title: Bulky aryl functionalized carbazolyl ligands: amido alternatives to the 2,6-diarylphenyl ligand class?
abstract: Sterically encumbered amido ligands based on a 1,8-diarylcarbazol-9-yl backbone have been investigated as electronically distinct alternatives to the widely-used terphenyl ligand class in the stabilization of low-coordinate metal complexes, and structurally characterized for the first time. While 1,8-diphenylcarbazol-9-yl derivatives are readily available, facile rotation about the Cipso-Cipso bonds leads to structurally characterized main group derivatives {e.g., [(1,8-Ph,-3,6-Me2C12H4N)K]2} in which the coordination geometry at the metal centre is augmented by secondary metal arene interactions. By contrast, the extra bulk inherent in the corresponding 1,8-dimesityl ligand results in essentially perpendicular alignments of the arene and carbazole planes, and a substituent-enforced sterically protected pocket. Comparative structural studies of complexes containing the GaCl2 fragment imply that the 1,8-dimesitylcarbazol-9-yl framework offers greater steric protection at the metal centre than does the corresponding 2,6-dimesitylphenyl ligand.
authors.affiliation: Inorganic Chemistry, University of Oxford, South Parks Road, Oxford, UK.
authors.forename: Natalie D
authors.initials: ND
authors.lastname: Coombs
authors.forename: Andreas
authors.initials: A
authors.lastname: Stasch
authors.forename: Andrew
authors.initials: A
authors.lastname: Cowley
authors.forename: Amber L
authors.initials: AL
authors.lastname: Thompson
authors.forename: Simon
authors.initials: S
authors.lastname: Aldridge
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry; D002227:Carbazoles / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005708:Gallium / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D011188:Potassium / Q000737:chemistry
chemical_list: D001555:Benzene Derivatives; D002227:Carbazoles; D008024:Ligands; D009942:Organometallic Compounds; C010219:mesitylene; D005708:Gallium; D011188:Potassium