Green Chemistry Route Research Articles

Selective growth of gold nanoparticles onto tellurium nanowires via a green chemical route

In this paper, we describe a green chemical route for highly selective growth of Au tips onto Te nanowires (NWs). We carefully selected the pH values to vary the redox reaction potential between Au3+ and Te NWs, allowing control of nucleation and growth rates of Au nanoparticles (NPs). In the presence of 10 mM CTAB, we obtained Au-Te and Au-Te-Au NWs at pH 4.0 and 5.0, respectively. Photovoltaic data revealed that the resistance of the Te NW-based thin films is controlled by the degree of deposition of Au NPs. We suspect that Au-Te and/or Au-Te-Au NWs hold great potential for use in the fabrication of electronic devices.

Microwave-assisted synthesis, characterization and biological screening of nitrogen–sulphur and nitrogen–oxygen donor ligands and their organotin(IV) complexes

Series of new trigonal bipyramidal and octahedral complexes of tin(IV) have been synthesized by the reaction of dimethyltin(IV) dichloride with 4-nitro-benzanilidethiosemicarbazone (L 1H), 4-chlorobenzanilidethiosemicarbazone (L 2H), 4-nitrobenzanilidesemicarbazone (L 3H) and 4-chlorobenzanilidesemicarbazone (L 4H). The unimolecular and bimolecular reactions of dimethyltin(IV) dichloride and monobasic bidentate ligands were carried out using microwave irradiations as the thermal energy source and the complexes so formed were characterized by elemental analysis, conductance measurements, molecular weight determinations and spectral data, viz. IR, UV–vis, 1H and 13C NMR. The complexes have also been prepared by the general thermal methods for comparison purposes. The comparison data support the synthesis using the microwave route, i.e. green chemistry route. The tin(IV) complexes show penta-coordinated structure for 1:1 complexes and hexa-coordinated for 1:2 complexes. The antifungal, antibacterial and antifertility activities have been examined and the results were indeed very encouraging.

Large-Scale Synthesis, Growth Mechanism, and Photoluminescence of Ultrathin Te Nanowires

In this paper, a green chemical synthetic route was developed to synthesize single-crystalline Te nanowires with an average diameter of 7 nm at a low temperature (90 °C) by using ascorbic acid as a reducing agent, Na2TeO3 as a tellurium source, and surfactant cetyltrimethylammonium bromide (CTAB) as a structure-directing agent. The morphology of Te nanowires in the presence of CTAB is strongly dependent on the reaction conditions such as the concentration of CTAB, reaction time, and reducing agents. A surfactant-assisted solid−solution−solid growth mechanism was identified to explain the formation of ultrathin Te nanowires. The single-crystalline Te nanowires with an average diameter of 7 nm display strong luminescence emission in the blue-violet region.

To treat or not to treat? Applying chemical engineering tools and a life cycle approach to assessing the level of sustainability of a clean-up technologyElectronic supplementary information (ESI) available: granular activated carbon adsorption. Process design and modelling. See http://www.rsc.org/suppdata/gc/b4/b401871k/

A traditional approach used to evaluate clean-up technologies, in which only plant discharges are considered, is contrasted with a sustainability assessment. The sustainability of any technology can be assessed from three complementary points of view: economic, environmental and social. As such, this paper presents a comprehensive scheme that can be applied to any process, product or technology. In addition, the use of chemical engineering tools such as process design, process modelling and simulation represent a baseline for the sustainability assessment of technologies, as presented in a case study. The optimal granular activated carbon adsorption process design is used as a model system to demonstrate the advantages of sustainability approaches over traditional approaches. A mathematical model that describes the performance of the process at various design options was developed. This model includes cost equations that were used to estimate the total cost of each alternative under different plant designs and two waste scenarios (a benzene and a 1,2-dichloroethane discharge). Life Cycle Assessment tools were applied to generate an inventory of emissions and the impact assessment measured as Photochemical Ozone Creation (POC) and Global Warming Potential (GWP). The model examined trade-offs between pollutants discharged into the atmosphere and pollution associated with the adoption and operation of the technology. One of the main results from the technology assessment is that the environmental impact, measured in terms of GWP proved to be higher for the technology operation than for the untreated waste streams themselves, and therefore suggested that the streams should not be treated. However, the social impact evaluation (measured as risk assessment) conducted as part of this work proved that it was morally and legally mandatory to treat them due to the adverse effects on human health that they may represent. As such, a triple bottom line sustainability assessment was demonstrated to be one of the most important frameworks for decision making. The evaluation scheme presented in this work can also be applied to other areas such as the identification of the most sustainable process design and different green chemistry route alternatives.

