Synthesis, structures and properties of ironIII complexes with (o-carboranyl)bis-(2-hydroxymethyl)pyridine: Racemic versus meso

摘要

The reaction of iron(II) chloride with anti- or syn-1,2-bis{(pyridin-20-yl)methanol}-1,2-dicarba-closododecaboraneud(anti- or syn-oCB-L1) afforded two new complexes, [Fe2Cl2(anti-oCB-L12 )2] (1) orudFe2Cl3(syn-oCB-L12 )(EtO)(H2O) (2), respectively. Both complexes were unambiguously characterizedudby means of X-ray structure analysis. Their solid state structures give evidence for the different coordinationudmodes of the ligands. Both compounds are dinuclear FeIII complexes, however, whereas in complexud1 there are two anti-oCB-L12 ligands per molecular unit, in complex 2 only one syn-oCB-L12 isudfound. In complex 1, anti-oCB-L12 acts as a tetradentate N2O2-ligand affording a homochiral complexudas a partial racemic mixture of D,D-[Fe2Cl2(RRanti-oCB-L12 )2] and K,K-[Fe2Cl2(SSanti-oCB-L12 )2]. Inudcomplex 2, syn-oCB-L12 behaves as a bis-bidentate NO ligand. Only complex 1 could be synthesizedudin good yield and as a pure phase and it has been therefore fully characterized by spectroscopic methodsudand the magnetic properties studied.