a simple and green chemical procedure was reported for the synthesis of dihydropyrimidinones from various aldehydes, ethyl acetoacetate and urea or thiourea using  holmium chloride as catalyst. the reactions were performed under solvent free conditions with ultrasound irradiation as the energy source. the advantages of this protocol include the excellent yield, operational simplicity, short tim...

The Camphor sulphonic acid doped polyaniline (CSA-PANi)is synthesized by chemical polymerization method and then characterized by using UV-Visible and FTIR. The surface morphology is studied by SEM and AFM techniques. The degree of crystallinity of PANiis studied by XRD and redox behaviour by cyclic voltametry. Thermal stability of the doped polymer is investigated by TGA and DSC.The fluorescen...

Biocatalysis is generally regarded as a "green" technology. This statement is justified by the mild reaction conditions, the use of aqueous reaction media-with water as the paradigm of green solvents-, and the renewable nature of the biocatalysts. However, researchers making these statements frequently do not take into account the entire picture of their processes. Aspects like water consumptio...

The study of a UV-VIS spectrum of 8-hydroxyquinoline (8HQ) in different solvents can provide relevant information concerning the influence of the medium on the electronic structure of the solute or the nature and strength of the specific solvent-solute intraor intermolecular interactions. The electronic absorption spectra of 8-hydroxyquinoline in various solvents have very different features du...

Chemical biology relies on effective synthetic chemistry for building molecules to probe and modulate biological function. Olefin metathesis in organic solvents is a valuable addition to this armamentarium, and developments during the previous decade are enabling metathesis in aqueous solvents for the manipulation of biomolecules. Functional group-tolerant ruthenium metathesis catalysts modifie...

The chemical regeneration of granular activated carbon exhausted in a petrochemical wastewater unit was investigated. Gas chromatography and energy-dispersive X-ray spectroscopy demonstrated that spent activated carbon carries large types of organic and inorganic materials. Diverse chemical solvents were adopted in comparison with traditional chemical solvents and regeneration efficiency was in...

Membrane contactors offer promising performances for the intensification of gas liquid absorption processes. Impressive volume reduction factors compared to packed columns have been reported, mostly in chemical solvents (e.g. CO2 post combustion capture with MEA). A very limited number studies addressed however potentialities membrane physical Moreover, interplay between and energy requirement,...

Efficient synthetic methods that avoid the extensive use of hazardous reagents and solvents, as well harsh reaction conditions, have become paramount in field organic synthesis. Organocatalysis is notably one best tools building chemical bonds between carbons carbon-heteroatoms; however, most examples still employ toxic volatile solvents. Although a portfolio greener solvents now commercially a...

The importance of aprotic solvents in studies of the electrochemistry of organic compounds is discussed and a general mechanism for the oxidation and reduction of aromatic hydrocarbons and related substances is presented. The effect of molecular structure on the electrochemical behaviour of organic compounds is illustrated by discussing the relationship between conformations of aryl-substituted...

Treatment of hydrogen sulfide (H2S) is important in many industrial processes including oil refineries, natural and biogas processing, coal gasification. The most mature technology for the selective capture H2S based on its absorption by chemical or physical solvents. However, only several compounds are currently used as (co)solvents industry, search new ones an task. experimental screening req...