Change search
Refine search result
1 - 18 of 18
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Algarra, Andres G.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Computational Insights into the Isomerism of Hexacoordinate Metal-Sarcophagine Complexes: The Relationship between Structure and Stability2015In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 3, p. 503-511Article in journal (Refereed)
    Abstract [en]

    The hexacoordinate complexes that the macrobicyclic ligands {(NH3)(2)sar)(2+) and {NMe3)(2)sar}(2+) (sar = 3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane) form with transition metals such as Co-III, Co-II and Cu-II can adopt several isomeric structures. In this article, we have firstly employed DFT methods lo compute the relative stability of their Delta-ob(3), Delta-ob(2)lel, Delta-lel(2)ob and Delta-lel(3) isomers, as well as the activation barriers for their interconversion. In agreement with the experimental data, the results show that, in general, the different isomers of the Co-III and Co-II complexes present similar free energies, whereas the Cu-II complexes show a strong tendency towards the lel(3) form. In addition, the interplay between the structure and stability of these species has been studied by combining shape maps with a distortion/interaction energy analysis. In contrast to the geometries close to the ideal octahedron that all the studied Co complexes present, the le)3 structures of [Cu{(NH3)(2)sar}](4+) and [Cu{(NMe3)(2)sar](4+) are better described. as trigonal prisms. In such structures the ligand adopts a conformation significantly more stable than in the other isomers, and this drives the formation of lel(3)-[Cu{(NH3)(2)sar}](4+) and lel(3)-[Cu{(NNe3)(2)sar}](4+). Overall, the results show a clear relationship between the stability of a given isomer and its degree of distortion with respect to the ideal octahedron (or trigonal prism), with the latter being ultimately dependent on the transition metal and its radius.

  • 2.
    Bartoszewicz, Agnieszka
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Jezowska, Martina M.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Laymand, Kevin
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Mobus, Juri
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Martín-Matute, Belén
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Synthesis of β-Hydroxy and β-Amino Ketones from Allylic Alcohols Catalyzed by Ru(η5-C5Ph5)(CO)2Cl2012In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 9, p. 1517-1530Article in journal (Refereed)
    Abstract [en]

    An efficient method for the synthesis of beta-hydroxy and beta-amino ketones from allylic alcohols catalyzed by Ru(5-C5Ph5)(CO)2Cl is described. The influence of the stereoelectronic properties of the catalyst on the reaction outcome has been studied. Optimization of the reaction conditions supressed the formation of undesired side products such as saturated ketones, benzyl alcohols, and a,beta-unsaturated ketones. Several aromatic and aliphatic allylic alcohols have been reacted with a large variety of aldehydes or imines to produce beta-hydroxy ketones or beta-amino ketones, respectively, in yields up to 99%. Based on experimental data, a mechanism via ruthenium alkoxides and ruthenium aldoxides is proposed. In addition, a C-bound ruthenium enolate has been characterized.

  • 3.
    Carrasco, Sergio
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Martin-Matute, Belén
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Hydrazine-Free Facile Synthesis of Palladium-Tetrakis(Triphenylphosphine)2019In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 14, p. 1951-1955Article in journal (Refereed)
    Abstract [en]

    We present an easy and very efficient procedure for the synthesis of Pd(PPh3)(4) using nontoxic reducing agents. The complex is obtained in a remarkable 83 % yield, and the method can be scaled up. A very detailed spectroscopic and spectrometric characterization is reported.

  • 4. Das, Biswanath
    et al.
    Daver, Henrik
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Pyrkosz-Bulska, Monika
    Gumienna-Kontecka, Elzbieta
    Himo, Fahmi
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Nordlander, Ebbe
    An Unsymmetric Ligand with a N5O2 Donor Set and Its Corresponding Dizinc Complex: A Structural and Functional Phosphoesterase Model2018In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 36, p. 4004-4013Article in journal (Refereed)
    Abstract [en]

