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This study focuses on the synthesis, characterization, and kinetics of substitution reaction of new uranyl Schiff base complexes prepared in a crystalline state as well as in a form of nanoparticles with sizes ranging between 35 and 60 nm. Preliminary Fourier transform infrared spectroscopy (FTIR) and thermogravimetric (TG) measurements indicated no difference between the two forms. The compounds were characterized by UV–vis, 1H NMR, cyclic voltammetry, X-ray crystallography, FTIR, TG, and CHN analyses. X-ray crystallography revealed coordination of the uranyl by the tetradentate Schiff base ligand and one solvent molecule, resulting in seven-coordinated uranium. Cyclic voltammetry of the complexes in acetonitrile revealed the quasi-reversible redox reaction. The TG and analysis of Coats–Redfern plots revealed that the kinetics of thermal decomposition of the complexes is of the first order in all stages. The study of the kinetics and the mechanism of the exchange reaction of the coordinated solvent with tributylphosphine was performed by the spectrophotometric method. The second-order rate constants at four temperatures and the activation parameters revealed an associative mechanism for all corresponding complexes. Anticancer activity of the nano uranyl Schiff base complexes against cancer cell lines (Jurkat) was studied and determined by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazoliumbromide) assay.

A novel heterogeneous catalyst was developed via the immobilization of a copper complex by covalent anchoring of the ligand on the surface of magnetic nano particles. The catalyst was characterized by various techniques including Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron micrograph (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), a vibrating sample magnetometer (VSM) and inductively coupled plasma (ICP) spectroscopy. The prepared catalyst demonstrated high catalytic activity, stability, reproducible dispersibility, and recycability in the O-arylation reactions. Moreover, the catalyst could be easily recovered under the outside magnetic field and reused without noticeable decreasing in its catalytic performance upon five consecutive runs.

The properties of the ExB drift mode in Hall thrusters were investigated through particle-based simulations. Two different two-dimensional models coupling the ExB drift azimuthal direction with the axial accelerating field and radial magnetic field directions, respectively, were implemented assuming Cartesian slab geometry. While the azimuthal-axial model is self-sustaining through the closure of the anode-cathode circuit, the radial-azimuthal one is equipped with an injection system that preserves the number of ions and with a secondary electron emission module for electron-wall interaction. Results identify the linear growth and nonlinear saturation mechanisms consisting of electron heating along azimuthal and radial directions and of ion wave trapping. The latter leads to the ion rotation along the azimuthal direction giving the ion distribution a long tail. The discrete band structure of ExB electron drift instability evolves by an inverse cascade process toward small wavenumbers characterized by broader resonances giving to the spectrum an ion-acoustic-like nature. The larger lobes are due to electron heating and to the presence of a radial component by a modified two-stream instability. Important correlations at macroscopic level between the azimuthal modulation of the azimuthal electric field and the axial modulation of the accelerating field are proof of the complexity of the electron transport in Hall thrusters.

Uranyl(VI) complexes [UO2(L)(solvent)], where L denotes an asymmetric N2O2 Schiff base (salpyr, 3-MeOsalpyr, 4-MeOsalpyr, 5-MeOsalpyr, 5-Clsalpyr or 5-Brsalpyr; salpyr is N,N′-bis(salicyliden)-2,3-diaminopyridine), were synthesized and characterized in solution (UV–vis, 1H NMR, cyclic voltammetry) and in the solid-state (X-ray crystallography, IR, TGA, C H N.). X-ray crystallography of UO2(3-MeOsalpyr) revealed coordination of the uranyl by the tetradentate Schiff base and one disordered solvent, resulting in seven-coordinate uranium. Another disordered solvent was not coordinated. Cyclic voltammetry of [UVIO2(L)(solvent)] in acetonitrile was used to investigate the effect of the substituents of the Schiff base ligands on oxidation and reduction potential. The quasi-reversible redox reaction without any successive reactions was accelerated by groups with lesser electron withdrawing. We also investigated the kinetics and mechanism of the exchange reaction of the coordinated solvent with tributylphosphine u...

Kinetics of the substitution reaction of solvent molecule in uranyl(VI) Schiff base complexes by tri-n-butylposphine as the entering nucleophile in acetonitrile at 10–40°C was studied spectrophotometrically. The second-order rate constants for the substitution reaction of the solvent molecule were found to be (8.8 ± 0.5) × 10−3, (5.3 ± 0.2) × 10−3, (7.5 ± 0.3) × 10−3, (6.1 ± 0.3) × 10−3, (13.5 ± 1.6) × 10−3, (13.2 ± 0.9) × 10−3, (52.9 ± 0.2) × 10−3, and (88.1 ± 0.6) × 10−3 M−1 s−1 at 40°C for [UO2(Schiff base)(CH3CN)], where Schiff base = L1–L8, respectively. In a temperature dependence study, the activation parameters ΔH# and ΔS# for the reaction of uranyl complexes with PBu3 were determined. From the linear rate dependence on the concentration of PBu3, the span of k2 values and the large negative values of the activation entropy, an associative (A) mechanism is deduced for the solvent substitution. By comparing the second-order rate constants k2, it was concluded that the steric and the electronic properties of the complexes were important for the rate of the reactions.

UV–Vis. spectrophotometric study of the adduct formation of organotin(IV)trichlorides i.e. PhSnCl 3 and MeSnCl 3 as acceptors with Co(II) tetraaza complexes, such as [Co(ampen)] [N,N′-ethylenebis-(o-amino-α-phenylbenzylideneiminato)cobalt(II)], [Co(campen)] [N,N′-ethylenebis-(5-chloro-o-amino-α-phenylbenzylideneiminato)cobalt(II)], [Co(amaen)] [N,N′-ethylenebis-(o-amino-α-methylbenzylideneiminato)cobalt(II)], [Co(amppn)] [N,N′-propylene bis-(5-chloro-o-amino-α-phenylbenzylideneiminato)cobalt(II)] and [Co(camppn)] [N,N′-propylenebis-(5-chloro-o-amino-α-phenylbenzylideneiminato)cobalt(II)] as donors were studied spectrophotometrically under N 2 atmosphere and in N,N′-dimethylformamide solvent. The formation constants and thermodynamic parameters were measured using spectrophotometric titration of adduct formation at various temperatures. The trend of the adduct formations of the cobalt(II) tetraaza complexes with a given organotintrichloride acceptor decreases as follow: [Co(amaen)] > [Co(amppn)] > [Co(ampen)] > [Co(camppn)] > [Co(campen)]. The trend of the formation constants for the studied organotintrichlorides with a given cobalt(II) tetraaza complexes is as follow: PhSnCl 3 > MeSnCl 3 .

