School of Chemical Sciences, Goa University, Taleigao Plateau, 403 206, Goa, India.
Department of Chemistry, BSS Art's, Science and Commerce College, Makni, Tq. Lohara, 413604, Maharashtra, Dist. Osmanabad, India.
ChemistryOpen. 2022 Jun;11(6):e202200060. doi: 10.1002/open.202200060.
A new 'Off-On' system designed and synthesised by functionalisation of a naphthalene diimide (NDI) core with dimethylamine produces 4,9-bis(dimethylamino)-2,7-dioctylbenzo[lmn][3,8]-phenanthroline-1,3,6,8-(2H,7H)-tetraone, abbreviated as DDPT (1). DDPT 1 was synthesised using a simple strategy, namely aromatic nucleophilic substitution using Br -NDI with dimethylamine at 110 °C. DDPT was characterized by H and C NMR spectroscopy, ESI mass spectrometry and elemental analysis. DDPT 1 was then used for optical studies through protonation of its dimethylamine core with trifluoroacetic acid (TFA), blue-shifting the absorption band from 600 nm to 545 nm in solution. Interestingly, the fluorescence of DDPT 1 is weak in solution with a quantum yield Φ=0.09, which is significantly enhanced to Φ=0.78 upon addition of TFA. The limit of detection (LOD) was determined to 2.77 nm. Furthermore, DDPT 1 can be used for naked eyed detection not only under UV light (365 nm) but also using visible light, as clear changes can be clearly seen upon addition of TFA. The binding constant of DDPT was calculated to 2.1×10 m . Importantly, DDPT 1 showed reversible switching by alternative addition of acid (TFA) and base (triethylamine) without loss of activity. Immobilised on paper, DDPT 1 can be used for strip-test sensing in which the colour changes from blue to reddish when expose to TFA vapours and reverse in the presence of triethylamine vapours.
一种新的“开-关”系统，通过在萘二酰亚胺（NDI）核心上功能化二甲胺来设计和合成，产生 4,9-双（二甲氨基）-2,7-二辛基苯并[lmn][3,8]-菲咯啉-1,3,6,8-(2H,7H)-四酮，缩写为 DDPT（1）。DDPT 1 是通过简单的策略合成的，即在 110°C 下用 Br-NDI 和二甲胺进行芳基亲核取代。DDPT 通过 1 H 和 13 C NMR 光谱、ESI 质谱和元素分析进行表征。然后，通过三氟乙酸（TFA）对其二甲胺核进行质子化，DDPT 1 用于光学研究，使吸收带从溶液中的 600nm 蓝移至 545nm。有趣的是，DDPT 1 在溶液中的荧光很弱，量子产率 Φ=0.09，加入 TFA 后显著增强至 Φ=0.78。检测限（LOD）确定为 2.77nm。此外，DDPT 1 不仅可以在紫外光（365nm）下，而且可以在可见光下用于肉眼检测，因为加入 TFA 后可以清楚地看到明显的变化。DDPT 的结合常数计算为 2.1×10 m 。重要的是，DDPT 1 通过交替添加酸（TFA）和碱（三乙胺）进行可逆切换，而不会失去活性。固定在纸上，DDPT 1 可用于条带测试传感，当暴露于 TFA 蒸气时，颜色从蓝色变为红棕色，而在存在三乙胺蒸气时则会反转。
