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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]

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 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]

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]