Ashley Wooles

• University of Nottingham

Procedures for activating and degrading compounds containing carbon-halogen bonds are highly sought after due to the environmental persistence and potential hazards of such compounds. Such activations are challenging because of the high stability of these bonds, particularly those with C-F bonds. Here, we report on the activation of carbon-halogen...

Although two examples of σ-bonded trans-bent [RSbSbR]•– (R = bulky organo- or Ga-groups) that formally contain the Sb2•3– radical trianion moiety are known in p-block chemistry, d- or f-element Sb2•3– radical trianion complexes, with or without R-substituents, have remained elusive. Here, we report that reduction of a 77:23 mix of [{Th(TrenTIPS)}2(...

Reactions between [(TrenTIPS)UVIN] (1, TrenTIPS = {N(CH2CH2NSiPri3)3}3) and [MII(5-C5R5)2] (M/R = Cr/H, Mn/H, Fe/H, Ni/H) were intractable, but M/R = Co/H or Co/Me afforded [(TrenTIPS)UV=N-(1:4-C5H5)CoI(5-C5H5)] (2) and [(TrenTIPS)UIV-NH2] (3), respectively....

The paramagnetism of f-block ions has been exploited in chiral shift reagents and magnetic resonance imaging, but these applications tend to focus on ¹H NMR shifts as paramagnetic broadening makes less sensitive nuclei more difficult to study. Here we report a solution and solid-state (ss) ²⁹Si NMR study of an isostructural series of locally D3h-sy...

The paramagnetism of f-block ions has been exploited in chiral shift reagents and magnetic resonance imaging, but these applications tend to focus on 1H NMR shifts as paramagnetic broadening makes less sensitive nuclei more difficult to study. Here we report a solution and solid-state (ss) 29Si NMR study of an isostructural series of locally D3h-sy...

Reaction of the cesium antimonide complex [Cs(18C6)2][SbH2] (1, 18C6 = 18-crown-6 ether) with the triamidoamine actinide separated ion pairs [An(TrenTIPS)(L)][BPh4] (TrenTIPS = {N(CH2CH2NSiⁱPr3)3}3–; An/L = Th/DME (2Th); U/THF (2U)) affords the triactinide undeca-antimontriide Zintl clusters [{An(TrenTIPS)}3(μ3-Sb11)] (An = Th (3Th), U (3U)) by deh...

We introduce the boryloxide ligand {(HCNDipp)2BO}⁻ (NBODipp, Dipp = 2,6-di-isopropylphenyl) to actinide chemistry. Protonolysis of [U{N(SiMe3)2}3] with 3 equiv of NBODippH produced the uranium(III) tris(boryloxide) complex [U(NBODipp)3] (1). In contrast, treatment of UCl4 with 3 equiv of NBODippK in THF at room temperature or reflux conditions prod...

There is continued burgeoning interest in metal–metal multiple bonding to further our understanding of chemical bonding across the periodic table. However, although polar covalent metal–metal multiple bonding is well known for the d and p blocks, it is relatively underdeveloped for actinides. Homometallic examples are found in spectroscopic or full...

Organoplutonium chemistry was established in 1965, yet structurally authenticated plutonium–carbon bonds remain rare being limited to π-bonded carbocycle and σ-bonded isonitrile and hydrocarbyl derivatives. Thus, plutonium-carbenes, including alkylidenes and N-heterocyclic carbenes (NHCs), are unknown. Here, we report the preparation and characteri...

We report the synthesis and characterisation of thorium(IV), uranium(III), and uranium(IV) complexes supported by a sterically demanding triamidoamine ligand with N‐diphenyl‐tert‐butyl‐silyl substituents. Treatment of ThCl4(THF)3.5 or UCl4 with [Li3(TrenDPBS)] (TrenDPBS={N(CH2CH2NSiPh2But)3}³⁻) afforded [An(TrenDPBS)Cl] (An=Th, 1Th; U, 1U). Complex...

