Continuous interest

Studies of surfaces and surface properties can be traced to the early 1800s [1]. Processes that involved surfaces and surface chemistry, such as heterogeneous catalysis and Daguerre photography, were first discovered at that time. Since then, there has been a continual interest in catalysis, corrosion and other chemical reactions that involve surfaces. The modem era of surface science began in the late 1950s, when instmmentation that could be used to investigate surface processes on the molecular level started to become available. 

Secondly, the ultimate properties of polymers are of continuous interest. Ultimate properties are the properties of ideal, defect free, structures. So far, for polymer crystals the ultimate elastic modulus and the ultimate tensile strength have not been calculated at an appropriate level. In particular, convergence as a function of basis set size has not been demonstrated, and most calculations have been applied to a single isolated chain rather than a three-dimensional polymer crystal. Using the Car-Parrinello method, we have been able to achieve basis set convergence for the elastic modulus of a three-dimensional infinite polyethylene crystal. These results will also be fliscussed. 

New lonomer Types. There is a continuing interest in new ionomers within the academic community, since novel and unexpected phenomena are frequently being discovered. However, there are still many unanswered questions with respect to the ethylene ionomers, especially the influence of ionic bonding on crystalline stmcture. Continued study of these interesting polymers will close the gaps in knowledge of this area of polymer science. 

Replacing one carbon atom of naphthalene with an a2omethene linkage creates the isomeric heterocycles 1- and 2-a2anaphthalene. Better known by their trivial names quinoline [91-22-5] (1) and isoquinoline [119-65-3] (2), these compounds have been the subject of extensive investigation since their extraction from coal tar in the nineteenth century. The variety of studies cover fields as diverse as molecular orbital theory and corrosion prevention. There is also a vast patent Hterature. The best assurance of continuing interest is the frequency with which quinoline and isoquinoline stmctures occur in alkaloids (qv) and pharmaceuticals (qv), for example, quinine [130-95-0] and morphine [57-27-2] (see Alkaloids). 

The mechanisms of formation of oxiranes by biological systems (which are relevant to carcinogenesis — see the penultimate paragraph) are the subject of continuing interest <81JA6744. 81JA7371). 

There is continuous interest in cleavage of epoxides as a general method lor the preparation of fluorohydrins Epoxides are effectively cleaved under mild conditions by a 70% hydrogen fluoride-pyridine complex (Olah s reagent). The... 

The editor wishes to extend his thanks to each of the contributors of this book who so willingly gave of their time and talents, and he wishes to extend his personal gratitude to Dr. Nelson J. Leonard for initially stimulating his interest in enamines and for his continuing interest over the years. 

The apparent inertness of the noble gases gave them a key position in the electronic theories of valency as developed by G. N. Lewis (1916) and W. Kossel (1916) and the attainment of a stable octet was regarded as a prime criterion for bond formation between atoms (p. 21). Their monatomic, non-polar nature makes them the most nearly perfect gases known, and has led to continuous interest in their physical properties. 

This is undoubtedly the most prolific oxidation state for this group of elements. The stereochemistry of Ni" has been a topic of continuing interest (see Panel), and kinetic and mechanistic studies on complexes of Pd" and Pt" have likewise been of major importance. It will be convenient to treat Ni" complexes first and then those of Pd" and Pt"... 

In spite of long and continued interest in the reactions to be described, there has been relatively little work on the reaction... 

In recent years there has been a continued interest in the use of alkali metals, notably sodium and lithium, as heat exchange media in nuclear reactors and fusion systems respectively and as chemical reactants in fuel cells. This interest is reflected in the proceedings of several major conferences which are referenced in the bibliography (see p. 2.109). 

Improved reliability of equipment, but much still to be done Maintenance costs often too high Desire to go more automatic and on-line Awareness that system installation is expensive Continuing interest in new techniques... 

Since the realization in the early 1980s that poly (ethylene oxide) could serve as a lithium-ion conductor in lithium batteries, there has been continued interest in polymer electrolyte batteries. Conceptually, the electrolyte layer could be made very thin (5im ) and so provide higher energy density. Fauteux et al. [31] have recently reviewed the present state of polymer elec-... 

It is a particular pleasure to thank the institutions which provided financial support to this work. These are the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie, and the Bund der Freunde der Technischen Universitat Miinchen. I am also indebted to Professor H. Schmidbaur, Garching, for his continued interest in our investigations, to Professor G. Muller, Konstanz, for the x-ray structure determinations and to Professor G. Bowmaker, who was on sabbatical leave from Auckland, New Zealand, for critical reading of the manuscript. 

Metal complexes of 1,1-dithiolates have been reviewed by Coucou-vanis (1) Eisenberg (2) presented a systematic, structural review of dithiolato chelates, and Stokolosa ct al. (3) reviewed dithiophosphate complexes in detail. Earlier reviews (4-3) covered less recent work in greater detail. Following initial work by Delepine (9), 1,1-dithiolato complexes were more intensively studied between 1930 and 1941 (10-16). There is, however, continuous interest in the synthesis, characterization, electronic structures, and bonding of these complexes. 

In connection with our continuing interest in the temperature bromination reactions (ref. 2) we have been interested in the bromination reactions of benzonorbornadiene 1 and benzobarrelene 2. 

The Dow Chemical Company has maintained a continuing interest in the safe handling of chemicals, particularly those whose reactivity makes them useful monomers for commercial polymers. The thermal reactions of 4,4 -diisocyanatodiphenylmethane have been investigated as part of this program. 

There is a continuing interest in the development of biomarker assays for use in environmental risk assessment. As discussed elsewhere (Section 16.6), there are both scientific and ethical reasons for seeking to introduce in vitro assays into protocols for the regulatory testing of chemicals. Animal welfare organizations would like to see the replacement of toxicity tests by more animal-friendly alternatives for all types of risk assessment—whether for environmental risks or for human health. 

The intriguing structural complexity and often potent biological activity exhibited by many polyacetate-derived natural products have generated a continuing interest in the development of efficient, stereoselective approaches to the assembly of repeating l -diol subunits. One such method is the alkylation and reduc-... 

Nanosize particles (e.g., metals, semiconductors, etc.) are of continuing interest because they possess fascinating catalytic, electronic, and optical properties. Larger particles decorated with smaller nanoparticles on their surface are of interest because of their potential use as heterogeneous catalysts and their relevance in electronic and optical sensor applications as well as surface-enhanced Raman scattering [39,72-75]. 

For nearly two decades TACN-type ligands are of continuing interest for oxidation chemistry. A more recent example is described by ShuFpin and cow-orkers, who prepared novel di- and tetranuclear complexes with TACN ligands 25 bearing pendant acetato arms bridging the iron(lll) centers (Scheme 18) [111]. The... 

In parallel with the identification of distinct transporters for GABA there has been continued interest in the development of selective blockers of these transporters and the therapeutic potential that could result from prolonging the action of synaptically released GABA. It has been known for a long time that certain pro-drugs of nipecotic add (e.g. nipecotic acid ethyl ester) are able to cross the blood-brain barrier and are effective anticonvulsants in experimental models of epilepsy. More recently, several different systemically active lipophillic compounds have been described that act selectively on GAT-1, GAT-2 or GAT-3 (Fig. 11.4). Of these, tiagabine (gabitiil), a derivative of nipecotic acid that acts preferentially on GAT -1, has proved clinically useful in cases of refractory epilepsy. 

---