Protocols for Efficient Postpolymerization Functionalization of Regioregular Polythiophenes

Abstract

Contents 1. General Experimental Methods 2. Experimental Procedures 2.1 Monomer Syntheses 2.2 Polymerization Procedures 2.3 Optimization of "Click-Chemistry" for Ethynyl-Terminated Poly(3-hexylthiophene) 2.4 Model Compound for End "Clicking" Reactions 2.5 Synthesis of Naphthalenediimides 2.6 Application of "Click-Chemistry" Conditions to Post-Polymerization Side-Chain Functionalization 3. NMR Spectra 4. Supplementary GPC Data 5. Supplementary UV-vis Data S2 General Experimental MethodsAll chemicals were purchased from commercial sources (Acros, Aldrich, Alfa Aesar, TCI, and Strem) and used without further purification, unless otherwise noted. THF was distilled from sodium-benzophenone ketyl. NBS was recrystallized from water. t-BuMgCl (nominally 1.0 M in THF) and ethynyl-MgBr (nominally 0.50 M in THF) were titrated against salicylaldehyde phenylhydrazone according to the method of Love (J. Org. Chem. 1999, 64(10), 3755). Common solvents were purchased from EMD (through VWR). Routine monitoring of reactions was carried out on glass-supported EMD silica gel 60 F 254 TLC plates. Flash chromatography was performed using silica gel from Sorbent Technologies (Standard Grade, 60 Å, 32-63 μm). All 1 H and 13 C{ 1 H} NMR spectra were recorded on a Bruker Avance400 spectrometer. 19 F NMR spectra were recorded on a Bruker DPX300 spectrometer. Chemical shifts and coupling constants (J) are reported in parts per million (δ) and Hertz, respectively. Deuterated solvents were obtained from Cambridge Isotope Laboratories, Inc. Chloroform-D (CDCl 3 ) contained 0.05% v/v tetramethylsilane (TMS) and this peak was set to 0.00 ppm on all proton spectra. In the case of 1,1,2,2-tetrachloroethane-D 2 (TCE), which did not contain TMS, the residual solvent peak was set to 6.00 ppm. Gel permeation chromatography (GPC) was done in the NSF-sponsored MaterialsResearch Science and Engineering Center on Polymers (MRSEC) at the University of Massachusetts Amherst. GPC analyses were performed on a Polymer Laboratories GPC50 integrated system with tetrahydrofuran (1.0 mL/min, 35 ºC) elution, 3 x Mixed C (300 x 7.5 mm) columns, and RI detection. Molecular weights were obtained based on polystyrene standards, with toluene as the flow rate marker, and may be overestimated by a factor of 1.5-2.0.UV-vis absorption spectra were measured with a Shimadzu UV 2600PC spectrometer in the laboratory of Prof. Paul M. Lahti (University of Massachusetts Amherst, Department of Chemistry). Stock solutions of polymers (c = 1 mg/10 mL) were prepared in spectrophotometric grade chloroform (Fisher, Optima) and diluted 10x (c = 1 mg/100 mL) in order to attain absorbances < 1.0. Films for UV-vis experiments were prepared by drop-casting solutions of polymer (c = 1 mg/mL) onto glass cover slips (Fisher Cat. No. 12-548-B) and allowing the solvent to freely evaporate.

Kumada chain-growth polycondensation as a universal method for synthesis of well-defined conjugated polymers

“…were also synthesized [45][46][47][48][49][50]. Although no detailed study on the polymerization mechanism was reported, the polymerization may also follow chain-growth mechanism.…”

“…Although no detailed study on the polymerization mechanism was reported, the polymerization may also follow chain-growth mechanism. The polymerization for PT5 has to be carried out at 70 °C [46]. At low temperature such as room temperature used in the preparation of P3HT, very little of the targeted polymer was obtained.…”

“…In the melt phase, it could assemble into a microphase-separated lamellar structure with two crystalline domains. Polythiophene-based FCBPs with one block carrying functional groups, such as P3RT-b-P3ORT and P3HT-b-P3AET, were prepared for studying supramolecular chirality or postfunctionalization [46,67]. FCBP with naphthalimide moieties in side chains was prepared from P3HT-b-P3AET via "click" chemistry method [46].…”

Termination reaction of living poly(3-hexylthiophene) using thiophene Grignard reagents: Substituent effect on the functionalization

“…2,3 In the early part of this century, a significant breakthrough came from the work of McCullough et al and Yokozawa et al They independently developed the well-defined Kumada catalyst transfer polymerization (KCTP) to prepare P3HT with the high regioregularity, predictable molecular weight, and controlled terminal structure. [4][5][6][7] The discovery of this innovative methodology opens the door for the preparation of block copolymers, 8,9 alternating copolymers, 10 polymer brushes 11 to name a few. In the KCTP, 2,5-dibromo-3-hexylthiophene or 2-bromo-3-hexyl-5-iodothiophene is firstly subjected to the halogen-metal exchange reaction with RMgCl to generate 2-bromo-5-chloromagnesio-3-hexylthiophene in the moderate to high selectivity.…”

Synthesis of Novel π-Conjugated Rod-Rod-Rod Triblock Copolymers Containing Poly(3-hexylthiophene) and Polyacetylene Segments by Combination of Quasi-Living GRIM and Living Anionic Polymerization

“…Although there are many examples of rod-coil P3HT-based BCPs , all conjugated rod-rod P3HT-based BCPs [41][42][43][44][45][46][47][48][49][50][51][52] are still less focused on and limited only to diblock copolythiophene derivatives, regardless of the expectation of high performance as semiconductors, due to the absence of insulating coil segments. Two exceptional examples of well-defined all conjugated rod-rod BCPs, P3HT-b-poly(2,6-dialkoxyphenylene) [53] and P3HT-b-poly(9,9-dioctylfluorene) [54], were very recently synthesized, comprised of different conjugated backbone structures, based on sequential quasi-living GRIM polymerization.…”