Investigation of charge transfer complexes formed between (S, S)-bis-N,N-sulfonyl bis-L-phenylalanine dimethylester donor with tetracyanoethylene and chloranil as π-acceptors: Experimental and DFT studies

2016 ◽  
Vol 15 (01) ◽  
pp. 1650009 ◽  
Author(s):  
Messaouda Mohamdi ◽  
Nadjia Bensouilah ◽  
Mohamed Abdaoui

Two novel charge transfer complexes CTC ([D[Formula: see text]TCNE] and [D[Formula: see text]CHL] : D [Formula: see text] (S, S)-bis-N,N-sulfonyl bis-L-phenylalanine dimethylester; TCNE [Formula: see text] Tetracyanoethylene; CHL [Formula: see text] Chloranil) were synthesized and characterized by elemental analysis: Electronic absorption, spectrophotometric titration, IR. The obtained results indicate the formation of 1:1 for both complexes. The experimental studies were complemented by quantum chemical calculations at DFT/CAM-B3LYP level of theory. Optimized geometrical structures, the electronic spectroscopy, excited-state properties and the descriptions of frontier molecular orbitals were computed and discussed by time-dependent density functional theory (TD-DFT). In addition, vibrational frequency calculations, the natural population analysis (NPA) confirms the presence of intermolecular interactions and natural bonding orbitals (NBO) calculation was carried out in order to elucidate the interactions between TCNE [Formula: see text]-acceptor and donor molecule.

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5970
Author(s):  
Nabil Al-Zaqri ◽  
Mohammed Suleiman ◽  
Anas Al-Ali ◽  
Khaled Alkanad ◽  
Karthik Kumara ◽  
...  

The exo⇔endo isomerization of 2,5-dimethoxybenzaldehyde was theoretically studied by density functional theory (DFT) to examine its favored conformers via sp2–sp2 single rotation. Both isomers were docked against 1BNA DNA to elucidate their binding ability, and the DFT-computed structural parameters results were matched with the X-ray diffraction (XRD) crystallographic parameters. XRD analysis showed that the exo-isomer was structurally favored and was also considered as the kinetically preferred isomer, while several hydrogen-bonding interactions detected in the crystal lattice by XRD were in good agreement with the Hirshfeld surface analysis calculations. The molecular electrostatic potential, Mulliken and natural population analysis charges, frontier molecular orbitals (HOMO/LUMO), and global reactivity descriptors quantum parameters were also determined at the B3LYP/6-311G(d,p) level of theory. The computed electronic calculations, i.e., TD-SCF/DFT, B3LYP-IR, NMR-DB, and GIAO-NMR, were compared to the experimental UV–Vis., optical energy gap, FTIR, and 1H-NMR, respectively. The thermal behavior of 2,5-dimethoxybenzaldehyde was also evaluated in an open atmosphere by a thermogravimetric–derivative thermogravimetric analysis, indicating its stability up to 95 °C.


2014 ◽  
Vol 13 (11) ◽  
pp. 1549-1560 ◽  
Author(s):  
Divya Sharma ◽  
Martin J. Paterson

MP2, DFT and TD-DFT applied to benzene–(water)6 clusters show how both perturb the electronic spectra of each other and give rise to new charge transfer features from the benzene to the water cluster.


Micro ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 140-150
Author(s):  
Navaratnarajah Kuganathan ◽  
Sashikesh Ganeshalingam

Functionalisation of single-walled carbon nanotubes (SWNTs) with atoms and molecules has the potential to prepare charge–transfer complexes for numerous applications. Here, we used density functional theory with dispersion correction (DFT + D) to examine the encapsulation and adsorption efficacy of single-walled carbon nanotubes to trap halogens. Our calculations show that encapsulation is exoergic with respect to gas-phase atoms. The stability of atoms inside SWNTs is revealed by the charge transfer between nanotubes and halogens. Encapsulation of halogens in the form of diatomic molecules is favourable with respect to both atoms and diatomic molecules as reference states. The adsorption of halogens on the outer surfaces of SWNTs is also exothermic. In all cases, the degree of encapsulation, adsorption, and charge transfer is reflected by the electronegativity of halogens.


