14416-24-1Relevant articles and documents
Screening Libraries of Semifluorinated Arylene Bisimides to Discover and Predict Thermodynamically Controlled Helical Crystallization
Ho, Ming-Shou,Partridge, Benjamin E.,Sun, Hao-Jan,Sahoo, Dipankar,Leowanawat, Pawaret,Peterca, Mihai,Graf, Robert,Spiess, Hans W.,Zeng, Xiangbing,Ungar, Goran,Heiney, Paul A.,Hsu, Chain-Shu,Percec, Virgil
, p. 723 - 739 (2016)
Synthesis, structural, and retrostructural analysis of a library containing 16 self-assembling perylene (PBI), 1,6,7,12-tetrachloroperylene (Cl4PBI), naphthalene (NBI), and pyromellitic (PMBI) bisimides functionalized with environmentally friendly AB3 chiral racemic semifluorinated minidendrons at their imide groups via m = 0, 1, 2, and 3 methylene units is reported. These semifluorinated compounds melt at lower temperatures than homologous hydrogenated compounds, permitting screening of all their thermotropic phases via structural analysis to discover thermodynamically controlled helical crystallization from propeller-like, cogwheel, and tilted molecules as well as lamellar-like structures. Thermodynamically controlled helical crystallization was discovered for propeller-like PBI, Cl4PBI and NBI with m = 0. Unexpectedly, assemblies of twisted Cl4PBIs exhibit higher order than those of planar PBIs. PBI with m = 1, 2, and 3 form a thermodynamically controlled columnar hexagonal 2D lattice of tilted helical columns with intracolumnar order. PBI and Cl4PBI with m = 1 crystallize via a recently discovered helical cogwheel mechanism, while NBI and PMBI with m = 1 form tilted helical columns. PBI, NBI and PMBI with m = 2 generate lamellar-like structures. 3D and 2D assemblies of PBI with m = 1, 2, and 3, NBI with m = 1 and PMBI with m = 2 exhibit 3.4 ? π-π stacking. The library approach applied here and in previous work enabled the discovery of six assemblies which self-organize via thermodynamic control into 3D and 2D periodic arrays, and provides molecular principles to predict the supramolecular structure of electronically active components.
Self-assembly of semifluorinated Janus-dendritic benzamides into bilayered pyramidal columns
Percec, Virgil,Imam, Mohammad R.,Bera, Tushar K.,Balagurusamy, Venkatachalapathy S. K.,Peterca, Mihai,Heiney, Paul A.
, p. 4739 - 4745 (2007/10/03)
(Figure Presented) Two faces: Semifluorinated Janus-dendritic benzamides self-assemble into supramolecular bilayered pyramidal columns with diameters over twofold greater than those of columns generated from twin-dendritic benzamides (see model). The Janu
Complete destruction of p-Nitrophenol in aqueous medium by electro-fenton method
Oturan,Peiroten,Chartrin,Acher
, p. 3474 - 3479 (2007/10/03)
An indirect electrochemical method, which is very efficient for the degradation of organic pollutants in water, is described. The method, named electro-Fenton, is based on electrocatalytical generation of Fenton's reagent to produce hydroxyl radicals, which are very active toward organic compounds. An industrial pollutant, p-nitrophenol (PNP), was chosen for this study and was eventually mineralized. The major intermediary degradation products such as hydroquinone, benzoquinone, 4-nitrocatechol, 1,2,4-trihydroxybenzene and 3,4,5-trihydroxynitrobenzene were unequivocally identified by HPLC and GC-MS methods. The rate constants of the hydroxylation reactions were determined. The mineralization of the initial pollutant and the intermediates formed during electro-Fenton treatment was followed by total organic carbon (TOC) analyses. Dependence of mineralization on the amount of electrical energy consumed is shown by the relative decrease ofTOC values. A mineralization reaction mechanism is proposed. An indirect electrochemical method, which is very efficient for the degradation of organic pollutants in water, is described. The method, named electro-Fenton, is based on electrocatalytical generation of Fenton's reagent to produce hydroxyl radicals, which are very active toward organic compounds. An industrial pollutant, p-nitrophenol (PNP), was chosen for this study and was eventually mineralized. The major intermediary degradation products such as hydroquinone, benzoquinone, 4-nitrocatechol, 1,2,4-trihydroxybenzene and 3,4,5-trihydroxynitrobenzene were unequivocally identified by HPLC and GC-MS methods. The rate constants of the hydroxylation reactions were determined. The mineralization of the initial pollutant and the intermediates formed during electro-Fenton treatment was followed by total organic carbon (TOC) analyses. Dependence of mineralization on the amount of electrical energy consumed is shown by the relative decrease of TOC values. A mineralization reaction mechanism is proposed. The destruction of p-nitrophenol by the electro-Fenton method was examined. The method is based on the oxidation of the substrate by hydroxyl radicals generated in situ in an electrochemically induced Fenton reaction. The progress of all reactions and product distribution were monitored by high-performance liquid chromatography and gas chromatography-mass spectrometry. Results showed that p-nitrophenol disappeared, as did the degradation products after reaching a maximum concentration. The rapid degradation of p-nitrophenol was accompanied by the appearance of aromatic intermediates, such as p-nitrocatechol and hydroquinone. The subsequent decrease in p-nitrocatechol was accompanied by an increase in 1,2,4-trihydroxybenzene, while the decrease in hydroquinone was accompanied by the production of benzoquinone. The mineralization mechanism is described. The variation in TOC values taken at different times during treatment showed their dependence on the charge passed or electrical energy consumed.
