14609-51-9Relevant academic research and scientific papers
A Reversible Crystallinity-Preserving Phase Transition in Metal-Organic Frameworks: Discovery, Mechanistic Studies, and Potential Applications
Liu, Dahuan,Liu, Tian-Fu,Chen, Ying-Pin,Zou, Lanfang,Feng, Dawei,Wang, Kecheng,Zhang, Qiang,Yuan, Shuai,Zhong, Chongli,Zhou, Hong-Cai
, p. 7740 - 7746 (2015)
A quenching-triggered reversible single-crystal-to-single-crystal (SC-SC) phase transition was discovered in a metal-organic framework (MOF) PCN-526. During the phase transition, the one-dimensional channel of PCN-526 distorts from square to rectangular in shape while maintaining single crystallinity. Although SC-SC transformations have been frequently observed in MOFs, most reports have focused on describing the resulting structural alterations without shedding light on the mechanism for the transformation. Interestingly, modifying the occupancy or species of metal ions in the extra-framework sites, which provides mechanistic insight into the causes for the transformation, can forbid this phase transition. Moreover, as a host scaffold, PCN-526 presents a platform for modulation of the photoluminescence properties by encapsulation of luminescent guest molecules. Through judicious choice of these guest molecules, responsive luminescence caused by SC-SC transformations can be detected, introducing a new strategy for the design of novel luminescent MOF materials. (Figure Presented).
Synthesis and spectroscopy of a series of substituted N-confused tetraphenylporphyrins
Shaw, Janet L.,Garrison, Shana A.,Aleman, Elvin A.,Ziegler, Christopher J.,Modarelli, David A.
, p. 7423 - 7427 (2004)
A series of N-confused tetraphenylporphyrins (H2NCTPPs) with substituents on either the paraor the 3,5-positions of the meso phenyl rings were prepared using Lindsey conditions. Both electron-withdrawing and electron-donating groups were chosen in order to probe the effects of peripheral substitution on the properties of the macrocycles. The series includes 5,10,15,20-tetra-(4-R-phenyl) N-confused porphyrins (where R = bromo (1), iodo (2), cyano (3), methoxy (4), 2′,5′-dimethoxyphenyl (5), or ethynyl (6)) and 5,10,15,20-(3,5-di-ieri-butylphenyl) N-confused porphyrin (7). Absorption and steady-state fluorescence measurements were carried out, and quantum yields were measured for all compounds in both dichloromethane (CH 2Cl2) and dimethylacetamide (DMAc).
Synthesis, structure, and photophysical properties of some gadolinium(III) porphyrinate complexes
Zhu, Xun-Jin,Zhang, Tao,Zhao, Shunsheng,Wong, Wai-Kwok,Wong, Wai-Yeung
, p. 3314 - 3320 (2011)
A series of gadolinium(III) porphyrinate complexes was synthesized in moderate yield from the interaction of meso-substituted porphyrin free bases with Ln[N(SiMe3)2]3·x[LiCl(THF) 3], followed by the addition of a tripodal anion LOMe - - an effective encapsulating agent for lanthanide ions. These new complexes were fully characterized by X-ray crystallography, elemental analysis, mass spectrometry, and infrared spectroscopy. The electronic spectra show a near-infrared phosphorescence from the triplet state of the porphyrin rings and exhibit a very characteristic vibronic-structured emission. A series of gadolinium(III) porphyrinate complexes was synthesized and fully characterized by spectroscopic and X-ray crystallographic methods. The electronic spectra show near-infrared phosphorescence from the triplet state of the porphyrin rings and exhibit a very characteristic vibronic-structured emission. Copyright
Cobalt single-atoms anchored on porphyrinic triazine-based frameworks as bifunctional electrocatalysts for oxygen reduction and hydrogen evolution reactions
Yi, Jun-Dong,Xu, Rui,Chai, Guo-Liang,Zhang, Teng,Zang, Ketao,Nan, Bing,Lin, Hua,Liang, Yu-Lin,Lv, Jiangquan,Luo, Jun,Si, Rui,Huang, Yuan-Biao,Cao, Rong
, p. 1252 - 1259 (2019)
Designing and fabrication of highly active single-atom catalysts (SACs) with maximized atomic efficiency is highly desirable but still remains a great challenge. Herein, highly active and stable cobalt single-atoms with a Co-N4 moiety were uniformly anchored on a porous porphyrinic triazine-based framework (CoSAs/PTF) by a simple ionothermal method. Due to the abundant single-atom Co-N4 species, the hierarchical porous structure and the good conductivity, the resultant catalyst is highly active for the electrocatalytic oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). For the ORR, a more positive half-wave potential of 0.808 V (vs. RHE) was achieved, compared with commercial benchmark Pt/C (0.806 V). Furthermore, a small onset potential of 21 mV and a low Tafel slope of 50 mV per decade were obtained for the HER. The porphyrin-like structure was found to stabilize the CoSAs effectively, thus leading to long-term durability and a remarkable methanol-tolerant behavior. This bifunctional single-atom catalyst might be a promising candidate to replace Pt-based electrocatalysts in electrolysers and fuel cells.
