Kinetic studies of the photo-degradation of poly(arylene vinylenes)

Abstract

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractThe kinetics of the degradation of a homologous series of Poly phenylene vinylenes in which the phenylene units of the PPV structure are systematically substituted by naphthyl and anthyrl units is presented. Degradation is monitored according to the decay of the long wavelength absorption maximum upon illumination with UV radiation. Compared to Toluene solution, the photo-degradation is seen to be accelerated in Chloroform solution. All decays are fitted with first order kinetics. It is found that all substitutions improve the stability of the vinylene polymers against decay.In particular the highly electro-negative naphthyl group serves to drastically increase the stability due to electron depletion across the vinyl bond. The decay rate is shown to correlate well with the variation of the electronic properties of the backbone and with the reduction of vinylene bond strength as measured using Raman spectroscopy.

Dicyano-Substituted Poly(phenylenevinylene) (DiCN–PPV) and the Effect of Cyano Substitution on Photochemical Stability

“…Poly(alkoxyphenylenevinylene)s and poly(2,5-dialkoxycyanoterephthalylidene) have been investigated for light emission application. , Phenylenevinylene oligomers and polymers , are known to undergo fast photochemical oxidation by singlet oxygen . To systematically study the effect of LUMO energy on photostability of conjugated polymers without the complication by different side chains, we synthesized three polymers (Chart ) with different number of cyano groups on the exocyclic double bond in PPVs: poly(2,5-didecyloxy-1,4-phenylenevinylene) or C 10 O–PPV, poly(2,5-didecyloxycyanoterephthalylidene) or CN–PPV, and poly(2,5-didecyloxy-7,8-dicyano-1,4-phenylenevinylene), DiCN–PPV.…”