Structurally characterised U−Sb bonds are rare. Here, the synthesis and characterisation of [U(TrenDMBS){Sb(H)C(H)(SiMe3)2}] (5, TrenDMBS=N(CH2CH2NSiMe2But)3) and [{U(TrenTIPS)}2{Sb3(μ6‐Li)(μ‐Li[THF]2)3Sb3}] (6, TrenTIPS=N(CH2CH2NSiPrⁱ3)3) are reported. Complex 5 is an unprecedented primary stibinide actinide complex and 6 can be formulated as cont...

We report the synthesis and characterisation of a series of M(IV) substituted cyclopentadienyl hypersilanide complexes of the general formula [M(CpR)2{Si(SiMe3)3}(X)] (M = Hf, Th; CpR = Cp', {C5H4(SiMe3)} or Cp'', {C5H3(SiMe3)2-1,3}; X = Cl, C3H5). The separate salt metathesis reactions of [M(CpR)2(Cl)2] (M = Zr or Hf, CpR = Cp'; M = Hf or Th, CpR...

The salt metathesis reactions of the yttrium methanediide iodide complex [Y(BIPM)(I)(THF)2] (BIPM = {C(PPh2NSiMe3)2}) with the group 1 silanide ligand-transfer reagents MSiR3 (M = Na, R3 = tBu2Me or tBu3; M = K, R3 = (SiMe3)3) gave the yttrium methanediide silanide complexes [Y(BIPM)(SitBu2Me)(THF)] (1), [Y(BIPM)(SitBu3)(THF)] (2), and [Y(BIPM){Si(...

We report the synthesis of the U(iii) bis(cyclopentadienyl) hypersilanide complex [U(Cp'')2{Si(SiMe3)3}] (Cp'' = {C5H3(SiMe3)2-1,3}), together with isostructural lanthanide and group 4 M(iii) homologues, in order to meaningfully compare metal-silicon bonding between early d- and f-block metals. All complexes were characterised by a combination of N...

We report the direct synthesis of the terminal pnictidenes [An(TrenTCHS)(PnH)][M(2,2,2‐cryptand)] (TrenTCHS={N(CH2CH2NSiCy3)3}³⁻; An/Pn/M=Th/P/Na 5, Th/As/K 6, U/P/Na 7, U/As/K 8) and their conversion to the pnictides [An(TrenTCHS)(PnH2)] (An/Pn=Th/P 9, Th/As 10, U/P 11, U/As 12). Use of the super‐bulky TrenTCHS ligand was essential to accessing co...

We report the direct synthesis of the terminal pnictidenes [An(Tren TCHS )(PnH)][M(2,2,2‐cryptand)] (Tren TCHS = {N(CH 2 CH 2 NSiCy 3 )} 3‐ ; An/Pn/M = Th/P/Na 5 , Th/As/K 6 , U/P/Na 7 , U/As/K 8 ) and their conversion to the pnictides [An(Tren TCHS )(PnH 2 )] (An/Pn = Th/P 9 , Th/As 10 , U/P 11 , U/As 12 ). Use of the super‐bulky Tren TCHS ligand...

Treatment of [UIV(N3)(TrenTIPS)] (1, TrenTIPS = {N(CH2CH2NSiPri3)3}3-) with excess Li resulted in the isolation of [{UIV(μ-NLi2)(TrenTIPS)}2] (2), which exhibits a diuranium(IV) 'diamond-core' dinitride motif. Over-reduction of 1 produces [UIII(TrenTIPS)] (3), and together with known [{UV(μ-NLi)(TrenTIPS)}2] (4) an overall reduction sequence 1 → 4...

Since the advent of organotransuranium chemistry six decades ago, structurally verified complexes remain restricted to π-bonded carbocycle and σ-bonded hydrocarbyl derivatives. Thus, transuranium-carbon multiple or dative bonds are yet to be reported. Here, utilizing diphosphoniomethanide precursors we report the synthesis and characterization of t...

