Theoretical Study on N-N Activation by Thiolate-bridged Dinuclear Dinitrogen Transition-metal Complexes

90 kinds of dinitrogen binuclear transition-metal complexes at singlet and triplet states in Group 4 similar to 10 from Period 4 to 6 based on the biomimetic dinitrogen fixation species were studied using DFT method, [Cp*Fe(mu-eta(2):eta(2)-bdt)-(mu-eta(1):eta(1)-MeN=NMe)FeCp*] and [Cp*Fe(mu-SEt)(2)(mu-eta(1):eta(1)-MeN=-NMe)FeCp*], in order to investigate the transition-metal effect in N-N activation. The calculated results indicate that N-N bond activation is strongly related to the period of transition metal. N-N activation by transition metals in Period 6 is stronger than those in Period 5 and Period 4. For transition metals in the same period, N-N activation ability decreases from Group 4 to Group 10. The odd-even electron number of transition metal center also shows certain influence on the N-N activation. In addition, side-on coordination mode is more favorable than end-on mode for thiolate-bridged dinuclear transition-metal complexes on N-N bond activation. The type of ligands (BDT ligand or ethyl ligand) in this system has little impact on N-N activation.