Insertion of mercury into iron–halogen bonds. X-Ray structure of [(p-MeC6H4NC)5Fe → HgI2]
Abstract
The complexes [Fel2(CNR)4](R = Ph, p-MeC6H4 or But) react with Hg in the presence of CNR to give [(RNC)5Fe → HgI2], and exchange reactions with AgX (X = Br or Cl) lead to the corresponding halogeno-complexes [(RNC)5Fe → HgX2]. Treatment with 1 mol of AgClO4 affords the cationic complexes [(RNC)5Fe–HgX]ClO4 which are unstable towards mercury extrusion. The relative stability of the complexes is discussed in terms of the influence of the ligands co-ordinated to Hg and the steric and electronic characteristics of the RNC ligands. The structure of [(p-MeC6H4NC)5Fe → HgI2] has been determined: monoclinic, space group P21/a, a= 16.680(3), b= 18.031(4), c= 15.256(2)Å, β= 116.92(2)° and Z= 4.