We report the synthesis and characterisation of a series of rare‐earth mesoionic carbene complexes, [RE{N(SiMe3)2}3{CN(Me)C(Me)N(Me)CH}] (3RE, RE=Sc, Ce, Pr, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), greatly expanding the limited library of f‐block mesoionic carbene complexes. These complexes were prepared by treatment of the parent RE‐triamides wit...

We report the synthesis and characterization of uranium(IV) and thorium(IV) mesoionic carbene complexes [An{N(SiMe3)2}2(CH2SiMe2NSiMe3){MIC}] (An = U, 4U and Th, 4Th; MIC = {CN(Me)C(Me)N(Me)CH}), which represent rare examples of actinide mesoionic carbene linkages and the first example of a thorium mesoionic carbene complex. Complexes 4U and 4Th we...

Neptunium was the first actinide element to be artificially synthesized, yet, compared with its more famous neighbours uranium and plutonium, is less conspicuously studied. Most neptunium chemistry involves the neptunyl di(oxo)-motif, and transuranic compounds with one metal–ligand multiple bond are rare, being found only in extended-structure oxid...

Metal-metal bonding is a widely studied area of chemistry1–3, and has become a mature field spanning numerous d transition metal and main group complexes4–7. In contrast, actinide-actinide bonding is predicted to be weak⁸, being currently restricted to spectroscopically-detected gas-phase U2 and Th29,10, U2H2 and U2H4 in frozen matrices at 6-7 Kelv...

Disproportionation, where a chemical element converts its oxidation state to two different ones, one higher and one lower, underpins the fundamental chemistry of metal ions. The overwhelming majority of uranium disproportionations involve uranium(III) and (V), with a singular example of uranium(IV) to uranium(V/III) disproportionation known, involv...

A fundamental part of characterizing any metal complex is understanding its electronic ground state, for which magnetometry provides key insight. Most uranium(IV) complexes exhibit low-temperature magnetic moments tending to zero, consistent with a non-degenerate spin-orbit ground state. However, there is a growing number of uranium(IV) complexes w...

Room temperature reaction of the uranium(iv)-carbene [U{C(SiMe3)(PPh2)}(BIPMTMS)(μ-Cl)Li(TMEDA)(μ-TMEDA)0.5]2 (1, BIPMTMS = C(PPh2NSiMe3)2) with white phosphorus (P4) produces the organo-P5 compound [P5{C(SiMe3)(PPh2)}2][Li(TMEDA)2] (2) and the uranium(iv)-methanediide [U{BIPMTMS}{Cl}{μ-Cl}2{Li(TMEDA)}] (3). This is an unprecedented example of coop...

Separate reactions of [Th{N(CH2CH2NSiMe2But)2(CH2CH2NSi(Me)(But)(-CH2)]2 (1) with [Re(5-C5H5)2(H)] (2) or [Ru(5-C5H5)(H)(CO)2] (3) produced, by alkane elimination, [Th(TrenDMBS)Re(5-C5H5)2] (ThRe, TrenDMBS = {N(CH2CH2NSiMe2But)3}3-), and [Th(TrenDMBS)Ru(5-C5H5)(CO)2] (ThRu), which were isolated in crystalline yields of 71 and 62%, respectively. Com...

The first isolation and structural characterization of an f-element dinitrogen complex was reported in 1988, but an f-element complex with the first heavier group 15 homologue diphosphorus has to date remained unknown. Here, we report the synthesis of a side-on bound diphosphorus complex of uranium(IV) using a 7λ3-(dimethylamino)phosphadibenzonorbo...

Treatment of the new methanediide-methanide complex [Dy(SCS)(SCSH)(THF)] (1Dy, SCS = {C(PPh2S)2}²⁻) with alkali metal alkyls and auxillary ethers produces the bis-methanediide complexes [Dy(SCS)2][Dy(SCS)2(K(DME)2)2] (2Dy), [Dy(SCS)2][Na(DME)3] (3Dy) and [Dy(SCS)2][K(2,2,2-cryptand)] (4Dy). For further comparisons, the bis-methanediide complex [Dy(...

