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1.
Prof. Hui-Min Wen Chenyi Yu Miaoyu Liu Chenyan Lin Beiyu Zhao Dr. Hui Wu Dr. Wei Zhou Prof. Banglin Chen Prof. Jun Hu 《Angewandte Chemie (International ed. in English)》2023,62(44):e202309108
One-step separation of C2H4 from ternary C2 mixtures by physisorbents remains a challenge to combine excellent separation performance with high stability, low cost, and easy scalability for industrial applications. Herein, we report a strategy of constructing negative electrostatic pore environments in a stable, low-cost, and easily scaled-up aluminum MOF (MOF-303) for efficient one-step C2H2/C2H6/C2H4 separation. This material exhibits not only record high C2H2 and C2H6 uptakes, but also top-tier C2H2/C2H4 and C2H6/C2H4 selectivities at ambient conditions. Theoretical calculations combined with in situ infrared spectroscopy indicate that multiple N/O sites on pore channels can build a negative electro-environment to provide stronger interactions with C2H2 and C2H6 over C2H4. Breakthrough experiments confirm its exceptional separation performance for ternary mixtures, affording one of the highest C2H4 productivity of 1.35 mmol g−1. This material is highly stable and can be easily synthesized at kilogram-scale from cheap raw materials using a water-based green synthesis. The benchmark combination of excellent separation properties with high stability and low cost in scalable MOF-303 has unlocked its great potential in this challenging industrial separation. 相似文献
2.
Dr. Gang-Ding Wang Dr. Yong-Zhi Li Prof. Rajamani Krishna Prof. Wen-Yan Zhang Prof. Lei Hou Prof. Yao-Yu Wang Prof. Zhonghua Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(15):e202319978
Ethylene (C2H4) purification and propylene (C3H6) recovery are highly relevant in polymer synthesis, yet developing physisorbents for these industrial separation faces the challenges of merging easy scalability, economic feasibility, high moisture stability with great separation efficiency. Herein, we reported a robust and scalable MOF (MAC-4) for simultaneous recovery of C3H6 and C2H4. Through creating nonpolar pores decorated by accessible N/O sites, MAC-4 displays top-tier uptakes and selectivities for C2H6 and C3H6 over C2H4 at ambient conditions. Molecular modelling combined with infrared spectroscopy revealed that C2H6 and C3H6 molecules were trapped in the framework with stronger contacts relative to C2H4. Breakthrough experiments demonstrated exceptional separation performance for binary C2H6/C2H4 and C3H6/C2H4 as well as ternary C3H6/C2H6/C2H4 mixtures, simultaneously affording record productivities of 27.4 and 36.2 L kg−1 for high-purity C2H4 (≥99.9 %) and C3H6 (≥99.5 %). MAC-4 was facilely prepared at deckgram-scale under reflux condition within 3 hours, making it as a smart MOF to address challenging gas separations. 相似文献
3.
Jos�� M. L��pez-de-Luzuriaga Miguel Monge M. Elena Olmos Mar��a Rodr��guez-Castillo Antonio Laguna Fernando Mendizabal 《Theoretical chemistry accounts》2011,129(3-5):593-602
The interaction of bisperhalophenyl aurates [AuR2]? (R?=?C6F5, C6F3Cl2, and C6Cl5) with the closed-shell Ag+, Cu+, and Tl+ ions has been studied theoretically and compared with the experimentally known X-ray diffraction crystal structures. Initially, the aurates have been fully optimized at MP2 level of theory in a D 2h symmetry. The analysis of the basicity of the three aurates [AuR2]? (R?=?C6F5, C6F3Cl2 and C6Cl5) against Ag+ ions in a C 2v symmetry has been calculated in point-by-point bsse-corrected interaction energy analysis at HF and MP2 levels of theory. Taking into account the experimental observation of additional interactions between the heterometals and C ipso atoms at the perhalophenyl rings or halogen atoms at the ortho position of the perhalophenyl rings, dinuclear models of the type [AuR2]?···Ag+ (R?=?C6Cl5, and C6F5); [AuR2]?···Cu+ (R?=?C6F5, and C6Cl5) and [AuR2]?···Tl+ (R?=?C6F5, and C6Cl5) with a C 2v , C 2 , and C s symmetries have been optimized at DFT-B3LYP level. The interaction energies have been computed through bsse-corrected single point HF and MP2 calculations. The energy stabilization provided and the heterometal preference have been analyzed and compared with the experimental results. 相似文献
4.
