共查询到20条相似文献,搜索用时 301 毫秒
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Dr. Ping Li Josef M. Maier Erik C. Vik Christopher J. Yehl Dr. Brent E. Dial Amanda E. Rickher Dr. Mark D. Smith Dr. Perry J. Pellechia Prof. Ken D. Shimizu 《Angewandte Chemie (International ed. in English)》2017,56(25):7209-7212
A series of N-arylimide molecular balances were designed to study and measure fluorine–aromatic (F–π) interactions. Fluorine substituents gave rise to increasingly more stabilizing interactions with more electron-deficient aromatic surfaces. The attractive F–π interaction is electrostatically driven and is stronger than other halogen–π interactions. 相似文献
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Ying LIU Guo Sheng DING Jun De WANG Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 《中国化学快报》2005,16(6):797-800
Molecularly imprinted polymer, exhibiting considerable enantioselectivity for L-mandelic acid, was prepared using metal coordination-chelation interaction. By evaluating the recognition characteristics in the chromatographic mode, the recognition interactions were proposed: specific and nonspecific metal coordination-chelation interaction and hydrophobic interaction were responsible for substrate binding on metal-complexing imprinted polymer; while the selective recognition only came from specific metal coordination-chelation interaction and specific hydrophobic interaction. 相似文献
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Guha S Goodson FS Corson LJ Saha S 《Journal of the American Chemical Society》2012,134(33):13679-13691
The recent emergence of anion-π interactions has added a new dimension to supramolecular chemistry of anions. Yet, after a decade since its inception, actual mechanisms of anion-π interactions remain highly debated. To elicit a complete and accurate understanding of how different anions interact with π-electron-deficient 1,4,5,8-naphthalenediimides (NDIs) under different conditions, we have extensively studied these interactions using powerful experimental techniques. Herein, we demonstrate that, depending on the electron-donating abilities (Lewis basicity) of anions and electron-accepting abilities (π-acidity) of NDIs, modes of anion-NDI interactions vary from extremely weak non-chromogenic anion-π interactions to chromogenic anion-induced charge-transfer (CT) and electron-transfer (ET) phenomena. In aprotic solvents, electron-donating abilities of anions generally follow their Lewis basicity order, whereas π-acidity of NDIs can be fine-tuned by installing different electron-rich and electron-deficient substituents. While strongly Lewis basic anions (OH(-) and F(-)) undergo thermal ET with most NDIs, generating NDI(?-) radical anions and NDI(2-) dianions in aprotic solvents, weaker Lewis bases (AcO(-), H(2)PO(4)(-), Cl(-), etc.) often require the photoexcitation of moderately π-acidic NDIs to generate the corresponding NDI(?-) radical anions via photoinduced ET (PET). Poorly Lewis basic I(-) does not participate in thermal ET or PET with most NDIs (except with strongly π-acidic core-substituted dicyano-NDI) but forms anion/NDI CT or anion-π complexes. We have looked for experimental evidence that could indicate alternative mechanisms, such as a Meisenheimer complex or CH···anion hydrogen-bond formation, but none was found to support these possibilities. 相似文献
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V. V. Burdin G. I. Voloshchenko V. D. Maiorov N. B. Librovich 《Russian Chemical Bulletin》1995,44(9):1684-1687
Multiple Attenuated Total Reflectance (MATR) IR spectra of solutions of HCl in isopropanol, containing 0 to 43 mol. % HCl, were studied in the 900–4000 cm–1 range. The addition of HCl to PriOH yields proton disolvates
with strong symmetrical H-bonds. At high concentrations of HCl (C
HCl
0 > 5.7 mol L–1,
/C0
HCl < 2), when the number of alcohol molecules is not enough to form disolvates with all of the protons present in the solution, (Cl...H...Cl)– ions are formed, in addition to (C3H7OH)2H+. The spectra of these ions have been assigned.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1753–1756, September, 1995.This work was carried out with financial support of the Russian Foundation for Basic Research (Project No. 93-03-18356). 相似文献
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聚氯乙烯燃烧特性及HCl的生成机理 总被引:14,自引:5,他引:9
采用热重法对聚氯乙烯(PVC)的燃烧过程进行了研究,探讨阳聚氯乙烯燃烧科技司,并由它们的微分热重曲线计算出的反应动力学参数及影响反应常数的因素进行了研究。同时,考察了恒速升温和快速升温过程HCI的生成特性。结果表明,PVC的燃烧机理是由三个过程决定的,可用三个一级反应表示。PVC的燃烧过程的第一阶段为脱氯阶段。第二阶段的活化能和指前因子明显低于第一和一阶段。此阶段为挥发分释放阶段。升温速率的增加导 相似文献
