Department of Physical and Colloid Chemistry, Peoples' Friendship University of Russia, 6 Miklukho-Maklaya Street, Moscow 117198, Russian Federation.
Inorg Chem. 2012 Aug 20;51(16):8868-72. doi: 10.1021/ic300786w. Epub 2012 Jul 30.
Quantum chemical calculations of the CpMoE(6)MoCp (E = P, As, Sb) triple-decker sandwich complexes showed that E(6) fragments in the central decks of the complexes are planar. Analysis of molecular orbitals involved in vibrational coupling demonstrated that filling the unoccupied molecular orbitals involved in vibronic coupling with electron pairs of Mo atoms suppresses the PJT effect in the CpMoE(6)MoCp (E = P, As, Sb) sandwich, with the E(6) ring becoming planar (D(6h)) upon complex formation. The AdNDP analysis revealed that bonding between C(5)H(5)(-) units and Mo atoms has a significant ionic contribution, while bonding between Mo atoms and E(6) fragment becomes appreciably covalent through the δ-type M → L back-donation mechanism.
三重夹心配合物 CpMoE(6)MoCp（E=P、As、Sb）的量子化学计算表明，配合物中心层的 E(6)片段是平面的。对参与振动耦合的分子轨道的分析表明，用 Mo 原子的电子对填充参与振子耦合的空分子轨道会抑制 CpMoE(6)MoCp（E=P、As、Sb）夹心化合物中的 PJT 效应，使 E(6)环在形成配合物时变为平面（D(6h)）。AdNDP 分析表明，C(5)H(5)(-)单元与 Mo 原子之间的键合具有显著的离子贡献，而 Mo 原子与 E(6)片段之间的键合通过 δ 型 M→L 反馈机制变得相当共价。