Inorganic-organic hybrid membranes containing silica as the structure matrix, poly(N-vinylpyrrolidone) (PVP) as the organic mediating agent and silver ions as olefinic carriers were prepared using sol–gel method and dip-coating process. The structure and permeances of the membranes for N2, He, C2H4, C2H6 at different temperatures indicated that defect-free membranes were obtained and the transportation of the C2H4 through the membranes followed the dissolution and diffusion mechanism. Ideal separation factors of C2H4/C2H6 through the membranes were evaluated at the temperature of 298, 373 and 423 K respectively using mixture gas of 50% C2H4-50% C2H6. The results showed that the ideal separation factors of C2H4/C2H6 through the membranes were obviously greater than the ratio of PC2H4/PC2H6 obtained from the single gas measurement due to the hindering effect by the adsorbed C2H4. The ideal separation factors of C2H4/C2H6 increased with temperature and reached 10 at 423 K, which suggested that C2H4 and C2H6 could be separated at lower humidity compared to the reported organic polymer/silver salt membranes in which humidified gases and higher silver loading were usually used. The transport of C2H4 in the inorganic-organic hybrid membrane was proposed to follow the hopping mechanism, that is, olefins moved across the fixed silver sites. 相似文献
5.
Treatment of tetrakis(tetramethylethylenedioxyboryl)methane, (Me4C2 - O2B)4C, in THF with butyllithium at ?78° generates the tris(tetramethylethylenedioxyboryl)methide ion, (Me4C2O2B)3C?, which reacts with chlorotrimethylsilane at ?78° to form trichlorosilyltris(tetramethylethylenedioxyboryl)-methane, (Me4C2O2B)3CSiMe3. The yield was low, but other attempts to form silyltriborylmethanes have failed altogether. The ion (Me4C2O2B)3C? reacts with tetraphenylcyclopentadienone at ?78° to form the expected fulvene, 1,1-bis-(tetramethylethylenedioxyboryl)-2,3,4,5-tetraphenylfulvene. The red color of the tetraphenylcyclopentadienone is converted immediately to the brown of the fulvene product, indicating that the β-elimination of boron and oxygen occurs rapidly under basic conditions at ?78°. 相似文献
6.
Xue Jiang Dr. Tony Pham Jian-Wei Cao Dr. Katherine A. Forrest Dr. Hui Wang Dr. Juan Chen Prof. Dr. Qiu-Yu Zhang Prof. Dr. Kai-Jie Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(36):9446-9453
Rigid molecular sieving materials are the ideal candidates for gas separation (e. g., C2H2/C2H4) due to their ultrahigh adsorption selectivity and the absence of gas co-adsorption. However, the absolute molecular sieving effect for C2H2/C2H4 separation has rarely been realized because of their similar physicochemical properties. Herein, we demonstrate the absolute molecular sieving of C2H2 from C2H4 by a rigid ultra-microporous metal-organic framework ( F−PYMO−Cu ) with 1D regular channels (pore size of ca. 3.4 Å). F−PYMO−Cu exhibited moderate acetylene uptake (35.5 cm3/cm3), but very low ethylene uptake (0.55 cm3/cm3) at 298 K and 1 bar, yielding the second highest C2H2/C2H4 uptake ratio of 63.6 up to now. One-step C2H4 production from a binary mixture of C2H2/C2H4 and a ternary mixture of C2H2/CO2/C2H4 at 298 K was achieved and verified by dynamic breakthrough experiments. Coupled with excellent thermal and water stability, F−PYMO−Cu could be a promising candidate for industrial C2 separation tasks. 相似文献
7.
