Construction of multicomponent

The extension of this approach to artificial leaves based on titanates, niobates, tantalates, metal nitrides and phosphides, metal sulfides, and other transition metal oxides appears possible and useful in order to enhance the photocatalytic efficiency. In addition, the construction of multicomponent systems such as Ti02-CdS or MoS2-CdSe for overall water splitting could also lead to further improvements. This... 

In conclusion, the potential of soluble, nanosized metallodendrimers as catalysts in homogeneous reactions is well-consolidated. Future applications of these species are foreseen in high-tech nanotechnology applications in the fields of nano- and microreactors, cascade catalysis, and catalytic biomonitoring and biosensing. In this respect, the recent use of noncovalent strategies for the construction of multicomponent catalytic assemblies, and the use of biomacromolecules within dendritic structures is intriguing [60-62,92,93]. 

Spinke J, Liley M, Guder H J, Angermaier L and Knoll W 1993 Molecular recognition at self-assembled monolayers—the construction of multicomponent multilayers Langmuir 9 1821-5... 

NBr+), whereas complementary compounds 3 and 6 comprise negatively charged NDl side chains with glutamine residues (NBr-). Complementary topology of the compounds allowed for construction of multicomponent assemblies such as Au-1-2-3-2 (OPE scaffold) and Au-4-5-6-5 (POP scaffold) (Figure 28). 

Rojas-Hernandez A, Ramirez MT, Ibanez JG, Gonzalez I (1991) Construction of multicomponent Pourbaix diagrams using generalized species. J Electrochem Soc 138 365-371. doi 10.1149/ 1.2085590... 

Construction of one-dimensional multicomponent molecular arrays, transition metal complexes with terpyridines and/or porphyrins as ligands 98EJI1. 

The majority of polyamides used commercially are nylon-6,6 or nylon-6. The largest supply of waste for recycling of nylons is obtained from used carpets. Approximately 30-40% of die nylon produced in the world is used as carpet face fibers.1 Carpets consist of a multicomponent construction of face fibers and a primary and secondary backing. The face fibers are generally made of... 

It should be mentioned here that the self-assembly of native proteins may also be effective in the construction of inorganic-organic multicomponent structures, as demonstrated by the biominerlization processes [17]. 

Mitchell, M. C., Spikmans, V., Bessoth, F., Manz, a., de Mello, A., Towards organic synthesis in microfluidic devices multicomponent reactions for the construction of compound libraries, in van den Berg, A., Olthuis, W., Bergveld,... 

The application of NMR to the study of chemical reactions has been expanded to a wide range of experimental conditions, including high pressure and temperatures. In 1993, Funahashi et al. [16] reported the construction of a high pressure 3H NMR probe for stopped-flow measurements at pressures <200 MPa. In the last decade, commercial flow NMR instrumentation and probes have been developed. Currently there are commercially available NMR probes for pressures of 0.1-35 MPa and temperatures of 270-350 K (Bruker) and 0.1-3.0 MPa and 270-400 K (Varian). As reported recently, such probes can be used to perform quantitative studies of complicated reacting multicomponent mixtures [17]. 

Another frequently used multicomponent reaction is the Kindler thioamide synthesis (the condensation of an aldehyde, an amine, and sulfur). The Kappe group has described a microwave-assisted protocol utilizing a diverse selection of 13 aldehyde and 12 amine precursors in the construction of a representative 34-member library of substituted thioamides (Scheme 6.114) [226]. The three-component con-... 

Mass spectrometers have been used at some level in all of these types of investigations because of their unsurpassed sensitivity and specificity, their multicomponent analytical capability and, in some cases, their ability to provide precise and accurate isotope ratios. Traditional methods of analysis typically involve the collection of water and sediment samples, or biological specimens, during field expeditions and cmises on research vessels (R/Vs), and subsequent delivery of samples to a shore-based laboratory for mass spectrometric analyses. The recent development of field-portable mass spectrometers, however, has greatly facilitated prompt shipboard analyses. Further adaptation of portable mass spectrometer technology has also led to construction of submersible instruments that can be deployed at depth for in situ measurements. 