2011 ◽  
Vol 110-116 ◽  
pp. 315-320
Author(s):  
M. R. Sonawane ◽  
B. J. Nagare

We report reactivity of silicon doped single walled carbon nanotube (Si-CNT) towards the small atmospheric gas molecules O2, CO2, SO2and NO2using density functional theory based on the numerical basis set method. The reactivity of these molecules is explained on the basis of electronic properties such as binding energy, charge density, charge transfer and density of states. The large change in binding energy and formation of sigma (σ) bonds between silicon and oxygen atoms shows the strong chemisorption of the molecules on Si-CNT. Further, the density of states analysis clearly illustrate the reduction in the band gap and creation of extra state near the Fermi level, which acts as a catalytic center for adsorption of the molecules. The Mulliken population analysis indicates the charge transfer from Si-CNT to the molecules due to their more electronegativity.


2017 ◽  
Vol 73 (6) ◽  
pp. 486-491 ◽  
Author(s):  
Rong-Er Shou ◽  
Li Song ◽  
Wen-Xiang Chai ◽  
Lai-Shun Qin ◽  
Tian-Gen Wang

Luminescent CuI complexes have emerged as promising substitutes for phosphorescent emitters based on Ir, Pt and Os due to their abundance and low cost. The title heteroleptic cuprous complex, [9,9-dimethyl-4,5-bis(diphenylphosphanyl)-9H-xanthene-κ2 P,P](2-methylquinolin-8-ol-κ2 N,O)copper(I) hexafluorophosphate, [Cu(C10H9NO)(C39H32OP2)]PF6, conventionally abbreviated as [Cu(Xantphos)(8-HOXQ)]PF6, where Xantphos is the chelating diphosphine ligand 9,9-dimethyl-4,5-bis(diphenylphosphanyl)-9H-xanthene and 8-HOXQ is the N,O-chelating ligand 2-methylquinolin-8-ol that remains protonated at the hydroxy O atom, is described. In this complex, the asymmetric unit consists of a hexafluorophosphate anion and a whole mononuclear cation, where the CuI atom is coordinated by two P atoms from the Xantphos ligand and by the N and O atoms from the 8-HOXQ ligand, giving rise to a tetrahedral CuP2NO coordination geometry. The electronic absorption and photoluminescence properties of this complex have been studied on as-synthesized samples, whose purity had been determined by powder X-ray diffraction. In the detailed TD–DFT (time-dependent density functional theory) studies, the yellow emission appears to be derived from the inter-ligand charge transfer and metal-to-ligand charge transfer (M+L′)→LCT excited state (LCT is ligand charge transfer).


2021 ◽  
Author(s):  
Zahraa A. M. Abo-Ayad ◽  
Mohamed A. Zayed ◽  
Mahmoud A Noamaan

Abstract The importance of this study stems from, it concentrates on new approach applying both practical and theoretical aspects to study structure stability of Direct orange dye 26 (DO26) as an important dye widely used for dyeing of cotton or viscose for red orange direct printing. The stable dyes are so difficult to remove, decolorized and/ or degrade, in pure solution or in wastewater samples, without using powerful removal environmental techniques electrochemical oxidations suggest and efficiently used in our Lab. Therefore, it is very important to compare between practical thermal and mass results as efficient techniques in studying dye stability, in comparison with theoretical results using Gaussian program for structural stability identification of DO26 dye, via careful inspection of various phenomena detected in its two symmetrical arms around urea center. Direct orange dye 26 (DO26) structure has been studied applying both practical spectroscopic and theoretical investigations. DFT-B3LYP/6-311++G(d,p) calculations and the electronic vibrational properties are performed to investigate its structure stability and consequently its degradation and removal from its environmental media. Correlation is found between experimental and calculated data. An intra-molecular hydrogen bonding interaction had been detected and characterized in dye skeleton. The hydrogen bonding present in the dye structure affecting its vibrational properties had been discussed. Natural population analysis like HOMO and LUMO and high quality molecular electrostatic potential plots along with various electronics had been presented at the same level of theory. Chemical reactivity descriptors from conceptual density functional theory point of view, structure activity relationship descriptor were obtained. The experimental UV/Visible, FT-IR, mass and GC-mass spectral data of the dye DO26 (D1) had been presented. These data had been supported by TD-DFT calculations to simulate the experimental spectra with computing the natural transition orbitals (NTO) and the orbital composition. The variation of charge transfer length (Δr) and variation in its dipole moment with respect to ground state (ΔmCT) had been computed in order to study the charge redistribution due to the excitations. Actually there is a problem that, degradation of this dye in wastewater by different techniques leads to various unknown fragments but on using theoretical possibilities it can be expected what happened in practical work.


