An Anionic Interpenetrated Zeolite-Like Metal-Organic Framework Composite As a Tunable Dual-Emission Luminescent Switch for Detecting Volatile Organic Molecules.

The luminescent MOF [(CH3 )2 NH2 ]2 [(Zn2 O)L]⋅5 DMF (NENU-519, NENU=Northeast Normal University) with a zeolite BCT topology was successfully synthesized. It is a rare example of a two-fold interpenetrated framework with a zeolite topology. NENU-519 demonstrates the ability to selectively adsorb cationic dyes. Furthermore we developed Rh6@NENU-519 (Rh6=Rhodamine 6G) as a dual-emitting sensor for probing different volatile organic molecules (VOMs) due to an energy transfer between L and the dye. The composite can be used to distinguish the isomers of o-, m-, and p-xylene and ethylbenzene using the emission-peak-height ratios of L to the dye as detectable signals, in which the readout signals are involved in the interactions between the dye@MOF composite and the guest analytes. Moreover, Rh6@NENU-519 can serve as a luminescent switch for the detection of different aromatic compounds, like benzene, benzene substituted with different groups, and pyridine. In other words, the Rh6@NENU-519 composite can be used as molecular decoder of the structural information of different VOMs into recognizable luminescent signals. Hopefully this work will open a new corridor to develop luminescent guest@MOF composites as sensors for practical applications.