Some tetradentate N2O2 Schiff base ligands, such as N,N′-bis(naphtalidene)-1,2-phenylenediamine, N,N′-bis(naphtalidene)-4-methyl-1,2-phenylenediamine, N,N′-bis(naphtalidene)-4-chloro-1,2-phenylenediamine, N,N′-bis(naphtalidene)-4-nitro-1,2-phenylenediamine, N,N′-bis(naphtalidene)-4-carboxyl-1,2-phenylenediamine, and their uranyl complexes were synthesized and characterized by 1H NMR, IR, UV–Vis spectroscopy, TG (thermogravimetry), and elemental analysis (C.H.N.). Thermogravimetric analysis shows that uranyl complexes have very different thermal stabilities. This method is used also to establish that only one solvent molecule is coordinated to the central uranium ion and this solvent molecule does not coordinate strongly and is removed easier than the tetradentate ligand and also trans oxides. The electrochemical properties of the uranyl complexes were investigated by cyclic voltammetry. Electrochemistry of these complexes showed a quasireversible redox reaction without any successive reactions. Also, the kinetic parameters of thermal decomposition were calculated using Coats–Redfern equation. According to Coats–Redfern plots the kinetics of thermal decomposition of the studied complexes is first-order in all stages. Anticancer activity of the uranyl Schiff base complexes against cancer cell lines (Jurkat) was studied and determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide) assay.

The kinetics of the substitution reaction of uranyl Schiff base complexes with tributylphosphine was studied spectrophotometrically in acetonitrile. Uranyl complexes have a pentagonal bipyramidal structure with a trans-UO2 moiety at the axial positions. In uranyl tetradentate Schiff base complexes, the fifth position of the equatorial plane is occupied by the solvent molecule, which weakly coordinates to the U center. In a substitution reaction, tributylphosphine can easily replace the solvent molecule. By considering the excellent linearity of kobs versus the molar concentration of tributylphosphine, the large negative values of Δ S#, and the small values of Δ H#, an associative (A) mechanism has been suggested. By comparing the rate constants (k2) and the activation parameters, it is obvious that two parameters are effective in the rate of substitution reactions; The first parameter is the steric effect that the rate of reaction has been decreased by increasing this factor, and the other parameter is the electronic property that the electron-withdrawing group leads to increase the rate of reaction and the electron donor group decreases it. © 2013 Wiley Periodicals, Inc. Int J Chem Kinet 45: 168–174, 2013

A novel tetradentate Schiff base, naphthabza-H2 = N,N′-bis(naphthylidene)-2-aminobenzylamine, and a series of aluminum(III), gallium(III), and indium(III) complexes with general formula, MLNO3, were synthesized and characterized by elemental analysis, 1H NMR, FT-IR, UV–Vis spectroscopy and thermogravimetric method. The product of the reaction of complexes with hydrogen peroxide was characterized by similar techniques. According to the ab initio calculations aluminum and gallium complexes have five-coordinated structures and indium complex is a six-coordinated one. Also, the growth inhibitory effects of the complexes toward K562 cancer cell line were measured and the results for these complexes are as follows: Al > Ga > In.

According to the fact that providing service in rural community is done by health workers and based on the referral system the client refers to health workers first. so in case of not paying any attention to their performance, there will be a possibility of having problems. This research is sectional, applied and uses correlation method. The statistical society is consisted of health workers that were studied by census method. The data was analyzed by a psychometric , researcher-made questionnaire. After completing the questionnaire, the data was analyzed by using SPSS.According to the results, 4,6% had good awareness and 23,3% had a positive attitude and 100% had poor performance and fairly good. The results indicates that due to the role of health workers in the referral system , there is a requirement for identification and implementation of the factors that have a positive effect on this relationship. Keywords: Health worker; Referral system; Family Physician Program

Some new water soluble complexes [N,N'-bis{5-[(triphenyl phosphonium chloride)-methyl]salicylidine}-3,4-diaminopyridine] M(ii), which are formulated as nano-[Zn(5-CH2PPh3-3,4-salpyr)](ClO4)2 (), [Zn(5-CH2PPh3-3,4-salpyr)](ClO4)2 (), nano-[Ni(5-CH2PPh3-3,4-salpyr)](ClO4)2 (), [Ni(5-CH2PPh3-3,4-salpyr)](ClO4)2 (), and [N,N'-bis{5-[(triphenyl phosphonium chloride)-methyl]salicylidine}-2,3-diaminopyridine]Ni(ii) [Ni(5-CH2PPh3-2,3-salpyr)](ClO4)2 () have been isolated and characterized by elemental analysis, FT-IR, (1)H NMR, (13)C NMR, (31)P NMR, and UV-vis spectroscopy. The morphology and size of the nano complexes were determined using FE-SEM and TEM. In vitro DNA binding studies were investigated by UV-vis absorption spectroscopy, viscosity measurements, CD spectroscopy, cyclic voltammetry, emission spectra and gel electrophoresis, which suggest that the metal complexes act as efficient DNA binders. The absorption spectroscopy of the compounds with DNA reveals that the DNA binding affinity (Kb) has this order:Ligand. The metal complexes show DNA binding stronger than the ligand, which is expected due to the nature of the metal. The nano complexes display DNA binding stronger than the other complexes which is related to the effect of size on binding affinity and the Ni(ii) complexes reveal DNA binding stronger than the corresponding Zn(ii) analogues, which is expected due to their z* effect and geometry. The prominent double strand DNA cleavage abilities of compound are observed in the absence of H2O2 with efficiencies of more than 50% even at 70 μM complex concentration. Surprisingly, Zn(ii) complexes (compounds) exhibit a higher cytotoxicity (IC50: 7.310.9 μM at 24 h; IC50: 4.68.7 μM at 48 h) against human hepatoma (HepG2) and HeLa cell lines than the Ni(ii) complexes (compounds ,) and 5-fluorouracil as control in spite of their inability to cleave DNA. Finally, DNA binding interactions were performed by docking studies. Density functional theory (DFT) studies were performed using the GAUSSIAN 03 program. The DFT method with B3LYP functional, LANL2DZ basis set for metal centers and 6-311g* for other atoms was used. The synthesized compounds and DNA were simulated by molecular docking to explore more details of the ligands conformation and their orientations in the active site of the receptor.