We report a D 4h @Dy single-molecule magnet (SMM) with a U eff energy barrier of 1565 K, one of the highest energy barriers for any 6-coordinate lanthanide SMM.

The reduction chemistry of the newly emerging 2‐phosphaethynolate (OCP)⁻ is not well explored, and many unanswered questions remain about this ligand in this context. We report that reduction of [Th(TrenTIPS)(OCP)] (2, TrenTIPS=[N(CH2CH2NSiPrⁱ3)]³⁻), with RbC8 via [2+2+1] cycloaddition, produces an unprecedented hexathorium complex [{Th(TrenTIPS)}6...

A series of Ni complexes [Ni(Cl)2(PR3)2] with R = Me (1-Me), nPr (1-nPr), and nBu (1-nBu) and nickelocenes [Ni(5-C5H4R′)2] with R′ = H (2-H), Me (2-Me), and SiMe3 (2-SiMe3) were synthesized and characterized. From these complexes, the synthesis of the Ni complexes [NiCl(PR3)(5-C5H4R′)] R = Me, R′ = H (3-Me), R= nBu, R′ = H (3-nBu), R = nPr, R′ = H...

A reaction with the overall appearance of (OCP)⁻ concerted cleavage is revealed to proceed through a [2+2+1]‐cycloaddition reaction intermediate, introducing an unprecedented example of (OCP)⁻ cycloaddition under reducing conditions to the established neutral and oxidative cycloaddition classes of (OCP)⁻ reactivity. Abstract The reduction chemistr...

We report the synthesis and characterisation of isostructural thorium(iv)- and uranium(iv)-silanide actinide (An) complexes, providing an opportunity to directly compare Th-Si and U-Si chemical bonds. Quantum chemical calculations show significant and surprisingly similar An%:Si%, 7s-, 6d-, and 5f-orbital contributions from both elements in polaris...

We report the synthesis and characterisation of isostructural thorium(IV)- and uranium(IV)- silanide complexes, providing the first structurally authenticated Th-Si bond and a rare example of a molecular U-Si bond. These complexes therefore present the first opportunity to directly compare the chemical bonding of Th-Si and U-Si bonds. Quantum chemi...

Treatment of [Ph3EMe][I] with [Na{N(SiMe3)2}] affords the ylides [Ph3E=CH2] (E=As, 1As; P, 1P). For 1As this overcomes prior difficulties in the synthesis of this classical arsonium‐ylide that have historically impeded its wider study. The structure of 1As has now been determined, 45 years after it was first convincingly isolated, and compared to 1...

The reaction of [UO2(μ-Cl)4{K(18-crown-6)}2] with [{N(CH2CH2NSiPri3)3}Li3] gives [{UO(μ-NCH2CH2N[CH2CH2NSiPri3]2)}2] (1), [{(LiCl)(KCl)(18-crown-6)}2] (2), and [LiOSiPri3] (3) in a 1:2:2 ratio. The formation of the oxo-imido 1 involves the cleavage of a N-Si bond and the activation of one of the usually robust U═O bonds of uranyl(VI), resulting in...

We report the synthesis and structural authentication of the ditungsten decarbonyl dianion in [(OC)5W-W(CO)5][K(18-crown-6)(THF)2]2 (1), completing the group 6 dianion triad over half a century since the area began. The W-W bond is long [3.2419(8) Å] and, surprisingly, in the solid-state the dianion adopts a D4h eclipsed rather than D4d staggered g...

Despite the vast array of η n -carbocyclic C5-8 complexes reported for actinides, cyclobutadienyl (C4) remain exceedingly rare, being restricted to six uranium examples. Here, overcoming the inherent challenges of installing highly reducing C4-ligands onto actinides when using polar starting materials such as halides, we report that reaction of [T...