In asymmetric catalysis, Sharpless emphasized the importance of ligand-accelerated catalysis through the construction of an asymmetric catalyst from an achiral precatalyst via ligand exchange with a chiral ligand. By contrast, a dynamic combinatorial approach, where an achiral precatalyst combined with several multicomponent chiral ligands (L, -----) and several chiral activator ligands... 

Two different methods have been presented in this contribution for correlation and/or prediction of phase equilibria in ternary or mul> ticomponent systems. The first method, the clinogonial projection, has one disadvantage it is not based on concrete concepts of the system but assumes, to a certain extent, additivity of the properties of individiial components and attempts to express deviations from additivity of the properties of individual components and attempts to express deviations from additivity by using geometrical constructions. Hence this method, although simple and quick, needs not necessarily yield correct results in all the cases. For this reason, the other method based on the thermodynamic description of phase equilibria, reliably describes the behaviour of the system. Of cource, the theory of concentrated ionic solutions does not permit a priori calculation of the behaviour of the system from the thermodynamic properties of pure components however, if a satisfactory equation is obtained from the theory and is modified to express concrete systems by using few adjustable parameters, the results thus obtained are still substantially more reliable than results correlated merely on the basis of geometric similarity. Both of the methods shown here can be easily adapted for the description of multicomponent systems. 

Nair V, Vinod AU, Abhilash N et al (2003) Multicomponent reactions involving zwitterionic intermediates for the construction of heterocyclic systems one pot synthesis of aminofurans and iminolactones. Tetrahedron 59(51) 10279-10286... 

This sequence has been successfully extended to the regioselective multicomponent construction of bis- pyrano-l,4-benzoquinone derivatives when unsubstituted 2,5-dihydroxy-l,4-benzoquinone is used (Scheme 39) [130], Depending on the alkene moiety, the reaction yielded only the linear tri-, penta-, or heptacyclic product in a 1 1 diasteromeric ratio, as illustrated with indene. 

This simple sketch illustrates clearly that convergent multicomponent reactions performed with a limited set of reactive building blocks (reactophores) in a multigeneration format offer a tremendous potential to produce diverse small-molecule compound collections, depending on the reaction sequence used (the combinatorics of reactive building blocks ). The concept of combinatorics of reactive building blocks should ultimately lead to novel multicomponent reactions. In Section III we will focus on reactophores such as a-alkynyl ketones, which allow the construction of a wide variety of core structures. 

The second article also deals with PET in arranged media, however, this time by discussing comprehensively the various types of heterogeneous devices which may control supramolecular interactions and consequently chemical reactions. Before turning to such applications, photosynthetic model systems, mainly of the triad type, are dealt with in the third contribution. Here, the natural photosynthetic electron transfer process is briefly discussed as far as it is needed as a basis for the main part, namely the description of artificial multicomponent molecules for mimicking photosynthesis. In addition to the goal to learn more about natural photosynthetic energy conversion, these model systems may also have applications, which, for example, lie in the construction of electronic devices at the molecular level. 

Multicomponent reactions (MCRs) have high efficiency in the construction of complex molecules [39,40]. In general practice, more than one reagent is used in excess to push the reaction to go to completion. The unreacted components left in the reaction mixture may complicate the product purification. The employment of a fluorous component as the limiting agent for the MCRs is a good way to simplify the purification. 

Some representative examples of fullerene-porphyrin dyads are shown in Scheme 9. In other examples, porphyrin analogs such as phthalocyanines and subphthalocyanines have been used for the construction of efficient dyads. Again, the most straightforward approach for their synthesis involved 1,3-dipolar cycloaddition of the appropriate azomethine ylides to C60 [203-205]. Also, with the aid of the Bingel reaction, other phthalocyanine-fullerene systems have been prepared [206,207] with the most prominent example being the one that contains a flexible linker possessing an azacrown subunit [208]. The novelty of this dyad can be found in the nature of the linker that could, in principle, induce conformational changes in the multicomponent system when certain ions (e.g., alkaline ions) are present. As a direct consequence this would potentially allow an external control over the electronic interactions between the phthalocyanine and fullerene units. 

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