Square structures and photophysical properties of Zn(2)Ln(2) complexes (Ln = Nd, Eu, Sm, Er, Yb)

Heterotetranuclear Zn(2)Ln(2) (Ln = Nd 2, Eu 3, Sm4, Er 5, Yb 6) complexes {Zn-2(Mq)(2)(tpyO)(2)}{(Ln(hfac)(3))(2)} (HMq = 2-methyl-8-hydroxylquinoline, tpyOH = [2,2':6'2 '']terpyridin-4'-ol, hfac = hexafluoroacetylacetonate) display novel square structures ligated by bifunctional ligands tpyO (mono-and tridentate) and Mq (chelating and bridging mu-phenoxo). These compounds exhibit sensitized lanthanide emission upon photo-excitation of ZnMq/tpy antenna chromophores. By virtue of the dual luminescence with complementary colors, the ZnMq/tpyO-based cyan emission and Sm-III-centered orange luminescence are combined to generate a white-light emission in Zn2Sm2 (4) complex.