Magnetic Properties of bis-o-Benzosemiquinonato Cobalt(II), Iron(II), and Manganese(II) Complexes with 2,2'-Biquinoline and 1,4-Di-tert-Butyl-1,4-Diazabutadiene

New heteroligand cobalt(II), iron(II), and manganese(II) complexes of the M(3,6-SQ)2L type bearing 3,6-di-tert-butyl-o-benzosemiquinonato ligands (3,6-SQ) and 2,2'-biquinoline or 1,4-di-tert-butyl-1,4-diazabutadiene-1,3 as neutral ligands (L) have been synthesized and characterized. It was shown on the basis of the magnetic susceptibility measurements and spectroscopic studies that all complexes contain metal(II) ions in the high-spin state and two radical-anionic o-semiquinonato ligands. It was found in the result of analysis of magnetic susceptibility temperature dependence by magnetic coupling parameters modeling that the antiferromagnetic ligand-ligand coupling takes place in the cobalt(II) and iron(II) complexes, while antiferromagnetic metal-ligand interactions dominate in the manganese(II) complexes.