Specific chemical behavior of NdII and DyII iodides in reactions with aromatic compounds

Benzene, toluene, tert-butylbenzene, or biphenyl virtually do not react with NdI2 (1) or DyI2 (2) in THF at -20degreesC but appreciably accelerate the reactions of these salts with solvents, resulting in LnI(3) and intractable mixtures of products of the general composition [LnI(H)(R)(THF)] (R are fragments of the THF molecule). The same effect is induced by the addition of diphenylmercury or tetraphenyltin to solutions of 1 or 2. Phenol easily oxidizes 1 and 2 to give at 0 degreesC the PhOLnI(2)(THF)(x) complexes (x = 3, 4) in 55-95% yields. At -90 degreesC, iodide 2 is converted into a similar complex PhODyI2(THF)(4), whereas 1 gives a mixture of PhONdI2(THF)(4), (PhO)(2)NdI(THF)(5), NdI3(THF)(3), and [NdI(H)R(THF)]. A plausible pathway of the reactions including the intermediate formation of extremely reactive monovalent lanthanide iodides LnI is discussed.