Lanthanide corroles: a new class of macrocyclic lanthanide complexes

Abstract

The first examples of lanthanide corroles are prepared by two synthetic routes. (Mes2(p-OMePh)corrole)La·4.5DME (1·4.5DME) and (Mes2(p-OMePh)corrole)Tb·4DME (2·4DME) are prepared from the free base corrole and Ln((NSiMe3)2)3, while (Mes2(p-OMePh)corrole)Gd·TACNMe3 (3·TACNMe3) is prepared by metathesis of the recently reported Li3 corrole and GdCl3.

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

“…This is in contrast to the recently reported lanthanide corroles, as well as the actinide porphyrins, which are all monomeric. 23,24,34 The coordination geometry about the metal center is approximately dodecahedral, and both the metal−chloride 38,42−45 The average Th−N distance (2.39(1) Å) is longer than is typical for a Th−amido bond, but comparable to that of the thorium(IV) porphyrin (2.40 Å). 23 Likewise, the average U−N distance of 2.33(1) Å is slightly shorter than the analogous uranium(IV) porphyrin U− N distance at 2.41 Å.…”

“…The dynamic solution behavior seen in the aromatic region is similar to that observed for the analogous lanthanide corroles and is attributed to the highly facile exchange of coordinating solvent. 34 However, the splitting of the aliphatic peaks is unique to the dimeric actinide corroles and therefore could be due either to an equilibrium between the dimer observed in the solid state and a potential monomer in solution or to an intrinsic pseudorotational mode of the dimer complex itself (Scheme 2). Upon performing DOSY (diffusion-ordered) 1 H NMR spectroscopy, a single diffusion coefficient was observed (2.55 × 10 −6 cm 2 s −1 ), consistent with the presence of the dimeric species (r s = 9.9 Å) (see the Supporting Information, Figure S6).…”

Rare Earth Arene-Bridged Complexes Obtained by Reduction of Organometallic Precursors

“…Fryzuk and co-workers pioneered the use of multidentate amidophosphine ligands, which combine soft phosphine and hard amide donors, and incorporated such motifs into the coordination sphere of group 3 metals, including the tridentate [N(SiMe2CH2P i Pr2)2] -(P2N) in (P2N)ScR2 (R = Me, Et, CH2SiMe3) (Fryzuk et al, 1996), tetradentate (PhP[CH2(SiMe2)N(SiMe2)CH2]2PPh) 2-(P2N2) in (P2N2)Y[CH(SiMe3)2] (Fryzuk et al, 1997), and, recently, the tetradentate fc(NP i Pr2)2 in [(fc(NP i Pr2)2)Sc(THF)(-H)]2 (Halcovitch and Fryzuk, 2013). J. Arnold popularized porphyrins as supporting ligands for scandium organometallic complexes (Arnold and Hoffman, 1990;Arnold et al, 1993), and, recently, synthesized lanthanum and terbium corrole complexes (Buckley et al, 2013). Several groups reported on the use of mono-and bis-amidinate rare earth complexes as analogues of Cp*2M (Duchateau et al, 1993;Hagadorn and Arnold, 1996;Wedler et al, 1990).…”

Lanthanide–tetrapyrrole complexes: synthesis, redox chemistry, photophysical properties, and photonic applications

“…Corroles are contracted 18p electron macrocycles containing a direct carbon-carbon single bond between two pyrrole rings; since they have three NH groups in the inner core, they act as trianionic ligands. The first lanthanide complexes with corroles were reported in 2013 249 (n = 0-3). 251 For the first series (Ln = Pr-Tb, except Tm), halfwave potentials for five oxidation and three reduction steps were determined.…”