Cation recognition of luminescent ionophore-dansyl-monoaza-18-crown-6

Li, LD Wu, YG Tong, AJ Long, WQ

Ld. Li et al., Cation recognition of luminescent ionophore-dansyl-monoaza-18-crown-6, CHEM J CH U, 22(9), 2001, pp. 1472-1476

14

CHINESE

Article

Chemistry

CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE

0251-0790 → ACNP

22

9

2001

1472 - 1476

ISI

0251-0790(200109)22:9<1472:CROLI>2.0.ZU;2-Q

Using the title ionophore DNS-MAC(O-5) as the host, its cation recognition properties for Li+, Na+, K+, Mg2+, Ba2+ and Pb2+ in acetonitrile and in aqu eous solution were studied by fluorescence and NP-RTP method, respectively. The corresponding stability constants and the recognition sensitive factor s for the host-guest complexes were determined. The results proved that the charge of guest cation and the spatial matching requirement between azacro wn ring and the cation are the two most important factors on the recognitio n process. DNS-MAC(O-5) undergoes obviously a spectral change upon binding with cation. These changes are mainly controlled by the charge density of t he cation. When the azacrown ether moiety of the ionophore was coordinated with a cation, not only the dipole moment of the lumino-ionophore was incre ased, but also it was more favorable for the photoinduced intramolecular ch arge transfer, so the stability of exited state was increased and the fluor escence spectrum was red shifted. At the same time, the relative fluorescen ce quantum of DNS-MAC(O-5) in water and acetonitrile was determined by the comparative method in this paper.