Structures and magnetic properties of new trinuclear CoII, NiII, and CuII complexes with trimethylacetate and 1,1-cyclohexanediacetate

The reactions of transition metal trimethylacetates [Cu2(Piv)4(HPiv)2], [Ni9(OH)6(Piv)12(HPiv)4], [Co(Piv)2]n (Piv− = −O2CBut) with 1,1-cyclohexanediacetic acid (H2Chda) neutralized by tetrabutylammonium hydroxide in the presence of 2,2-bipyridine (2,2′-bpy) afford linear trinuclear homometallic complexes [(2,2′-bpy)2Cu3(Chda)2(Piv)2]··2EtOH (1) and [(2,2′-bpy)2M3(Chda)2(Piv)2(EtOH)2] (M = NiII (2) or CoII (3)). In molecules of these compounds, anions of both mono- and dicarboxylic acids act as bridges between the transition metal atoms. Compounds 1–3 were characterized by X-ray diffraction, and their magnetic properties were studied. Spin-spin ferromagnetic interactions dominate in complexes 1–3 with CuII (S = 1/2) (1) and CoII (S = 3/2) (3) ions.