Silyl- and Germyl-Substituted Boranes: Synthesis and Investigation as Potential Atomic Layer Deposition Precursors.

Boranes featuring bulky hypersilyl or supersilyl groups and/or sterically unencumbered trimethylgermyl substituents were synthesized for investigation as potential precursors for atomic layer deposition (ALD) of elemental boron. The envisaged ALD process would employ a boron trihalide coreactant, exploiting the formation of strong silicon-halogen and germanium-halogen bonds as a driving force. The alkali metal silyl and germyl compounds hypersilyl lithium, {(MeSi)Si}Li(THF) (), supersilyl sodium, (BuSi)Na(THF) (, = 2-3), and trimethylgermyl lithium, {MeGeLi(THF)} (), were used for the synthesis of the silyl- and germyl-substituted boranes in this work.

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 comparison of the coordination behaviour of RPCHBMe (R = Me Ph) ambiphilic ligands with late transition metals.

A new synthesis that avoids the use of MePH is reported for (MePCHBMe), and this method was extended to the synthesis of (PhPCHBMe). The ligand precursor (MePCHBMe) did not react with [{M(μ-Cl)(cod)}] (cod = 1,5-cyclooctadiene; M = Ir and Rh) or [PtCl(cod)] at room temperature. However, after 12-48 hours at 65-70 °C, these reactions afforded (a) [Ir(cod)(μ-Cl)(MePCHBMe)] (1), (b) an equilibrium mixture of (MePCHBMe), [{Rh(μ-Cl)(cod)}] and [Rh(cod)(μ-Cl)(MePCHBMe)] (2), and (c) -[Pt(μ-Cl)(MePCHBMe)] (3), respectively.

Reactions of [(dmpe)MnH(CH)] with hydrogermanes to form germylene, germyl, hydrogermane, and germanide complexes.

Reactions of the ethylene hydride complex -[(dmpe)MnH(CH)] (1) with secondary hydrogermanes HGeR at 55-60 °C afforded the base-free terminal germylene hydride complexes -[(dmpe)MnH(GeR)] (R = Ph; 2a, R = Et; 2b). Room temperature reactions of 2a or 2b with an excess of the primary hydrogermanes HGeR' (R' = Ph or Bu) afforded -[(dmpe)MnH(GeHR')] (R' = Ph; 3a, R' = Bu; 3b) in rapid equilibrium with small amounts of 2a/b, as well as the digermyl hydride complex -[(dmpe)MnH(GeHR')] {R' = Ph (4a) or Bu (4b)} and the -hydrogermane germyl complex -[(dmpe)Mn(GeHR')(HGeHR')] {R' = Ph (5a) or Bu (5b)}. Pure 3b was isolated from the reaction of 2b with HGeBu, whereas 3a decomposed readily in solution in the absence of free HGePh, and a pure bulk sample was not obtained.

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.