Molecular structure and intramolecular rearrangements in tris-2,2,6,6-tetramethyl-heptane-3,5-dione complexes, M(thd) 3 (M = B, Al, Ga, In, Tl) by DFT calculations

• Published in: Computational and theoretical chemistry 2011-07, Vol.967 (1), p.199-205
• Main Authors: Belova, N.V., Sliznev, V.V., Zhukova, T.A., Girichev, G.V.
• Format: Article
• Language: English
• Subjects: Chemical bonding; Density-functional theory; Geometrical structure; Intramolecular rearrangements; Metal beta-diketonates
• ISSN: 2210-271X
• DOI: 10.1016/j.comptc.2011.04.017

► Molecular structure. ► Quantum chemical calculation. ► Intramolecular rearrangements. ► Wiberg bond indexes. ► Net atomic charges. ► NBO analysis. The DFT calculations for tris-2,2,6,6-tetramethyl-heptane-3,5-dionato complexes of trivalent group 13 ions, M(thd) 3 (M = B, Al, Ga, In, Tl) were performed. The most likely geometrical structures of D 3 , D 3 h and C 2 v symmetry were examined. The D 3 molecular structure with distorted antiprismatic MO 6 coordination polyhedron corresponds to the minimum of potential energy hyper-surface (PES) for Al, Ga, In and Tl complexes. Calculated structures of MO 6 coordination polyhedron of studied complexes are in good agreement with the literature experimental results. The D 3 h and C 2 v configurations correspond to the first-order saddle points on the PES. The analysis of the different ways of intramolecular rearrangements was performed. Structure with D 3 symmetry was found to be a second-order saddle point on PES for B(thd) 3 complex. The configuration with one bidentate ligand and two monodentate bonded ligands and almost tetrahedron BO 4 is energetically most preferred for B(thd) 3.