An unusual eight-connected self-penetrating ilc net constructed by dinuclear lanthanide building units

Abstract

Hydrothermal reactions of Ln₂(C₂O₄)₃·9 H₂O and CuCl₂·2 H₂O with pyridine-2,3-dicarboxylic acid (H₂pdc) in water in the presence of acetic acid lead to two novel three-dimensional lanthanide(III)–copper(I) heterometallic compounds: LnCu(na)₂(C₂O₄)·1.5 H₂O (Ln = La1, Ce2; na = nicotinic acid). Both compounds are isostructural and contain two distinct units of 2D Ln-organic layers and nonlinear [Cu(na)₂]⁻, the nonlinear [Cu(na)₂]⁻ act as pillars and further link the Ln-organic layers, resulting in two heterometallic metal–organic frameworks (MOFs) with two distinct types of channels along the a and c axes. Further structural analysis reveals that 1 is a scarcely reported eight-connected self-penetrating ilc net with dinuclear {Ln₂} subunits as secondary building units. Furthermore, the IR, TGA, PXRD properties were also studied.