Synthesis, photophysics and binding studies of Pt(II) alkynyl terpyridine complexes with crown ether pendant. Potential luminescent sensors for metal ions

Two crown ether-containing platinum(II) alkynyl terpyridine complexes, [Pt(tpy)(C equivalent to C-benzo-15-crown-5)]OTf (1) and [Pt(tpy)(C equivalent to C-N-phenylaza-15-crown-5)]OTf (2) (tpy = 2,2':6',2 ''-terpyridine), have been synthesized and characterized. UV-vis spectrophotometric, emission and H-1 NMR titration methods were employed to investigate their ion-binding properties. Complex 1 was found to show luminescence enhancement upon binding of Mg2+ and Ca2+ ions to its crown cavity.