Results
- Showing results for:
- Reset all filters
Search results
-
Journal articleMartínez-Ferraté O, Britovsek GJP, Claver C, et al., 2015,
C–H benzylic oxidation promoted by dinuclear iron DBDOC iminopyridine complexes
, Inorganica Chimica Acta, ISSN: 0020-1693 -
Journal articlePetersen AR, Taylor RA, Vicente-Hernandez I, et al., 2014,
Oxygen insertion into metal carbon bonds: formation of methylperoxo Pd(II) and Pt(II) complexes via photogenerated dinuclear intermediates
, Journal of the American Chemical Society, Vol: 136, Pages: 14089-14099, ISSN: 1520-5126Platinum(II) and palladium(II) complexes [M(CH₃)(L)]SbF₆ with substituted terpyridine ligands L undergo light-driven oxygen insertion reactions into metal methyl bonds resulting in methylperoxo complexes [M(OOCH₃)(L)]SbF₆. The oxygen insertion reactions occur readily for complexes with methyl ligands that are activated due to steric interaction with substituents (NH₂, NHMe or CH₃) at the 6,6″-positions on the terpyridine ligand. All complexes exhibit attractive intermolecular π···π or M···M interactions in the solid state and in solution, which lead to excited triplet dinuclear M–M complexes upon irradiation. A mechanism is proposed whereby a dinuclear intermediate is generated upon irradiation that has a weakened M–C bond in the excited state, resulting in the observed oxygen insertion reactions.
-
Journal articleCecchini MP, Turek VA, Demetriadou A, et al., 2014,
Heavy Metal Sensing Using Self-Assembled Nanoparticles at a Liquid–Liquid Interface
, Advanced Optical Materials -
Journal articlePetersen AR, Taylor RA, Vicente-Hernandez I, et al., 2014,
Light-Driven Methyl Exchange Reactions in Square-Planar Palladium(II) and Platinum(II) Complexes
, ORGANOMETALLICS, Vol: 33, Pages: 1453-1461, ISSN: 0276-7333- Author Web Link
- Cite
- Citations: 10
-
Journal articleMcGuinness DS, Chan B, Britovsek GJP, et al., 2014,
Ethylene Trimerisation with Cr-PNP Catalysts: A Theoretical Benchmarking Study and Assessment of Catalyst Oxidation State
, AUSTRALIAN JOURNAL OF CHEMISTRY, Vol: 67, Pages: 1481-1490, ISSN: 0004-9425- Author Web Link
- Cite
- Citations: 28
-
Journal articleGrau M, Rigodanza F, White AJP, et al., 2014,
Ligand tuning of single-site manganese-based catalytic antioxidants with dual superoxide dismutase and catalase activity
, CHEMICAL COMMUNICATIONS, Vol: 50, Pages: 4607-4609, ISSN: 1359-7345- Author Web Link
- Cite
- Citations: 31
-
Journal articleGrau M, Kyriacou A, Martinez FC, et al., 2014,
Unraveling the origins of catalyst degradation in non-heme iron-based alkane oxidation
, DALTON TRANSACTIONS, Vol: 43, Pages: 17108-17119, ISSN: 1477-9226- Author Web Link
- Cite
- Citations: 45
-
Journal articleGrau M, England J, de Rosales RTM, et al., 2013,
Coordination Equilibria Between Seven- and Five-coordinate Iron(II) Complexes
, INORGANIC CHEMISTRY, Vol: 52, Pages: 11867-11874, ISSN: 0020-1669- Author Web Link
- Cite
- Citations: 19
-
Journal articleWhiteoak CJ, Nobbs JD, Kiryushchenkov E, et al., 2013,
Tri(pyridylmethyl)phosphine: The Elusive Congener of TPA Shows Surprisingly Different Coordination Behavior
, INORGANIC CHEMISTRY, Vol: 52, Pages: 7000-7009, ISSN: 0020-1669- Author Web Link
- Cite
- Citations: 26
-
Journal articleCoskun T, Conifer CM, Stevenson LC, et al., 2013,
Carbodeoxygenation of Biomass: The Carbonylation of Glycerol and Higher Polyols to Monocarboxylic Acids
, CHEMISTRY-A EUROPEAN JOURNAL, Vol: 19, Pages: 6840-6844, ISSN: 0947-6539- Author Web Link
- Cite
- Citations: 16
-
Journal articleWong E, Jeck J, Grau M, et al., 2013,
A strong-field pentadentate ligand in iron-based alkane oxidation catalysis and implications for iron(IV) oxo intermediates
, CATALYSIS SCIENCE & TECHNOLOGY, Vol: 3, Pages: 1116-1122, ISSN: 2044-4753- Author Web Link
- Cite
- Citations: 16
-
Journal articleKarpiniec SS, McGuinness DS, Britovsek GJP, et al., 2012,
Acetylene Cyclotrimerization with an Iron(II) Bis(imino)pyridine Catalyst
, ORGANOMETALLICS, Vol: 31, Pages: 3439-3442, ISSN: 0276-7333- Author Web Link
- Cite
- Citations: 35
-
Journal articleNobbs JD, Tomov AK, Cariou R, et al., 2012,
Thio-Pybox and Thio-Phebox complexes of chromium, iron, cobalt and nickel and their application in ethylene and butadiene polymerisation catalysis.
