Crystal structure of the inverse crown ether tetrakis[μ2-bis(trimethylsilyl)amido]-μ4-oxido-dicobalt(II)disodium, [Co2Na2{μ2-N(SiMe3)2}4](μ4-O)

Abstract

The title compound, [Co2Na2{μ2-N(SiMe3)2}4](μ4-O), (I), represents a new entry in the class of inverse crown ethers. In the molecule, each Co atom is formally in the oxidation state +II. The structure contains one half of a unique molecule per asymmetric unit with the central μ4-oxido ligand residing on an inversion center, leading to a planar coordination to the Na and Co atoms. In the crystal, bulky trimethylsilyl substituents prevent additional interactions with cobalt. However, weak intermolecular Na...H3C—Si interactions form an infinite chain along [010]. The structure is isotypic with its Mg, Mn and Zn analogues.