Novel Systems

In this section, we describe the stereochemistry of a small group of species with nontra-ditional or unexpected structures. Classification of these species has a certain amount of arbitrariness. 

Collman et al. have described the preparation and characterization of a binuclear porphyrin complex containing a Ru-Ru metal-metal bond of order two. The Ru-Ru bond length in [Ru(OEP)]2 is 2.408(1) A. The average Ru-Np bond distance is 2.050(5) A. The two porphinato planes are twisted 24° with respect to each other. This derivative is the only one with metal-metal bonded porphyrin units structurally characterized. 

The structure of seven-coordinate [Nb2(TPP)203] and [Nb(TPP)(0Ac)(0)] and six-coordinate [Nb(0EP)(F)(0)] are all found to have all axial ligand on the same side of the porphyrin plane ina4-l-3or4-f2 arrangement. The niobium(V) ion is displaced out of the porphyrin nitrogen atom plane by 0.9-1.0 A and the Nb-Np distances are 2.21 to 2.24 A. 

The first six-coordinate zinc(II) porphyrinate complex has been reported. [Zn(TPP)(THF)2] has two axial THF ligands at Zn-O = 2.380(2) A. The Zn-Np distance is 2.057(1) A. As described later, we think that this compound is stabilized by solid state factors. We have also recently found a six-coordinate zinc(II) complex, again solid state factor appear responsible for the unusual coordination number. 

Buchler, Weiss and coworkers have recently described the structures of lanthanide porphyrins. The structures of cerium(IV) doubledecker and biscerium(III) tripledecker molecules have been described [Ce(OEP)2] and [Ce2(OEP)3] have cerium ions with approximate square-antiprismatic geometry in both complexes. In the double-decker complex, the Ce-Np bond length is 2.475(1) A. The two porphyrin rings are rotated by about 43° with respect to each other. A quite similar structure is seen for [Eu(OEP)2] . In this structure, Eu-Np is slightly longer at 2.510(2) A. The two rings 

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CAMUS - A Novel System for Operator Based Ultrasonic Weld Inspection. 

This paper describes the development of a novel system for improving the quality of information provided by manual ultrasonic examination of welds, while retaining the flexibility of the human operator to apply the techniques to components of a wide range of geometries and dimensions. The system, known as CamuS (Computer Aided Manual UltraSonics) provides assistance to the manual operator in two separate areas ... 

The investigation of the photochemistry of steroidal cross-conjugated dienones was initiated by both Barton and Jeger and was pursued most extensively by the latter group. Despite the frequently complex product patterns which result from prolonged dienone irradiations, some prepara-tively convenient and useful methods for the synthesis of novel systems have been worked out in this field. 

The second major discovery regarding the use of MTO as an epoxidation catalyst came in 1996, when Sharpless and coworkers reported on the use of substoichio-metric amounts of pyridine as a co-catalyst in the system [103]. A change of solvent from tert-butanol to dichloromethane and the introduction of 12 mol% of pyridine even allowed the synthesis of very sensitive epoxides with aqueous hydrogen peroxide as the terminal oxidant. A significant rate acceleration was also observed for the epoxidation reaction performed in the presence of pyridine. This discovery was the first example of an efficient MTO-based system for epoxidation under neutral to basic conditions. Under these conditions the detrimental acid-induced decomposition of the epoxide is effectively avoided. With this novel system, a variety of... 

Barr AM, Kinney JW, Hill MN et al (2006) A novel, systemically active, selective galanin receptor type-3 ligand exhibits antidepressant-like activity in preclinical tests. Neurosci Lett 405 111-115... 

This latter point was stressed by some of us in a recent report studying NO storage and reduction on commercial LSR (lean storage-reduction) catalysts, in order to catch valuable information about the behaviour of typical NO storage materials in real application conditions. Nature, thermal stability and relative amounts of the surface species formed on a commercial catalyst upon NO and 02 adsorption in the presence and in the absence of water were analysed using a novel system consisting of a quartz infrared reactor. Operando IR plus MS measurements showed that carbonates present in the fresh catalyst are removed by replacement with barium nitrate species after the first nitration of the material. Nitrate species coordinated to different barium sites are the predominant surface species under dry and wet conditions. The difference in the species stabilities suggested that barium sites possess different basicity and, therefore, that they are able to stabilize nitrates at different temperatures. At temperatures below 523 K, nitrite species were observed. The presence of water at mild temperatures in the reactant flow makes unavailable for NO adsorption the alumina sites [181]. 

Freifield B., Trautz R., et al. The U-tube a novel system for acquiring borehole fluid samples from a deep geologic C02 sequestration experiment. 2005 Journal of Geophysics Reservoir 110 B10203. 

Hatakeyama H, Akita H, Kogure K, Oishi M, Nagasaki Y, Kihira Y, Ueno M, Kobayashi H, Kikuchi H, Harashima H (2007) Development of a novel systemic gene delivery system for cancer therapy with a tumor-specific cleavable PEG-lipid. Gene Ther 14 68-77... 

Suter, M., and Butler, J.E. (1986) The immunochemistry of sandwich ELISAs. II. A novel system prevents the denaturation of capture antibodies. Immunol. Lett. 13, 313-316. 

