Ebbe Nordlander

Lund University, Lund, Skåne, Sweden

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Publications (163)549.83 Total impact

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    Henrik Daver · Biswanath Das · Ebbe Nordlander · Fahmi Himo
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    ABSTRACT: The reaction mechanisms of phosphodiester hydrolysis and transesterification catalyzed by a dinuclear zinc complex mimicking the active site of zinc phosphotriesterase have been studied by means of density functional theory calculations. The substrates bis(2,4)-dinitrophenyl phosphate and 2-hydroxypropyl-p-nitrophenyl phosphate were considered as analogues of DNA and RNA, respectively. Different mechanistic proposals were evaluated, with the active catalyst carrying one or two hydroxide ions, which can act as either nucleophiles or Brønsted bases in the reactions.
    Full-text · Article · Jan 2016 · Inorganic Chemistry
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    ABSTRACT: The synthesis and characterization of twenty new pentamethylcyclopentadienyl-rhodium and iridium complexes containing N^N and N^O-chelating chloroquine analogue ligands are described. The in vitro antimalarial activity of the new ligands as well as the complexes was evaluated against the chloroquine sensitive (CQS) NF54 and the chloroquine resistant (CQR) Dd2 strains of Plasmodium falciparum. The antimalarial activity was found to be good to moderate; although all complexes are less active than Artesunate, some of the ligands and complexes showed better activity than chloroquine (CQ). In particular, rhodium complexes were found to be considerably more active than iridium complexes against the CQS NF54 strain. Salicylaldimine Schiff base ligands having electron withdrawing groups (F, Cl, Br, I and NO2) in para position of the salicyl moiety and their rhodium complexes showed good antiplasmodial activity against both the CQS-NF54 and the CQR-Dd2 strains. The crystal structures of (5-pentamethylcyclopentadienyl){N1-(7-chloroquinolin-4-yl)-N2-(pyridin-2-ylmethyl)ethane-1,2-diamine)}chlororhodium(III) chloride and (5-pentamethylcyclopentadienyl){(4-chloro-2-(((2-((7-chloroquinolin-4-yl)amino)ethyl)imino)methyl)phenolate)}chlororhodium(III) chloride are reported. The crystallization of the amino-pyridyl complex (5-pentamethylcyclopentadienyl){ (N1-(7-chloroquinolin-4-yl)-N2-(pyridin-2-ylmethyl)ethane-1,2-diamine)}chloroiridium(III) chloride in acetone resulted in the formation of the imino-pyridyl derivative (5-pentamethylcyclopentadienyl){ (N1-(7-chloroquinolin-4-yl)-N2-(pyridin-2-ylmethylene)ethane-1,2-diamine)}chloroiridium(III) chloride, the crystal structure of which is also reported.
    No preview · Article · Jan 2016 · Dalton Transactions
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    ABSTRACT: Eight new ruthenium and five new osmium p-cymene half-sandwich complexes have been synthesized, characterized and evaluated for antimalarial activity. All complexes contain ligands that are based on a 4-chloroquinoline framework related to the antimalarial drug chloroquine. Ligands are salicylaldimine derivatives, where = N-(2-((2-hydroxyphenyl)methylimino)ethyl)-7-chloroquinolin-4-amine, and contain non-hydrogen substituents in the 3-position of the salicylaldimine ring, viz. F, Cl, Br, I, NO2, OMe and (t)Bu for , respectively. Ligand is also a salicylaldimine-containing ligand with substitutions in both 3- and 5-positions of the salicylaldimine moiety, i.e. N-(2-((2-hydroxy-3,5-di-tert-butylphenyl)methyl-imino)ethyl)-7-chloroquinolin-4-amine, while is N-(2-((1-methyl-1H-imidazol-2-yl)methylamino)ethyl)-7-chloroquinolin-4-amine) The half sandwich metal complexes that have been investigated are [Ru(η(6)-cym)()Cl] (Ru--Ru-, cym = p-cymene), [Os(η(6)-cym)()Cl] (Os--Os-, Os-, and Os-), [M(η(6)-cym)()Cl2] (M = Ru, Ru-; M = Os, Os-) and [M(η(6)-cym)()Cl]Cl (M = Ru, Ru-; M = Os, Os-). In complexes Ru--Ru- and Ru-, Os--Os-, Os- and Os- and Os-, the ligands were found to coordinate as bidentate N,O- and N,N-chelates, while in complexes Ru- and Os-, monodentate coordination of the ligands through the quinoline nitrogen was established. The antimalarial activity of the new ligands and complexes was evaluated against chloroquine sensitive (NF54 and D10) and chloroquine resistant (Dd2) Plasmodium falciparum malaria parasite strains. Coordination of ruthenium and osmium arene moieties to the ligands resulted in lower antiplasmodial activities relative to the free ligands, but the resistance index is better for the ruthenium complexes compared to chloroquine. Overall, osmium complexes appeared to be less active than the corresponding ruthenium complexes.