Xue Jiang Prof. Dr. Yu Wang Jian-Wei Cao Zi-Ming Ye Dr. Tao Zhang De-Xuan Liu Kai-Lei Li Rong Yang Prof. Dr. Teng Wang Prof. Dr. Qiu-Yu Zhang Prof. Dr. Kai-Jie Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(50):12753-12757
Low-concentration ethane capture is crucial for environmental protection and natural gas purification. The ideal physisorbent with strong C2H6 interaction and large C2H6 uptake at low-concentration level has rarely been reported, due to the large pKa value and small quadrupole moment of C2H6. Herein, we demonstrate the perfectly size matching between the ultramicropore (pore size of 4.6 Å) and ethane (kinetic diameter of 4.4 Å) in a nickel pyridine-4-carboxylate metal–organic framework (IISERP-MOF 2 ), which enables the record-breaking performance for low concentration C2H6 capture. IISERP-MOF 2 exhibits the large C2H6 adsorption enthalpy of 56.7 kJ/mol, and record-high C2H6 uptake at low pressure of 0.01–0.1 bar and 298 K (1.8 mmol/g at 0.01 bar). Molecule simulations and C2H6-loading crystal structure analysis revealed that the maximized interaction sites in IISERP-MOF 2 with ethane molecule originates the strong C2H6 adsorption. The dynamic breakthrough experiments for gas mixtures of C2H6/N2(1/999, v/v) and C2H6/CH4 (5/95, v/v) proved the excellent low-concentration C2H6 capture performance. 相似文献
8.
Yan-Xi Tan Jing Lin Prof. Qiao-Hong Li Liqiong Li Rahul Anil Borse Prof. Weigang Lu Prof. Yaobing Wang Prof. Daqiang Yuan 《Angewandte Chemie (International ed. in English)》2023,62(22):e202302882
Designing porous materials for C2H2 purification and safe storage is essential research for industrial utilization. We emphatically regulate the metal-alkyne interaction of PdII and PtII on C2H2 sorption and C2H2/CO2 separation in two isostructural NbO metal–organic frameworks (MOFs), Pd/Cu-PDA and Pt/Cu-PDA . The experimental investigations and systematic theoretical calculations reveal that PdII in Pd/Cu-PDA undergoes spontaneous chemical reaction with C2H2, leading to irreversible structural collapse and loss of C2H2/CO2 sorption and separation. Contrarily, PtII in Pt/Cu-PDA shows strong di-σ bond interaction with C2H2 to form specific π-complexation, contributing to high C2H2 capture (28.7 cm3 g−1 at 0.01 bar and 153 cm3 g−1 at 1 bar). The reusable Pt/Cu-PDA efficiently separates C2H2 from C2H2/CO2 mixtures with satisfying selectivity and C2H2 capacity (37 min g−1). This research provides valuable insight into designing high-performance MOFs for gas sorption and separation. 相似文献
9.
C2(a 3πu) disappearance rate constants of 1.44, 0.96, 0.0296, 0.0130 and < 10?6(x10?10cm3s?1) are reported for reactions with C2H4, C2H2, O2, C2H6, and CH4, respectively at 298 K. C2(a 3πu) fragments are generated by multiphoton ArF excimer laser photodissociation at C2H2, and monitored by dye laser induced fluorescence. Arguments are presented which favor chemical reactions over the C2(a 3πu) → (X 1σ+g) quenching channel. C2 + C2H2 represents the one possible exception to the reactive channel. 相似文献
10.
Richard B. Pardy Michael J. Taylor Edwin C. Constable John D. Mersh Jeremy N.M. Sanders 《Journal of organometallic chemistry》1982,231(2):c25-c30
Reversible protonation of the bis-ethylene complex, Co(C5Me4Et)(C2H4)2 yields [Co(C5Me4Et)(C2H4)2H][BF4], which readily exchanges its hydridic and olefinic protons stereospecifically at low temperatures; subsequent protonation at room temperature yields cobalt(III) complexes, C2H4 and C2H6. 相似文献
11.
