1,4-Phenylenediacetate-Based Ln MOFs - Synthesis, Structures, Luminescence, and Catalytic Activity

A series of new isostructural lanthanide MOFs, [Ln(2)(pda)(3)-( H2O)]center dot 2H(2)O [Ln = La (1), Ce(2), Pr(3), Nd(4), Sm(5), Eu(6), Gd(7), Tb(8), Dy(9), Ho(10), Er(11), Tm(12), and Yb(13); H(2)dpa = 1,4-phenylenediacetate], have been solvothermally synthesized and structurally characterized by single-crystal (or/and powder) X-ray diffraction analysis. All the MOFs are isostructural and consist of 1D Ln-COO helixes that are cross-linked by the -CH2C6H4CH2- spacers of the pda(2-)anions in a 3D compressed honeycomb-shaped network with 1D open channels, which accommodate guest and coordinated water molecules. Evacuation of [Ln(2)(pda)(3)(H2O)]center dot 2H(2)O at 200 degrees C under vacuum generates [Ln(2)(pda)(3)], which gives X-ray powder diffraction patterns consistent with those of [Ln(2)(pda)(3)(H2O)]center dot 2H(2)O. MOFs 6 and 8 show characteristic luminescent properties. Activated [Tb-2(pda)(3)] exhibits excellent catalytic performance in the heterogeneous acetalization of benzaldehyde with methanol. The possibility for easy recycling makes this catalyst a highly promising candidate to address environmental concerns.