A new route to the classical ylide Ph3As=CH2 resolves previous difficulties in its synthesis and isolation. Its structural authentication, 45 years after it was first made, confirms that the ylide is pyramidal not planar, and it enables the synthesis of a uranium–arsonium–carbene, the first structurally characterised example of an arsonium–carbene...

Reaction of [Li2{C4(SiMe3)4}(THF)2] (1) with [U(η5-C5Me5)I2(THF)] (2) produced the oxo-centered homotrimetallic uranium-pentamethylcyclopentadienyl complex [{U(η5-C5Me5)(μ-I)2}3{μ3-O}{Li(THF)3}0.5]2[Li(THF)4] (3) as the only isolable product in a very low yield. In contrast, reaction of 2 with [Mg{C4(SiMe3)4}(THF)3] (4) produced the oxo-centered ho...

Despite their importance as mechanistic models for heterogeneous Haber Bosch ammonia synthesis from dinitrogen and dihydrogen, homogeneous molecular terminal metal-nitrides are notoriously unreactive towards dihydrogen, and only a few electron-rich, low-coordinate variants demonstrate any hydrogenolysis chemistry. Here, we report hydrogenolysis of...

Despite there being numerous examples of f‐element compounds supported by cyclopentadienyl, arene, cycloheptatrienyl, and cyclooctatetraenyl ligands (C5–8), cyclobutadienyl (C4) complexes remain exceedingly rare. Here, we report that reaction of [Li2{C4(SiMe3)4}(THF)2] (1) with [U(BH4)3(THF)2] (2) gives the pianostool complex [U{C4(SiMe3)4}(BH4)3][...

Klavierstuhlkomplex: Das erste Beispiel eines Halbsandwich‐Cyclobutadienylkomplexes eines f‐Elements wird beschrieben, das zugleich erst das zweite Beispiel eines Actinoid‐Cyclobutadienylkomplexes ist. DFT‐Rechnungen zufolge dominiert eine U‐C‐π‐Bindung, ohne δ‐Bindungsanteil. Abstract Despite there being numerous examples of f‐element compounds s...

Little is known about the chemistry of the 2‐arsaethynolate anion, but to date it has exclusively undergone fragmentation reactions when reduced. Herein, we report the synthesis of [U(TrenTIPS)(OCAs)] (2, TrenTIPS=N(CH2CH2NSiiPr3)3), which is the first isolable actinide‐2‐arsaethynolate linkage. UV‐photolysis of 2 results in decarbonylation, but th...

During our attempts to prepare paddlewheel actinide-molybdenum complexes of the type [(X)An(MesNPR2)3Mo(CO)3] (Mes= 2,4,6-trimethylphenyl; X = Cl or I; An = U or Th; R = iPr or Ph) we have found that under certain conditions acetonitrile insertion reactions occur to give the heterobimetallic bridging ketimido species [ClAn(μ-MesNPiPr2)2(μ-MesNPiPr2...

Although the chemistry of uranium-ligand multiple bonding is burgeoning, analogous complexes involving other actinides such as thorium remain rare and there are not yet any terminal thorium nitrides outside of cryogenic matrix isolation conditions. Here, we report evidence that reduction of a thorium-azide produces a transient Th≡N triple bond, but...

A fundamental bonding model in coordination and organometallic chemistry is the synergic, donor–acceptor interaction between a metal and a neutral π-acceptor ligand in which the ligand σ donates to the metal, which π back-bonds to the ligand. This interaction typically involves a metal with an electron-rich, mid-, low- or even negative oxidation st...

The chemistry of 2‐phosphaethynolate is burgeoning, but there remains much to learn about this ligand, for example its reduction chemistry is scarce as this promotes P‐C‐O fragmentations or couplings. Here, we report that reduction of [U(TrenTIPS)(OCP)] (TrenTIPS=N(CH2CH2NSiPrⁱ3)3) with KC8/2,2,2‐cryptand gives [{U(TrenTIPS)}2{μ‐η²(OP):η²(CP)‐OCP}]...

