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A magnesium complex using N-phthaloyl-β-alanine (NPA) as ligand was synthesized and its crystal structure was characterized by single-crystal X-ray diffraction analysis. The Fourier transformation infrared spectroscopy (FTIR), thermogravimetry (TG) and differential thermal analysis (DTA), fluorescence spectroscopy and terahertz time-domain spectroscopy (THz-TDS) were performed for magnesium N-phthaloyl-β-alaninate (MgNPA). The coordination geometry around Mg (II) has found to be distorted octahedral and the coordination mode of NPA in MgNPA is monodentate i.e. η 1 μ 1 . The significant enhancement was observed in the emission intensity of MgNPA complex as compared to the ligand NPA during solid state photoluminescence spectroscopy. The computational investigations of the complex were carried out at B3LYP/6-31 + G (d,p) level in gas phase to support our experimental results. The small energy gap between frontier molecular orbitals (FMOs) manifested that MgNPA is a very reactive, chemically soft and optically active complex. The terahertz time domain spectroscopy of the complex and ligand was performed in order to characterize as well as to find out refractive index and absorption coefficient in 0.2–3.2 THz frequency range. Both the complex and ligand shows the characteristic absorption peaks in this frequency range. The decrease in refractive index is observed by the complexation of NPA with Mg. [ABSTRACT FROM AUTHOR]

An efficient and facile microwave-assisted solution phase parallel synthesis for a 38-member library of N- aroyl- N ′-aryl thioureas was accomplished successfully. These analogues ( 1 – 38 ) were synthesized under identical set of conditions. It has been observed that the reaction time was drastically reduced from 8 to 12 h for conventional methods to only 10–15 mins. Products obtained were more than 98% pure, as characterized by elemental analysis along with FT-IR and 1 H, 13 C NMR. The solid-phase structural analysis was accomplished by single crystal XRD analysis. The urease inhibitory potential of synthetic compounds was tested and compounds were found to inhibit urease in moderate to significant manner. Compound 17 was the most potent inhibitor of urease having an IC 50 value of 0.17 ± 0.1 μM. To check the cytotoxic profile of the derivatives, lungs cancer cell lines were used. Cytotoxicity analysis revealed remarkable toxicity of the compounds against tested lungs carcinoma and compounds showed variation in inhibition activity due to the substituents attached. The molecular docking studies were carried out to identify the possible binding modes of potent inhibitors in the active site of enzyme. The results suggested that the compounds can be further investigated and used against different cancers. [ABSTRACT FROM AUTHOR]

The new cocrystal adducts of N-phthaloyl-β-alanine and benzimidazole (1:2) with molecular formula C 18 H 15 N 3 O 4 (1) was synthesized by slow evaporation process of the aqueous solution containing the two said moieties. The confirmation of proposed formula can be established through crystal structure as well as FTIR analysis. The crystal structure was confirmed by single X–ray crystal analysis. The experimental and theoretical studies of photophysical properties like Fourier Transform Infrared (FTIR) and ultraviolet–visible spectroscopy (UV–Vis) have been done. The cocrystal belong to monoclinic crystallographic system with space group P21/c, Z = 4. DPPH radical scavenging activity of the title cocrystal is slightly lower than coformer with lower IC 50 value, respectively. One dimensional infinite chain in direction of [010] parallel to b direction. Optimized crystalline network structure of 1 shows that conventional N−H⋯O, and O H⋯N, and the non−conventional C H⋯O hydrogen bonds (HBs) gathered the monomeric components of 1 (1−mon). The reliable calculations of the dispersion corrected density functional theory (DFT−D) display that N−H⋯O and O−H⋯N HBs more share in the stabilization of the network structure. The theoretical study of UV–Vis spectra in solvents (water, acetonitrile, methanol, and n–heptanes) confirms the experimental results as seven main bands in 180–270 nm range. They could attribute to intra-ligand charge transfer (ILCT) as benzimidazole → benzimidazole and N-phthaloyl-β-alanine → N-phthaloyl-β-alanine with π → π* character. Image 103013 • Synthesis a novel cocrystal adducts of N-phthaloyl-β-alanine and benzimidazole (1:2). • Structural characterization by single X–ray crystal, FTIR, and UV–Vis. • Having higher DPPH radical scavenging activity than coformers with lower IC 50 value. • Theoretical study of the constructive non–covalent interactions by DFT–D calculations. • The network stabilized by N−H⋯O, O−H⋯N, and C−H⋯O contacts. [ABSTRACT FROM AUTHOR]