R. Peyton Thorn Walter A. Payne Xavier D. F. Chillier Louis J. Stief Fred L. Nesbitt D. C. Tardy 《国际化学动力学杂志》2000,32(5):304-316
The total rate constant k1 has been determined at P = 1 Torr nominal pressure (He) and at T = 298 K for the vinyl‐methyl cross‐radical reaction: (1) CH3 + C2H3 → Products. The measurements were performed in a discharge flow system coupled with collision‐free sampling to a mass spectrometer operated at low electron energies. Vinyl and methyl radicals were generated by the reactions of F with C2H4 and CH4, respectively. The kinetic studies were performed by monitoring the decay of C2H3 with methyl in excess, 6 < [CH3]0/ [C2H3]0 < 21. The overall rate coefficient was determined to be k1(298 K) = (1.02 ± 0.53) × 10−10 cm3 molecule−1 s−1 with the quoted uncertainty representing total errors. Numerical modeling was required to correct for secondary vinyl consumption by reactions such as C2H3 + H and C2H3 + C2H3. The present result for k1 at T = 298 K is compared to two previous studies at high pressure (100–300 Torr He) and to a very recent study at low pressure (0.9–3.7 Torr He). Comparison is also made with the rate constant for the similar reaction CH3 + C2H5 and with a value for k1 estimated by the geometric mean rule employing values for k(CH3 + CH3) and k(C2H3 + C2H3). Qualitative product studies at T = 298 K and 200 K indicated formation of C3H6, C2H2, and C3H5 as products of the combination‐stabilization, disproportionation, and combination‐decomposition channels, respectively, of the CH3 + C2H3 reaction. We also observed the secondary C4H8 product of the subsequent reaction of C3H5 with excess CH3; this observation provides convincing evidence for the combination‐decomposition channel yielding C3H5 + H. RRKM calculations with helium as the deactivator support the present and very recent experimental observations that allylic C‐H bond rupture is an important path in the combination reaction. The pressure and temperature dependencies of the branching fractions are also predicted. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 304–316, 2000 相似文献
12.
Ab initio calculations at the SCF and Cl level have been carried out for the singlet ground state of ortho-benzyne (1,2,-dehydrobenzene) at a variety of C2v molecular geometries. The principal features of the equilibrium geometry are: (1) an “acetylenic” C1C2 bond (1.22 Å): (2) a C4C5 bond slightly elongated (1.42 Å) with respect to benzene; (3) no elongation of the C2C3 and C1C6 bonds, due to the high s-character and angular deviation of the hybrid orbitals. Extended basis SCF calculations lead to an estimate of ≈ 120 kcal/mole for the ΔH298°f of o-benzyne. 相似文献
13.
Hydration
behavior of dicalcium silicate (C2S) (Cement chemistry
nomenclature is used where C=CaO, S=SiO2, A=Al2O3,
S=SO3) and gehlenite (C2AS),
synthesized by sol–gel method was investigated by means of isothermal
heat flow calorimeter at different temperatures. These phases were obtained
by crystallization processing at different temperatures from their xerogels
(nano-crystalline) prepared by the sol–gel method at ambient temperature.
The crystallization of C2S begins below 600°C and
it is well crystallized at 900°C. X-ray diffraction patterns reveal that
β-C2S is formed and it remains stable since after
slow cooling. The crystallization of C2AS xerogels
starts with the formation of C2S, then it reacts with
alumina to form mineral C2AS at 1100°C. The effect
of hydration temperature upon the hydration reaction of C2S
obtained at 600 and 900°C and C2AS annealed at
600 and 1100°C was investigated by means of isothermal calorimeter. An
increase in the temperature of hydration brought about initial acceleration
of all samples, as indicated by the increased magnitude of peak of calorimetric
curves. The microstructure of the samples cured at hydrothermal condition
after 1 and 7 days has been examined by means of scanning electron microscopy
(SEM). Fine crystals of calcium silicate hydrate (C–S–H) were
developed in C2S samples, while C2AS
has been hydrated to form gehlenite hydrate supplemented by C–S–H. 相似文献
14.
