Photoreactivity of mercarbides C(HgX)4 with X = chloride and acetate

The mercarbides C(HgX)4 with X− = Cl− and acetate− which are characterized by a tetrahedral (C4 −Hg2 +4)4 + core fragment show two absorptions in the UV spectral region at λmax = 234 nm and 270 nm. They are attributed to (C4 − → Hg2 +) LMCT transitions. LMCT excitation of C(HgX)4 in solution leads to a photoredox decomposition according to: C(HgX)4 + 2 H2O → CO2 + 4 Hg0 + 4 HX.