Acid Co(II) and Ni(II) trifluoroacetate complexes: Synthesis and crystal structure

Abstract

Anhydrous and partially hydrated acid trinuclear trifluoroacetates of divalent transition metals of the composition [M3(CF3COO)6(CF3COOH)6)](CF3COOH) and [M3(CF3COO)6(CF3COOH)2(H2O)4)](CF3COOH)2, respectively, where M = Co (I, III) Ni (II, IV), were synthesized and studied by X-ray diffraction. Complexes I and II were obtained by crystallization from solutions of M(CF3COO)2 · 4H2O in trifluoroacetic anhydride; complexes III and IV were synthesized under the same conditions with the use of 99% trifluoroacetic acid as a solvent. Crystals I are triclinic: space group $$P\bar 1$$ , a = 13.199(6) A, b = 14.649(6) A, c = 15.818(6) A, α = 90.04(4)°, β = 114.32(4)°, γ = 108.55(4)°, V = 2611.3(19) A3, Z = 2, R = 0.0480. Crystals II are trigonal: space group $$R\bar 3$$ , a = 13.307(2) A, c = 53.13(1) A, V = 8148(2) A3, Z = 6, R = 0.1112. Crystals III are triclinic: space group $$P\bar 1$$ , a = 9.001(8) A, b = 10.379(9) A, c = 12.119(9) A, α = 83.67(5)°, β = 72.33(5)°, γ = 83.44(5)°, V = 1068.3(15) A3, Z = 1 A, R = 0.1031. Crystals IV are triclinic: space group $$P\bar 1$$ , a = 9.121(18) A, b = 10.379(2) A, c = 12.109(2) A, α = 84.59(3)°, β = 72.20(3)°, γ = 82.80(3)°, V = 1080.94(40) A3, Z = 1, R = 0.0334.