| Abstract: | CsEr10(C2)2]I18 and Er10(C2)2]Br18: Two New Examples for Reduced Halides of the Lanthanides with Isolated M10(C2)2] Clusters CsEr10(C2)2]I18 is obtained from the reaction of ErI3 with caesium and carbon in sealed tantalum containers at 700°C and Er10(C2)2]Br18 through the metallothermic reduction of ErBr3 with rubidium in the presence of carbon at 750°C in sealed niobium containers. The crystal structures {CsEr10(C2)2]I18: triclinic, P1 ; a = 1 105.2(8) pm, b = 1 112.0(7) pm; c = 1 122.9(8) pm; α = 66.91(3)°, β = 87.14(3)°; γ = 60.80(3)°; Z = 1; R = 0.049, Rw = 0.043; Er10(C2)2]Br18: monoclinic, P21/n, a = 971.8(6) pm, b = 1 623.4(9) pm, c = 1 163.8(6) pm, β = 104.00(6)°; Z = 2; R = 0.077, Rw = 0.057} contain isolated dimeric Er10(C2)2] clusters. Due to the inclusion of C2 units, the octahedra are elongated in the direction of the pseudo C4 axis. The connecting edges of the two octahedra are exceptionally short (316.7 pm and 314.8 pm respectively). The dimeric units are connected via Xi?a and Xa?i (X = Br, I) bridges according to Er10(C2)2X X ]X . Cs+ is surrounded by a cuboctahedron of iodide ions in CsEr10(C2)2]I18. |