, Dalton Trans., Vol: 41, Pages: 5949-5964, ISSN: 1477-9226Seven bis(thiazolinyl)- and bis(thiazolyl)pyridine Thio-Pybox ligands and their metal complexes of Cr(III), Fe(II), Co(II) and Ni(II) were prepd., as well as a Ni(II) complex contg. a monoanionic bis(thiazolinyl)phenyl Thio-Phebox ligand. These new metal complexes were characterized and used as catalysts, in combination with the co-catalyst MAO, for the polymn. of ethylene and for the polymn. of butadiene. In the case of ethylene polymn., the Thio-Pybox and Thio-Phebox metal complexes showed relatively low polymn. activities, much lower compared to the related bis(imino)pyridine complexes of the same metals. In the polymn. of butadiene, several Thio-Pybox Co(II) complexes show very high activities, significantly higher than the other metal complexes with the same ligand. It is the metal, rather than the ligand, that appears to have the most profound effect on the catalytic activity in butadiene polymn., unlike in the polymn. of ethylene, where bis(imino)pyridine ligands provide highly active catalysts for a range of 1st row transition metals. The mol. structures of one ligand and eight complexes were detd. by x-ray crystallog. [on SciFinder(R)]
-
Journal articleSmit TM, Tomov AK, Britovsek GJP, et al., 2012,
The effect of imine-carbon substituents in bis(imino)pyridine-based ethylene polymerisation catalysts across the transition series.
, Catal. Sci. Technol., Vol: 2, Pages: 643-655, ISSN: 2044-4753The synthesis, characterization and ethylene polymn. behavior of a series of first row transition metal complexes of the general formula LMXn (M = Fe, Co, Mn, n = 2, X = Cl; M = V, Cr, Ti, n = 3, X = Cl; M = Ni, n = 2, X = Br) with bis(imino)pyridine ligands L are reported, whereby the ligands contain heteroatom substituents DRm at the imine carbon (D = O, S, m = 1, R = Me, Ph, 2,6-Me2C6H3 or D = N, m = 2, R = Me, Ph). Only the O- and S-substituted complexes show catalytic activity for the polymn. of ethylene, upon activation with methylaluminoxane (MAO). The Mn- and Ni-based catalysts were found to be inactive under these conditions. The S-substituted complexes are generally more active than the O-substituted complexes and the catalytic activities increase with the size of the substituents. Iron-, vanadium- and chromium-based catalysts give highly active catalyst systems, which in some cases are more active than the well-known ketimine catalysts. All catalysts produce highly linear polyethylene with mol. wts. affected by M, D and R. O-substituted catalyst systems are generally less active and produce lower mol. wt. polyethylene compared to S-substituted systems. [on SciFinder(R)]
-
Journal articleBritovsek GJP, 2012,
Homogeneous Catalysts Activity-Stability-Deactivation. By Piet W. N. M. van Leeuwen and John C. Chadwick.
