- Three-dimensional porphyrin-based covalent organic frameworks with tetrahedral building blocks for single-site catalysis
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Two three-dimensional (3D) porphyrin covalent organic frameworks, PCOF-1 and PCOF-2, were synthesized via imine condensation of a planar porphyrin tetramine (TAPP or TABPP) and a rigid tetrahedral aldehyde based on the steric hindrance of 3,3′,5,5′-tetrakis(4-formylphenyl)bimesityl (TFBM). The structures of PCOF-1 and PCOF-2 were studied by FT-IR and 13C CP-MAS solid state NMR spectroscopy. Powder X-ray diffraction patterns revealed obvious crystallinity with two intense peaks at 3.28° and 3.75° for PCOF-1, and 2.63° and 2.98° for PCOF-2. Structural simulation confirmed their 3D rutile type (pts) topological structures with two different pore sizes. X-ray single crystal diffraction revealed a distorted tetrahedral structure for the building block TFBM with two dihedral angles of 119° and 107.8°, and a planar square structure for the model compound (MC) with an outspread angle of 176.5°. PCOF-1 and PCOF-2 exhibited Brunauer-Emmett-Teller (BET) surface areas of 316 and 234 m2 g-1, respectively. The morphologies of PCOF-1 and PCOF-2 were investigated by scanning electron microscopy and transmission electron microscopy methods. PCOF-1 and PCOF-2 showed a high thermal stability up to 420 °C without decomposition through thermogravimetric analysis (TGA), and high chemical stability with no obvious mass loss after three days of immersion in various solutions. Due to the large surface area and the appropriate pore size, PCOF-Fe exhibited excellent biocatalytic catalytic performance, while PCOF-Co exhibited good electrocatalytic activity towards oxygen evolution reactions. These results indicate that 3D porphyrin-based COFs constructed from the tetrahedral building block with steric hindrance are promising candidates for single-site catalysis.
- Liu, Yong,Yan, Xiaodong,Li, Tao,Zhang, Wen-Da,Fu, Qiu-Ting,Lu, Hui-Shu,Wang, Xuan,Gu, Zhi-Guo
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supporting information
p. 16907 - 16914
(2019/11/14)
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- Nondoped pure-blue OLEDs based on amorphous phenylenevinylene- functionalized twisted bimesitylenes
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The twisted bimesitylene scaffold hinders crystallization and imparts amorphous nature to the oligophenylenevinylenes (OPVs) generated by 2- and/or 4-fold functionalization. The resultant phenylenevinylenes 1?5 with unique molecular topology exhibit excellent thermal and solid-state luminescence properties. The amorphous nature permits their application as pure-blue emissive materials in OLEDs. Under nondoped conditions, the device performances observed surpass those for analogous and simple oligophenylenevinylenes known so far; for example, the device based on OPV 2 as an emitting material and structurally analogous Bim-DPAB as a hole-transporting material yields pure-blue electroluminescence with an external quantum efficiency of ca. 4.70% at 20 mA/cm2, which is higher than those reported for nondoped pure-blue OPV emitters.
- Moorthy, Jarugu Narasimha,Venkatakrishnan, Parthasarathy,Natarajan, Palani,Lin, Zhenghuan,Chow, Tahsin J.
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experimental part
p. 2599 - 2609
(2010/06/15)
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- Three-dimensional four-connecting organic scaffolds with a twist: Synthesis and self-assembly
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We have synthesized a novel class of four-connecting three-dimensional molecular scaffolds 2-5 based on biaryls for supramolecular self-assembly. The X-ray crystal structure analysis of 2 with ethanol reveals a novel O-H...O hydrogen-bonded helical self-a
- Moorthy, Jarugu Narasimha,Natarajan, Ramalingam,Venugopalan, Paloth
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p. 8568 - 8571
(2007/10/03)
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