scholarly journals Vibrational Spectral Studies, Quantum Mechanical Properties, and Biological Activity Prediction and Inclusion Molecular Self-Assembly Formation of N-N’-Dimethylethylene Urea

2021 ◽  
Vol 12 (3) ◽  
pp. 3996-4017
Keyword(s):  
Self Assembly ◽  
Interaction Analysis ◽  
Noncovalent Interaction ◽  
Potential Energy Distribution ◽  
Spectral Studies ◽  
Quantum Mechanical ◽  
Ft Ir ◽  
Reduced Density Gradient ◽  
Localized Orbital ◽  
Reduced Density

A cyclic urea analog, N-N'-dimethylethylene urea, was studied using different spectral methods like FT-IR, FT-Raman, and UV-VIS methods followed by computational simulations. The experimental and simulated spectra are compared, and a detailed assignment of vibrations and potential energy distribution is made. It was followed by various quantum mechanical studies like frontier orbital analysis, energy descriptors, average local ionization energies, and nonlinear optical properties. The NBO gave an insight into the various intramolecular stabilizing electron delocalization by hyperconjugation. Noncovalent interaction analysis provided various types of interactions present in the molecule. We also studied ALIE, local information entropy, electron localized function, reduced density gradient studies, localized orbital locator studies, and other analyses. Molecular docking results indicated that this urea derivative acted as an ATP-hydrolysing inhibitor, and the drug delivery ability of cyclodextrin on NND was tested by forming an inclusion complex with both compounds with dispersion and without dispersion interaction.

The study of interactions with a halogen atom: influence of NH2group insertion on the crystal structures ofmeta-bromonitrobenzene derivatives

2018 ◽  
Vol 74 (11) ◽  
pp. 1509-1517 ◽  
Author(s):  
Paulina H. Marek ◽  
Mateusz Urban ◽  
Izabela D. Madura
Keyword(s):  
Crystal Structures ◽  
Molecular Crystals ◽  
Noncovalent Interaction ◽  
Hirshfeld Surface ◽  
Potential Surfaces ◽  
Acta Cryst ◽  
Reduced Density Gradient ◽  
Reduced Density ◽  
Structure Stabilization ◽  
Electron Donating Groups

Halogen atoms in molecular crystals may be involved in various interactions, often playing a very important role in structure stabilization. By introducing electron-donating groups, such as NH2, the electron density of the molecule is changed and thus interactions with the bromine substituent may alter. Herein, the crystal structures ofmeta-bromonitrobenzene and its NH2-substituted derivatives are analyzed. In all four described structures, namelym-bromonitrobenzene [Charlton & Trotter (1963).Acta Cryst.16, 313], 4-bromo-2-nitroaniline (C6H5BrN2O2,1), 2-bromo-6-nitroaniline (2) and 2-bromo-4-nitroaniline [Arshadet al.(2009).Acta Cryst.E65, o480], the Br atom is engaged in different interactions (Br...π, Br...O, Br...Br and C—H...Br, respectively). The Hirshfeld surface analysis (HS) and Reduced Density Gradient NonCovalent Interaction (RDG NCI) plots are used to prove the relevance, directionality and stabilizing nature of these interactions. Their modifications have been associated with the position of the amino group in the molecular structure and its influence on charge distribution analyzed with electrostatic potential surfaces (EPS). The diversification of the interactions has been correlated with a σ-hole potential value that enables a switching of the Br-atom character from electrophilic to nucleophilic.

Elucidation of hydrogen bonding formation by a computational, FT-IR spectroscopic and theoretical study between benzyl alcohol and isomeric cresols

RSC Advances ◽  
2016 ◽  
Vol 6 (33) ◽  
pp. 27335-27348 ◽  
Author(s):  
M. Raveendra ◽  
M. Chandrasekhar ◽  
C. Narasimharao ◽  
L. Venkatramanna ◽  
K. Siva Kumar ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Benzyl Alcohol ◽  
Density Gradient ◽  
Excess Volume ◽  
Theoretical Study ◽  
Graphical Representation ◽  
Ft Ir ◽  
Reduced Density Gradient ◽  
Reduced Density ◽  
Ir Spectroscopic

The effect of hydrogen bonding on excess volumes: the graphical representation of excess volume and reduced density gradient scattered plot of benzylalcohol with o-cresol.

NCImilano: an electron-density-based code for the study of noncovalent interactions

2013 ◽  
Vol 46 (5) ◽  
pp. 1513-1517 ◽  
Author(s):  
Gabriele Saleh ◽  
Leonardo Lo Presti ◽  
Carlo Gatti ◽  
Davide Ceresoli
Keyword(s):  
Solid State ◽  
Gas Phase ◽  
Noncovalent Interactions ◽  
Real Space ◽  
Quantum Mechanical ◽  
Solid State Electron ◽  
X Ray ◽  
Reduced Density Gradient ◽  
Reduced Density ◽  
First Time

NCImilano, a Fortran90 code for applying the reduced density gradient (RDG) descriptor to a real-space study of noncovalent interactions, is presented. This code has been specifically designed for the X-ray charge density community, as it can deal with both gas-phase and solid-state electron densities as evaluated by popular multipolar (XD2006) and Gaussian-based quantum mechanical (Gaussian03/09,CRYSTAL) computational platforms. Moreover, it implements for the first time the possibility of plotting energy densities over RDG isosurfaces.

