On the Structure of Polymeric Composite of Metallacarborane with Poly(ethylene oxide)

We studied a structure of polymeric composite based on spontaneous precipitation of sodium [3-cobalt(III) bis(1,2-dicarbollide)], NaCoD, with poly(ethylene oxide), PEO, in salted aqueous solutions. Although the solid nanocomposite, which can be considered as a homogeneous matter, cannot form monocrystals due to the high flexibility of PEO chains, we can characterize the PEO/NaCoD structure by means of solid state NMR spectroscopy, from WAXS reflections and with help of already published structures of related systems. It indicates that the layered structure of solid NaCoD and the helical crystalline structure of PEO have disappeared after their mutual interaction. The NMR results clearly show that CoD- anions are regularly dispersed within the PEO matrix, which consists of two distinct types of polymeric chains: one part interacting with dicarbollide clusters and the second one acting as a ligand of sodium counterions that also form regular pattern within the composite.