Attempts to directly synthesize low-valent dinuclear cobalt complexes, by reacting the PNNP ligand with low-valent cobalt(I) precursors such as CoCl(PPh 3 ) 3 and Co(PMe 3 ) 4 24 , led to intractable mixtures. Therefore, we decided to attempt the synthesis of a cobalt(II) parent compound, which could then be reduced to obtain the desired low-valent cobalt species. The reaction of 1 eq tBu PNNP ligand with 2 eq of CoCl 2 (THF) 1.5 (Scheme 2) in THF led to the formation of a bright blue paramagnetic precipitate, which was characterized as complex 1 and isolated in 99% yield. Complex 1 does not dissolve in ethereal or apolar solvents, but readily dissolves in dichloromethane (DCM). The paramagnetic 1 H NMR spectrum of 1 in DCM-d 2 at 298 K features broad peaks in the range of 118.47 to -33.47 ppm. There are 7 distinguishable peaks that integrate to one proton each, indicating a non-symmetric complex. There are two signals integrating to ~9 protons, and one that integrates to 18 protons, meaning that two of the tBu-groups of the ligand are magnetically inequivalent. This is consistent with the observation of more than 6 peaks for the naphthyridine backbone and it indicates that both the C 2 and C S symmetry of the ligand is no longer present in complex 1.