Synthesis and photophysical properties for fluorescent hexameric metallomacrocycles: Zinc(II)-mediated self-assembly of bis(terpyridine) ligands

Two types of hexameric metallomacrocycles, [Zn6(1)6(PF6)12] and [Zn6(2)6(PF6)12], where 1 is 1,3-bis(2,2′:6′,2″-terpyridine)-5-tert-butylbenzene and 2 is 1,3-bis(2,2′:6′,2”-terpyridinylethynyl)-5-tert-butylbenzene, were self-assembled by capitalizing on terpyridine–Zn(II)–terpyridine connectivity. Their structural compositions were established by 1H and 13C NMR, UV–Vis, and mass spectrometry. Incorporation of an ethynyl group in the metallomacrocycle can play a role as an electron trapping site to enhance the molar extinction coefficiency and photocurrent generation.