Gareth R Owen

University of South Wales · Department of Chemistry and Pharmaceutical Science

This feature article examines some of the recent advances in the chemistry of Z-type transition metal-borane and X-type transition metal-boryl complexes. It focuses on the employment of these boron-based functionalities acting as stores and transfer agents for functional groups such as hydrides, alkyl groups and aryl groups which can either be abst...

The addition of H(2) across a transition metal-borane bond is reported for the first time providing a mechanism for recharging borane functional groups to borohydride.

The reactions of [Ir(κ3N,N,H-Tai)(COD)] and [Ir(κ3N,N,H-PhBai)(COD)] (where Tai = HB(azaindolyl)3 and PhBai = Ph(H)B(azaindolyl)2) with carbon monoxide result in the formation of Z-type iridium–borane complexes supported by 7-azaindole units. Analysis of the reaction mixtures involving the former complex revealed the formation of a single species i...

An unusual ruthenium(ii) complex frozen at an intermediate point of hydride transfer between boron and ruthenium centres is reported.

The catalytic hydrogenation of CO2 to formate was achieved using the previously reported dichloro(η⁶‐p‐cymene){diphenyl(3‐methyl‐2‐indolyl)phosphine}ruthenium (1) as a catalyst under mild conditions. In this complex, the phosphorus‐based ligand adopts a κ¹‐P coordination mode. The catalytic activity was achieved in the presence of DBU as a base pro...

A new hydroxo‐bridged ruthenium (II) complex [{Ru(η⁶‐p‐cymene)(ⁱPr2P−O)}2(μ‐OH)]Cl (2) has fortuitously been isolated from the reaction between the known ruthenium(II) complex [RuCl2(η⁶‐p‐cymene)(ⁱPr2P‐OH)] (1) in either CDCl3 or CHCl3 solutions in the presence of excess DBU (1,8‐diazabicyclo(5.4.0)undec‐7‐ene) at room temperature. Complex 2 is onl...

The synthesis, characterization and application of a new complex, [Ir(κ²‐P,N‐6‐DCyPon*)(COD)] (1), where 6‐DCyPon* is the anionic species, 6‐dicyclohexylphosphino‐2‐oxo‐pyridinide, is reported herein. Complex 1 was found to be an active catalyst in the hydrogenation of CO2 at room temperature. The ligand, 6‐DCyPon*, is derived via deprotonation of...

The coordination chemistry of scorpionate ligands based on borates containing the 7-azaindole heterocycle is relatively unexplored. Thus, there is a requirement to further understand their coordination chemistry. This article outlines the synthesis and characterization of a family of complexes containing anionic flexible scorpionate ligands of the...

Reaction of a new ligand 6-DiPPon (6-diisopropylphosphino-2-pyridone) with 0.5 equiv of [RuCl2(p-cymene)]2 resulted in the formation of a mixture of [RuCl2(p-cymene)(κ1-P-6-DiPPon)]2 (1) and [RuCl(p-cymene)(κ2-P,N-6-DiPPin)]Cl ([2]Cl) (where 6-DiPPin = 6-diisopropylphosphino-2-hydroxypyridine). The ratio between the two products can be controlled b...

In this work, the utilisation of aqueous ammonium carbonate, (NH 4 ) 2 CO 3 , has been investigated as a fuel for solid oxide cell technology for the first time. In its pure form, ammonium carbonate is a solid white power that can easily be stored. It is easily dissolved in water to create an ammonium-rich aqueous solution and can therefore potenti...

Production of coke required for steel manufacturing generates coke oven gas (COG) as by-product. Cleaning of COG yields an aqueous waste stream containing ammonia, water, phenol, carbon dioxide and trace components. Currently, this waste stream is disposed of by incineration. Due to the presence of carbon dioxide, a significant fraction of the ammo...

A portfolio of value-added chemicals, fuels and building block compounds can be envisioned from CO2 on an industrial scale. The high kinetic and thermodynamic stabilities of CO2, however, present a significant barrier to its utilisation as a C1 source. In this context, metal-ligand cooperation methodologies have emerged as one of the most dominant...

The preparation of oleophobic materials coated with a composite based on a multi-layer graphitic scaffolding is reported herein. A range of substrates were employed for this purpose including Kevlar, carbon...

