Rhodium(III) and Iridium(III) Complexes of a NHC-Based Macrocycle: Persistent Weak Agostic Interactions and Reactions with Dihydrogen.

ABSTRACT: The synthesis and characterization of five-coordinate rhodium(III) and iridium(III) 2,2'-biphenyl complexes [M(CNC-12)(biph)][BAr^F ₄] (M = Rh (1a), Ir (1b)), featuring the macrocyclic lutidine- and NHC-based pincer ligand CNC-12 are reported. In the solid state these complexes are notable for the adoption of weak ε-agostic interactions that are characterized by M···H-C contacts of ca. 3.0 Å by X-ray crystallography and ν(CH) bands of reduced wavenumber by ATR IR spectroscopy. Remarkably, these interactions persist on dissolution and were observed at room temperature using NMR spectroscopy (CD₂Cl₂) and solution-phase IR spectroscopy (CCl₄). The associated metrics point toward a stronger M···H-C interaction in

SUBMITTER: Gyton MR 

PROVIDER: S-EPMC6234485 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature