Synthesis,Characterization, and Antibacterial Activities of Organotin(IV) Complexes with 2‐Acetylpyridine‐N(4)‐cyclohexylthiosemicarbazone (HAPCT)

The reaction of 2‐acetylpyridine‐N(4)‐cyclohexylthiosemicarbazone [(HAPCT), ( 1 )] ligand with organotin(IV) chloride(s) afforded the five new organotin(IV) complexes: [MeSnCl₂(APCT)] ( 2 ), [BuSnCl₂(APCT)] ( 3 ), [PhSnCl₂(APCT)] ( 4 ), [Me₂SnCl(APCT)] ( 5 ), and [Ph₂SnCl(APCT)] ( 6 ). The ligand ( 1 ) and its organotin(IV) complexes ( 2–6 ) have been synthesized and characterized by CHN analyses, molar conductivity, UV–vis, FT IR, ¹H, ¹³C, and ¹¹⁹Sn NMR spectral studies. The single crystal X‐ray diffraction studies indicated that [PhSnCl₂(APCT)] ( 4 ) is six coordinated and strongly adopts a distorted octahedral configuration with the coordination through pyridine‐N, azomethine‐N, and thiolato‐S atoms of the ligand. The compound crystallizes into a monoclinic lattice with the space group P21/n. The ligand ( 1 ) and its organotin(IV) complexes ( 2–6 ) were assayed for in vitro antibacterial activity against Staphylococcus aureus, Escherichia coli, Enterobacter aerogenes, and Salmonella typhi. The screening results have shown that the organotin(IV) complexes ( 2–6 ) have better antibacterial activity than the free ligand. Furthermore, it has been shown that the diphenyltin(IV) derivative ( 6 ) exhibits significantly better activities than the other organotin(IV) derivatives ( 2–5 ). © 2012 Wiley Periodicals, Inc. Heteroatom Chem 24:43–52, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21061     

Structural diversity in phosphoramidate’s chemistry: Syntheses,spectroscopic and X-ray crystallography studies

Novel phosphorus compounds of bisphosphoramidate, phosphoramidate and phosphoric triamide derivatives were synthesized using the starting materials PCl₅ and POCl₃. The products were then characterized by ¹H, ¹³C, ³¹P, ¹⁹F NMR, IR spectroscopy and CHN elemental analysis. It is noticeable that the reaction of 4-aminobenzamide with PCl₅ in different molar ratios yields different products, bisphosphoramides and phosphoric triamides. Moreover, we were taken by surprise that the interaction of POCl₃ with the first-type aromatic amines gave bisphosphoramidates with P–N–P linkages that exhibited ²J(P,P) ≈ 20.0 Hz in the ³¹P NMR spectra. In fact, two simple one-pot pathways are presented here for the synthesis of new bisphosphoramidates, and to the best of our knowledge these are the first instances of bisphosphoramidates that have been obtained up until now. The structures of compounds I (4-OCH₃–C₆H₄–CH₂–C₉H₁₃–NH₂Cl), 34 and 44 were further determined by X-ray crystallography. All of these structures produced three dimensional polymeric chains through strong- and weak hydrogen bonds. The presence of chiral aminoacidester moieties in the phosphoric triamides lead to chiral molecules that showed two sets of signals for the two groups. Interestingly, in phosphoric triamides containing cyanoacetamide moieties, the existence of aromatic amine substituents on the P atoms created central chiral phosphorus atoms, i.e. the two aromatic groups revealed two sets of peaks in the ¹H and ¹³C NMR spectra, while compounds with aliphatic moieties did not display this effect.     

New organophosphorus compounds containing nicotinamide: synthesis,structure and DFT calculations

Novel organophosphorus compounds, containing Nicotinamide, with formula C₅H₄NC(O)NHP(O)R₂, R=Cl (1), OH (2), N(C₂H₅)₂ (3), N(C₃H₇)₂ (4), N(n-C₄H₉)₂ (5), NHC₃H₅ (6), NHC₅H₉ (7), were synthesized and characterized by ¹H, ¹³C, ³¹P, NMR, IR, spectroscopy and elemental analysis. Single crystal structures of 3 7 were determined by X-ray crystallography. ¹HNMR spectra of compounds 2, 3, 6–8 demonstrated interesting long-range coupling constant, ⁿ J _P,H (n = 5 7). Crystallographic data revealed that in both molecules 3 and 7, the phosphoryl and the carbonyl groups have anti-configurations and the phosphorus atoms in these structures have distorted tetrahedral configuration. All the hydrogen bonds and electrostatic interactions make a three dimensional polymeric network for both 3 and 7. Interestingly, two independent conformers were detected in the unit cell of compound 7. The two conformers of the title compound can be observed in a solid phase but only one compound defined in a solution. These two conformers are connected to each other by a short contact, N (amine)···H–C (pyridine) with 2.626 Å distance. The molecular geometry of 7 was calculated by DFT/B3LYP (6–31+G**) quantum chemical calculations. The computational optimized geometric parameters and vibrational frequencies showed a good agreement with the experimental results, considering reasonable variations arising from the differences between solid and gaseous phases. Theoretical calculations revealed that the more stable conformer of the title compound is conformer 1 with the energy of ?1335.723996 a.u., which is about 1.17 kcal/mol lower than the energy of conformer 2.     

