title: Computational study of C(sp3)-O bond formation at a PdIVcentre.
abstract: This report describes a computational study of C(sp3)-OR bond formation from PdIVcomplexes of general structure PdIV(CH2CMe2-o-C6H4-C,C')(F)(OR)(bpy-N,N') (bpy = 2,2'-bipyridine). Dissociation of-OR from the different octahedral PdIVstarting materials results in a common square-pyramidal PdIVcation. An SN2-type attack by-OR (-OR = phenoxide, acetate, difluoroacetate, and nitrate) then leads to C(sp3)-OR bond formation. In contrast, when-OR = triflate, concerted C(sp3)-C(sp2) bond-forming reductive elimination takes place, and the calculations indicate this outcome is the result of thermodynamic rather than kinetic control. The energy requirements for the dissociation and SN2 steps with different-OR follow opposing trends. The SN2 transition states exhibit "PdCO" angles in a tight range of 151.5 to 153.0°, resulting from steric interactions between the oxygen atom and the gem-dimethyl group of the ligand. Conformational effects for various OR ligands and isomerisation of the complexes were also examined as components of the solution dynamics in these systems. In all cases, the trends observed computationally agree with those observed experimentally.
authors.affiliation: School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia. allan.canty@utas.edu.au.
authors.forename: Allan J
authors.identifier: http://orcid.org/0000-0003-4091-6040
authors.initials: AJ
authors.lastname: Canty
authors.affiliation: School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia. allan.canty@utas.edu.au.
authors.forename: Alireza
authors.identifier: http://orcid.org/0000-0003-2383-6380
authors.initials: A
authors.lastname: Ariafard
authors.affiliation: Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109, USA. mssanfor@umich.edu.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Camasso
authors.affiliation: Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109, USA. mssanfor@umich.edu.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Higgs
authors.affiliation: School of Physical Sciences, University of Tasmania, Private Bag 75, Hobart, Tasmania 7001, Australia. allan.canty@utas.edu.au.
authors.forename: Brian F
authors.initials: BF
authors.lastname: Yates
authors.affiliation: Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109, USA. mssanfor@umich.edu.
authors.forename: Melanie S
authors.initials: MS
authors.lastname: Sanford