Ligand Lone-Pair Influence on Hydrocarbon C-H Activation: A Computational Perspective

Mid to late transition metal complexes that break hydrocarbon C-H bonds by transferring the hydrogen to a heteroatom ligand while forming a metal-alkyl bond offer a promising strategy for C-H activation. Here we report a density functional (B3LYP, M06, and X3LYP) analysis of cis-(acac)_2MX and TpM(L)X (M=Ir, Ru, Os, and Rh; acac=acetylacetonate, Tp=tris(pyrazolyl)-borate; X=CH_3, OH, OMe, NH_2, and NMe_2) systems for methane C-H bond activation reaction kinetics and thermodynamics.We address the importance of whether a ligand lone pair provides an intrinsic kinetic advantage through possible electronic d_π-p_π repulsions for M-OR and M-NR_2 systems versus M-CH_3 systems. This involves understanding the energetic impact of the X ligand group on ligand loss, C-H bond coordination, and C-H bond cleavage steps as well as understanding how the nucleophilicity of the ligand X group, the electrophilicity of the transition metal center, and cis-ligand stabilization effect influence each of these steps.We also explore how spectator ligands and second- versus third-row transition metal centers impact the energetics of each of these C-H activation steps

Angular Forces Around Transition Metals in Biomolecules

Quantum-mechanical analysis based on an exact sum rule is used to extract an semiclassical angle-dependent energy function for transition metal ions in biomolecules. The angular dependence is simple but different from existing classical potentials. Comparison of predicted energies with a computer-generated database shows that the semiclassical energy function is remarkably accurate, and that its angular dependence is optimal.Comment: Tex file plus 4 postscript figure

Carbon-Hydrogen Bond Activation by Titanium Imido Complexes. Computational Evidence for the Role of Alkane Adducts in Selective C-H Activation

This article reports calculations that probe the role of R (hydrocarbon) and R' (ligand substituent) effects on the reaction coordinate for C-H activation

Carbon-Oxygen Bond Formation via Organometallic Baeyer-Villiger Transformations: A Computational Study on the Impact of Metal Identity

Article discussing a computational study on the impact of metal identity and carbon-oxygen bond formation via organometallic Baeyer-Villiger transformations

Inter- and Intramolecular Experimental and Calculated Equilibrium Isotope Effects for (silox)₂(ᵗBu₃SiND)TiR + RH (silox = ᵗBu₃SiO): Inferred Kinetic Isotope Effects for RH/D Addition to Transient (silox)₂Ti=NSiᵗBu₃

This article discusses inter- and intramolecular experimental and calculated equilibrium isotope effects

Performance of Density Functional Theory for 3d Transition Metal-Containing Complexes: Utilization of the Correlation Consistent Basis Sets

Article discussing the performance of density functional theory for 3d transition metal-containing complexes and the utilization of the correlation consistent basis sets