Optimization,Spectroscopic(FT-IR,Excited States,UV/Vis) Studies,FMO, ELF,LOL, QTAIM and NBO Analyses and Electronic Properties of Two New Pyrimidine Derivatives

In the given research, the molecular structures of two new compounds, 4-((E)-3-(dimethylamino)styryl)-6-((E)-4-(dimethylamino)styryl)pyrimidine-2-amine(PM-1) and N-(4-((E)-3-(dimethylamino)styryl)-6-((E)-4-(dimethylamino)styryl)pyrimidine-2-yl)-4,6-dichloro 1,3,5-1,3,5-triazin-2-amine(PM-2), have been studied with the use of density functional theory(DFT/B3 LYP/MidiX) in dimethylformamide(DMF) for the first time. The electronic spectra of the new compounds in a DMF solvent were carried out by temporally dependent density functional theory(TD-DFT) method. The computed absorption spectral data of the title compounds are in good agreement with the experimental data, thus allowing an assignment of the UV/Vis spectra. The equilibrium geometry, the HOMO and LUMO molecular orbitals, excitation energies, oscillator strengths and Natural Bond Orbital(NBO) analysis for the molecules have also been calculated and presented. FT-IR spectra of the title molecules are recorded and discussed. The electron location function(ELF), localized orbital locator(LOL) and quantum theory of atoms in molecules(QTAIM) analyses were also carried out. On the basis of polyvinyl alcohol(PVA) and synthesized molecules, polarizer for UV/Vis region of the spectrum has been developed.     

Synthesis and Antimicrobial Activity of Methyl (2 Z )-4-Aryl-2-{4-[(4,6-dimethylpyrimidin-2-yl)sulfamoyl]phenylamino}-4-oxobut-2-enoates and Their Silver Salts

A series of new methyl (2Z)-4-aryl-2-{4-[(4,6-dimethylpyrimidin-2-yl)-sulfamoyl]phenylamino}-4-oxobut-2-enoates was synthesized by the reaction of methyl esters of aroylpyruvic acids with 2-(4-aminobenzenesulfamido)-4,6-dimethylpyrimidine in a mixture of acetic acid–ethanol (1 : 1). The obtained 4-oxobut-2-enoates reacted with silver nitrate in ethanol–DMF (2 : 1) to form their silver salts. The antimicrobial activity of the compounds was studied.     

Diorganyl ditellurides with intramolecular coordination bonds: synthesis and structure of bis(4,6-dimethylpyrimidin-2-yl) ditelluride

A reaction of 2-chloro-4,6-dimethylpyrimidine with sodium ditelluride in DMF afforded bis(4,6-dimethylpyrimidin-2-yl) ditelluride, a new representative of dihetaryl ditellurides. An X-ray diffraction study revealed an unusual planar trans-conformation of this compound, which is stabilized by both intramolecular attractive non-valent Te...N interactions (3.082(2) Å) and π-stacking of the aromatic heterocycles (the centers of the pyrimidine rings are disposed at 3.421(3) ). The energy parameters of the factors that make the molecular structure flattened were estimated by quantum chemical DFT calculations.     

Synthesis,characterization, crystal structure and DFT studies on 3-(1H-benzo[d][1,2,3]triazol-1-yl)-1-(4-ethylphenyl)-1-oxopropan-2-yl-4-ethylbenzoate

3-(1H-benzo[d][1,2,3]triazol-1-yl)-1-(4-ethylphenyl)-1-oxopropan-2-yl-4-ethyl-benzoate (BEOE) has been synthesized and characterized by elemental analysis, IR, UV–vis and fluorescence spectroscopy. Its crystal structure has also been determined by X-ray single crystal diffraction. For the title compound, density functional theory (DFT) calculations of the structure and vibrational frequencies have been performed at B3LYP/6-31G* level of theory. Based on the vibration analysis, thermodynamic properties of the title compound have been calculated. The correlative equations between the thermodynamic properties and temperatures have also been listed. By using TD-DFT method, electron spectra of the title compound have been predicted, which suggests the B3LYP/6-31G* method can approximately simulate the electron spectra for the system presented here.     

