Thieno[2,3-b]pyridine-2-carbohydrazide in Polyheterocyclic Synthesis: The Synthesis of Pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine,Pyrido[3′,2′:4,5]thieno[3,2-d][1,2,3]triazine,and Pyrazolyl,Oxadiazolylthieno[2,3-b]pyridine Derivatives

Pyrdine-2(1H)-thione 1 reacted with ethyl chloroacetate 2 to give 2-S-ethoxy-carbonylmethylpyridine derivative 3, which could be cyclized into thieno[2,3-b]-pyridine-2-carbohydrazide derivative 5 by boiling with hydrazine hydrate. The latter compound reacted with cinnamonitrile derivatives 6a, b, triethylorthoformate, formic acid, dimethylformamide-dimethylacetal, and diethyl carbonate to give the corresponding shiff base 7a, b and pyrido[3′,2′;-4,5]thieno[3,2-d]pyrimidine derivatives 10–13 in respective manner. On the other hand, compound 5 also reacted with carbondisulphide and phenyl isothiocyanate to afford the corresponding 2-(1,3,4-oxadiazolo-2-yl)thieno[2,3-b]pyridine derivatives 18 and 22. Finally, compound 5 reacted with some β-dicarbonyl compounds, such as ethyl acetoacetate, acetylacetone and ethyl β-arylazoacetoacetate, to yield the corresponding 2-(pyrazol-1-yl-carbonyl)thieno[2,3-b]pyridine derivatives 24, 25, and 27 respectively.     

Extensions of TOPSIS for large scale multi-objective non-linear programming problems with block angular structure

This paper focuses on multi-objective large-scale non-linear programming (MOLSNLP) problems with block angular structure. We extend the technique for order preference by similarity ideal solution (TOPSIS) to solve them. Compromise (TOPSIS) control minimizes the measure of distance, provided that the closest solution should have the shortest distance from the positive ideal solution (PIS) as well as the longest distance from the negative ideal solution (NIS). As the measure of “closeness” L_P-metric is used. Thus, we reduce a q-dimensional objective space to a two-dimensional space by a first-order compromise procedure. The concept of a membership function of fuzzy set theory is used to represent the satisfaction level for both criteria. Moreover, we derive a single objective large-scale non-linear programming (LSNLP) problem using the max–min operator for the second-order compromise operation. Finally, a numerical illustrative example is given to clarify the main results developed in this paper.     

DNA Binding and Equilibrium Investigation of the Interaction of a Model Pd(II) Complex with Some Selected Biorelevant Ligands

The Pd(DAP)Cl₂ complex, where DAP is 2,6-diaminopyridine, was synthesized and characterized. The stoichiometries and stability constants of the complexes formed between various biologically relevant ligands (amino acids, amides, DNA constituents, and dicarboxylic acids) and [Pd(DAP)(H₂O)₂]²⁺ were investigated at 25 °C and at constant 0.1 mol·dm^?3 ionic strength. The concentration distribution diagrams of the various species formed were evaluated. A further investigation of the binding properties of the diaqua complex [Pd(DAP)(H₂O)₂]²⁺ with calf thymus DNA (CT-DNA) was investigated by UV–Vis spectroscopy. The intrinsic binding constants (K _b) calculated from UV–Vis absorption studies is 1.04 × 10³ mol·dm^?3. The calculated (K _b) value was found to be of lower magnitude than that of the classical intercalator EB (ethidium bromide) (K _b = 1.23 (±0.07) × 10⁵ mol·dm^?3), suggesting an electrostatic and/or groove binding mode for the interaction with CT-DNA.     

Novel pyrimidinone derivatives: synthesis, antitumor and antimicrobial evaluation

Starting from 6-aryl-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile (4a-d), a series of mono- and dialkyl derivatives 5a-j and 6a, b was synthesized. Hydrazinolysis of 4a, b, d and 5d afforded the hydrazino derivatives 7a-c which were cyclised to give the triazolopyrimidinones 8a-c and the pyrimidotriazinones 9a-c through the reaction with formic acid and chloroacetyl chloride, respectively. Most of the newly synthesized compounds were evaluated for their in-vitro antitumor activity. Compounds 6a and b displayed promising anticancer activity against leukaemia, non-small cell lung, melanoma, and renal cancer. On the other hand, all compounds prepared were screened for their in-vitro antibacterial and antifungal activities. Compounds 5h and j showed significant activity against Staphylococcus aureus, while compounds 5e, 7c and 8c displayed moderate inhibitory activity against Candida albicans.     

The effect of external and internal diffusion on the sorption of radioactive ions by reactive cloth filter: Part I

In this study, a new mathematical model was suggested to account for the effect of internal and external diffusion on fluid–solid noncatalytic reactions. The special features of this model are the combination of the transport processes and the chemical reaction kinetics with the added factor due to the structural properties of the solid reactant. The model was examined theoretically and experimentally. A reactive cloth filter that separates radionuclides from radioactive waste solutions is used as a practical application for the model. Analyses of the respective rate data in accordance with another two theoretical models showed that process is controlled by the rate of the diffusion step. The external and internal mass transfer constants across the liquid film and the resin matrix were determined from the graphical representation of the proposed model. The practical validation with the theoretical results offered satisfactory agreement at most of the process stages.     

Infrared Spectroscopic Study of γ-Irradiated Cotton Linters

Cotton linters is irradiated by Co-60 source with different doses (5 … 52 Mrad). The effect of γ-irradiation on the grafting of cotton linters with methylmethacrylate monomer (MMA) is clarified, crystallinity index (CrI) of irradiated samples decreases by increasing the radiation dose. A new hand appeared at 1715 cm^?1 (C=O) after irradiation. On the other hand, band intensities of some groups at 1600 cm^?1 (RCOO) are increased or decreased, e.g. OH at 3350 cm^?1 by irradiation.     

Redox, thermodynamic and spectroscopic of some transition metal complexes containing heterocyclic Schiff base ligands

Complexes of two series of Schiff base ligands, H₂L_a and H₂L_bderived from the reaction of 2,6-diacetyl pyridine with semicarbazide, H₂L_a and thiosemicarbazide, H₂L_b, with the metal ions, Co(II), Ni(II), Cu(II), VO(IV) and UO₂(VI) have been prepared. The ligands are characterized by elemental analysis, IR, UV–vis and ¹H NMR. The structures of the complexes are investigated with the IR, UV–vis, X-band ESR spectra, ¹H NMR and thermal gravimetric analysis as well as conductivity and magnetic moment measurements. The IR-spectra reveal the presence of variable modes of chelation for the investigated ligands. A variety of binuclear or mononuclear complexes were obtained with the two ligands in tri-, tetra or pentadentate forms. The bonding sites are the pyridine nitrogen, two azomethine nitrogen atoms and ketonic oxygen in case of H₂L_a or sulphur atoms in case of H₂L_b. The Coats–Redfern equation has been used to calculate the kinetic and thermodynamic parameters for the different thermal decomposition steps of some complexes. Cyclic voltammograms of Co(II) and Ni(II) show quasi-reversible peaks. The redox properties and the nature of the electro-active species of the complexes have been characterized.