Template reactions of 2-hydroxy-R-benzaldehyde-S-methylisothiosemicarbazones (R= 3methoxy or 4-hydroxy) with the corresponding aldehydes in the presence of FeCl 3 and NiCl 2 yielded N 1 ,N 4 -disalicylidene chelate complexes. The compounds were characterized by means of elemental and spectroscopic methods. The structure of complex 1 was determined by x-ray single crystal diffraction. Crystal data (Mo Kα; 296 K) are as follows: monoclinic space group P2 1 /c, a = 12.9857(8) Å, b = 7.8019(4) Å, c = 19.1976(12) Å, β = 101.655(5)°, Z = 4. Cytotoxic effects of the compounds were evaluated by MTT assay in K562 leukemia, ECV304 endothelial and normal mononuclear cells and DNA fragmentation analysis using the diphenylamine reaction were performed. The DNA binding capacity of thiosemicarbazones at IC 50 and different concentrations was investigated. The DNA fragmentation percentage of compound treated cells were higher than non-treated control cells but compound 3 (84%) was higher than the others. The interaction of compounds 1-4 and DNA was investigated voltammetrically by using nucleic acids modified electrodes after the double stranded fish sperm DNA (fsDNA), or poly (dA).poly (dT) was immobilized onto the surface of pencil graphite electrodes (PGEs). Accordingly, the oxidation signals of DNA bases; guanine and adenine were measured by using differential pulse voltammetry (DPV). The changes at the signals of guanine and adenine were evaluated before and after interaction process. The results indicated compound 3 was cytotoxic in very low concentrations in K562 leukemia cells unlike other cells and that could damage the DNA double stranded form, specifically the adenine base. Therefore, it may be a selective antileukemic effect and drug potential.thiosemicarbazones. Generally, the transition metals play a very important role in an organism and their complexes can interact non-covalently with nucleic acid by intercalation, groove-binding or external electrostatic binding for cations. 3,7,[19][20][21][22] There have been numerous studies in the literature investigating drug-DNA interactions by using conventional techniques such as HPLC, GC, and mass spectrometry. Considering the numerous advantages of electrochemical analysis techniques, the disadvantages of these conventional techniques arising from their complicated form of analysis have made them less preferable. Since the electroactivity of nucleic acids was discovered in the 1960s, 29 electrochemical nucleic acid biosensors, known as electrochemical genosensors, have frequently been preferred for recognition of (bio)molecule-DNA interactions. There are several research articles that investigated (bio)molecule-DNA interaction by using electrochemical techniques in the literature. [30][31][32][33][34][35][36] PGEs bring some crucial properties such as being robust, single-use, practical and having a large surface area. Their combination with electrochemical detection techniques provides fast, practical, accurate and time-saving analysis of target analytes. Moreover, th...

Pyridine-based tridentate triamine compounds ( 0 N kNkN 0 ) are very attractive ligands for coordination chemistry, and their transition-metal (TM) complexes have been successfully applied in homogeneous catalysis. 1À28 Although examples of the related Ru complexes are scarce, such complexes recently gained attention due to their use in catalysis and in other chemical applications. 29À48 For example, d N k N k N d -containing neutral Ru(II) complexes of the general formula [RuCl 2 ( d N k N k N d )L] (L = monodentate ligands such as CH 3 CN, PPh 3 , and CO) are effective catalysts for the transfer hydrogenation (TH) of ketones. 29,32 During the preparation of this paper, a report on unsymmetrical and asymmetrical [RuCl( 0 N k N k N 00 )(PPh 3 ) 2 ]Cl complexes which showed excellent TH activity has appeared. 49 On the other hand, Ru(II) complexes bearing chelating amine ligands such as N-sulfonated 1,2-diamines have been successfully used in the TH of acetophenone by Noyori and others. 50À63 However, in spite of these developments, there is still demand for stable and easily handled complexes prepared from cheap starting materials which make them preferred catalyst precursors. In comparison with the extensive chemistry of sulfonated 1,2-diamines, little research has been performed on pyridylsulfonamide compounds of the type C 5 H 4 NCH 2 NHSO 2 Ar, which are versatile bidentate ligands due to their ease of synthesis and variability of Ar groups. 64À68 Neutral sulfonamide ligands are expected to be poor ligands. Thus, the pyridyl-2-alkylsulfonamides generally coordinate to the metal center through the pyridyl nitrogen atom and the deprotonated nitrogen of the sulfonamide group. 69 However, Soltani et al. have recently shown that cationic Ir complexes containing neutral sulfonamide ligands are active catalysts for the TH of acetophenone derivatives in water. 70 More recently, Baratte and co-workers have shown that Ru(II) complexes containing nonsulfonated (2-aminomethyl)-pyridine ligands display excellent catalytic activity in the TH of ketones. 71 With the aim of contributing to the understanding of how geometric and electronic factors imposed by a combination of mixed tri-and bidentate ligands influence the catalyst performance, herein a series of novel Ru(II) complexes (1À10) were characterized and employed as catalysts for the TH of ketones.

No abstract

No abstract

In this article, direct N‐alkylation reactions of amines with alcohols derivatives have been investigated. For this purpose, a new series ruthenium (II) complexes bearing N‐coordinated benzimidazole complexes with have been synthesized and fully characterized by elemental analysis, FT‐IR, 1H NMR and, 13C NMR spectroscopies. Additionally, the structures of the complexes 2b and 2c have been confirmed by X‐ray crystallography. Although the N‐alkylating reaction is usually performed in toluene, the catalytic study of complexes 2a‐d has carried out no additional solvent and alcohol acted both as solvent and reactant of alkylating by using a little excess of alcohols. Surprisingly, conversion and selectivity of amine product for alkylation reaction have been seen high in medium solvent‐free relative to in toluene.

In the title compound, C15H19N5OS, the morpholine ring adopts a chair conformation. The mean plane of the pyridine ring makes a dihedral angle of 35.16 (7)° with the triazole ring plane.

No abstract

No abstract