Thorium(IV) and Uranium(IV) Thioether and Selenoether Complexes: Synthesis and An-ER (E = S, Se) Bonding Comparison.

Reactions of the rigid thioether- and selenoether-containing ligand salts [{Li(AE)}] (E = S or Se; AE = 4,5-bis(phenylchalcogenido)-2,7,9,9-tetramethylacridanide) with ThCl(dme) or UCl (for E = Se) afforded the actinide chalcogenoether complexes [(AE)ThCl] (E = S (), Se ()), and [(ASe)UCl] (). X-ray crystal structures of - revealed tetravalent actinide cations complexed to two κ-coordinated AE ligands, with Th-ER and U-ER distances below the sum of the covalent radii. Complexes - provide extremely rare examples of thorium-thioether, thorium-selenoether, and uranium-selenoether bonds, and and contain the shortest known Th-SR and Th-SeR distances.

A Synthetic, Structural, Spectroscopic, and Computational Study of Alkali Metal-Thioether, -Selenoether, and -Telluroether Interactions.

The rigid thioether- and selenoether-containing pro-ligands, 4,5-bis(phenylsulfido)-2,7,9,9-tetramethylacridan (H[AS] ()) and 4,5-bis(phenylselenido)-2,7,9,9-tetramethylacridan (H[ASe] ()), were deprotonated with one equiv of BuLi to afford dimeric lithium complexes [Li(AE)] (E = S (), Se ()) or with one equiv of KCHPh to afford the previously reported potassium complexes [K(AS)(dme)] () and [K(ASe)(dme)] (). Attempts to prepare a direct telluroether analogue of compounds - were unsuccessful. However, the bulky selenoether- and telluroether-containing pro-ligands 4,5-bis(2,4,6-triisopropylphenylselenido)-2,7,9,9-tetramethylacridan (H[ASe] ()) and 4,5-bis(2,4,6-triisopropylphenyltellurido)-2,7,9,9-tetramethylacridan (H[ATe] ()) were accessed via the reaction of 4,5-dibromo-2,7,9,9-tetramethylacridan with three equiv of BuLi, followed by the addition of two equiv of the corresponding diaryl dichalcogenide and quenching with dilute HCl.

Group 3 dialkyl complexes of a rigid monoanionic NNN-donor pincer ligand: synthesis, structures, unexpected reactivity with CPh, and hydroamination catalysis.

Palladium-catalyzed coupling of 4,5-dibromo-2,7,9,9-tetramethylacridan with two equivalents of 1,3-diisopropylimidazolin-2-imine afforded 4,5-bis(1,3-diisopropylimidazolin-2-imino)-2,7,9,9-tetramethylacridan, H[AII]. Reaction of the H[AII] pro-ligand with one equivalent of [M(CHSiMe)(THF)] (M = Y or Sc) yielded the base-free neutral dialkyl complexes [(AII)M(CHSiMe)] {M = Y (1) and Sc (2)}. The rigid AII pincer ligand affords a similar steric profile to the previously reported XA pincer ligand, but is monoanionic rather than dianionic.

Uranium(IV) Thio- and Selenoether Complexes: Syntheses, Structures, and Computational Investigation of U-ER Interactions.

Rigid thioether- and selenoether-containing pincer proligands H[AS ] (1) and H[ASe ] (2) were synthesized, and deprotonation provided the potassium salts [K(AS )(dme)] (3) and [K(ASe )(dme) ] (4). Reaction of two equivalents of 3 or 4 with [UI (dioxane) ] afforded the uranium thioether complex [(AS ) UI ] (5) and the first example of a uranium-selenoether complex, [(ASe ) UI ] (6). X-ray structures revealed distorted square antiprismatic geometries in which the AE ligands are κ -coordinated.