Heteroatom-Modulated Assembly of Hexalanthanoid-Containing Polyoxometalate-Based Coordination Networks.

Two series of lanthanoid (Ln)-containing polyoxometalates (POMs) {[Ln(ampH)(HO)(ampH)(PWO)]·21HO (Ln = Tb, = 0 (), Ln = Er, = 1 ()) and K[Ln(ampH)(HO)(SiWO)]·23HO (Ln = Tb (), Er ()) (ampH = (aminomethyl) phosphonic acid)} have been synthesized with tri-lacunary Keggin-type POMs containing different types of heteroatoms. Compounds and display neutral organic-inorganic hybrid POM molecules containing {Ln(ampH)} ({Ln}) cores sandwiched by two {PWO} units. By changing the heteroatoms from P to Si, the extended 2D networks of and were successfully isolated where the adjacent {Ln} clusters were connected by {SiWO} moieties. Luminescence performances and magnetic properties of have been systematically surveyed. The solid-state fluorescence spectra of display characteristic emissions of Ln components resulting from the 4f-4f transitions, and energy transfer from the POM segments to Ln centers in and has been observed based on the lifetime decay behaviors. Furthermore, all compounds can be utilized as electrocatalysts toward reduction of nitrite with high stability.