Synthesis and Biological Activity of Compounds Obtained by Reacting Methyl Aroylpyruvates with Sulfadimidine

The reaction of methyl aroylpyruvates and 2-(4-aminobenzenesulfamido)-4,6-dimethylpyrimidine in glacial acetic acid in the presence of anhydrous sodium acetate afforded (2Z)-4-aryl-2-hydroxy-N-{4-[(4,6-dimethylpyrimidin-2-yl)sulfamoyl]phenyl}-4-oxobut-2-enamides. Reaction of the above reagents in a mixture of acetic acid and ethanol (1: 1) in the absence of anhydrous sodium acetate gave methyl (2Z)-4-aryl-2-{4-[(4,6-dimethylpyrimidin-2-yl)sulfamoyl]phenylamino}-4-oxobut-2-enoates. Analgesic and anti-inflammatory activities of the synthesized compounds was studied.     

Experimental, theoretical and biological activity study on 1-(4,5-dihydro-3-arylpyrazol-1-yl)-2-(1H-1,2,4-triazol-1-yl)-ethanone

Four compounds have been synthesized and characterized by¹H NMR spectroscopy and elemental analyses, among which 1-(4,5-dihydro-3-phenyl-pyrazol-1-yl)-2-(1H-1,2,4-triazol-1-yl)ethanone 3a was further confirmed by X-ray crystallographic analysis. The biological activities of these compounds were tested, with the result that they displayed moderate fungicidal activities. In addition, a MO calculations using density functional theory (DFT) at B3LYP/6-31G^* level have also been carried out, and the structure–activity relationships for these compounds are discussed.     

Synthesis and study of N,N′-disubstituted derivatives of pyromellitic diimide

Russian Chemical Bulletin - New N, N′-bis(4,6-dimethylpyrimidin-2-yl)- and N, N′-bis(2,3,5,6-tetrafluorophenyl)-substituted pyromellitic diimides were synthesized. Their properties were...     

Molecular structure, vibrational spectra and NBO analysis of phenylisothiocyanate by density functional method

The molecular geometry, vibrational frequencies and NBO analysis of phenylisothiocyanate (PITC) in the ground state have been calculated by using density functional theory calculation (B3LYP) with 6-311++G(d,p) basis set. The optimized geometrical parameters obtained by DFT calculations are in good agreement with experimental values. Comparison of the observed fundamental vibrational frequencies of the PITC and calculated result by density functional theory (B3LYP) indicates B3LYP is superior for molecular vibrational problems. The entropy of the title compound was also performed at HF/B3LYP/6-311++G(d,p) levels of theory. Natural bond orbital (NBO) analysis of title molecule is also carried out. A detailed interpretation of the IR and Raman spectra of PITC is reported on the basis of the calculated potential energy distribution (PED). The theoretical spectrogram for IR spectrum of the title molecule has been constructed.     

FT-IR, FT-Raman and UV spectral investigation; computed frequency estimation analysis and electronic structure calculations on 1-nitronaphthalene

In this work, the vibrational spectral analysis was carried out by using FT-Raman and FT-IR spectroscopy in the range 100-4000cm(-1) and 400-4000cm(-1) respectively, for 1-nitronaphthalene (C(10)H(7)NO(2)) molecule. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based density functional theory (DFT) and ab initio HF methods and different basis sets combination. The complete vibrational assignments of wavenumbers were made on the basis of total energy distribution (TED). The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement with observed spectra. The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values over the other methods. The energy and oscillator strength calculated by time-dependent density functional theory (TD-DFT) complements with the experimental findings. Thermodynamic properties of the title compound at different temperatures have been calculated. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) were performed.     

