PG & Research Department of Chemistry, Rajeshwari Vedachalam Government Arts College, Chengalpattu, 603001, Tamilnadu, India.
Environ Sci Pollut Res Int. 2024 Oct;31(49):59490-59506. doi: 10.1007/s11356-024-35126-4. Epub 2024 Oct 2.
In this study, we report the green preparation of magnetically separable Ag/FeO/rGO nanocomposites using mangrove tree aerial root extract as a stabilising agent. The morphology, size, chemical composition, magnetic property and other characteristic parameters of synthesised Ag/FeO/rGO nanocomposite were determined by analytical techniques like Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The results proved that mangrove tree aerial root extract has the ability to reduce Ag ions, graphene oxide (GO) to Ag nanoparticle and reduced graphene oxide (rGO), respectively. The prepared Ag/FeO/rGO nanocomposite was used successfully as a prompt catalyst for synthesis of 7-phenyl-6H,7H-benzo[4,5]imidazo[2,1-b]chromeno[4,3-d][1,3]thiazin-6-one derivatives by one-pot multi-component reaction of 4-hydroxycoumarin (10 mmol), 2-mercaptobenzimidazole (10 mmol) and different arylaldehyde (10 mmol) in the presence of ethanol (10 ml) as an eco-benign solvent at reflux condition. By utilising this protocol, we have constructed 7-phenyl-6H,7H-benzo[4,5]imidazo[2,1-b]chromeno[4,3-d][1,3]thiazin-6-one derivatives in good to excellent yield of 80-90%. This synthesis involves the formation of C-C, C-N and C-S bonds. The synthesised organic heterocyclic compounds were examined for the green matrix properties such as atom economy (AE), E-factor and product mass intensity (PMI). This green protocol is of big interest due to employing simple, non-toxic heterogeneous, separable, reusable Ag/FeO/rGO as an eco-safe heterogeneous catalyst and environmentally benign ethanol as a green solvent without the use of any harmful mineral acid and toxic transition metal catalyst.
在这项研究中，我们报告了使用红树林气生根提取物作为稳定剂，通过绿色方法制备磁性分离的 Ag/FeO/rGO 纳米复合材料。通过傅里叶变换红外光谱 (FT-IR)、X 射线衍射 (XRD)、能谱 (EDX)、扫描电子显微镜 (SEM)、透射电子显微镜 (TEM) 和振动样品磁强计 (VSM) 等分析技术，确定了合成的 Ag/FeO/rGO 纳米复合材料的形貌、尺寸、化学成分、磁性等特征参数。结果证明，红树林气生根提取物具有将 Ag 离子、氧化石墨烯 (GO) 分别还原为 Ag 纳米颗粒和还原氧化石墨烯 (rGO) 的能力。所制备的 Ag/FeO/rGO 纳米复合材料成功用作 7-苯基-6H,7H-苯并[4,5]咪唑并[2,1-b]色烯[4,3-d][1,3]噻嗪-6-酮衍生物的即时催化剂，通过 4-羟基香豆素 (10 mmol)、2-巯基苯并咪唑 (10 mmol) 和不同芳醛 (10 mmol) 的一锅多组分反应，在乙醇 (10 ml) 作为环保良性溶剂存在下，在回流条件下进行。利用该方案，我们以 80-90%的良好至优秀收率构建了 7-苯基-6H,7H-苯并[4,5]咪唑并[2,1-b]色烯[4,3-d][1,3]噻嗪-6-酮衍生物。该合成涉及 C-C、C-N 和 C-S 键的形成。所合成的有机杂环化合物被检查了绿色基质性质，如原子经济性 (AE)、E 因子和产物质量强度 (PMI)。由于采用了简单、无毒的非均相、可分离、可重复使用的 Ag/FeO/rGO 作为环保非均相催化剂，以及环境友好的乙醇作为绿色溶剂，而无需使用任何有害的矿物酸和有毒过渡金属催化剂，因此该绿色方案具有很大的吸引力。
