X-ray Crystal Structure of Triaquacopper(II) Dihydrogen 1,2,4,5- Benzenetetracarboxylate Trihydrate and Raman Spectra of Cu2+, Co2+, and Fe2+ Salts of 1,2,4,5-Benzenetetracarboxylic (Pyromellitic) Acid

✍ Scribed by Renata Diniz; Heitor A. de Abreu; Wagner B. de Almeida; Maria T. C. Sansiviero; Nelson G. Fernandes

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 389 KB
• Volume: 2002
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/1099-0682(200205)2002:5<1115::aid-ejic1115>3.0.co;2-g

✦ Synopsis

Some transition metal salts (Fe 2+ , Co 2+ , and Cu 2+ ) of 1,2,4,5benzenetetracarboxylic acid (pyromellitic acid) have been synthesized: hexaaquairon(II) dihydrogen 1,2,4,5-benzenetetracarboxylate (I), hexaaquacobalt(II) dihydrogen 1,2,4,5-benzenetetracarboxylate (II), triaquacopper(II) dihydrogen 1,2,4,5-benzenetetracarboxylate trihydrate (III), and triaquacopper(II) 1,2,4,5-benzenetetracarboxylate tetrahydrate (IV). Single-crystal X-ray diffraction analysis of compound III has been performed. It crystallizes in the non-centrosymmetric space group Pn with two molecules per unit cell. Cu 2+ and the ligand form an infinite linear chain. The metal atom is coordinated to five O atoms (three of the aqua ligand and two of the pyromellitate ligand) in a distorted trigonal-bipyramidal coordination. The carboxylic groups are involved in two medium intermolecular hydrogen bonds with water molecules. The O•••O distances are 2.629(5) and 2.639(5) A ˚. The absolute structure parameter shows that the