The chemistry of 2‐phosphaethynolate is burgeoning, but there remains much to learn about this ligand, for example its reduction chemistry is scarce as this promotes P‐C‐O fragmentations or couplings. Here, we report that reduction of [U(TrenTIPS)(OCP)] (TrenTIPS = N(CH2CH2NSiPri3)3) with KC8/2,2,2‐cryptand gives [{U(TrenTIPS)}2{μ‐η2(OP):η2(CP)‐OCP...

Although reductive cleavage of dinitrogen (N2) to nitride (N³⁻) and hydrogenation with dihydrogen (H2) to yield ammonia (NH3) is accomplished in heterogeneous Haber–Bosch industrial processes on a vast scale, sequentially coupling these elementary reactions together with a single metal complex remains a major challenge for homogeneous molecular com...

Although reductive cleavage of dinitrogen (N2) to nitride (N3‐) and hydrogenation with dihydrogen (H2) to yield ammonia (NH3) is accomplished in heterogeneous Haber Bosch industrial processes on a vast scale, sequentially coupling these elementary reactions together with a single metal complex remains a major challenge for homogeneous molecular com...

Molecular uranium-nitrides are now well known, but there are no isolable molecular thorium-nitrides outside of cryogenic matrix isolation experiments. We report that treatment of [M(TrenDMBS)(I)] (M = U, 1; Th, 2; TrenDMBS = {N(CH2CH2NSiMe2Bu t )3}3-) with NaN3 or KN3, respectively, affords very rare examples of actinide molecular square and trian...

FEUDAL (f’s essentially unaffected, d’s accommodate ligands) is a longstanding bonding model in actinide chemistry, in which metal-ligand binding uses 6d-orbitals, with the 5f remaining non-bonding. The inverse-trans-influence (ITI) is a case where the model may break down, and it has been suggested that ionic and covalent effects work synergistica...

FEUDAL (f's essentially unaffected, d's accommodate ligands) is a longstanding bonding model in actinide chemistry, in which metal-ligand binding uses 6d-orbitals, with the 5f remaining non-bonding. The inverse-trans-influence (ITI) is a case where the model may break down, and it has been suggested that ionic and covalent effects work synergistica...

We report the preparation of four heterobimetallic uranium- and thorium-molybdenum paddlewheel complexes. The characterisation data calculations suggest the presence of Mo→An σ-interactions in all cases. These complexes represent unprecedented actinide-group...

Despite the fact that non-aqueous uranium chemistry is over 60 years old, most polarised-covalent uranium-element multiple bonds involve formal uranium oxidation states IV, V, and VI. The paucity of uranium(III) congeners is because, in common with metal-ligand multiple bonding generally, such linkages involve strongly donating, charge-loaded ligan...

We report the preparation of a range of alkali metal uranyl(VI) tri- bis(silyl)amide complexes [{M(THF) x}{(μ-O)U(O)(N″)3}] (1M) (N″ = {N(SiMe3)2}-, M = Li, Na, x = 2; M = K, x = 3; M = K, Rb, Cs, x = 0) containing electrostatic alkali metal uranyl-oxo interactions. Reaction of 1M with 2,2,2-cryptand or 2 equiv of the appropriate crown ether result...

Reaction of the uranium silyl‐phosphino‐carbene complex [U{C(SiMe3)(PPh2)}(BIPM)(μ‐Cl)Li(TMEDA)(μ‐TMEDA)0.5]2 (1, BIPM = C(PPh2NSiMe3)2; TMEDA = Me2NCH2CH2NMe2) with the rhodium chloride compound [Rh(μ‐Cl)(COD)]2 (COD = cyclo‐octadiene) affords the unprecedented heterotrimetallic UIV‐RhI2 complex [U(Cl)2{C(PPh2NSiMe3)(PPh[C6H4]NSiMe3)}{Rh(COD)}{Rh(...

