Syntheses, crystal structures and thermal decomposition studies of two novel Mn(ii)-MOFs with tetrazole-based carboxylic acids†
Abstract
The tetrazole-based carboxylic acids can be used as difunctionalized ligands for the preparation of functional MOFs with novel topologies. Herein we chose two tetrazole-based carboxylic acids, 1,3-bis(2-carboxymethyltetrazol-5-yl)benzene (H2L1) and 2-(5-(3-pyridyl)tetrazol-2-yl)propionic acid (HL2), as ligands and synthesized two novel Mn(II)-MOFs: [Mn(L1)(DMF)(H2O)]·0.375H2O (1) and [Mn(L2)2] (2) (DMF = N,N-dimethylformamide). These MOFs have been characterized by elemental analysis, FT-IR and single crystal X-ray diffraction. MOF 1 displays a 2D network with an sql topology, while MOF 2 shows a novel binodal 5,6-connected 3D framework with the Schläfli symbol of (32·44·64)(34·46·64·7). Differential scanning calorimetry and thermogravimetric analyses were adopted to investigate the thermal decomposition processes of the MOFs and the thermodynamic parameters (ΔH, ΔS and ΔG) were obtained.