Poly Gilch polymerization

T. Ahn, S. Ko, J. Lee, and H. Shim, Novel cyclohexylsiyl — or phenylsiyl-substituted poly(p-phe-nylene vinylene)s via the halogen precursor route and Gilch polymerization, Macromolecules, 35 3495-3505, 2002. 

Satyanarayana and Elsenbaumer attempted the Gilch polymerization of monomer 191 to afford poly(bipyridinevinylene), 192, with [Ru(bpy)2]2+ complexed to each bpy in the conjugated backbone (Scheme 4.46).117 Unfortunately, the polymer obtained from this reaction was insoluble, and thus difficult to characterize. A large red shift in the optical spectrum was observed, and thermogravimetric analysis and IR spectroscopy also supported the structure assigned. The conductivity of the blue-black product was 4.5 X 10 6Scm 1. 

More recently, we have synthesized a new series of multifunctional EL polymers, poly[l,4- 2-(3,3 -diheptyl-3,4-propylenedioxythiophene-2-yl) phenylenevinylene] (PDOT-PPV), which is a series of fully conjugated PPV derivatives with a PDOT moiety as a pendant group. The polymerization of the monomers is outlined in Scheme 1.4. The homo- and copolymerization of monomers was performed by fhe Gilch polymerization... 

Fan, Y.-L, and K.-F. Lin. 2005. Dependence of the luminescent properties and chain length of poly[2-methoxy-5-(2 -ethylhexyloxy)]-l,4-phenylene vinylene on the formation of cis-vinylene bonds during Gilch polymerization. / Polym Set A 43 2520. 

The sulfonium precursor route may also be applied to alkoxy-substituted PPVs, but a dehydrohalogenation-condensation polymerization route, pioneered by Gilch, is favored 37]. The polymerization again proceeds via a quinomethide intermediate, but die syndicsis of the conjugated polymer requires only two steps and proceeds often in improved yields. The synthesis of the much-studied poly 2-methoxy-5-(2-ethylhexyloxy)-l,4-phenylene vinylene], MEH-PPV 15 is outlined in Scheme 1-5 33, 35]. The solubility of MEH-PPV is believed to be enhanced by the branched nature of its side-chain. 

The firsX(lO) and the second/"//J methods are known to be Wessling-Zimmerman method and Gilch-Wheelwright polymerization, respectively. The last reaction route is practically the same as that is utilized in the synthesis of poly(/ -xylylene) from /7-xylene via the CVD polymerization method. The first two methods have been widely used not only in the synthesis of PPV but also PPV derivatives. Since the methods produce soluble precursor polymers, the final polymer can be obtained in various shapes. 

However, we need to note that other chemical routes, rather than oxidation polymerization, can also be applied for conducting polymer synthesis. For example, polymers such as poly(pheny lene vinylene), poly(phenylene ethynylene), and their derivatives are usually synthesized using the Wittig reaction (Wittig and Schollkopf 1954), Heck reaction (Heck and Nolley 1972), and Gilch... 

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