    To mimic the active sites of the hydrolytic enzyme zinc phosphotriesterase, a new dinucleating unsymmetric ligand, PICIMP (2-{[2-hydroxy-5-methyl-3-({[(1-methyl-1H-imidazol-2-yl)methyl](pyridin-2-ylmethyl)amino}methyl)benzyl][(1-methyl-1H-imidazol-2-yl)methyl]amino}acetic acid), has been synthesized and characterized. The hydrolytic efficacy of the complex solution (PICIMP/ZnCl2 = 1:2) has been investigated using bis-(2,4-dinitrophenyl)phosphate (BDNPP), a DNA analogue substrate. Speciation studies were undertaken by potentiometric titrations at varying pH for both the ligand and the corresponding dizinc complex to elucidate the formation of the active hydrolysis catalyst; these studies reveal that the dinuclear zinc(II) complexes, [Zn-2(PICIMP)](2+) and [Zn-2(PICIMP)(OH)](+) predominate in solution above pH 4. The obtained pK(a) of 7.44 for the deprotonation of water suggests formation of a bridging hydroxide between the two Zn-II ions. Kinetic investigations of BDNPP hydrolysis over the pH range 5.5-10.5 have been performed. The cumulative results indicate the hydroxo-bridged dinuclear Zn-II complex [Zn-2(PICIMP)(mu-OH)](+) as the effective catalyst. Density functional theory calculations were performed to investigate the detailed reaction mechanism. The calculations suggest that the bridging hydroxide becomes terminally coordinated to one of the zinc ions before performing the nucleophilic attack in the reaction.

  • 5. Das, Biswanath
    et al.
    Daver, Henrik
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Singh, Amrendra
    Singh, Reena
    Haukka, Matti
    Demeshko, Serhiy
    Meyer, Franc
    Lisensky, George
    Jarenmark, Martin
    Himo, Fahmi
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Nordlander, Ebbe
    A Heterobimetallic FeIIIMnII Complex of an Unsymmetrical Dinucleating Ligand: A Structural and Functional Model Complex for the Active Site of Purple Acid Phosphatase of Sweet Potato2014In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, Vol. 2014, no 13, p. 2204-2212Article in journal (Refereed)
    Abstract [en]

    The heterodinuclear mixed-valence complex [FeMn(ICIMP)(OAc)(2)Cl] (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 Mn-II ion. The phenoxide moiety of the ICIMP ligand and both acetate ligands bridge the two metal ions of the complex. Mossbauer spectroscopy shows that the iron ion in 1 is high-spin Fe-III. Two quasi-reversible redox reactions for the complex, attributed to the (FeMnII)-Mn-III/(FeMnII)-Mn-II (at -0.67 V versus Fc/Fc(+)) and (FeMnII)-Mn-III/(FeMnIII)-Mn-III (at 0.84 V), were observed by means of cyclic voltammetry. Complex 1, with an Fe-III-Mn-II distance of 3.58 angstrom, 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 Mn-II ion. In the transition state, a hydroxide ion that bridges the two metal ions becomes terminally coordinated to the Fe-III ion and acts as a nucleophile, attacking the phosphorus center of BDNPP with the concomitant dissociation of the leaving group.

  • 6.
    Gao, Weiming
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Sun, Junliang
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Li, Mingrun
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Åkermark, Torbjörn
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Romare, Kristina
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Sun, Licheng
    Royal Institute of Technology (KTH), Department of Organic Chemistry.
    Åkermark, Björn
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Synthesis of a [3Fe2S] cluster with low redox potential from [2Fe2S] hydrogenase models: electrochemical and photochemical generation of hydrogen2011In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, Vol. 2011, no 7, p. 1100-1105Article in journal (Refereed)
    Abstract [en]

    In the attempted replacement of carbon monoxide by the bis(phosphane) dppv in a dinuclear [2Fe2S] complex, a trinuclear [3Fe2S] complex with two bis(phosphane) ligands was unexpectedly obtained. On protonation, this gave a bridged hydride complex with an unusually low potential for the reduction of protons to molecular hydrogen. The redox potential also appears sufficiently positive for direct electron transfer from an excited [Ru(bpy)(3)](2+) sensitizer.

  • 7. Huang, Yong
    et al.
    Gao, Weiming
    Åkermark, Torbjörn
    Li, Mingrun
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Åkermark, Björn
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    An Air-Stable Fe3S4 Complex with Properties Similar to Those of the HOXair State of the Diiron Hydrogenases2012In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 27, p. 4259-4263Article in journal (Refereed)
    Abstract [en]

    A Fe3S4 complex bridged by azapropanedithiolate (adt), complex 6, was prepared as a potential model of the HOXair state of [FeFe]-hydrogenases. Complex 6 was characterized by IR and 1H NMR spectroscopy, and its structure was determined by X-ray crystallography. The electrochemical studies show that complex 6 is redox-active under acidic conditions, which provides insight into the catalytic mechanism. Hydrogen evolution, driven by visible light, was observed in CH3CN/D2O solution by online mass spectroscopy.

