Expanding the +2 Oxidation State of the Rare-Earth Metals, Uranium, and Thorium in Molecular Complexes

Electrochemical studies of tris(cyclopentadienyl)thorium and uranium complexes in the +2, +3, and +4 oxidation states

“…9 Inman and Cloke studied Th(IV)/ Th(III) redox couples and found that [ n Bu 4 N][BPh 4 ] was a good supporting electrolyte for their complexes. 15,17 Encouraged by their results, we utilized this supporting electrolyte to obtain electrochemical data in this study and on Cp 3 0 Th IV Cl: 18 Due to the importance of the tris(cyclopentadienyl) ligand set in the development of low oxidation state actinide chemistry, 19,20 the electrochemistry of a variety of tris(cyclopentadienyl)uranium and thorium complexes using Cp 00 , Cp 0 , and Cp tet ligands (Cp tet ¼ C 5 Me 4 H), Scheme 1, is reported here as well as the rst reported electrochemical measurements on isolated Th(II) complexes. 2 Also reported are spectroelectrochemical studies on the Th(II) compounds that led to the discovery of new synthetic routes to Th(II) compounds.…”

Lanthanidocenes: Synthesis, Structure, and Bonding of Linear Sandwich Complexes of Lanthanides

“…Our strategy is based on the use of divalent lanthanides, whose chemistry expended largely in the last decades, [34][35] with the next Hückel-aromatic and monoanionic ligand after the Cp ligand, the cyclononatetraenyl anion (Cnt, C 9 H 9 -, Chart 39 In this article, we report the original synthesis, the structure and the bonding of several Ln(Cnt) 2 complexes, a series of neutral and linear sandwich compounds of lanthanides, justifying the name of lanthanidocenes.…”

Property-Optimized Gaussian Basis Sets for Lanthanides

“…As the example of LnCp − 3 complexes (Ln = Ce-Nd, Sm) shows, 5d occupation is far from rare in low-valent lanthanide compounds. The response of the occupied d z 2 orbitals gives rise to novel optical [38][39][40]66,81 and magnetic 65,67,97,98 properties. Diffuse augmentation on lanthanide atoms is essential for accurate modeling of these properties.…”

“…The chemistry of lanthanide complexes in the +2 oxidation state, which was previously limited to Eu, Yb, and Sm, has been increasingly extended to other lanthanides. 40,[78][79][80] One of the most complete series of low-valent lanthanide complexes is LnCp − 3 (Cp = C 5 H 4 SiMe 3 ), which have been characterized for all lanthanides (except for radioactive Pm). [38][39][40]81 DFT studies showed that in the non-traditional LnCp − 3 complexes (Ln = Ce-Nd, Gd-Er) the highest occupied molecular orbitals (HOMOs) have d z 2 character, while the traditional complexes (in the sense of being part of better-known +2 chemistry, Ln = Sm-Eu, Tm-Yb) contain lanthanide +2 ions in their 4f n+1 configurations.…”

“…40,[78][79][80] One of the most complete series of low-valent lanthanide complexes is LnCp − 3 (Cp = C 5 H 4 SiMe 3 ), which have been characterized for all lanthanides (except for radioactive Pm). [38][39][40]81 DFT studies showed that in the non-traditional LnCp − 3 complexes (Ln = Ce-Nd, Gd-Er) the highest occupied molecular orbitals (HOMOs) have d z 2 character, while the traditional complexes (in the sense of being part of better-known +2 chemistry, Ln = Sm-Eu, Tm-Yb) contain lanthanide +2 ions in their 4f n+1 configurations. The 4f n+1 and 4f n 5d 1 configurations are close in energy in the Ln = Nd and Dy complexes, however these complexes were assigned 4f n 5d 1 configurations on the basis of their x-ray crystal structures and electronic absorption spectra.…”