Synthesis,antioxidant, antibacterial,and DFT study on a coumarin based salen-type Schiff base and its copper complex

Synthesis of new efficient compounds is becoming urgent due to the resistance of organisms to drugs. Salen derivatives have interesting therapeutic and industrial applications. A coumarin based derivative of salen, 7-hydroxy-8-((E)-((2-((E)-((7-hydroxy-5-methyl-2-oxo-3,8a-dihydro-2Hchromen-8-yl)methylene)amino)-4-methylphenyl)imino)methyl)-5-methyl-2H-chromen-2-one (L), and its copper complex, CuL, have been synthesized and characterized. Antibacterial and antioxidant activity of these compounds have been evaluated and electronic, optical and molecular properties have been calculated using density functional theory (DFT) with B3LYP. The results were correlated with the biological activity and reactivity of the compounds. Experimental and theoretical calculations indicate that the studied copper complex has the potential to function as a drug.     

Synthesis, crystal structure, insecticidal activity and DFT study on the geometry and vibration of O-(E)-1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethyleneamino-O-ethyl-O-phenylphosphorothioate

The title compound, O-(E)-1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethyleneamino-O-ethyl-O-phenylphosphorothioate, has been synthesized via the condensation reaction of 1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethanone oxime and O-ethyl-O-phenylphosphorochloridothioate in the presence of NaOH powder in refluxing EtOH. Its structure was characterized by (1)H NMR, FTIR, Raman, elemental analysis and X-ray single crystal diffraction. The results of preliminary bioassays indicated that the title compound displays good insecticidal activity. Density functional (DFT) calculations have been carried out for the title compound by using the Becke-Lee-Yang-Parr's three-parameter hybrid functional (B3LYP) method at 6-31G and 6-31G basis sets. The calculated results show that the predicted geometry can well reproduce the structural parameters. The vibrational wave numbers of the title compound were calculated at same level. Predicted vibrational frequencies have been assigned and compared with experimental IR and Raman spectra and they are supported each other.     

Investigations on crystal structure of a novel 3-((4,6-dimethylpyrimidin-2-yl)amino)isobenzofuran-1(3H)-one,and related theoretical studies

In this report, 3-((4,6-dimethylpyrimidin-2-yl)amino)isobenzofuran-1(3H)-one have been synthesized via reaction between phthalaldehydic acid and 2-amino-4,6-dimethylpyrimidine in 90% yields and characterized by Infrared (IR), Nuclear Magnetic Resonance (NMR), Ultraviolet–visible (UV–Vis), X-ray single crystal diffraction techniques. The single-crystal X-ray analysis shows that the title compound crystallizes in the triclinic space group P-1 with unit-cell parameters a = 7.9351(4) Å, b = 11.1687(6) Å, c = 16.1281(9) Å, α = 73.713(5)°, β = 80.362(5)°, γ = 72.882(4)° and Z = 4. A theoretical study with hybrid functional B3LYP 6-311G (d, p) basis set have been used in calculations. The structural and electronic properties have been detailed. The title compound was screened for its antioxidant activity by (1,1-diphenyl-2-picryl hydrazyl) free radical scavenging (DPPH), Ferric ion reducing antioxidant power (FRAP), total phenolic contents (TP) assays and its ferrous ions chelating property. Electronic absorption titration, thermal denaturation measurement and viscosity techniques were used to determine the interaction between double stranded DNA (dsDNA) and compound 1. In three techniques, the mode of binding of compound 1 to dsDNA is minor groove. The UV–Vis measurement results allowed the calculation of the binding constant showing the binding strength of compound 1 to dsDNA was calculated as 8.13 × 10⁴ ± 0.07 L mol⁻¹. Moreover, the molecular docking calculations have been performed to investigate the compound–DNA interactions, computationally. In molecular docking calculations, it was observed that for the title compound, the lowest energy docking pose takes place in the minor groove of DNA and in addition to minor groove binding, interactions between the compound and the consecutive base pairs of DNA which may cause a partial intercalation were also observed. Results showed that title compound – DNA complex is stabilized by several hydrogen bonds, and Pi-alkyl interactions also take part in the stabilization of the complex. Binding affinities of the lowest energy docking pose of the title compound was found to be −8.3 kcal/mol.     

