Two microporous metal-organic frameworks with different topologies constructed from linear trinuclear M-3(COO)(n) secondary building units

Two new microporous metal-organic frameworks, [Zn-3(NH2BDC)(3)(H2O)(2)]center dot 5DMF (1) and (Me2NH2)(2)[Cd-3(NH2BDC)(4)]center dot 2DMF center dot 2.5 H2O (2) (NH2BDC = 2-amino-1,4-benzenedicarboxylate), based on linear trinuclear secondary building units of Zn-3(COO)(6) or Cd-3(COO)(8) that have different connected numbers, have been synthesized and characterized, which exhibit usual pcu and rare hex-like topologies, respectively. Both 1 and 2 are three-dimensional porous frameworks, having solvent accessible volumes of ca. 53 and 39%, respectively. There are unremovable guest Me2NH2+ cations clogged in the channels of 2. In contrast, being of good thermo-stability, 1 has a Langmuir surface area about 570 m(2) g(-1) and type I isotherm behaviour for nitrogen gas sorption at 77 K, being typical of microporous material.