Gareth R Owen

Gareth R Owen
University of South Wales · Department of Chemistry and Pharmaceutical Science

Ph.D. Imperial College London

About

63
Publications
6,900
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1,849
Citations
Additional affiliations
November 2013 - present
University of South Wales
Position
  • Lecturer
October 2013 - present
University of Bristol
April 2003 - September 2004
Friedrich-Alexander Universität Erlangen-Nürnberg

Publications

Publications (63)
Article
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...
Article
Full-text available
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.
Article
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...
Article
Full-text available
An unusual ruthenium(ii) complex frozen at an intermediate point of hydride transfer between boron and ruthenium centres is reported.
Article
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...
Conference Paper
Full-text available
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...
Article
Full-text available
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...
Article
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...
Article
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...
Chapter
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...
Article
Full-text available
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...
Article
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...
Article
Full-text available
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...
Article
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,...
Article
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...
Article
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 (...
Article
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...
Article
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...
Article
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...
Article
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...
Article
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...
Article
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...
Article
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...
Article
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...
Article
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...
Article
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...
Article
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)...
Article
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...
Article
Full-text available
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...
Article
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...
Article
Full-text available
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...
Article
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...
Article
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...
Article
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...
Article
Full-text available
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.
Article
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...
Article
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...
Article
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}] (...
Article
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...
Article
Full-text available
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''...
Article
Full-text available
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.
Article
Full-text available
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...
Article
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...
Article
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...
Article
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...
Article
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.
Article
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.
Article
Full-text available
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.
Article
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...
Article
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...
Article
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...
Article
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).
Article
Full-text available
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...
Article
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...
Article
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-...
Article
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,...
Article
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...
Article
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...

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