Preparation of metal-organic frameworks of different net topologies via conventional solvothermal reactions and via the combination of solvothermal reactions and postsynthetic modifications

Abstract

[Part A] Metal-organic frameworks (MOFs), [(MnⅡ3O)L3S3] (1) and [(MnⅡ5O2)L4S8] (2), were prepared using a new ligand, 2,6-di(1H-tetrazol-5-yl)naphthalene (2,6-H2NDT), in which two tetrazole units are connected via the naphthalene group. The ligands in HNDT-1/NDT2- deprotonation states offer a very rich coordination chemistry as a result of having two tetrazolate rings, each with three/four possible donor nitrogen atoms and may supply diverse coordination modes. The single crystal diffraction study reveals that 1 is constructed from a trinuclear {MnⅡ3} building-block as a 6-connected secondary building unit (SBU) and the ligand in HNDT-1 and NDT2- deprotonation states as a linker. It shows that the tetrazolate groups adopt a bidentate (1,2-μ bridging) binding mode with the MnⅡ centers in 1. The trinuclear SBU is connected to six neighboring SBUs, which can be considered a six-connected node, to form the 3D MOF of an acs net topology, 1. 2 is constructed from a pentanuclear {MnⅡ5} building-block as a SBU and the ligand in HNDT-1 and NDT2- deprotonation states. It shows that the tetrazolate groups adopt a monodentate binding mode, bidentate (1,2-μ and 2,3-μ bridging) binding modes, and a tridentate binding mode with the MnⅡ centers in 2. The pentanuclear SBU is connected to eight neighboring SBUs, which can be considered an eight-connected node, to form the 3D MOF of a bcu net topology, 2. The structural characteristics and sorption behaviors of the two MOFs of different net topologies will be discussed in the paper.