  • 8. Kravchenko, Ekaterina
    et al.
    Neagu, Alexandra
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Zakharchuk, Kiryl
    Grins, Jekabs
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Svensson, Gunnar
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Pankov, Vladimir
    Yaremchenko, Aleksey A.
    High-Temperature Structural and Electrical Characterization of Reduced Oxygen-Deficient Ruddlesden-Popper Nickelates2018In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 28, p. 3320-3329Article in journal (Refereed)
    Abstract [en]

    High-temperature characterization of oxygen-deficient Sr-rich (La1-xSrx)(2)NiO4-delta (x = 0.5-0.8) solid solutions under mildly reducing conditions with p(O-2) approximate to 5x10(-5) atm was performed by employing structural and thermal analysis, TEM, and electrical conductivity measurements. Oxygen losses from the crystal lattice on reduction were found to result in a reversible transition from the tetragonal (I4/mmm) to the orthorhombic (Immm) structure and shrinkage of the crystal lattice for the compositions with x > 0.5. TEM and thermogravimetric analysis evidenced slow kinetics of the structural transition. The increase in oxygen deficiency under reducing conditions is accompanied by localization of the electronic charge carriers, a drop of the p-type electronic conductivity, and a transition from metallic-like to semiconducting behavior. The extent of changes in oxygen nonstoichiometry, unit--cell dimensions, average Ni oxidation state, electron-hole concentration, and electronic conductivity on reduction is interrelated with the strontium content. The results suggest that the electrical conductivity of (La1-xSrx)(2)NiO4-delta ceramics depends mainly on the average Ni oxidation state.

  • 9. Köppen, Milan
    et al.
    Dhakshinamoorthy, Amarajothi
    Inge, A. Ken
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK). Christian‐Albrechts‐Universität zu Kiel, Germany.
    Cheung, Ocean
    Ångström, Jonas
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Mayer, Peter
    Stock, Norbert
    Synthesis, Transformation, Catalysis, and Gas Sorption Investigations on the Bismuth Metal-Organic Framework CAU-172018In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 30, p. 3496-3503Article in journal (Refereed)
    Abstract [en]

    Very few microporous bismuth metal-organic frameworks have been discovered to date. Of these, no detailed experimental characterization of the synthesis and properties have been reported until now for the only one which can be prepared from inexpensive starting materials: CAU-17 [Bi(BTC)(H2O)], with H3BTC = trimesic acid. In-situ powder X-ray diffraction during solvothermal synthesis of CAU-17 revealed that it crystallizes rapidly within 2 minutes, and if the reaction is not stopped, the MOF transforms into a nonporous dense purely inorganic material within one hour, revealing that CAU-17 is a crystalline intermediate phase. Synthesis scale-up employing more concentrated reaction mixtures resulted in another Bi trimesate of composition [Bi(HBTC)(NO3)(MeOH)]MeOH, which structurally decomposes upon storage under ambient conditions. Sorption experiments showed that CAU-17 is microporous with a BET surface area of 530 m(2)/g. As a potential greenhouse gas sorbent, CAU-17 showed high SF6/N-2 and CO2/N-2 selectivity > 31 and 29, respectively. Furthermore, the catalytic activity of CAU-17 was studied in the regioselective ring-opening of styrene oxide by methanol to obtain 2-methoxy-2-phenylethanol, thus demonstrating the existence of coordinatively unsaturated sites in the crystal structure of CAU-17.

  • 10.
    Lee, Bao-Lin
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Kärkäs, Markus D.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Johnston, Eric V.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Inge, Andrew K.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Tran, Lien-Hoa
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Xu, Yunhua
    Hansson, Örjan
    Zou, Xiaodong
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Åkermark, Björn
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Synthesis and characterization of oligonuclear Ru, Co, and Cu oxidation catalysts2010In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 34, p. 5462-5470Article in journal (Refereed)
    Abstract [en]

    In this work, we report the preparation and crystal structures of three new oligonuclear complexes, Ru-2(bbpmp)(mu-OAc)(3) (4), [Co-2(bbpmp)(mu-OAc)(mu-OMe)](PF6) (5), [Cu-4(Hbbpmp)(2)(mu-OAc)(H2O)(2)](OAc)(PF6)(2) (6) {H(3)bbpmp = 2,6-bis[(2-hydroxybenzyl)-(2-pyridylmethyl)aminomethyl]-4-methylphenol (3)}. The structures of the complexes were determined by single-crystal X-ray diffraction. The oxidation states of ruthenium, cobalt and copper in the complexes are +3, +3 and +2, respectively. In 4 and 5, Ru-III and Co-III are coordinated to four oxygen and two nitrogen atoms in an octahedral geometry, while in 6, Cu-II adopts both octahedral (CuN2O4) and square-pyramidal (CuN2O3) geometry. The potential of the three complexes as oxidation catalysts has been investigated.