3<Emphasis Type="Italic">H</Emphasis>-Benzo[<Emphasis Type="Italic">a</Emphasis>]imidazo[4,5-<Emphasis Type="Italic">j</Emphasis>]acridine as a new fluorescent heterocyclic system: synthesis,spectral studies,and quantum chemical investigation

The synthesis, spectral studies, and theoretical calculations of a new fluorescent heterocyclic system are described. New 3H-benzo[a]imidazo[4,5-j]acridines were obtained in high yields by the reaction of 1-alkyl-5-nitro-1H-benzimidazoles with (naphthalen-1-yl)acetonitrile via nucleophilic substitution of hydrogen, and their structures were established by spectral (UV-Vis, FT-IR, 1H and 13C NMR) and analytical data. Study of the optical and solvatochromic properties of the dyes revealed their high molar absorption coefficients and high fluorescence quantum yields which in some cases exceeded quantum yields of well-known fluorescent dyes such as fluorescein. Density functional theory (DFT) calculations using the B3LYP hybrid functional and 6-311++G(d,p) basis set were performed to obtain optimized geometries and frontier orbital structures of the synthesized compounds. The electronic absorption spectra were also simulated by the time-dependent density functional theory (TD-DFT) method.     

Synthesis,structural, computational,electronic spectra,wave function properties and molecular docking studies of (Z)-4-(((5-methylfuran-2-yl)methylene)amino)-N-(thiazol-2-yl)benzenesulfonamide

The (Z)-4-(((5-methylfuran-2-yl) methylene)amino)-N -(thiazol-2-yl) benzene sulfonamide (5M2FTH) was synthesized and characterized by the Infrared, UV–Visible, and NMR analysis. Using density functional theory, the current work is a set of theoretical studies on 5M2FTH. The compound molecular structure and geometry were defined using DFT. Topological studies, like ELF, LOL, ALIE, and RDG studies, were done with the Multiwfn-3.8 to find the main binding areas and weak interactions in the molecule. UV spectra was simulated using TD-DFT with implicit solvation model. The HOMO-LUMO, MEP, and NLO properties were carried out in the gas phase. The NBO calculations are used to study how charges move between and within the molecule and stability of this molecule. Pharmacological analysis was performed using Swiss-ADME and found that the compound is a potential drug candidate. PASS analysis revealed that the molecule can show antiparasitic properties which is confirmed by molecular docking against the target protein.     

Synthesis, spectroscopic and DFT investigation of dimethyl-2-(5-acetyl-2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)-3-(triphenylphosphinylidene)succinate

Dimethyl-2-(5-acetyl-2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)-3-(triphenylphosphinylidene)succinate has been synthesized and characterized by elemental analysis, FT-IR and ¹H, ¹³C and ³¹P NMR. The vibrational wavenumbers, gauge including atomic orbital (GIAO) ¹H and ¹³C chemical shift values of title compound in the ground state have been computed with density functional theory method (DFT) and the B3LYP functional. The basis sets used are 6-311G(d,p) and 6-31G(d). The harmonic vibrational wavenumbers have been computed and the scaled values have been compared with the experimental FT-IR spectra. The complete assignments have been performed on basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Most of the computed wavenumbers are found to be in good agreement with the observed spectrum.     

