Showing papers by "Saied M. Soliman published in 2016"

Ultrasonic Synthesis, Molecular Structure and Mechanistic Study of 1,3-Dipolar Cycloaddition Reaction of 1-Alkynylpyridinium-3-olate and Acetylene Derivatives.

Abstract: Regioselectively, ethyl propiolate reacted with 1-(propergyl)-pyridinium-3-olate to give two regioisomers; ethyl 4-oxo-8-(prop-2-ynyl)-8-aza-bicyclo(3.2.1)octa-2,6-diene-6-carboxylate 4, ethyl 2-oxo-8-(prop-2-ynyl)-8-aza-bicyclo(3.2.1)octa-3,6-diene-6-carboxylate 5 as well as ethyl 2,6-dihydro-6-(prop-2-ynyl)furo(2,3-c)pyridine-3-carboxylate 6. The obtained compounds were identified by their spectral (IR, mass and NMR) data. Moreover, DFT quantum chemical calculations were used to study the mechanism of the cycloaddition reaction. The regioselectivity was explained using transition state calculations, where the calculations agreed with the formation of products 4 and 5 in almost the same ratio. The reaction was also extended for diphenylaceylene as dipolarophile to give only two products instead of three.

Synthesis, Spectroscopic, X-ray Diffraction and DFT Studies of Novel Benzimidazole Fused-1,4-Oxazepines.

Abstract: A series of benzimidazole-tethered oxazepine heterocyclic hybrids has been synthesized in good to excellent yields from an N-alkylated benzimidazole 2-carboxaldehyde, which in turn was accomplished from o-phenylenediamine in three good yielding steps. The calculated molecular structure of compounds 2-methyl-4-(2-((phenylimino)methyl)-1H-benzo-[d]imidazol-1-yl)-butan-2-ol 9 and 10 3,3-dimethyl-N-phenyl-1,2,3,5-tetrahydrobenzo-[4,5]imidazo[2,1-c][1,4]oxazepin-5-amine using the B3LYP/6-31 G(d, p) method were found to agree well with their X-ray structures. The charge distributions at the different atomic sites were computed using the natural bond orbital (NBO) method. The regions of electrophilic and nucleophilic reactivity were shown using a molecular electrostatic potential (MEP) map. In addition, the frontier molecular orbitals of these compounds were discussed at the same level of theory. Nonlinear optical (NLO) properties have also been investigated by computational hyperpolarizability studies, and it was found that Compound 9 is the best candidate for NLO applications.

Decomposition of Intermolecular Interactions in the Crystal Structure of Some Diacetyl Platinum(II) Complexes: Combined Hirshfeld, AIM, and NBO Analyses.

Abstract: Intermolecular interactions play a vital role in crystal structures. Therefore, we conducted a topological study, using Hirshfeld surfaces and atom in molecules (AIM) analysis, to decompose and analyze, respectively, the different intermolecular interactions in six hydrazone-diacetyl platinum(II) complexes. Using AIM and natural bond orbital (NBO) analyses, we determined the type, nature, and strength of the interactions. All the studied complexes contain C-H⋯O interactions, and the presence of bond critical points along the intermolecular paths underlines their significance. The electron densities (ρ(r)) at the bond critical points (0.0031–0.0156 e/a03) fall within the typical range for H-bonding interactions. Also, the positive values of the Laplacian of the electron density (∇2ρ(r)) revealed the depletion of electronic charge on the interatomic path, another characteristic feature of closed-shell interactions. The ratios of the absolute potential energy density to the kinetic energy density (|V(r)|/G(r)) and ρ(r) are highest for the O2⋯H15-N3 interaction in [Pt(COMe)2(2-pyCMe=NNH2)] (1); hence, this interaction has the highest covalent character of all the O⋯H intermolecular interactions. Interestingly, in [Pt(COMe)2(H2NN=CMe-CMe=NNH2)] (3), there are significant N-H⋯Pt interactions. Using the NBO method, the second-order interaction energies, E(2), of these interactions range from 3.894 to 4.061 kJ/mol. Furthermore, the hybrid Pt orbitals involved in these interactions are comprised of dxy, dxz, and s atomic orbitals.

Synthesis, Molecular Structure Optimization, and Cytotoxicity Assay of a Novel 2-Acetyl-3-amino-5-[(2-oxopropyl)sulfanyl]-4-cyanothiophene

