| Abstract: | Two New Alkylimido-Methylgallanes with Cage Structure The tetrameric alkylimido-methylgallanes (MeGa? NR)4 (R = CH(CH3)2 ( iPr), C(CH3)3 ( tBu) and Me = CH3) have been prepared by pyrolyses of the dimeric amido compounds (Me2Ga? N(H)R)2 at 250–260°C. The mass, NMR and vibrational spectra are discussed, they prove almost identical structures of the skeletons. The X-Ray structure determination of (MeGa? NtBu)4 shows four heterocubane molecules in the trigonal unit cell (space group P3 c1, a = b = 1061.7(1), c = 3191.8(5) pm) and two disordered benzene solvate molecules. The Ga? N bonds range between 198.4 to 199.9 pm, the Ga? N? Ga and N? Ga? N bond angles lie between 90.6 to 91.4 and 88.6 to 89.2°, respectively. The structure was refined to an R1(R2)-value of 0.049 (0.057). |
