Energy decomposition analysis of the metal-imine bond in [(CO)(4)M-SB] (M = Cr, Mo, W; SB: RHC=N-CH2CH2-N=CHR)

作者：Bayat Mehdi; Salehzadeh Sadegh^*; Frenking Gernot

来源：Journal of Organometallic Chemistry, 2012, 697(1): 74-79.

DOI：10.1016/j.jorganchem.2011.10.024

• Metal-Schiff base complex
• Bonding analysis
• DFT calculation

The electronic and molecular structures of the metal-Schiff base complexes [(CO)(4)M-SB] (M: Cr, Mo, W; SB: RHC=N-CH2CH2-N=CHR, R=C6H5, C6F5, Ortho-, Meta-and Para-XC6H4 (X = F, Cl, Br, CH3)) have been investigated at the DFT level using the exchange correlation functional BP86. The nature of the TM -Schiff base interactions was analyzed with charge and energy decomposition methods. The octahedral equilibrium geometries have C-2v symmetry. The (CO)(4)M-SB bond dissociation energies vary little for different substituents R. The calculated values indicate rather strong bonds which exhibit the trend for the different metals M = Mo (D-e = 59.8-65.4 kcal/mol) %26lt; Cr (D-e = 62.3-67.8 kcal/mol) %26lt; W (D-e = 69.9 -75.8 kcal/mol). The energy decomposition analysis suggests that the (CO)(4)M-SB attractive interactions come mainly from electrostatic attraction which provide similar to 60% to Delta E-int while similar to 40% come from orbital interactions. The latter term arises mainly (similar to 70%) through (CO)(4)M %26lt;- SB sigma donation from the nitrogen lone-pair orbitals while a much smaller part (similar to 20%) comes from (CO)(4)M -%26gt; SB pi backdonation. The transition metals carry large negative partial charges between -2.3 e for M = Cr and -1.1e for M = W.

• 出版日期2012-1-15