The reactions of (Me3Al)2 with 11 aminoarsines, Me2AsR (R = Et2N, Prn2N, Pri2N, Bun2N, Bui2N, C4H8N, C5H10N, C6H12N, CH3NC4H8N, Ph2N and Bzl2N, where Bzl = PhCH2), have been studied by multinuclear NMR spectroscopy. The results are compared with those of our previous studies on the Me3Al/Me2AsNMe2 system. In each case, except Me2AsNPh2, the final reaction products are [Me2AlR]2 and Me3As. The reaction intermediates have been identified and, in most cases, the AsNAl adducts and Me2AlR·AlMe3 are observed. With Me2AsNPh2 the product is Me3As·Me2AlNPh2. The influence of steric and electronic effects on arsenic vs nitrogen bonding site preference, adduct stability, complexity of overall reaction and ease of forming Me3As and [Me2AlR]2 are discussed. [Me2AlR]2, Me2AlR·AlMe3 and Me3Al·HR have been independently synthesized and characterized. A comparison of the 13C NMR chemical shift values for Me2AsR and Me2AsR·AlMe3 provides information on steric interactions that influence adduct stability. © 1993.