Previously, quinolinium-based tetraazacyclophanes, such as UCL 1684 and UCL 1848, have been shown to be extraordinarily sensitive to changes in chemical structure (especially to the size of the cyclophane system) with respect to activity as potent non-peptidic blockers of the small conductance Ca2+-activated K+ ion channels (SKCa). The present work has sought to optimize the structure of the linking chains in UCL 1848. We report the synthesis ...