Controlling π-Conjugated Polymer–Acceptor Interactions by Designing Polymers with a Mixture of π-Face Strapped and Nonstrapped Monomers

Abstract

Controlling π-conjugated polymer–acceptor complex interaction, including the interaction strength and location along the polymer backbone, is central to organic electronics and energy applications. Straps in the strapped π-conjugated polymers mask the π-face of the polymer backbone and hence are useful to control the interactions of the π-face of the polymer backbone with other polymer chains and small molecules compared to the conventional pendant solubilizing chains. Herein, we have synthesized a series of strapped π-conjugated copolymers containing a mixture of strapped and nonstrapped comonomers to control the polymer–acceptor interactions. Simulations confirmed that the acceptor is directed toward the nonstrapped repeat unit. More importantly, strapped copolymers overcome a major drawback of homopolymers and display higher photoinduced photoluminescence (PL) quenching, which is a measure of electron transfer from the polymer to acceptor, compared to that of both the strapped homopolymer and the conventional polymer with pendant solubilizing chains. We have also shown that this strategy applies not only to strapped polymers, but also to the conventional polymers with pendant solubilizing chains. The increase in PL quenching is attributed to the absence of a steric sheath around the comonomers and their random location along the polymer backbone, which enhances the probability of non-neighbor acceptor binding events along the polymer backbone. Thus, by mixing insulated and noninsulated monomers along the polymer backbone, the location of the acceptor along the polymer backbone, polymer–acceptor interaction strength, and the efficiency of photoinduced charge transfer are controllable compared to the homopolymers.

Advancing Evidence-Based Data Interpretation in UV–Vis and Fluorescence Analysis for Nanomaterials: An Analytical Chemistry Perspective

“…It is a common observation that addition of nanomaterials to fluorophore-containing solutions modifies (enhances or reduces) sample fluorescence. − However, the influence of absorption and scattering on the fluorescence signal has often been overlooked or insufficiently addressed. − The failure to correct the absorption inner filter effect (IFE) typically results in an underestimation of the sample’s true fluorescence intensity or an overestimation of nanoparticle-induced fluorescence quenching. Since the impact of scattering on sample fluorescence intensity is usually small, correcting only the sample IFE caused by sample absorption is usually adequate for most applications.…”

π-Face strapped monomers enable self-stabilized hyperbranched π-conjugated polymer particles

“…24 kDa) and two-dimensional π-conjugated oligomers, without the need for pendant solubilizing chains. 37–40 Furthermore, we successfully synthesized conjugated porous polymer networks using adamantyl strapped building blocks and irreversible P–C bond forming reactions. 41 The incorporation of adamantyl straps not only reduced interchain π–π interactions but also enhanced the residence time of the network in the reaction mixture, resulting in a swollen network that allowed monomers to diffuse and react, enabling control over the network size and crosslinking density.…”