New metastable interfacial synthesis of a silver-terephthalate metal organic framework: structure, morphology and antibacterial activities

In this work, a silver terephthalate-based metal organic framework, [Ag2(BDC)]n (where H2BDC is the terephthalic acid), has been obtained by new synthetic routes using terephthalic acid and silver salts dissolved in a dimethyl sulfoxide (DMSO)/water mixture in the presence of ammonia used to stabilize silver ions and to control their availability. Fast crystal growth was obtained at the metastable interface between the DMSO/water mixture and a water layer formed upon slow water addition. Chemical and morphological properties of the obtained MOFs depend on the adopted synthesis conditions (routes a-c), but in all cases [Ag2(BDC)]n formation and growth took place by the dissolution of an ammonia hydrogen terephthalate salt. Large crystals of the ([Ag2(BDC)]n) monocline phase (named a-AgMOF) were grown through a slow (10 h) crystallization process (route a), while fast (3 h) crystallization processes (route b) lead to small size crystals with two different morphologies, named b-AgMOF....