Synthesis and characterization of ferrocene end-capped poly(ε-caprolactone)s by a combination of ring-opening polymerization and “click” chemistry techniques

• Published in: Reactive & functional polymers 2013-01, Vol.73 (1), p.244-253
• Main Authors: Eren, Oktay, Gorur, Mesut, Keskin, Bahadir, Yilmaz, Faruk
• Format: Article
• Language: English
• Subjects: Applied sciences; Click chemistry; Exact sciences and technology; Ferrocene; Organic polymers; Physicochemistry of polymers; Poly(ε-caprolactone); Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts; Ring-opening polymerization; Star polymers
• ISSN: 1381-5148
• DOI: 10.1016/j.reactfunctpolym.2012.10.009

Ferrocene (Fc) end-capped linear and star-shaped poly(ε-caprolactone)s (PCLs) with different numbers of arms were synthesized by a combination of ring-opening polymerization (ROP) and “click” chemistry techniques in a four-step reaction procedure. In the first step, the polymer backbones were prepared via ROP of the ε-caprolactone (ε-CL) monomer in bulk by employing the compounds with different numbers of hydroxyl groups as the multisite initiators and stannous octoate (Sn(Oct)2) as the coordination-insertion catalyst. The hydroxyl end-groups of the obtained PCLs were then converted into a bromides and azides consecutively. In the final step, the Fc moiety was attached to the termini of the PCLs using a Cu(I)-catalyzed 1,3-dipolar cycloaddition reaction between the azide end-groups of the PCLs and the acetylene group of ethynylferrocene under ambient conditions. In all cases, the FT-IR and 1H NMR spectra indicated a successful and quantitative transformation of the desired end-functional groups. The electrochemical properties of the Fc end-capped PCLs were also investigated via cyclic voltammetry (CV).