Control of reactivity of constitutional isomers of pentafluorophenyl ethynylbenzoates for the synthesis of functional poly(phenylacetylenes)

Electrochromic Poly(acetylene)s with Switchable Visible/Near‐IR Absorption Characteristics

“…A copper‐mediated coupling reaction effectively converted 1‐bromoferrocene to 1‐azidoferrocene, which was subsequently reduced to air‐sensitive 1‐aminoferrocene in 45% yield . In parallel, poly(pentafluorophenyl 2‐ethynylbenzoate) ( P1 ) was synthesized according to a recently published procedure and determined by gel permeation chromatography to display a number‐average molecular weight () of 15 000 g mol −1 and a polydispersity index of 1.44. Treatment of P1 with 0.5 equivalents of 1‐aminoferrocene under an inert‐atmosphere afforded P1·Fc as a purple solid (Scheme ).…”

“…Although the limited solubility and poor chemical stability of polyacetylene (PA) restricts the utility of this material, substituted PAs have found broad applications in sensing, as platforms for new macromolecular architectures and in gas permeable membranes . We have previously reported that poly(phenylacetylene)s (PPA)‐bearing pendant‐activated ester groups exhibit good chemical stability and solubility, and are amenable to the postpolymerization modification with a variety of amines . Moreover, the electronic properties of the PPAs, as measured primarily through their absorption profiles, can be conveniently and linearly tuned through modification .…”

“…We have previously reported that poly(phenylacetylene)s (PPA)‐bearing pendant‐activated ester groups exhibit good chemical stability and solubility, and are amenable to the postpolymerization modification with a variety of amines . Moreover, the electronic properties of the PPAs, as measured primarily through their absorption profiles, can be conveniently and linearly tuned through modification . Building on these results, we envisioned a new class of electrochromic materials through the incorporation of Fc groups.…”

“…Although Fc‐containing PAs may be found in the literature, most of these materials were reported as oligomers or low‐molecular‐weight polymers with the exception of a soluble poly(ethynylferrocene) (50 repeat units) prepared using the Schrock catalyst . As previously described, the use of activated ester poly(acetylene) precursors effectively overcomes the molecular weight limitation and allows for precise control over the degree of functionalization. Furthermore, while there is precedent for incorporating redox‐active functional groups, including Fc, into a conjugated polymer via the postpolymerization amidation of an activated ester‐functionalized polypyrrole, electronic communication between the two aforementioned components was restricted by the saturated linker employed.…”

Synthesis of 4-Arm Polystyrene Star Polymers by Sequential Reactions

“…Upon this reaction, the activated PFP-ester gets substituted quantitatively by an amine yielding the respective amide. Full conversion can be achieved under mild conditions with a multitude of different primary amines (5,(10)(11)(12). The reaction can be tracked by NMR spectroscopy.…”