Synthesis and structural analysis of titanium-μ-dinitrogen complex supported by di-anionic guanidinate ligands

The synthesis, characterization, and theoretical studies of titanium-μ-N2 complexes with di-anionic guanidinate ligands were reported as the first example of its kind. Thus, with (Me3Si)2N-guanidinate ligands, the mono-anionic guanidinate-supported titanium-μ-N2 complex 1 was obtained. Then, reduction of 1 with potassium afforded the di-anionic guanidinate-supported titanium-μ-N2 complex 2 via cleavage of one N—Si bond of the (Me3Si)2N substituents in 1, changing the guanidinate ligands automatically from mono-anionic to di-anionic and remarkably lengthening the bond length of the µ-N2. Characteristic studies and DFT calculations were performed to reveal that the di-anionic guanidinate ligands stabilized the geometry of 2 and increased the charge density on the bridging dinitrogen.