Some observations on the minor products of the reaction of 2,2′-dilithiobiphenyl with mercuric chloride

Abstract

Reaction of 2,2′-dilithiobiphenyl (formed from 2,2′-diiodobiphenyl and lithium in diethyl ether) with mercuric chloride gives the ortho-biphenylenemercury trimer (I) with 2,2′-bis(iodomercury)biphenyl (II) as an isolatable intermediate. The mass spectrum of impure 2,2′-bis(iodomercury)biphenyl at high sensitivity shows ion clusters which are interpreted as the ions of a polyphenyl iodomercury complex [Hg 3(C 6H 4) 4I 2] (III) which is identified as a further intermediate in the production of ortho-biphenylenemercury trimer and several iodomercury cations of general formula [Hg xI y] +, where x, y = 1, 2, 3. A fragmentation scheme is presented to account for these unusual iodomercury cations. Reaction mechanisms are presented to account for the production of II and III.