The polymer, poly(diallyldimethylammonium chloride) (PDDA), is shown to undergo chemical change via a reduction mechanism during X-ray analysis. Examination of the N 1s spectrum of PDDA shows a time dependence on the degree of reduction, together with clear amplification of the extent of reduction through the charge compensation system and X-ray ir...

Ammonia (NH 3 ) is present as an impurity in coke oven gas (COG), which is a by-product of coke-making processes required for the manufacture of steel. Due to its highly corrosive and toxic nature, ammonia is removed from COG by water scrubbing processes generating a highly problematic aqueous waste stream containing ammonia (19 vol%), hydrogen sul...

Waste aqueous ammonia is produced in significant quantities as part of coke production processes required for steelmaking. In this work, the utilization of a simulated aqueous ammonia waste (ammonium hydroxide) was investigated using a commercially available anode-supported solid oxide cell. The electrical performance of the cell was characterized...

Waste aqueous ammonia is produced in significant quantities as part of coke production processes required for steelmaking. In this work, the utilization of a simulated aqueous ammonia waste (ammonium hydroxide) was investigated using a commercially available anode-supported solid oxide cell. The electrical performance of the cell was characterized...

Plasma-exfoliated multilayer graphitic material (MLG) consists of orderly aligned stacks which contain many partially oxidised graphitic layers. Slit pores are present between successive stacks and their presence allows for improved...

A new oleophobic composite material was synthesised utilising multi-layered graphitic (MLG) material as scaffolding is presented herein. The composite consisted of a polyelectrolyte/fluorosurfactant complex derived from polydiallyldimethylammonium chloride (PDDA) and...

A novel radical-based functionalisation strategy for the synthesis of functionalised commercially obtained plasma-synthesised multi-layer graphitic material (MLG) is presented herein. 4-(trifluoromethyl)phenyl boronic acid was utilised as a source of 4-(trifluoromethyl)phenyl radicals to covalently graft upon the graphitic surface of MLG. Such a me...

Syntheses and characterisation of group ten complexes containing the ligand diphenyl‐2‐(3‐methyl)indolylphosphine are presented herein. The complexes [trans‐PdCl2{PPh2(C9H8N)}2] (1), [cis‐PtCl2{PPh2(C9H8N)}2] (2), [trans‐Pd(CH3)Cl{PPh2(C9H8N)}2] (3) and [trans‐Pt(CH3)Cl{PPh2(C9H8N)}2] (4) have all been structurally characterized by X‐ray crystallog...

This chapter provides a highlight on some of the recent advances and structural features of neutral borane and anionic borohydride units which contain a single tethered supporting unit. The supporting units covered include one-, two- and three-atom bridges. It focuses on the synthesis and characterisation of complexes formed, looking in detail into...

The synthesis of the lithium salt of a bis-substituted borohydride anion containing a phenyl substituent and a 2-mercaptopyridyl unit (mp) is reported herein. This salt has been used as a pro-ligand for the synthesis of rhodium(I) complex, [Rh{κ3-H,H,S-H2B(Ph)(mp)}(NBD)] (1) (where NBD = 2,5-norbornadiene). The new boron-based ligand coordinates to...

Borohydride ligands featuring multiple pendant donor functionalities have been prevalent in the chemical literature for many decades now. More recent times has seen their development into new families of so-called soft scorpionates, for example, those featuring sulfur based donors. Despite all of these developments, those ligands containing just on...

The first successful synthesis and characterization of group ten complexes featuring flexible scorpionate ligands based on 7-azaindole heterocycles are reported herein. Addition of two equivalents of either K[HB(azaindolyl)3] or Li[HB(Me)(azaindolyl)2] to [M(μ-Cl)(η1,η2-COEOMe)]2 leads to the formation of two equivalents of the complexes [M{κ3-N,N,...

The synthesis and characterisation of a new anionic flexible scorpionate ligand, methyl(bis-7-azaindolyl)borohydride [MeBai]–is reported herein. The ligand was coordinated to a series of group nine transition metal centres forming the complexes, [Ir(MeBai)(COD)] (1), [Rh(MeBai)(COD)] (2), [Rh(MeBai)(CODMe)] (2-Me) and [Rh(MeBai)(NBD)] (3), where CO...

The synthesis and characterization of a series of platinum and palladium complexes containing a secondary borane Z-class ligand supported by 2-mercaptopyridine heterocycles is reported herein. Addition of 2 equiv of Na[H2B(mp)2] to [Pt(μ-Cl)(COEOMe)]2 (where COEOMe = 8-methoxycyclooct-4-en-1-ide) in the presence of 2 equiv of a tertiary phosphine (...

