Chemoselective Detection of 2,4,6‐trinitrophenol by Ground State Adduct Formation via Protonation of Quinoline Moiety of Non‐heme Ligands with Structural Evidence

Abstract

Four quinoline based non‐heme tetradendate ligands viz. N,N′‐di(quinolin‐8‐yl)ethane‐1,2‐diamine (BQENH2) 1, N,N′‐di(quinolin‐8‐yl)propane‐1,3‐diamine 2 (BQPNH2), N,N′‐di(quinolin‐8‐yl)butane‐1,4‐diamine (BQEBNH2) 3 and N,N′‐di(quinolin‐8‐yl)hexane‐1,6‐diamine (BQEHNH2) 4 are structurally characterized and used in selective detection of 2,4,6‐trinitrophenol (TNP) with high quenching constants. The plausible reaction mechanism involves ground state protonation of quinoline nitrogen atoms in compounds 1–4 by TNP with formation of picrate adducts (1 a‐4 a). The protonation of 1–4 is confirmed by infrared, 1H‐NMR spectroscopies, powder XRD and the single crystal structure analysis of 1 a and 4 a. Crystal structures further infer that after protonation, 1 a and 4 a are stabilized by intramolecular hydrogen bonding.

Construction of Pyrazine-Appended 1D and 3D Cobalt(II) Succinate Coordination Polymers: Influence of Solvent on Architectures and Applications in Gas Adsorption and NAC Detection

“…The sensing ability of 1 toward the different NACs is plotted in terms of their quenching efficiencies (%), as depicted in Figure S29. Thus, it unambiguously suggests that 1 can be selectively used as a chemical sensing reagent in the detection of p -NP from an aqueous mixture of other NACs. − …”