The (cAAC)2Mn complex (cAAC=cyclic alkyl(amino)carbene) features a linear two-coordinate Mn-center. The antiferromagnetic coupling of a radical electron, delocalized on two carbene C-atoms, with the central MnI having d6 electronic configuration, mainly contributes to the S T=3/2 ground state. Treatment of (cAAC) 2Mn with H2 at RT resulted in the addition of H-atoms at both "carbene" C-atoms, leaving the central Mn-atom in the S T=5/2 spin ground state.