Abstract Theoretical modeling of the geometries of metal-organic frameworks is quite challenging. In order to compare the geometry obtained through density functional theory (DFT) calculations with the one obtained experimentally, a hydrothermal reaction of the potassium salt of 1,1-cyclopentane diacetic acid (L) with MnCl 2 ·2H 2 O in the presence of 4,4′-bipyridine (bpy) was carried out which formulated a two dimensional metal-organic framework [Mn 2 (L) 2 (bpy) 2 (H 2 O) 2 ] n ∙6H 2 O. Single crystal X-ray diffraction analysis reveals that the compound crystallized in the centrosymmetric monoclinic space group P 2/n. The presence of solvate water molecules of crystallization offer hydrogen bond formation and result the connection of 2-D sheets into 3-D hydrogen bonded metal-organic framework. The manganese atom can have a maximum of sextet spin state (five unpaired electrons). Single point energies were calculated at M05-2X/6-31G (d,p) for different spin states (up to 11 et) of the high energy framework and it was elucidated that the 11et spin stat is the lowest energy spin state. [ABSTRACT FROM AUTHOR]

The present research work was aimed to synthesize biologically active Schiff base compound, 2-{(E)-[(3-{[(Z)-(2-hydroxyphenyl)methylidene]amino}-1H-1,2,4-triazol-5-yl)imino]methyl}phenol (L) by condensation reaction of 2-hydroxybenzaldehyde with 3,5-diamino-1,2,4-triazole. In order to evaluate the effect of metal ions on the biological properties, ligand (L) was then coordinated to the metal ions such as Fe(II), Co(II), Cu(II), Ni(II) and Zn(II). Characterization of ligand and its metal complexes was done by physical, spectral and analytical data. The synthesized compounds were screened for antioxidant, enzyme inhibition and antibacterial/antifungal activities. The screening results indicated the ligand to possess bioactivity which significantly enhanced upon chelation/coordination with the metal ions. Computational studies were also carried out on the ligand to check orbital involvement and bonding interactions. The optimized frequency, intensity and geometry of the vibrational bands of ligand (L) were obtained through density functional theory (DFT) using 6–311++G (d.p) basis sets. Molecular stability and bond strength were also studied by carrying out the natural bond orbital analysis (NBO). The calculated HOMO and LUMO energies confirmed the charge transfer in the molecule of ligand. [ABSTRACT FROM AUTHOR]

The isatin-core in compounds offers exciting perspectives in medicinal and pharmacological research. The present study reports the successful development of new isatin-core transition metal based anti-bacterial complexes via conventional refluxing method. The bidentate nature of as-synthesized isatin-core ligand was confirmed using various analytical techniques such as FTIR, 1 H NMR, 13 C NMR, EIMS, and single crystal X-ray diffraction. The computed analysis i.e. IR, UV–Visible, NBO (Natural Bond Orbital) and FMO (Frontier Molecular Orbital) of crystalline isatin-core ligand reflect its dimer nature and predict the conjugative interaction among molecules. Moreover, metal complexes of isatin-core ligand using metallic salts of first transition series i.e. VO(IV), Cr(III), Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) were prepared and further screened against bacterial strains. Octahedral geometry was proposed for all the complexes except vanadium which had square-pyramidal geometry. All the as-prepared metal complexes are found potentially active entities against both of the gram-positive and gram-negative bacterial strains. Additionally, the bacterial screened data revealed that metal complexes have better bactericidal activities compared to their parent ligand. [ABSTRACT FROM AUTHOR]