We report unprecedented silyl-phosphino-carbene complexes of uranium(IV), where before all covalent actinide-carbon double bonds were stabilised by phosphorus(V) substituents or restricted to matrix isolation experiments. Conversion of [U(BIPMTMS)(Cl)(μ-Cl)2Li(THF)2] (1, BIPMTMS = C(PPh2NSiMe3)2) to [U(BIPMTMS)(Cl){CH(Ph)(SiMe3)}] (2), and addition...

We report unprecedented silyl-phosphino-carbene complexes of uranium(IV), where before all covalent actinide-carbon double bonds were stabilised by phosphorus(V) substituents or restricted to matrix isolation experiments. Conversion of [U(BIPMTMS)(Cl)(μ-Cl)2Li(THF)2] (1, BIPMTMS = C(PPh2NSiMe3)2) to [U(BIPMTMS)(Cl){CH(Ph)(SiMe3)}] (2), and addition...

Reaction of the uranium silyl‐phosphino‐carbene complex [U{C(SiMe3)(PPh2)}(BIPM)(μ‐Cl)Li(TMEDA)(μ‐TMEDA)0.5]2 (1, BIPM = C(PPh2NSiMe3)2; TMEDA = Me2NCH2CH2NMe2) with the rhodium chloride compound [Rh(μ‐Cl)(COD)]2 (COD = cyclo‐octadiene) affords the unprecedented heterotrimetallic UIV‐RhI2 complex [U(Cl)2{C(PPh2NSiMe3)(PPh[C6H4]NSiMe3)}{Rh(COD)}{Rh(...

We report unprecedented catalytic reduction of N2 to NH3 by a molecular Ti complex, thus now adding an early d‐block metal to the small group of mid‐ and late‐d‐block metals (Mo, Fe, Ru, Os, Co) that are capable of executing catalytic production of NH3 by N2 reduction and protonolysis under homogeneous, abiological conditions. Under Ar, reduction o...

We report unprecedented catalytic reduction of N2 to NH3 by a molecular Ti complex, thus now adding an early d‐block metal to the small group of mid‐ and late‐d‐block metals (Mo, Fe, Ru, Os, Co) that are capable of executing catalytic production of NH3 by N2 reduction and protonolysis under homogeneous, abiological conditions. Under Ar, reduction o...

Reversible single-metal two-electron oxidative addition and reductive elimination are common fundamental reactions for transition metals that underpin major catalytic transformations. However, these reactions have never been observed together in the f-block because these metals exhibit irreversible one- or multi-electron oxidation or reduction reac...

We report the synthesis and characterisation of the compounds [An(TrenDMBS){Pn(SiMe3)2}] and [An(TrenTIPS){Pn(SiMe3)2}] [TrenDMBS = N(CH2CH2NSiMe2But)3, An = U, Pn = P, As, Sb, Bi; An = Th, Pn = P, As; TrenTIPS = N(CH2CH2NSiPri3)3, An = U, Pn = P, As, Sb; An = Th, Pn = P, As, Sb]. The U-Sb and Th-Sb moieties are unprecedented examples of any kind o...

We report the synthesis and characterisation of the compounds [An(TrenDMBS){Pn(SiMe3)2}] and [An(TrenTIPS){Pn(SiMe3)2}] [TrenDMBS = N(CH2CH2NSiMe2But)3, An = U, Pn = P, As, Sb, Bi; An = Th, Pn = P, As; TrenTIPS = N(CH2CH2NSiPri3)3, An = U, Pn = P, As, Sb; An = Th, Pn = P, As, Sb]. The U-Sb and Th-Sb moieties are unprecedented examples of any kind o...

