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Stott LA, Prosser KE, Berdichevsky EK, Walsby CJ, Warren JJ. Lowering water oxidation overpotentials using the ionisable imidazole of copper(2-(2'-pyridyl)imidazole). Chem Commun (Camb) 2017; 53:651-654. [PMID: 27990513 DOI: 10.1039/c6cc09208j] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Rapid and low overpotential oxidation of water to dioxygen remains a key hurdle for storage of solar energy. Here, we address this issue by demonstrating that deprotonation of 2-(2'-pyridyl)-imidazole (pimH)-ligated copper complexes promotes water oxidation at low overpotential and low catalyst loading. This improves upon other work on homogeneous copper-based water oxidation catalysts, which are highly active, but limited by high overpotentials. EPR and UV-vis spectroscopic evaluation of catalyst speciation shows that at pH ≥ 12 coordinated pimH is deprotonated and a bis(hydroxide) Cu2+ active catalyst forms. Rapid electrochemical water oxidation (35 s-1, 0.85 V onset potential) was observed with 150 μM catalyst. These results demonstrate that catalytic water oxidation potentials can be shifted by hundreds of mV in homogeneous metal catalysts bearing an ionisable imidazole ligand.
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Affiliation(s)
- Leea A Stott
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby BC V5A 1S6, Canada.
| | - Kathleen E Prosser
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby BC V5A 1S6, Canada.
| | - Ellan K Berdichevsky
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby BC V5A 1S6, Canada.
| | - Charles J Walsby
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby BC V5A 1S6, Canada.
| | - Jeffrey J Warren
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby BC V5A 1S6, Canada. and Canadian Institute for Applied Research, CIFAR Azrieli Global Scholar and Bio-Inspired Solar Energy Programs, Toronto, ON M5G 1Z8, Canada
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2
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Gray JL, Gerlach DL, Papish ET. Crystal structure of (perchlorato-κ O)(1,4,7,10-tetra-aza-cyclo-dodecane-κ 4N)copper(II) perchlorate. Acta Crystallogr E Crystallogr Commun 2017; 73:31-34. [PMID: 28083129 PMCID: PMC5209765 DOI: 10.1107/s2056989016019563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 12/06/2016] [Indexed: 11/10/2022]
Abstract
The crystal structure of the title salt, [Cu(ClO4)(C8H20N4)]ClO4, is reported. The CuII ion exhibits a square-pyramidal geometry and is coordinated by the four N atoms of the neutral 1,4,7,10-tetra-aza-cyclo-dodecane (cyclen) ligand and an O atom from one perchlorate anion, with the second perchlorate ion hydrogen-bonded to one of the amine N atoms of the cyclen ligand. Additional N-H⋯O hydrogen bonds between the amine H atoms and the coordinating and non-coordinating perchlorate groups create a three-dimensional network structure. Crystals were grown from a concentrated methanol solution at ambient temperature, resulting in no co-crystallization of solvent.
