title: Pendant ancillary ligand switches off auto-oxidation of group 13 metal alkyl compounds bearing non-bulky alkyl groups.
abstract: The reaction of 3,5-di-2-pyridyl-1,2,4-triazole with excess Al(CH3)3 and Ga(CH3)3 afforded (3,5-di-2-pyridyl-1,2,4-triazolate)Al(CH3)2•3Al(CH3)3 (1) and (3,5-di-2-pyridyl-1,2,4-triazolate) Ga(CH3)2•3Ga(CH3)3 (2) respectively. 1 and 2 reacted with oxygen gas to produce (CH3)2M(µ-3,5-di-2-pyridyl-1,2,4-triazolate)(µ-OCH3)M(CH3)2 (M = Al, 3; M = Ga, 4). 3 and 4 contain the non-bulky dimethylalumino moiety, yet they are indefinitely stable in the presence of oxygen gas. This increased stability towards oxygen is due to ancillary 2-pyridyl groups bonding to the metal centers producing a pseudo-trigonal pyramidal Al and Ga environments. This environment blocks oxygen from further inserting into the M-C bond. The Al-N(pyridine) and Ga-N(pyridine) bonds reported herein are extremely elongated yet inactive towards dissociation due to the chelate effect.
authors.affiliation: Department of Chemistry, the Petroleum Institute, Abu Dhabi, United Arab Emirates.
authors.forename: Issam
authors.initials: I
authors.lastname: Kobrsi
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005708:Gallium / Q000737:chemistry*; D008024:Ligands; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D011725:Pyridines / Q000737:chemistry*; D014230:Triazoles / Q000737:chemistry*
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D011725:Pyridines; D014230:Triazoles; D005708:Gallium; D000535:Aluminum