6533b7ddfe1ef96bd12746bf

RESEARCH PRODUCT

A new mixed-valence hexanuclear cobalt complex, [Co4IICo2III(dea)2(Hdea)4)(piv)4](ClO4)2·H2O: Synthesis, crystal structure and magnetic properties

Marius AndruhFrancesc LloretVioleta TudorVlad LupuAugustin M. MadalanMiguel Julve

subject

DiethanolamineValence (chemistry)Pivalic acidchemistry.chemical_elementCrystal structureInorganic ChemistryPerchloratechemistry.chemical_compoundCrystallographyBipyramidchemistryMaterials ChemistrySinglet statePhysical and Theoretical ChemistryCobalt

description

A new Co II /Co III hexanuclear complex, [Co 4 II Co 2 III (dea) 2 (Hdea) 4 )(piv) 4 ](ClO 4 ) 2 ·H 2 O 1 , has been obtained by reacting cobalt(II) perchlorate, diethanolamine, and pivalic acid (H 2 dea = diethanolamine and piv = pivalato anion). The cobalt ions are held together by four μ 3 and four μ 2 alkoxo bridges as well as by four syn – syn carboxylato groups. The hexanuclear motif contains four Co(II) and two Co(III) ions. The {Co II 4 Co III 2 (μ 2 -O) 4 (μ 3 -O) 4 } core can be described as a four face-sharing monovacant and bivacant distorted heterocubane units. The cobalt(III) ions are hexacoordinated. Two of the cobalt(II) are hexacoordinated, while the two others are pentacoordinated with a bipyramidal stereochemistry. The magnetic properties of 1 have been investigated in the temperature range 1.9–300 K. Compound 1 exhibits an overall antiferromagnetic behaviour with a ground singlet spin state.

https://doi.org/10.1016/j.ica.2009.12.006