Equilibrium geometries of 16 possible isomers for C74(BN)2 were studied by INDO series of methods, to indicate that the most stable three geometries are those where boron and nitrogen atoms substitute carbon atoms located at the same hexagon near the longest axis of C78 (C2v) to form B-N-B-N unit. Electronic spectra of C74(BN)2 were investigated with INDO/CIS method. The reason for the red shift of UV absorptions for C74(BN)2 compared with those of C78 (C2v) was discussed. IR spectra for 9,8,28,29-C74(BN)2 and 28,29,30,31-C74(BN)2 were calculated on the basis of AM1 geometries. 相似文献
15.
N.S. Chilingarov A.V. NikitinJ.V. Rau I.V. GolyshevskyA.V. Kepman F.M. SpiridonovL.N. Sidorov 《Journal of fluorine chemistry》2002,113(2):219-226
Fluorination of C60(s), C60(s)-MnF2(s), C60(s)-NiF2(s) and C60(s)-MnF3(s) mixtures has been studied by Knudsen cell mass spectrometry with admission of molecular fluorine. The fluorination is selective when fullerene reacts with the fluorine chemisorbed on the MnF2 surface. When the MnF2 content in the initial mixture is at least 90 mol% both C60F18 and C60F36 are selectively formed. Under certain conditions, mixtures predominantly containing one of three compounds C60F38, C60F40, and C60F42 can be obtained. A consecutive change of the main fluorination products (C60F18 and C60F36) takes place at constant temperature (720 K) and on fluorine admission. A quantitative explanation of this fact is given. Selective fluorination of C60(s) by molecular fluorine is compared with solid-phase fluorination using MnF3(s) as a fluorinating agent. 相似文献
16.
Mikhayl F. Budyka Tatyana S. Zyubina Alexander G. Ryabenko 《International journal of quantum chemistry》2002,88(5):652-662
The reaction between C2 cluster and C60 fullerene resulting in C2 insertion to C60 with formation of closed C62 cage (reaction of C2 ingestion by C60) was investigated by the semiempirical MNDO‐PM3 method. The geometries and energies of extremal points on the C62 potential energy surface were calculated. Several reaction pathways leading to the formation of three different closed C62 fullerenes were investigated. All insertion reactions proceed stepwise through intermediate adducts of different structures. The main reaction pathways were found to be addition of C2 by its one side to the 6,6‐ or 5,6‐bond of C60 with formation of primary unclosed C62 adducts of “ball‐with‐fork” structures, lying in deep potential wells. Back reaction of C2 detachment from primary adducts can compete with that of their transformation to the closed C62 cages inasmuch as calculated activation barriers of the both reactions are comparable. Model calculations at the B3LYP/6‐31G* level, using C32H12 semisphere instead of C60, confirmed the conclusion about two competitive pathways of the primary adducts transformation, C2 detachment, and C2 ingestion. The concerted insertion of C2 to C60 was realized only in the case of severe restrictions on starting geometry of the C2 + C60 system. The results of calculations explain recent experimental data on the formation of metastable adducts upon addition of C2 to C60, obtained using the time‐of‐flight mass spectrometer with laser desorption. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002 相似文献
17.
《Mendeleev Communications》2022,32(5):640-641
Chlorofullerenes C84(11)Cl20 and C84(11)Cl22 were prepared by chlorination of C2–C84(11) with VCl4 at 340–360 °C. An X-ray crystallographic study with the use of synchrotron radiation revealed the chlorination patterns featuring only para additions in C6Cl2 hexagons. 相似文献
18.
