Luminescence sensing for nitroaromatics of a two-fold interpenetrating znic based metal-organic framework

Abstract

A zinc based metal-organic framework (MOF), namely, {Zn(L)·2H2O}n (1) {H2L = 4-(3,5-dicarboxyphenyl)-4,2′:6′,4′'-terpyridine}, has been successfully assembled in a hydrothermal environment. The single-crystal X-ray diffraction demonstrate that the structure of complex 1 features a two-fold interpenetrating diamond-like 3D network with four-connected dia topology. Luminescent sensing research shows that 1 can selectively detect nitro-aromatic compounds (NACs), especially for 4-nitroaniline (4-NA) that with high quenching constant (KSV = 1.66 × 104 M−1) and low limit of detection (LOD: 36.97 μM). The sensing mechanism of NACs by 1 may come from the resonance energy transfer (RET) between substrate and sensor; however, for 4-NA, 2-NP, and 4-NP, photo-induced electron transfer (PET) also exists. Importantly, after five cycles detection test the sensing capability of 1 does not exhibit significant decrease confirms that 1 possesses high stability and good recyclability.