Oligo s

Figure 14.15 Major types of modification potentially made to an oligo s phosphodiester linkage in order to increase their stability or enhance some other functional characteristic. The native phosphodiester link is shown to the left...

Figure 8.11 Proposed chain-elongation mechanism via the formation of racemic antiparallel (ap) 6-sheets comprising alternating oligo-R and oligo-S chains, both with the enantiopure initiator S-Phe-OMe, ft, at their C terminus, as modeled on the basis of...

Lendlein and Langer (2002) demonstrated this concept using multiblock copolymers based on hard segments of crystallizable oligo(p-dioxanone) diol and switching segments of oligo(s-caprolactone)diol. Fibres of this... 

Pale-Grosdemange C, Simon E S, Prime K L and Whitesides G M 1991 Formation of self-assembled monolayers by ohemisorption of derivatives of oligo(ethylene glyool) of struoture FIS(CFl2),, (OCFl2CFl2)meta-OFI on gold J. Am. Chem. Soc. 113 12-20... 

By the reaction of bromotoluene with ethylene under pressure, p-methylsty-rene and stilbene (45) are obtained[44,45]. A polymer 47 is obtained by the reaction of >-bromostyrene (46) with ethylene. The reaction has been applied to polymer synthesis[46]. One example is the reaction of 1,4-divinylbenzcne (48) with 9,10-dibromoanthracene to give the oligo(arylenevinylene)s 49[47]. 

The first series of soluble oligo(/ ara-phenylene)s OPVs 24 were generated by Kern and Wirth [48] and shortly after by Heitz and Ulrich [49]. They introduced alkyl substituents (methyls) in each repeat unit and synthesized oligomers 24 up to the hexamer. Various synthetic methods, like the copper-catalyzed Ullmann coupling, the copper-catalyzed condensation of lithium aryls, and the twofold addition of organomelallic species to cyclohexane-1,4-dione, have been thereby investigated. 

The branched oligo(arylene)s 37 and 40 can undeigo a further oxidative cyclization with copper(ll) chloride or triflate/aluminum trichloride leading to the formation of large, hitherto unknown polycyclic aromatic hydrocarbons PAHs 41 and 42. 

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