Two anthracene chromophore based metal–organic frameworks for gas adsorption and promising nitro aromatic sensing

Abstract

Two new metal–organic frameworks (MOFs), [Zn₂(μ₃-OH)(dia)(btb)·2H₂O]·EtOH·0.5DMF (1) and [Cd₂Na(btb)₂(dia)₂]·2DMF·H₂O (2) (dia = 9,10-bis(1H-imidazol-1-yl)anthracene, btb = 1,3,5-tris(4-carboxyphenyl)benzene), have been synthesized under solvothermal conditions. Compound 1 exhibits a (3,10)-connected net based on {Zn₄} SBUs and compound 2 presents a (3,8)-connected network with a [Cd₂Na] unit. The results show that both 1 and 2 have a microporous structure and selective adsorption capacity for CO₂, and the Q_st value is 36 kJ mol⁻¹ and 35 kJ mol⁻¹, respectively. Studies on luminescence sensing show that 1 and 2 are highly selective and recyclable in the detection of nitroaromatic explosives, especially for TNP. It is noteworthy that the quenching constant K_sv of 1 and 2 for TNP (2.84 × 10⁵ M⁻¹ and 2.50 × 10⁵ M⁻¹) is higher than that of most reported compounds.