    Full-text · Article · Oct 2015 · Dalton Transactions
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    ABSTRACT: Two new pentadentate {N5} donor ligands based on the N4Py (N4Py = N,N-bis(2-pyridylmethyl)-Nbis( 2-pyridyl)methylamine) framework have been synthesized, viz. [N-(1-methyl-2-benzimidazolyl)methyl-N-(2-pyridyl)- methyl-N-(bis-2-pyridyl methyl)amine] (L1) and [N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)-amine] (L2), where one or two pyridyl arms of N4Py have been replaced by corresponding (N-methyl)benzimidazolylcontaining arms. The complexes [FeII(CH3CN)(L)]2+ (L = L1 (1); L2 (2)) were synthesized, and reaction of these ferrous complexes with iodosylbenzene led to the formation of the ferryl complexes [FeIV(O)(L)]2+ (L = L1 (3); L2 (4)), which were characterized by UV−vis spectroscopy, high resolution mass spectrometry, and Mössbauer spectroscopy. Complexes 3 and 4 are relatively stable with half-lives at room temperature of 40 h (L = L1) and 2.5 h (L = L2). The redox potentials of 1 and 2, as well as the visible spectra of 3 and 4, indicate that the ligand field weakens as ligand pyridyl substituents are progressively substituted by (N-methyl)benzimidazolyl moieties. The reactivities of 3 and 4 in hydrogen-atom transfer (HAT) and oxygen-atom transfer (OAT) reactions show that both complexes exhibit enhanced reactivities when compared to the analogous N4Py complex ([FeIV(O)(N4Py)]2+), and that the normalized HAT rates increase by approximately 1 order of magnitude for each replacement of a pyridyl moiety; i.e., [FeIV(O)(L2)]2+ exhibits the highest rates. The second-order HAT rate constants can be directly related to the substrate C−H bond dissociation energies. Computational modeling of the HAT reactions indicates that the reaction proceeds via a high spin transition state.
    Full-text · Article · Jul 2015 · Inorganic Chemistry
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    ABSTRACT: A new μ-oxo diiron(III) complex of the lithium salt of the pyridine-based unsymmetrical ligand 3-[(3-{[bis(pyridin-2-ylmethyl)amino]methyl}-2-hydroxy-5-methylbenzyl)(pyridin-2-ylmethyl)amino]propanoate (LiDPCPMPP), [Fe2(μ-O)(LiDPCPMPP)2](ClO4)2, has been synthesized and characterized. The ability of the complex to catalyze oxidation of several alkanes and alkenes has been investigated by using CH3COOH/H2O2 (1:1) as an oxidative system. Moderate activity in cyclohexane oxidation (TOF = 33 h–1) and good activity in cyclohexene oxidation (TOF = 72 h–1) were detected. Partial retention of configuration (RC = 53 %) in cis- and trans-1,2-dimethylcyclohexane oxidation, moderate 3°/2° selectivity (4.1) in adamantane oxidation, and the observation of a relatively high kinetic isotope effect for cyclohexane oxidation (KIE = 3.27) suggest partial metal-based oxidation, probably in tandem with free-radical oxidation. Low-temperature UV/Vis spectroscopy and mass spectrometric studies in the rapid positive detection mode indicate the formation of a transient peroxido species, [Fe2(O)(O2)(LiDPCPMPP)2]2+, which might be an intermediate in the metal-based component of the oxidation process.
