Al-27 and C-13 NMR relaxation data are reported for the aminoalane series [R(2)AlNMe(2)](2), and Al-27 relaxation data, for the series [Me(2)AlR’](2) and Me(3)Al . R’H. A linear correlation exists between the Al-27 NMR half-height line width and molar volume for [Me(2)AlR’](2) and Me(3)Al . R’H, where R’H represents 12 secondary amines. Variable temperature Al-27 and C-13 NMR relaxation data suggest a single effective correlation time in the [R(2)AlNMe(2)](2) series.