Abstract

The reaction of copper salts with Schiff base ligand: [4-[(1E)-N-{2-[(Z)-(4-methoxybenzylidene)amino]ethyl}ethanimidoyl]benzene-1,3-diol] derived from the condensation of ethylenediamine, 2-hydroxy-1-(4-hydroxyphenyl)ethenone and 4-methoxybenzaldehyde afforded copper complexes bearing chloride, bromide, thiocyanate, nitrate, and acetate. The complexes exhibited crystalline features and excellent thermal stability up to 450 °C. The powder X-ray diffraction pattern suggests a well-defined crystalline structure with average crystallite sizes of < 52 nm. The scavenging ability of 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid radicals by the synthesized compounds was studied for their antioxidant potential and screening for antimicrobial activity by p-iodonitrotetrazolium chloride colorimetric assay. The investigated assays suggest that the synthesized compounds are potent antiradical and antimicrobial agents.

• Research highlights

• An eco-friendly method was followed for the synthesis of functionalized tridentate ONN Schiff base ligand.

• Five Schiff base copper(II) complexes were synthesized bearing chloride, bromide, thiocyanate, nitrate, and acetate.

• Structural features were characterized by CHN, PXRD, TG-DTG, NMR, UV–Vis, and FT-IR spectro-analytical techniques.

• Schiff base ligand and its copper complexes showed good to excellent DPPH and ABTS radicals scavenging capability.

• Cu(II) complexes of Schiff base ligand (MEB) showed good antimicrobial properties via the p-iodonitrotetrazolium chloride (INT) colorimetric assay.

摘要

铜盐与席夫碱配体的反应：[4-[（（1 E）-N- {2-[（Z由乙二胺，2-羟基-1-（4-羟基苯基）乙酮和4-甲氧基苯甲醛缩合得到的）-（4-甲氧基亚苄基）氨基]乙基}亚氨基酰亚胺基]苯-1,3-二醇]制得带有氯化物的铜配合物，溴化物，硫氰酸盐，硝酸盐和乙酸盐。该配合物表现出结晶特征，并在高达450°C的温度下具有出色的热稳定性。粉末X射线衍射图表明具有明确定义的晶体结构，平均晶粒尺寸小于52nm。研究了合成化合物清除2,2-二苯基-1-吡啶并肼基和2,2'-叠氮基双（3-乙基苯并噻唑啉-6-磺酸基）的抗氧化能力，并通过p筛选其抗菌活性。-碘硝基四唑氯化物比色法。研究的测定表明合成的化合物是有效的抗自由基和抗微生物剂。

• 研究重点

• 遵循生态友好的方法合成功能化的三齿ONN Schiff碱配体。

• 合成了五种带有氯化物，溴化物，硫氰酸盐，硝酸盐和乙酸盐的席夫碱铜（II）配合物。

• 通过CHN，PXRD，TG-DTG，NMR，UV-Vis和FT-IR光谱分析技术对结构特征进行了表征。

• 席夫碱配体及其铜络合物表现出良好的DPPH和ABTS自由基清除能力。

• Schiff碱配体（MEB）的Cu（II）配合物通过对碘碘代四唑氯化物（INT）比色法显示出良好的抗菌性能。