High-Temperature Reactions of Metal Triangles: The Influence of Counterion, Ligand, and Metal on the Structure Observed

A series of oxo-centered metal carboxylate triangles have been heated to 200–400°C under a stream of N2. The products of this treatment depend on the metal, carboxylate, and counterion present. Heating [Cr3O(O2CC6H4Cl)6(H2O)3][NO3]to 200°C gives a compound that crystallizes as [Cr(OH)(O2CC6H4Cl)2]8 [Cr3O(O2CC6H4Cl)6]2[O2CC6H4Cl], indicating incomplete dehydration of [Cr3O(O2CC6H4Cl)6(H2O)3][NO3] at this temperature. For [Cr3O(O2CCMe3)6][O2CCMe3] heating to 400°C gives a new salt containing the hexanuclear cages [Cr6O2(OH)2(O2CCMe3)11] [Cr6O4(O2CCMe3)11]. For [Mn3O(O2CPh)6(NC5H5)2(H2O)] a reduction of the metal occurs and a polymeric complex [Mn4(O2CPh)8(EtOH)6]n can be crystallized from EtOH.