A Distinct Tetradentate N2O2-type Ligand: (o-Carboranyl)bis(2- hydroxymethyl)pyridine

Abstract

A new chiral racemic ligand (o-carboranyl)bis(2-hydroxymethyl) pyridine oCB(hmpH)2, that is composed of a central o-carborane unit where two arms radiate out of the cluster carbons each one containing a 2-pyridylmethylalcohol chelating arms, provides two potentially bidentate {NO} or one tetradentate {N2O2} binding pockets. An unprecedented octahedral CoII complex CoCl2(antioCB( hmpH)2] was obtained under aerobic conditions and characterized by X-ray crystallography as well as IR and NMR spectroscopy. anti-oCB(hmpH)2 acts as a tetradentate N2O2-ligand affording the complex as a racemic mixture of cis-alpha-DELTA-[CoCl2(RR-antioCB(hmpH)2)] and LAMBDA-[CoCl2(SS-anti-oCB(hmpH)2)]. The new ligand oCB(hmpH)2 appears to be suitable for producing a variety of new chiral-at-metal complexes.