Property types derived

The covalent chemistry of fullerenes has developed very rapidly in the past decade in an effort to modify fuUerene properties for a number of applications such as photovoltaic cells, infrared detectors, optical limiting devices, chemical gas sensors, three-dimensional electroactive polymers, and molecular wires [8, 25, 26, 80-82]. Systematic studies of the redox properties of Cgo derivatives have played a crucial role in the characterization of their unique electronic properties, which lie at the center of these potential applications. Furthermore, electrochemical techniques have been used to synthesize and separate new fullerene derivatives and their isomers as well as to prepare fullerene containing thin films and polymers. In this section, to facilitate discussion of their redox properties, Cgo derivatives have been classified in three groups on the basis of the type of attachment of the addend to the fullerene. In group one, the addends are attached via single bonds to the Cgo surface as shown in Fig. 6(a) and are referred to as singly bonded functionalized derivatives. The group includes... 

Another type of intrinsic property is derived from the theory of light scattering in particles. The phenomenon of Raman and fluorescent scattering from molecules suspended in small dielectric particles exemplifies such prop-... 

Subsequently, workers in pharmaceutically related fields realized that the solid-state property differences derived from the existence of alternate crystal forms could translate into measurable differences in properties of pharmaceutical importance. For instance, it was found that various polymorphs could exhibit different solubilities and dissolution rates, and these differences sometimes led to the existence of nonequivalent bioavailabilities for the different forms. Since then, it has become recognized that an evaluation of the possible polymorphism available to a drug substance must be thoroughly investigated early during the stages of development. In various compilations, it has been reported that polymorphic species are known for most drug substances and that one should be surprised to encounter a compound for which only one structural type can be formed. 

Along these lines, we want to highlight the recent advances that have been made in the synthesis and characterization of poly(2,7-carbazole)s and related polymers. The synthesis of ladder-type derivatives with extended n systems like indolo[3,2-fr] carbazoles, diindolo[ 3,2-fr 2, 3 -fz ] carbazoles, and bisindenocarbazoles will also be presented. The structure-property relationships of all these materials will be discussed as well as their utilization as active layers in several organic electronic devices, such as light-emitting diodes (LEDs), field-effect transistors (FETs), photovoltaic cells (PCs), and thermoelectric devices (TDs). 

In the majority of cases, chemical additives are used to enhance the properties of base oils to improve such characteristics as oxidation resistance (ASTM D-2893, ASTM D-4742,ASTM D-5846) change in viscosity (ASTM D-445, IP 71) with temperature, low-temperature flow properties as derived from the pour point (ASTM D-97, ASTM D-5853, ASTM D-5949, ASTM D-5950, ASTM D-5985, IP 15) and fluidity measurements (ASTM D-6351), emulsifying ability (ASTM D-2711), extreme pressure (ASTM D-2782, ASTM D-2783, ASTM D-3233, IP 240), antiwear and frictional properties (ASTM D-5183, ASTM D-6425), and corrosion resistance (ASTM D-4636). The selection of components for lubricating oil formulation requires knowledge of the most suitable crude sources for the base oils, the type of refining required, the types of additive necessary, and the possible effects of the interactions of these components on the properties of the finished lubricating oil. 

As mentioned in the introduction, metallocene-type complexes based on the early transition metals were evaluated as anticancer compounds shortly after the discovery of cisplatin. While the biological activity of each of the metallocene dihalides is unique, titanocene dichloride 7 has been the subject of a number of studies and even entered clinical evaluation, although evaluation was discontinued (not due to its anti-proliferative properties), principally due to formulation problems, despite showing superior activity to certain cancers than other established drugs. This class of compound continues to be modified and studied for anticancer activity, for example, the titanocene-type derivative of tamoxifen 1, described above, and other developments described below. 

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