David J. H. Emslie

Updated syntheses and/or structural characterizations are provided for previously reported halotitanocene(III) complexes [{Cp ₂ Ti(μ‐X)} ₂ ] (X = Cl ( 1 ), Br ( 2 ), and I ( 3 )), and THF‐coordinated [Cp ₂ Ti(μ‐Cl)(THF)ZnCl(μ‐Cl) ₂ TiCp ₂ ] ( 4 ) was crystallographically characterized. Reactions of 1 with ClAlR ₂ Lewis acids generated the heterobimetallic complexes [Cp ₂ Ti(μ‐Cl) ₂ AlR ₂ ] (R = Cl ( 5a ), Me ( 5b ), Ph ( 5c ), C ₆ F ₅ ( 5d )) and reactions of 1 with M[BAr ₄ ] (M = Na, K or Tl) salts in DME afforded the DME‐coordinated cations [Cp ₂ Ti(κ ² ‐DME)][BAr ₄ ] (Ar = C ₆ F ₅ ( 6a ), 3,5‐C ₆ H ₃ (CF ₃ ) ₂ ( 6b ), 3,5‐C ₆ H ₃ Cl ₂ ( 6c )). Reaction of the titanacyclopropene [Cp ₂ Ti(η ² ‐C ₂ (SiMe ₃ ) ₂ )] with PhC ₂ P ⁱ Pr ₂ afforded the phosphine‐containing titanacyclopropene complex [Cp ₂ Ti(η ² ‐PhC ₂ P ⁱ Pr ₂ )] ( 7 ), and the triisobutylaluminium adduct of this species, [Cp ₂ Ti{η ² ‐PhC ₂ P ⁱ Pr ₂ (Al ⁱ Bu ₃ )}] ( 8 ), was crystallographically characterized. Addition of 2 equiv. of KC ₈ to a solution of the zwitterionic titanocene(III) complex [Cp{η ⁵ :κ ² F ₂ ‐C ₅ H ₄ B(C ₆ F ₅ ) ₃ }Ti] in THF yielded [K(THF) ₃ ][Cp{η ⁵ :κ ¹ C ‐C ₅ H ₄ B(C ₆ F ₅ ) ₂ (C ₆ F ₄ )}Ti(THF)] ( 9 ), likely resulting from 1‐electron reduction to titanium(II) followed by C─F bond oxidative addition to form a titanium(IV) fluoride species, KF elimination, THF coordination, and a second 1‐electron reduction to titanium(III).

Structurally diverse silver perfluoro- tert -butoxide complexes were synthesized bearing phosphinite, aminophosphine, isonitrile, pyridine, bis(amine), bis(phosphine), and mixed phosphine/amine ligands.

Phosphine-coordinated gold( i ) perfluoro- tert -butoxide complexes have been investigated as potential atomic layer deposition (ALD) precursors for elemental gold.

We report a systematic probe of covalency at the boundaries of f-block hard-metal/soft-ligand interactions by employing monoanionic ligands containing formally neutral chalcogen donors to facilitate isostructural comparisons of early to middle trivalent actinides (An = U, Np, Pu, Am) and their near isoradial lanthanide counterparts (Ln = La, Ce, Pr, Nd). The single-crystal structural data on [(AE₂^Ph2)₂M^IIII] (1-M, E = S, M = La, Ce, Pr, Nd, U, Np, Pu, Am; 2-M, E = Se, M = La, Ce, Pr, Nd, Np, Pu, Am; AE₂^Ph2 = 4,5-bis(phenylchalcogenido)-2,7,9,9-tetramethylacridanide) provides metrical definition of the first transuranium actinide selenoether bonds to Np, Pu, and Am as well as the first Pr and Nd selenoether complexes. Additionally, rare examples of transuranium thioether and lanthanum/cerium-selenoether complexes are reported. The shorter metal-chalcogen bonds in the actinide complexes compared to lanthanide congeners suggest stronger covalent interactions, though it becomes less pronounced as the f-block series is traversed to the Am vs Nd comparison. Computational analyses support these findings, showing increased metal-ligand participation in the U, Np, and Pu complexes and further participation of valence shell orbitals when moving from S to Se as the chalcogenoether donor atom.

Reactions of manganese germylene hydride complexes with CO₂ are described, affording formate-substituted germylene and κ²-formatogermyl complexes. Reactions with related unsaturated substrates (a ketone and a carbodiimide) are also discussed.

