Reactive & Functional Polymers, Vol.73, No.1, 200-206, 2013
Synthesis of porphyrin-end-functionalized poly(p-phenylene) as a leaf-green-colored soluble semiconducting polymer: Control of pi-pi interactions for visible-light absorption
The synthesis of tetraphenylporphyrin (H2TPP)-end-functionalized poly(P-Phenylene) (H2TPP-PPP) as a leaf-green-colored soluble semiconducting polymer with a well-controlled and defined polymer chain structure was achieved for the first time. Chloromethyl-end-functionalized poly(1,3-cyclohexadiene) (CM-PCHD) was prepared by the living anionic polymerization of 1,3-cyclohexadiene and the post-polymerization reaction of poly(1,3-cyclohexadienyl)lithium and chloro(chloromethyl)dimethylsilane. H2TPP-end-functionalized PCHD (H2TPP-PCHD) was then prepared by the addition of 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin to CM-PCHD. The dehydrogenation of H2TPP-PCHD with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone was performed under ultrasonic irradiation, and H2TPP-PPP was obtained as a target polymer in almost quantitative yield. The -Si(CH3)(2)-CH2-O- bond in H2TPP-PPP effectively inhibited the coordination of the H2TPP end-group onto the PPP moiety, and the aggregation of H2TPP-PPP with the accumulation of the H2TPP end-group was formed. H2TPP-PPP exhibited a leaf-green color and had a very broad absorption band overlapping the visible-light region, similar to chlorophyll a. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords:Anionic polymerization;Porphyrins;End-functionalization;Visible-light absorption;Poly(p-phenylene)