Density functional theory, Comparative vibrational spectroscopic studies, HOMO-LUMO, and NBO analysis of Trichloro isocyanuric acid and Trithio cyanuric acid

2015 ◽  
Vol 8 (3) ◽  
pp. 2197-2221
Author(s):  
Theraviyum Chithambarathanu ◽  
M. Darathi ◽  
J. DaisyMagdaline ◽  
S. Gunasekaran
Keyword(s):  
Density Functional ◽  
Cyanuric Acid ◽  
Nbo Analysis ◽  
Basis Set ◽  
Potential Energy Distribution ◽  
Point Energy ◽  
Isocyanuric Acid ◽  
Ft Ir ◽  
Homo Lumo ◽  
Ft Raman

The molecular vibrations of Trichloro isocyanuric acid (C3Cl3N3O3) and Trithio cyanuric acid (C3H3N3S3) have been investigated in polycrystalline sample at room temperature by Fourier Transform Infrared (FT-IR) and FT-Raman spectroscopies in the region 4000-450 cm-1 and 4000-50 cm-1 respectively, which provide a wealth of structural information about the molecules. The spectra are interpreted with the aid of normal co-ordinate analysis following full structure optimization and force field calculations based on density functional theory   (DFT) using standard B3LYP / 6-311++ G (d, p) basis set for investigating the structural and spectroscopic properties. The vibrational frequencies are calculated and the scaled values are compared with experimental FT-IR and FT-Raman spectra. The scaled theoretical wave numbers shows very good agreement with experimental ones. The complete vibrational assignments are performed on the basis of potential energy distribution (PED) of vibrational modes, calculated with scaled quantum (SQM) method. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that change in electron density (ED) in σ* and π* anti-bonding orbitals and second order delocalization   energy (E2) confirm the occurrence of Intra molecular Charge Transfer (ICT) within the molecule. The thermodynamic properties like heat capacity, entropy, enthalpy and zero point energy have been calculated for the molecule. The frontier molecular orbitals have been visualized and the HOMO-LUMO energy gap has been calculated. The Molecular Electrostatic Potential (MEP) analysis reveals the sites for electrophilic attack and nucleophilic reactions in the molecule.

scholarly journals Crystal Structure and Computational Study on Methyl-3-Aminothiophene-2-Carboxylate

Crystals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 19 ◽  
Author(s):  
Yaping Tao ◽  
Ligang Han ◽  
Andong Sun ◽  
Kexi Sun ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Crystal Packing ◽  
Computational Study ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Dispersion Energy ◽  
Monoclinic Crystal ◽  
Hydrogen Bond Interactions ◽  
Calculation Results ◽  
Reduced Density Gradient ◽  
Reduced Density

Methyl-3-aminothiophene-2-carboxylate (matc) is a key intermediate in organic synthesis, medicine, dyes, and pesticides. Single crystal X-ray diffraction analysis reveals that matc crystallizes in the monoclinic crystal system P21/c space group. Three matc molecules in the symmetric unit are crystallographically different and further linked through the N–H⋯O and N–H⋯N hydrogen bond interactions along with weak C–H⋯S and C–H⋯Cg interactions, which is verified by the three-dimensional Hirshfeld surface, two-dimensional fingerprint plot, and reduced density gradient (RDG) analysis. The interaction energies within crystal packing are visualized through dispersion, electrostatic, and total energies using three-dimensional energy-framework analyses. The dispersion energy dominates in crystal packing. To better understand the properties of matc, electrostatic potential (ESP) and frontier molecular orbitals (FMO) were also calculated and discussed. Experimental and calculation results suggested that amino and carboxyl groups can participate in various inter- and intra-interactions.

Synthesis of PMMA-b-PS Block Copolymer by Emulsion ATRP and its Self-Assembly Property

2013 ◽  
Vol 705 ◽  
pp. 115-119
Author(s):  
Bao Yong Tian ◽  
Er Jun Tang ◽  
Miao Yuan ◽  
Rui Xia Hao ◽  
Cun Man Li ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Block Copolymer ◽  
Self Assembly ◽  
Potential Application ◽  
Morphological Characteristic ◽  
Living Polymerization ◽  
The Self ◽  
Emulsion System ◽  
Copolymer Concentration ◽  
Ft Ir

The well-defined block copolymer PMMA-b-PS was prepared by two-step ATRP in emulsion system. GPC results indicate that Mn increased linearly with conversion and polydispersity remained relatively narrow. It presents the characteristics of living polymerization in emulsion system. FT-IR demonstrated that block copolymer PMMA-b-PS could be successfully synthesized by ATRP with macroinitiator PMMA-Cl in emulsion system. The morphological characteristic of the self-assembly depends on the block copolymer concentration and transforms between spheres and rodlike micelles. The property indicates a perfect potential application in drug delivery materials.

scholarly journals Synthesis, Characterization, and Antimicrobial Activity of Methyl-2-aminopyridine-4-carboxylate Derivatives

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
S. Nagashree ◽  
P. Mallu ◽  
L. Mallesha ◽  
S. Bindya
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Studies ◽  
H Nmr ◽  
Chemical Structures ◽  
Elemental Analyses ◽  
Ft Ir

A series of methyl-2-aminopyridine-4-carboxylate derivatives,3a–f,were synthesized in order to determine theirin vitroantimicrobial activity. The chemical structures of the synthesized compounds were confirmed by elemental analyses, FT-IR, and1H NMR spectral studies. Among the synthesized compounds,3cand3dshowed good antimicrobial activity compared to other compounds in the series.

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