The sodium salt of a monosubstituted borohydride anion containing a 2-mercaptopyridyl unit (mp) is reported herein. This compound was coordinated to a rhodium(I) center providing the complex [Rh{κ3-H,H,S-H3B(mp)}(NBD)] (1) (where NBD = 2,5-norbornadiene) in which the boron-based ligand is coordinated to the rhodium center via the thione donor and t...

The synthesis of novel bis-thione ligand, bis(1-benzyl-imidazole-2-thione)methane, SSBn is reported for the first time. This ligand along with the previously reported bis(1-methyl-imidazole-2-thione)methane, SSMe has been utilised in the synthesis of a series of copper(I) halide complexes. The syntheses have been achieved by two methodologies. The...

The synthesis and investigation of ruthenium complexes containing the relatively unexplored ligand, diphenyl-2-(3-methyl)indolylphosphine, is presented herein. The complexes [RuCl2{PPh2(C9H8N)}3], [Ru2(μ-Cl)3(Cl)(MeCN){PPh2(C9H8N)}4] and [RuCl2(η 6-p-cymeme){PPh2(C9H8N)}] have been studied. Single crystals of the latter two complexes have been prep...

The addition of flexible scorpionate ligand, [](-) {i.e. HB(mt)2(mp), where mt = methyl-2-mercaptoimidazole and mp = 2-mercaptopyridine} to group eleven centres is reported for the first time. The coordination of this hybrid ligand to copper(i) and silver(i) centres in the presence of triphenylphosphine and trialkylphosphine co-ligands has been inv...

The N-heterocyclic carbene NHC/thione ligand precursors 1-[(3-R-2-thioxo-2H-imidazol-1-yl)methyl]-3-R-2H-imidazol-2-ium hexafluorophosphate, [HCSR]PF6 (R = methyl, benzyl) have been prepared and used in the synthesis of the complexes [Rh(CSR)(cod)][PF6] (R = methyl, benzyl; cod = 1,5-cyclooctadiene). The coordination and structural features of the...

The synthesis and characterization of palladium and platinum complexes containing the neutral ligand HB(mp)2 (where mp = 2-mercaptopyridyl) are presented. Addition of 2 equiv of Na[H2B(mp)2] to [M(Cl)(COEOMe)]2 (where M = Pt, Pd; COEOMe = 8-methoxycyclooct-4-en-1-ide) in the presence of 2 equiv of PPh3 leads to the formation of the metal–borane pin...

The mixed donor N-heterocyclic carbene (NHC)/thione ligand precursors [1-(3-R-2H-imidazol-1-yl-2-thione)methyl-3-R-2H-imidazol-2-ium]X, [HCSR]X (R = methyl, benzyl; X = Br, I), have been utilized to prepare a range of silver and palladium complexes. The coordination of CSR to silver(I) salts has been explored, providing dimeric complexes of the typ...

Ligand cooperation has become an important strategy in the development of new transition metal based transformations. By using this approach some remarkable new catalytic transformations have been achieved, all in the space of only a few years. The purpose of this tutorial review is to explore the potential utilisation of ligands containing borohyd...

The complexes [Ru(Tai)H(PPh3)2] (4) [Tai = HB(7-azaindolyl)3] and [Ru(ArBai)H(PPh3)2] [ArBai = Ar(H)B(7-azaindolyl)2; Ar = phenyl (5), mesityl (6) and 2-naphthyl (7)] have been prepared and fully characterised. Structural characterisation of complexes 4, 5 and 7 confirmed the expected κ3-NNH coordination mode of the azaindolyl-based ligands. In all...

The synthesis and characterization of the first platinum group metal complexes of the recently reported ligand [H2B(mp)2]− (where mp = 2-mercaptopyridyl) are presented herein. Addition of 2 equiv of Na[H2B(mp)2] to [MCl(COD)]2 (where M = Rh, Ir; COD = 1,5-cyclooctadiene) leads to the hydride migration products [Rh{κ3-SSB-BH(mp)2}(η3-C8H13)] and [Ir...

