Time-Resolved FT-IR Study on Isotopic Exchange of Dinitrosyl Species Strongly Adsorbed on a Co-MFI Zeolite

1995 ◽  
Vol 24 (8) ◽  
pp. 729-730 ◽  
Author(s):  
Masakazu Iwamoto ◽  
Yasuyuki Hoshino
1993 ◽  
Vol 47 (9) ◽  
pp. 1382-1385 ◽  
Author(s):  
M. A. Czarnecki ◽  
N. Katayama ◽  
Y. Ozaki ◽  
M. Satoh ◽  
K. Yoshio ◽  
...  

The electric-field-induced reorientation of (S)-4-methylhexyl 4-[4-(decyloxy) phenylethynyl]-2-fluorobenzate in the Sc* phase was investigated by using an asynchronous time-resolved FT-IR technique. The band assignments were made on the basis of the polarized FT-IR spectra and FT-Raman spectrum. The time-resolved study indicates that the reorientation occurs immediately after the electric field is applied. The molecule reorients as a unit; however the rigid core of the molecule seems to be more mobile than the hydrocarbon chains and needs a shorter period of time for the reorientation. The change of orientation is not completely finished in a 500-μs time period. Of particular note is the behavior of the carbonyl band; this band, usually strong in infrared spectra, is very weak in the time-resolved spectra.


Biochemistry ◽  
2004 ◽  
Vol 43 (40) ◽  
pp. 12809-12818 ◽  
Author(s):  
Yaowu Xiao ◽  
M. Shane Hutson ◽  
Marina Belenky ◽  
Judith Herzfeld ◽  
Mark S. Braiman

1988 ◽  
Vol 27 (Part 2, No. 6) ◽  
pp. L935-L937 ◽  
Author(s):  
Hirokazu Toriumi ◽  
Hisashi Sugisawa ◽  
Hiroshi Watanabe
Keyword(s):  
Ft Ir ◽  

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaoliang Liu ◽  
Jing Shi ◽  
Guang Yang ◽  
Jian Zhou ◽  
Chuanming Wang ◽  
...  

AbstractZeolite morphology is crucial in determining their catalytic activity, selectivity and stability, but quantitative descriptors of such a morphology effect are challenging to define. Here we introduce a descriptor that accounts for the morphology effect in the catalytic performances of H-ZSM-5 zeolite for C4 olefin catalytic cracking. A series of H-ZSM-5 zeolites with similar sheet-like morphology but different c-axis lengths were synthesized. We found that the catalytic activity and stability is improved in samples with longer c-axis. Combining time-resolved in-situ FT-IR spectroscopy with molecular dynamics simulations, we show that the difference in catalytic performance can be attributed to the anisotropy of the intracrystalline diffusive propensity of the olefins in different channels. Our descriptor offers mechanistic insight for the design of highly effective zeolite catalysts for olefin cracking.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2545
Author(s):  
Luna Song ◽  
Hehe Bai ◽  
Chenyang Liu ◽  
Wenjun Gong ◽  
Ai Wang ◽  
...  

Two light-activated NO donors [RuCl(qn)(Lbpy)(NO)]X with 8-hydroxyquinoline (qn) and 2,2′-bipyridine derivatives (Lbpy) as co-ligands were synthesized (Lbpy1 = 4,4′-dicarboxyl-2,2′-dipyridine, X = Cl− and Lbpy2 = 4,4′-dimethoxycarbonyl-2,2′-dipyridine, X = NO3−), and characterized using ultraviolet–visible (UV-vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (1H NMR), elemental analysis and electrospray ionization mass spectrometry (ESI-MS) spectra. The [RuCl(qn)(Lbpy2)(NO)]NO3 complex was crystallized and exhibited distorted octahedral geometry, in which the Ru–N(O) bond length was 1.752(6) Å and the Ru–N–O angle was 177.6(6)°. Time-resolved FT-IR and electron paramagnetic resonance (EPR) spectra were used to confirm the photoactivated NO release of the complexes. The binding constant (Kb) of two complexes with human serum albumin (HSA) and DNA were quantitatively evaluated using fluorescence spectroscopy, Ru-Lbpy1 (Kb~106 with HSA and ~104 with DNA) had higher affinity than Ru-Lbpy2. The interactions between the complexes and HSA were investigated using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) and EPR spectra. HSA can be used as a carrier to facilitate the release of NO from the complexes upon photoirradiation. The confocal imaging of photo-induced NO release in living cells was successfully observed with a fluorescent NO probe. Moreover, the photocleavage of pBR322 DNA for the complexes and the effect of different Lbpy substituted groups in the complexes on their reactivity were analyzed.


2002 ◽  
Vol 56 (4) ◽  
pp. 509-514 ◽  
Author(s):  
Xiaohua Yi ◽  
Karen Nerbonne ◽  
John Pellegrino

We present an experimental method for measuring diffusion of lubricants (or any highly viscous fluid) in polymers using Fourier transform infrared (FT-IR) attenuated total reflection (ATR) spectroscopy. Unlike the conventional FT-IR ATR diffusion measurement, in which a polymer sample is sandwiched between the penetrant and an internal reflection element (IRE), in this method, a thin layer of penetrant (for example, a lubricant) is sandwiched between the IRE and the polymer sample. This allows accurate control and measurement of the thickness of the lubricant layer, which, in turn, facilitates subsequent data analysis. The diffusion is studied by monitoring the time-resolved change in absorbance of either a unique polymer or penetrant band. A feature of this new method is that it can provide an estimate of solubility, as well as an estimate of the diffusivity of the penetrant in the polymer. Using this method, we studied the diffusion of mineral oil and a commercial fluorocarbon ether lubricant (Krytox® 143AC‡) in poly(propylene) (PP) film at room temperature. The experimental data was modeled using a Fickian model with impermeable and saturated boundary conditions applied at the IRE/lubricant and lubricant/polymer interfaces, respectively. The diffusivity and solubility of mineral oil in PP were found to be 1.34 ± 0.35 (×10−10) cm2/s and 0.77 ± 0.13 (×10−2) g/g of PP, respectively. The current model was unable to quantitatively describe the diffusion of the Krytox® 143AC in the PP, possibly due to excessive swelling.


2007 ◽  
Vol 111 (7) ◽  
pp. 1517-1522 ◽  
Author(s):  
Baokang Jin ◽  
Peng Liu ◽  
Ye Wang ◽  
Zipin Zhang ◽  
Yupeng Tian ◽  
...  

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