Microwave Synthesis Method

Doping is important for semiconductors in order to tune their optical and electrical properties for the potential applications in biotechnology and solar cells [65]. Ag-doped hexagonal CdS nanoparticles were successfully obtained by an ultrasound-assisted microwave synthesis method. Here, the doping of Ag in to CdS nanoparticles induced the evolution of crystal structure from cubic to hexagonal. Further support from photocatalytic experiment also clearly indicates the doping of Ag clusters into the CdS matrix. 

Quite recently [114], the amino acid ionic liquids were synthesized using the one-step microwave synthesis method by using 1-Glu (>99%), 42% HBF4,95-98% H2S04, 65-68% HN03 acid and 37% HC1 ... 

We also developed a novel synthesis method ( in situ aging - microwave synthesis method) for microwave synthesis of zeolite membranes without seeding, which was adapted to the scale-up of the membrane synthesis to integrated supports (e.g. multi-channel tube modules and hollow fibers) [14],... 

Microwave technology as a way to induce rapid heating of solutions has been applied to the crystallization of zeolite phases. Zeolites A, Y, and ZSM-5 can all be prepared under microwave radiation [53,54]. Aliuninophosphate gels which, under normal thermal heating procedures, produce AIPO4-5 were also foimd to produce the same phase under microwave heating [55,56]. Crystal formation was observed as early as 60 seconds after irradiation. The introduction of an additional framework component such as cobalt to produce CoAPO-5 has also been demonstrated utiHzing microwave synthesis methods [57]. 

Ju et al. (2006) carried out microwave synthesis of various azides, thiocyanates, and sulfones in an aqueous medium by reacting alkyl halides or tosylates with alkaU azides, thiocyanates, or sulfinates at 110 C for 20 min in the absence of any phase transfer catalyst, and a variety of reactive functional groups are tolerated. This is a practical, rapid, and efficient microwave synthesis method. 1.3 eq. of alkah azides, thiocyanates, or sulfinates are required to react with alkyl monohalide or alkyl monotosylates to give azides, thiocyanates, and sulfones, respectively. 

Scheme 15 Other microwave-assisted methods for the synthesis of imidazoles...

Scheme 22 Improved microwave-assisted method for the synthesis of 1,2,4-triazines...

The microwave synthesis described in the present paper has proven to be quite eifective due to its intense internal heating, compffl ed to conventional syndesis. The yield of crude VOPc increased with increasing the reaction temperature under both synthetic methods. Fine crystal VOPc was prepared successfiiUy from the crude VOPc obtained by microwave synthesis through the acid-treatment and recrystallization step. 

In this study we show that the Pd/C catalyzed Suzuki-Miyaura coupling reaction can be performed in a microwave oven. Overall the microwave synthesis is faster than comparable thermal methods and the combination of the ease of use of the microwave oven and the facile work-up with Pd/C makes this a very efficient method for performing coupling reactions. 

Studies on the use of hydrothermal, microwave-assisted, and reflux synthesis methods for the development and application of nanomaterials have been reviewed. An important aspect of the green synthesis of metallic nanopartides involves techniques that make use of biological materials such as plant extracts and microorganisms. The design of nanomaterials and control of their desired properties have been reviewed. The unique properties of manufactured nanomaterials offer many potential benefits. 

Microwave processing of zeolites and their application in the catalysis of synthetic organic reactions has recently been excellently reviewed by Cundy [23] and other authors [24], The microwave synthesis of zeolites and mesoporous materials was surveyed, with emphasis on those aspects which differ from conventional thermal methods. The observed rate enhancement of microwave-mediated organic synthesis... 

The palladium-catalyzed Heck carbonylation reaction is a powerful means of generating amides, esters, and carboxylic acids from aryl halides or pseudohalides [28]. The development of rapid, reliable, and convenient procedures for the introduction of carbonyl groups is important for the development of high throughput chemistry in general and high-speed microwave-mediated chemistry in particular. Unfortunately, the traditional method of introducing carbon monoxide into a reaction mixture via a balloon or gas tube is not practical because of the special requirements of microwave synthesis. 

You should consider the availability of reactants required for a particular method. If you are considering a precursor method, is there a suitable precursor with the right stoichiometry The CVD method needs reactants of similar volatility do your proposed reactants meet this requirement In microwave synthesis, does at least one of your starting materials absorb microwaves strongly ... 

Perez, R., Perez, E.R., Suarez, M., Gonzalez, L., Loupy, A. et al, Synthesis of aminotoluenesulfonamide derivatives using conventional heating or microwave-assisted methods, Org. Prep. Proced. Int., 1997, 29, 671. 

A number of cationic lipids have been prepared using solid-phase methods [147— 159]. Along with the well-known advantages that solid-phase chemistry provide (e.g. mass action, simple purification, compatibility with microwave synthesis [ 160, 161]), the main reason to use this approach is that it facilitates parallel synthesis of libraries of compounds, allowing potential structure activity relationships to be rapidly determined by the systematic modification of the cationic lipid structure per domain. 

A more recently published example of organic microwave synthesis under CF conditions is the 1,3-dipolar cycloaddition chemistry in the CEM CF Voyager system (Fig. 11). Savin and coworkers presented the cycloaddition of dimethyl acetylene dicarboxylate with benzyl azide in toluene, which was first carefully optimized with respect to solvent, temperature, and time under batch conditions. The best protocol was then translated to a CF procedure where a 0.33 M solution of both building blocks was pumped through a Kevlar-enforced Teflon coil (10 mL total capacity) heated in the single-mode reactor at 110 °C (10 min residence time) [66]. This method provided a 91% conversion to the desired triazole product (Scheme 12). 

Many of the traditional methods continue to be exploited to synthesise novel materials. In the area of cuprates, the synthesis of a superconducting ladder cuprate and of car-bonato- and halocuprates is noteworthy. High pressure methods have been particularly useful in the synthesis of certain cuprates and other materials.36,44 The combustion method has come of age for the synthesis of oxidic and other materials.45 Microwave synthesis is becoming popular46 while sonochemistry has begun to be exploited.47... 

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