5-Norbornene anhydride-mercury compound (III) was synthesized. Since its infrared spectrum showed the shift of carbonyl absorption to a very low wave number side, O-Hg linkage was considered to be in an ionic form (III'), with the carbon in the bonded to mercury becoming a carbonium ion, suggesting the likelihood of its reaction with nucleophilic reagents. Reactions of III with nucleophilic reagents showed that III is reactive to H2S, KI, and KCN.
