Catalytic "triangles": binding of iron in task-specific ionic liquidsElectronic supplementary information (ESI) available: Synthetic protocols, thermal TG/DSC analysis and fragments of molecular structures. CCDC 896157-896162 (1-6). For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c2cc36741f

A new class of task-specific ionic liquids (ILs) which contain septuply positively charged {Fe 3 III O(RCOO) 6 L 3 } 7+ triangles has been synthesized and structurally characterized. Such metal-containing ILs can be repeatedly used as alternative catalysts in the synthesis of 2-pyrrolo-3′-yloxindole or the condensation of indoles with various aldehydes. A new class of catalytically active task-specific ionic liquids with antiferromagnetically coupled {Fe 3 III O(RCOO) 6 L 3 } 7+ cations has been synthesized and structurally characterized.