Oligomer of well-defined structures

Electroactive Aniline Oligomers of Well-Defined Structures and Their Polymeric Derivatives... 

Detailed procedures for the synthesis ofa,o>-organofunctionally terminated siloxane oligomers with well defined structures have been given 50,66-67). Tables 6 and 7 provide the data on the synthesis and characteristics of aminopropyl and hydroxybutyl terminated polydimethylsiloxane oligomers prepared via anionic and cationic ringopening polymerization of octamethylcyclotetrasiloxane (D in the presence of appropriate disiloxanes, respectively. 

Determination of the unperturbed dimensions of the polymeric pro-cyanidins presents special challenges. Well-characterized samples of high molecular weight are not readily available, and the solubility characteristics of the high polymers are incompatible with the application of the classical techniques for the measurement of the dimensions of a macromolecule. An alternative route to the unperturbed dimensions exploits structural determinations in the solid state (8, 9), spectroscopic studies of well-characterized oligomers in dilute solution (iO, ii), molecular mechanics (MM2 software) (i2) calculations (i3, 14), and rotational isomeric state analysis (15-17) to provide a realistic description of the dimensions of the high polymers. A vital piece of information comes from the time-resolved fluorescence of the monomers and oligomers of well-defined covalent structure. The fluorescence measurements also show promise for the characterization of the com-... 

Synthesis and characterization of well-defined, a,w-terminated difunctional siloxane oligomers are discussed. Detailed procedures on the preparation of primary amine- and hydroxy-terminated oligomers are given. Control of the average molecular weight (Mn) and also the possible variations in the backbone structure and composition are explained. The effect of these variations on the physical, thermal and chemical properties of the resulting materials are discussed. Characterization of these oligomers by FT-IR, NMR and UV spectroscopy, potentiometric titration and DSC are summarized. 

Synthesis of Well Defined Copolymer Structures Starting from Ozonized Polymers Block Copolymers, Graft Copolymers, Telechelic Oligomers... 

The oligomers 39 have further been functionalized through introduction of redoxactive units such as viologen and ferrocene via an alkyl side chain 53 [156, 157]. The functionalization is thought to be of interest for the physical organic changes of electronic proj rties, but may also induce the formation of new supramolecular structures of well defined oligomers. The additional redox... 

The possible conformations of PFS chains in the solid state have attracted significant interest from several research groups and much work has also focused on the prototypical material, poly(ferrocenyldimethylsilane) 73 (R = R =Me). One contribution toward the understanding of conformations adopted by poly(ferrocenyldimethyl-silane) chains involved X-ray structural studies of well-defined oligomers. In particular, a model pentamer 97 was successfully characterized by single crystal X-ray diffraction. The pentamer molecules possess a trans-... 

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