A crystallographically characterized salt of self-generated N-protonated tetraethylurea.

The reaction of 1,1,3,3-tetraethylurea (teu) with WCl6 in dichloromethane afforded [teuH][WCl6], 1, in 50-60% yield. The X-ray structure determined for includes the first example of crystallographic characterization of a N-protonated urea. According to spectroscopic and DFT outcomes, the formation of 1 is the result of an electron transfer/C-H activation process.