The manganese germylene-hydride complexes [(dmpe)₂MnH(GeR₂)] (1a: R = Ph, 1b: R = Et) reacted with H₂ (approx. 1.5 atm) to afford the ‘germyl dihdyride’ species [(dmpe)₂MnH₂(GeHR₂)] (2a: R = Ph, 2b: R = Et) as an equilibrium mixture with the starting material (1a–b). In solution, 2a–b exist as a mixture of isomers where the major isomer (71–84%) is a trans hydrogermane hydride complex trans-[(dmpe)₂MnH(HGeHR₂)] (transHGe-2a–b). The minor isomer of 2a–b is tentatively assigned as the cis germyl dihydrogen complex cis-[(dmpe)₂Mn(GeHR₂)(H₂)] (cis-2a–b), possibly in rapid equilibrium with a small amount of the germanate complex [(dmpe)₂Mn(H₂GeHR₂)] (central-2a–b). DFT calculations were employed to gain insight into the nature of bonding in the isomers of 2a–b, and an X-ray crystal structure was obtained for trans-[(dmpe)₂MnH(HGeHEt₂)] (transHGe-2b) which co-crystallized with 1b. Reactions of 1a–b with D₂ suggest a pathway that proceeds via conversion of 1a–b to a 5-coordinate germyl intermediate [(dmpe)₂Mn(GeHR₂)] (A) prior to reaction with H₂/D₂. Providing support for this pathway, intermediate A (R = Ph) was trapped via reactions of 1a with isonitriles, affording the manganese(I) germyl isonitrile complexes [(dmpe)₂Mn(GeHPh₂)(CNR)] (3a: R = ^tBu, 3b: R = o-xylyl, and 3c: R = ⁿBu). These complexes formed as a mixture of cis and trans isomers, and X-ray quality crystals were obtained for cis-3a, cis-3b and trans-3c. Complexes 1a–b also reacted slowly with dinitrogen at room temperature to afford germyl dinitrogen complexes [(dmpe)₂Mn(GeHR₂)(N₂)] (5a: R = Ph, 5b: R = Et). Compounds 5a–b were initially formed as cis isomers, but the trans isomer is the thermodynamic product in each case, and the cis and trans isomers were crystallographically characterized for both 5a and 5b. X-ray crystallography, IR spectroscopy, and DFT calculations were employed to compare metal–dinitrogen bonding in the cis and trans isomers of 5a–b. The silyl dinitrogen derivative [(dmpe)₂Mn(SiHPh₂)(N₂)] (6) was also generated as a mixture of the cis and trans isomers, and the trans isomer was structurally characterized. The trans isomers of 5b and 6 show ⁵⁵Mn–³¹P coupling in the ³¹P{¹H} and ⁵⁵Mn{¹H} NMR spectra, affording 1 : 1 : 1 : 1 : 1 : 1 sextets and 1 : 4 : 6 : 4 : 1 quintets, respectively.

A new diethyl ether adduct of uranium tetrachloride, [UCl₄(Et₂O)₂] (1), along with the previously reported mono‐etherate complex [UCl₄(Et₂O)]_n (2), have been synthesized and characterized by powder X‐ray diffraction, elemental analysis, and in the case of 1, single crystal X‐ray diffraction. Additionally, reaction of anhydrous [UO₂(OAc)₂]_n with HCl in Et₂O/THF was found to afford the uranyl dichloride complex [UO₂Cl₂(THF)₂]₂ (3) in high purity and yield, providing an alternative and convenient entry point into anhydrous uranyl chemistry. Furthermore, comments are provided regarding the literature synthesis of [ThCl₄(dme)₂] via the reaction of [ThCl₄(H₂O)₄] with Me₃SiCl in dme, highlighting important considerations for the compound's preparation in good yield.

This manuscript describes the first unambiguous examples of s-block–telluroether bonding.

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, {(Me₃Si)₃Si}Li(THF)₃ (1), supersilyl sodium, (^tBu₃Si)Na(THF)_n (2, n = 2-3), and trimethylgermyl lithium, {Me₃GeLi(THF)₂}₂ (3), were used for the synthesis of the silyl- and germyl-substituted boranes in this work. Compounds 1 and 2 were synthesized as previously reported, and compound 3 was isolated from the reaction of trimethylgermane with tert-butyl lithium. Compounds 2 and 3 were crystallographically characterized. Reaction of B(NMe₂)Cl₂ with 2 equiv of 1 afforded previously reported {(Me₃Si)₃Si}₂B(NMe₂) (4), whereas reactions of B(NMe₂)Cl₂ or {B(NMe₂)F₂}₂ with excess 2 only afforded the monosilyl boranes (^tBu₃Si)B(NMe₂)X {X = Cl (5) and F (6)}. Reaction of 5 with 0.5 equiv of {Me₃GeLi(THF)₂}₂ (3) provided the first example of a mixed silyl/germyl-substituted borane, (^tBu₃Si)(Me₃Ge)B(NMe₂) (7). Attempts to synthesize (Me₃Ge)₂B(NMe₂) from the 1:1 reaction of B(NMe₂)Cl₂ with {Me₃GeLi(THF)₂}₂ afforded a mixture of two major products, one of which was identified as the tri(germyl)(amido)borate {(Me₃Ge)₃B(NMe₂)}Li(THF)₂ (8); compound 8 was isolated from the 1:1.5 reaction. Reaction of more sterically encumbered B(TMP)Cl₂ with 1 equiv of {Me₃GeLi(THF)₂}₂ afforded the di(germyl)(amido)borane (Me₃Ge)₂B(TMP) (9). Boranes 4, 7, and 9 and borate 8 were crystallographically characterized. The thermal stability and volatility of boranes 4, 7, and 9 was evaluated, the solution reactivity of 4 and 7 with boron trihalides was assessed, and ALD was attempted using 4 in combination with BCl₃ and BBr₃ at 150 and 300 °C.