Cu–S‐(propyl)‐2‐aminobenzothioate on magnetic nanoparticles: highly efficient and reusable catalyst for synthesis of polyhydroquinoline derivatives and oxidation of sulfides

Cu–S‐(propyl)‐2‐aminobenzothioate supported on functionalized Fe₃O₄ magnetic nanoparticles is reported as a reusable and highly efficient nanocatalyst for the one‐pot synthesis of polyhydroquinoline derivatives and also for selective oxidation of sulfides to sulfoxides. The prepared nanoparticles were characterized using Fourier transform infrared spectroscopy, vibrating sample magnetometry, thermogravimetric analysis, transmission and scanning electron microscopies, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, inductively coupled plasma atomic emission spectroscopy and atomic absorption spectroscopy. The nanocatalyst was easily recovered using an external magnet and reused several times without significant loss of its catalytic efficiency. Copyright © 2016 John Wiley & Sons, Ltd.     

Solvent-free synthesis of new spiropyrroloindole compounds using Fe3O4/TiO2/MWCNTs MNCs via multicomponent reactions: assessment of new spiropyrroloindole antioxidant activity

In this study, water extract of Spinacia oleracea leaves was used for the synthesis of Fe₃O₄/TiO₂/MWCNTs magnetic nanocomposites and high performance of this catalyst was confirmed by employing it in the solvent-free multicomponent reactions of anilines, oxalyl chloride, diamines or hydroxyamines, electron-deficient acetylenic ester, α-haloketones and Et₃N at room temperature for the generation of new spiropyrroloindoles in high yields. This catalyst could be utilized several times and has a significant role in the yield of product. The synthesized spiropyrroloindoles have NH and OH group in their structure and for this reason have good antioxidant activity. Also, by employing Gram-positive and Gram-negative bacteria and the disk diffusion procedure confirmed the antimicrobial effect of some spiropyrroloindole derivatives. The results showed that synthesized spiropyrroloindoles prevented the bacterial growth. This used process for preparation of new spiropyrroloindoles has some improvements such as low reaction time, product with high yields, and simple separation of catalyst and products.

Graphical abstract

     

Oxygen Reduction Reaction on a Rotating Ag/GC Disk Electrode in Acidic Solution

Finding an appropriate mechanism of oxygen reduction reaction, without having kinetic parameters and intermediate species at hand, is an impossible task. In view of the fact that this reaction is one of the important reactions, it was tried to overcome this problem through computing the kinetic parameters by means of Ag/GC rotating disc electrode in an acidic solution. Using this electrode, two values were obtained for electron transfer coefficient and reaction order was calculated through relative equations. Based on this information, an ECE (electrochemical chemical electrochemical) mechanism has been proposed.     

A simple and effective approach to the synthesis of rhodanine derivatives via three-component reactions in water

A facile and direct synthetic entry to rhodanine derivatives via the three-component coupling of carbon disulfide, primary amines, and acetylenic esters under neutral conditions in water is reported.     

HYERS-ULAM-RASSIAS STABILITY OF FUNCTIONAL EQUATIONS IN MENGER PROBABILISTIC NORMED SPACES

We introduce the approximately quadratic functional equation in Menger probabilistic normed spaces. More precisely, we show under some suitable conditions that an approximately quadratic functional equation can be approximated by a quadratic function in above mentioned spaces. Also we consider the stability problem for approximately pexiderized functional equation in Menger probabilistic normed spaces.     

Analysis of rat testicular proteome following 30‐day exposure to 900 MHz electromagnetic field radiation

The use of electromagnetic field (EMF) generating apparatuses such as cell phones is increasing, and has caused an interest in the investigations of its effects on human health. We analyzed proteome in preparations from the whole testis in adult male Sprague‐Dawley rats that were exposed to 900 MHz EMF radiation for 1, 2, or 4 h/day for 30 consecutive days, simulating a range of possible human cell phone use. Subjects were sacrificed immediately after the end of the experiment and testes fractions were solubilized and separated via high‐resolution 2D electrophoresis, and gel patterns were scanned, digitized, and processed. Thirteen proteins, which were found only in sham or in exposure groups, were identified by MALDI‐TOF/TOF‐MS. Among them, heat shock proteins, superoxide dismutase, peroxiredoxin‐1, and other proteins related to misfolding of proteins and/or stress were identified. These results demonstrate significant effects of radio frequency modulated EMFs exposure on proteome, particularly in protein species in the rodent testis, and suggest that a 30‐day exposure to EMF radiation induces nonthermal stress in testicular tissue. The functional implication of the identified proteins was discussed.