CONSEQUENCES OF THE FORMATION ORGANOMETALLIC EXCIPLEX [HG(ETA-2-ARENE)] IN MERCURY-PHOTOSENSITIZED REACTIONS OF ARENES - C-C, C-O, AND C-N BOND-CLEAVAGE

We have previously shown that mercury-photosensitized reactions give a n unexpected C-C bond cleavage for PhCH(2)-CH3 and related aromatic sy stems. In this paper we report further theoretical and experimental st udies that demonstrate the importance of organometallic intermediates of the type (3)[Hg(eta(2)-ArR)] in this chemistry and suggest how the C-C cleavage reaction occurs. We also find that in addition to these C -C bond cleavage reactions, analogous C-O and C-N bond cleavages can a lso occur with the following preference order for bond cleavage: C-O > C-N > C-C.