Structure of {[η~5-C_5H_5)_2Zr(μ-P(C_6H_5))]_2}{[(THF)_3Li]_2(μ-Cl)} and Its Implications for the Nature of Dilithium Dinitrogen Complex

摘要

X-ray structure of the complex salt {[Cp_2Zr(μ-PPh)]_2}{[(THF)_3Li]_2(μ-Cl)}, 1, as well as its EPR spectrum and magnetic susceptibility have been investigated. The results indicate that the anionic part of the complex is the mixed valence [Zr(Ⅲ)Zr(Ⅳ)] monoanion. From the comparison of the complex 1 and dinitrogen complex {[Cp_2-Zr(μ-PPh)]_2}{[(THF)_3Li]_2(μ-N_2)}, 2, published elsewhere it follows that the anions of both the complexes are identical and therefore the cation of 2 has also a unit charge, it is concluded that the cation {[(THF)_3Li]_2(μ-N_2)}~+ can be regarded as a complex of N_2 with the pair (Li···Li)~+ or that of N_2~- stabilized by two Li~+ cations. Theoretical grounds for the existence of such complex ion are discussed.