deformed 14α‐envelope conformation. The pyridyl­methyl­ene moiety has an E configuration with respect to the hydroxyl group at position 17. The structure is stabilized by a network of O—H?Br‐type intermolecular hydrogen bonds.     

Synthesis of novel S-neoglycopeptides from glycosylthiomethyl derivatives

Reaction of glycosylthiomethyl azides with amino acid and peptide derivatives containing aspartate and glutamate thio acids gave the corresponding glycosylthiomethyl amides in excellent yields. Another type of neoglycopeptides was obtained via reaction of glycosylthiomethyl bromide with cysteine and homocysteine containing peptide derivatives, thus affording the corresponding S-(glycosylthiomethyl) peptides.     

Stabilisation of [Fe2(CO)9] and [Ru2(CO)9] bu substitution with bridging diphosphorus ligands

Reaction of [Fe₂(CO)₉] with a half molar amount of R₂PYPR₂ (Y = CH₂, R = Ph, Me, OMe or OPrⁱ; Y = N(Et), R = OPh, OMe or OCH₂; Y = N(Me), R = OPrⁱ or OEt) leads to the ready formation of a product which on irradiation with ultraviolet light rapidly decarbonylates to the heptacarbonyl derivative [Fe₂(μ-CO)(CO)₆{μ-R₂PYPR₂}]. Treatment of the latter with a slight excess of the appropriate ligand results, under photochemical conditions, in the formation of the dinuclear pentacarbonyl complex [Fe₂(μ-CO)(C))₄{μ-R₂PYPR₂}₂] but under thermal conditions in the formation of the mononuclear species [Fe(CO)₃{R₂PYPR₂}]. Reaction of [Ru₃(CO)₁₂] with an equimolar amount of (RO)₂PN(R′)P(OR)₂ (R′ = Me, R = Prⁱ or Et; R′ = Et, R = Ph or Me) under either thermal or photochemical conditions produces [Ru₃(CO)₁₀{μ-(RO)₂PN(OR)₂}] which reacts further with excess (RO)₂PN(R′)P(OR)₂ on irradiation with ultraviolet light to afford the dinuclear compound [Ru₂(μ-CO)(CO₄{μ-(RO)₂PN(R′)P(OR)₂}₂]. The molecular structure of [Ru₂(μ-CO)(CO)₄{μ-(MeO)₂PN(Et)P(OMe)₂}₂], which has been determined by X-ray crystallography, is described.     

Crystal Structure Investigations of Inclusion Complexes Between β-cyclodextrin and Alkyl(aqua)cobaloximes (Alkyl=Butyl,Hexyl and Cyclohexyl)

The crystal and molecular structures of alkylcobaloxime/ g -cyclodextrin ( g -CD) inclusion complexes: butyl(aqua)cobaloxime/ g -CD ( 1 ). hexyl(aqua)cobaloxime/ g -CD ( 2 ) and cyclohexyl(aqua)cobaloxime/ g -CD ( 3 ) were determined by X-ray diffraction analyses. Crystal data for 1 14H 2 O: P 2 1 2 1 2 1 , a =15.1335(3), b =18.9630(2), c =28.1545(5) Å, Z =4; 2 12H 2 O: P 2 1 2 1 2 1 , a =15.1135(4), b =19.1477(5), c =28.2715(7) Å, Z =4; 3 10H 2 O: P 2 1 2 1 2 1 , a =15.6898(2), b =16.9094(2), c =28.9762(2) Å, Z =4. The structural and conformational comparisons for the three g -CD inclusion complexes with their guest molecules as well as other CD inclusion analogs are discussed.     

Photocatalytic Degradation of Organic Reactive Dyes over MnTiO3/TiO2 Heterojunction Composites Under UV‐Visible Irradiation

In this study, the photocatalytic degradation of organic reactive dyes have been investigated using MnTiO₃/TiO₂ heterojunction composites in the presence of electron acceptors under UV‐Visible light irradiation. This MnTiO₃/TiO₂ heterojunction composites were prepared by annealing different mass ratios of pyrophanite MnTiO₃ (3–11 wt%) and TiO₂ at 300°C. All the MnTiO₃/TiO₂ heterojunction composites were characterized by spectral techniques like X‐ray diffraction (XRD), scanning electron microscope (SEM) and diffused reflectance UV‐visible spectroscopic analysis (DRS). Among them, 9 wt% MnTiO₃/TiO₂ heterojunction composites exhibited higher photocatalytic activity for the degradation of Reactive Blue 4 (RB 4). The photocatalytic efficiency of 9 wt% MnTiO₃/TiO₂ heterojunction composites was further enhanced by the addition of substantial amount of electron acceptors like hydrogen peroxide (H₂O₂) and ammonium peroxydisulfate ([NH₄]₂S₂O₈). The presence of oxidants (electron acceptors) facilitates the fast degradation of dye solution even in higher concentration upto 200 mg/L. The photocatalytic activity of MnTiO₃/TiO₂ heterojunction composites was also studied for the degradation of other four different structured reactive dyes. The extent of mineralization of these organic reactive dyes during photocatalytic degradation was estimated from COD analysis. MnTiO₃/TiO₂ heterojunction composites was also found to have good photostability in the presence of oxidants.