Enhancing Insulated Conjugated Polymer Fluorescence Quenching by Incorporating Dithia[3.3]paracyclophanes

Abstract

Insulated π-conjugated polymers exhibit enhanced chemical stability, photostability, fluorescence quantum yield, electroluminescence, solubility, and intrachain charge transport. However, insulated polymer fluorescence quenching by acceptor molecules is significantly hampered as the π-face is insulated. Photoinduced charge transfer is one of the key steps in amplified fluorescence quenching sensors and organic solar cells for charge generation. Inspired by the myelin sheath gaps in nerve cell axons, herein, we synthesized a series of insulated random copolymers of adamantanocyclophane with an increasing percentage of dithia[3.3]paracyclophane (PCP) from 5 to 30% to enhance the insulated polymer fluorescence quenching with acceptor molecules. As the percentage of the dithia[3.3]paracyclophane monomer increases, the copolymers showed an increase in absorption in the red region of the spectrum and also the copolymers' photoluminescence quantum yield reduced. The Stern−Volmer quenching constant of the 30% copolymer is ca. 4.5 times higher than that of the adamantanocyclophane homopolymer. A comparison with the control polymers indicated that the through-space-coupled interactions in PCP could be a plausible reason for the enhanced fluorescence quenching in copolymers in addition to the reduced steric hindrance by PCP. The developed copolymers combine the advantages of polymer insulation without significantly sacrificing the photoinduced charge transfer, which will help further their applicability as amplified fluorescence quenching sensors and in organic solar cells.

Coalescence Behavior of a CO2-Resistant Dispersed Particle Gel (SCDPG) in Supercritical CO2

“…The space steric hindrance effect was caused by the tendency of the hydrophilic groups of the polymer chains to extend into water. 44 When particles approached each other, the space steric hindrance effect generated an osmotic pressure that prevented the particles from coming closer. Furthermore, polymer chains with −COO − and −SO 3 − adsorbed on the surface of particles made the particles negatively charged.…”

Using molecular straps to engineer conjugated porous polymer growth, chemical doping, and conductivity

“…cycloaraliphanes) consist of an aryl face and a cycloalkyl face; the aryl group generates a p-conjugated polymer upon polymerization whereas the cycloalkyl group positioned either above or below the p-conjugation plane masks the p-surface and hinders interchain p-p interactions. 33 We have shown that the strapped monomers generate soluble linear 1D-p-conjugated polymers of higher molecular weight (M n : 23 kDa) 33,34 without the need for pendant solubilizing chains, and 2D-oligomers without pendant solubilizing chains. 35 This is mainly because the straps reduce interchain interactions, allowing the polymer chains to grow in solution.…”

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

“…Our group has been focused on developing molecular design strategies that take advantage of the straps in the strapped polymers in organic electronics and energy applications, especially for controlling the π-conjugated polymer–acceptor interactions. , Controlling the location of the dopant along the polymer backbone is considered one of the critical factors in determining charge generation, conductivity, and thermoelectric performance of π-conjugated polymers. − Typically, varying the structural parameters of the pendant chains and their location along the polymer backbone has been the widely used strategy to control the polymer-dopant (acceptor molecule in the case of a p -type strapped polymer) complex formation. − Recently, we have shown that straps can be used to control the location of the acceptor along a trimer backbone. The dopant molecule is directed toward the nonstrapped repeat units in trimers containing mixture of strapped and nonstrapped repeat units .…”

“…In addition to controlling the location of the acceptor along the polymer backbone, it is also desired to have an efficient electron transfer from the polymer to acceptor for electronics and energy applications. , To achieve this, a series of strapped copolymers containing 20 mole % randomly incorporated nonstrapped repeat units are synthesized (Scheme ). The impact of the structure of the nonstrapped monomers on the strapped copolymers interaction with the acceptor and photoinduced photoluminescence (PL) quenching, which is a measure of electron transfer from the polymer to the acceptor, ,− is studied. Simulations are performed on the trimers corresponding to each of the polymers to determine the location of the acceptor along the trimer and their interaction strength.…”