D. Vanderzande

PPV Polymerization via the Gilch Route: Diradical Character of Monomers

J.D. Nikolic, S. Wouters, J. Romanova, A. Shimizu, B. Champagne, T. Junkers, D. Vanderzande, D. Van Neck, M. Waroquier, V. Van Speybroeck, S. Catak
Chemistry - A European Journal
21, 19176-19185


Despite various studies on the polymerization of poly(p-phenylene vinylene) (PPV) through different precursor routes, detailed mechanistic knowledge on the individual reaction steps and intermediates is still incomplete. The present study aims to gain more insight into the radical polymerization of PPV through the Gilch route. The initial steps of the polymerization involve the formation of a p-quinodimethane intermediate, which spontaneously self-initiates through a dimerization process leading to the formation of diradical species; chain propagation ensues on both sides of the diradical or chain termination occurs by the formation of side products, such as [2.2]paracyclophanes. Furthermore, different p-quinodimethane systems were assessed with respect to the size of their aromatic core as well as the presence of heteroatoms in/on the conjugated system. The nature of the aromatic core and the specific substituents alter the electronic structure of the p-quinodimethane monomers, affecting the mechanism of polymerization. The diradical character of the monomers has been investigated with several advanced methodologies, such as spin-projected UHF, CASSCF, CASPT2, and DMRG calculations. It was shown that larger aromatic cores led to a higher diradical character in the monomers, which in turn is proposed to cause rapid initiation.

Kinetic and Mechanistic Study on p-Quinodimethane Formation in the Sulfinyl Precursor Route for the Polymerization of Poly(p-phenylenevinylene) (PPV)

L. Hermosilla, S. Catak, V. Van Speybroeck, M. Waroquier, J. Vandenbergh, F. Motmans, P. Adriaensens, L. Lutsen, T. Cleij, D. Vanderzande
43 (18), 7424–7433


The kinetics of p-quinodimethane formation in the sulfinyl precursor route for the poly(p-phenylenevinylene) (PPV) polymerization was studied using stop-flow UV−vis spectroscopy and theoretical first principle calculations. Different sulfinyl monomers were studied by means of quantitative kinetic experiments regarding the p-quinodimethane formation in 2-butanol. The influence of the solvent, the nature of the aromatic moiety, and the substituents on the phenyl core was analyzed by means of qualitative experiments. Quantitative measurements, using pseudo-first-order reaction conditions, were performed in order to assess the effect of the polarizer and the leaving group on the reaction rates. To obtain additional fundamental insight into the pathway leading to p-quinodimethane formation, density functional theory calculations were performed and subsequent reaction rate coefficients were determined from a theoretical point of view, enabling a profound comparison with experiment. From all these data, an E2 mechanism is proposed for the p-quinodimethane formation in the sulfinyl precursor route.

Computational insight into the polymerization of conjugated electroluminescent polymer PPV: Diradical character of monomers and dimers


Conference / event / venue 

250th ACS National Meeting & Exposition - Division of Catalysis Science and Technology (CATL)
Boston, MA, USA
Sunday, 16 August, 2015 to Thursday, 20 August, 2015

DFT insight into the polymerization mechanism of conjugated electroluminescent polymer PPV


Conference / event / venue 

Structure-property relationships of molecular precursors to organic electronics
Lausanne, Switzerland
Tuesday, 22 October, 2013 to Friday, 25 October, 2013

Kinetic and Mechanistic Study on the radical PPV polymerization via the Gilch route including diradical character of different monomers and dimers


Conference / event / venue 

Annual IAP Meeting
Ghent, Belgium
Wednesday, 18 September, 2013
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