The fluorescence properties of selected derivatives of 6-methoxyanthracene-
2-carboxylic acid were studied. The corresponding ester and oxazoline deriv
atives exhibit a moderate solvatochromism, which is caused by the donor-acc
eptor interplay, The fluorescence band shift and intensity of oxazoline If
may be reversibly modulated by protonation or complexation with silver ions
; thus, the oxazoline heterocycle serves as a useful substituent with switc
hable acceptor strength.