    Full-text · Article · Jul 2015 · European Journal of Inorganic Chemistry
  • Wesley R. Browne · Ebbe Nordlander
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    ABSTRACT: An overview of the papers in this cluster issue is presented. “Biological oxidation reactions utilising dioxygen, superoxide or hydrogen peroxide as oxidants are amongst the most ubiquitous of metal-catalysed reactions in biology. Over the last four years, the COST action CM1003 ‘Biological Oxidation Reactions – Mechanisms and Design of New Catalysts’ has brought together over 150 researchers from over 18 European countries to exchange ideas and collaborate on answering key questions facing the field.”
    No preview · Article · Jul 2015 · Berichte der deutschen chemischen Gesellschaft
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    ABSTRACT: The neutral dimanganese(II,III) complex [Mn2(BCPMP)(OAc)2] [1; BCPMP3– = 2,6-bis({(carboxymethyl)[(1-pyridyl)methyl]amino}methyl)-4-methylphenolato] has been synthesized and characterized. The complex contains two terminal carboxylate donors. Complex 1 was found to be an effective catalyst for the disproportionation of H2O2 with high catalytic rate and a turnover number of 7500, the highest turnover reported to date for a catalase mimic. The rates and TON were significantly higher than recorded for a dicationic dimanganese(II,III) counterpart ([Mn2(BPBP)(OAc)2]·(ClO4)2, 2; BPBP– = 2,6-bis{[bis(2-pyridylmethyl)amino]methyl}-4-butylphenolato), which lacks the terminal carboxylate donors, suggesting that introduction of a terminal carboxylate donor improves activity. A well-resolved 16-line pattern obtained upon addition of H2O2 to complex 1 suggests involvement of an MnIIIMnIV species in the catalytic cycle.
    No preview · Article · Jun 2015 · European Journal of Inorganic Chemistry
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    ABSTRACT: Reaction of Ru3(CO)12 with tris(2-thienyl)phosphine (PTh3) in CH2Cl2 at room temperature or in THF in the presence of a catalytic amount of Na[Ph2CO] furnishes the carbonyl substitution products Ru3(CO)11(PTh3) (1), Ru3(CO)10(PTh3)2 (2), and Ru3(CO)9(PTh3)3 (3). Heating 1 in toluene affords the cyclometalated cluster Ru3(CO)9{μ-Th2P(C4H2S)}(μ-H) (4) resulting from carbonyl loss and carbon–hydrogen bond activation, and both 4 and the substituted derivative Ru3(CO)8{μ-Th2P(C4H2S)}(PTh3)(μ-H) (5) resulted from the direct reaction of Ru3(CO)12 and PTh3 at 110 °C in toluene. Interestingly, thermolysis of 2 in benzene at 80 °C affords 5 together with phosphido-bridged Ru3(CO)7(μ-PTh2)2(μ3-η2-C4H2S) (6) resulting from both phosphorus–carbon and carbon–hydrogen bond activation of coordinated PTh3 ligand(s). Cluster 6 is the only product of the thermolysis of 2 in toluene. Heating cyclometalated 4 with Ru3(CO)12 in toluene at 110 °C yielded the tetranuclear phosphinidine cluster, Ru4(CO)9(μ-CO)2(μ4-η2-C4H2S)(μ4-PTh) (7), resulting from carbon–phosphorus bond scission, together with the pentaruthenium sulfide cluster, Ru5(CO)11(μ-PTh2)(μ4-η4-C4H3)(μ4-S) (8), in which sulfur is extruded from a thiophene ring. All the new compounds were characterized by elemental analysis, mass spectrometry, IR and NMR spectroscopy, and by single crystal X-ray diffraction analysis in case of clusters 4, 6, 7, and 8. Cluster 4 consists of a triangular ruthenium framework containing a μ3-Th2P(C4H2S) ligand, while 6 consists of a ruthenium triangle containing η2-μ3-thiophyne ligand and two edge-bridging PTh2 ligands. Cluster 7 exhibits a distorted square arrangement of ruthenium atoms that are capped on one side by a μ4-phosphinidene ligand and on the other by a 4e donating μ4-η2-C4H2S ligand. The structure of 8 represents a rare example of a pentaruthenium wing-tip bridged-butterfly skeleton capped by μ4-S and μ4-η4-C4H3 ligands. The compounds 4, 6, 7, and 8 have been examined by density functional theory (DFT), and the lowest energy structure computed coincides with the X-ray diffraction structure. The hemilabile nature of the activated thienyl ligand in 4 and 6 has also been computationally investigated.