Green Chemistry Approaches to the Synthesis of 5-Arylidenethiobarbituric Acids by a Condensation Reactions between Aromatic Aldehydes and Thiobarbituric Acid: Comparison of Water, Microwave Irradiation, and Grinding

A general and practical green chemistry route to the synthesis of 5-arylidenethiobarbituric acids is described from aromatic aldehydes and thiobarbituric acid under three different sets of reaction conditions: water without catalyst conditions, microwave irradiation, and grinding method using NH 4 OAc as a catalyst at room temperature.

Green Chemistry Approaches to the Synthesis of 5‐Alkoxycarbonyl‐4‐aryl‐3,4‐dihydropyrimidin‐2(1H)‐ones by a Three‐Component Coupling of One‐Pot Condensation Reaction: Comparison of Ethanol, Water, and Solvent‐Free Conditions.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Green Chemistry Approaches to the Synthesis of 5-Alkoxycarbonyl-4-aryl-3,4- dihydropyrimidin-2(1H)-ones by a Three-Component Coupling of One-Pot Condensation Reaction: Comparison of Ethanol, Water, and Solvent-free Conditions

A general and practical green chemistry route to the Biginelli cyclocondensation reaction using cerium(III) chloride as the catalyst (25% mol) is described under three different sets of reaction conditions. This method provides an efficient and much improved modification of original Biginelli reaction reported in 1893, in terms of high yields, short reaction times, and simple work-up procedure, and it has the ability to tolerate a wide variety of substitutions in all three components, which is lacking in existing procedures.

Bioreduction of AuCl(4)(-) Ions by the Fungus, Verticillium sp. and Surface Trapping of the Gold Nanoparticles Formed D.M. and S.S. thank the Council of Scientific and Industrial Research (CSIR), Government of India, for financial assistance.

Fungi make piles of gold! A green-chemistry route, based on the bioreduction of AuCl4− ions by the fungus Verticillium sp., for the formation of gold nanoparticles is demonstrated. The TEM micrograph shows a single Verticillium cell after reaction with gold ions and entrapment of gold nanoparticles on the cell wall and cytoplasmic membrane.

The lipolytic effects of β3-adrenoceptor agonist. CL316,243. In isolated rat and human subcutaneous. Mesenteric and epididymal white fat cells

Series of new trigonal bipyramidal and octahedral complexes of tin(IV) have been synthesized by the reaction of dimethyltin(IV) dichloride with 4-nitro-benzanilidethiosemicarbazone (L1H), 4-chlorobenzanilidethiosemicarbazone (L2H), 4-nitrobenzanilidesemicarbazone (L3H) and 4-chlorobenzanilidesemicarbazone (L4H). The unimolecular and bimolecular reactions of dimethyltin(IV) dichloride and monobasic bidentate ligands were carried out using microwave irradiations as the thermal energy source and the complexes so formed were characterized by elemental analysis, conductance measurements, molecular weight determinations and spectral data, viz. IR, UV–vis, 1H and 13C NMR. The complexes have also been prepared by the general thermal methods for comparison purposes. The comparison data support the synthesis using the microwave route, i.e. green chemistry route. The tin(IV) complexes show penta-coordinated structure for 1:1 complexes and hexa-coordinated for 1:2 complexes. The antifungal, antibacterial and antifertility activities have been examined and the results were indeed very encouraging.