Radical Anion Formation Exhibiting “Turn-on” Fluorescence Sensing of Hydrazine Using a Naphthalene Diimide (NDI) Derivative of Donor-Acceptor-Donor (D-A-D) Molecular Structure
In this paper, a synthesis of naphthalene diimide (NDI) derivative of donor-acceptor-donor (D-A-D) molecular structure substituted with a long alkyl chain (12 carbons) containing naphthalene hydrazide at the imide position is reported. The reduced emission quantum yield (f= 0.01-0.03) of the NDI derivative in various solvents indicates the perturbation of the electronic state of -electron deficient NDI (A) by the peripheral naphthalene (D) units. The investigation of the influence of alkyl chain and naphthalene substituent on the self-assembling properties of the NDI derivative reveals an isodesmic mode of self-assembly in chloroform/methylcyclohexane (CHCl3/MCH, 1:9, v/v) mixture. The self-assembling nature of the NDI derivative also results in the formation of the organogel in CHCl3/MCH (1:9, v/v) mixture, and gel formation is well-comprehended by the techniques such as P-XRD, rheological studies, and FT-IR measurements. Further, radical anion (NDI.-) formation of acidic NDI was used as a sensing tool for hydrazine by a fluorescent “turn-on” (f =0.12) method in solution (DMSO), film, and gel state with a detection limit of 284.1 ppb in DMSO and 32 ppb in the gel state.