Some new schiff bases, (Z)-4-amino-3-((E)-(R-methoxybenzylidene) hydrazono)-6-methyl-3,4-dihydro-1, 2, 4-triazin-5 (2H)-one (R=2 (L2), R=3 (L3) and R=4 (L4)), were synthesized by the condensation reactions of 4-amino-3-hydrazinyl-6-methyl-1,2,4-triazin-5(4H)-one (L1) and corresponding methoxybenzaldehyde in a molar ratio 1:1.5 in high yields. The reaction of L2 and L4 with an excess amount of the corresponding aldehydes gave the unsymmetrical bis-schiff bases (E)-3-((E)-(R-methoxybenzylidene)hydrazono)-4-((E)-R-methoxybenzylideneamino)-6-methyl-3,4-dihydro-1,2,4-triazin-5(2H)-one (R=2 (L22) and R=4 (L44)), respectively. Furthermore, the reaction of L2–L4 with silver(I) nitrate in a molar ratio 2:1 led to the silver(I)-complexes with the general formula [Ag(Lx)2]NO3 (Lx=L2 (2), L3 (3) and L4 (4)). All synthesized schiff base compounds and complexes were characterized by a combination of IR-, 1H-NMR spectroscopy, mass spectrometry and elemental analyses. In addition, the structures of L2, L4.CH3CN, L22.CH3OH and L44.CH3OH and complexes 2 and 4 were determined by X-ray diffraction studies.

The formation constants and Gibbs free energy for the interaction of Rn SnClm (n=m=2, R= Me, Ph, n-Bu or n=4, m=0, R=Ph) compounds as acceptors, with ML complexes (H2L =N, N' -bis (salicylidene) -2-aminobenzylamine (salabza-H2) and its derivatives, M=Mn2+ or Zn2+), as donors in N, N' -dimethylformamide (DMF) as solvent were studied. These parameters were measured by using UV-vis spectrophotomety titration for 1: 1 adduct formation of the selected complexes at 25 (±0.1)oC in the 200-500 nm regions. The trend of adduct formation constants between metal schiff base complexes as donors and tin (IV) as acceptor decreases as follow:Me2 SnCl2>Ph2 SnCl2>n -Bu2 SnCl2>Ph4 Sn [M (5-OMe-salabza)]>[M (salabza)]>[M (5-Br-salabza)]>[M (5-NO2 -salabza)] Zn>Mn

The effects of 2, 2'- [bis-N (4-cholorobenzaldimin)] -1, 1'-dithio (BCBD) and bis- (2-aminophenyl) disulphide (BAPD) on the corrosion behavior of 302 stainless steel in 0.5 M sulfuric acid solution as corrosive medium were investigated using weight loss and potentiostatic polarization techniques. Some corrosion parameters such as anodic and cathodic Tafel slopes, corrosion potential, corrosion current density, surface coverage degrees and inhibition efficiencies were calculated. The polarization measurements indicated that the inhibitors were of mixed type which inhibited corrosion by parallel adsorption on the surface of stainless steel due to the presence of more than one active centre in the inhibitor molecule. The adsorption followed Langmuir adsorption isotherm. The activation energy and thermodynamic parameters were calculated at different temperatures. Results showed that BCBD had a higher inhibition efficiency compared with BAPD.

Chitosan is the product of N-deacetylation of chitin. For its innocuous, renewable, biocompatible property chitosan is applied in many fields e. g., pharmaceutical, food, catalysis, material. In this work, three chitosan-based schiff-based (CSB) compounds with aromatic substituent groups were synthesized from the reaction of chitosan with different aromatic aldehydes i.e., salicylaldehyde, 4-hexadecyloxy-2- hydroxybenzaldehyde and 2-hydroxy-1-naphthaldehyde. The chitosan-based schiff base copper (II) complexes (CSBCu) were subsequently obtained through the reaction of relative schiff bases with copper acetate. These products were characterized by elementary analysis (EA), Fourier transform infrared (FTIR) spectroscopy, thermal analysis (TG-DSC, TG-DTA), and X-ray diffraction (XRD) spectra, respectively. Generally, elemental analysis data may confirm the formation of chitosan-schiff base as well as the coordination reaction of CSB with copper ions. FTIR analysis indicated that schiff base and coordination reaction take place in schiff base skeleton. Moreover, with the difference in substituent groups and spacer, FTIR spectra showed the clear variety. Thermal analysis showed that the thermal stability of CSB increased slightly, while that of the copper complexes was reduced significantly in comparison with chitosan. The XRD results demonstrated the appearance of a new crystallization peak of CSB in the vicinity of five degree and the lower crystallinity of CSBCu. The differences in crystallinity and thermal stability are mainly attributed to the formation of schiff base group and complexation with copper ions, as well as spatially partial hindrance and hydrophobic forces in the aromatic substituent groups. The present results show that the specific properties of chitosan-based schiff base derivatives can be altered by modifying the molecular structures of objective compounds with proper substituent groups.

mononuclear copper (II) complexes of 1, 2, 4-triazole-based schiff base macrocyclic hydrazones, III and IV, have been reported. The prepared amorphous complexes have been characterized by spectroscopic methods, electron spray ionization mass spectrometry, and elemental analysis data. Electrochemical studies of the complexes in DMSO show only one quasi-reversible reduction wave at +0.43 V (DE = 70 mV) and +0.42 V (DE = 310 mV) for III and IV, respectively, which is assigned to the Cu (II) ® Cu (I) reduction process. Temperature dependence of magnetic susceptibilities of III and IV has been measured within an interval of 2-290 K. The values of cM at 290 K are 1.72 × 10-3 cm3 mol-1 and 1.71 ´ 10-3 for III and IV, respectively, which increases continuously upon cooling to 2 K. EPR spectra of III and IV in frozen DMSO and DMF were also reported. The trend g|| > g^ > ge suggests the presence of an unpaired electron in the dx2-y2 orbital of the Cu (II) in both complexes. Furthermore, spectral and antimicrobial properties of the prepared complexes were also investigated.