title: Reactions of a gallium(II)-diazabutadiene dimer, [{{[(H)C(Bu(t))N]2}GaI}2], with [ME(SiMe3)2] (M = Li or Na; E = N, P, or As): structural, EPR, and ENDOR characterization of paramagnetic gallium(III) pnictide complexes.
abstract: The reactions of the paramagnetic gallium(II) complex [{(Bu(t)-DAB)GaI}2] (Bu(t)-DAB = {(Bu(t))NC(H)}2) with the alkali metal pnictides [ME(SiMe3)2] (M = Li or Na; E = N, P, or As) have been carried out under a range of stoichiometries. The 1:2 reactions have led to a series of paramagnetic gallium(III)-pnictide complexes, [(Bu(t)-DAB)Ga{E(SiMe3)2}I] (E = N, P, or As), while two of the 1:4 reactions afforded [(Bu(t)-DAB)Ga{E(SiMe3)2}2] (E = P or As). In contrast, treatment of [{(Bu(t)-DAB)GaI}2] with 4 equiv of [NaN(SiMe3)2] resulted in a novel gallium heterocycle coupling reaction and the formation of the diradical species [(Bu(t)-DAB)Ga{N(SiMe3)2}{[CC(H)N2(Bu(t))2]Ga[N(SiMe3)2]CH3}]. The mechanism of this unusual reaction has been explored, and evidence suggests it involves an intramolecular transmethylation reaction. The X-ray crystal structures of all prepared complexes are reported, and all have been characterized by EPR and ENDOR spectroscopies. The observed spin Hamiltonian parameters provide a detailed picture of the distribution of the unpaired spin density over the molecular frameworks of the complexes.
authors.affiliation: Center for Fundamental and Applied Main Group Chemistry, School of Chemistry, Cardiff University, P.O. Box 912, Park Place, Cardiff CF10 3TB, United Kingdom.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Antcliff
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Baker
authors.forename: Cameron
authors.initials: C
authors.lastname: Jones
authors.forename: Damien M
authors.initials: DM
authors.lastname: Murphy
authors.forename: Richard P
authors.initials: RP
authors.lastname: Rose