Agata Trzesowska-Kruszynska

Synthesis and characterization of 2-substituted benzimidazoles and their evaluation as anticancer agent.

In this work, we report a series of benzimidazole derivatives synthesized from benzene-1,2-diamine and aryl-aldehydes at room temperature. The synthesized compounds have been characterized on the basis of elemental analysis and various spectroscopic studies viz., IR, (1)H- and (13)C-NMR, ESI-MS as well by X-ray single X-ray crystallographic study. Interaction of these compounds with CT-DNA has been examined with fluorescence experiments and showed significant binding ability. All the synthesized compounds have been screened for their antitumor activities against various human cancer cell lines viz., Human breast adenocarcinoma cell line (MCF-7), Human leukemia cell line (THP-1), Human prostate cancer cell lines (PC-3) and adenocarcinomic human alveolar basal epithelial cell lines (A-549). Interestingly, all the compounds showed significant anticancer activity.

Iron(III) complexes with 2-aminobenzothiazole: compounds governed by non-covalent interactions

Two new iron(III) coordination compounds with 2-aminobenzothiazole have been prepared and identified as (C6H4NHC(NH2)S)2[FeCl4]Cl(H2O) (1) and (C6H4NHC(NH2)S)3[Fe(C2O4)3](H2O)2 (2). The compounds were characterized by thermogravimetric analysis in conjunction with evolved gases in air and spectroscopic studies. On the basis of quantum-mechanical calculations the interplay between two non-covalent interactions in 1, anion ··· π and ion-pair interactions, was analyzed.

Coordination sphere geometry changes of lanthanoid(III) nitrate complexes with hexamethylenetetramine

The 1 : 2 adducts of lanthanoid nitrate complexes with hexamethylenetetramine (hmta) have been synthesized and characterized by X-ray crystallography, IR spectroscopy, and bond valence calculations. The effect of lanthanoid contraction is observed. The lanthanoids create three isostructural groups: La–Nd (group I), Sm–Gd (group II), and Dy–Lu (group III). As an example, one structure for each group is presented in detail. There is a change in the composition of the lanthanoid coordination sphere, geometry, and coordination number with changing size of the lanthanoid. As the ionic radii decrease, the number of water molecules increases, whereas the nitrate ions move outside the inner coordination shell forming three isostructural groups. The hmta molecules are not coordinated to the central atom. Group I is formed by 10-coordinate complexes with the nitrate ions and water molecules in the inner and outer coordination sphere ([Ln(NO3)2(H2O)6]+ · · 2hmta · 2H2O). Group II includes the adducts of general formula ([Ln(NO3)(H2O)7]2+ · 2 · 2hmta · 3H2O) with nine-coordinate lanthanoid. Group III consists of eight-coordinate lanthanoid with general formula [Ln(H2O)8]3+ · 3 · 2hmta · 2H2O].

Halogen, hydrogen and electrostatic interactions in 2-amino-5-chloro-1,3-benzoxazol-3-ium nitrate and 2-amino-5-chloro-1,3-benzoxazol-3-ium perchlorate.

In the title compounds, C(7)H(6)ClN(2)O(+).NO(3)(-) and C(7)H(6)ClN(2)O(+).ClO(4)(-), the ions are connected by N-H...O hydrogen bonds and halogen interactions. Additionally, in the first compound, co-operative pi-pi stacking and halogen...pi interactions are observed. The energies of the observed interactions range from a value typical for very weak interactions (1.80 kJ mol(-1)) to one typical for mildly strong interactions (53.01 kJ mol(-1)). The iminium cations exist in an equilibrium form intermediate between exo- and endocyclic. This study provides structural insights relevant to the biochemical activity of 2-amino-5-chloro-1,3-benzoxazole compounds.

Structural elucidation and physicochemical properties of mononuclear Uranyl(VI) complexes incorporating dianionic units.

Two derivatives of organouranyl mononuclear complexes [UO2(L)THF] (1) and [UO2(L)Alc] (2), where L = (2,2′-(1E,1′E)-(2,2-dimethylpropane-1,3-dyl)bis(azanylylidene, THF = Tetrahydrofuran, Alc = Alcohol), have been prepared. These complexes have been determined by elemental analyses, single crystal X-ray crystallography and various spectroscopic studies. Moreover, the structure of these complexes have also been studied by DFT and time dependent DFT measurements showing that both the complexes have distorted pentagonal bipyramidal environment around uranyl ion. TD-DFT results indicate that the complex 1 displays an intense band at 458.7 nm which is mainly associated to the uranyl centered LMCT, where complex 2 shows a band at 461.8 nm that have significant LMCT character. The bonding has been further analyzed by EDA and NBO. The photocatalytic activity of complexes 1 and 2 for the degradation of rhodamine-B (RhB) and methylene blue (MB) under the irradiation of 500W Xe lamp has been explored, and found more efficient in presence of complex 1 than complex 2 for both dyes. In addition, dye adsorption and photoluminescence properties have also been discussed for both complexes.

