The X-ray crystal structures of a series of group 12 metal alkyl adducts Me2M[Me2N(CH2)2NMe2] {M = Zn (1), Cd (2)) and (Me3CCH2)2M[Me2N(CH2)2NMe2] {M = Zn (3), Cd (4)} have been determined. Each adduct exists as a mononuclear, molecular unit with pseudo-tetrahedral coordination at the metal centre. Compound 1 crystallizes in space group P2(1)/a, a = 13.868(3), b = 11.616(2) and c = 7.588(2) angstrom, beta = 94.83(2)-degrees, compound 2 in space group Cmca, a = 11.196(2), b = 12.179(2) and c = 17.969(3) angstrom. Compounds 3 and 4 are isostructural in space group C2/c with the following unit cell dimensions for Zn {Cd}: a = 17.167(5) (17.604(5)), b = 9.369(3) {9.484(3)}, and c = 12.916(3) (12.758(3)) angstrom, beta = 107.83(2) {106.07(2)}-degrees. Compound 1 and the parent alkyl of 4 have been used successfully in the growth of thin films by metalloorganic chemical vapour deposition, 1 as a dopant in the growth of p-type GaAs, and [Me3CCH2]2Cd as a Group 12 source in the growth of CdS.