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Affiliation(s)
- Jessica L. Gray
- Department of Chemistry, University of Alabama, 250 Hackberry Lane, Tuscaloosa, AL 35487-0336, USA
| | - Deidra L. Gerlach
- Department of Chemistry, University of Alabama, 250 Hackberry Lane, Tuscaloosa, AL 35487-0336, USA
| | - Elizabeth T. Papish
- Department of Chemistry, University of Alabama, 250 Hackberry Lane, Tuscaloosa, AL 35487-0336, USA
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Zhang X, Liu X, Phillips DL, Zhao C. Mechanistic Insights Into the Factors That Influence the DNA Nuclease Activity of Mononuclear Facial Copper Complexes Containing Hetero-Substituted Cyclens. ACS Catal 2015. [DOI: 10.1021/acscatal.5b01735] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xuepeng Zhang
- MOE
Key Laboratory of Bioinorganic and Synthetic Chemistry, School of
Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Xueping Liu
- MOE
Key Laboratory of Bioinorganic and Synthetic Chemistry, School of
Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - David Lee Phillips
- Department
of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Cunyuan Zhao
- MOE
Key Laboratory of Bioinorganic and Synthetic Chemistry, School of
Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
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Mehlenbacher MR, Bou-Abdallah F, Liu XX, Melman A. Calorimetric studies of ternary complexes of Ni(II) and Cu(II) nitrilotriacetic acid and N-acetyloligohistidines. Inorganica Chim Acta 2015. [DOI: 10.1016/j.ica.2015.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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5
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Kinetics and speciation of paraoxon hydrolysis by zinc(II)–azamacrocyclic catalysts. Inorganica Chim Acta 2015. [DOI: 10.1016/j.ica.2015.07.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Lönnberg T, Hutchinson M, Rokita S. Selective Alkylation of C-Rich Bulge Motifs in Nucleic Acids by Quinone Methide Derivatives. Chemistry 2015. [PMID: 26220692 DOI: 10.1002/chem.201502014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A quinone methide precursor featuring a bis-cyclen anchoring moiety has been synthesized and its capacity to alkylate oligonucleotide targets quantified in the presence and absence of divalent metal ions (Zn(2+) , Ni(2+) and Cd(2+) ). The oligonucleotides were designed for testing the sequence and secondary structure specificity of the reaction. Gel electrophoretic analysis revealed predominant alkylation of C-rich bulges, regardless of the presence of divalent metal ions or even the bis-cyclen anchor. This C-selectivity appears to be an intrinsic property of the quinone methide electrophile as reflected by its reaction with an equimolar mixture of the 2'-deoxynucleosides. Only dA-N1 and dC-N3 alkylation products were detected initially and only the dC adduct persisted for detection under conditions of the gel electrophoretic analysis.
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Affiliation(s)
- Tuomas Lönnberg
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (USA). .,Department of Chemistry, University of Turku, 20014 Turku (Finland).
| | - Mark Hutchinson
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (USA)
| | - Steven Rokita
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (USA)
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Siters KE, Fountain MA, Morrow JR. Selective binding of Zn2+ complexes to human telomeric G-quadruplex DNA. Inorg Chem 2014; 53:11540-51. [PMID: 25310175 DOI: 10.1021/ic501484p] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Zn(2+) complex of 5-(1,4,7,10-tetraazacyclododecan-1-ylsulfonyl)-N,N-dimethylnaphthalen-1-amine, Zn(DSC), binds selectively to the biologically relevant human telomeric (H-Telo) G-quadruplex. An increase in the Zn(DSC) dansyl group fluorescence with a simultaneous shift in emission is consistent with the complex binding to H-Telo. The H-Telo G-quadruplex has two binding sites for Zn(DSC) with binding constants in the low micromolar range (2.5 μM). Isothermal calorimetric titrations confirm low micromolar dissociation constants with a 2:1 stoichiometry. The interaction between H-Telo and Zn(DSC) is highly pH-dependent, consistent with binding to the unpaired thymines in the G-quadruplex loops. As a result, Zn(DSC) selectively binds to H-Telo over duplex DNA. In contrast to Zn(2+), Fe(2+) and Co(2+) do not complex to the DSC macrocycle appreciably under the conditions of the experiment. The Cu(2+) complex of DSC does not interact measurably with the H-Telo G-quadruplex. Interestingly, the H-Telo-Zn(DSC) adduct self-assembles from its individual components at physiological pH and 100 mM KCl. The self-assembly feature, which is specific for the Zn(2+) ion, suggests that this system may be viable as a Zn(2+) sensor. Pentanucleotides were studied in order to better describe the binding of Zn(DSC) to thymine sequences. NMR studies were consistent with the binding of Zn(DSC) to thymine-containing oligonucleotides including CCTCC, CTTCC, and CTCTC. Studies showed that the dansyl group of Zn(DSC) interacts with thymines in CTTCC. Fluorescence spectroscopy and ITC data indicate that Zn(DSC) forms 2:1 adducts with thymines that are spaced (CTCTC) but not tandem thymines (CTTCC). These data are consistent with one Zn(DSC) complex binding to two separate loops in the G-quadruplex. A second Zn(2+) complex containing an acridine pendent, Zn(ACR), binds tightly to pentanucleotides with both tandem and spaced thymines. Zn(ACR) indiscriminately binds to both H-Telo and duplex DNA.
