A Rare L1D+R1D -> 3D Luminescent Dense Polymer as Multifunctional Sensor to Nitro Aromatic Compounds, Cu2+, and Bases

A rarely reported L1D (left-handed helical 1D chain) + R1D (right-handed helical 1D chain) → 3D polycatenated network, [Cd(H2ttac)bpp]n (1), constructed from the vertical interpenetration of triple-stranded homochiral helices, has been synthesized under hydrothermal condition by H4ttac (1,1′,2′,1″-terphenyl-4,4′,4″,5′-tetracarboxylic acid), 1,3-bis(4-pyridyl)propane (bpp), and Cd(NO3)2·4H2O. The luminescent properties of 1 and the ones immersed in various kinds of organic compounds and nitrate@DMF solutions have been investigated. Importantly, 1 shows highly sensitive response to nitro aromatic compounds and Cu2+ through luminescence quenching effects, making it a promising luminescent sensor for nitro aromatic compounds and Cu2+. Besides, experiments upon deprotonation by NaOH, KOH, methylamine, and triethylamine are conducted, respectively. As base increases, the luminescence spectra exhibit gradual blue shifts. The mechanisms of the sensing properties have been studied in detail.