A new family of mixed-donor bidentate ligands containing both N-heterocyclic carbene (NHC) and thione functionalities is reported. The imidazolium salt precursors 1,1′-methylene(3-R-imidazol-2-ylidene)(3-R-2H-imidazole-2-thione) [CSRH] halide (where R = methyl, benzyl; halide = bromide, iodide) have been synthesized. Their coordination to copper(I)...

Two novel boron-based flexible scorpionate ligands based on 7-azaindole, Li[HB(azaindolyl)(2)(1-naphthyl)] and Li[HB(azaindolyl)(2)(mesityl)] {Li[(Naphth)Bai] and Li[(Mes)Bai] respectively}, have been prepared (mesityl = 2,4,6-trimethylphenyl). These salts have been isolated in two forms, either as dimeric structures which contain bridging hydride...

The complexes [Ru(Tai)Cl{=C(H)Ph}(PCy(3))] (4) and [Ru((Ph)Bai)Cl{=C(H)Ph}(PCy(3))] (5) [where Tai = HB(7-azaindolyl)(3) and (Ph)Bai = Ph(H)B(7-azaindolyl)(2)] have been prepared and structurally characterised. The borohydride unit is located in the coordination site trans to the chloride ligand in both complexes. The degree of interaction between...

A structural comparison of the coordination chemistry of the two linkage isomeric forms of bis(1-methylthioimidazolyl)methane, [H2C(N-mt)2] (LS), and [H2C(S-mt)2] (LN) to a number of zinc complexes has been carried out. The complexes ZnX2LS and ZnX2LN (where X=Cl, Br and I) have all been prepared in good to high yields and have been characterised b...

The ensemble of forces that stabilize protein structure and facilitate biological function are intimately linked with the ubiquitous aqueous environment of living systems. As a consequence, biomolecular activity is highly sensitive to the interplay of solvent-protein interactions, and deviation from the native conditions, for example by exposure to...

The synthesis and characterisation of a number of group nine complexes containing the recently reported ligand, diphenyl-2-(3-methyl)indolylphosphine, is presented herein. The complexes [RhCl(COD){PPh(2)(C(9)H(8)N)}] (1), [IrCl(COD){PPh(2)(C(9)H(8)N)}] (2), [RhCl(NBD){PPh(2)(C(9)H(8)N)}] (3) and [Rh(COD)(MeCN){PPh(2)(C(9)H(8)N)}]BF(4) (4) (where CO...

Reactions of trans,trans-(C6F5)(p-tol 3P)2Pt(CC)nPt(Pp-tol3) 2(C6F5) (PtCxPt; x = 2n) and the 1,3-diphosphine Ph2P(CH2)3PPh2 (2.5 equiv) give the tetraplatinum complexes trans, trans,trans,trans-(C 6F5)Pt(CC)nPt(C6F 5)(PPh2(CH2)3Ph2P) 2(C6F5)Pt(CC)nPt(C6F 5)(PPh2(CH2)3Ph2P) 2 ([Pt′CxPt′]2; x = 4/6/8, 39%/95%/81%). Crystal structures of [Pt′C8Pt′] 2...

AbstractThere has been great interest in metal–borane complexes following the discovery of metallaboratrane complexes in 1999. These complexes contain unusual Z-type (σ-acceptor) coordination of borane functional groups and have been shown to provide unexpected coordination geometries and properties for a transition metal in a particular oxidation...

The first structurally characterised zerovalent platinum complex to contain a tridentate pincer-type coordination mode (κ3-SBS) is presented, raising further questions concerning the geometries and trans influence of Z-type ligands.

A new boron-based hybrid scorpionate ligand based upon one 2-mercaptopyridine (mp) and two 1-methyl-imidazoyl-2-thione (mt) units, Na[HB(mt)2(mp)] has been prepared. This new ligand together with the recently reported ligand K[HB(mp)3] have been used to prepare analogues of the original metallaboratrane complex [Ru(CO)(PPh3){κ4-SSBS-B(mt)3}]. The e...

The syntheses and characterization of a number of palladium complexes containing imine and/or iminoacyl groups are reported. Our strategies toward the insertion of imines into palladium iminoacyl complexes are outlined. The imine complexes [Pd(Me)(L2){N(R′)═C(H)Ph}]X (where L2 = dppe, dppp, dppf; R′ = Ph, Me, Bz; and X = BF4 or OTf) were prepared a...