Study of structure and spectral characteristics of the binuclear zinc complex with (<Emphasis Type="Italic">E</Emphasis>)-2-({2-[3-(pyridin-2-yl)-1<Emphasis Type="Italic">H</Emphasis>-1,2,4-triazol-5-yl]phenylimino}methyl)phenol

A study of the structure and spectral properties of the compound (E)-2-({2-[3-(pyridin-2-yl)-1H-1,2,4-triazol-5-yl]phenylimino}methyl)phenol and its binuclear complex with zinc was carried out by the quantum-chemical calculations at a level of density functional theory. Within the framework of the time-dependent density functional theory were calculated electron spectra of both compounds, which gave good agreement with experiment, and was revealed the nature of the absorption bands in the visible and near UV region taking into account the solvent effect. Complete interpretation of the absorption bands in the infrared spectra of the complex and protonated ligand was given, and the frequency shift and changes in the intensities of IR bands of the ligand at the complex formation were analyzed.     

Spectroscopic, quantum chemical DFT/HF study and synthesis of [2.2.1] hept-2'-en-2'-amino-N-azatricyclo [3.2.1.0(2,4)] octane

The compound 4-N-bicyclo [2.2.1] hept-2'-en-2'-amino-N-azatricyclo [3.2.1.0(2,4)] octane (2) has been synthesized and characterized by elemental analysis, IR, UV-vis, mass and NMR. Density functional theory (DFT) and Hartree-Fock (HF) calculations have been carried out for the title compound by using the standard 6-31G* basis set. The calculated results show that the predicted geometry can well reproduce the structural parameters. Predicted vibrational frequencies have been assigned and compared with experimental IR spectra and they complement each other. The theoretical electronic absorption spectra have been calculated by using CIS, TD-DFT and ZINDO methods. The (13)C NMR and (1)H NMR of compound (2) have been calculated by means of Becke 3-Lee-Yang-Parr (B3LYP) density functional method with 6-31G* basis set. Comparison between the experimental and the theoretical results indicates that density functional B3LYP method is able to provide satisfactory results for predicting NMR properties. On the basis of vibrational analyses, the thermodynamic properties of the title compound at different temperatures have been calculated.     

Red shifting of absorption maxima of phenothiazine based dyes by incorporating electron-deficient thiadiazole derivatives as π-spacer

This study was carried out to design phenothiazine based dyes by incorporating electron-deficient thiadiazole derivatives as π-spacer. Density functional theory and time-dependent density functional theory calculations of the geometries, electronic structures and absorption spectra of the dyes before and after binding to titanium oxide were carried out. Effects of the electron-deficient units on the spectra and electrochemical properties have been investigated. Compared with the reference compound CS1A, Dyes 1–4 display remarkably enhanced spectral responses in the red portion of the solar spectrum. The newly designed dyes demonstrate desirable energetic and spectroscopic parameters, and may lead to efficient metal-free organic dye sensitizers for DSSCs.     

Synthesis of derivatives of 2-aminoimidazole and 2-iminoimidazolidine by cyclization of 1-aryl-2-(4,6-dimethylpyrimidin-2-yl)guanidines with α-bromocarbonyl compounds

Cyclization of 1-aryl-2-(4,6-dimethylpyrimidin-2-yl)guanidines with α-bromoacetophenone and ethyl bromoacetate gave derivatives of 1,4-diphenyl-1H-imidazole-2-amine and 2-amino-1-phenylimidazolidin- 4-one respectively. The mechanism of the reaction was determined on the basis of quantum-chemical calculations, NOESY NMR spectroscopy, and X-ray crystallography.     

Theoretical and Experimental Study on 3-Phenyl-5-Phenylazo-3H-[1,3,4] Thiadiazole-2-Thione

3-Phenyl-5-phenylazo-3H-[1,3,4] thiadiazole-2-thione has been synthesized and characterized by X-ray diffraction and FTIR spectra. An extended MO calculation using density functional theory (DFT) at B3LYP/6-31g* level has been carried out. The results of the calculations were compared with experimental data and they are found to support each other. The thermodynamic properties of the title compound at different temperatures also have been calculated on the basis of vibration analyses.