Synthesis of novel triarylamine-based dendrimers with N4,N6-dibutyl-1,3,5-triazine-4,6-diamine probe for electron/energy transfers in H-bonded donor–acceptor–donor triads and as efficient Cu2+ sensors
作者:Muthaiah Shellaiah、Yesudoss Christu Rajan、Hong-Cheu Lin
DOI:10.1039/c2jm00112h
日期:——
Two novel highly soluble triarylamine dendrimers TPAD1 and TPAD2 with N4,N6-dibutyl-1,3,5-triazine-4,6-diamine probe were synthesized via normal synthetic routes. Both dendrimers (TPAD1 and TPAD2) form H-bonded donorâacceptorâdonor (DâAâD) supramolecular triads TPAD1-PBI-TPAD1 and TPAD2-PBI-TPAD2 with 3,4,9,10-perylene tetra carboxylic diimide derivative (PBI). The presence of multiple H-bonds in the solution state was elucidated by 1H NMR titrations and IR spectral studies. J-aggregations and electron/energy transfers provided by both dendrimers were verified by UVâVis and photoluminescence (PL) titrations with PBI and the particle sizes of supramolecular triads were calculated by X-ray diffraction (XRD) analysis. Similarly, both dendrimers also showed sensitivities towards Cu2+ in comparison with 19 interfering metal ions, which were evidenced via UVâVis and PL titraions in both single and dual metal systems. The maximum detection limit of Cu2+ ions was determined to be 20 ppm from PL titrations for both dendrimers, and the 1â:â2 stoichiometry of the complexes formed by both dendrimers (TPAD1-Cu2+ and TPAD2-Cu2+) were calculated by Job plots based on UVâVis absorption titrations. More importantly, the binding mechanism of the 1,3,5-triazine-4,6-diamine probe of both dendrimers was well characterized by 1H and 13C NMR titrations ([D8]THFâ:âD2O = 2â:â1 in vol.) and supported by the fluorescence reversibility by adding metal ions and PMDTA sequentially.
通过常规合成路线合成了两种新型高溶解性三芳基胺树枝状聚合物 TPAD1 和 TPAD2,其探针为 N4,N6-二丁基-1,3,5-三嗪-4,6-二胺。这两种树枝状聚合物(TPAD1 和 TPAD2)与 3,4,9,10-苝四羧酸二亚胺衍生物(PBI)形成了以 H 键结合的供体-受体-单体(DâAâD)超分子三元组 TPAD1-PBI-TPAD1 和 TPAD2-PBI-TPAD2。通过 1H NMR 滴定和红外光谱研究,阐明了溶液状态中存在多个 H 键。通过紫外可见光和光致发光(PL)滴定法验证了这两种树枝状聚合物提供的 J 聚合和电子/能量转移,并通过 X 射线衍射(XRD)分析计算了超分子三元组的粒度。同样,与 19 种干扰金属离子相比,这两种树枝状聚合物对 Cu2+ 也表现出敏感性。根据紫外可见吸收滴定法绘制的约伯图计算出了两种树枝状聚合物(TPAD1-Cu2+ 和 TPAD2-Cu2+)形成的复合物的 1:â2配位比。更重要的是,通过 1H 和 13C NMR 滴定法([D8]THFâ:âD2O = 2â:â1 in vol.),这两种树枝状聚合物的 1,3,5-三嗪-4,6-二胺探针的结合机制得到了很好的表征,并且通过依次添加金属离子和 PMDTA 的荧光可逆性得到了支持。