Electronic structure of the 3,3′-bis-[η5-π-1,2-dicarba-3-nickel(III)-closododecaborate](1-) anion, {NiIII[η5-π-(3)-1,2-B,C2H11]2}, in salts with different cations,in salts with different cations

The results of the spectral and magnetochemical studies of some salts of the “sandwich-like” paramagnetic anion {Ni^IIIη⁵-π-(3)-1,2-B⁹C₂H₁₁]₂}^– (I) with the Cs⁺, (CH₃)₄N⁺, and (C₆H₅)₄P⁺ cations and the cation complex of Fe(II) and 1,10-phenanthroline, Fe^IIPhen₃]²⁺, are reported. The solid-phase IR, Raman, and X-ray photoelectron spectroscopy methods and optical spectroscopy of solutions were used. The effective magnetic moments (μ_eff) of Ni(III) in anion (I) were measured by the Faraday technique and corrected for the diamagnetism of the aromatic cluster ligands 1,2-B₉C₂H ₁₁ ²⁻ (II). It is established that μ_eff is weakly dependent on the nature of the cation. The problems concerned with the nature of the metal-ligand bonds in metal-carborane systems like (I) are discussed. The hypothesis of the charge transfer from ligands (II) to the transition metal atoms is validated, the donor ability rows of the π-ligands are introduced, and the cluster structure of the systems under study is attested. Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 6, pp. 1060–1071, November–December, 1996. Translated by I. Izvekova