Crystal structures of extended europium cyanamide-carbodiimide compounds derived from different reaction conditions:: Temperature-controlled syntheses of In0.08Eu4(NCN)3I3, Eu8I9(CN)(NCN)3, and In0.28Eu12(NCN)5I14.91

A different thermal treatment of identical reactants (EuI2, NaCN, NaN3, and InI) leads to the formation of the three title compounds. In0.08Eu4(NCN)(3)I-3 is isotypic with the reported LiEu4(NCN)(3)I-3, Eu8I9-(CN)(NCN)(3) represents the first mixed cyanide-cyanamide rare-earth compound, and In0.28Eu12(NCN)(5)I-14.91 is characterized by a sandwichlike stacking motif involving Eu-4-NCN double layers stuffed by a layer of vertex-sharing InI6 octahedra. The redox behavior of In is the main factor that leads to alternative product formation as a function of the temperature.