This work was conducted as part of our continuing effort to determine the factors that affect cation formation for organometallic aluminum complexes. In this study, the interactions of R2AlX (where R = Me, Bu-i, Bu-t; X = Cl, Br, I) with the monodentate bases thf, pyridine, NEt3, (HNPr2)-Pr-i, (H2NBu)-Bu-i, (H2NBu)-Bu-t, and O=PPh3 are examined to determine the role of the base in cation formation. These reactions resulted in the neutral adducts of the general form R2AlX . base (1-6, 8, 10, and 12) as well as the cationic complexes [R2Al(base)(2)]X (7, 9, and 11). The reactions of Me2AlX (where X = Cl, Br) with PMDETA (N,N’,N ",N "’-pentamethyldiethylenetriamine) and the catalytic activity of the resulting cationic complexes (13 and 14) are also discussed. All of the compounds were characterized by mp, IR, H-1-NMR, and elemental analyses, and in one an X-ray crystallographic study was carried out, X-ray data for 13 : triclinic, , a = 6.9542(6) Angstrom, b = 12.2058(10) Angstrom, c = 13.2417(11) Angstrom, alpha = 106.236(2)degrees, beta = 98.885(2)degrees, gamma = 93.807(2)degrees, V = 1059.06(15) Angstrom(3), and Z = 2 for 181 parameters refined on 4358 reflection shaving F > 6.0 sigma(F), R = 0.0697, and R-w = 0.0697.