CsR(R6CoI12)2 (R = Gd, Er) and (CeI)0.26(Ce6MnI9)2:  Two New Structure Types Featuring R6Z Clusters

• Published in: Inorganic chemistry Vol. 45; no. 24; pp. 9696 - 9702
• Main Authors: Sweet, Lucas E, Hughbanks, Timothy
• Format: Journal Article
• Language: English
• Published: American Chemical Society 27.11.2006
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic060439d

Compounds adopting two new structure types containing discrete lanthanide clusters have been found, CsR(R6CoI12)2 (R = Gd or Er) and (CeI)0.26(Ce6MnI9)2. CsEr(Er6CoI12)2 and CsGd(Gd6CoI12)2 were synthesized in reactions of CsI, RI3, CoI2, and R metals (3:19:6:23) heated to 750 °C for 500 h followed by slow cooling (0.1 °C/min). The X-ray crystal structure of CsEr(Er6CoI12)2 was solved in the Pa3̄ space group with a = 18.063(2) Å at 250 K (Z = 4, R 1 [I > 2σ(I)] = 0.0459). (CeI)0.26(Ce6MnI9) was synthesized by combining KI, CeI3, MnI2, and Ce metal and heating to 850 °C for 500 h. The single-crystal X-ray structure for (CeI)0.26(Ce6MnI9)2 was solved in the trigonal, P3̄ (147) space group with lattice parameters of a = 11.695(1) Å and c = 10.8591(2) Å (Z = 2, R 1 [I > 2σ(I)] = 0.0895). Elemental analyses (X-ray photoelectron spectroscopy (XPS) and atomic absorption spectroscopy (AAS)) were performed and show the absence of potassium in the structure. A disorder model was refined for the atoms in the large cavity. The magnetic susceptibility data for CsGd(Gd6CoI12)2 is consistent with strong intracluster ferromagnetic coupling, but intercluster antiferromagnetic coupling suppresses the susceptibility below 70 K.