Novel Amido-Bridged Dinuclear Iridium(III) and Iridium(II) Complexes. Synthesis and Characterization of [Cp*Ir(μ2-NHC6H4R-p)3IrCp*]Cl (Cp* = η5-C5Me5; R = Me, H, Cl, CF3), [Cp*Ir{(μ2-NH)2C10H6-1,8}(μ2-X)IrCp*]X (X = Cl, Br), Cp*Ir{(μ2-NH)2C10H6-1,8}IrCp*, and [Cp*Ir{(μ2-NH)2C10H6-1,8}(μ2-H)IrCp*]O2C