Evidence of an Unexpectedly Long C-C Bond (>2.7 Å) in 1,3-Metalladiyne Complexes [Cp2MCCR]2 (M = Ti, Zr): QTAIM and ELF Analyses

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• 作者：Isaac Vidal ; Santiago Melchor ; Jos&eacute ; A. Dobado
• 刊名：Journal of Physical Chemistry A
• 出版年：2008
• 出版时间：April 17, 2008
• 年：2008
• 卷：112
• 期：15
• 页码：3414 - 3423
• 全文大小：594K
• 年卷期：v.112,no.15(April 17, 2008)
• ISSN：1520-5215

文摘

Topological analyses of the electron density using the quantum theory of atoms in molecules (QTAIM) andelectron localization function (ELF) have been carried out, at the B3LYP/DGVZVP and MP2/DGVZVPtheoretical levels, on different 1,3-metalladiyne cyclic compounds [Cp₂M(CCR)]₂, (M = Ti, Zr; R = F, CH₃,H, SiH₃). The QTAIM results indicate the presence of an extraordinarily long C-C bond (in a 2.7-3.0 Årange) connecting the CCR moieties, contrary to the common geometrical assumption of a M-M bond insimilar metallacycles. The existence of this C-C bond is also supported by the distinct consequences on thereaction profiles for the Ti and Zr complexes, the CC oxidative coupling reactions being favored only for theTi complexes. Moreover, the consequences of this bonding in the coupling/cleavage reactions of thesemetallacyclic complexes are reported and analyzed, revealing the transcendence of these long-range bonds inthe overall behavior of these compounds.