In this paper, uranium sorption onto amberlite CG-400 anion exchange resin in the presence of phosphate anions was studied. The effect of contact time between the sorbent and aqueous solution, pH, initial concentration of uranium and temperature were also investigated. Kinetic studies show that uranium sorption onto amberlite CG-400 resin in the presence of phosphate is a fast process and follows pesudo-second-order kinetics. It was also found that the pH value and the presence of phosphate play very important roles in the uranium sorption onto CG-400 resin. Optimum pH for uranium sorption in the presence of phosphate anions was about 3.5. The experimental sorption isotherm is successfully described by Langmuir and Freundlich models. The maximum uranium sorption capacity was 57.14 and 112.36 mg g−1 in the absence and presence of phosphate anion, respectively.

Adsorption and recovery of uranium by nanoporous MCM-41 from aqueous solutions (synthetic solution and uranium conversion facility liquid waste) were investigated by use of a fixed-bed column (1.2 cm diameter and 3.0 cm height). Adsorption was carried out at flow rates 0.2 and 0.5 mL min−1, which correspond to retention times of 10 and 6 min. The maximum breakthrough capacity for uranium ions was achieved by use of nanoporous MCM-41 at the optimum pH of 3.6 and flow rate 0.2 mL min−1 (61.95 μg g−1). The Thomas and Yan models were applied to the experimental data, by use of linear regression, to determine the characteristics of the column for process design. The breakthrough curves calculated from the models were in good agreement with the experimental data. The elution behavior of uranium on nanoporous MCM-41 was studied with different eluents; the results showed that 0.1 M HCl is good eluent for uranium recovery. The regenerated column could be used in a multitude of adsorption–desorption cycles.

In this paper, the sorption of uranium onto nanoporous silica adsorbent in the presence of nitrate, sulfate, chloride, fluoride and phosphate was studied. The effect of contact time between the nanoporous sorbent and aqueous solution, pH and initial concentration of uranium was also investigated. Uranium sorption onto nanoporous silica adsorbent is a very fast process as sorption rate increases with pH increment. Optimum pH for uranium sorption was 4–8. Experimental sorption isotherm is successfully described by Langmuir and Freundlich models. The results obtained by batch experiments showed that the presence of high concentration of nitrate, sulfate, chloride and phosphate anions alone had no interference with uranium recovery. However, the presence of fluoride ions (>250 mg/L) decreases uranium sorption by about 55 %. The results also showed that the presence of phosphate ions (about 300 mg/L) in solution could remove fluoride interference completely. Finally, the efficiency of the nanoporous silica adsorbent for uranium recovery from wastewater of the uranium conversion facility was investigated.

Some new water-soluble Schiff-base complexes Na2[M(5-SO3-2,3-salpyr)(H2O) n ] · 2H2O (5-SO3-2,3-salpyr = N,N′-bis(5-sulphosalicyliden)-2,3-diaminopyridine and M = Zn, Cu, Ni) were synthesized and characterized by elemental analysis, IR, 1H NMR, magnetic susceptibility measurement, thermal analysis, and UV-Vis spectroscopy. The mechanism of binding of Na2[M(5-SO3-2,3-salpyr)(H2O) n ] · 2H2O with bovine serum albumin (BSA) was investigated by fluorescence spectroscopy. The fluorescence titration revealed that the intrinsic fluorescence of BSA was quenched by Na2[M(5-SO3-2,3-salpyr)], which was rationalized in terms of the static quenching mechanism. The values of the Stern–Volmer constants, quenching rate constants, binding constants, binding sites, and average aggregation number of BSA were determined by this method. Thermodynamic parameters were calculated by the van’t Hoff equation. The data clearly indicate that the binding is entropy driven and enthalpically disfavored. Based on the Forster theory of n...

In this study, some cobalt(II)tetraaza Schiff base complexes were used as donors in coordinating to triphenyltin(IV)chloride as acceptors; the kinetics and mechanism of the adduct formation were studied spectrophotometrically. Co(II)tetraaza Schiff base complexes used were [Co(amaen)][N,N′-ethylene-bis-(o-amino-α-methylbenzylideneiminato)cobalt(II)] (1), [Co(appn)] [N,N′-1,2-propylene-bis-(o-amino-α-phenylbenzylideneiminato)cobalt(II)] (2), [Co(ampen)] [N,N′-ethylene-bis-(o-amino-α-phenylbenzylideneiminato)cobalt-(II)] (3), [Co(cappn)][N,N′-1,2-proylene-bis-(5-chloro-o-amino-α-phenylbenzylideneiminato)cobalt(II)] (4), and [Co(campen)] [N,N′-ethylene-bis-(5-chloro-o-amino-α-phenylbenzylid-eneiminato)cobalt(II)] (5). The reactivity trend of the complexes in interaction with triphenyltin(IV)chloride was Co(amaen) > Co(appn) > Co(ampen) > Co(cappn) > Co(campen). The linear plots of kobs versus the molar concentration of the triphenyltin(IV)chloride, a high span of the second-order rate constant k2 values, and large negative values of ΔS≠ and low ΔH≠ values suggest an associative (A) mechanism for the acceptor–donor adduct formation. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 635–640, 2012

