Ionic-Radius-Driven Selection of the Main-Group-Metal Cage for Intermetalloid Clusters [Ln@PbxBi14−x]q− and [Ln@PbyBi13−y]q− (x/q=7/4, 6/3; y/q=4/4, 3/3)

• Published in: Chemistry : a European journal Vol. 21; no. 1; pp. 386 - 394
• Main Authors: Ababei, Rodica, Massa, Werner, Weinert, Bastian, Pollak, Patrik, Xie, Xiulan, Clérac , Rodolphe, Weigend, Florian, Dehnen, Stefanie
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 02.01.2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc; Wiley-VCH Verlag
• Subjects: bismuth; Chemical Sciences; Chemistry; cluster compounds; Crystals; density functional calculations; lanthanides; lead; Material chemistry; X-rays; density functional calculations; cluster compounds; lead; bismuth; lanthanides
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201404904

Reactions of the binary, pseudo‐homoatomic Zintl anion (Pb2Bi2)2− with Ln(C5Me4H)3 (Ln=La, Ce, Nd, Gd, Sm, Tb) in the presence of [2.2.2]crypt in ethane‐1,2‐diamine/toluene yielded ten [K([2.2.2]crypt)]+ salts of lanthanide‐doped semimetal clusters with 13 or 14 surface atoms. Single‐crystal X‐ray diffraction and energy‐dispersive X‐ray spectroscopy indicated the presence of the anions [Ln@Pb6Bi8]3−, [Ln@Pb3Bi10]3−, [Ln@Pb7Bi7]4−, or [Ln@Pb4Bi9]4− in single or double salts; the latter showed various ratios of the components in the solid state. The anions are the first ternary intermetalloid clusters comprising only elements of the sixth period of the periodic table, namely, Pb, Bi and lanthanides. This study, which was complemented by ESI mass spectrometry and 139La NMR spectroscopy in solution, rationalizes a continuous development of the ratio of 13:14‐atom cages with the ionic radius of the embedded Ln3+ ion, which seems to select the most suitable cage type. Quantum chemical investigations helped to analyze this situation in more detail and to explain the observed subtle influence of the atomic radii. Magnetic measurements confirmed that the embedded Ln3+ ions keep their expected paramagnetic or diamagnetic nature. Exclusively period 6 elements constitute the ternary intermetalloid clusters obtained by reactions of (Pb2Bi2)2− with Ln(C5H5Me)3 (Ln=La, Ce, Nd, Gd, Sm, Tb) in ethane‐1,2‐diamine/[2.2.2]crypt/toluene, as ten [K([2.2.2]crypt)]+ salts of Ln3+‐doped semimetal clusters [Ln@Pb6Bi8]3−, [Ln@Pb3Bi10]3−, [Ln@Pb7Bi7]4−, and/or [Ln@Pb4Bi9]4−. X‐ray diffraction, ESI‐MS, 139La NMR spectroscopy, and DFT calculations rationalized a continuous development of the ratio of 13:14‐atom main‐group‐metal cages (see figure) with the ionic radius of the embedded Ln3+ ion.