Effect of arrangement of the styryl fragment on the optical properties and complexation of mono-and bis(styryl)-substituted N-methylpyridinium perchlorates containing benzo-15-crown-5 ether moieties
Language
en
Article de revue
This item was published in
Russian Chemical Bulletin. 2007-11, vol. 56, n° 11, p. 2166-2174
Springer Verlag
English Abstract
Using 1H NMR spectroscopy and steady-state and time-resolved electronic spectroscopy, the optical properties of mono-and bis(styryl) pyridinium perchlorates and their complexes with Mg2+, Ba 2+ cations were studied. The ...Read more >
Using 1H NMR spectroscopy and steady-state and time-resolved electronic spectroscopy, the optical properties of mono-and bis(styryl) pyridinium perchlorates and their complexes with Mg2+, Ba 2+ cations were studied. The stability constants of the complexes were determined using spectrophotometric titration. The formation of inclusion complexes for Mg2+ and sandwich type complexes for Ba2+ results in fluorescence enhancement and increases the lifetimes of the excited states of the initial bis-styryl ligands. The variation of position of the styryl fragment in the pyridinium aromatic ring gives rise to photochromic crown ethers with different optical and photophysical characteristics and is also an easy route to bis(crown-ethers) of symmetrical and unsymmetrical structure.Read less <
English Keywords
bis(crown ether)
styryl dyes
benzo-15-crown-5 ether
Complex formation
E-Z photoisomerization
Origin
Hal imported