Actinide arene-metalates: 2. A neutral uranium bis(anthracenide) sandwich complex and elucidation of its electronic structure

Abstract

Reaction of [UI2(HMPA)4]I with potassium anthracenide gives the unprecedented arenide-sandwich complex U(η6-C14H10)(η4-C14H10)(HMPA)2. CASSCF calculations indicate the U–C bonding to solely consist of π-interactions.

Topology-Dependent Synthesis, Structures, and Bonding Interactions of Uranium Polyarene Complexes

“…These values are consistent with the presence of a uranium(IV) ion with a nonmagnetic ground state, 102 and close to the μ eff of U(η 6 -C 14 H 10 )(η 4 -C 14 H 10 )-(HMPA) 2 (HMPA = OP(NMe 2 ) 3 ) (2.31 μ B at 300 K and 0.42 μ B at 1.8 K). 65 The comparable temperature profiles of Density Functional Theory (DFT) Calculations. In order to probe the electronic structures and bonding interactions of these uranium polyarene complexes, relativistic DFT calculations were performed on the model molecules 4′− 6′ and 8′−11′ with the alkyl substituents on the silicon atoms replaced by hydrogen atoms for simplification.…”

“…A close look at the U−C distances reveals that while the U−C distances for inverse-sandwich uranium arene complexes are within a narrow range, the U−C distances for 5 and 9 vary significantly, with two short U−C contacts to the bridgehead carbon atoms (2.554(4) and 2.556(3) Å for 5; 2.563(2) and 2.593(2) Å for 9) and four long U−C distances (2.829(3)−2.865(3) Å for 5; 2.779(2)−2.865(2) Å for 9). Similar coordination modes have previously been observed in uranium bis(anthracenide) complexes [K(18-crown-6)-(THF) 2 ] 2 [U(η 6 -C 14 H 10 )(η 4 -C 14 H 10 )(μ-OMe)] 2 (two short U−C distances of 2.557(5)−2.571(6) Å and four long U−C distances of 2.766(5)−2.797(5) Å) 64 and U(η 6 -C 14 H 10 )(η 4 -C 14 H 10 )(HMPA) 2 (two short U−C distances of 2.547(5)− 2.594(4) Å and four long U−C distances of 2.746(5)− 2.857(3) Å), 65 as well as rare-earth metal anthracenide complexes. 103−105 Moreover, the anthracene and tetracene in 5 and 9 feature a puckered geometry with a bent angle of 29.1(2) and 22.4(1)°, respectively.…”

Crystal structure and synthesis of the bis(anthracene)dicuprate dianion as the dipotassium salt, [K(tetrahydrofuran)2]2[{Cu(9,10-η2-anthracene)}2], the first anionic arene complex of copper

“…Early on we wondered whether f-block elements would also 'succumb' to this strategy, but unfortunately never examined these elements (Ellis, 2019). In this regard, we would like to point to the exciting recent results of Skye Fortier and co-workers in highly challenging uranium chemistry (Murillo et al, 2021(Murillo et al, , 2022. As mentioned in Section 1, we were also intrigued by early reports of 'anionic copper' (Rieke et al, 1990) and this led to our synthesis and structural characterization of the totally unexpected dicuprate salt, 1, described herein.…”

“…Mononuclear heteroleptic complexes of d-and f-block elements containing M(9,10-� 2 -anthracene) moieties have been structurally authenticated for the Group 3 elements scandium (Ellis et al, 2018;Ghana et al, 2020;Zhu et al, 2023) and lutetium (Roitershtein et al, 1992(Roitershtein et al, , 1993, and the f-block elements thulium (Fedushkin et al, 2001) and thorium (Yu et al, 2020). Unique uranium anthracene complexes containing individual metals bound to both the terminal and central rings of different anthracene ligands have been published recently (Murillo et al, 2021(Murillo et al, , 2022. Dinuclear complexes of scandium (Huang et al, 2011(Huang et al, , 2014, yttrium (Fryzuk et al, 2000), and iron (Hatanaka et al, 2012) containing bridging anthracenes, in which one metal binds to the terminal ring and the other anti to the central ring of anthracene, are also known.…”

Synthesis and comparison of iso-structural f-block metal complexes (Ce, U, Np, Pu) featuring η6-arene interactions

“…[10][11][12][13][14][15][16][17][18][19][20][21][22][23] Of note, f-block metal complexes which contain metal-arene interactions have proven to be highly valuable for understanding bonding and the role of valence orbitals for lanthanides and actinides. [24][25][26][27][28][29][30][31][32] Among this class of molecules, those which feature neutral arene coordinating motifs are of particular interest as these may exhibit covalent participation of the metal in the form of p/d/4 type interactions. 31,[33][34][35][36][37] Such complexes have potential to provide new key insight into f-block bonding modes as has been the case in other areas of the periodic table; for example, the seminal discovery of bis(benzene)chromium, Cr(h 6 -C 6 H 6 ) 2 , by E. O. Fischer, which revolutionized the understanding of transition metal chemistry.…”