A stable metal cluster-metalloporphyrin MOF with high capacity for cationic dye removal
Wang, Zheng,Zhang, Jian-Hua,Jiang, Ji-Jun,Wang, Hai-Ping,Wei, Zhang-Wen,Zhu, Xunjin,Pan, Mei,Su, Cheng-Yong
, p. 17698 - 17705 (2018)
A metalloporphyrin Cu5-cluster based MOF (metal-organic framework), [Cu4.5((H4TZPP)(TZPP)Cl2)(H2O)0.5]·CH3NH2CH3·7EtOH·8H2O (LIFM-WZ-3) was synthesized from the tetrapodal ligand 5,10,15,20-tetrakis[4-(2,3,4,5-tetrazolyl)phenyl]porphyrin (H6TZPP) and copper chloride. LIFM-WZ-3 exhibits a rare 2D + 3D → 3D interpenetration topology, of which the frl-type 3D MOF and a layered 2D HOF (hydrogen bond organic framework) are intertwined, leading to an anionic framework with 1D spindle-like channels. Powder X-ray diffraction analysis reveals that the framework is stable in acid, base and various organic solvent environments. LIFM-WZ-3 exhibits moderately high separation performances for CO2/CH4, CO2/N2, C3H6/CH4, C2H6/CH4, and C2H4/CH4 at room temperature. Specifically, the anionic framework in LIFM-WZ-3 containing dimethylamine cations can selectively adsorb cationic organic dyes from aqueous pollutants for recycle purpose. The high adsorption capacity for methylene-blue (MB+, 983 mg g-1) and crystal violet (CV+, 713.5 mg g-1) ranks the highest among those MOFs ever reported.
Highly Selective Tandem Electroreduction of CO2 to Ethylene over Atomically Isolated Nickel–Nitrogen Site/Copper Nanoparticle Catalysts
Cao, Rong,Hou, Ying,Huang, Yuan-Biao,Mao, Min-Jie,Meng, Dong-Li,Si, Duan-Hui,Zhang, Meng-Di
, p. 25485 - 25492 (2021)
Herein, an effective tandem catalysis strategy is developed to improve the selectivity of the CO2RR towards C2H4 by multiple distinct catalytic sites in local vicinity. An earth-abundant elements-based tandem electrocatalyst PTF(Ni)/Cu is constructed by uniformly dispersing Cu nanoparticles (NPs) on the porphyrinic triazine framework anchored with atomically isolated nickel–nitrogen sites (PTF(Ni)) for the enhanced CO2RR to produce C2H4. The Faradaic efficiency of C2H4 reaches 57.3 % at ?1.1 V versus the reversible hydrogen electrode (RHE), which is about 6 times higher than the non-tandem catalyst PTF/Cu, which produces CH4 as the major carbon product. The operando infrared spectroscopy and theoretic density functional theory (DFT) calculations reveal that the local high concentration of CO generated by PTF(Ni) sites can facilitate the C?C coupling to form C2H4 on the nearby Cu NP sites. The work offers an effective avenue to design electrocatalysts for the highly selective CO2RR to produce multicarbon products via a tandem route.
An ultrafast responsive NO2 gas sensor based on a hydrogen-bonded organic framework material
Wang, Yijie,Liu, Di,Yin, Jianbo,Shang, Yanxue,Du, Juan,Kang, Zixi,Wang, Rongming,Chen, Yanli,Sun, Daofeng,Jiang, Jianzhuang
, p. 703 - 706 (2020)
We report the development of a new type of organic semiconductor gas sensor based on a porphyrin-based hydrogen-bonded organic framework (HOF). Owing to the orderly porous structures, the decoration with rich amino sites and the n-type semiconductor nature, this HOF-based sensor exhibits selective NO2 sensing performance with ultra-fast response/recovery rates (17.6 s/15.4 s over 100 ppb) and a limit of detection lower than 40 ppb, together with high sensitivity, good reproducibility, and long-term stability at room temperature. This study demonstrates that HOF-based materials have potential application prospects in gas sensing, thereby offering a new way of thinking for the design and development of sensors.
