Highly Efficient Removal of Neonicotinoid Insecticides by Thioether-Based (Multivariate) Metal–Organic Frameworks

Circumventing
the impact of agrochemicals on aquatic environments
has become a necessity for health and ecological reasons. Herein,
we report the use of a family of five eco-friendly water-stable isoreticular
metal–organic frameworks (MOFs), prepared from amino acids,
as adsorbents for the removal of neonicotinoid insecticides (thiamethoxam,
clothianidin, imidacloprid, acetamiprid, and thiacloprid) from water.
Among them, the three MOFs containing thioether-based residues show
remarkable removal efficiency. In particular, the novel multivariate
MOF {SrIICuII6[(S,S)-methox]1.5[(S,S)-Mecysmox]1.50(OH)2(H2O)}·36H2O (5), featuring narrow functional channels decorated with both −CH2SCH3 and −CH2CH2SCH3 thioalkyl chainsfrom l-methionine and l-methylcysteine amino acid-derived ligands, respectivelystands
out and exhibits the higher removal efficiency, being capable to capture
100% of acetamiprid and thiacloprid in a single capture step under
dynamic solid-phase extraction conditionsless than 30 s. Such
unusual combination of outstanding efficiency, high stability in environmental
conditions, and low-cost straightforward synthesis in 5 places this material among the most attractive adsorbents reported
for the removal of this type of contaminants.