Reactions of benzonitrile with diiodides of neodymium, dysprosium, and thulium

The reactions of LnI(2)(Ln = Nd, Dy, Tm) with benzonitrile are accompanied by disproportionation, resulting in the formation of triiodides LnI(3)(PhCN)(4) and an intractable mixture of monoiodine derivatives LnI(R)R'. Hydrolysis of the mixture gives 2,4,6-triphenyl-1,3,5-tiazine, 2,3,5,6-thetraphenyl-1,4-pyrazine, and 2,4,5-triphenylimidazole. The reaction of dysprosium diiodide with acrylonitrile gives a metal-containing polymer with a molecular weight of 2700. Treatment of the polymer with water results in separation of DyI2(OH)(H2O)(x) to give metal-free polyacrylonitrile with a molecular weight of 2400.