Integration of metalloporphyrin into cationic covalent triazine frameworks for the synergistically enhanced chemical fixation of CO2
Cao, Rong,Chen, Jian-Xin,Huang, Yuan-Biao,Mao, Min-Jie,Wu, Qiu-Jin
, p. 8026 - 8033 (2020/12/28)
The design and preparation of porous catalysts with multiple catalytically active sites for synergistically catalytic conversion of CO2 still remains a challenge. Herein, cobalt porphyrin as a Lewis acidic active site was introduced in imidazolium-functionalized cationic covalent triazine frameworks (denoted as Co-PCCTFs) via copolymerization of cobalt 5,10,15,20-Tetrakis(4-cyanophenyl)porphyrin (Co-TPPCN) and 1,3-bis(4-cyanophenyl) imidazolium chloride ([BCIM]Cl). The obtained bifunctional Co-PCCTFs with positively charged imidazolium groups have high BET surface areas and show sufficient CO2 adsorption uptakes. The nucleophilic halide anions of the imidazolium parts and the cobalt porphyrin Lewis acid sites were positioned in close proximity so that the Co-PCCTFs could synergistically activate substrates and intermediates. Compared with ICTF-400 free of Co2+ that was obtained from [BCIM]Cl, Co-PCCTF5 exhibited enhanced activity for the cycloaddition of CO2 to epoxides to produce cyclic carbonates without a cocatalyst under mild conditions. Moreover, Co-PCCTF5 is sufficiently stable so that it could be reused more than 5 times without loss of catalytic activity. This work provides a new approach for the design and preparation of efficient multifunctional catalysts with multiple sites for synergistic catalysis.
Selective Solvent-Free and Additive-Free Oxidation of Primary Benzylic C–H Bonds with O2 Catalyzed by the Combination of Metalloporphyrin with N-Hydroxyphthalimide
Shen, Hai-Min,Qi, Bei,Hu, Meng-Yun,Liu, Lei,Ye, Hong-Liang,She, Yuan-Bin
, p. 3096 - 3111 (2020/04/29)
Abstract: A protocol for solvent-free and additive-free oxidation of primary benzylic C–H bonds with O2 was presented through adjusting the combination of metalloporphyrins and NHPI as binary catalysts to overcome the deficiencies encountered in current oxidation systems. The effects of reaction temperature, porphyrin structure, central metal, catalyst loading and O2 pressure were investigated systematically. For the optimized combination of T(2-OCH3)PPCo and NHPI, all the primary benzylic C–H bonds could be functionalized efficiently and selectively at 120 °C and 1.0?MPa O2 with aromatic acids as the primary products. The selectivity towards aromatic acids could reach up to 70–95% in the conversion of more than 30% for most of the substrates possessing primary benzylic C–H bonds in the metalloporphyrin loading of 0.012% (mol/mol). And the superior performance of T(2-OCH3)PPCo among the metalloporphyrins investigated was mainly attributed to its high efficiency in charge transfer and fewer positive charges around central metal Co (II) which favored the adduction of O2 to cobalt (II) forming the high-valence metal-oxo complex followed by the production of phthalimide N-oxyl radical (PINO) and the initiation of the catalytic oxidation cycle. This work would provide not only an efficient protocol in utilization of hydrocarbons containing primary benzylic C–H bonds, but also a significant reference in the construction of more efficient C–H bonds oxidation systems. Graphic Abstract: The solvent-free and additive-free oxidation of primary benzylic C–H bonds with O2 was presented through adjusting the combination of metalloporphyrins and NHPI as binary catalysts, and the highest selectivity towards aromatic acid reached up to 95.1% with the conversion of 88.5% in the optimized combination of T(2-OCH3)PPCo and NHPI.[Figure not available: see fulltext.].
Atomic Ni Anchored Covalent Triazine Framework as High Efficient Electrocatalyst for Carbon Dioxide Conversion
Lu, Chenbao,Yang, Jian,Wei, Shice,Bi, Shuai,Xia, Ying,Chen, Mingxi,Hou, Yang,Qiu, Ming,Yuan, Chris,Su, Yuezeng,Zhang, Fan,Liang, Haiwei,Zhuang, Xiaodong
, (2019/01/29)
Electrochemically driven carbon dioxide (CO2) conversion is an emerging research field due to the global warming and energy crisis. Carbon monoxide (CO) is one key product during electroreduction of CO2; however, this reduction proce