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The effects of the initial rotational-excited states of the HCl molecule on the stereodynamics properties of the Ca + HCl molecular reaction are investigated using the quasiclassical trajectory theory and the analytical potential energy surface. The orientation and alignment behaviors for the rotational angular momentum of the product, along with the generalized differential cross section (PDDCS)-dependent polarization, are calculated to explore the stereodynamics properties. The initial rotational-excited states of the HCl molecule impose a remarkable effect on the vector correlation distributions, regardless of the orientation, alignment, or PDDCS. The forward, backward, and weak sideway scatterings are found in the Ca + HCl → CaCl + H molecular reaction. The results demonstrate that the initial rotational-excited state of j = 3 results in more obvious stereodynamics effects. 相似文献
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C Zhao RM Parrish MD Smith PJ Pellechia CD Sherrill KD Shimizu 《Journal of the American Chemical Society》2012,134(35):14306-14309
The D/H isotope effect for the CH-π interaction was studied experimentally and computationally. First, a series of molecular balances that are very sensitive to changes in the strength of the CH-π interactions in solution were designed. Balances with deuterated and non-deuterated alkyl groups were synthesized, and their intramolecular CH-π interactions were compared. The geometries of their intramolecular CH-π and CD-π interactions were characterized in the solid state by X-ray analysis, and the strength of each interaction was characterized in solution by the folded/unfolded ratio as measured by (1)H NMR spectra. Second, the relative strengths of the CH-π and CD-π interactions were also assessed computationally using dispersion-corrected DFT (PDE-D2/6-31+G*). No significant differencee was observed in either the experimental or theoretical studies, indicating that the D/H isotope effect for the CH-π interaction is either very small or nonexistent. 相似文献
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Binding of the drug phenosafranine to hemoglobin (Hb) in aqueous solutions was investigated by fluorescence, UV/vis and circular dichroism (CD) spectral methods at pH=7.4. The fluorescence data showed that fluorescence quenching of Hb by phenosafranine is the result of formation of a phenosafranine–Hb complex with a 1:1 molar ratio. Thermodynamic analysis implied that hydrophobic, electrostatic and hydrogen bond interactions are all involved in stabilizing the complex. The molecular distance (r=4.29 nm) between the donor (Hb) and acceptor (phenosafranine) was calculated according to Förster’s theory. The features of phenosafranine-induced secondary structure changes of Hb have been studied by synchronous fluorescence, CD and three-dimensional fluorescence spectroscopy. This study improves our knowledge of the interaction dynamics of phenazinium drugs to the physiologically important protein Hb. 相似文献
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Inverse chromatography (IC) has been widely applied to characterize surface, interface, and bulk characteristics of technologically important materials. Probe molecules with known properties are injected into an isothermal chromatographic system with the material of interest as 相似文献
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Wolfgang Scherer Andrew C. Dunbar Jos E. Barquera‐Lozada Dominik Schmitz Georg Eickerling Daniel Kratzert Dietmar Stalke Arianna Lanza Piero Macchi Nicola P. M. Casati Jihaan Ebad‐Allah Christine Kuntscher 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(8):2535-2539
Square‐planar d8‐ML4 complexes might display subtle but noticeable local Lewis acidic sites in axial direction in the valence shell of the metal atom. These sites of local charge depletion provide the electronic prerequisites to establish weakly attractive 3c–2e M⋅⋅⋅H C agostic interactions, in contrast to earlier assumptions. Furthermore, we show that the use of the sign of the 1H NMR shifts as major criterion to classify M⋅⋅⋅H C interactions as attractive (agostic) or repulsive (anagostic) can be dubious. We therefore suggest a new characterization method to probe the response of these M⋅⋅⋅H C interactions under pressure by combined high pressure IR and diffraction studies. 相似文献