Polyhedral Oligomeric Silsesquioxane Cage Integrated Soluble and Fluorescent Poly(3,4-Propylenedioxythiophene) Dye

Abstract

A new analog of poly (3,4-propylenedioxythiophene) conjugated polymers called PProDOT-POSS, where polyhedral oligomeric silsesquioxane (POSS) nanocage with alkyl substitutions was integrated on the bridge of 3,4-propylenedioxythiophene unit and its structure was confirmed by spectroscopic techniques, was reported. The polymers were synthesized via both chemical and electrochemical polymerization techniques. While chemical polymerization was carried out in the presence of anhydrous FeCl3 as an oxidant, a solution of 0.1 M tetrabutylammonium hexafluoride electrolyte dissolved in a mixture of dichloromethane and acetonitrile (1/3: v/v) was used as an electrolyte solution for electrochemical polymerization. Electro-optical properties of the corresponding polymers were characterized by using electroanalytical techniques such as cyclic voltammetry and square wave potentiometry, and spectrophotometric methods like ultraviolet-visible and fluorescent spectrophotometry. Corresponding polymers obtained both electrochemically and chemically are soluble completely in common organic solvents such as chloroform, toluene, dichloromethane, tetrahydrofuran, etc. Polymer samples both in film and solution forms can be doped/dedoped reversibly by using a chemical oxidant or an external potential. The optical bandgap of the neutral polymer film with a maximum absorption band at 555 nm was calculated as 1.95 eV. Polymers have fluorescent property and excited polymers represented a red/orange light with an emission band centered at 605 nm in toluene. Also, PProDOT-POSS polymers have electrochromic properties under external potentials and they have an optical contrast of 55% at 555 nm between their neutral and oxidized states. Upon oxidation, they showed high transparency and they can switch between redox states in a short time (switching time = similar to 1.0 s) as well as high coloration efficiency (502 cm(2)/C for 95% switching). It can be concluded that POSS based PProDOT polymers can be good candidates for optoelectronic and bioelectronics applications. Short Abstract for Paper Submission: A new analog of poly (3,4-propylenedioxythiophene) conjugated polymers called PProDOT-POSS, was reported with the integrated of alkyl-substituted polyhedral oligomeric silsesquioxane nanocage structure. The polymers were synthesized via both chemical and electrochemical polymerization techniques. Corresponding polymers obtained both electrochemically and chemically are soluble completely in common organic solvents such as chloroform, toluene, dichloromethane, tetrahydrofuran, etc. Polymer samples both in film and solution forms can be doped/dedoped reversibly by using a chemical oxidant or an external potential. The optical bandgap of the neutral polymer film with a maximum absorption band at 555 nm was calculated as 1.95 eV. Polymers have fluorescent property and excited polymers represented a red/orange light with an emission band centered at 605 nm in toluene.