Synthesis and Structure of [М(DMF)6][B10H10] (M = Zn(II), Cd(II)) as Precursors for Solid-Phase Synthesis of Trischelate Complexes [М(L)3][B10H10]

Abstract

The reactivity of the decahydro-closo-decaborate anion in the complexation of metals being among intermediates acids in the concept of the Pearson’s theory of hard and soft acids and bases is studied systematically in the presence of competitive ligands L. In continuing these studies, we have synthesized Zn(II) and Cd(II) complexes of the composition [М(DMF)₆][B₁₀H₁₀] (M = Zn(II), Cd(II)) and studied them by physicochemical analyses (IR and UV spectroscopy, X-ray powder diffraction). The possibility of their use in solid-phase synthesis of the corresponding trischelate complexes [M(Bipy)₃][B₁₀H₁₀] has been found. Complexes [М(DMF)₆][B₁₀H₁₀] are formed by the reaction between triethylammonium closo-decaborate with metal nitrates in DMF. The compounds are isostructural with the corresponding Co(II) and Ni(II) complexes [М(DMF)₆][B₁₀H₁₀]. Specific interactions have been found between the BH groups of the boron clusters and CH groups of the DMF molecules. According to the data of IR and UV spectroscopy, the complexes contain specific B–H···C–H interactions. The corresponding tris-chelate complexes of the metals [M(Bipy)₃][B₁₀H₁₀] are also isostructural.