Methanol mediated crystal transformations in a solvatochromic metal organic framework constructed from Co(ii) and 4-(4-pyridyl) benzoate

Abstract

The structural transformations of compound 1 {[Co(44pba)2] 4·(DMF)3·(EtOH) 0.25·(H2O)4}n [44pba = 4-(4-pyridyl) benzoate] were followed during the exchange of DMF and ethanol molecules by methanol at room temperature. The new phases obtained 2 {[Co(44pba)2]·(MeOH)2.5·(H 2O)}n, 3 {[Co(44pba)2(MeOH)2] 2·(MeOH)2.5·(H2O) 2}n and 4 {[Co(44pba)2(MeOH) 2]·(MeOH)0.5·(H2O) 0.5}n were studied using differential scanning calorimetry, thermogravimetric analysis and X-ray diffraction methods. The final phase 4 reverts back to 1 upon soaking 4 in a dry DMF-ethanol mixture as evidenced by the powder diffraction data and infrared spectra. © 2013 The Royal Society of Chemistry.