The 3D Channel Framework Based on Indium( <scp>III</scp> )–btec, and Its Ion‐Exchange Properties (btec = 1,2,4,5‐Benzenetetracarboxylate)

Hydrothermal reactions of InCl3 with pyromellitic dianhydride and pyridine derivatives produce three coordination polymers: {(HL)[In3(btec)2(OH)2]·L}n [btec = 1,2,4,5-benzenetetracarboxylate, L = 2-picoline (1), L = 4-picoline (2)] and {(Hdpea)[In3(btec)2(OH)2]}n [dpea = 1,2-bis(4-pyridyl)ethane] (3). Single crystal X-ray diffraction and powder X-ray diffraction analyses reveal that compounds 1–3 are isostructural and possess the same 3D framework as 1D open channels. Thermal gravimetric studies show that compounds 1–3 are stable up to 300 °C. The guests of the protonated pyridine derivatives located at the channels in 1 and 2 can be fully exchanged by Ca2+ and Ba2+ ions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)