The yttrium methanediide complex [Y(BIPM)(I)(THF)2] (BIPM = {C(PPh2NSiMe3)2}) was reacted with a series of potassium bis(silyl)amides to produce heteroleptic complexes by salt metathesis protocols. The methanediide complexes [Y(BIPM)(N″)(THF)] (1; N″ = {N(SiMe3)2}) and [Y(BIPM)(N**)(THF)] (2; N** = {N(SiMe2tBu)2}) were obtained for those relatively...

Neutral mesoionic carbenes (MICs) have emerged as an important class of carbene, however they are found only in the free form or ligated to a few d-block ions. Here, we report unprecedented f-block MIC complexes [M(N'')3{CN(Me)C(Me)N(Me)CH}] (M = U, Y, La, Nd; N'' = N(SiMe3)2). These complexes were prepared by a formal 1,4-proton migration reaction...

Neutral mesoionic carbenes (MICs) have emerged as an important class of carbene, however they are found only in the free form or ligated to a few d-block ions. Here, we report unprecedented f-block MIC complexes [M(N'')3{CN(Me)C(Me)N(Me)CH}] (M = U, Y, La, Nd; N'' = N(SiMe3)2). These complexes were prepared by a formal 1,4-proton migration reaction...

We report the synthesis and characterisation of a family of diuranium(IV)-μ-chalcogenide complexes including a detailed examination of their electronic structures and magnetic behaviours. Treatment of [U(TrenTIPS)] [1, TrenTIPS = N(CH2CH2NSiPri3)3] with Ph3PS, selenium or tellurium affords the diuranium(IV)-sulfide, selenide, and telluride complexe...

Reaction of [U(TrenTIPS)(PH2)] (1, TrenTIPS = N(CH2CH2NSiPri3)3) with C6H5CH2K and [U(TrenTIPS)(THF)][BPh4] (2) afforded a rare diuranium-parent-phosphinidiide complex [{U(TrenTIPS)}2(μ-PH)] (3). Treatment of 3 with C6H5CH2K and two equivalents of benzo-15-crown-5 ether (B15C5) gave the diuranium-μ-phosphido complex [{U(TrenTIPS)}2(μ-P)][K(B15C5)2]...

Reaction of [U(TrenTIPS)(PH2)] (1, TrenTIPS = N(CH2CH2NSiPri3)3) with C6H5CH2K and [U(TrenTIPS)(THF)][BPh4] (2) afforded a rare diuranium-parent-phosphinidiide complex [{U(TrenTIPS)}2(μ-PH)] (3). Treatment of 3 with C6H5CH2K and two equivalents of benzo-15-crown-5 ether (B15C5) gave the diuranium-μ-phosphido complex [{U(TrenTIPS)}2(μ-P)][K(B15C5)2]...

The reaction of [Zr(TrenDMBS)(Cl)] [Zr1, TrenDMBS = N(CH2CH2NSiMe2But)3] with NaPH2 gave the terminal parent phosphanide complex [Zr(TrenDMBS)(PH2)] [Zr2, Zr-P = 2.685(2) Å]. Treatment of Zr2 with one equivalent of KCH2C6H5 and two equivalents of benzo-15-crown-5 ether (B15C5) afforded an unprecedented example outside of matrix isolation of a struc...

The reaction of [Zr(TrenDMBS)(Cl)] [Zr1, TrenDMBS = N(CH2CH2NSiMe2But)3] with NaPH2 gave the terminal parent phosphanide complex [Zr(TrenDMBS)(PH2)] [Zr2, Zr-P = 2.685(2) Å]. Treatment of Zr2 with one equivalent of KCH2C6H5 and two equivalents of benzo-15-crown-5 ether (B15C5) afforded an unprecedented example outside of matrix isolation of a struc...

Despite a major expansion of uranium–ligand multiple bond chemistry in recent years, analogous complexes involving other actinides (An) remain scarce. For thorium, under ambient conditions only a few multiple bonds to carbon, nitrogen, phosphorus and chalcogenides are reported, and none to arsenic are known; indeed only two complexes with thorium–a...

Supplementary Figures, Supplementary Tables, Supplementary Methods and Supplementary References