Malik Suvamoy, Mondal Udayan, Jana Narayan Ch, Banerjee Priyabrata, Saha Amrita
Department of Chemistry, Jadavpur University, Kolkata - 700032, India.
Electric Mobility and Tribology Research Group, CSIR-Central Mechanical Engineering Research Institute, Durgapur, West Bengal 713209, India.
Dalton Trans. 2024 Aug 6;53(31):12995-13011. doi: 10.1039/d4dt01239a.
Eugenol, the major constituent of clove oil, has been explored as an essential natural ingredient for ages owing to its versatile pharmacological properties. However, to date, the coordination chemistry of eugenol derivatives has not been much explored. In the present work, an eugenol-based Schiff base ligand (HL) was synthesized and structurally confirmed through ESI-MS, NMR, and FT-IR spectroscopy studies. Consequently, the N,O-donor chelating ligand HL was coordinated with Cd, in the presence of bridging pseudohalides (thiocyanate, SCN, and dicyanamide, N(CN)) to synthesize two luminescent coordination polymers (CPs 1 and 2): [Cd(L)(X)] (where HL = 4-allyl-2-(((2-(benzylamino)ethyl) imino)methyl)-6-methoxyphenol and Xs are bridging pseudohalides, , SCN and N(CN)) on a Cd-eugenol scaffold. The CPs depicted structural diversity, bulk-phase purity, thermal stability, and the presence of interlayer supramolecular C-H⋯π interactions together with C-H⋯S (for CP 1) and C-H⋯N (for CP 2) interactions. The CPs further exemplified themselves as selective and sensitive 'turn-off' probes towards trinitrophenol (TNP) (quenching efficiency: 82.02% and 83.86% for 1 and 2) among a pool of hazardous nitroaromatic compounds (NACs). Accordingly, 1 and 2 exhibited an ultralow limit of detection (LOD) of 0.29 and 0.15 μM, with high quenching constants () of 5.91 × 10 and 17.60 × 10 M, respectively. In addition, TNP sensing events were evidenced to be recyclable and exhibited fast response (∼31 s, 1, and ∼40 s, 2), which increased its real-world viability. Vapor phase TNP sensing was also accomplished upon drop-casted CP films. Experimental investigations and theoretical DFT study confirmed the cooperative occurrence of RET-IFE-PET-collisional quenching and non-covalent π⋯π stacking as key factors involved in the TNP sensing performance. The competency of 1 and 2 in the detection of TNP from several complex environmental matrices (CEMs), matchstick powder, river and sewage water, and soil specimens, was also established with good recovery (∼66-86% and ∼68-93% for 1 and 2, respectively) and high values (3.90-11.39 × 10 and 6.17-18.79 × 10 M for 1 and 2, respectively).
丁香酚是丁香油的主要成分，由于其具有多种药理特性，长期以来一直被视为一种重要的天然成分。然而，迄今为止，丁香酚衍生物的配位化学研究还很少。在本工作中，合成了一种基于丁香酚的席夫碱配体（HL），并通过电喷雾电离质谱（ESI-MS）、核磁共振（NMR）和傅里叶变换红外光谱（FT-IR）研究对其结构进行了确认。因此，在桥连拟卤化物（硫氰酸盐，SCN，和双氰胺，N(CN)）存在的情况下，N,O供体螯合配体HL与镉配位，合成了两种发光配位聚合物（CPs 1和2）：[Cd(L)(X)]（其中HL = 4-烯丙基-2-(((2-(苄基氨基)乙基)亚氨基)甲基)-6-甲氧基苯酚，X为桥连拟卤化物，SCN和N(CN)），其基于镉-丁香酚支架。这些配位聚合物表现出结构多样性、体相纯度、热稳定性，以及层间超分子C-H⋯π相互作用以及C-H⋯S（对于CP 1）和C-H⋯N（对于CP 2）相互作用。这些配位聚合物进一步证明自己是对三硝基苯酚（TNP）具有选择性和敏感性的“猝灭型”探针（猝灭效率：1和2分别为82.02%和83.86%），在一系列有害硝基芳烃化合物（NACs）中。因此，1和2表现出超低检测限（LOD），分别为0.29和0.15 μM，猝灭常数（）分别高达5.91×10和17.60×10 M。此外，TNP传感事件被证明是可回收的，并且响应迅速（1约为31 s，2约为40 s），这增加了其在实际应用中的可行性。通过滴铸CP薄膜也实现了气相TNP传感。实验研究和理论密度泛函理论（DFT）研究证实，共振能量转移-内滤效应-光致电子转移-碰撞猝灭以及非共价π⋯π堆积共同作用是TNP传感性能的关键因素。还确定了1和2在从几种复杂环境基质（CEMs）、火柴粉、河水和污水以及土壤样品中检测TNP的能力，回收率良好（1和2分别约为66 - 86%和68 - 9%），值较高（1和2分别为3.90 - 11.39×10和6.17 - 18.79×10 M）。
