Luminescent phosphinocrown-containing gold(I) complexes: Their syntheses, spectroscopic studies and host–guest chemistry

A series of phosphinocrown ether-containing gold(I) complexes, [Au(Ph2P-b15c5)Cl] (1), [Au2(μ-i-mnt)(Ph2P-b15c5)2] (2) and [Au2(μ-dtc)(Ph2P-b15c5)2](PF6) (3) (b15c5 = benzo-15-crown-5, i-mnt2− = 1,1-dicyanoethylene-2,2-dithiolate, dtc− = diethyldithiocarbamate) have been synthesized. Complexes 2 and 3 · NaPF6 have also been structurally characterized. The emission bands at ca. 500–515 nm for 2 and 3 upon photo-excitation are tentatively assigned as derived from excited states of S → Au ligand-to-metal charge transfer (LMCT) origin. These complexes have been shown to serve as host for the specific binding of various metal cations.