Tetraaminoethylenes react with acids to give formamidinium salts.
Tetraaminoethylenes react with oxygen to given ureas (R2N)2C=O, with the bis-tetramethyl example (Me2N)2C=C(NMe2)2 emitting a green-blue light upon reaction, and was used by the downed US navy pilots to signal for help in World War II.