1,5-NDS2−-directed synthesis of transition metal based cucurbit[5]uril supramolecular material for efficient NFX antibiotic detection

Three new coordination polymers based on cucurbit[5]uril (Q[5]) have been successfully synthesized. Their chemical formulas are {[Ni(H 2 O) 2 (Q[5])]·(1,5-NDS)}·14H 2 O ( 1 ), {[Co(H 2 O) 2 (Q[5])]·(1,5-NDS)}·15H 2 O ( 2 ), and {[Zn(H 2 O) 2 (Q[5])]·(1,5-NDS)}·10H 2 O ( 3 ). These polymers were obtained through the self-assembly of Q[5] with the corresponding transition metal salts in the presence of 1,5-naphthalenedisulfonic acid (1,5-H 2 NDS). Single- crystal X- ray diffraction analysis of these three coordination polymers has unveiled that the deprotonated 1,5-NDS²⁻ anions play a pivotal role in their self - assembly. Within these complexes, 1,5-NDS²⁻ anions facilitate the direct coordination of Ni 2+ /Co 2+ /Zn 2+ with the carbonyl oxygen atoms at the ports of Q[5], leading to the formation of one - dimensional (1D) supramolecular chains. Moreover, the non - covalent interactions among the 1D chains, along with those arising from the interplay between 1,5 - NDS²⁻ anions and the outer surface of Q[5] within the chains, generate a cooperative effect. This cooperative effect, where the combined action of these interactions is more powerful than the simple sum of their individual contributions, drives the further assembly of the 1D chains into a three-dimensional (3D) supramolecular framework featuring specific channel structures. Performance tests reveal that the Q[5]-Ni 2+ -based supramolecular assembly has high selective recognition for the antibiotic norfloxacin (NFX).