In the current study, two binuclear Pt (II) complexes, containing cis, cis-[Me2Pt (μ-NN) (μ-dppm) PtMe2] (1), and cis,cis-[Me2Pt(μ-NN)(μ dppm) Pt((CH2)4)] (2) in which NN=phthalazine and dppm=bis (diphenylphosphino) methane were evaluated for their anticancer activities and DNA/purine nucleotide binding properties. These Pt (II) complexes, with the non-classical structures, demonstrated a significant anticancer activity against Jurkat and MCF-7 cancer cell lines. The results of ethidium bromide/acridine orange staining and Caspase-III activity suggest that these complexes were capable to stimulate an apoptotic mechanism of cell death in the cancer cells. Using different biophysical techniques and docking simulation analysis, we indicated that these complexes were also capable to interact efficiently with DNA via a non-intercalative mechanism. According to our results, substitution of cyclopentane (in complex 2) with two methyl groups (in complex 1) results in significant improvement of the complex ability to interact with DNA and subsequently to induce the anticancer activity. Overall, these binuclear Pt (II) complexes are promising group of the non-classical potential anticancer agents which can be considered as molecular templates in designing of highly efficient platinum anticancer drugs.

The kinetics and mechanism of the adduct formation of diorganotin(IV)dichlorides (R2SnCl2), where R = Ph, Me, Bu, with Co(II) tetraaza Schiff base complexes such as: [Co(appn)][N,N′-1,2-propylenebis(o-amino-α-phenylbenzylideneiminato) cobalt(II)] and [Co(cappn)]{[N,N′-1,2-proylenebis(5-chloro-o-amino-α-phenylbenzylideneiminato)cobalt(II)]}, were studied spectrophotometrically. The kinetic parameters and the rate constant values show the acceptor tendency trend for the diorganotin(IV)dichlorides as follows: Ph2SnCl2 > Me2SnCl2 > Bu2SnCl2. Adducts were separately synthesized and fully characterized by 119Sn NMR, IR, UV-Vis spectra and elemental microanalysis (C.H.N) methods. The trend of the rate constants for the adduct formation of the cobalt complexes with a given tin acceptor decreased as follows: Co(appn) > Co(cappn). The linear plots of k obs vs. the molar concentration of the diorganotin(IV)dichlorides, the high span of the second order rate costant k 2 values and the large negative values of ΔS‡ suggest an associative (A) mechanism for the acceptor-donor adduct formation.II Moreover, [Co(aptn)][N,N′-1,3-propylenebis-(o-amino-α-phenylbenzylideneiminato)cobalt(II)] and [Co(captn)][N,N′-1,3- proylenebis-(5-chloro-o-amino-αphenylbenzylideneiminato)cobalt(II)] were synthesized and characterized but, their kinetics with R2SnCl2 were so fast that it was impossible to follow them using the conventional methods.

In this article the kinetics of the interaction between the teteraaza Schiff bases as donor with organotin(IV)chlorides as acceptor was studied in acetonitrile. Teteraaza Schiff bases are (Me4-Bzo2[14]tetraeneN4) (tmtaa), (Me4-4-CH3Bzo2[14]tetraeneN4) (Metmtaa), (Me4-4-ClBzo2[14]tetraeneN4) (Cltmtaa), i.e., [(Me4-Bzo2[14]tetraeneN4)] means that (5,7,12,14-tetramethyldibenzo[b,i][1,4,8,11] tetraazacyclotetradecine) (tmtaa) and organotin(IV)chlorides are methyltin(IV) trichloride, phenyltin(IV)trichloride, dimethyltin (IV)dichloride, diphenyltin(IV) dichloride, and dibutyltin(IV)dichloride. The kinetic parameters and the second-order k2 rate constants show the donor properties of tetraaza Schiff bases as Me4-4-CH3Bzo2[14]tetraeneN4 > Me4-Bzo2[14]tetraeneN4 > Me4-4-ClBzo2[14]tetraeneN4 and also the acceptor properties of organotin(IV)chlorides as PhSnCl3 > MeSnCl3 > Ph2SnCl2 > Me2SnCl2 > Bu2SnCl2. An excellent linearity of kobs vs. the molar concentration of the acceptor, the high span of k2 values, the large negative values of ΔS≠, and the low ΔH≠ values suggest an associative (A) mechanism for the acceptor–donor interaction. © 2011 Wiley Peiodicals, Inc. Int J Chem Kinet 43: 247–254, 2011

This article reports the synthesis and characterization of some new vanadyl Schiff base complexes, ((N-salicylideneN′-pyrrolidene)-1,2-ethylenediaminato)oxovanadium(IV) [VO (Salpyren)], ((7-methyl-N-salicylidene-N′-pyrrolidene)-1,2-ethylenediaminato) oxovanadium(IV) [VO(Mesalpyren)], ((7-phenylN-salicylidene-N′-pyrrolidene)-1,2-ethylenediaminato) oxovanadium(IV) [VO(Phsalpyren)], ((N-salicylidene-N′-pyrrolidene)-1,3propylenediaminato)oxovanadium(IV) [VO(Salpyrpd)], ((7methyl-N-salicylidene-N′-pyrrolidene)-1,3-propylenediaminato) oxovanadium(IV) [VO(Mesalpyrpd)], ((7-phenyl-N-salicylidene-N′-pyrrolidene)-1,3-propylenediaminato)oxovanadium(IV) [VO (Phsalpyrpd)]. These complexes were characterized by elemental analyses, IR, UV-Vis, and mass spectra. The kinetics and mechanism of the complex formation in methanol were studied spectrophotometrically. The second order k2 rate constants show the following trend: Mesalpyren > Salpyren > Phsalpyren > Mesalpyrpd > Salpyrpd > Phsalpyrpd The linear plots of kobs vs. ...

