Terphenyls and derivatives

Terphenyls and Derivatives. p-Terphenyl can be prepared satisfactorily in two ways (a) from the nitrosoacetyl derivative of 4-aminobi-phenyl, and (6) from the bis-nitrosoacetyl derivative of p-phenylenedi-amine. The yields by both routes are about the same (50-60%). 

Goulding, M. G., Greenfield, S., Coates, D., and Clemitson, R., Lateral fluoro substituted 4-alkyl-4"-chloro-l,l 4, l"-terphenyls and derivatives. Useful high birefringence, high stability liquid crystals, liq. Cryst, 14, 1397, 1993. 

Biphenyl, terphenyl, and their alkyl or hydrogenated derivatives generally serve markets where price and performance, rather than composition, is the customer s primary concern. Performance standards for heat-transfer appHcations are usually set by the fluid suppHer. The biphenyl—diphenyl oxide eutectic (26.5% biphenyl, 73.5% DPO) represents a special case. This composition has become a widely recogni2ed standard vapor-phase heat-transfer medium. It is sold throughout the world under various trademarks. In the United States, Dow (Dowtherm A) and Monsanto (Therminol VP-1) are the primary suppHers. Alkylated biphenyls and partially hydrogenated terphenyls serving the dielectric and carbonless copy paper dye solvent markets likewise are sold primarily on the basis of price and performance characteristics jointly agreed on by producer and user. 

Hexa(oligophenyl)benzenes (e. g. 31 or 33) present one possible approach to the realization of this aim. Two efficient synthetic routes have been elaborated for the preparation of hexa(terphenyl)- and hexa(quaterphenyl)benzene. The first, involving palladium-catalyzed trimerization of diarylacetylenes [54] as the key step, was demonstrated by the synthesis of a hexakis-alkylated hexa(terphenyl)benzene derivative 31 from the corresponding bis(terphenyl) acetylene (32). The peripheral tert-alkyl substituents serve to solubilize the molecule. 

Lerom, M. W. et al., J. Chem. Eng. Data, 1974, 19, 389-392 Several difluoroaminopolynitro derivatives of stilbene, biphenyl, terphenyl and their precursors are explosives, sensitive to initiation by impact, shock, friction or rapid heating. 

Although many hydrocarbons exhibit fluorescence, often they are colourless and the fluorescence is only just into the blue, e.g. the linear terphenyl and quaterphenyl. Polycyclic ring systems such as terrylene and rubicene are used in analytical methods and OLEDs but a large number are ruled out of commercial use because of their potential to act as carcinogens. However, as mentioned in section 3.5.1.3, pery-lene is a useful fluorophore in a variety of outlets and pyrene is another polycyclic compound of interest. One derivative of pyrene (3.27) is a yellow-green fluorescent dye used in textile applications (Cl Solvent Green 7) and in analysis and sensors (see section 3.5.6.4). 

The 1,3,4-oxadiazole system has an electronic spectrum equivalent to that of benzene and the maxima of the oxadiazole derivatives are only slightly shifted hypsochromically compared with benzene.103 Thus, for example, diphenyl and 2-phenyl-l,3,4-oxadiazole absorb almost identically at 248 ra.fi and p-terphenyl and 2,5-diphenyl-l,3,4-oxadiazole absorb at 276 and 280 mfi, respectively.103 The oxadiazole system is effective in the conjugative transmission of the effects of substituents.103 An extension of the system of conjugated rt bonds... 

The shock against benzene produced H2, light alkanes from Ci to C3, light alkenes from C2 to C3, C2H2, and aromatic hydrocarbons witli molecular weights ranging from 102 (phenylacetylene) to 306 (quaterphenyl). Tliis reaction produced H2, CH4, polyphenyl compounds such as biphenyl, terphenyl, and quaterphenyl. Otlier major products were naphthalene, fluorene, trans-stilbene, phe-nanthrene, isomers of phenylnaphthalene and chrysene. The shock produced ethenyl in greater abundance than etliyl derivatives. 

Fig. 23 Nonpeptidic helix mimetics such as (b) terphenyls and (c) pyridylpyridone derivatives array protein like functionality to mimic their arrangement on an a-helix (a) (Reprinted from Guarracino et al. [148], Copyright (2011) with permission from Wiley)...

Various templates, 98-105, were readily synthesized from the corresponding internally substituted 4,4 -dimethyl-m-terphenyls and employed in the synthesis of macrocycles of general structure 5. The bis-bromomethyl derivatives 98-101 [15] were obtained in good yields by the direct NBS bromination of the methyl groups. The conversion to the corresponding bis-mercaptomethyl compounds 102-11 [15] was carried out via the respective isothiouronium intermediates and were obtained in acceptable yields. 

Additives have been developed to improve the cathode cyclability performance of lithium batteries (33). Benzene derivatives (biphenyl and o-terphenyl) and heterocyclic compounds (furan, thiophene, N-methylpyrrole and 3,4-ethylenedioxythiophene), which have lower oxidation potentials than those of electrolyte solvents have been tested. The functional electrolytes used are shown in Figure 2.4. 

Biphenyl and mixed terphenyls as weU as their normally Hquid alkyl and partially hydrogenated derivatives are commonly stored in the Hquid or molten state. The products are noncorrosive mild steel equipment usually suffices for handling. 

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