Crystal structure of ammonium/potassium trans-bis(N-methyliminodiacetato-κ3O,N,O′)chromate(III) from synchrotron data

• Main Authors: Dohyun Moon, Jong-Ha Choi
• Format: Article
• Language: English
• Published: International Union of Crystallography 2016-08-01
• Series: Acta Crystallographica Section E: Crystallographic Communications
• Subjects: crystal structure; synchrotron radiation; ammonium/potassium salt; bis(methyliminodiacetato)chromate(III) ion; mida; trans-facial configuration; hydrogen bonding
• Online Access: http://scripts.iucr.org/cgi-bin/paper?S2056989016011804

The structure of the title compound, [(NH4)0.8K0.2][Cr(C5H7NO4)2] (C5H7NO4 is methyliminodiacetate; mida), has been determined from synchrotron data. The CrIII atom is located on a centre of symmetry and is coordinated by two N atoms and four O atoms of two facially arranged tridentate mida ligands, displaying a slightly distorted octahedral coordination environment. The Cr—N and mean Cr—O bond lengths are 2.0792 (14) and 1.958 (14) Å, respectively. The cation site is located on a twofold rotation axis and shows occupational disorder, being occupied by ammonium and potassium cations in a 0.8:0.2 ratio. In the crystal, intermolecular hydrogen bonds involving the N—H groups of the ammonium cation as donor and the two non-coordinating O atoms of the carboxylate group as acceptor groups consolidate the three-dimensional packing.