The kinetics and mechanism of the adduct formation of diorganotin(IV)dichlorides with Co(II) tetraaza Schiff base complexes, such as [Co(ampen)] {[N,N′-ethylenebis-(o-amino-α-phenylbenzylideneiminato)cobalt(II)]}, [Co(campen)] {[N,N′-ethylenebis-(5-chloro-o-amino-α-phenylbenzylideneiminato)cobalt(II)]}, and [Co(amaen)] {[N,N′-ethylenebis-(o-amino-α-methylbenzylideneiminato)cobalt(II)]}, were studied spectrophotometrically. The kinetic parameters and the rate constant values show the following acceptor tendency trend for the diorganotin(IV)dichlorides: Ph2SnCl2> Me2SnCl2> Bu2SnCl2. Adducts have been separately synthesized and fully characterized by 119SnNMR, IR, UV–vis spectra, and elemental microanalysis (C,H,N) methods. The trend of the rate constants for the adduct formation of the cobalt complexes with a given tin acceptor decreases as follow: Co(amaen) > Co(ampen) > Co(campen). The linear plots of kobs vs. the molar concentration of the diorganotin(IV)dichlorides, the high span of the second-order rate constant k2 values, and the large negative values of AS≠ suggest an associative (A) mechanism for the acceptor–donor adduct formation. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 499–507, 2010

Some new unsymmetrical tetradentate Schiff-base ligands, (N-salicylidene-N′-pyrrolidene)-1,2-ethylenediamine(H2salpyren) (H2L1), (H2Mesalpyren) (H2L2), (H2phsalpyren) (H2L3), (N-salicylidene-N′-pyrrolidene)-1,3-propylenediamine (H2salpyrpd) (H2L4), (H2Mesalpyrpd) (H2L5), (H2phsalpyrpd) (H2L6) and their Ni(II) and Cu(II) complexes were synthesized and characterized by elemental analyses, IR, UV-Vis, 1H NMR and mass spectra and magnetic moments. Possible structures of these complexes have been proposed. The thermodynamic formation constants of the complexes were determined spectrophotometrically at constant ionic strength 0.1 M (NaClO4), at 25°C in methanol.

The [Co(salpyren)PBu3]ClO4 · H2O, [(N-salicylidene-N′-pyrrolidene)-1,2-ethylenediaminato] tributylphosphineCo(III)perchlorate · monohydrate; [Co(Mesalpyren)PBu3]ClO4 · H2O, [(7-methyl-N-salicylidene-N′-pyrrolidene)-1,2-ethylenediaminato] tributylphosphineCo(III)perchlorate · monohydrate; [Co(Phsalpyren)PBu3]ClO4 · H2O [(7-phenyl-N-salicylidene-N′-pyrrolidene)-1,2-ethylenediaminato] tributylphosphineCo(III) perchlorate · monohydrate, were synthesized and characterized. The equilibrium constants and the thermodynamic parameters were measured spectrophotometrically for the 1:1 adduct formation of [Co(chel)PBu3]ClO4 · H2O, where (chel = salpyren, Mesalpyren, Phsalpyren) as acceptors with phosphites [P(OR)3 (R = Me, Et and i-Pr)] as donors, in acetonitrile (CH3CN) and dimethylformamide (DMF) solvents, in constant ionic strength (I = 0.1 m NaClO4) and at various temperatures T = 283 to 313 K. The trend of the equilibrium constants of the donors (phosphites) toward a given cobalt(III) Schiff base complex is as follows: P(OEt)3 > P(Oi-Pr)3 > P(OMe)3. The trend of the equilibrium constants of the cobalt(III) Schiff base complexes toward a given phosphite is as follows: 7-Mesalpyren > salpyren > 7-Phsalpyren. The trend of the equilibrium constants with a given donor toward a given acceptor with respect to the solvent is as follows: CH3CN > DMF.

The kinetics and mechanism of the adduct formation of two Co(II) tetraaza complexes, [Co(ampen)] {[(N,N′-ethylenebis-(o-amino-α-phenylbenzylideneiminato)cobalt(II)]} and [Co(campen)] {[(N,N′-ethylenebis-(5-chloro-o-amino-α-phenylbenzylideneiminato)cobalt(II)]}, with four organic bases, 4-nitro imidazole (4-NO2Imid), 4-methyl imidazole (4-MeImid), imidazole (Imid), and 1-methyl imidazole (1-MeImid), in DMF were studied spectrophotometrically. The kinetic parameters and the second-order k2 rate constants show the following nucleophilicity trend of the bases toward the given substrate: 4-NO2Imid > 4-MeImid > Imid > 1-MeImid. The linear plots of kobs vs. the molar concentration of the base, the high span of k2 values, and the large negative values of ΔS≠ suggest an associative (A) mechanism. © 2007 Wiley Periodicals, Inc. 39: 137–144, 2007

A newly synthesized nano tetraimine Pd(0) complex (PTIC) is used as an efficient catalyst in Heck—Mizoroki reactions to afford a series of (het)aryl alkenes.

Background Failure of endodontic treatment is usually due to an inadequate disinfection of the root canal system. Enterococcus faecalis has been widely used as a valuable microbiological marker for in-vitro studies because of its ability to colonize in a biofilm like style in root canals, invading dentinal tubules and resistance to some endodontic treatments. The aim of this study was to investigate the antibacterial effects of two methods of photodynamic therapy using a light emitting diode lamp (LED lamp, 630 nm) and a diode laser (810 nm) on E. faecalis biofilms in anterior extracted human teeth. Methods Fifty six single-rooted extracted teeth were used in this study. After routine root canal cleansing, shaping and sterilization, the teeth were incubated with E. faecalis for a period of two weeks. Teeth were then divided into two experimental groups (nu = 23) and two control groups (nu = 5). Teeth in one experimental group were exposed to a diode laser (810 nm), and in the other group samples were exposed to a LED lamp (630 nm). Intracanal bacterial sampling was done, and bacterial survival rate was then evaluated for each group. Results The Colony Forming Unit (CFU) in LED group (log 10 CFUs = 4.88 ± 0.82) was significantly lower than the laser group (log CFUs = 5.49 ± 0.71) ( p value = 0.021). CFUs in positive control group (Log 10 CFUs = 10.96 ± 0.44) were significantly higher than the treatment group ( p ˂ 0.001). No bacterial colony was found in negative control group. Conclusion The results of this research show that photodynamic therapy could be an effective supplement in root canal disinfection. PDT using LED lamp was more effective than diode laser 810 nm in reducing CFUs of E. faecalis in human teeth.

