A Salt-Like Compound Containing the Cation [Tris(1,10-Phenanthroline)manganese(II)](2+) and the Anion 3,3-Commo-Bis[η5-1,2-Dicarba-(3)-Cobalt(III)-closo-Dodecaborate](1–), [MnII(1,10-C12H8N2)3]2+{CoIII[η5-(3)-1,2-B9C2H11]2}–2: Synthesis and Study

In this paper, the results of a comparative study of a salt-like paramagnetic Mn(II) (d5) complex [MnII(1,10-C12H8N2)3]2+[CoIII(B9C2H11)2]–2 (I) against [MnII(1,10-C12H8N2)2(NCS)2]0 (II) and [MnII(1,10-C12H8N2)3]2+[B9C2H12]–2 (III) are presented. Complexes I and III were synthesized by precipitating the Mn(II) cations with the corresponding anions in the stoichiometric ratio at a pH of ∼ 4.5 and were studied by X-ray diffraction analysis on single crystals; by IR, Raman, and EPR spectroscopy; and using magnetochemical methods. The structures and crystal-chemical parameters of I at 190 and 293 K are identical. The crystals are mono-clinic; space group P21/n. Two crystallographic types of the [Co(B9C2H11)2]– anion in structure I have different conformational combinations (cisoid and transoid) of the –C2– groups in each pair of the B9C2H2–11 cluster ligands. The short contacts C–Hδ+···δ–H–B between different-type hydrogen atoms show themselves in the IR spectra. The apparent magnetic moments of the Mn(II) atom in I, II, and III at 293 K correspond to μ = 5.86 μB and do not depend on its ligand or anion environment. The temperature dependences μ = f(T) pass through a maximum at about 20 K, which suggests the occurrence of ferromagnetic exchange interactions in complexes I and III, which both contain cluster carborane derivatives with three-dimensional aromaticity.