Theoretical investigation of supramolecular hydrogen-bonded choline chloride-based deep eutectic solvents using density functional theory

2021 ◽  
Vol 769 ◽  
pp. 138427
Author(s):  
Zubera Naseem ◽  
Rao Aqil Shehzad ◽  
Anaum Ihsan ◽  
Javed Iqbal ◽  
Muhammad Zahid ◽  
...  
Author(s):  
Huimin Guo ◽  
Xiaolin Ma ◽  
Zhiwen Lei ◽  
Yang Qiu ◽  
Bernhard Dick ◽  
...  

The electronic structure and photophysical properties of a series of N-Methyl and N-Acetyl substituted alloxazine (AZs) were investigated with extensive density functional theory (DFT) and time-dependent density functional theory (TD-DFT)...


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 926
Author(s):  
Malose J. Mphahlele ◽  
Eugene E. Onwu ◽  
Marole M. Maluleka

The conformations of the title compounds were determined in solution (NMR and UV-Vis spectroscopy) and in the solid state (FT-IR and XRD), complemented with density functional theory (DFT) in the gas phase. The nonequivalence of the amide protons of these compounds due to the hindered rotation of the C(O)–NH2 single bond resulted in two distinct resonances of different chemical shift values in the aromatic region of their 1H-NMR spectra. Intramolecular hydrogen bonding interactions between the carbonyl oxygen and the sulfonamide hydrogen atom were observed in the solution phase and solid state. XRD confirmed the ability of the amide moiety of this class of compounds to function as a hydrogen bond acceptor to form a six-membered hydrogen bonded ring and a donor simultaneously to form intermolecular hydrogen bonded complexes of the type N–H···O=S. The distorted tetrahedral geometry of the sulfur atom resulted in a deviation of the sulfonamide moiety from co-planarity of the anthranilamide scaffold, and this geometry enabled oxygen atoms to form hydrogen bonds in higher dimensions.


2019 ◽  
Vol 43 (25) ◽  
pp. 9916-9923 ◽  
Author(s):  
Jing Gao ◽  
Xin Li ◽  
Deming Han ◽  
Jiawei Li ◽  
Xiaohong Shang

The electronic structure, absorption and emission spectra, charge injection/transport ability and phosphorescence quantum efficiency of a series of cyclometalated iridium(iii) complexes with different ancillary ligands are studied using density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods.


Author(s):  
Yang Wang ◽  
Yan Qiao ◽  
Yu Lan ◽  
Donghui Wei

Using density functional theory, we investigated the origin of selectivity in the N-heterocyclic carbene (NHC)-catalyzed transformation of formylcyclopropane with an alkylidene oxindole.


2020 ◽  
Vol 17 (7) ◽  
pp. 2890-2896
Author(s):  
Yanhong Dong ◽  
Ning-Ning Wei ◽  
Liguo Gao ◽  
Juanyuan Hao ◽  
Dan Vasilescu ◽  
...  

The sensing mechanism of luminescent metal-organic framework [Zn(3-tzba)(2,2′-bipy)(H2O)] -3H2O for formaldehyde detection was explored by using density functional theory and time-dependent density functional theory methods. Our investigation found that luminescent metal-organic framework [Zn(3-tzba)(2,2′-bipy)(H2O)] • 3H2O is able to interact with formaldehyde through hydrogen bonding to the framework. The luminescent mechanism of the hydrogen-bonded complex is photo-induced electron transfer; while the luminescent mechanism of luminescent metal-organic framework [Zn(3-tzba)(2,2′-bipy)(H2O)]-3H2O is ligand-to-ligand charge transfer. The intermolecu-lar hydrogen bond was found to be stronger in the excited state than that in the ground state by analyzing the geometry nuclear magnetic resonance, binding energy and infrared spectrum in different electronic states. Calculated fluorescence radiative rate coefficient and internal conversion rate coefficient qualitatively indicated a reduced radiative process and an enhanced internal conversion process of the hydrogen-bonded complex. The hydrogen-bonded complex exhibits luminescence weakening or even quenching due to the enhancement of the intermolecular hydrogen bond in the excited state compare with luminescent metal-organic framework [Zn(3-tzba)(2,2′-bipy)(H2O)]-3H2O. The variable luminescence demonstrated the potential of luminescent metal-organic framework [Zn(3-tzba)(2,2′-bipy)(H2O)]-3H2O as luminescent sensor for formaldehyde detection.


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