Synthesis and Crystal Structures of New Potassium Fluorotrifluoroacetatometallates: K n[M3(µ3-F)(CF3COO)6L3]L' (M = Co, Ni; L = CF3COO^–, CF3COOH, H2O; L' = CF3COOH, H2O; n = 1, 2)

Four new representatives of potassium fluorotrifluoroacetatometallates are synthesized and crystallographically studied: K2[Co3(µ3-F)(CF3COO)6(CF3COO)(CF3COOH)2]·CF3COOH (I), K[Co3(µ3-F)(CF3COO)6(H2O)3]·H2O·2CF3COOH (II), K[Ni3(µ3-F)(CF3COO)6(H2O)3]·H2O·2CF3COOH (III), and K2[Ni3(µ3-F)(CF3COO)6(CF3COOH)3][Ni3(µ3-F)(CF3COO)6(CF3COOH)2(H2O)]·CF3COOH (IV). All complexes under study contain trinuclear triangular complex anions [M3(µ3-F)(CF3COO)6(L)3]n– (M = Ni, Co; L = CF3COO–, CF3COOH, H2O; n = 1, 2) resembling in structure the earlier studied fluorotrifluoroacetatometallates of alkaline metals and ammonium. The µ3-bridging F atom is localized at the center of the triangle of the Ni(II) or Co(II) atoms. Six bridging trifluoroacetate groups arranged above and under the plane of the [M3F] triangle pairwise bind the metal atoms. The oxygen atoms of ligands L supplement the coordination environment of the M atoms to the octahedral environment. The possibility of the charge –2 on the complex anion [M3(µ3-F)(CF3COO)6L3] is shown. The consecutive replacement of the axial molecules of trifluoroacetic acid by water changes the type of the structure from the chain (IV) to layered (II, III) structure and then to the volume network (I). The molecular structures of complexes I–IV are determined by X‑ray structure analysis (CIF files CCDC nos. 2010760 (I), 2010761 (II), 2010762 (III), and 2010763(IV)).