Influence of the Building Unit on Covalent Organic Frameworks in Mediating Photo‐induced Energy‐Transfer Reversible Complexation‐Mediated Radical Polymerization (PET‐RCMP)

Abstract

Two imine-based covalent organic framework photocatalysts with different building units, TPB-DMTA-COF and TAT-DMTA-COF, for photo-induced energy transfer reversible complexation-mediated radical polymerization (PET-RCMP) were developed and investigated, producing ideal polymers with accurate molecular weight and moderate dispersity under visible light irradiation. The chain extension and spatiotemporal control experiments revealed the high chain-end fidelity of polymers and the compatibility of RCMP processes in both bulk and aqueous system. Moreover, density functional theory (DFT) calculations verified that heteroatom-doped TAT-DMTA-COF exhibits higher activities for weakening CÀ I bond energy barrier, which promotes PET-RCMP polymerization performance. This work demonstrates that rational adjustment of building block for constructing COF heterogeneous photocatalyst can enhance the catalytic performance of PET-RCMP, providing a design methodology for the development of polymeric organic photoelectric semiconductor catalysts to mediate RCMP.

Continuous synthesis of grafted polyesters through successive photocontrolled BIT-RDRP and ROP strategies in flow tube reactors

“…15 Recently, reversible complexation-mediated polymerization (RCMP) has been of particular interest to researchers for its simple components, metal-free feature, excellent compatibility, and broad monomer scope, [16][17][18] and has been an attractive and sustainable technique for polymer synthesis. [19][20][21][22] However, the alkyl iodine initiators used in RCMP are easy to decompose due to their thermal and photo instability, and they require high transportation and storage cost. To address this issue, Goto and Cheng independently reported a facile method of bromine-iodine transformation reversible-deactivation radical polymerization (BIT-RDRP) via in situ halogen exchange initiated by thermal treatment 23 or visible light, 24 avoiding the use of unstable alkyl iodide initiators.…”

A durable heterogeneous catalyst for photoinduced controlled radical polymerization under white LED light irradiation in an aqueous solution

“…46 Nevertheless, the polymerization of PEGMA in an aqueous solution using a heterogeneous catalyst is rarely reported. 47…”

“…46 Nevertheless, the polymerization of PEGMA in an aqueous solution using a heterogeneous catalyst is rarely reported. 47 In this paper, an ionic heterogeneous catalyst, TD-I, was synthesized in a facile manner. Then, PPEGMA was synthesized by RCMP using PEGMA as the monomer, 2-iodo-2methylpropionitrile (CP-I) as the initiator and TD-I as the catalyst.…”

Donor–Acceptor Covalent Organic Frameworks Films with Ultralow Band Gaps to Enhanced Third-Order Nonlinear Optical Properties

“…As determined from the transformed Kubelka−Munk function (see Figure 4b), 28,29 the optical band gaps (E g ) values of the PB−PA, PT−PA, PB−BD, and PT−BD were 1.51, 1.57, 1.70, and 1.77 eV, respectively, indicating that the narrowest band gap was observed when the strongest acceptor triphenyltriazine was bound to the strongest donor triphenylamine and easily absorb visible light. 30,31 Additionally, to describe the band structure, the work function (WF) values of the COF films were determined using Kelvin probe force microscopy (KPFM). After testing, the average contact potential difference (CPD) of Au is −3.574 mV, and the WF Au is called 5.20 eV (see Figure S16 in the Supporting Information).…”

“…From the UV–vis scattering reflection spectra (Figure a), it can be seen that the absorption band edges of PB–PA, PT–PA, PB–BD, and PT–BD are located at ∼652, 686, 590, and 620 nm, respectively, with good visible absorption and a wide absorption band. As determined from the transformed Kubelka–Munk function (see Figure b), , the optical band gaps ( E g ) values of the PB–PA, PT–PA, PB–BD, and PT–BD were 1.51, 1.57, 1.70, and 1.77 eV, respectively, indicating that the narrowest band gap was observed when the strongest acceptor triphenyltriazine was bound to the strongest donor triphenylamine and easily absorb visible light. , …”