S. Patra, Vinod P. Boricha, K. R. Sreenidhi
May 5, 2010
Citations
0
Influential Citations
18
Citations
Journal
Inorganica Chimica Acta
Abstract
Abstract Metalloreceptors containing ruthenium(II) bipyridine unit as fluorophore and pendant macrocyclic units as ionophore have been synthesized and their luminescence and electrochemical properties have been investigated. Ion-binding study of these fluoroionophore with the anions F − , Cl − , Br − , I − , H 2 PO 4 - , ClO 4 - , NO 3 - , BF 4 - , CH 3 COO − , and HSO 4 - and cations Na + , K + , Mg 2+ , Ca 2+ , Zn 2+ , Ba 2+ , Sr 2+ Cd 2+ , Hg 2+ , Pb 2+ and Cu 2+ , monitored by luminescence and 1 H NMR spectral changes, reveal strong interactions of H 2 PO 4 - and F − for 2 and 3 and of Cu 2+ only for 3 . Luminescence titrations for 2 and 3 have been carried out to determine binding constants ( K s ), and the calculated values are in the range 2.85 × 10 2 to 4.48 × 10 4 M −1 . The 1 H NMR spectral changes for 2 and 3 with the addition of increasing concentration of F − and H 2 PO 4 - exhibit substantial low-field shift of the CO NH proton indicating its involvement in complex formation with the anions. The H 2 PO 4 - adduct of 2 and 3 have been isolated and characterized by 1 H and 31 P NMR, mass and IR spectroscopy. The results are discussed in light of selectivity, structures of the anion bound complexes and their luminescence property.