A new boron-based flexible scorpionate ligand based upon 7-azaindole, Li[Ph(H)B(azaindolyl)2] (Li[PhBai]), has been prepared. This ligand, together with the previously reported ligand K[HB(azaindolyl)3] (K[Tai]), have been used to prepare a range of monovalent group 9 transition-metal complexes. The complexes [M(COD){κ3N,N,H-Ph(H)B(azaindolyl)2}] (...

A new route to {Cu2(κ1-pyNH2)2(μ-OMe)2Cl2}n (pyNH2=2-aminopyridine) (3) is reported. Structural characterisation reveals the presence of methoxide and chloride bridging units within the complex which support close copper–copper bonding interactions resulting in interesting magnetic properties. The variable-temperature (4–300K) magnetic susceptibili...

A new family of flexible scorpionate ligands based on 2-mercaptopyridine is reported. The tris- and bis-substituted ligands, K[HB(mp)(3)] (1) and Na[H(2)B(mp)(2)] (2) (mp = 2-mercaptopyridine) have been prepared and fully characterised. The structural characterisation of 1 reveals an unprecedented mu(3)-kappa(3)-SS'H-eta(1)eta(1)eta(2)-kappa(2)-S''...

The reaction of Ir(COD)(Tai) [where Tai = {HB(7-azaindoyl)(3)}(-)] with carbon monoxide results, via a sequence of hydride migration and insertion steps, in the formation of the first complexes to contain a metal-to-boron dative interaction supported by 7-azaindole units.

Rhodium and iridium complexes of flexible scorpionate ligands based on azaindole were synthesised in good yields. The complexes were characterised in solution and in the solid state. Structural characterisation revealed a B-H-metal interaction, which is retained in solution. Given the greater flexibility of the ligand and potential cooperative effe...

Sequential reactions of trans-(C6F5)(p-tol3P)2Pt(C[triple chemical bond]C)3SiEt3 (PtC6SiEt3) with nBu4N+ F(-) (THF/methanol), PtCl, KPF6/tBuOK, and CuCl give trans,trans-[(C6F5){(p-tol3P)2}Pt(C[triple chemical bond]C)3Pt{(Pp-tol3)2}(C6F5)] (PtC6Pt) in 95 % yield on multigram scales. Reactions of PtC6Pt and Ar2P(CH2)mPAr2 afford substitution product...

The reaction of [Ru(CHCH2)Cl(CS)(PPh3)2] with Na[HB(mt)3] (mt = methimazolyl) provides the ruthenaboratrane [Ru(CS)(PPh3){B(mt)3}]. The reaction of [Ru(CO)(PPh3){B(mt)3}] with CO to provide [Ru(CO)2{B(mt)3}] is reversible, while the phosphine-free ruthenaboratranes [Ru(CO)(CNR){B(mt)3}] (R = tBu, C6H3Me2-2,6, C6H2Me3-2,4,6) form irreversibly upon a...

Reactions of trans,trans-(C6F5)(p-tol3P)2Pt(CC)4Pt(Pp-tol3)2(C6F5) and diphosphines Ar2P(CH2)mPAr2 yield trans,trans-(C6F5)(Ar2P(CH2)mPAr2)Pt(CC)4Pt(Ar2P(CH2)mPAr2)(C6F5), in which the platinum atoms are spanned via an sp and two sp3 carbon chains (Ar/m = 3, Ph/14, 87%; 4, p-tol/14, 91%; 5, p-C6H4-t-Bu/14, 77%; 7, Ph/10, 80%; 8, Ph/11, 80%; 9, Ph/1...

In the title compound, [Na(C5H5NO)4]BF4, each Na+ ion, lying on an inversion centre, is octa­hedrally coordinated by four bridging and two terminal pyridone ligands, creating a cationic coordination polymer chain with tetra­fluoro­borate anions occupying the spaces between the chains.

In the title compound, [Na(C5H5NO)4]BF4, each Na+ ion, lying on an inversion centre, is octa­hedrally coordinated by four bridging and two terminal pyridone ligands, creating a cationic coordination polymer chain with tetra­fluoro­borate anions occupying the spaces between the chains.

The title compound, [Pd(CH3)Cl(C5H5N)2], has been synthesized by the reaction of [PdMeCl(COD)] (COD is 1,5-cyclo­octa­diene) with pyridine in dichloro­methane; it is square-planar. The crystal structure features dipole–dipole and π stacking interactions.

