• catalisi omogenea
• homogeneous catalysis
• hydrogen
• idrogeno
• leganti chelanti
• manganese
• pincer ligands

A dearomatized Mn-PNP complex was prepared by the reaction of the corresponding aromatic complex with t-BuOK in THF. This new dearomatized complex was fully characterized and the molecular structure was further confirmed by X-ray crystallography. A distorted square-pyramidal geometry around the manganese center was observed, with a CO ligand in trans to the pyridinic nitrogen atom and the other in the apical position. The complex displays efficient catalytic activity for formic acid dehydrogenation under mild conditions in DMSO. Mechanistic studies suggest that the imine arm participate in the formic acid activation/deprotonation, showing another example of metal-ligand cooperativity in this type of chelated complexes.