Search

In this paper, two 3D anionic metal-organic frameworks, [(CH3CH2)2NH2]·[Zn(BTC)1/3(PyC)]·1/2CH3CN·2H2O (NKU-102) and [(CH3CH2)2NH2]·[Zn2(BTC) (PyC)]·1.5H2O·DEF (NKU-103), were constructed from the same reaction system at different temperature. Though both are of anionic framework, NKU-102 possesses a sealed 3D framework based on octahedral cage and shows negligible adsorption capacity of organic dyes, whereas NKU-103 features an open triangular microchannel surrounded by two types of helical chains, and thus exhibits outstanding size-selective adsorption toward small cationic organic dyes. [ABSTRACT FROM AUTHOR]

By assembling CoII ions and a combination of 5-(4-pyridyl)tetrazole (4-ptz) and formate ions, two distinct metal-organic frameworks, [Co3(4-ptz)5(HCOO)(H2O)2] and [Co3(4-ptz)4(dmf)2(HCOO)2 ] (dmf= N, N′-dimethylformamide), were synthesized. They were both characterized by single-crystal X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and powder X-ray diffraction. Structural analyses revealed that by slightly modulating the coordination environment of the trinuclear cobalt cluster, two complexes were formed featuring unusual six-connected nets reminiscent of a pyrazole-type linear trinuclear cobalt cluster as compared with the classic eight-connected bcu topology. In addition, [Co3(4-ptz)5(HCOO)(H2O)2] interacted strongly with CO2, with an adsorption enthalpy of 29.2 kJ mol−1, and in a selectivity study, the uptake ratios of CO2/N2 (from a 15:85 mixture) and CO2/CH4 (50:50 mixture) were 77.6 and 37.7, respectively. Magnetic studies on both complexes revealed weak antiferromagnetic coupling between the CoII ions. [ABSTRACT FROM AUTHOR]