  • 11.
    Liao, Rong-Zhen
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Himo, Fahmi
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Yu, Jian-Guo
    Liu, Ruo-Zhuang
    Theoretical study of the RNA hydrolysis mechanism of the dinuclear zinc enzyme RNase Z2009In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, Vol. 2009, no 20, p. 2967-2972Article in journal (Refereed)
    Abstract [en]

    RNase Z is a dinuclear zinc enzyme that catalyzes the removal of the tRNA 3'-end trailer. Density functional theory is used to investigate the phosphodiester hydrolysis mechanism of this enzyme with a model of the active site constructed on the basis of the crystal structure. The calculations imply that the reaction proceeds through two steps. The first step is a nucleophihc attack by a bridging hydroxide coupled with protonation of the leaving group by a Glu-His diad. Subsequently, a water molecule activated by the same Glu-His diad makes a reverse attack, regenerating the bridging hydroxide. The second step is calculated to be the rate-limiting step with a barrier of 18 kcal/mol, in good agreement with experimental kinetic studies. Both zinc ions participate in substrate binding and orientation, facilitating nucleophilic attack. In addition, they act as electrophilic catalysts to stabilize the pentacoordinate trigonal-bipyramidal transition states.

  • 12.
    Liao, Rong-Zhen
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Li, Xi-Chen
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Siegbahn, Per E. M.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Reaction Mechanism of Water Oxidation Catalyzed by Iron Tetraamido Macrocyclic Ligand Complexes - A DFT Study2014In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 4, p. 728-741Article in journal (Refereed)
    Abstract [en]

    Density functional calculations are used to elucidate the reaction mechanism of water oxidation catalyzed by iron tetra-amido macrocyclic ligand (TAML) complexes. The oxidation of the starting TAML-Fe3+-OH2 complex by removing three electrons and two protons leads to the formation of a key intermediate, TAML-Fe5+=O, which can undergo nucleophilic attack by either a water molecule or a nitrate ion. Both pathways involve attack on the oxo group and lead to the production of O-2. The water attack is more favoured and has a total barrier of 15.4 kcal/mol. The alternative nitrate attack pathway has a barrier of 19.5 kcal/mol. Nitrate functions as a cocatalyst by first donating an oxygen atom to the oxo group to form O-2 and a nitrite ion, which can then be reoxidized to regenerate a nitrate ion. Three possible competing pathways result in ligand modification, namely, water and nitrate attack on the ligand, as well as ligand amide oxidation. The water attack on the ligand has a low barrier of only 10.9 kcal/mol and leads to the opening of the benzene ring, which explains the observation of fast catalyst degradation. The lack of activity or lower activity of other catalysts with different substituents is also rationalized.

  • 13.
    Motwani, Hitesh
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Shimakoshi, Hisashi
    Department of Chemistry and Biochemistry, Kyushu University.
    Golding, Bernard
    School of Chemistry, Newcastle University.
    Törnqvist, Margareta
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Environmental Chemistry.
    Hisaeda, Yoshio
    Department of Chemistry and Biochemistry, Kyushu University.
    Formation of an alkylcobyrinate from sucralose and mechanistic aspects of its Co-C bond cleavagesIn: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948Article in journal (Other academic)
  • 14.
    Nyhlén, Jonas
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Privalov, Timofei
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    "Frustration" of orbital interactions in Lewis base/Lewis acid adducts: a computational study of H2 uptake by phosphanylboranes R2P=BR'22009In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 19, p. 2759-2764Article in journal (Refereed)
    Abstract [en]

    The reaction of mol. hydrogen with phosphanylboranes R2P:BR'2 (1) is systematically studied by d. functional theory calcns. and second order Moller-Plesset perturbation theory. The potential energy barriers and the exothermicity of H2 uptake are reported for a series of phosphanylboranes with different electron-donating and -withdrawing groups bound to phosphorus and boron. Systematic MO anal. reveals that the "frustration" between boron and phosphorus can be increased by modifying the substituents, and thus, AO interactions could be exploited in order to increase the reactivity of 1. Addnl., authors found a correlation between the potential energy barrier for H2 uptake and the energy of the HOMO of the P:B complex, which could be relevant for the prediction of the properties of candidate compds. for H2 activation and therefore useful for the development of such systems. [on SciFinder(R)]

