A flexible MOF formed from Cu and 2,3-di-hydroxy-terephthalic acid.

Metal-organic frameworks (MOFs) are an exciting class of porous materials with applications in many fields. To find the optimal MOF for every application it is important to synthesize new materials to find those with the desirable properties. Here we present a MOF based on Cu and 2,3-di-hydroxy-terephthalate, whose structure in both fully solvated and partially desolvated forms, namely, poly[[tri-aqua-(μ-2,3-di-hydroxy-terephthalato)(μ-2,3-dioxido-terephthalato)tricopper(II)] monohydrate], {[Cu(CHO)(CHO)(HO)]·HO} , and poly[[di-aqua-(μ-2,3-di-hydroxy-terephthalato)(μ-2,3-dioxidoterephthalato)tricopper(II)] ethanol monosolvate monohydrate] {[Cu(CHO)(CHO)(HO)]·CHOH·HO} , has been solved with single-crystal X-ray diffraction. It shows one-dimensional hexa-gonal channels and a flexible behaviour in response to changes in solvation.