Ortho-aryl substituted DPEphos ligands: rhodium complexes featuring C-H anagostic interactions and B-H agostic bonds.

ABSTRACT: The synthesis of new Schrock-Osborn Rh(i) pre-catalysts with ortho-substituted DPEphos ligands, [Rh(DPEphos-R)(NBD)][BAr^F ₄] [R = Me, OMe, ⁱPr; Ar^F = 3,5-(CF₃)₂C₆H₃], is described. Along with the previously reported R = H variant, variable temperature ¹H NMR spectroscopic and single-crystal X-ray diffraction studies show that these all have axial (C-H)⋯Rh anagostic interactions relative to the d⁸ pseudo square planar metal centres, that also result in corresponding downfield chemical shifts. Analysis by NBO, QTAIM and NCI methods shows these to be only very weak C-H⋯Rh bonding interactions, the magnitudes of which do not correlate with the observed chemical shifts. Instead,

SUBMITTER: Race JJ 

PROVIDER: S-EPMC8246285 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature