Experimental (FTIR, BDS) and theoretical analysis of mutarotation kinetics of d-fructose mixed with different alcohols in the supercooled region

RSC Advances ◽  
2016 ◽  
Vol 6 (62) ◽  
pp. 57634-57646 ◽  
Author(s):  
M. Dulski ◽  
A. Cecotka ◽  
S. N. Tripathy ◽  
A. Sakalouski ◽  
K. Wolnica ◽  
...  

The mutarotation kinetics of pure molten d-fructose and its binary mixture with alcohols (i.e., sorbitol and maltitol) have been reported using Fourier transform infrared, broadband dielectric spectroscopy and density functional theory calculations.

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2560
Author(s):  
Jianwen Meng ◽  
Yong Pan ◽  
Fan Yang ◽  
Yanjun Wang ◽  
Zhongyu Zheng ◽  
...  

The thermal stability and decomposition kinetics analysis of 1-alkyl-2,3-dimethylimidazole nitrate ionic liquids with different alkyl chains (ethyl, butyl, hexyl, octyl and decyl) were investigated by using isothermal and nonisothermal thermogravimetric analysis combined with thermoanalytical kinetics calculations (Kissinger, Friedman and Flynn-Wall-Ozawa) and density functional theory (DFT) calculations. Isothermal experiments were performed in a nitrogen atmosphere at 240, 250, 260 and 270 °C. In addition, the nonisothermal experiments were carried out in nitrogen and air atmospheres from 30 to 600 °C with heating rates of 5, 10, 15, 20 and 25 °C/min. The results of two heating modes, three activation energy calculations and density functional theory calculations consistently showed that the thermal stability of 1-alkyl-2,3-dimethylimidazolium nitrate ionic liquids decreases with the increasing length of the alkyl chain of the substituent on the cation, and then the thermal hazard increases. This study could provide some guidance for the safety design and use of imidazolium nitrate ionic liquids for engineering.


2003 ◽  
Vol 57 (8) ◽  
pp. 970-976 ◽  
Author(s):  
M. Bolboaca ◽  
T. Stey ◽  
A. Murso ◽  
D. Stalke ◽  
W. Kiefer

Fourier transform (FT) Raman and infrared spectroscopy in combination with density functional theory calculations have been applied to the vibrational characterization of the dimeric zinc diphenylphosphanyl(trimethylsilyl)amide complex [(Me3Si)2NZnPh2PNSiMe3]2 and the ortho-metallated species [Li( o-C6H4PPh2NSiMe3)]2·Et2O in relation to their parent starting materials diphenylphosphanyl (trimethylsilyl)amine Ph2P–N(H)SiMe3 and iminophosphorane Ph3P=NSiMe3. The spectroscopic changes evidenced in the spectra were correlated with the structural parameters in order to provide insight as to what extent the P–N bond is affected by the coordination to the metal center. The employment of density functional theory (DFT) calculations in addition to these spectroscopic methods offers the possibility of predicting whether the Lewis-basic imido nitrogen atom is involved in coordination not only in the solid state, but also in the gas phase.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Natalia Piergies ◽  
Edyta Proniewicz

We present the first Fourier-transform infrared absorption (FT-IR) and Fourier-transform Raman (FT-Raman) analysis of vibrational structure of [N-phenylamino(2-boronphenyl)-R-methyl]phosphonic acid ([PhN-(2-PhB(OH)2)-R-Me]PO3H2). Assignments of experimental wavenumbers are based on performed theoretical calculations using density functional theory (DFT). Theoretical calculations show that the most stable structure of the investigated molecule is dimer incis-transconformation created by a pair of intermolecular hydrogen bonds between the boron hydroxyl groups of two monomers.


2021 ◽  
Author(s):  
Kaifa Lu ◽  
Guanru Chang ◽  
Hui Zhang ◽  
Xin-Yao Yu

By combining density functional theory calculations and experiments, we have demonstrated that the decoration of RuO2 can effectively accelerate the oxygen evolution reaction kinetics of Co3O4 in neutral electrolyte.


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