Structure of a FeO-Heteraadamantane-Type Hexacation Stabilized by Chelating Organophosphine Oxide Ligands.

Metal-containing heteraadamantanes are compounds of interest due to their spectroscopic and magnetic properties, which make them promising materials for non-linear optics and semiconductors. Herein we report the comprehensive structural characterization of a new coordination compound of the formula (-OH')(OH″)(O = P(Ph)CHCH(Ph)P = O){Fe(-BuOH)}(Cl) with the chelating ligand PhP(O)-CHCH-P(O)Ph. The compound crystallizes as a polynuclear metal complex with the adamantane-like core [FeO] in the space group -43d of a cubic system. The single-crystal XRD analysis showed that the crystal contains one symmetrically independent octahedrally coordinated Fe atom in the oxidation state +3. The adamantine-like scaffold of the Fe complex is formed by hydroxy bridging oxygen atoms only. Hirshfeld surface analysis of the bridging oxygen atoms revealed two types of -OH groups, which differ in the degree of exposure and participation in long-range interactions. Additionally, the Hirshfeld surface analysis supported by the enrichment ratio calculations demonstrated the high propensity of the title complex to form C-HCl, C-HF and C-HO interactions.