Self-assembly reactions of Zn 2+ and L 5− (H 5 L = 2,5-(6-(4-carboxyphenylamino)-1,3,5-triazine-2,4-diyldiimino) diterephthalic acid) lead to the formation of two new ABWtype zeolitic metal−organic frameworks (Z-MOFs): (Me 2 NH 2 )[Zn 2 L]·3.5DMF (1) and (Me 2 NH 2 )[Zn 2 L(H 2 O)]· 2DMF·8H 2 O (2) (DMF = N,N-dimethylformamide). They are the first two Z-MOFs which are built of the same pentacarboxylate ligand and metal ion but have two configurations and channel shapes (distorted honeycomband herringbone-shaped channels for 1 and 2 respectively). They can demonstrate interesting structural transformations triggered by vacuum heating or soaking in different solvents. While direct transformations between 1 and 2 were revealed to be not feasible, 2 could be first transformed to a crystalline intermediate 3 and then into 1. Furthermore, while transformations between 2 and 3 are irreversible, those between 1 and 3 are reversible, accompanied by a 26 nm shift of their emission peak positions. In comparison to the ligand, 1, 2, and 3 exhibit blue shifts in their luminescent emission peaks and have intensive blue emission in both solid and solution phases. The efficient and selective quenching of their photoluminescence by a series of nitroaromatics (NACs) solutions phase and by nitrobenzene (NB) vapor makes them promising probes for detecting NACs. 1− 3 represent the first series of MOFs as promising photoluminescent probes for detecting dinoseb down to 2.4 ppm. The electron transfer, long-range energy transfer, and/or electrostatic interactions between the frameworks and NACs mainly contribute to the quenching mechanisms. ■ INTRODUCTIONZeolites, characterized by interconnected tetrahedra of SiO 4 / AlO 4 and non-interpenetrating porosity, are among the most important porous solid-state materials. However, their applications have generally been limited to small molecules due to small pore and channel sizes. 1,2 In contrast, metal organic frameworks (MOFs) have more tunable pores, channels, and functionalities. The functionalities can come from individual inorganic and organic components and synergic interactions between them. 3−5 Their porosities and functionalities can jointly help MOFs to find niche applications. 6−8 Among them, responsive MOFs (dynamic frameworks or "breathing" MOFs) with flexible frameworks can reversibly deform their pores or channels under various external stimuli 9−13 such as light, temperature, and guest molecules, making them intriguing candidates for selective capture, storage, release, and separation of molecules, and thus chemical sensing. 14−17 Zeolitic metal organic frameworks (Z-MOFs), a unique subset of MOFs, represent a perfect union of zeolites and MOFs. 18−22 Among the over 170 natural or synthetic zeolites, ABW (sra, SrAl 2 , or CeCu 2 ) represent a topology in which 4-, 6-, and 8-membered rings are used as building blocks. A number of ABW-type Z-MOFs based on tetrahedral molecular building blocks (MBBs) and organic linkers have been reported. 23−28 Interestingly, depending on the st...

A novel ABW-type luminescent metal–organic framework was applied for selective visualization sensing of trace amounts of 2,6-dichloro-4-nitroaniline and vapor sensing of trifluralin.

Molecular oxygen activation has always been a difficult issue and challenge in heterogeneous photocatalytic aerobic oxidations due to the kinetically persistent or spin-forbidden nature of O 2 . In this work, a highly delocalized interpenetrated 3D MOF photocatalyst with high stability, Zn-TACPA (H 3 TACPA = tris(3carboxybiphenyl)amine), based on vinyl-functionalized triphenylamine and bipyridine ligands has been fabricated and employed as a reactive oxygen species (ROS) generator to catalyze the photooxidative CDC/aromatization tandem reaction of glycine esters and styrenes. In comparison to a similar triphenylamine MOF (Zn-TCA), DFT calculations and extensive control experiments reveal that the introduction of functional vinyl double bonds not only optimizes the visible-light absorption and photoredox potential of triphenylamine ligand to powerfully activate O 2 via a singleelectron-transfer process but also improves the conjugation degree, charge-carrier separation, and migration efficiency of the MOF semiconductor for rapid O 2 activation. Such an oxygen activation ability endows Zn-TACPA with a catalytic yield of up to 91%, 2.6 times higher than that of Zn-TCA. Furthermore, the crucial intermediates and activation processes were also properly captured and monitored by a series of experiments including ESI-MS, ESR, IR, and fluorescence analyses to better understand the possible catalytic mechanisms.

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