Synthesis and Reactivity of Low-Valent f-Element Iodide Complexes with Neutral Iminophosphorane Ligands

Abstract

The coordination and reactivity of simple iodide salts of low-valent f elements [YbI, SmI, TmI, and UI(THF), where THF = tetrahydrofuran] with iminophosphorane (RP═NR') ligands are reported. The studied chelates were observed to adapt their geometry and effectively bind divalent ytterbium and samarium centers, as well as the trivalent uranium cation. The reactivity of the ytterbium adducts with benzophenone was found to be dependent on the steric demand of the supporting iminophosphorane ligand. In particular, a rare example of a stable charge-separated ketyl radical species is reported with ytterbium. Additionally, divalent thulium was observed to induce a reductive coupling at the ligand's central pyridine ring.

Quantification of the Interaction of SmI2 with Substrates and Ligands

“…Although some NMR spectra of organic compounds coordinated to samarium were published, their main purpose was the structural identification of these complexes, along with their crystal structure and other physical data. Furthermore,w ith the exception of one recent paper [6] (which relates to Sm 2 + ), the rest of the published NMR spectroscopic data relatest oS m 3 + complexes. [7] Here, we demonstrate how equilibrium constantsb etween SmI 2 and some classical ligands and substrates can be quantitatively determined and provide mechanistic insights for these interactions.…”

Atom economical coupling of benzophenone and N-heterocyclic aromatics with SmI2

“…[20][21][22][23][24][25] In particular, Kagan reported the reaction of ketones for the preparation of alcohols or pinacols, depending upon the reaction conditions. 26 After some of us demonstrated that this typical radical coupling induced by divalent lanthanides was reversible in multiple cases, [27][28][29][30] we were interested in investigating the Kagan reaction with benzophenone and SmI 2 in THF. The reaction with 1 eq.…”

Redox activity of a dissymmetric ligand bridging divalent ytter-bium and reactive nickel fragments

“…This occurred in multiple occasions after electron transfer from divalent lanthanides. 13,14,44 Compared to the relatively stable nature of the Cp* 2 Yb( phen), 2, 3 and 5 are rather thermosensitive. The eventual dimer-monomer equilibrium was not efficiently observed when dissolving the crystals of 2, 3 and 5 in THF-d 8 at room temperature.…”