N-confused porphyrin-based conjugated microporous polymers

Abstract

Metal porphyrins, which possess metal-N coordination centers, are important building blocks for construction of porous organic materials with catalytic performance. However, most of previous work focused on controlling metal elements...

Well‐defined N3C1‐anchored Single‐Metal‐Sites for Oxygen Reduction Reaction

“…[31] By comparison, the aforementioned peaks are shifted to a 0.9 eV lower binding energy in the Ni 2p spectrum of NCPor-Ni, suggesting that less electron transfer in NCPor-Ni occurs from Ni center to the porphyrin skeleton than does the electron transfer in Por-Ni because C atom has lower negativity than that of N atom. [32] Similar phenomena can be observed in the XPS spectra of the Mn, Co, and Pd sites (Figure S37), which is consistent with the results of XANES analysis (Figure S36). Notably, because the Ag(III) center in NCPor-Ag has higher valence than the Ag(II) center in Por-Ag, [18] the peaks assigned to Ag 3d 5/2 and Ag 3d 3/2 are located at an approximately 1.61 eV higher binding energy for NCPor-Ag than for Por-Ag.…”

“…On the basis of synchrotron UPS measurements, the HOMO energy of NCPor‐Co is calculated to be 6.23 eV, and this value for Por‐Co is 8.22 eV; this finding is in agreement with the calculated results (Figure S55). The synthesized NCPor‐Ms (M=Co, Ni, Cu, Pd, or Ag) exhibit narrower optical and electrochemical band gaps than those of corresponding Por‐Ms (Table S7; Figures S60–S64), which indicates the obvious advantage of NCPor skeletons and NCPor‐Ms for designing catalysts with narrow band gaps and high redox activity [32,39] …”

“…The Ni 2p XPS spectrum of Por‐Ni contains peaks at 871.8 and 854.5 eV, which correspond to Ni(II) 2p 1/2 and Ni(II) 2p 3/2 , respectively [31] . By comparison, the aforementioned peaks are shifted to a 0.9 eV lower binding energy in the Ni 2p spectrum of NCPor‐Ni, suggesting that less electron transfer in NCPor‐Ni occurs from Ni center to the porphyrin skeleton than does the electron transfer in Por‐Ni because C atom has lower negativity than that of N atom [32] . Similar phenomena can be observed in the XPS spectra of the Mn, Co, and Pd sites (Figure S37), which is consistent with the results of XANES analysis (Figure S36).…”

“…The synthesized NCPor-Ms (M = Co, Ni, Cu, Pd, or Ag) exhibit narrower optical and electrochemical band gaps than those of corresponding Por-Ms (Table S7; Figures S60-S64), which indicates the obvious advantage of NCPor skeletons and NCPor-Ms for designing catalysts with narrow band gaps and high redox activity. [32,39] The electrostatic potential surface and differential charge density of NCPor-Co and Por-Co were evaluated to analyze the charge distribution around the Co center. NCPor-Co exhibits obvious charge accumulation around the Co center because of the lower electronegativity of C atom compared with N atom (Figure S55 and Figure S65).…”

Conjugated Microporous Polymer Nanoparticles that Disperse in Water for Detection of Nitroaromatics

“…CMPs exhibit a high degree of flexibility in molecular design and photoelectric properties, allowing for the modification of conjugated backbones and nanopores through synthetic functionalization. The reactions for synthesizing CMPs include Yamamoto cross-coupling, Sonogashira-Hagihara cross-coupling, Suzuki-Miyaura cross-coupling, − Heck cross-coupling, and Schiff Base reaction . Due to their intrinsic microporosity and unique electronic structure, CMPs have found extensive applications in gas adsorption and separation, heterogeneous catalysis, energy storage, and especially fluorescence sensing. − However, their highly hydrophobic cross-linked structure hinders their dispersity in water, leading to challenges in achieving stable and efficient fluorescence sensing in the aqueous phase.…”