In the present work a novel cocrystal adduct of N –phthaloyl–β–alanine and 2,2–bipyridyl as compound 1 with molecular formula C 16 H 13 N 3 O 4 was synthesized by slow evaporation process of the ethanoic solution containing these two moieties. In followings, the crystal structure and photophysical properties of 1 was characterized by single X-ray crystal analysis, FTIR, and UV–Vis spectra. The thermal behavior was analyzed by the Thermogravimetric/Differential Thermal Analyzer (TG-DTA). The cocrystal belong to monoclinic crystallographic system with space group P 21/ n , Z = 4. DPPH radical scavenging activity of the title cocrystal is slightly higher than coformer with lower IC 50 value. Finally, using DFT calculations executed at hybrid B3LYP/6–311+G ( d , p ) level of theory the geometric and electronic structures of the crystalline network of C 16 H 13 N 3 O 4 ( 1 ), studied. Inter-molecular conventional O H⋯N as well as the non-conventional C H⋯O hydrogen bonds (HBs) and C H···π and C O···π stacking interactions gathered the monomeric structures of 1 ( 1-mon ) to create the 3D architecture of the network ( 1-net ). The dispersion corrected density functional theory (DFT-D) calculations indicate that O H⋯N and C H⋯O HBs, govern the 1-net formation. The calculated UV–Vis spectrum in vacuo has agreement with the experimental one that shows five major bands in the range of 170–271 nm that could assigned to transitions between 2,2-bipyridyl and N -phthaloyl-β-alanine parts of 1 with n → π ∗ and π → π* ligand-ligand-charge transfer (LLCT) character. The calculated electronic spectra in solvents (water, acetonitrile, methanol, and n–heptane) comparing with the vacuo one show broad bands with blue shifts. [ABSTRACT FROM AUTHOR]

A solvo-thermal method is employed to synthesize SnO 2 nanorods and the Fourier transformed infrared spectroscopic analysis confirms the formation of Sn O bond. The X-ray diffraction analysis suggests that SnO 2 nanorods exist in tetragonal rutile crystal structure phase. Transmission electron microscopy images show the formation of nanorods with an average diameter ∼10–15 nm and length 35–50 nm. The deconvoluted photoluminescence spectrum suggests the existence of three distinct origins of photoluminescence, which peaks at photon energies of ∼423 nm (2.93 eV), ∼470 nm (2.64 eV) and 480 nm (2.58 eV). The measured photoluminescence kinetics is best described by a tri-exponential decay model suggesting that the photoluminescence occurs from three distinct channels with time constants 1.31 ns, 4.89 ns and 13.24 ns. These studies suggest that SnO 2 nanorods synthesized by solvo-thermal method at mild conditions can be used for luminescent device applications. The long lived emission of SnO 2 nanorods in the visible region make them suitable candidate as an active materials for many opto-electronic devices such as light emitting diodes and solar cells. [ABSTRACT FROM AUTHOR]

The presented work studies the geometric and electronic structures of the crystalline network of a novel amide based carboxylic acid derivative, N–[(4–chlorophenyl)]–4–oxo–4–[oxy] butane amide, C 10 H 10 NO 3 Cl ( 1 ), constructed via hydrogen bonds (HBs) and stacking non–covalent interactions. Compound 1 was synthesized and characterized by FTIR, 1 H, and 13 C NMR, and UV–Vis spectra, X–ray structural, DTA–TG, and EI–MS, analyses. DFT calculations about molecular and related network of 1 were performed at hybrid B3LYP/6–311+G ( d , p ) level of theory to support the experimental data. The neutral monomeric structures join together via inter−molecular conventional O/N H⋯O and non−conventional C H⋯O HBs and O H···π and C O···π stacking interactions to create 2−D architecture of the network. The results of dispersion corrected density functional theory (DFT−D) calculations within the binding energy of the constructive non−covalent interactions demonstrate that HBs, especially conventional O H⋯O and N H⋯O, govern the network formation. The calculated electronic spectrum show six major bands in the range of 180–270 nm which confirm the experimental one within an intense band around 250 nm. These charge transfer bands result from shift of lone pair electron density of phenyl to chlorine or hydroxyl or phenyl functional groups that possess π → π* and π → n characters. [ABSTRACT FROM AUTHOR]

