Tetrakis(dimethylamino)ethylene (TDAE) is an
organic compound with the formula [C(NMe2)22 (where Me = CH3), classified as an
enamine. It is a colorless liquid. Primary and secondary enamines tend to isomerize, but tertiary enamines are kinetically stable.[1] The unusual feature of TDAE is that it is a tetra-enamine. The pi-donating tendency of the amine groups strongly modifies the properties of the molecule, which does exhibit properties of a typical
alkene.[2]
TDAE is an electron donor with E = 1.06 V vs Fc+/0.[5][6] It forms a charge transfer salt with
buckminsterfullerene:[7]
C2(N(CH3)2)4 + C60 → [C2(N(CH3)2)4+][C60−
Oxidation affords a dication.
Structure
Crystallographic analysis show that TDAE is a highly distorted alkene, the dihedral angle for the two N2C termini is 28″. The C=C distance is alkene-like, 135 pm. The nearly isostructural tetraisopropylethylene also has a C=C distance of 135 pm, but its C6 core is planar. In contrast, [TDAE]2+ is an alkane with multi-C-N bonds.
^David M. Lemal (1968). "Tetraaminoethylenes". In Saul Patai (ed.). The Amino Group. PATai's Chemistry of Functional Groups. pp. 701–748.
doi:
10.1002/9780470771082.
ISBN9780470771082.
^H.E. Winberg; J. R. Downing; D. D. Coffman (1965). "The Chemiluminescence of Tetrakis(dimethylamino)ethylene". J. Am. Chem. Soc. 87 (9): 2054–2055.
doi:
10.1021/ja01087a039.
^Bock, Hans; Borrmann, Horst; Havlas, Zdenek; et al. (1991). "Tetrakis(dimethylamino)ethene: An Extremely Electron-Rich Molecule with Unusual Structure both in the Crystal and in the Gas Phase". Angewandte Chemie International Edition in English. 30 (12): 1678–1681.
doi:
10.1002/anie.199116781.