Mn2+-COMPLEXES OF N,O-DIHYDRAZONE: STRUCTURAL STUDIES, INDIRECT BAND GAP ENERGY AND CORROSION INHIBITION ON ALUMINUM IN ACIDIC MEDIUM
摘要:
Mononuclear manganese complexes of dihydrazone derived from the condensation of oxaloyldihydrazide with 2-hydroxynaphthaldehyde and 2-methoxybenzaldehyde have been synthesized. The hydrazone Schiff base ligands and their chelates were characterized on the basis of their elemental analyses. spectral (UV-Vis., IR, mass, H-1/C-13 NMR), magnetism, ESR and thermal (TGA) measurements. The dihydrazone has been suggested to coordinate to the metal center in bi-dentate manner forming 1:1[M:L] complex. The complexes are suggested to have tetrahedral/octahedral stereochemistry. Optical transmission spectra were recorded in the range 190-2100 nm and optical band gap energy was determined. The band gap energy (E-g) for all separated compounds lies in the range of semiconductors. On the other hand, the inhibition and adsorptive properties of the ligands for the corrosion of aluminum in 1 M HCl solutions were studied using traditional weight loss measurements. The results revealed that bis(2-methoxy-benzaldehyde)oxaloyldihydrazone has a greater inhibition than bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone. The adsorption of the inhibitors on metal surface was found to be spontaneous first order reaction and consistent well with the mechanism of physical adsorption. The adsorption data fitted well to Freundlich, Langmuir and Frumkin adsorption isotherms.
Physicochemical studies on some selected oxaloyldihydrazones and their novel palladium(II) complexes along with using oxaloyldihydrazones as corrosion resistants
作者:Ayman H. Ahmed、A. M. Hassan、Bassem H. Mohamed、Hosni A. Gumaa、Ahmed M. Eraky
DOI:10.1080/24701556.2017.1357595
日期:2017.12.2
New palladium (II) oxaloyldihydrazone complexes are reported and characterized. The mode of bonding as well as the structure of the isolated compounds have been ascertained on the basis of data obtained from elemental analyses (CHNM), spectral (UV-Vis., IR, mass and 1H NMR) and thermal (TG and DTA) measurements. Some optical parameters such as indirect optical band gap and refractive index were estimated
据报道和表征了新的钯(II)草酰二hydr配合物。已根据元素分析(CHNM),光谱(UV-Vis。,IR,质量和1 H NMR)和热(TG和DTA)获得的数据确定了键合模式以及分离的化合物的结构) 测量。对于分离出的化合物,估计了一些光学参数,例如间接光学带隙和折射率。测试了所有合成的在1 M HCl溶液中对碳钢腐蚀的抑制性能。steel抑制剂在钢表面的吸附过程是自发的一级反应。