Amine involvement in the self-association of planar complexes of the type, cis-Ir(CO)2Cl(primary amine)

Publication date: Available online 11 January 2019Source: Journal of Organometallic ChemistryAuthor(s): Emily M. Gussenhoven, Marilyn M. Olmstead, Alan L. BalchAbstractExamination of crystals of cis-Ir(CO)2X(p-toluidine) (X = Cl,Br, I), by single crystal X-ray diffraction shows that the individual monomers self-associate to form extended columns with Ir⋯Ir separations ranging from 3.33 Å for the chloro complex to 3.68 Å in the iodo complex. The columnar structure is reinforced by hydrogen bonding between the halide ligand in one molecule with an N-H group in an adjacent molecule. This hydrogen bonding causes adjacent molecules to adopt nearly eclipsed orientations. In contrast, the positions of the methyl groups in cis-Ir(CO)2Cl(o-toluidine) and cis-Ir(CO)2Cl(2,6-dimethylaniline) limit intermolecular interactions to the formation of dimers connected by Ir⋯Ir interactions, and hydrogen bonding again occurs between the halide ligand in one molecule and the N-H group in an adjacent molecule. The UV/vis spectrum of cis-Ir(CO)2Cl(p-toluidine) provides evidence that the self-association also occurs in solution. The positive ion mass spectrum of laser ablated crystals of cis-Ir(CO)2Br(p-toluidine) reveals the presence of monomeric, dimeric, and trimeric cations.Graphical abstract

Source: Journal of Organometallic Chemistry - January 12, 2019 Category: Chemistry Source Type: research