Abstract: A novel thiophene-containing compound, 2-acetyl-3-amino-5-[(2-oxopropyl)sulfanyl]-4-cyanothiophene (4) was synthesized by reaction of malononitrile with CS₂ in the presence of K₂CO₃ under reflux in DMF and the subsequent reaction with chloroacetone followed by cyclization. This compound has been characterized by means of FT-IR, ¹H-NMR, (13)C-NMR, and mass spectrometry as well as elemental analysis. In addition, the molecular structures of compound 4 was determined by X-ray crystallography. The geometry of the molecule is stabilized by an intramolecular interaction between N1-H1···O1 to form S6 graf set ring motif. In the crystal, molecules are linked via N1-H2···O1 and C7-H7A···N2 interactions to form a three-dimensional network. Molecular structure and other spectroscopic properties of compound 4 were calculated using DFT B3LYP/6-31G (d,p) method. Results revealed a good agreement between the optimized geometric parameters and the observed X-ray structure. Furthermore, and by employing the natural bond orbital (NBO) method, the intramolecular charge transfer (ICT) interactions along with natural atomic charges at different sites, were calculated; results indicated strong n→π* ICT from LP(1)N5→BD*(2)C15-C16 (63.23 kcal/mol). In addition, the stabilization energy E(2) of the LP(2)O3→ BD*(1)N5-H6 ICT (6.63 kcal/mol) indicated the presence of intramolecular N-H···OH bonding. Similarly, calculations of the electronic spectra of compound 4 using, TD-DFT revealed a good agreement with the experimental data. Finally, compound 4 was evaluated for its in vitro cytotoxic effect against PC-3 and HeLa cell lines, as an anticancer agent, and found to be nontoxic.

Theoretical Study on Regioselectivity of the Diels-Alder Reaction between 1,8-Dichloroanthracene and Acrolein

Abstract: A theoretical study of the regioselectivity of the Diels-Alder reaction between 1,8-dichloroanthracene and acrolein is performed using DFT at the B3LYP/6-31G(d,p) level of theory. The FMO analysis, global and local reactivity indices confirmed the reported experimental results. Potential energy surface analysis showed that the cycloadditions (CAs) favor the formation of the anti product. These results are in good agreement with the reported results obtained experimentally where the anti is the major product.

Topology analysis reveals supramolecular organisation of 96 large complex ions into one geometrical object

Abstract: It is shown that the highly complex crystal structure of [Ag(4-(pyrrolidin-1-yl)pyridine)2]NO3·1/2H2O, 1, with 12 symmetry-independent Ag+ ions and 96 units of complex ions in a unit cell can be understood by the ubiquitous srs topology, reducing thousands of atom positions into a single geometrical object in one go.

Synthesis of Novel 5‐Monoalkylbarbiturate Derivatives: New Access to 1,2‐Oxazepines.

Abstract: A simple and straightforward route to 5-monoalkylbarbiturates by the NHEt2 catalyzed Michael reaction of 1,3-dimethylbarbituric acid and α,β-unsaturated ketones is described. Significantly, the reaction exclusively furnished 5-monoalkylbarbiturates. Under neat conditions, the mixing and grinding of a representative 1,5-diketone and hydroxylamine hydrochloride gave the corresponding 1,2-oxazepine in very good yield.

Molecular Structure, Spectroscopic and DFT Computational Studies of Arylidene-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione

Abstract: Reaction of barbituric acid derivatives and di-substituted benzaldehyde in water afforded arylidene-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione derivatives (1 and 2). The one step reaction proceeded efficiently, smoothly, and in excellent yield. The arylidene compounds were characterized by spectrophotometric tools plus X-ray single crystal diffraction technique. Quantum chemical calculations were performed using the DFT/B3LYP method to optimize the structure of the two isomers (1 and 2) in the gas phase. The optimized structures were found to agree well with the experimental X-ray structure data. The highest occupied (HOMO) and lowest unoccupied (LUMO) frontier molecular orbitals analyses were performed and the atomic charges were calculated using natural populationanalysis.

Crystal structure of 2-(bis(methylthio)methylene)1-phenylbutane-1,3-dione, C13H14O2S2

Abstract: Abstract C13H14O2S2, triclinic, P1̅ (no. 2) a = 8.0970(9) Å, b = 8.8152(10) Å, c = 9.8217(10) Å, α = 76.269(5)°, β = 69.539(4)°, γ = 82.065(5)°, ϛ = 636.87(12) Å3, Z = 2, Rgt(F) = 0.028, wRref(F2) = 0.073, T = 100 K.

Crystal structure of 6-hydroxy-5-((2-hydroxy-6-oxocyclohex-1-en-1-yl)(4-methoxyphenyl)methyl)-1,3-dimethylpyrimidine-2,4(1H,3H)-dione, C20H22N2O6

Abstract: Abstract C20H22N2O6, monoclinic, P21/c (no. 14), a = 8.6657(6) Å, b = 18.6201(14) Å, c = 22.3583(18) Å, β = 91.808(3)°, V = 3605.9(5) Å3, Z = 8, Rgt(F) = 0.067, wRref(F2) = 0.177, T = 100(2) K.

Crystal structure of (E)-2-(bis(methylthio)methylene)-1-phenyl-3-(2-phenylhydrazono)butan-1-one, C19H20N2OS2

Abstract: Abstract C19H20N2OS2, monoclinic, P21/c (no. 14), a = 10.6164(9) Å, b = 8.4131(6) Å, c = 20.2448(16) Å, β = 100.021(4)°, V = 1780.6(2) Å3, Z = 4, Rgt(F) = 0.040, wR(F2) = 0.081, T = 100 K.