    No preview · Article · Jun 2015 · Journal of Organometallic Chemistry
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    ABSTRACT: The reactivity of the σ,π–thienyl complex [Fe2(CO)6(μ-Th)(μ-PTh2)] (1) towards a range of phosphines has been studied. With PR3 (R = Ph, Th) carbonyl substitution affords [Fe2(CO)5(PR3)(μ-Th)(μ-PTh2)] (2a–b) as the major product, with smaller amounts of the thienyl–acyl complexes [Fe2(CO)5(PR3)(μ-OC-Th)(μ-PTh2)] (3a–b) resulting from a migratory carbonyl insertion into the thienyl ligand. With diphosphines, thienyl–acyl complexes are the major products in all cases. With dppm, [Fe2(CO)4(μ-dppm)(μ-OC-Th)(μ-PTh2)] (4) results in which the diphosphine bridges the iron–iron bond, while with other diphosphines the chelate complexes [Fe2(CO)4(κ2-diphosphine)(μ-OC-Th)(μ-PTh2)] (5–9) are isolated, as established through crystallographic studies on [Fe2(CO)4(κ2-dppe)(μ-OC-Th)(μ-PTh2)] (5) and [Fe2(CO)4(κ2-dppb)(μ-OC-Th)(μ-PTh2)] (9), both of which show that the diphosphine binds selectively to the oxygen-bound metal centre with phosphorus atoms lying trans to the metal–metal bond and μ-PTh2 bridge. With 1,2-bis(diphenylphosphino)benzene (dppb), [Fe2(CO)5{μ,κ2-C6H4PPh(C6H4)PPh2}(μ-PTh2)] (10) is isolated in low yields and results from cyclometalation of a phenyl ring and putative elimination of thiophene. In a separate experiment, it has been shown that heating 9 results in the slow formation of 10.
    No preview · Article · May 2015 · Inorganica Chimica Acta
  • M. Abdul Mottalib · Matti Haukka · Ebbe Nordlander
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    ABSTRACT: Reaction of the tricobalt carbyne cluster [Co3(μ3-CH)(CO)9] with chiral diphosphines of the Josiphos and Walphos families affords the new clusters [Co3(μ3-CH)(CO)7(P-P∗)] in good yield (P-P∗ = J004 (1), J005 (2), J007 (3), W001 (4), W003 (5)). The new alkylidyne tricobalt clusters, and the previously known [Co3(μ3-CH)(CO)7(μ-J003)], have been tested as catalysts/catalyst precursors for intermolecular Pauson-Khand cyclization, using norbornene and phenylacetylene as substrate. The diphosphine-substituted tricobalt carbonyl clusters proved to be viable catalyst/catalyst precursors that gave products in moderate to good yields, but the enantiomeric excesses were low. When the chiral diphosphine ligands were used as promoters/auxiliary ligands for the same Pauson-Khand reaction, using either [Co2(CO)8] or [Co4(CO)12] as catalyst precursors, both the overall yields and the selectivities with respect to cyclopentenone formation were significantly improved. The best results were obtained for ligands J007 and W001, with [Co4(CO)12] as pre-catalyst, where yields of 96%, and virtually 100% selectivity were obtained. However, the enantioselectivity of product formation was low or non-existent. The crystal structure of [Co3(μ3-CH)(CO)7(μ-J004)] is described. [J003 = [(R)-1-{(S)-2-(dicyclohexylphosphino)-ferrocenyl} ethyldicyclohexylphosphine], J004 = [(R)-1-{(S)-2-(dicyclohexylphosphino)- ferrocenyl} ethyldiphenylphosphine], J005 = [(R)-1-{(S)-2-(diphenylphosphino) ferrocenyl}ethyl-di-3,5-xylylphosphine], J007 = [(R)-1-{(S)-2-di-(4-methoxy-3,5-dimethylphenyl)phosphino)ferrocenyl} ethyldicyclohexylphosphine], W001 = [(R)-1-{(R)-2-(2’-diphenyl phosphinophenyl) ferrocenyl} ethyldi(bis-3,5-trifluoromethylphenyl)phosphine], W003 [(R)-1-{(R)-2-(2’-diphenylphosphino- phenyl)ferrocenyl}ethyldi(3,5-xylyl)phosphine]
    No preview · Article · Apr 2015 · Polyhedron
