Capturing In+ monomers in a neutral weakly coordinating environment.

The application of a new bis(imino)pyridine ligand allowed the isolation and characterization of [{2,4-(t)Bu(2)C(6)H(3)N=CPh}(2)(NC(5)H(3))]In(+)(OTf)(-) as the first low-valent, main-group metal complex of this ligand scaffold. Structural analysis revealed a unique monomeric In(I) species with a surprisingly long metal-ligand bond. In conjunction with a density functional theory investigation, this complex is shown to display only nominal donor-acceptor interactions between the metal and the neutral ligand. The mixing of the occupied 5s metal orbital with the occupied ligand orbitals reduces the reactivity of the central atom and thus stabilizes this species. An In(III) species, [{2,4-(t)Bu(2)C(6)H(3)N=CPh}(2)(NC(5)H(3))]InCl(2)(+)InCl(4)(-) was also isolated and structurally characterized utilizing this ligand frame.