Abstract
Minor changes to side chains in conjugated polymers (CPs) can have pronounced effects on polymer properties by altering backbone planarity, solubility, and interaction with ions. Here, we report the photocontrolled synthesis of hydrophilic CPs from Grignard monomers and find that switching from alkyl to oligo(ethylene glycol) (OEG) side chains changes their photoreactivity. Specifically, installing hydrophilic side chains on the same monomer core yields higher molecular weight polymers and allows polymerization to proceed with lower-energy red light. Additionally, we discover a side chain decomposition pathway for N-OEG monomers, which are prevalent in CP research. Decomposition can be overcome by adding an extra methylene unit in the side chains without compromising polymer molecular weight or hydrophilicity. Importantly, this polymerization does not require transition metal catalysts and is a promising approach to the preparation of n-type conjugated block copolymers.
Original language | English (US) |
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Pages (from-to) | 503-509 |
Number of pages | 7 |
Journal | ACS Macro Letters |
Volume | 12 |
Issue number | 4 |
DOIs | |
State | Published - Apr 18 2023 |
Funding
This work was supported by funding from the Air Force Office of Scientific Research (FA9550-22-1-0421) and the American Association for the Advancement of Science through the Marion Milligan Mason Award. J.A.K. was supported by a Sloan Research Fellowship and a Dreyfus Teacher-Scholar Award. A.J.B. acknowledges support from a National Science Foundation Graduate Research Fellowship (Grant No. DGE-1842165). This work made use of NMR and MS instrumentation at the Integrated Molecular Structure Education and Research Center (IMSERC) at Northwestern, which has received support from the NSF (NSF CHE-9871268), Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205), the State of Illinois, and the International Institute for Nanotechnology. It also made use of the NUFAB facility of Northwestern University’s NUANCE Center, which has received support from the SHyNE Resource (NSF ECCS-2025633), the IIN, and Northwestern’s MRSEC program (NSF DMR-1720139); the MatCI Facility, supported by the MRSEC program of the National Science Foundation (DMR-1720139) at the Materials Research Center of Northwestern University; and the GIANTFab core facility, supported by the Institute for Sustainability and Energy at Northwestern and the Office of the Vice President for Research at Northwestern.
ASJC Scopus subject areas
- Materials Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Organic Chemistry