, Angew. Chem., Int. Ed., Vol: 51, ISSN: 1433-7851 -
Conference paperBritovsek G, Taylor R, Petersen A, 2011,
Towards catalytic alkane oxidation via O<sub>2</sub> insertion into platinum methyl bonds
, 242nd National Meeting of the American-Chemical-Society (ACS), Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727 -
Conference paperElias S, Quinson J, Britovsek GJP, et al., 2011,
Electrocatalytic CO<sub>2</sub> reduction using modified electrodes
, 242nd National Meeting of the American-Chemical-Society (ACS), Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727 -
Journal articleConifer CM, Taylor RA, Law DJ, et al., 2011,
First metal complexes of 6,6'-dihydroxy-2,2'-bipyridine: from molecular wires to applications in carbonylation catalysis.
, Dalton Trans, Vol: 40, Pages: 1031-1033The first square planar rhodium(I) complexes containing the 6,6'-dihydroxy-2,2'-bipyridine ligand have been prepared. The complexes form molecular wires in the solid state and are active catalysts for the carbonylation of methyl acetate.
-
Journal articleKarpiniec SS, McGuinness DS, Britovsek GJP, et al., 2011,
Evaluation of mid-to-late transition metal imine catalysts for acetylene oligomerisation: A high activity bis(imino)pyridine iron(II) catalyst
, Catalysis Today, Vol: 178, Pages: 64 - 71-64 - 71, ISSN: 0920-5861 -
Conference paperTomov AK, Nobbs JD, Britovsek GJ, et al., 2011,
Alternating α-olefin distributions in chromium-catalysed ethylene oligomerisation.
, Publisher: American Chemical Society, Pages: INOR-529The last two decades have witnessed tremendous advances in catalyst development for the selective oligomerisation of ethylene.1 The Cossee-type chain growth mechanism results, in the absence of chain termination reactions, in a Poisson distribution of products (e.g. Alfen process). A combination of chain propagation and chain termination, for example β-H transfer, results in a Schulz-Flory distribution of α-olefins, (e.g. Shell Higher Olefin Process). An alternative chain growth mechanism based on the formation of metallacycles has enabled the selective trimerisation and tetramerisation of ethylene or the formation of higher oligomers. We have previously communicated an exceptionally active chromium-based catalyst supported by a tridentate bis(benzimidazolyl)amine ligand that affords a previously unobserved alternating α-olefin distribution, as shown below.2 Further studies on this remarkable catalyst system as well as mechanistic implications for olefin polymn. catalysis will be presented. Refernces 1)McGuinness, D. Rev., 2011, 111 ,2321. 2)Tomov, A.K.; Chirinos, J.J.; Long, R.; Gibson, V.C.; Elsegood. 2006, 128, 7704. [on SciFinder(R)]
-
Journal articleConifer CM, Law DJ, Sunley GJ, et al., 2011,
Lewis Acids and Lewis Acid-Functionalized Ligands in Rhodium-Catalyzed Methyl Acetate Carbonylation
, Organometallics, Vol: 30, Pages: 4060-4066-4060-4066 -
Journal articleKarpiniec SS, McGuinness DS, Britovsek GJP, et al., 2011,
High activity acetylene polymerisation with a bis(imino) pyridine iron(II) catalyst
, CHEMICAL COMMUNICATIONS, Vol: 47, Pages: 6945-6947, ISSN: 1359-7345- Author Web Link
- Cite
- Citations: 7
-
Journal articleConifer CM, Taylor RA, Law DJ, et al., 2011,
First metal complexes of 6,6′-dihydroxy-2,2′-bipyridine: from molecular wires to applications in carbonylation catalysis
, DALTON TRANSACTIONS, Vol: 40, Pages: 1031-1033, ISSN: 1477-9226- Author Web Link
- Cite
- Citations: 30
-
Journal articleConifer CM, Law DJ, Sunley GJ, et al., 2011,
Dicarbonylrhodium(I) Complexes of Bipyridine Ligands with Proximate H-Bonding Substituents and Their Application in Methyl Acetate Carbonylation
, European Journal of Inorganic Chemistry, Vol: 2011, Pages: 3511-3522, ISSN: 1099-0682 -
Journal articleWhiteoak CJ, Torres Martin de Rosales R, White AJP, et al., 2010,
Iron(II) complexes with tetradentate bis(aminophenolate) ligands: synthesis and characterization, solution behavior, and reactivity with O(2).
