A trans-N,N′-methylated hexaazamacrocycle precursor L3, derived from the hexadentate polyamine macrocycle L (Py2aneN6), was synthesized for the first time. The crystal structures of the intermediates L1·8H2O and L2I2·H2O showing two trans quaternary nitrogen atoms have also been determined by single-crystal X-ray crystallography. By the alkylation of the trans secondary amines present in L3, two novel macrocyclic molecular probes 1 and 2 linked to two nitrophenylurea and two nitrophenylthiourea groups, respectively, are reported. Crystals of 1·2CDCl3 suitable for single-crystal X-ray diffraction analysis were also obtained. The coordination ability of compounds 1 and 2 toward hydrated nitrate salts of cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) was studied. Their responses toward different anions (fluoride (F-), chloride (Cl-), bromide (Br-), iodide (I-), hydroxide (OH-), acetate (AcO-), cyanide (CN-), dihydrogen phosphate (H2PO4-), nitrate (NO3-) and perchlorate (ClO4-)) in DMSO solution were evaluated by UV-vis absorption spectroscopy. The immobilization of probe 1 in cellulose supported systems to evaluate its efficiency in the fast recognition of different anions (F-, AcO-, CN-, H2PO4-) in aqueous phase was also described.
- Anion sensor
- Solid support