KI-induced synthesis of highly connected 3D KI–LnIII heterobimetallic MOFs: temperature-dependent structure and physical properties

Abstract

Four temperature-dependent K^I-induced K^I–Ln^III heterometallic coordination polymers, {[LnK(OBA)₂(μ₂-OH₂)]·4H₂O}_n (Ln = Tb(1), Dy(2), H₂OBA = 4,4′-oxybisbenzoic acid) and {[Ln₃K(OBA)₄(μ₂-HCOO)(μ₃-HCOO)₂]·2H₂O}_n (Ln = Tb(3), Dy(4)), have been synthesized under hydrothermal conditions by controlling the temperature. Notably, compounds 1 and 2, consisting of an unique nine-nuclear cluster secondary building unit (SBU), [Ln₄K₅(–CO₂)₁₆(μ₂-H₂O)₄], linked to each other by OBA²⁻, can be simplified as a highly 12-connected three-dimensional (3D) network with fcu topology. Comparably, compounds 3 and 4 consist of a rare four-nuclear cluster SBU, [Ln₃K(–CO₂)₆(μ₂-HCOO)₂(μ₃-HCOO)₄], which are linked to each other by OBA²⁻ resulting in a highly 10-connected tcg topology. The luminescent properties of 1 and 3 were studied and the solid-state magnetic measurements reveal antiferromagnetic behaviors of 2 and 4.