PUB - Publikationen an der Universität Bielefeld

The compounds Me3Al-Me2NCH2NMe2-AlMe3 (1) and Me3Ga-Me2NCH2NMe2-GaMe3 (2) were prepared by reacting Me2NCH2NMe2 (TMMDA) with two equivalents of the metal trialkyls in hydrocarbon solutions. With the ether adduct Me3Ga.OEt2Me2NCH2NMe2 reacts to give the mono-adduct Me2NCH2NMe2-GaMe3 (3). These compounds were characterized by NMR spectroscopy (H-1, C-13 and Al-27) and by elemental analyses. Crystal structure investigations show 1 and 2 to be monomeric and to a adopt a trans, trans-conformation for their M-N-C-N-M backbones. 3 is also monomeric in the solid state, but adopts a cis, trans-conformation. Tetramethylformamidinium chloride and also chlorotetramethylformamidinium chloride reacts with lithium aluminium hydride to give the mono-adduct [Me2NCH2NMe2-AIH(3)](2) (4), which is dimeric and can be regarded as a double TMMDA adduct to Al2H6 with five-coordinate Al atoms. Ab initio calculations on the MP2/6311G** level of theory have been performed for the model compound H3N-H2Al(mu-H)(2)AlH2-NH3 to obtain its molecular structure and vibrational spectrum for comparison with 4 and for the assignment of its vibrational spectrum.