Crystal and molecular structure of potassium [Δ,Λ-racemic-(1-phenylethylenediamine-N,N,N',N'-tetraacetato)cobaltate(III)] sesquihydrate

Abstract

The crystal and molecular structure of the title compound was determined by X-ray analysis. It crystallizes in the orthorhombic system, space group Ccc2, with cell parameters a = 3.773(3), b = 1.404(11), c = 0.6962(6) nm, V = 3.687 nm3, and Z = 8. The main factors determining stereochemistry of the complex are intramolecular hydrophobic stacking interaction between the methylene hydrogens of the out-of-plane R1 ring and the aromatic ring of the phenyl group, and the nonbonding van der Waals interactions between the methylene hydrogens of the central ethylenediamine (E), in-plane glycinate (G) and R rings as well as of the hydrogens of the phenyl group. The observed stereospecific coordination is due to an energy preference for the equatorially located phenyl group on the E ring.