Heterometallische Verbindungen. Darstellung und Strukturen einiger Co(III)-Komplexe mit CrO4 2--Liganden / Heterometallic Compounds. Preparation and Structures of Some Co(III) Complexes with CrO4 2- Ligands

Abstract

Heteronuclear complexes containing Co(III) and Cr(VI) are formed on reaction of [Co(en)2(OH)(OH2)]2+or [Co(tren)(OH)(OH2)]2+ cations with CrO4 2- .Two types of com­plexes were isolated: 1.Complexes with two trans chromato ligands at Co; namely Li[Co(en)2(CrO4)2]·5H2O (1a) and K[Co(en)2(CrO4)2](1b). 2.Complexes having a cyclic structure with two CrO4 bridges between two cis-Co(en)2 or Co(tren) units, namely [Co2(en)4(CrO4)2]Cl2 (2a), [Co2(en)4(CrO4)2]Br2 (2b)and [Co2(tren)2(CrO4)2](ClO4)2(3). The molecular structures have been confirmed by X-ray methods. The molecular confor­mations adopted by the complexes in the solid state are stabilized by intramolecular hydro­gen bonds.