scholarly journals Synthesis and Theoretical Calculations of 2-(p-Tolyl)-2,3-Dihydro-1H-Perimidine using Density Functional Theory

2021 ◽  
Vol 18 (1) ◽  
pp. 75-85
Author(s):  
Vishnu A. Adole ◽  
Ganesh B. Yelmame

In the present study, 2-(p-tolyl)-2,3-dihydro-1H-perimidine (TDHP) is synthesized from 1,8-naphthalenediamine and 4-methylbenzaldehyde by embedding a one-carbon unit between the nitrogen followed by ring closure using green chemistry approach. 1H NMR and 13C NMR spectral techniques were used to validate the structure of the TDHP. The synthesized perimidine TDHP is studied using density functional theory (DFT) to provide valuable insights into structural, chemical, and thermochemical study.The structural and chemical properties of TDHP were computed using the DFT method on the B3LYP/6-311G(d,p) basis package. Bond lengths were predicted from the optimised molecular structure, and the physical and chemical properties of the molecules were inferred as a consequence. The HOMO and LUMO are computed, and quantum chemical parameters are determined using electronic energies. The calculated HOMO-LUMO energy gap is 4.25 eV indicating charge transfer phenomenon within the molecule. The electron density and chemical behaviour of the TDHP was predicted using Mulliken atomic charges and the molecular electrostatic surface potential plot.Amongst all carbon atoms, the C8 carbon as more positive and C27 as more negative carbon atoms. The high global electrophilicity index suggests electrophilic character of the TDHP.The harmonic vibrational frequencies were used to measure total energy, total molar entropy, and molar heat capacity.

2020 ◽  
Author(s):  
Saeedeh Mohammadi ◽  
Mohammad Esmailpour ◽  
Mina Mohammadi

Abstract This paper is a new step in helping the treatment of coronavirus by improving the performance of chloroquine drug. For this purpose, we propose a complex of chloroquine drug with graphene nanoribbon (GNR) scheme. We compute the structural and electrical properties and absorption of chloroquine (C18H26ClN3) and GNR complex using the density functional theory (DFT) method. By creating a drug and GNR complex, the density of states of electrons increases and the energy gap decreases compared to the chloroquine. Also, using absorption calculations and spectrums such as infrared and UV-Vis spectra, we showed that GNR is a suitable structure for creating chloroquine drug complex. Our results show that the dipole moment, global softness and electrophilicity for the drug complex increases compared to the non-complex state. Our calculations can be useful for increasing performance and reducing the side effects of chloroquine, and thus can be effective in treating coronavirus.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ali I. Ismail

Ibrutinib, a Bruton’s tyrosine kinase that plays an essential role in the B-cell development and cancer cells, has been recently approved to treat chronic, lymphocytic, and other types of leukemia. This study focused on investigating ibrutinib by its electronic transitions, vibrational frequencies, and electrospray mass spectra. The experimental peaks for electronic spectrum were found at 248.0 and 281.0 nm, whereas the νC = 0 stretching frequency was found at 1652.4 and 1639.19 cm−1. These experimental properties were compared with the corresponding theoretical calculations in which density functional theory was applied. The optimized structure was obtained with the calculations using a hybrid function (B3LYP) and high-level basis sets [6-311G++(d,p)]. Most of the calculated vibrational frequencies showed a relatively good agreement with the experimental ones. The electronic transitions of ibrutinib calculated using time-dependent DFT method were performed at two different solvation methods: PCM and SMD. The mass spectrum of ibrutinib, its fragments, and its isotopic pattern agreed well with the expected spectra.


Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 359 ◽  
Author(s):  
Hanwei Li ◽  
Mingliang Luo ◽  
Guohong Tao ◽  
Song Qin

Computational investigations on the bisphospholanoethane (BPE)-ligated Cu-catalyzed enantioselective addition of enynes to ketones were performed with the density functional theory (DFT) method. Two BPE-mesitylcopper (CuMes) catalysts, BPE-CuMes and (S,S)-Ph-BPE–CuMes, were employed to probe the reaction mechanism with the emphasis on stereoselectivity. The calculations on the BPE-CuMes system indicate that the active metallized enyne intermediate acts as the catalyst for the catalytic cycle. The catalytic cycle involves two steps: (1) ketone addition to the alkene moiety of the metallized enyne; and (2) metallization of the enyne followed by the release of product with the recovery of the active metallized enyne intermediate. The first step accounts for the distribution of the products, and therefore is the stereo-controlling step in chiral systems. In the chiral (S,S)-Ph-BPE–CuMes system, the steric hindrance is vital for the distribution of products and responsible for the stereoselectivity of this reaction. The steric hindrance between the phenyl ring of the two substrates and groups at the chiral centers in the ligand skeleton is identified as the original of the stereoselectivity for the titled reaction.


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.


2020 ◽  
Vol 32 (10) ◽  
pp. 2545-2552
Author(s):  
Poodari Sumalatha ◽  
Mannam Subbarao

The primary aim of this study is to show the importance of molecular structure analysis of pharmaceutical active coumarins compounds using quantum chemistry methods based on density functional theory. To explore the theoretical calculations for global descriptors, the standard Gaussian 09W program was used for coumarins compounds. The full geometry optimization was carried out by the B3LYP/6-311G level of theory. The octanol-water and air-water partition coefficients were also estimated using functional density theory. The order of the HOMO-LUMO energy gap for studied coumarins in the gas phase is umbelliferone (UBA) < (herniarin) HNR ~ (crenulatin) CNT < (scopoletin) SCT < (scoparone) SCO < (isoscopoletin) IST < (4-methylesculetin) MST < (umbelliferone-2- carboxylic acid) UCA < (isofraxidin) IFD < (fraxetin) FXT < (aesculetine) ACT < (dapnetine) DPT. Therefore, UBA molecule in gas phase is less stable. Compared to the measured index of electrophilicity (DE). The MST molecule is stronger, more reactive, nucleophile electrophile at the gas phase and in solvents. In all solvent phases, CNT and UCA molecules have lower values, which mean they are strong nucleophiles. From the log P values of ACT and MST coumarins are in between 1.35-1.8, so ACT and MST coumarins use oral and intestinal absorptions.


2017 ◽  
Vol 95 (3) ◽  
pp. 303-314 ◽  
Author(s):  
Dan Lehnherr ◽  
Matthias Adam ◽  
Adrian H. Murray ◽  
Robert McDonald ◽  
Frank Hampel ◽  
...  

Pentacenes bearing electron-donating and (or) -withdrawing groups, namely methoxy-, dialkylamino-, and nitroaryl moieties, are synthesized to afford polarized pentacenes. The optical, electrochemical, and chemical properties of these derivatives are explored. The cycloaddition reaction of selected derivatives with tetracyanoethylene (TCNE) is explored, and the experimental results are rationalized on the basis calculations using density functional theory (DFT). X-ray crystallographic data provides insight into the molecular structure and intermolecular interactions present in the solid state.


2017 ◽  
Vol 19 (23) ◽  
pp. 15484-15502 ◽  
Author(s):  
Anderson S. Chaves ◽  
Maurício J. Piotrowski ◽  
Juarez L. F. Da Silva

Subnanometric transition-metal (TM) clusters have attracted great attention due to their unexpected physical and chemical properties, leastwise compared to their bulk counterparts.


2017 ◽  
Vol 46 (2) ◽  
pp. 529-538 ◽  
Author(s):  
Yunguo Li ◽  
Pavel A. Korzhavyi

The electronic structure and chemical bonding of Cu(i) compounds with O and/or H are investigated using ab initio calculations based on density functional theory.


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