Theoretical and Structural Analysis of the Unsymmetrical Bridging Coordination Mode of the Nonconical PNR2 Ligands in Ru4(CO)12(μ4-PNR2)2 Clusters
journal contributionposted on 16.05.2000, 00:00 by Samia Kahlal, Konstantin A. Udachin, Ludmila Scoles, Arthur J. Carty, Jean-Yves Saillard
The X-ray molecular structure of Ru4(CO)12(μ4-PNEt2)2 exhibits a strong distortion of its octahedral Ru4P2 core toward D2d symmetry, with a puckered Ru4 “square” and a phosphorus coordination mode intermediate between μ4 and μ2. The electronic origin of this distortion is analyzed with the help of EHT and DFT calculations. This structural peculiarity originates from the nonconical nature of the PNR2 ligand and from the ability of the Ru4(CO)12 unit to adapt its conformation and bonding ability to this unsymmetrical bonding.