Bis(trimethylsilyl)mercury (CH)Si-Hg-Si(CH) reacts with chloro-iminium and chloro-amidinium salts to give a metal-free carbene and elemental mercury. For example:
:(CH)Si−Hg−Si(CH) + RN=C(Cl)−Cl → RN−C−NR + Hg + 2(CH)SiCl