A bis(silylene)pyridine pincer ligand can stabilize mononuclear manganese(0) complexes: facile access to isolable analogues of the elusive d 7 -Mn(CO) 5 radical.

Using the potentially tridentate N , N' -bis( N -heterocyclic silylene)pyridine [SiNSi] pincer-type ligand, 2,6- N , N' -diethyl-bis[ N , N' -di- tert -butyl(phenylamidinato)silylene] diaminopyridine, led to the first isolable bis(silylene)pyridine-stabilized manganese(0) complex, {κ 3 -[SiNSi]Mn(dmpe)} 4 (dmpe = (Me 2 P) 2 C 2 H 4 ), which represents an isolobal 17 VE analogue of the elusive Mn(CO) 5 radical. The compound is accessible through the reductive dehalogenation of the corresponding dihalido (SiNSi)Mn(ii) complexes 1 (Cl) and 2 (Br) with potassium graphite. Exposing 4 towards the stronger π-acceptor ligands CO and 2,6-dimethylphenyl isocyanide afforded the related Mn(0) complexes κ 2 -[SiNSi]Mn(CO) 3 (5) and κ 3 -[SiNSi]Mn(CNXylyl) 2 (κ 1 -dmpe) (6), respectively. Remarkably, the stabilization of Mn(0) in the coordination sphere of the [SiNSi] ligand favors the d 7 low-spin electronic configuration, as suggested by EPR spectroscopy, SQUID measurements and DFT calculations. The suitability of 4 acting as a superior pre-catalyst in regioselective hydroboration of quinolines has also been demonstrated.