The complexes: [Co(BAE)(PEt3)]ClO4 · H2O(BAE=bis(acetylacetone)ethylenediimine) and [Co(BBE)(PR3)]ClO4 · H2O, (BBE=bis(benzoylacetone)ethylenediimine and R=Et, Bu), were synthesized and characterized. The equilibrium constants and the thermodynamic parameters were measured spectrophotometrically for 1∶1 adduct formation of [Co(chel)L]ClO4 · H2O, (where chel=BAE, BBE and L=PBu3, PEt3 and PMe2Ph) as acceptors and P(OR)3 (R=Me, Et and Ipr) as donors, in acetonitrile in constant ionic strength (I=0.01M Et4NClO4) and at various temperatures T=293 to 313 K. The trend of the equilibrium constants of five coordinate cobalt(III) Schiff base complexes toward a given phosphite donor according to the axial ligand is as follows: PMe2Ph>PBu3≈PEt3. Also, the trend of the equilibrium constants of the donors (phosphite) toward a given cobalt(III) Schiff base complex is as follows: P(OEt)3>P(OIpr)3>P(OMe)3. The trend of the equilibrium constants of cobalt(III) Schiff base complexes with respect to the Schiff bases used in ...

The [Co(acacen)(PMe2Ph)]ClO4 · H2O (acacen=bis(acetylacetone)ethylene diimine) was synthesized and characterized. The equilibrium constants and the thermodynamic parameters were measured spectrophotometrically for 1:1 adduct formation of [Co(acacen)L]ClO4 · H2O, where (L=PBu3, PMe2Ph) as acceptors with H2NR (R=n-propyl, n-butyl, sec-butyl) as donors, in ethanol and butanol solvents in constant ionic strength (I=0.01 M NaClO4) and at various temperatures T=(288 to 308) K. The trend of the reactivity of five-coordinate cobalt(III) Schiff base complexes toward a given amine donor according to the axial ligand is as follow: PMe2Ph > PBu3. Also the trend of the reactivity of the donors (amines) toward a given cobalt(III) Schiff base complex is as follow: n-propylamine > n-butylamine > sec-butylamine. The trend of the reactivity of a given cobalt(III) Schiff base complexes toward a given amine donor according to the solvent is as follow: butanol > ethanol.

Chemistry Department, College of Sciences, Shiraz University, Shiraz, I.R. Iran E-mail : zasadi@susc.ac.ir, zasadi@shirazu.ac.ir Fax : 98-711-2286008 Manuscript received online 15 October 2013, revised 17 October 2013, accepted 24 October 2013 This article presents σ-acceptor strength for the diorganotin(IV)dichlorides : dimethyltindichloride, diphenyltindichloride and dibutyltindichloride as Lewis acids toward some macrocyclic nickel(II) complexes. Thermodynamic of the adducts formation of the tin(IV)dichlorides with Ni(II)tetraaza Schiff base complexes such as : [Ni(Me4 -Bzo2 [14]- tetraeneN4 )], [Ni(Me4 -4-CH3Bzo2 [14]tetraeneN4 )], [Ni(Me4 -4-ClBzo2 [14]tetraeneN4 )] and [Ni(Me2Ph2 -Bzo2 [14]tetraeneN4 )], [Ni(Me2Ph2 -4-CH3Bzo2 [14]tetraeneN4 )], [Ni(Me2Ph2 -4-ClBzo2 [14]tetraeneN4 )] that Me4 -Bzo2 [14]tetraeneN4 denotes : (5,7,12,14-tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclo-tetradecine), was studied in acetonitrile by means of UV-Vis spectrophotometric analysis. The thermodynamic parameters and the formation constant values show the acidity trend for diorganotin(IV)dichlorides as follow : Ph2 SnCl2 > Me2 SnCl2 > Bu2 SnCl2 . Adducts have been synthesized and fully characterized by 1H NMR, 119Sn NMR, IR, UV-Vis spectra and elemental microanalysis (C.H.N) methods. The trend of the adduct formation of the nickel complexes with a given tin acceptor decrease as follow : [Ni(Me4 -4- CH3Bzo2 [14]tetraeneN4 )] > [Ni(Me4 -Bzo2 [14]tetraeneN4 )] > [Ni(Me4 -4-ClBzo2 [14]tetraeneN4 )] > [Ni(Me2Ph2 -4- CH3Bzo2 [14]tetraeneN4 )] > [Ni(Me2Ph2 -Bzo2 [14]tetraeneN4 )] > [Ni(Me2Ph2 -4-ClBzo2 [14]tetraeneN4 )].

Metal Schiff-base complexes show biological activity but they are usually insoluble in water so four new water-soluble metal Schiff base complexes of Na2[M(5-SO3-1,2-salben]; (5-SO3-1,2-salben denoted N,N'-bis(5-sulphosalicyliden)-1,2-diaminobenzylamine and M=Mg, Mn, Cu, Zn) were synthesized and characterized. The formation constants of the metal complexes were determined by UV-Vis absorption spectroscopy. The interaction of these complexes with bovine serum albumin (BSA) was studied by fluorescence spectroscopy. Type of quenching, binding constants, number of binding sites and binding stoichiometries were determined by fluorescence quenching method. The results showed that the mentioned complexes strongly bound to BSA. Thermodynamic parameters indicated that hydrophobic association was the major binding force and that the interaction was entropy driven and enthalpically disfavoured. The displacement experiment showed that these complexes could bind to the subdomain IIA (site I) of albumin. Furthermore the synchronous fluorescence spectra showed that the microenvironment of the tryptophan residues was not apparently changed. Based on the Forster theory of non-radiation energy transfer, the distance between the donor (Trp residues) and the acceptor metal complexes was obtained. The growth inhibitory effect of complexes toward the K562 cancer cell line was measured.

