Synthesis and Properties of Group 13 Element Compounds (Al, Ga, In) with the Polydentate 1-[2-(Dimethylamino)ethyl]-2,3,4,5-tetramethylcyclopentadienyl Ligand. X-ray Crystal Structures of (C5Me4CH2CH2NMe2)MX2 (MX2 = AlMe2, AlCl2, InCl2)1

Several new group 13 element compounds containing the 1-[2-(dimethylamino)ethyl]-2,3,4,5-tetramethylcyclopentadienyl ligand (Cp∧) are described. Reaction of the respective element halide with Cp ∧ Li leads to the compounds 2 − 8 of the type (C 5 Me 4 CH 2 CH 2 NMe 2 )MX 2 [ 2, M = Al, X = CH 3; 3, M = Al, X = C 2 H 5; 4, M = Al, X = Cl; 5, M = Al, X = Br; 6, M = Al, X = I; 7, M = Ga, X = Cl; 8, M = In, X = Cl]. All compounds feature monomeric structures with intramolecularly coordinated dimethylamino groups. The dynamic behavior in solution is based on fast haptotropic shifts in a “windscreen-wiper” type process. In the reaction of 5 with H 3 Al·NMe 3, the compound (C 5 Me 4 CH 2 CH 2 NMe 2 )Al(H)Br ( 9 ) is formed. The known correlation of the 27 Al NMR shift with the coordination number at aluminum can be extended to cyclopentadienyl compounds. The structures of 2, 4, and 8 were established by X-ray crystallography.