Yttrium Anilido Hydride: Synthesis, Structure, and Reactivity

The synthesis, structure, and reactivity of the yttrium anilido hydride [LY(NH(DIPP))(μ-H)]₂ (<b>3</b>; L = [MeC(N(DIPP))CHC(Me)(NCH₂CH₂NMe₂)]⁻, DIPP = 2,6-^<i>i</i>Pr₂C₆H₃)) are reported. The protonolysis reaction of the yttrium dialkyl [LY(CH₂SiMe₃)₂] (<b>1</b>) with 1 equiv of 2,6-diisopropylaniline gave the yttrium anilido alkyl [LY(NH(DIPP))(CH₂SiMe₃)] (<b>2</b>), and a subsequent σ-bond metathesis reaction of <b>2</b> with 1 equiv of PhSiH₃ offered the yttrium anilido hydride <b>3</b>. The structure of <b>3</b> was characterized by X-ray crystallography, which showed that the complex is a μ-H dimer. <b>3</b> shows high reactivity toward a variety of unsaturated substrates, including imine, azobenzene, carbodiimide, isocyanide, ketone, and Mo(CO)₆, giving some structurally intriguing products

1‑Methyl Boratabenzene Yttrium Alkyl: A Highly Active Catalyst for Dehydrocoupling of Me₂NH·BH₃

Catalytic activity of rare-earth metal complexes for dehydrocoupling of Me₂NH·BH₃ is deeply ligand- and metal ion-dependent, and 1-methyl boratabenzene yttrium alkyl shows very high activity for the reaction (TOF > 1000 h^–1). The transformation of Me₂NH·BH₃ into [Me₂N–BH₂]₂ proceeds through an intermediate Me₂NH–BH₂–NMe₂–BH₃

Reversible Addition of the Si–H Bond of Phenylsilane to the ScN Bond of a Scandium Terminal Imido Complex

The facile and reversible addition of the Si–H bond of phenylsilane to the ScN bond of the scandium terminal imido complex [LScNDIPP­(DMAP)] (<b>1</b>; L  [MeC­(N­(DIPP))­CHC­(Me)­(NCH₂CH₂NMe)]⁻, DIPP = 2,6-^<i>i</i>Pr₂C₆H₃) is reported. The reaction gives the scandium anilido hydride [LSc­(H)­(N­(DIPP)­(SiH₂Ph))] (<b>2</b>), and a labeling experiment shows a rapid σ-bond metathesis between Sc–H of the formed scandium anilido hydride and Si–H of phenylsilane during the reaction. <b>2</b> was trapped by an insertion reaction with diphenylcarbodiimide, giving the stable scandium anilido amidinate [LSc­(N­(DIPP)­(SiH₂Ph))­(κ²(<i>N</i>,<i>N</i>′)-PhNCHNPh)] (<b>3</b>). Furthermore, the scandium terminal imido complex can efficiently catalyze the hydrosilylation of <i>N</i>-benzylidenepropan-1-amine. The reaction was completed within 2 h at 50 °C with 5 mol % of catalyst loading and highly selectively produced the monoaminosilane

C–P or C–H Bond Cleavage of Phosphine Oxides Mediated by an Yttrium Hydride

Reactions of the yttrium anilido hydride [LY­(NH­(DIPP))­(μ-H)]₂ (<b>1</b>; L = [MeC­(N­(DIPP))­CHC­(Me)­(NCH₂CH₂NMe₂)]⁻, DIPP = 2,6-ⁱPr₂C₆H₃)) with three phosphine oxides and two phosphine sulfides are reported. The reaction of <b>1</b> with Ph₃PO gives C–P bond cleavage and an yttrium anilido phosphinoyl complex, while those with R₂MePO (R = Me, Ph) result in C–H bond cleavage and two yttrium anilido alkyl complexes. <b>1</b> also reacted with R₃PS (R = Me, Ph), which demonstrated P–S bond cleavage via hydride-based reduction and gave an yttrium anilido sulfide

Electronic Structures and Unusual Chemical Bonding in Actinyl Peroxide Dimers [An₂O₆]²⁺ and [(An₂O₆)(12-crown‑4 ether)₂]²⁺ (An = U, Np, and Pu)

As known, actinyl peroxides play important roles in environmental transport of actinides, and they have strategic importance in the application of nuclear industry. Compared to the most studied uranyl peroxides, the studies of transuranic counterparts are still few, and more information about these species is needed. In this work, experimentally inspired actinyl peroxide dimers ([An2O6]2+, An = U, Np, and Pu) have been studied and analyzed by using density functional theory and multireference wave function methods. This study determines that the three [An2O6]2+ have unique electronic structures and oxidation states, as [(UVIO2)2(O2)2–]2+, [(NpVIIO2)2(O2–)2]2+, and mixed-valent [(PuVI/VO2)2(O2)1–]2+. This study demonstrates the significance of two bridging oxo ligands with at most four electron holes availability in ionically directing actinyl and resulting in the unusual multiradical bonding in [(PuVI/VO2)2(O2)1–]2+. In addition, thermodynamically stable 12-crown-4 ether (12C4) chelated [(An2O6)(12C4)2]2+ complexes have been predicted, that could maintain these unique electronic structures of [An2O6]2+, where the An ← O12C4 dative bonding shows a trend in binding capacity of 12C4 from κ4 (U) to κ3 (Np) and κ4 (Pu). This study reveals the interesting electronic character and bonding feature of a series of early actinide elements in peroxide complexes, which can provide insights into the intrinsic stability of An-containing species

Elucidating Solution-State Coordination Modes of Multidentate Neutral Amine Ligands with Group‑1 Metal Cations: Variable-Temperature NMR Studies

Multidentate neutral amine ligands play vital roles in coordination chemistry and catalysis. In particular, these ligands are used to tune the reactivity of Group-1 metal reagents, such as organolithium reagents. Most, if not all, of these Group-1 metal reagent-mediated reactions occur in solution. However, the solution-state coordination behaviors of these ligands with Group-1 metal cations are poorly understood, compared to the plethora of solid-state structural studies based on single-crystal X-ray diffraction (SCXRD) studies. In this work, we comprehensively mapped out the coordination modes with Group-1 metal cations for three multidentate neutral amine ligands: tridentate 1,4,7-trimethyl-1,4,7-triazacyclononane (Me3TACN), tetradentate tris[2-(dimethylamino)ethyl]amine (Me6Tren), and hexadentate N,N′,N″-tris-(2-N-diethylaminoethyl)-1,4,7-triaza-cyclononane (DETAN). The macrocycles in the Me3TACN and DETAN are identified as the rigid structural directing motif, with the sidearms of DETAN providing flexible “on-demand” coordination sites. In comparison, the Me6Tren ligand features more robust coordination, with the sidearms less likely to undergo the decoordinating–coordinating equilibrium. This work will provide a guidance for coordination chemists in applying these three ligands, in particular, the new DETAN ligand to design metal complexes which suit their purposes