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    ABSTRACT: The synthesis of four molybdenum and tungsten complexes bearing tetradentate tripodal amino bisphenolate ligands with either hydroxyethylene (1a) or hydroxyglycolene (1b) substituents is reported. The molybdenum dioxo complexes [MoO2L] (L = 2a, 2b) and tungsten complexes [WO2L] (3a, 3b) were synthesized using [MoO2(acac)2] and [W(eg)3] (eg = 1,2-ethanediolato, ethylene glycolate), respectively, as precursors. All complexes were characterized by spectroscopic means as well as by single-crystal X-ray diffraction analyses. The latter reveal, in all cases, hexacoordinate complexes in which the hydrogen atom of the hydroxy group is involved in hydrogen bonding with one of the metal oxo groups. In the case of the glycol substituent, the ether oxygen atom is coordinated to the metal whereas the hydroxy group remains uncoordinated. The complexes were tested as catalysts in the epoxidation of cyclooctene under eco-friendly conditions, using an aqueous solution of H2O2 as the oxidant and dimethyl carbonate (DMC) as solvent or neat conditions, as substitutes for chlorinated solvents. Molybdenum complexes 2a and 2b showed good catalytic activity using H2O2 without added solvent, and tungsten complexes 3a and 3b showed very high activity in the epoxidation of cyclooctene using H2O2 and DMC as solvents.
    No preview · Article · Apr 2015 · Berichte der deutschen chemischen Gesellschaft
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    ABSTRACT: The mol-ecule of the title compound, C14H13N5O2, is approximately planar (r.m.s deviation for all non-H atoms = 0.093 Å), with the planes of the two pyridine rings inclined to one another by 5.51 (7)°. The oxime group is syn to the amide group, probably due to the formation of an intra-molecular N-H⋯N hydrogen bond that forms an S(6) ring motif. In the crystal, mol-ecules are linked by pairs of bifurcated O-H⋯(O,N) hydrogen bonds, forming inversion dimers. The latter are linked via C-H⋯O and C-H⋯N hydrogen bonds, forming sheets lying parallel to (502). The sheets are linked via π-π stacking inter-actions [inter-centroid distance = 3.7588 (9) Å], involving the pyridine rings of inversion-related mol-ecules, forming a three-dimensional structure.
    Full-text · Article · Dec 2014 · Acta Crystallographica Section E Structure Reports Online
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    ABSTRACT: Ten rhenium carbonyl complexes—[Re(H)(CO)3(1a)], [Re3(µ-H)3(CO)10(1a)], [Re2(CO)9(2a)], [Re2(CO)8(2a)], [Re2(CO)9(2b)], [{Re2(CO)9}2(2b)], [Re2(CO)8(2b)], [Re2(CO)8(1b)], [Re2(µ-H)2(CO)6(2b)] and [Re3(µ-H)3(CO)11(2b)]—containing different bidentate chiral phosphine ligands of the Josiphos (1a, 1b) and Walphos (2a, 2b) families have been synthesized and fully characterized (1a: (R)-1-{(S P)-2-[Bis[3,5-bis(trifluoromethyl)phenyl]phosphino]ferrocenyl}ethyldi(3,5-xylyl)phosphine, 1b: (R)-1-{(S P)-2-[Di(2-furyl)phosphino]ferrocenyl}ethyldi-tert-butylphosphine, 2a: (R)-1-{(R P)-2-[2-[Bis(4-methoxy-3,5-dimethylphenyl)phosphino]phenyl]ferrocenyl}ethylbis[3,5-bis(trifluoromethyl)phenyl]phosphine and 2b: (R)-1-{(R P)-2-[2-(Diphenylphosphino)phenyl]ferrocenyl}ethyldicyclohexylphosphine). The phosphine-substituted clusters were tested for hydrogenation of tiglic acid [trans-2-methyl-2-butenoic acid]. The catalytic reactions gave reasonable conversion rates (15–88 %) under relatively mild conditions but relatively moderate enantiomeric excesses (8–57 %) were observed. The crystal structures of [ReH(CO)3(1a)], [Re2(CO)9(2a)], [{Re2(CO)9}2(2b)] and [Re2(µ-H)2(CO)6(2b)] are presented.
