Theoretical Study Of β-Diketiminate Zinc Complexes

The compounds formed with transition metal andβ-diketiminate ligands are important in research of organometallic chemistry.β-diketiminate ligands can regulate metal center on stereo and electronic effects. Therefore, the studies of the compound have obtained much efficient catalysts.In this paper, a series ofβ-diketiminate complex structures have been optimized in the B3LYP level and an appropriate basis set selected. In the same level, natural bond orbital (NBO) analysis has been applied in the optimized structure of compounds. On the equilibrium geometries, the charge density topological analysis of critical points has been achieved. In addition, the dissociation-energy of related compounds has been calculated.For RM(μ-X)₂Li(OEt₂)₂(R=[{(C₆H₃)N(Me)C}₂CH]) compounds containing different transition metals (X = I; M = Cu, Zn, Cd) and different halogen (X = Br, Cl, F; M = Zn), the study shows that Zn-Xbond order and stabilization are reduced with decrease of the halogen radius, Zn-Li and Zn-X distance, in the condition of containing different halogens, same transition metal Zn compound. Charge of Zn and X, binding energy and stability increase gradually. In the condition of containing same halogen I, different transition metal, it is not obvious difference between Zn and Cd. However, Cu compound which lacks valence electron has small binding energy. The order of charge at M is Cu 2ZnL(L={HC(CMeNPh)₂}) containing different bridged groups (X=F, OH, NH₂, Cl, SH, PH₂), the study shows that the stability of bridged four-membered ring gradually increases in ascending order, i.e., F 2 and Cl 2. PH₂ coordination compound has a stronger electronic donor-accept function with low charges. Meanwhile, PH₂ coordination compound has the higher stability energy than others. And, it also has a higher Wiberg bond order than others. Thus, bridge bond is relatively stable in this compound.This paper also has optimized RZn-ZnR(R=[{-PhN(Me)C}₂CH]) coordination compound and HC(CMeNAr)₂Zn(μ-H)₂BH₂ coordination compound. Then, these compounds are analyzed in terms of Natural Bond orbital analysis(NBO) and atom in molecular analysis(AIM). The above analysis indicates that both of these compounds stay in stable structures.