, Inorg Chem, Vol: 49, Pages: 11106-11117Tetradentate bis(aminophenolate) ligands H(2)salan(X) and H(2)bapen(X) (where X refers to the para-phenolate substituent = H, Me, F, Cl) react with [Fe{N(SiMe(3))(2)}(2)] to form iron(II) complexes, which in the presence of suitable donor ligands L (L = pyridine or THF) can be isolated as the complexes [Fe(salan(X))(L)(2)] and [Fe(bapen(X))(L)(2)]. In the absence of donor ligands, either mononuclear complexes, for example, [Fe(salan(tBu,tBu))], or dinuclear complexes of the type [Fe(salan(X))](2) are obtained. The dynamic coordination behavior in solution of the complexes [Fe(salan(F))(L)(2)] and [Fe(bapen(F))(L)(2)] has been investigated by VT (1)H and (19)F NMR spectroscopy, which has revealed equilibria between isomers with different ligand coordination topologies cis-α, cis-β and trans. Exposure of the iron(II) salan(X) complexes to O(2) results in the formation of oxo-bridged iron(III) complexes of the type [{Fe(salan(X))}(2)(μ-O)] or [{Fe(salan(X))(L)}(2)(μ-O)]. The lack of catalytic activity of the iron(II) salan and bapen complexes in the oxidation of cyclohexane with H(2)O(2) as the oxidant is attributed to the rapid formation of stable and catalytically inactive oxo-bridged iron(III) complexes.
-
Journal articleWhiteoak CJ, de Rosales RTM, White AJP, et al., 2010,
Iron(II) Complexes with Tetradentate Bis(aminophenolate) Ligands: Synthesis and Characterization, Solution Behavior, and Reactivity with O<sub>2</sub>
, INORGANIC CHEMISTRY, Vol: 49, Pages: 11106-11117, ISSN: 0020-1669- Author Web Link
- Cite
- Citations: 34
-
Journal articleCariou R, Chirinos JJ, Gibson VC, et al., 2010,
The effect of the central donor in bis(benzimidazole)-based cobalt catalysts for the selective cis-1,4-polymerization of butadiene.
, Dalton Trans., Vol: 39, Pages: 9039-9045, ISSN: 1477-9226A series of bis(benzimidazole)-based cobalt(ii) dichloride complexes contg. a range of different central donors has been synthesized and characterized. The nature of the central donor affects the binding of the ligand to the cobalt center and dets. the coordination geometry of the metal complexes. All complexes have been shown to catalyze the polymn. of butadiene, in combination with MAO as the co-catalyst, to give cis-1,4-polybutadiene with high selectivity. The nature of the central donor has a marked influence on the polymn. activity of the catalysts, but does not affect the polymer microstructure. The addn. of PPh3 generally increases the polymn. activity of these cobalt catalysts and results in predominantly (60-70%) 1,2-vinyl-polybutadiene. [on SciFinder(R)]
-
Journal articleLyakin OY, Bryliakov KP, Britovsek GJP, et al., 2009,
EPR Spectroscopic Trapping of the Active Species of Nonheme Iron-Catalyzed Oxidation
, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, Vol: 131, Pages: 10798-+, ISSN: 0002-7863- Author Web Link
- Cite
- Citations: 127
-
Journal articleEngland J, Gondhia R, Bigorra-Lopez L, et al., 2009,
Towards robust alkane oxidation catalysts: electronic variations in non-heme iron(II) complexes and their effect in catalytic alkane oxidation
, DALTON TRANSACTIONS, Pages: 5319-5334, ISSN: 1477-9226- Author Web Link
- Cite
- Citations: 87
-
Journal articleWhiteoak CJ, Britovsek GJP, Gibson VC, et al., 2009,
Electronic effects in oxo transfer reactions catalysed by salan molybdenum(VI) <i>cis</i>-dioxo complexes
, DALTON TRANSACTIONS, Pages: 2337-2344, ISSN: 1477-9226- Author Web Link
- Cite
- Citations: 54
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.
Contact
Prof. Dr. George Britovsek FRSC
Director MRes Catalysis & Engineering
Tel: +44 (0)20 7594 5863
Email: g.britovsek@imperial.ac.uk
Department of Chemistry
Imperial College London
Molecular Sciences Research Hub
White City Campus
80 Wood Lane
London W12 0BZ
United Kingdom