2,3-Dihydro-1,3-benzothiazol-2-iminium monohydrogen sulfate and 2-iminio-2,3-dihydro-1,3-benzothiazole-6-sulfonate: a combined structural and theoretical study.

The 2-aminobenzothiazole sulfonation intermediate 2,3-dihydro-1,3-benzothiazol-2-iminium monohydrogen sulfate, C(7)H(7)N(2)S(+).HSO(4)(-), (I), and the final product 2-iminio-2,3-dihydro-1,3-benzothiazole-6-sulfonate, C(7)H(6)N(2)O(3)S(2), (II), both have the endocyclic N atom protonated; compound (I) exists as an ion pair and (II) forms a zwitterion. Intermolecular N-H...O and O-H...O hydrogen bonds are seen in both structures, with bonding energy (calculated on the basis of density functional theory) ranging from 1.06 to 14.15 kcal mol(-1). Hydrogen bonding in (I) and (II) creates DDDD and C(8)C(9)C(9) first-level graph sets, respectively. Face-to-face stacking interactions are observed in both (I) and (II), but they are extremely weak.

2,3-Dihydro-1,3-benzothiazol-2-iminium hydrogen oxydiacetate: a combined structural and theoretical study

In the title compound, C(7)H(7)N(2)S(+).C(4)H(5)O(5)(-), the ions are connected by N-H...O hydrogen bonds. The hydrogen oxydiacetate residues are linked together by O-H...O hydrogen bonds disordered about centres of inversion into hydrogen-bonded ribbon layers crosslinked by weak C-H...O and stacking interactions. The cation exists mainly in the 2,3-dihydro-1,3-benzothiazol-2-iminium form, with a small participation of the 2-aminobenzothiazolium form, based on the structural data and quantum mechanical calculations. This study provides structural insights relevant to the biochemical activity of benzothiazole molecules.

Pd(II) complexes based on quinoline derivative: Structural characterization and their role as a catalyst for hydrogenation of (E)-1-methyl-4-(2-nitrovinyl)benzene

A series of two new Pd(II) complexes with ligand, HL, (z)-2-((quinolin-3-ylimino)methyl)phenol, derived from 3-aminoquinoline and 2-hydroxybenzaldehyde was reported. The structure of ligand, HL was determined by single crystal X-ray diffraction. The ligand, HL crystallizes in the space group P21/n of the monoclinic system with unit cell dimensions a=8.8733(8), b=6.3318(5), c=11.5145(9). The reaction of ligand, HL with PdX2 [X=Cl(-), OAc] in 2:1molar ratio yielded complexes of the type [Pd(HL)2X2] [X=Cl(-), OAc]. The ligand, HL and its Pd(II) complexes were characterized by various physico-chemical techniques; elemental analyses, ionization mass spectrometry (ESI-MS), UV/Vis, FT-IR, (1)H and (13)C NMR spectroscopy. UV/Vis absorption studies showed a square planar geometry around Pd (II) ion. The selective hydrogenation of (E)-1-methyl-4-(2-nitrovinyl)benzene in ethanol using synthesized Pd(II) complexes as catalysts was investigated at room temperature. The Pd(II) complexes catalyzed the hydrogenation of (E)-1-methyl-4-(2-nitrovinyl)benzene to (E)-1-methyl-4-(2-aminovinyl) benzene. Furthermore, the catalytic activity increased with increasing the quantity of Pd(II) complexes as catalysts.

The Novel Polymorphic Form of Bis(3,5,7-triaza-1-azoniatricyclo[]decane) bis(-oxo)-tris(-oxo)-nonakis(-oxo)-nonaaqua-decaoxo-hepta-molybdenum-di-zinc(II) dihydrate, Synthesis, and Properties

The reaction of molybdophosphoric acid with zinc carbonate followed by addition of hmta leads to formation of a triclinic polymorph of bis(3,5,7-triaza-1-azoniatricyclo[]decane) bis(-oxo)-tris(-oxo)-nonakis(-oxo)-nonaaqua-decaoxo-hepta-molybdenum-di-zinc(II) dihydrate in a one pot simple reaction. The obtained compound has been characterised by IR, UV-Vis spectroscopy, elemental analysis, and X-ray crystallography. A detailed comparison between both polymorphic forms: triclinic  A,  A,  A, , , , and  A3 and monoclinic  A,  A,  A, , , , and  A3 was performed. The influence of the synthesis procedure on polymorph formation was described.