synthesized from nicotinic acid hydrazide and differently substituted benzaldehydes. The protonation constants of the 12 resulting hydrazones, as well as of the starting compounds, were determined in methanol/water 1/1 mixtures by spectrophotometric–potentiometric batch titrations. In order to determine the effect of substituents on the stability of the C=N bond, the kinetics of hydrolysis of hydrazones was
Antimicrobial Activities of Synthetic Arylidine Nicotinic and Isonicotinic Hydrazones
作者:Muhammad Hayat、Khalid Mohammed Khan、Sumayya Saeed、Uzma Salar、Momin Khan、Taimoor Baig、Aqeel Ahmad、Shahnaz Parveen、Muhammad Taha
DOI:10.2174/1570180814666170914120337
日期:2018.8.27
showed significant to moderate antimicrobial activities against Grampositive and Gramnegative bacterial cultures. Few compounds also showed antifungal activity against fungal cultures. Minimum Inhibitory Concentration (MIC) was calculated for the most active compounds 1, 7, 11, 19, 34, 46, 50, 51, and 55 against grampositive and gramnegative cultures. Conclusion: Newly identified compounds may serve
nitrogen and oxygen of the phenolic hydroxyl group were proposed as the coordination sites for the copper(II) ion. In all applied synthesis conditions Cu(II) complexes were obtained in Cu(II)/hydrazone molar ratio of 1/1, except for a hydrazone with nitro group, which did not form a complex with Cu(II) regardless of the synthetic conditions. Vibrational spectra indicated that hydrazone having only ortho-hydroxyl
摘要 利用红外(IR)和拉曼光谱分析了苯环上不同取代基的烟酸酰肼和水杨醛衍生物得到的芳酰腙固体铜配合物的结构。研究的芳香腙作为中性、单阴离子或双阴离子三齿配体,取决于络合过程中采用的互变异构体形式。水杨醛环上的各种附加取代基不参与金属配位,因此羰基/烯醇氧、偶氮甲碱氮和酚羟基的氧被提议作为铜(II)离子的配位位点。在所有应用的合成条件下,Cu(II)/腙摩尔比为 1/1 得到 Cu(II) 配合物,但带有硝基的腙除外,无论合成条件如何,它都不会与 Cu(II) 形成络合物。振动光谱表明,腙在双 CN 键上仅具有邻羟基基团,而腙在苯环的对位上具有额外的 OH 基团,形成了以水为配体的单体铜 (II) 配合物,而腙与间位取代基(Cl、OCH3)形成双核铜配合物,其中两个铜(II)离子通过酚氧原子桥接腙分子。通过热重分析研究了制备的铜 (II) 配合物的热性能。振动光谱表明,腙在双 CN 键上仅
Gallium(III) complexes of aroylhydrazones derived from nicotinic acid hydrazide in solid state and in solution
β2) with ligands H2L1−H2L4 amounted to 12.4, 11.5, 10.6 and 11.2 respectively, showing that additional methoxy group in meta position decreases stability of complexes. The complexes isolated from ethanolic solution had 1:2 (metal:ligand) stoichiometry. In all complexes the remaining charge of metal ion was neutralized by nitrate ions as shown by IR spectroscopy. Only for H2L2 the keto-enol tautomeric