Polymerization Mechanism of 1-[(Butylsulfi(o)nyl)methyl]-4-(halomethyl)benzene:  The Effect of Polarizer and Leaving Group

Abstract

A synthesis route to soluble high molecular weight poly(p-xylylene) derivatives has been investigated. This method provides a versatile route to poly(phenylenevinylene) (PPV) from a precursor polymer that is amenable to the conventional nonaqueous processing techniques. To investigate the mechanism in the solvent mixture, monomethylformamide (MMF)/CH 2Cl2 (60/40), the influence of the leaving group and polarizer of the monomer was studied. The evaluation of the molecular weight of the polymer, the polymer yield, and the residual low molecular weight fraction indicates that only the kind of polarizer has an effect on the reaction in contrast with the leaving group, having no observable effect.

The Gilch Synthesis of Poly(p‐phenylene vinylenes): Mechanistic Knowledge in the Service of Advanced Materials

“…[107,108] Dimerization of a small number of species IX, which leads to dimeric diradicals XI, was assumed to be the dominant initiation event. [106] In 1999, moreover, Vanderzande and co-workers showed that high-molecular-weight polymers form in the polar-protic solvent N-methylformamide whereas a bimodal molar mass distribution appears in the polar-aprotic solvent N-methylpyrrolidone (NMP). [105] This implies that anionic and radical chain growth occur in parallel in NMP, an interpretation that was further supported by experiments where either water or TEMPO was added to the entries in NMP: in the case of water, the low-molecularweight part of the bimodal distribution curve was missing, whereas it was the high-molecular-weight part with TEMPO.…”

Facile Synthesis of Well-Defined MDMO-PPV Containing (Tri)Block—Copolymers via Controlled Radical Polymerization and CuAAC Conjugation

“…of CBr4 in the sulfinyl route. Moreover, even though general uncertainties exist for precursor polymerizations with respect to mechanism and individual rate coefficients, the sulfinyl route is amongst the best studied precursor routes [16][17][18][19][20]. Further systematic kinetic investigation of this reaction type is thus highly useful and thus the reason why-in spite of the better results for the DTC route-further investigation still focuses on the sulfinyl route.…”

“…In order to target such applications, controlled polymerization methodologies need to be developed to reach a precision polymer design of these materials and to make them available for combination with other types of materials. Significant research has been performed towards the synthesis of PPVs, resulting in the indirect or so-called "precursor" route as the most established and reliable synthetic pathway [10][11][12][13][14][15][16][17][18][19][20][21]. The general polymerization mechanism proceeds via a self-initiating p-quinodimethane moiety, which is formed upon the 1,6-base elimination of a premonomer that then spontaneously polymerizes to form a precursor polymer [16,22,23].…”

“…In a second step, elimination of the side group takes place, resulting in the desired conjugated polymer [15,23]. Over the last decades, different precursor routes were developed, for which the most important ones are the Gilch [11], Wessling [10,12,13], Xanthate [14,15], Sulfinyl [16][17][18][19][20] and Dithiocarbamate (DTC) route [28,29]. The sulfinyl route differs from the other routes since it is the only route in which an unsymmetrical premonomer is used and in which active monomer formation and prepolymer elimination can be fully separated from each other.…”

“…Consequently, a better control over the polymerization is gained. Low defect levels in the polymer chain are obtained, enabling only head-tail couplings of the polymer chains, leading to soluble and high molecular weight polymers [16][17][18][19][20][21]. Depending on the base and the type of solvent used, sulfinyl polymerizations can either follow a controlled anionic pathway (lithium hexamethyldisilazide (LHMDS) as base and THF as solvent) [26,30] or a radical pathway (sodium tert-butoxide (NatBuO) as base and s-BuOH as solvent) [31].…”