Background Immunofluorescence antigen mapping (IFM), is a newly introduced technique for diagnosis and classification of epidermolysis bullosa (EB) disease. The precise level of skin cleavage can be determined using monoclonal antibodies to EB-specific basement membrane zone protein. Objective To apply IFM technique in diagnosis and classification of EB and to identify utility and limitation of this method in our clinical setting. Methods IFM was done according to a described protocol by Pohla-Gubo et al. Monoclonal antibodies used for antigen mapping were against cytokeratin 5, cytokeratin 14, α6 integrin, β4 integrin, laminin 332, Collagen IV, and Collagen VII. Results IFM was done for 95 referred patients, compromising 49 females and 46 males, aged 5 days to 45 years (mean = 9.5 years). Ninety cases were diagnosed with EB and classified as follows: EB simplex: (n = 13), junctional EB (n = 14), dystrophic EB (n = 62), and Kindler syndrome (n = 1). Diagnosis was not made in five cases as their specimens contained no blister. Confirmatory genetic analysis was done for five junctional cases from two families with clinical features of laryngo-onycho-cutaneous syndrome. Genetic molecular studies showed nonsense mutations in the last codon of exon 39 of the laminin α3a (LAMA3) gene (p.Gln57X) and a donor splice site mutation in LAMA3 (IVS57+5G>A) in the first and second family, respectively. Conclusion IFM technique is relatively simple to perform, and interpretation of the results is not sophisticated. The proportion of inconclusive results will be decreased if the specimens contain freshly induced blister.

Some new water-soluble Schiff base complexes of Na 2 [M(L)(H 2 O) n ]; (M = Zn, Cu, Ni, Mn) with a new water-soluble Schiff base ligand where L denotes an asymmetric N 2 O 2 Schiff base ligands; N,N′-bis(5-sulfosalicyliden)-3,4-diaminobenzophenone (5-SO 3 -3,4-salbenz) were synthesized and characterized. The formation constants of the water soluble Schiff base complexes were calculated by Ketelaar’s equation. The theoretical molecular structure for the complexes was computed by using the HF method and the 6-311G basis set. The mechanism of binding of Na 2 [M(L)(H 2 O) n ] with human serum albumin (HSA) was studied by fluorescence spectroscopic technique. The results of fluorescence titration showed that the intrinsic fluorescence of HSA was quenched by the complexes; which was rationalized in terms of the dynamic quenching mechanism. The values of Stern–Volmer constants, quenching rate constants, binding constants, binding sites and average aggregation number of HSA have been determined. The thermodynamic parameters, were calculated by van’t Hoff equation, indicate that the binding is entropy driven and enthalpically disfavored. Based on the Forster theory of non-radiation energy transfer, the efficiency of energy transfer and the distance between the donor (Trp residues) and the acceptor (complex) were obtained. Finally, the growth inhibitory effects of the complexes toward the K562 cancer cell line were measured.

Summary Laryngo-onycho-cutaneous (LOC) syndrome is a subtype of autosomal recessive junctional epidermolysis bullosa in which there is prominent skin and mucosal granulation tissue that can lead to delayed wound healing, laryngeal obstruction and blindness. Thus far, all cases are of Punjabi ancestry and have been shown to result from a founder mutation in the LAMA3 gene, notably involving a single nucleotide insertion mutation in exon 39, which is specific to the LAMA3A (designated exon 1 of LAMA3A) and not the LAMA3B1 or LAMA3B2 isoforms. Here, we describe a new pedigree with LOC syndrome. Affected individuals (from Iran) have the characteristic clinicopathological and molecular features of LOC syndrome: prominent granulation tissue (especially affecting the eyes), normal intensity laminin-332 immunostaining at the dermal–epidermal junction, and autosomal recessive mutations in the LAMA3A-specific exon. The pathogenic mutation is a homozygous nonsense mutation, designated p.Gln57X, which just affects the laminin-α3a transcript. These findings therefore expand the molecular basis of LOC syndrome.

Service providing by customers’ preserving and satisfaction is one of the basic tools of service organizations survival in today’s competitive environment. The high-contact service is not an exception of this principle. One of the fields which can be used remarkably in order to preserve and satisfy the customer in these kinds of service is the service friendship between the service provider and the customers. In the present study, the relationship among the customers’ Personality traits, communicational skills of the high-contact service providers, and the service friendship has been investigated. The sample of the study includes 345 customers of counseling and medical service of Isfahan which 191 were females, and 154 were males. The effect of the extroversion variables and sociability on the communicational skills and communicational skills effects on the friendship service, and also the effect of the friendship service on the satisfaction and anticipation of future interaction have been investigated. The data analysis has been done using Lisrel 8.5. The results indicate that the extroversion variables have affected the communicational skills, the communicational skills affected the friendship service, friendship service affected the satisfaction, and satisfaction affected the anticipation of the future interaction in a significant positive way. However, the significance effect of the sociability on the communicational skills and the friendship service effects on the anticipation of the future interaction have been rejected.

Retinopathy of prematurity (ROP) is a multifactorial disease, that cause visual impairment in premature children. The exact pathogenesis and etiology of ROP is unknown and genetic susceptibility is considered as risk factor. Vascular endothelial growth factor (VEGF) plays a major role in retinal neovascularization and subsequently retinal detachment. VEGF polymorphism is associated with proliferative ROP in some studies. We examined the possible association of the VEGF gene polymorphisms with ROP in preterm infants in south of Iran. A total of 111 preterm infants were examined by ophthalmologist and after that were genotyped. Genotyping of the VEGF +405 (rs2010963) and VEGF +936 (rs3025039) was done by the polymerase chain reaction and restriction fragment length polymorphism methods. The frequency of VEGF alleles, genotypes and haplotype distribution were compared between groups. The patients were divided in three groups: 66 to the normal group (normal fundoscopy), and 45 to the ROP group; 30 infants were not treated with Lasertherapy (Regressive group) and 15 treated with Lasertherapy. The frequency of VEGF +405 and VEGF +936 G/C genotypes as well as allele frequencies was not different between groups. No significant difference was found between ROP with treatment and ROP without lasertherapy. Our report indicate that there is no association between the carrier states of gene polymorphisms VEGF +405, VEGF +936 and progression or spontaneous regression of ROP in preterm infants in Iranian population. However, it should be considered that angiogenesis is a complex process and genetic factors in addition to environmental factors are contributed in this pathway.