A Novel System for the Application of Bromine in Flame-Retarding Polymers... 

A variety of functionalities, tether lengths, and alkene substitution patterns were tolerated (Equation (35)).52,53 Of particular significance is the synthesis of a-methylene-y-butyrolactone 55, as only Zhang had reported successfully using Alder-ene chemistry to gain access to this novel system (see Section 10.12.4.3). The reaction was sensitive to the length of the tether, since there was a marked decrease in yield for the formation of the six- and seven-membered carbocycles (53 and 54, respectively) compared to the five-membered case 52. 

Freifeld, B.M., Trautz, R.C., Yousif K.K., Phelps, T.J., Myer, L.R., Hovorka, S.D., Collins, D. 2005. The U-Tube A novel system for acquiring borehole fluid samples from a deep geologic CO2 sequestration experiment. Journal Geophysical Research, 110, B10203, doi 10.1029/2005JB003735. 

The SEA approach can be applied to a novel system in three steps (1) measure the PZC of the oxide (or carbon) and choose a metal cation for low-PZC materials and an anion for high-PZC materials, (2) perform an uptake-pH survey to determine the pH of the strongest interaction in the appropriate pH regime (high pH for low PZC and vice versa), and (3) tune the calcination/reduction steps to maintain high dispersion. Highly dispersed Pt materials have been prepared in this way over silica, alumina, and carbon. Other oxides can be employed similarly. For bimetallics, the idea is to first adsorb a well-dispersed metal that forms an oxide intermediate with a PZC very different to the support. In this way the second metal can be directed onto the first metal oxide by SEA. Reduction may then result in relatively homogeneous bimetallic particles. 

Cabrera and co-workers [28] reported the first combinations of monolithic columns (50 mm x 4.6 mm and 100 mm x 4.6 mm) and mass spectrometry detection, a novel system configuration able to demonstrate a doubling of throughput by using increased flow rates while also maintaining separation efficiency. 

The central topic of the book was the integration of microhotplate-based metal-oxide gas sensors with the associated circuitry to arrive at single-chip systems. Innovative microhotplate designs, dedicated post-CMOS micromachining steps, and novel system architectures have been developed to reach this goal. The book includes a multitude of building blocks for an application-specific sensor system design based on a modular approach. 

Ionic liquids are, quite simply, liquids that are composed entirely of ions. Thus, molten sodium chloride is an ionic liquid a solution of sodium chloride in water (a molecular solvent) is an ionic solution. The term ionic liquids was selected with care, as it is our belief that the more commonly used phrase molten salts (or simply melts) is referential, and invokes a flawed image of these solvents as being high-temperature, corrosive, viscous media (cf. molten cryolite). The reality is that room-temperature ionic liquids can be liquid at temperatures as low as — 96°C, and are typically colorless, fluid, and easily handled. To use the term molten salts to describe these novel systems is as archaic as describing a car as a horseless carriage. Moreover, in the patent and recent academic literature, ionic... 

Appropriate barrier methods and vaginal formulations are the first line of defense against the prevention of pregnancy and STDs. Recognition of this fact and initiation of work to develop traly novel systems should be a major development focus. Indeed, major efforts are under way to develop new and more effective microbiocides, excipient delivery vehicles, and subsequent formulations. 

Chan, H-K., Daviskas, E., Eberl, S., Robinson, M., Bautovich, G., and Young, I.H., Deposition of aqueous aerosol of technetium-99m diethylenetriamine pentaacetic acid generated and delivered by a novel system (AERx) in healthy subjects, Eur. J. Nucl. Med., 26 320-327 (1999). 

It should be emphasized that the wide scope of nucleophilic aromatic photosubstitution does not imply that it will work indiscriminately with any combination of aromatic compound and nucleophile. On the contrary, there are pronounced selectivities. The general picture now arising shows a field with certainly as much variability and diversification as chemists, in the course of growing experience, have learned to appreciate in the area of classical (thermal) aromatic substitution. It is one of the aims of this article to contribute to a description and understanding of the various reaction paths and mechanisms of nucleophilic aromatic photosubstitution, hopefully to the extent that valuable predictions on the outcome of the reaction in novel systems will become feasible. 

Imine metathesis has continued to be a popular exchange reaction for DCLs. Various groups have found novel systems in which the reaction can be applied, as well as interesting ways to halt the equilibration. For example, Wessjohann and coworkers have demonstrated that Ugi reactions can efficiently halt equilibration of an imine DCL, combining an irreversible diversification process with areversible library selection [24]. Xu and Giusep-pone have integrated reversible imine formation with a self-duplication process [25], and Ziach and Jurczak have examined the ability of ions to template the synthesis of complex azamacrocycles [26]. The mechanistically related reactions of hydrazone [27] and oxime [28] exchange have also been explored as suitable foundations for DCL experiments. 

E. J. Casey (Defense Research Establishment, Ottawa) reviewed the selection of anodes and electrolytes for high-energy density storage batteries. The present state of development of batteries by using light metal anodes in nonaqueous, molten salt and solid electrolytes was reviewed, and suggestions were made on the feasibility of novel systems. 

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