scholarly journals Facile Charge Transfer between Barbituric Acid and Chloranilic Acid over g-C3N4: Synthesis, Characterization and DFT Study

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 636
Author(s):  
Gaber A. M. Mersal ◽  
Mohamed M. Ibrahim ◽  
Mohammed A. Amin ◽  
Amine Mezni ◽  
Nasser Y. Mostafa ◽  
...  

The molecular complexes between barbituric acid (BU) and chloranilic acid (ChA) over graphitic nitride (g-C3N4) are investigated. The molecular complexes and the nanocomposite were investigated both in solid state and in methanol. The solid complexes and the corresponding nanocomposite were investigated using FTIR, TGA, and UV-Vis spectroscopy. The structures were explored using DFT calculations using wB97XD/ and def2-TZVP basis set. The DFT calculations revealed the formation of hydrogen-bonded complexes, which initiate the proton transfer from ChA to BU. Immobilization of the BUChA complex over the g-C3N4 sheet was stabilized by weak non-covalent interactions, such as π–π interactions. g-C3N4 facilitated the charge transfer process, which is beneficial for different applications.

2018 ◽  
Vol 71 (4) ◽  
pp. 238 ◽  
Author(s):  
Manoj K. Kesharwani ◽  
Amir Karton ◽  
Nitai Sylvetsky ◽  
Jan M. L. Martin

The S66 benchmark for non-covalent interactions has been re-evaluated using explicitly correlated methods with basis sets near the one-particle basis set limit. It is found that post-MP2 ‘high-level corrections’ are treated adequately well using a combination of CCSD(F12*) with (aug-)cc-pVTZ-F12 basis sets on the one hand, and (T) extrapolated from conventional CCSD(T)/heavy-aug-cc-pV{D,T}Z on the other hand. Implications for earlier benchmarks on the larger S66×8 problem set in particular, and for accurate calculations on non-covalent interactions in general, are discussed. At a slight cost in accuracy, (T) can be considerably accelerated by using sano-V{D,T}Z+ basis sets, whereas half-counterpoise CCSD(F12*)(T)/cc-pVDZ-F12 offers the best compromise between accuracy and computational cost.


2006 ◽  
Vol 71 (9) ◽  
pp. 1359-1370 ◽  
Author(s):  
Usama M. Rabie

Charge transfer (CT) complexes of 4-(dimethylamino)pyridine (DMAP) with iodine as a typical σ-type acceptor and with typical π-type acceptor, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), have been synthesized and characterized. Octafluorotoluene (OFT), octafluoronaphthalene (OFN), perfluorophenanthrene (PFP), and 2,3,5,6-tetrafluoropyridine-4-carbonitrile (TFP) were also used as acceptors for interaction with DMAP. Properties of such CT complexes were investigated by UV/VIS and IR spectra, and elemental analyses of the isolated complexes. The systems DMAP-iodine and DMAP-DDQ are characterized by formation of triiodide ions (I3-) and DDQ•- anion radicals, respectively, which is proposed to occur via initial formation of outer-sphere CT complexes. The systems (DMAP-OFT, DMAP-OFN, DMAP-PFP and DMAP-TFP) are characterized by the appearance of new UV/VIS spectral bands assigned as CT bands; they also furnished the corresponding solid complexes with the stoichiometric ratio 1:1. 1H and 19F NMR spectra were used on confirming the formation of the DMAP-PFP CT complexes. The formation constants (KCT) and molar absorption coefficients (εCT) of the latter complex were obtained.


2021 ◽  
Vol 3 (3) ◽  
pp. 034007
Author(s):  
Viki Kumar Prasad ◽  
Alberto Otero-de-la-Roza ◽  
Gino A DiLabio

2015 ◽  
Vol 39 (4) ◽  
pp. 2778-2794 ◽  
Author(s):  
Debanjana Biswal ◽  
Nikhil Ranjan Pramanik ◽  
Syamal Chakrabarti ◽  
Nirmalya Chakraborty ◽  
Krishnendu Acharya ◽  
...  

Fascinating supramolecular frameworks of Mo(vi) complexes.


2019 ◽  
Vol 10 (39) ◽  
pp. 9115-9124 ◽  
Author(s):  
Abraham J. P. Teunissen ◽  
Tim F. E. Paffen ◽  
Ivo A. W. Filot ◽  
Menno D. Lanting ◽  
Roy J. C. van der Haas ◽  
...  

The non-covalent interactions between two phase-transfer catalysts allow tuning of reaction kinetics from bimolecular, to pseudo 0th order, to sigmoidal. Kinetic models and DFT calculations are used to obtain detailed insight in the system.


2015 ◽  
Vol 17 (8) ◽  
pp. 5659-5669 ◽  
Author(s):  
Nicola Tasinato ◽  
Stefan Grimme

(CH2F2)2 and (SO2)2 are investigated using DFT-D3 computations, and experimental dissociation energies are determined by TDL-IR spectroscopy. DFT-D3 dramatically improves over uncorrected DFT.


2016 ◽  
Vol 14 (40) ◽  
pp. 9588-9597 ◽  
Author(s):  
Yunsheng Xue ◽  
Yuhui Wang ◽  
Zhongyan Cao ◽  
Jian Zhou ◽  
Zhao-Xu Chen

DFT calculations reveal the viability of the two possible ion pair-hydrogen bonding and Brønsted acid-hydrogen bonding dual activation modes.


2016 ◽  
Vol 15 (04) ◽  
pp. 1650029 ◽  
Author(s):  
Nuha Ahmed Wazzan

This work reports density functional theory (DFT) calculations on the molecular structures, electronic distribution, and UV-Vis and IR spectroscopy analysis of charge transfer complexes between aminopyridines (APYs), namely 2-APY, 3-APY and 4-APY, as electron-donors and some [Formula: see text]-electron-acceptors, namely chloranil (CHL), tetracyanoethylene (TCNE) and picryl chloride (PC), formed in the gas phase at the B3LYP/6-31[Formula: see text]G(d,p) method/basis set, and in chloroform at the same method/basis set using PCM as solvation model. Good correspondence was generally obtained between the calculated parameters and the experimental ones.


Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 6037
Author(s):  
Reem M. Alghanmi ◽  
Maram T. Basha ◽  
Saied M. Soliman ◽  
Razan K. Alsaeedi

UV–Vis spectroscopy was used to investigate two new charge transfer (CT) complexes formed between the K+-channel-blocker amifampridine (AMFP) drug and the two π-acceptors 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and tetracyanoethylene (TCNE) in different solvents. The molecular composition of the new CT complexes was estimated using the continuous variations method and found to be 1:1 for both complexes. The formed CT complexes’ electronic spectra data were further employed for calculating the formation constants (KCT), molar extinction coefficients (εCT), and physical parameters at various temperatures, and the results demonstrated the high stability of both complexes. In addition, sensitive spectrophotometric methods for quantifying AMFP in its pure form were proposed and statistically validated. Furthermore, DFT calculations were used to predict the molecular structures of AMFP–DDQ and AMFP–TCNE complexes in CHCl3. TD-DFT calculations were also used to predict the electronic spectra of both complexes. A CT-based transition band (exp. 399 and 417 nm) for the AMFP–TCNE complex was calculated at 411.5 nm (f = 0.105, HOMO-1 → LUMO). The two absorption bands at 459 nm (calc. 426.9 nm, f = 0.054) and 584 nm (calc. 628.1 nm, f = 0.111) of the AMFP–DDQ complex were theoretically assigned to HOMO-1 → LUMO and HOMO → LUMO excitations, respectively.


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