Synthesis and Characterization of Thorium(IV) and Uranium(IV) Corrole Complexes

Abstract

The first examples of actinide complexes incorporating corrole ligands are presented. Thorium(IV) and uranium(IV) macrocycles of Mes2(p-OMePh)corrole were synthesized via salt metathesis with the corresponding lithium corrole in remarkably high yields (93% and 83%, respectively). Characterization by single-crystal X-ray diffraction revealed both complexes to be dimeric, having two metal centers bridged via bis(μ-chlorido) linkages. In each case, the corrole ring showed a large distortion from planarity, with the Th(IV) and U(IV) ions residing unusually far (1.403 and 1.330 Å, respectively) from the N4 plane of the ligand. (1)H NMR spectroscopy of both the Th and U dimers revealed dynamic solution behavior. In the case of the diamagnetic thorium corrole, variable-temperature, DOSY (diffusion-ordered) and EXSY (exhange) (1)H NMR spectroscopy was employed and supported that this behavior was due to an intrinsic pseudorotational mode of the corrole ring about the M-M axis. Additionally, the electronic structure of the actinide corroles was assessed using UV-vis spectroscopy, cyclic voltammetry, and variable-temperature magnetic susceptibility. This novel class of macrocyclic complexes provides a rich platform in an underdeveloped area for the study of nonaqueous actinide bonding and reactivity.

Control of clustering behavior in anionic cerium(iii) corrole complexes: from oligomers to monomers

“…Melting points were determined using sealed capillaries prepared under nitrogen and are uncorrected. Tris(bis(trimethylsilyl)amino)cerium(III) (Ce(HMDS) 3 ; CeN 3 *), Tris(bis(trimethylsilyl)amino)lutetium(III) (Lu(HMDS) 3 ; LuN 3 *) 14 and 5,15-bis(2,4,6-trimethylphenyl)-10-(4-methoxyphenyl)-corrole (Mes 2 Ani-corrole) 13b were prepared according to previously reported procedures. Cyclopentadienylsodium, potassium tris(pyrazolyl)borate and 2.2.2-cryptand were obtained from Aldrich.…”

“…7b, 9–11 Considering the interest in tetrapyrroles and corroles being a member of this ligand family, it is remarkable that f -element corrole chemistry is still considerably underdeveloped. 12,13 …”

Oxidative Metalation as a Route to Size‐Mismatched Macrocyclic Complexes: Osmium Corroles

“…[4] Yet porphyrins and corroles share only a superficial similarity. These differences are particularly pronounced for 4d and 5d transition metals, [5] whose ionic radii are about 0.1-0.2 longer than those of their 3d congeners. These differences are particularly pronounced for 4d and 5d transition metals, [5] whose ionic radii are about 0.1-0.2 longer than those of their 3d congeners.…”

Carbon–Nitrogen Bond Cleavage by a Thorium‐NHC‐bpy Complex

“…[1][2][3] Ther ich reaction chemistry of thorium has been most developed in metallocene-supported systems,o utside of which relatively few alternative supporting ligand frameworks have been explored. Our interest in utilizing new ligand platforms [4][5][6] recently led to the discovery of auseful bis(NHC)borate motif that stabilizes reactive thorium compounds. [7] Upon also incorporating ar edox-active bipyridine ligand into the coordination sphere,t he NHC-thorium-bpy complex (1)w as found to engage in ar ange of chemical transformations and support an unusual open-shell singlet electronic structure (f 1 p* 1 ).…”