The title molecule, 3-( N -phthalimidomethyl)-4-amino-1,2,4-triazole-5-thione (C 11 H 9 N 5 O 2 S), was synthesized by the fusion of N -Phthaloylglycine and thiocarbohydrazide at 145 °C. In this study, we have investigated the crystal structure, photophysical properties as well as the relation between the molecular structure and nonlinear optical properties of 2-(4-Amino-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-ylmethyl)isoindoline-1,3-dione. For this purpose, the molecular structure, vibration spectrum, electronic absorption spectrum, 1 H and 13 C NMR spectra have been evaluated by both of the experimental techniques and density functional theory method. A detailed assignment of vibrational bands has been performed on the basis of potential energy distribution analysis. Additionally, UV–Vis spectrum was recorded in different solvents in order to examine the solvent effect on the electronic absorption spectrum. NBO analysis has been carried out to investigate intra-molecular charge transfer interactions. Finally, nonlinear optical properties of the title compound have been investigated by using M062X level of density functional theory. [ABSTRACT FROM AUTHOR]

A calcium complex of N-phthaloylglycine (CaNPG) has been synthesized, and its crystal structure has been characterized by X-ray diffraction method. The FT-IR and fluorescence spectra for CaNPG have been recorded. N-phthaloylglycine ligand coordinates to Ca ion through the carboxylate O atoms as a bidentate ligand, and Ca ion does not play an important role in florescence spectrum. In order to support experimental findings and also investigate molecular surfaces, natural bond orbital (NBO) and nonlinear optical (NLO) optical properties of CaNPG complex, density functional theory calculations have been performed by hybrid B3LYP level. The very small energy gap between α-spin frontier molecular orbitals (FMOs) is demonstrated that CaNPG is a very reactive, chemically soft and optically active complex. The high stabilization energies of hyperconjugative interactions are also demonstrate that the charge mobility in CaNPG is very high. As consistent with above findings, first static hyperpolarizability of CaNPG has been found to be 10 times higher than pNA which is a NLO material. [ABSTRACT FROM AUTHOR]

• Synthesis of mono- and bis-Schiff base ligands of 3,5-diamino-1,2,4-triazole along with their transition metals complexes. • Experimental (IR, UV-Vis, 1HNMR, 13CNMR, ESI-MS) and computational characterization at B3LYP/6-311G(d.p) was done. • Thermal stability and fluorescence properties of compounds were evaluated. • In vitro evaluation of the synthesized ligands and their corresponding 3 d -metal complexes against five pathogenic bacterial species. • Enzyme inhibitory evolution of compounds against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The aim of this project was to introduce novel bioactive compounds through the design and synthesis of two mono-Schiff bases, 4- [(5-amino-1H-1,2,4-triazol-3-yl)imino]methylbenzene-1,3-diol (L1) and 2- [(5-amino-1H-1,2,4-triazol-3-yl)imino]methyl}-6-methoxyphenol (L2) and one bis-Schiff base, 2,2′-{1H-1,2,4-triazole-3,5-diylbis [nitrilomethylylidene]}bis(6-methoxyphenol) (L3) together with their complexes of transition metals [VO(IV), Cr(III), Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II)]. The molecular structures of as-synthesized Schiff bases were explicitly confirmed by physical, spectral, analytical and computational studies. Quantum chemical calculations based on density functional theory (DFT) were performed at B3LYP/6-311+G(d.p) level to explore the optimized geometrical structures, molecular electrostatic potential (MEP), Mulliken atomic charges (MAC) and frontier molecular orbital (FMO) analysis of the as-synthesized ligands. The FMO energy gaps were rationalized to be 0.162, 0.158 and 0.138 eV for ligands (L1), (L2) and (L3) , respectively which can efficiently polarize their chemical structures. As-synthesized metal complexes have good agreement with their purposed structures with octahedral geometry except vanadium complexes, which have square pyramidal geometry. As-synthesized compounds were also evaluated through thermogravimetry and fluorescence analysis. Additionally, the compounds were also scrutinized for antibacterial activity against five bacterial strains (Halomonas halophila, Chromohalobacter israelensis, Escherichia coli, Chromohalobacter salexigens and Halomonas salina) and enzyme inhibition bioassay against butyrylcholinesterase (BChE) and acetylcholinesterase (AChE). The results showed that the complexes (15) and (1) were the most active inhibitors of BChE and AChE enzymes with 94.60% and 90.90% activity, respectively. Moreover, all the compounds also exhibited significant antibacterial activity. It has been found that the metal complexes displayed more biological activity in contrary to parent ligands as a result of chelation. [Display omitted] [ABSTRACT FROM AUTHOR]