Toxic Aromatics Inclusion and Water Vapor Adsorption/Desorption of a 3D Supramolecular Architecture via π–π Assembly of 2D Zn-Based Layered MOFs

A three-dimensional (3D) supramolecular architecture, {[Zn(dpds)(bdc)]·MeOH·1.5H2O}n (1) (dpds = 1,2-bis(4-pyridyl)disulfide and bdc2– = dianion of 1,4-benzenedicarboxylic acid), assembled by a two-dimensional (2D) layered metal–organic frameworks (MOFs) via interlayer sandwich-type πpyridyl–πbenzene–πpyridyl and πpyridyl–πpyridyl interactions, is examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy to reveal their structures and chemical environments. Compound 1 exhibits a significant water vapor adsorption/desorption isotherm for pretreated 1, which displays a maximum value of 215.5 cm3g–1 at a relative pressure P/P0 = 1.00, corresponding to adsorption of approximately four water molecules per asymmetric unit (ASU). In addition, a series of toxic aromatics, namely, benzene (PhH), toluene (PhCH3), anisole (PhOCH3), and nitrobenzene (PhNO2), can be absorbed by 1 in liquid phases to generate new host–guest compounds, {[Zn(bdc)(dpds)]·0.5Ph·1.5H2O}n (1⊃Ph), {[Zn(bdc)(dpds)]·0.5Ph(CH3)·H2O}n (1⊃PhCH3), {[Zn(bdc)(dpds)]·0.5PhOCH3·1.5H2O}n (1⊃PhOCH3), and {[Zn(bdc)(dpds)]·0.5Ph(NO2)·1.5H2O}n (1⊃PhNO2), which have been indetified by IR, X-ray diffraction method, and TG analysis. Structural characteristics and photoluminescent properties associated with theoretical calculation for 1⊃Ph, 1⊃PhCH3, 1⊃PhOCH3, and 1⊃PhNO2 are studied and discussed.