    No preview · Article · Nov 2014 · Journal of Cluster Science
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    Ivan Castillo · Andrea C. Neira · Ebbe Nordlander · Erica Zeglio
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    ABSTRACT: Reaction of Cu2+ salts with the benzimidazole-N-methylated bis[(1-methyl-2-benzimidazolyl)ethyl]amine ligand 2BB results in either bi- or monometallic complexes. Spectroscopic and solid state characterization reveals either square pyramidal or trigonal bipyramidal coordination geometries around the cupric ions. In [{2BBCu(μ-F)}2](BF4)2, the dicopper structure is determined by the bridging nature of the fluoro ligands, which complement the T-shape arrangement of N3 donors provided by 2BB to define a square pyramidal (or capped distorted tetrahedral) coordination geometry. The monocopper complexes 2BBCuCl2 and [2BBCu(H2O)2](OTf)2 are characterized by a trigonal bipyramidal geometry both in solution and in the solid state. In all complexes, the T-shape N3 donor set of 2BB is analogous to the coordination environment of the copper ions provided by a ‘histidine brace’ and an additional histidine imidazole in the active site of polysaccharide monooxygenases.
    Full-text · Article · Oct 2014 · Inorganica Chimica Acta
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    Debbie C. Crans · Ebbe Nordlander
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    ABSTRACT: An overview of the papers in this cluster issue is presented. "It is more than 100 years ago that Alfred Werner developed the research that led to the birth of coordination chemistry as we know it today. The consequences of this seminal work continue to evolve, documenting that not only structural and electronic effects but also perhaps, most importantly, the application of coordination chemistry remain as timely and current now as it was back then." An overview of the papers in this cluster issue is presented. "It is more than 100 years ago that Alfred Werner developed the research that led to the birth of coordination chemistry as we know it today. The consequences of this seminal work continue to evolve, documenting that not only structural and electronic effects but also perhaps, most importantly, the application of coordination chemistry remain as timely and current now as it was back then."
    Full-text · Article · Sep 2014 · Berichte der deutschen chemischen Gesellschaft

  • No preview · Conference Paper · Aug 2014
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    ABSTRACT: The oxidation of sulfite to sulfate by two different models of the active site of sulfite oxidase has been studied. Both protonated and deprotonated substrates were tested. Geometries were optimized with density functional theory (TPSS/def2-SV(P)) and energies were calculated either with hybrid functionals and large basis sets (B3LYP/def2-TZVPD) including corrections for dispersion, solvation, and entropy, or with coupled-cluster theory (LCCSD(T0)) extrapolated toward a complete basis set. Three suggested reaction mechanisms have been compared and the results show that the lowest barriers are obtained for a mechanism where the substrate attacks a Mo-bound oxo ligand, directly forming a Mo-bound sulfate complex, which then dissociates into the products. Such a mechanism is more favorable than mechanisms involving a Mo-sulfite complex with the substrate coordinating either by the S or O atom. The activation energy is dominated by the Coulomb repulsion between the Mo complex and the substrate, which both have a negative charge of -1 or -2.
    Full-text · Article · Jun 2014 · JBIC Journal of Biological Inorganic Chemistry
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    ABSTRACT: Enantioselective hydrogenation of tiglic acid effected by diastereomers of the general formula [(μ-H)2Ru3(μ3-S)(CO)7(μ-P-P*)] (P-P* = chiral Walphos diphosphine ligand) strongly supports catalysis by intact Ru3 clusters. A catalytic mechanism involving Ru3 clusters has been established by DFT calculations.
