A rare gold(l) ethylene complex and the closely related copper(l) ethylene adduct have been isolated using [N{(C3F7)C(2,6-Cl2C6H3)N}(2)](-) as the supporting ligand. [N{(C3F7)C(2,6-Cl2C6H3)N}(2)]Au(C2H4) (1) is an air-stable solid. It features a U-shaped triazapentadienyl ligand backbone and a three-coordinate, trigonalplanar gold center. The copper(l) adduct [N{(C3F7)C(2,6-Cl2C6H3)N}(2)]Cu(C2H4) (2) also has a similar structure. The C-13 NMR signal. corresponding to the ethylene carbons of 1 appears at about 64 ppm upfield from the free ethylene, while the ethylene carbons of 2 show a relatively smaller (39 ppm) upfield shift. [N{(C3F7)C(2,6-Cl2C6H3)N}(2)]M(C2H4) (M = Cu, Au) mediate carbene-transfer reactions from ethyl diazoacetate to saturated and unsaturated hydrocarbons.