2018 ◽  
Vol 18 (2) ◽  
pp. 195 ◽  
Author(s):  
Wahyu Tri Cahyanto ◽  
Aris Haryadi ◽  
Sunardi Sunardi ◽  
Abdul Basit ◽  
Yulin Elina

We report the different way to explain the nature of water molecule (H2O) adsorption on the platinum (Pt) surfaces with low Miller index, i.e., (100), (110) and (111). Here, we perform periodic density functional theory (DFT) calculations to analyze the correlation between water-surface bonding strength and the observed charge transfer occurring in the systems. The results show that Pt-H2O interaction strength at the most stable adsorption sites, i.e., the atop site for each surfaces, follows the order of H2O/Pt(110) > H2O/Pt(100) > H2O/Pt(111). This order has the same pattern with the order of observed charge transfer contributed to the bonding formation. The differences in adsorption geometrical structures in these three surfaces are suggested to responsible for the order of bond strength since Coulomb interaction plays dominant roles in our electrostatic model. Furthermore, H2O-Pt interaction mechanism, which occurs through water 3a1 orbital releasing electron density (charge) followed by Pt-O bonding formation, is clarified.


Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6391
Author(s):  
Roman Linko ◽  
Michael Ryabov ◽  
Pavel Strashnov ◽  
Pavel Dorovatovskii ◽  
Victor Khrustalev ◽  
...  

Understanding the interactions of organic donor and acceptor molecules in binary associates is crucial for design and control of their functions. Herein, we carried out a theoretical study on the properties of charge transfer complexes of 1,3,6-trinitro-9,10-phenanthrenequinone (PQ) with 23 aromatic π-electron donors. Density functional theory (DFT) was employed to obtain geometries, frontier orbital energy levels and amounts of charge transfer in the ground and first excited states. For the most effective donors, namely, dibenzotetrathiafulvalene, pentacene, tetrathiafulvalene, 5,10-dimethylphenazine, and tetramethyl-p-phenylenediamine, the amount of charge transfer in the ground state was shown to be 0.134−0.240 e−. Further, a novel charge transfer complex of PQ with anthracene was isolated in crystalline form and its molecular and crystal structure elucidated by single-crystal synchrotron X-ray diffraction.


2018 ◽  
Vol 83 (2) ◽  
pp. 139-155 ◽  
Author(s):  
Nevena Prlainovic ◽  
Milica Rancic ◽  
Ivana Stojiljkovic ◽  
Jasmina Nikolic ◽  
Sasa Drmanic ◽  
...  

The substituent and solvent effects on solvatochromism in 3-[(4-substituted) phenylamino]isobenzofuran-1(3H)-ones were studied using experimental and theoretical methodologies. The effect of specific and non-specific solvent?solute interactions on the shifts of UV?Vis absorption maxima were evaluated using the Kamlet?Taft and Catal?n solvent parameter sets. The experimental results were studied by density functional theory (DT) and time-dependent density functional theory (TD-DFT). The HOMO/LUMO energies (EHOMO/ELUMO) and energy gap (Egap) values, as well as the mechanism of electronic excitations and the changes in the electron density distribution in both ground and excited states of the investigated molecules were studied by calculation in the gas phase. The electronic excitations were calculated by the TD-DFT method in the solvent methanol. It was found that both substituents and solvents influence the degree of ?-electron conjugation of the synthesized molecules and affect the intramolecular charge transfer character.


2011 ◽  
Vol 474-476 ◽  
pp. 720-724
Author(s):  
Dong Mei Bi ◽  
Liang Qiao ◽  
Xiao Ying Hu ◽  
Wen Zhi

The geometrical structures, the electronic structures, and the NH3adsorption properties of pure and B-doped graphene have been investigated using density-functional theory. The density of states (DOS) of pure and B-doped graphene, the adsorption configurations and the adsorption energies of NH3adsorbed on pure and B-doped graphene, and the charge transfer between NH3and B-doped graphene have been calculated in details. The results indicate that boron doping can enhance the DOS at the Fermi level and slightly enhance the physical adsorption of NH3on the surface of graphene. Furthermore, the doping of boron can result in the charge redistribution of graphene, which can induce the charge transfer between NH3and graphene and change the transport properties of graphene.


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