Volume 73, Issue 6

Two transitional metal complexes, [Zn(oba)(3-bpcd)] n ( 1 ) and [Cd(oba)(3-bpcd) 0.5 ] n ( 2 ) [H 2 oba= 4,4′-oxybis(benzoic acid), 3-bpcd= N , N ′-bis(pyridin-3-yl)cyclohexane-1,4-dicarboxamide], have been hydrothermally synthesized and structurally characterized by elemental analyses, infrared spectra, powder X-ray diffraction, thermogravimetric and single-crystal X-ray diffraction. Complex 1 possesses a three-fold interpenetrating network based on layers with a 4-connected sql topology. Complex 2 is a layered framework constructed by the oba anions and 3-bpcd ligands, which represents a binodal (3,4)-connected {6 2 .10}{6} topology. The adjacent layers of complex 2 are further linked by hydrogen bonding interactions to build a three-dimensional supramolecular architecture. The differences of metal ions in coordination modes show a significant effect on the final structures of the Zn(II)/Cd(II) complexes. The photocatalytic activities and the fluorescence sensing properties of complexes 1 and 2 were investigated.

A mixed ligand zinc coordination polymer, {Zn( μ -DPE)(DBM) 2 } n ( 1 ) (HDBM: dibenzoylmethane and DPE: ( E )-1,2-di(pyridin-4-yl)ethene), was prepared and identified by elemental analysis, FT-IR, 1 H NMR spectroscopy and single-crystal X-ray diffraction. In the 1D linear coordination polymer of 1 , the zinc atom has a ZnN 2 O 4 environment with octahedral geometry. These complex units are linked by the bridging of the planar N 2 donor DPE ligands. In the coordination network of complex 1 , in addition to the hydrogen bonds, the network is more stabilized by π–π stacking interactions between pyridine and β -diketone moieties of the ligands. These interactions increase the ability of the compound to interact with biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS and Top II) as investigated by docking calculations.

A new iridoid glycoside, namely, cymdahoside A ( 1 ), together with two known ones, 2 and 3 , were isolated from the EtOAc extract of Cymbaria dahurica . The structure elucidation of 1 was carried out by one-dimensional (1D) NMR ( 1 H and 13 C NMR) and 2D NMR (correlation spectroscopy, heteronuclear single-quantum coherence, heteronuclear multiple-bond correlation and nuclear Overhauser effect spectroscopy) spectral analyses.

Two new alkylresorcinol derivatives, namely ochocinone A and ochocinone B ( 1 , 2 ), as well as a known alkylresorcinol oleiferinone ( 3 ) were isolated from the methanol extract of the leaves of Scyphocephalium ochocoa . The structures of these compounds were established by detailed spectroscopic analysis and by comparison with the spectral data of related known compounds. Compounds 1–3 showed significant immunomodulatory activity and cytotoxic effect on the mammary carcinoma MCF-7 cell line.

A new series of chalcones, pyrazolinyl-pyrazoles, pyrazole-4-carbaldehyde oximes, pyrazole-4-carbonitriles, 5-pyrazolyl-1,2,4-triazolidine-3-thiones, and Knoevenagel condensation products was synthesized from 3-aryl-1-phenyl-1 H -pyrazole-4-carbaldehydes. Most reactions were carried out either without solvent or in the presence of water as a green solvent. The structure of synthesized compounds was characterized by spectral and elemental analysis. The synthesized compounds were tested in vitro for their antimicrobial activity against Escherichia coli , Staphylococcus aureus , and Candida albicans in comparison with imipenem (intravenous β -lactam antibiotic) and clotrimazole (antifungal medication) as reference drugs by using the agar diffusion technique. 3-Aryl-1-phenyl-1 H -pyrazole-4-carbonitriles 8b , 8c , and 8d showed significant antifungal activity against the fungus C. albicans .

The reactivity of N -2-(2-aminobenzoyl)- N -phenylhydrazinecarbothioamide ( 1 ) as an electron donor toward several electron-accepting compounds through electron donor-acceptor interaction has been studied. Thus, upon treatment of 1 with either 1,4-naphthoquinone, 2-dicyanomethyleneindan-1,3-dione, or 2,3-dichloro-1,4-naphthoquinone, the reaction proceeds to give thiadiazino[5,4- b ]quinazoline, N -phenylcarbamohydrazonothioate, and thiadiazine-5,10-dione, respectively. Also, the reactivity of compound 1 toward some aldehydes and anhydrides was studied. The products were fully characterized by their spectral data. The mechanisms of formation of the products have been rationalized.

The hydrothermal reaction of ZnSO 4 with 2,5-di(1 H -imidazol-4-yl)thiophene (L) at 100°C yields a new complex [Zn(L)(SO 4 )] n ( 1 ). Complex 1 has been characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental and thermogravimetric analyses. It crystallizes in the monoclinic system, space group P 2 1 / c with Z =4, and shows a (4 4 .6 2 ) network structure. Complex 1 shows fluorescence. Single crystals of L·2H 2 O were accidentally obtained in hydrothermal reaction attempts of L with MnCl 2 at 120°C.

The reaction of 3-alkyl(aryl)imidazo[1,5- a ]pyridines ( 1 ) with ninhydrin in dichloromethane at room temperature delivered good yields of the respective 2-hydroxy-2-(imidazo[1,5- a ]pyridine-1-yl)indene-1,3-diones. In the presence of dimethyl acetylenedicarboxylate (DMAD), this uncatalyzed electrophilic substitution reaction, involving C-1 (in 1 ) and the central C=O (in ninhydrin), takes precedence over the three-component 1,4-dipolar cycloaddition reaction. This selectivity is probably due to the higher electrophilicity of the carbonyl carbon-2 in ninhydrin as compared to that of the sp -carbon atoms in DMAD, augmented with the high nucleophilicity of carbon-1 in 1 .

New silver complex [Ag(pz)(CF 3 SO 3 )] ( 1 ) was formed by the coordination reaction of AgCF 3 SO 3 with pyrazine (pz) in the presence of 2-[( S )-4-isopropyl-2-oxazolyl] quinoline (L). When AgBF 4 was used instead of AgCF 3 SO 3 as the starting material, complex 2 [Ag(L)(CH 3 CN)](BF 4 ) was obtained. Complexes 1 and 2 are characterized by single-crystal X-ray diffraction, IR spectroscopy and elemental, and thermogravimetric analysis. Complex 1 shows a 3D framework structure with uni-nodal eight-connected (4 24 .6 4 ) topology while complex 2 displays a discrete mononuclear structure. The nonlinear optical properties of 2 were investigated.