Some tetradentate salen type Schiff bases and their uranyl complexes were synthesized and characterized by UV–Vis, NMR, IR, TG, C.H.N. and X-ray crystallographic studies. From these investigations it is confirmed that a solvent molecule occupied the fifth position of the equatorial plane of the distorted pentagonal bipyramidal structure. Also, the kinetics of complex decomposition by using thermo gravimetric methods (TG) was studied. The thermal decomposition reactions are first order for the studied complexes. To examine the properties of uranyl complexes according to the substitutional groups, we have carried out the electrochemical studies. The electrochemical reactions of uranyl Schiff base complexes in acetonitrile were reversible.

Four new complexes, [M(Salpyr)] where Salpyr = N,N′-bis(Salicylidene)-2,3- and 3,4-diiminopyridine and M = Co, Cu, Mn, Ni and Zn were synthesized and characterized by 1 H NMR, IR spectroscopy, elemental analysis and UV–vis spectrophotometry. UV–vis spectrophotometric study of the adduct formation of the zinc(II) complexes, [Zn(2,3-Salpyr)] and [Zn(3,4-Salpyr)], as donor with R 2 SnCl 2 (R = methyl, phenyl, n-butyl), PhSnCl 3 and Bu 3 SnCl as acceptors has been investigated in methanol, as solvent. The formation constants and the thermodynamic free energies were measured using UV–vis spectrophotometry. Titration of the organotin chlorides with Zn(II) complexes at various temperatures ( T = 283–313 K) leads to 1:1 adduct formation. The results show that the formation constants were decreased by increasing the temperature. The trend of the reaction of R n SnCl 4− n as acceptors toward given zinc complexes was as follows: PhSnCl 3 > Me 2 SnCl 2 > Ph 2 SnCl 2 > Bu 2 SnCl 2 > Bu 3 SnCl By considering the formation constants and the Δ G ° of the complex formation for the Schiff base as donor and the M(II) as acceptor, the following conclusion was drawn: the formation constant for a given Schiff base changes according to the following trend: Ni > Cu > Co > Zn > Mn

We report a case of a 31-year-old man with asymptomatic papules on one side of his face that had been present for 31 months. On physical examination, he had clusters of 1 to 4 mm skin colored translucent and dome-shaped, papules forming a plaque with a size of 4 x 3 cm on his left mandibular angle. Histopathology revealed atrophy of the epidermis with extensive deposition of pale eosinophilic homogenous deposits containing artifactual fissures that were PAS positive, diastase resistant, and Congo red negative. The final diagnosis was unilateral colloid milium.

Granuloma faciale (GF) is a rare cutaneous disorder categorized as a localized form of small vessel vasculitis. Clinically, it manifests as single or multiple, well-demarcated, red-brown plaques, papules and nodules, nearly always confined to the face. Herein, we report a 39-year-old man with multiple red-brown, infiltrated plaques on his face and extrafacial lesions on the back, shoulders, and both arms. Skin biopsy revealed typical histopathological findings of GF. The patient failed to respond to pulsed dye laser, but intralesional triamcinolone combined with cryotherapy led to an acceptable response.

Tramadol, as a centrally-acting, opioid-like analgesic with serotonin reuptake inhibition property, is one of the most prescribed analgesics in the world. We assessed the incidence of seizure, as it is one of the most important adverse effects.In a cross-sectional study, 215 cases of tramadol users or abusers who were admitted to Loghman-Hakim Hospital Poisoning Center (LHHPC) in Tehran during a 5-month period, from April 2007 to September 2007, were assessed to evaluate the occurrence of seizure. Patients with positive history of co-ingestion of other drugs, addiction, convulsive disorders, renal diseases, or head trauma with abnormal electroencephalography (EEG) or computerized tomography (CT) scan of the brain were excluded, thus 132 patients were included in the study. For patients who had seizure, CT scan of the brain and EEG were performed, and frequency and type of seizure were identified. Mean tramadol dose was compared between patients with and without seizure.Among the patients, 97 (73.5%) were male. Seizure occurred in 61 patients (46.2%) within 24 hours after tramadol ingestion. The majority of patients who had seizure were male (male, 83.6% vs. female, 16.4%). Mean tramadol dose was lower among females than males (males, 2413 mg vs. females, 1706 mg), but the difference was not statistically significant. Of 35 patients with documented seizure type, all showed generalized tonic-clonic seizure and 12 patients had abnormal EEG (35.3%). No statistically significant difference was observed in mean tramadol intake between patients with or without seizure. Analysis of patients with seizure, according to tramadol intake, indicated that most patients used tramadol in the dose range of 500-1000 mg followed in occurrence by 1500-2000 mg, then 100-500 mg, 2500-3000 mg, and 3500-4000 mg.Mean tramadol intake does not differ between patients with and without seizure, and the most common dose range in those with seizure is 500-1000 mg. We thus conclude that the incidence of seizure with tramadol is not dose dependent.

Epidermodysplasia verruciformis (EV) is a rare genodermatosis associated with a high risk of skin cancer. In this report, we present three Iranian brothers and their mother with extensive seborrheic keratosis-like (SK-like) viral warts. Initial facial lesions developed in the first decade and disseminated with time. The patients showed SK-like viral warts characterized by dark brown or black pigmented proliferative lesions with hyperkeratotic surfaces. The histopathological findings were consistent with the diagnosis of EV. There are few reports of familial epidermodysplasia verruciformis especially in a mother and her three sons.

Kaposi′s sarcoma (KS) is a malignant proliferation of the endothelial cells. It typically presents with several vascular nodules on the skin and other organs. The penile localization of KS, particularly on the shaft area, is exceptional. We report an HIV-positive 34-year-old man who had multiple purplish-black plaques on his extremities and several small violaceous macules on the glans and shaft of the penis. Kaposi′s sarcoma was diagnosed by histopathology.