    Full-text · Article · Jun 2014 · Chemical Communications
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    ABSTRACT: The new clusters [Ru-3(CO)(9)(mu-dppf){P(C4H3E)(3)}] (1, E = O; 2, E = S) have been prepared from the Me3NO-induced decarbonylation of [Ru-3(CO)(10)(mu-dppf)] in the presence of PFu(3) (E = O) and PTh3 (E = S), respectively. Upon thermolysis in benzene, the major products are the cyclometalated clusters [(mu-H) Ru-3(CO)(7)(mu-dppf){mu(3)-(C4H3E)(2)P(C4H2E)}] (3, E - O; 4, E - S). This thermolytic behavior is in marked contrast to that previously noted for the analogous bis(diphenylphosphino) methane (dppm) complexes [Ru-3(CO)(9)(mu-dppm){P(C4H3E)(3)}], in which both carbon-hydrogen and carbon-phosphorus bond activation yields furyne- and thiophyne-capped clusters. The crystal structures of 1, 3 and 4 are presented and reveal that phosphine migration has occurred during the transformation of 1,2 into 3,4, respectively. The possible relation of the observed reactivity to the relative flexibilities of the diphosphine ligands is discussed. Density functional calculations have been performed on the model cluster [Ru-3(CO)(9)(mu-Me-4-dppf){ P(C4H3O)(3)]}], and these data are discussed relative to the ground-state energy differences extant between the different isomeric forms of this cluster. The dynamic NMR behavior displayed by the metalated thienyl ring in cluster 4 has also been investigated by computational methods, and the free energy of activation for the "windshield wiper" motion of the activated thienyl moiety determined.
    Full-text · Article · Jun 2014 · Journal of Organometallic Chemistry
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    ABSTRACT: The heterodinuclear mixed-valence complex [FeMn(ICIMP)(OAc)2Cl] (1) {H2ICIMP = 2-(N-carboxylmethyl)-[N-(N-methylimidazolyl-2-methyl)aminomethyl]-[6-(N-isopropylmethyl)-[N-(N-methylimidazolyl-2-methyl)]aminomethyl-4-methylphenol], an unsymmetrical N4O2 donor ligand} has been synthesized and fully characterized by several spectroscopic techniques as well as by X-ray crystallography. The crystal structure of the complex reveals that both metal centers in 1 are six-coordinate with the chloride ion occupying the sixth coordination site of the MnII ion. The phenoxide moiety of the ICIMP ligand and both acetate ligands bridge the two metal ions of the complex. Mössbauer spectroscopy shows that the iron ion in 1 is high-spin FeIII. Two quasi-reversible redox reactions for the complex, attributed to the FeIIIMnII/FeIIMnII (at –0.67 V versus Fc/Fc+) and FeIIIMnII/FeIIIMnIII (at 0.84 V), were observed by means of cyclic voltammetry. Complex 1, with an FeIII–MnII distance of 3.58 Å, may serve as a model for the mixed-valence oxidation state of purple acid phosphatase from sweet potato. The capability of the complex to effect organophosphate hydrolysis (phosphatase activity) has been investigated at different pH levels (5.5–11) by using bis(2,4-dinitrophenyl)phosphate (BDNPP) as the substrate. Density functional theory calculations indicate that the substrate coordinates to the MnII ion. In the transition state, a hydroxide ion that bridges the two metal ions becomes terminally coordinated to the FeIII ion and acts as a nucleophile, attacking the phosphorus center of BDNPP with the concomitant dissociation of the leaving group.
    Full-text · Article · May 2014 · European Journal of Inorganic Chemistry

Publication Stats

2k Citations
549.83 Total Impact Points

Institutions

  • 1997-2016
    • Lund University
      • • Department of Physical Chemistry
      • • Center for Chemistry and Chemical Engineering
      • • Department of Organic Chemistry
      • • Department of Chemistry
      Lund, Skåne, Sweden
  • 2003-2010
    • Saint-Petersburg State Institute of Technology
      Sankt-Peterburg, St.-Petersburg, Russia
  • 1996-2008
    • University of Cambridge
      • Department of Chemistry
      Cambridge, England, United Kingdom
  • 2000-2007
    • University of Joensuu
      • Department of Chemistry
      Yoensu, Eastern Finland Province, Finland
  • 2005
    • University College London
      • Department of Chemistry
      Londinium, England, United Kingdom
  • 2002
    • Russian Academy of Sciences
      • Institute of the Problems of Chemical Physics
      Moskva, Moscow, Russia