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

A family of thiophene-based metal–organic
frameworks (MOFs),
[Zn­(L)­(BBI)·(H2O)2] (1) (BBI
= 1,1′-(1,4-butanediyl)­bis­(imidazole)) and [Cd­(L)­(TPOM)0.75]·xS (2) (TPOM = tetrakis­(4-pyridyloxy-methylene)
methane, S represents noncoordinated solvent molecules) was constructed
by employing a new linear thiophene-functionalized dicarboxylic acid
(benzo-(1,2;4,5)-bis­(thiophene-2′-carboxylic acid, H2L) to assemble with d10 ions in the presence of a flexible
ancillary ligand under solvothermal conditions, which exhibit diverse
structures. Most strikingly, both compounds 1 and 2 could be efficient luminescent sensory materials that are
highly selective and sensitive to environmental contaminants, especially
for Hg­(II), Cu­(II), Cr­(VI), and salicylaldehyde, and yet remain unaffected
by other molecules that may coexit. Furthermore, this is the first
report on MOF-based sensors capable of recyclable detection of Hg­(II),
Cr­(VI), and salicylaldehyde so far. The luminescent sensing mechanism
was studied in detail as well. In addition, compound 2 is one of the rare examples of high-performance MOFs trapping 2,4-dichlorophenol
from the wasted methanol solution.