Arene-ligated heteroleptic terphenolate complexes of thorium

Abstract

Bulky terphenolate ligands allow the synthesis of rare heteroleptic thorium chloride, and borohydride complexes; in the absence of donor solvents, the terphenolate ligands protect the metal ions through neutral Th-η(6)-arene interactions in a thorium bis(arene) sandwich motif.

Thorium(IV) and Uranium(IV) trans-Calix[2]benzene[2]pyrrolide Alkyl and Alkynyl Complexes: Synthesis, Reactivity, and Electronic Structure

“…Thorium arene interactions are rare, with only a few examples reported in the literature. 39,[59][60][61][62] This binding mode of (L) 2has previously been observed for U III and Np III complexes of the form [(L)AnX] (X = I, BH 4 , N(SiMe 3 ) 2 , O-2,6-t Bu 2 -C 6 H 3 for U III and X = Cl for Np III ) and [(L)Np2Cl4(THF)3] but not for complexes of An IV . 29,[63][64][65] Multinuclear NMR spectroscopic analysis suggests that 12 and 13 are analogues, however X-ray quality single crystals of 12 could not be obtained and the coordination mode of (L) 2in 12 could not be determined.…”

A Relativistic DFT Probe of Thorium and Protactinium Complexes Supported by Heterocalix[4]arene and Redox Properties of Early‐Middle Actinides

“…In contrast, the Th(III) complex remains rare due to the greatly negative reduction potential À2.35 V (vs. Fc + /Fc), [12][13] where 0.65 V was used to correct the original value (vs. NHE). [37] Although recent advance in the synthetic technique leads to more accessibility of Th III complexes, [18][19][20][21][22] the study of redox properties of Th VI /Th III complexes remains underexplored, [14][15][16][17] to our best of knowledge. For example, above E 0 of Th VI/III ions in water is the only available value, and moreover was obtained with the assistance of electron-transfer and f-d absorption bands.…”

“…The molecular chemistry of thorium is dominated by the IV oxidation state in contrast to III and II ones. Although extremely low reduction potentials of Th IV/III (‐3.0 V versus NHE) and Th III/II (‐4.9 V) were presumed, several Th III complexes and even one Th II complex have been synthesized and structurally characterized via massive efforts . In addition to commonly used cyclopentadienyl (Cp), cyclooctatetraenyl (COT) and their substituted derivatives, a small‐cavity macrocyclic trans ‐calix[2]pyrrole[2]benzene (H 2 L, Figure ), synthesized by the Sessler's group, has been found suitable for chelating Th IV .…”

“…Although extremely low reduction potentials of Th IV/III (-3.0 V versus NHE) and Th III/II (-4.9 V) were presumed, [12][13] several Th III complexes and even one Th II complex have been synthesized and structurally characterized via massive efforts. [14][15][16][17][18][19][20][21][22][23] In addition to commonly used cyclopentadienyl (Cp), cyclooctatetraenyl (COT) and their substituted derivatives, [14][15][16][17][18][19] a small-cavity macrocyclic transcalix [2]pyrrole [2]benzene (H 2 L, Figure 1), synthesized by the Sessler's group, [24] has been found suitable for chelating Th IV . [22][23] Interestingly, the flexibility of H 2 L allows its two binding pockets (BP), bis(arene) (marked as Ar L) and bis (pyrrolide) ( Pl L), to hold the actinide ion.…”

Borohydride-containing coordination polymers: synthesis, air stability and dehydrogenation

“…20 On the other hand, the extended BH 4 À -based crystal structures constructed from metal ions and organic bridging ligands are limited: ([Mg(BH 4 ) 2 (pyrazine) 2 ] and [Th(OTer Mes ) 2 (BH 4 ) 2 (4,4 0bipyridyl)]) were the only examples reported in the Cambridge Crystallographic Data Centre (CCDC) database. 21,22 As shown in previous studies, neutral N cations were incorporated to increase the solubility of the salt. Transition metal ion-based MBH precursors successfully form coordination bonds with pyridyl and imidazolate ligands, and 10 CP crystals were isolated as summarized in Fig.…”