Sulfonic Acid Analogs of Terephthalic and Trimesic Acid as Linkers in Metal-Organic Frameworks - Synthesis of Thermally Robust MOFs

p-Benzenedisulfonic acid and 1,3,5-benzenetrisulfonic acid are prepared in an efficient and scalable two-step protocol from respective bromobenzene derivatives. These acids are used in analogy to terephthalic and trimesic acid for the formation of metal-organic frameworks with copper(II) centers. Due to the enhanced acidity of sulfonic acids, weakly basic malachite can be used as inorganic precursor material. After dehydration at about 100 degrees C, the anhydrous frameworks exhibit significantly increased thermal stability (up to 400 degrees C) relative to the commonly known carboxylate MOFs. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)