The synthesis of the new bidentate N–N ligand 1-(2-(1-(pyridin-2-yl)ethylideneamino)ethyl)-3-ethylurea (PyUr) with a urea substituent attached to the imine nitrogen is reported. This ligand has been used to form palladium complexes and study the potential influence of the urea group (as a hydrogen bonding unit and a hemilabile ligand) in the insert...

When trans,trans-(C6F5)(p-tol3P)2Pt(CC)3Pt(P-p-tol3)2(C6F5) and Ar2P(CH2)mPAr2 (m/Ar = 8/p-tol, 10/Ph, 11/Ph, 12/Ph, 14/p-tol) are reacted, p-tol3P is displaced to give products in which the diphosphines span the platinum end groups. One crystal structure (m = 14) shows a double-helical conformation in which the sp3 carbon chains twist around the s...

Reactions of trans, trans-(C6F5)(p-tol(3)P)(2)Pt-(Cequivalent toC)(n)Pt(P-p-tol(3))(2)(C6F5) (n = 3,4) and Ph2P(CH2)(3)PPH2 (2,5 equiv) give the tetraplatinum complexes trans, trans, trans, trans-(C6F5)Pt(Cequivalent toC)(n)Pt(C6F5)(PPH2(CH2)(3)Ph2P)(2)-(C6F5)Pt(Cequivalent toC)(n)Pt(C6F5)(PPH2(CH2)(3)Ph2P)(2) (95-81%), in which two sp carbon chain...

The reactions of [RuHCl(CO)(PPh3)3] or [RuH(NCMe)2(CO)(PPh3)2]ClO4 with Na[HB(mt)3] (mt = methimazolyl) provide the structurally characterized complex [RuH(CO)(PPh3){κ3-H,S,S‘ ‘-HB(mt)3}], which hydrogenates ethynylbenzene to styrene with formation of the ruthenaboratrane [Ru(CO)(PPh3){B(mt)3}](Ru→B).

The reactions of palladium−iminoacyl complexes with isocyanates (RNCO) and isothiocyanates (RNCS) have been investigated. The reaction of Pd{C(Me)NXy}(Cl)(P−P) (P−P = dppe, 1; dppp, 2) with RNCE (E = O, S) in the presence of AgBF4 yields the novel compounds (E = O and R = Et, 3; Ph, 4; E = S and R = Me, 5; Ph, 6); the formation of these complexes r...

Removal of the chloride atom from Pd{C(NXy)CH3}(Cl)(But2bipy) initiates a series of reactions that lead to the formation of the novel dipalladium complex [Pd(But2bipy){η2-[Pd(But2bipy){N(Xy)C(CH3)C(CH3)NXy}]}][BF4]2. In this process, two imidoyl groups undergo a C−C coupling reaction generating a bis-imino ligand that coordinates to two palladium c...

We have reported previously that the reaction of [Pd2(dba)3] (dba = dibenzylideneacetone) with PBz3 in the presence of SO2 yields [Pd2(μ-SO2)(μ-dba)(PBz3)2] (1) and [Pd3(μ-SO2)3(PBz3)3] (2) (which can be prepared selectively by varying the concentration of SO2). Here the reactions of 1 and 2 with PPh2py (diphenylpyridine phosphine) to yield [Pd2(μ-...

A systematic study of the insertion reactions between (P−P)Pd(Me)Cl (where P−P = dppe, dppp, dppf) and CNR (where R = 2,6-dimethylphenyl, tert-butyl) is presented. The results have demonstrated that the insertion of CNR into the Pd−Me bond is highly dependent on the nature of the chelating phosphine. For the more strained complex formed with dppe,...

An unprecedented intramolecular B−H activation of a hydrotris(2-sulfanyl-1-methylimidazolyl)borate ligand coordinated to ruthenium has provided the first example of metallaboratranes. The remarkable ease with which the ruthenaboratrane 1 forms relative to the case with a hydrotris(pyrazolyl)borate ligand is a consequence of the lability of the chel...

Eine ungewöhnliche intramolekulare B-H-Aktivierung eines Hydrotris(2-sulfanyl-1-methylimidazolyl)boratliganden, der ein Rutheniumzentrum koordiniert, führte zu den ersten Metallaboratranen. Die bemerkenswerte Leichtigkeit der Bildung des Ruthenaboratrans 1 gegenüber der Bildung des entsprechenden Komplexes mit dem Hydrotris(pyrazolyl)boratliganden...