Photobehaviour and DNA interaction of styrylquinolinium salts bearing thiophene substituents†
Abstract
A photochemical and photophysical study on three quinolinium iodides, free and complexed with DNA, was carried out by stationary and pulsed techniques. The comparison with the behaviour of pyridinium analogues pointed to a reduction in the photoisomerization yield of these compounds in favour of fluorescence and internal conversion. These quinolinium salts showed a good affinity towards salmon DNA with association constants ≈104 M−1 and a different photobehaviour when involved in the formation of