  • 15.
    Popović-Bijelić, Ana
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Kowol, Christian R.
    Lind, Maria E. S.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Luo, Jinghui
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Himo, Fahmi
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Enyedy, Éva A.
    Arion, Vladimir B.
    Gräslund, Astrid
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Ribonucleotide reductase inhibition by metal complexes of Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone): A combined experimental and theoretical study2011In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, Vol. 105, no 11, p. 1422-1431Article in journal (Refereed)
    Abstract [en]

    Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone, 3-AP) is currently the most promising chemotherapeutic compound among the class of α-N-heterocyclic thiosemicarbazones. Here we report further insights into the mechanism(s) of anticancer drug activity and inhibition of mouse ribonucleotide reductase (RNR) by Triapine. In addition to the metal-free ligand, its iron(III), gallium(III), zinc(II) and copper(II) complexes were studied, aiming to correlate their cytotoxic activities with their effects on the diferric/tyrosyl radical center of the RNR enzyme in vitro. In this study we propose for the first time a potential specific binding pocket for Triapine on the surface of the mouse R2 RNR protein. In our mechanistic model, interaction with Triapine results in the labilization of the diferric center in the R2 protein. Subsequently the Triapine molecules act as iron chelators. In the absence of external reductants, and in presence of the mouse R2 RNR protein, catalytic amounts of the iron(III)–Triapine are reduced to the iron(II)–Triapine complex. In the presence of an external reductant (dithiothreitol), stoichiometric amounts of the potently reactive iron(II)–Triapine complex are formed. Formation of the iron(II)–Triapine complex, as the essential part of the reaction outcome, promotes further reactions with molecular oxygen, which give rise to reactive oxygen species (ROS) and thereby damage the RNR enzyme. Triapine affects the diferric center of the mouse R2 protein and, unlike hydroxyurea, is not a potent reductant, not likely to act directly on the tyrosyl radical.

  • 16.
    Privalov, Timofei
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    The role of amine-B(C6F5)3 adducts in the catalytic reduction of imines with H2: a computational study2009In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 15, p. 2229-2237Article in journal (Refereed)
  • 17.
    Shatskiy, Andrey
    et al.
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    Kärkäs, Markus D.
    Åkermark, Björn
    Stockholm University, Faculty of Science, Department of Organic Chemistry.
    The Art of Splitting Water: Storing Energy in a Readily Available and Convenient Form2019In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 15, p. 2020-2024Article in journal (Refereed)
    Abstract [en]

    This essay for EurJIC's special issue on Redox Catalysis for Artificial Photosynthesis introduces the reader to the field of water oxidation using molecular catalysts. The most essential challenge our society must address during the 21st century is perhaps the realization of a system for producing sustainable energy on the global scale. Currently, there exists an urgent need to develop effective and economical carbon-neutral or carbon-free energy technologies. The production of solar fuels through water splitting constitutes a key enabling element. The construction of robust and efficient catalysts for oxidation of water is therefore essential. In this essay the progress and mechanistic considerations pertaining to molecular water oxidation catalysts are described and discussed from a personal perspective.

  • 18.
    Zimmermann, Iwan
    et al.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Johnsson, Mats
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Lidin, Sven
    Crystalline Iron Oxohalide Nanotube Pea Pods2012In: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, no 25, p. 3971-3974Article in journal (Refereed)
    Abstract [en]

    Compounds Fe7Sb3(PO4)3O6Cl3 and Fe7Sb3(PO4)3O6Br3 are the first iron phosphates containing SbIII. They were synthesized by chemical vapor transport reactions, and their crystal structures were characterized by single-crystal X-ray diffraction. The compounds are isostructural and crystallize in the orthorhombic space group Pnma. Tubular Fe7(PO4)3O6X3 units (X = Cl, Br) are linked by SbO4 groups to build up a framework. The tubular units consist of an outer part made up of [FeO5X] octahedra where the Fe atoms are arranged to resemble a nanotube. Inside the tubes there are phosphate groups, and at the very center there is a chain of face-sharing [FeO6] octahedra.

1 - 18 of 18
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf