BINDING OF IONIC PYRENE DERIVATIVES TO POLYELECTROLYTES - A UV ABSORPTION AND FLUORESCENCE STUDY

The binding of pyrenesulfonic acid and pyrenebutyric acid to poly(viny l benzyl trimethylammonium) chloride was investigated by UV and fluore scence spectroscopy. It was found that the binding constant was 7.5 x 10(4) and 3.5 x 10(4) M-1, respectively. The addition of the polyelect rolyte quenches the fluorescence of the pyrene group, and at the same time the typical excimer emission appears. This emission originates in pre-formed ground state aggregates of the pyrene derivatives incorpor ated into the polyion domain. Similar effects were observed when anion ic polyelectrolytes, poly(styrene sulfonic), and poly(vinyl sulfonic) acids were added to cationic pyrene derivatives. The binding constants depend on the length of the aliphatic sidechain of the derivatives.