Three pillared-layer 3d-4f heterometallic frameworks based on tetranuclear lanthanide clusters

Three 3D heterometallic 3d-4f MOFs, formulated as [Gd₄L ₁₂(Cu₁₀I₈)(H₂O)₁₀] ·2ClO₄·4H₂O (1), [La₄(Ox) ₂L₈(Cu₇I₅)(H₂O) ₄]·2ClO₄·4H₂O (2), and [La ₄Na(Ox)₃L₈(Cu₇I₆)(H ₂O)₃]·5H₂O (3) [where Ox = oxalate, HL = 4-pyridin-4-ylbenzonic acid], have been made under hydrothermal conditions. All the MOFs are characterized by elemental analysis, IR, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction. These novel 3D pillared-layer frameworks are constructed from 2D lanthanide-organic layers based on tetranuclear lanthanide clusters, and pillared by diverse copper(i) halide motifs. The oxalate is introduced as a coligand to make the hook-like tetramer in compound 1 into compact butterfly-like tetramer in compounds 2 and 3 due to its size preference.