Synthesis, structure, and luminescent properties of oligothiophene-containing metal–organic frameworks

Abstract

Metal-organic frameworks (MOFs) based on Zn and functionalized bithiophene dicarboxylic acids are reported, [Zn 2 (L1) 2 (DMA) 2 ?3 DMF] n (1), [Zn(L2)(DMA) 2 ] n (2), [Zn(L3)(bpe) 0.5 ] n (3), [Zn(L1)(bpe)?2 DMF] n (4), and [Zn 3 (L2) 3 (bpe) 2 ?4 DMF ? H 2 O] n (5) (H 2 L1 = 3,39-diphenyl-2,29-bithiophene-5,59-dicarboxylic acid, H 2 L2 = 3,39-dihexyl-2,29-bithiophene-5,59-dicarboxylic acid, H 2 L3 = 2,29-bithiophene-5,59-dicarboxylic acid, DMA = dimethylamine, DMF = N,N-dimethylformamide, bpe = trans-1,2-bis(4-pyridyl)ethylene). MOFs 1, 2, and 4 consist of 2-D 4-connected sheets while 3 and 5 are 3-D interpenetrated networks with pcu and (4,6)-connected seh topology, respectively. The emission spectra and lifetimes of 1-5 have been determined: 4 and 5 exhibit reduced emission relative to 1 and 2, respectively, attributed to energy transfer quenching by the bpe, whereas 3 does not exhibit a reduction in emission intensity. Solid state lifetime measurements of 1-5 show that the emission decays are similar to those of the constituent ligands.

Zirconium Metal–Organic Frameworks Containing a Biselenophene Linker: Synthesis, Characterization, and Luminescent Properties

“…All ligands show a trans disposition of their heteroatoms on the two heterocyclic rings, as found in their uncoordinated form (see also Figure S1). ,, Linker deviation from planarity (with dihedral angles between the two heterocyclic rings falling in the 6–25° range) is observed in all cases, as was already found for other structurally characterized coordination compounds from the literature containing the TpTp 2– ligand …”

Metal–Organic Frameworks Constructed from a New Thiophene-Functionalized Dicarboxylate: Luminescence Sensing and Pesticide Removal

“…It is well-known that conjugated thiophene ligands are important organic moieties in the syntheses of a variety of optoelectronic materials owing to their nature of good electron-transfer ability and structural rigidity. , So far, MOFs constructed from thiophene-based ligands are rather limited, − and the overwhelming majority for the system was based on thiophene-2,5-dicarboxylic acid. − Interestingly, Lan and Su recently successfully assembled 3,4-dimethylthieno­[2,3- b ]­thiophene-2,5-dicarboxylic acid with Zn­(II) to form S-containing MOFs for selective separation of transition-metal ions. Wang and Su reported a series of Zn­(II) coordination polymers prepared from a thiophene-derivatized carboxylate dithieno­[3,2- b :2′,3′- e ]­benzene-2,6-dicarboxylic acid as the major ligand with different N-donor ligands as ancillary colinkers, which demonstrate interesting photoluminescence.…”

Synthesis, Structure, and Magnetic Properties of Bithiophene- and Terthiophene-Linked Manganese Metal–Organic Frameworks

“…Previously synthesized MOFs containing this linker are also 2D frameworks; changing the metal center thus far has not caused changes in dimensionality of 3PhT 2 DC 2– MOFs. Literature precedent , for the solid state structure of 3,3′-diphenyl-2,2′-bithiophene and its derivatives suggests that the conformations that are accessible in the solid state will lead to 3PhT 2 DC 2– having a linking angle of 140–150°. Ligands with such linking angles alone are not conducive to forming 3D frameworks .…”

“…Methodical crystal engineering can be applied via incorporation of oligothiophene linkers into metal–organic frameworks to obtain orientational control of coordination polymers . A myriad of MOFs containing thiophene-2,5-dicarboxylic acid have been reported, though few oligothiophene metal–organic frameworks, − polyhedra, or covalent-organic frameworks have been synthesized. Examples of conjugated triaryl MOFs are limited to those containing p -terphenyl linkers .…”