Structural and magnetic conformation of a cerocene [Ce(COT′′)₂]⁻ exhibiting a uniconfigurational f¹ ground state and slow-magnetic relaxation

Abstract

Magnet-like behaviour, in the form of slow relaxation of the magnetization, was observed for a monometallic cerium(III) sandwich complex. The use of trimethylsilyl substituted COT ligands (COT'') led to the formation of a staggered COT'' arrangement in the cerocene-type sandwich complex with a well-defined oxidation state of +3 for the Ce ion.

Lanthanides and actinides: Annual survey of their organometallic chemistry covering the year 2014

“…The molecular structures of Tm 2 @C s (6)-C 82 and Tm 2 C 2 @C s (6)-C 82 have been determined by means of single-crystal X-ray diffraction using co-crystals with nickel octaethylporphyrin (Ni(OEP)). It was found that the relative metal positions of Tm@C s (6)-C 82 , Tm 2 @(I)-C82 and Tm 2 C 2 @(I)-C 82 are similar, and the Tm positions are slightly shifted off-center by the encapsulation of additional Tm and C atoms. The molecular orientations of Tm@C s (6)-C 82 , Tm 2 @(I)-C82 and Tm 2 C 2 @(I)-C 82 relative to Ni(OEP) were also found to be similar with each other.…”

“…It was found that the relative metal positions of Tm@C s (6)-C 82 , Tm 2 @(I)-C82 and Tm 2 C 2 @(I)-C 82 are similar, and the Tm positions are slightly shifted off-center by the encapsulation of additional Tm and C atoms. The molecular orientations of Tm@C s (6)-C 82 , Tm 2 @(I)-C82 and Tm 2 C 2 @(I)-C 82 relative to Ni(OEP) were also found to be similar with each other. These facts demonstrated that the stable endohedral Tm positions are not fundamentally affected by the addition of the other Tm atoms but dependent on the kind of the fullerene cage structure.…”

“…It was found that despite having analogous structures, the YCN@C82 and TbCN@C 82 series exhibit dissimilar thermodynamic stabilities, which lead to different components of experimental products. Significant relationships between the thermodynamic stabilities and geometry structures of C 82 metallofullerenes were disclosed.…”

“…All nine IPR C 82 isomers and two non-IPR C 82 isomers (C 2v (39705) and Cs(39663)) were considered to explore which one has the higher possibility of encapsulating a Sc 3 NC cluster in the C 82 fullerene (IPR = isolated pentagon rule). Significantly, the favorable binding energies and large HOMO-LUMO energy gaps suggested that the two non-IPR Sc 3 NC@C 2v (39705)-C82 and Sc 3 NC@Cs(39663)-C 82 isomers (cf.Figure 13) should be found among the possible structures of Sc 3 NC@C 82 . Furthermore, Raman spectra and 13 C NMR spectra were also explored to assist future experimental characterization [90].…”

“…Significant relationships between the thermodynamic stabilities and geometry structures of C 82 metallofullerenes were disclosed. Studies of the electronic configurations of MCN@C82 species not only explained their redox potentials but also discovered complicated interaction mechanisms within them. In addition, predictions of the optical spectra of observed MCN@C 82 species coincided well with experimental detections.…”