Meina Wang Yingxiong Wang Defeng Yu Yuchun Han Yilin Wang 《Colloid and polymer science》2013,291(7):1613-1621
Salt effects on the aggregation behavior of tripolar zwitterionic surfactants in aqueous solutions have been investigated using surface tension, dynamic light scattering (DLS), freeze-fracture transmission electron microscopy (FF-TEM), and 1H NMR. The tripolar zwitterionic surfactants with different inter-charge spacers are [C14H29(CH3)2N+CsN+(CH3)2CH2CH2CH2SO3 ?]Br? (C14CsTri, Cs?=?–(CH2)2–, –(CH2)6–, –(CH2)10–, and p-xylyl). It is found that the critical micelle concentration (CMC) values of the corresponding traditional zwitterionic surfactant C14H29(CH3)2N+CH2CH2CH2SO3 ? (TPS) are almost constant with the increase of the NaBr concentration. However, the CMC values of C14CsTri decrease sharply at a lower NaBr concentration and then level off at a higher NaBr concentration. Moreover, the decreasing extents of the CMC values for C14C2Tri, C14C6Tri, and C14CpxTri are very close, but more significant than that for C14C10Tri, suggesting that the self-assembly ability of the tripolar zwitterionic surfactants with a longer inter-charge spacer is less sensitive to NaBr. The DLS and FF-TEM results reveal that C14C2Tri, C14C6Tri, and C14CpxTri form micelles without NaBr and that the size slightly increases with the increase of NaBr concentration, whereas micelles and vesicles coexist for C14C10Tri and TPS without NaBr and then transfer to micelles upon the addition of NaBr. The salt-induced morphological transition for C14C10Tri is further studied using 1H NMR. The addition of NaBr reduces both the electrostatic repulsion between the same charged ammoniums and the electrostatic attraction between the oppositely charged ammonium and sulfonate. Thus, the longer inter-charge spacer of C14C10Tri tends to be more bended and the sulfonate group becomes available to contact the ammonium, which promotes micellization. 相似文献
19.
A vacuum ultraviolet photolysis of C2H5Br at 147 nm was studied over a pressure range of 0.5–50 torr at 298 K. The effects of additives He and NO were also investigated. The principal reaction products were found to be C2H4 and C2H6, with lesser yields of CH4 and C2H2. With increasing pressure the product quantum yields Φi of C2H4, CH4, and CH2H6 remained constant, while that of C2H2 decreased from 0.03 to almost 0. The effect of He as an additive was found to be extremely small on the quantum yields of the major products. Addition of NO completely suppresses the formation of CH4, C2H2, and C2H6, and reduces partially the production of C2H4. The primary processes appear to involve two electronically excited states. One state mainly yields C2H4 by molecular elimination of HBr and is thought to be due to a Rydberg transition. The other state decomposes to C2H5 and Br radicals by C? Br bond fission. These two competitive reaction modes contribute to the photodecomposition in proportions of 50% and 50%. The extinction coefficient for C2H5Br at 147 nm and at 298 K has been determined as ? = (1/PL) In(Io/It) = 712 ± 7 atm?1 · cm?1. 相似文献
20.
The reaction of Au atoms with 12C2H4 or 12C2H4/Ar mixtures at 8–10 K yields a single product. Using Au and 12C2H4 concentration experiments, warm-up studies and 13C2H4/Ar, 12C2H4/13C2H4/Ar isotopic substitution, coupled with infrared and UV-visible spectroscopy, the product is characterized to be monoethylene gold(0), (C2H4)Au, the first reported example of a zerovalent gold-olefin complex. Extended Hückel molecular orbital calculations proved to be a useful aid towards the assignment of the optical spectrum of (C2H4)Au. The thermal stability of (C2H4)Au in solid C2H4 at 70 K is discussed in terms of the feasibility of a macroscale, liquid nitrogen temperature, chemical synthesis. The molecular and electronic properties of the group of complexes (C2H4)M and M(02), where M = Ag or Au, are compared and discussed. 相似文献