K-I-induced synthesis of highly connected 3D K-I-Ln(III) heterobimetallic MOFs: temperature-dependent structure and physical properties

Four temperature-dependent K-I-induced K-I-Ln(III) heterometallic coordination polymers, {[LnK(OBA)(2)(mu(2)-OH2)]center dot 4H(2)O}(n) (Ln = Tb(1), Dy(2), H(2)OBA = 4,4'-oxybisbenzoic acid) and {[Ln(3)K(OBA)(4)(mu(2)-HCOO)(mu(3)-HCOO)(2)]center dot 2H(2)O}(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), [Ln(4)K(5)(-CO2)(16)(mu(2)-H2O)(4)], linked to each other by OBA(2-), 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, [Ln(3)K(-CO2)(6)(mu(2)-HCOO)(2)(mu(3)-HCOO)(4)], which are linked to each other by OBA(2-) 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.