Hydrogenative Depolymerization of Polyurethanes Catalyzed by a Manganese Pincer Complex.

Chemical recycling, in particular hydrogenative depolymerization, offers a promising way to utilize plastic waste. This report covers the manganese-catalyzed hydrogenation of polyurethane materials to the corresponding monomeric units. The key to success is a Mn pincer complex as a potent hydrogenation catalyst in combination with elevated temperatures (up to 200 °C) and appropriate solvents to ensure sufficient solubility of the polymers. A wide range of polyurethane samples of varying polyol and isocyanate compositions, some of which feature significant amounts of urea functionalities, are depolymerized, releasing polyetherols and diaminotoluene (TDA) in yields of up to 89 % and 76 %, respectively.

Metallosupramolecular Thin Polyelectrolyte Films.

Molecular recognition and electrostatic interaction of oppositely charged polyelectrolytes are combined in the fabrication of ultrathin metallosupramolecular multilayers [shown schematically in the picture, PEI=polyethyleneimine, PSS=poly(styrene sulfonate)]. The layers between the PSS layers are composed of an iron(II) bis(terpyridine) coordination polymer.