Date of Award
2004
Degree Type
Dissertation
First Advisor
Brett L. Lucht
Abstract
An investigation of the incorporation of phosphorus into conjugated polymers was conducted. Poly(aryl-P-alkylphosphine)s were prepared via palladium mediated coupling. The spectral and electrochemical properties of the polymers were investigated. Palladium catalyzed carbon-phosphorus bond formation was used for the preparation of poly(p-phenylene-P-alkylphoshpine)s via two routes. Low molecular weight polymers (1,000-3,000) were obtained by the condensation polymerization of 1,4-diiodobenzene with primary alkylphosphines. Higher molecular weight polymers (1,000-14,000) were obtained via polymerization of p-bromophenylalkylphosphines. The electronic properties of poly(aryl-P-alkylphosphine)s were investigated with UV-visible-NIR spectroscopy and cyclic voltammetry and support electronic delocalization along the polymer backbone through phosphorus. Phosphorus containing poly(N-arylaniline)s have been prepared via palladium catalyzed carbon-phosphorus bond formation. The molecular weight of the polymers is low and limited by solubility. The spectroscopic and electronic properties of the materials were investigated via UV Visible-NIR spectroscopy and cyclic voltammetry. PPPP-PANI copolymers containing p-phenylene diamine units in the polymer backbone have electronic and spectroscopic properties characteristic of aromatic substituted p-phenylene diamines. Copolymers containing -(-C6H 4-P-C6H4-P-C6H4-)- linkages between nitrogen centers show evidence for weak electronic delocalization along the polymer chain. The electrochemical and spectroscopic properties support strong electronic delocalization in copolymers containing -(-P-C 6H4-N-C6H4-)- repeat units. The presence of a single diphenylphosphine bridge between nitrogen centers provides an efficient mode of electronic delocalization between nitrogen centers. PPPP-PANI copolymers are a new type of π-conjugated polymer with low oxidation potentials and electronic delocalization through phosphorus along the polymer chain. The results were supported by the preparation and investigation of polymer model compounds. PPPP Oxide-PANI copolymers and related polymer model compounds were also prepared and investigated. The PPPP Oxide-PANI copolymers containing p-phenylene diamine units in the polymer backbone have electrochemical and spectroscopic properties similar to substituted p-phenylene diamines. Copolymers containing -(-C6H4-P-C6H 4-P-C6H4-)- linkages or -(-C6H 4-P-C6H4-)- linkages have similar electrochemical and spectroscopic properties to related triarylamines. The resemblance of PPPP Oxide-PANI copolymers to isolated p-phenylene diamines or triarylamines suggests electronic isolation of the amine fragments in the polymer. The conversion of phosphorus (III) phosphines to phosphorus (V) phosphine oxides inhibits electronic delocalization through phosphorus further supporting delocalization of the lone pair of electrons on phosphorus in PPPP-PANI copolymers.
Recommended Citation
Jin, Zhou, "Synthesis and characterization of novel phosphorus containing polymers" (2004). Open Access Dissertations. Paper 1978.
https://digitalcommons.uri.edu/oa_diss/1978
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