四重键化合物M_2(CH_3)_8^(n-)中金属—金属键的性质

THE NATRUE OF THE METAL-TO-METAL BONDS IN QUADRUPLY BONDED COMPOUNDS M_2(CH_3)_8^(n-)

本文分析了四重键化合物M_2(CH_3)_8^(n-)(M=Mo,Tc,W,Re)中金属键的性质,并对金属原子的(n-1)f轨道参加成键的可能性进行了讨论.结果表明(n-1)f轨道参加成键使金属原子间π和δ电子的几率增加,并使总能量、π和δ成键轨道能量明显下降。因此,f轨道对金属四重键特别是π和δ键的影响是显著的。

In the present paper, the nature of the metal-to-metal bonding in quadruply bonded compounds M_2(CH_3)_8^(M=Mo,Tc,W and Re)is analyzed and the possibility for the participation of (n-l)f orbitals of these metal atoms in the bond formation is studied. The results show that the participation of the f orbitals in the bond formation enhances the probability for finding π-and δ-electrons between the metal atoms and makes the total energies and the energy, levels of π-and δ-bonding orbitals decrease. Therefore, the influence of the f orbitals on the metal-to-metal quadruple bonds, especially on the π-and δ-bonds,is obvious.