The effect of the concentration of the colloidal nanomaterial on their optical limiting behavior is reported in this paper. The colloids of sliver nanoparticles in deionized water were chemically prepared for the two concentrations (31 ppm and 11ppm). Two cw lasers (473 nm Blue DPSS laser and 532 nm Nd:YAG laser) are used to compare the optical limiting performance for the samples. UV–visible spectrophotometer, transmission electron microscope (TEM) and Fourier Transformation Infrared Spectrometer (FTIR) were used to obtain the characteristics of the sample. The nonlinear refractive index was calculated to be in the order of 10-9 cm2/W. The results demonstrate that the observed limiting response is significant for 532nm. In addition, t

This work involves the preparation of the ligand [KL] :-                    Â­Â­Â­Â­Â­Â­

K[4-(N-(5-methylisoxazol-3-yl) sulfamyl) phenylcarbamodithioate] from the reaction of sulfamethoxazole  with Carbon disulfide  in the presence of  potassium hydroxide under reflux (4 hours) using methanol as asolvent. The prepared ligand was characterized using FT-IR, UV-Vis, ¹H,¹³C–NMR spectroscopy, molar conductivity and melting point,  Complexes for the above ligand [KL] with some bivalent transition and non-transition metals (Mn ⁺², Co⁺²  , Ni⁺²  ,

      The complexes of Pd+2 ion with 2-(5-bromo-2-pyridylazo)-5-dieıhyl aminophenol (BPADAP) were studied kinetically and spectrophotometrically in aqueous ethanolic solutions. The reagent forms 1:1, 2:1 square planer and 1:1 bridged shape binuclear complexes with Pd+2 ion. All these complexes (violet colour) absorb light in the same region at 540, 575 and 618nm. The band at 618 nm seems to be specific for complexes of Pd+2ion with BPADAP.   The rate constants of the growth in 93% H2O + 7% ethanol of 1:1 and 2:1 complexes at 575 and 618 nm were followed the first order kinetics and are quite of the same values , 0.495 and 0.463 min- 1  respectively. The rate constants of the decay of 2:1 complex

 The synthesis of complexes for (Ca+2, Co+2, Ni+2, Cu+2, Zn+2, Cd+2 and Hg+2) with new ligand (5-C-dimethyl malonyl-pentulose-γ-lactone-2,3-enedibenzoate) (L) have been successfully prepared and characterized by (1H and 13CNMR, FTIR, (U.V-Vis) spectroscopy, Atomic absorption spectrophotometer (A.A.s), Molar conductivity measurements and Magnetic moment measurements, and the following general formula has been given for the prepared complexes [M(L)Cl2] where M = (Ca+2, Co+2, Ni+2, Cu+2, Zn+2, Cd+2, Hg+2),  L = (5-C-dimethyl malonyl-pentulose-γ-lactone-2,3-enedibenzoate).

Nine new compounds of 2-amino-5-chlorobenzothiazole derivatives were synthesized. These new compounds were formed through the reaction of 2-amino-5-chlorobenzothiazole 1 with ethyl chloroacetate and KOH, which gave an ester derivative 2, followed by refluxing compound 2 with hydrazine hydrate to afford hydrazide derivative 3. The reaction of compound 3 with CS₂ and KOH gave 1,3,4-oxadiazole-2-thiol derivative 4, and then the reaction of compound 2 with thiosemicarbazide to produce compound 5  then treated it with 4%NaOH led to ring closure to provide 1,2,4-triazole-3-thiol derivative

 New complexes of cobalt (II). palladium (II). and platiniurn(H) with 5-phenyl- 1.3,4-oxadiazole-2- thioethylcarbanate (OXE) have been prepared and characterized by elemental analysis, 1R.L-V-Vis spectra. magnetic susceptipibility. and conductivity- measurements. Probable structures of the prepared complexes have been reported.

A new series of Fe (III) , Co (II) , Ni (II) and Cu (II) complexes of the Schiff base, 5 (2-hydroxy benzylidine) -2-thio ether -1, 3, 4-thiadiazole were prepared and characterized .The imine behaves as a bidentate. The nature of bonding and the stereochemistry of the complexes were deduced from metal analyses, infrared, electronic spectra,magnetic susceptibility and conductivity measurements, an octahedral geometry was suggested for all complexes except the copper complex has a square planar geometry .preliminary in vitro tests for antimicrobial activity show that all the prepared compounds except iron complex display good activity to gram positive Staphelococcus aures and gram negative Escherchia coli.

The plant occupied the largest area in the biosynthesis of silver nanoparticles, especially the medicinal plants, and it has shown great potential in biotechnology applications. In this study, green synthesis of silver nanoparticles from Moringa oleifera leaves extract and its antifungal and antitumor activities were investigated. The formation of silver nanoparticles was observed after 1 hour of preparation color changing. The ultraviolet and visible spectrum, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy techniques were used to characterize synthesis particles. Ultraviolet and visible spectroscopy showed a silver surface plasmon resonance band at 434