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Affiliation(s)
- Kevin E Siters
- Department of Chemistry, University at Buffalo, State University of New York , Buffalo, New York 14260, United States
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Kim JH, Lee JH, Lee DW. Hydrolysis of Phosphate Esters Mediated by New Unsymmetrical Binuclear Cu Complex. B KOREAN CHEM SOC 2012. [DOI: 10.5012/bkcs.2012.33.6.2037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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9
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Analytical determination of apparent stability constants using a copper ion selective electrode. J Inorg Biochem 2011; 105:1656-61. [DOI: 10.1016/j.jinorgbio.2011.07.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 06/27/2011] [Accepted: 07/23/2011] [Indexed: 11/22/2022]
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Vargová Z, Balentová E, Walko M, Arabuli L, Hermann P, Lukeš I. Amino acids binding to Zn2+-cyclen molecular receptor in aqueous solution. J Mol Recognit 2011; 24:295-302. [DOI: 10.1002/jmr.1059] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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Vargová Z, Almáši M, Arabuli L, Györyová K, Zeleňák V, Kuchár J. Utilization of IR spectral detailed analysis for coordination mode determination in novel Zn-cyclen-aminoacid complexes. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:788-793. [PMID: 21216184 DOI: 10.1016/j.saa.2010.12.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 11/18/2010] [Accepted: 12/08/2010] [Indexed: 05/30/2023]
Abstract
The infrared spectra, elemental and thermal (TG/DTG and DTA) analyses of novel [Zn(cyclen-κ4N1,4,7,10)(HGly-κ2O,O')](ClO4)2 (1), and [Zn2(cyclen-κ4N1,4,7,10)2(μ-S-Ala-κ2N,O)](ClO4)(3)·2H2O (2) complexes (cyclen - 1,4,7,10-tetraazacyclododecane) were recorded and analyzed in the relation to their structural peculiarities. IR spectral data indicate both mono- or bidentate coordination mode of a carboxylate group in the prepared complexes (at pH≈9). The results indicate unusual bidentate carboxylate coordination mode (in complex (1)) toward to Zn2+-cyclen unit. Therefore the crystal structure determination of the crystalline complex [Zn(cyclen-κ4N1,4,7,10)(NO3-κ2O,O')](NO3) was attached in order to support the coordination mode assignment in complex (1).
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Affiliation(s)
- Z Vargová
- Department of Inorganic chemistry, Institute of Chemistry, University of P.J. Šafárik, 04154 Košice, Slovak Republic.
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12
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Zinc(II)cyclen–peptide conjugates interacting with the weak effector binding state of Ras. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2010.07.067] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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13
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Gruber B, Stadlbauer S, Woinaroschy K, König B. Luminescent vesicular receptors for the recognition of biologically important phosphate species. Org Biomol Chem 2010; 8:3704-14. [DOI: 10.1039/c004916f] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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14
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Riechers A, Schmidt F, Stadlbauer S, König B. Detection of Protein Phosphorylation on SDS-PAGE Using Probes with a Phosphate-Sensitive Emission Response. Bioconjug Chem 2009; 20:804-7. [DOI: 10.1021/bc9000307] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexander Riechers
- Institute for Organic Chemistry, University of Regensburg, Regensburg, Germany
| | - Florian Schmidt
- Institute for Organic Chemistry, University of Regensburg, Regensburg, Germany
| | - Stefan Stadlbauer
- Institute for Organic Chemistry, University of Regensburg, Regensburg, Germany
| | - Burkhard König
- Institute for Organic Chemistry, University of Regensburg, Regensburg, Germany
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15
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Gilson R, Durrant MC. Estimation of the pKa values of water ligands in transition metal complexes using density functional theory with polarized continuum model solvent corrections. Dalton Trans 2009:10223-30. [DOI: 10.1039/b911593e] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Proteolytic activity of Co(III) complex of 1-oxa-4,7,10-triazacyclododecane: a new catalytic center for peptide-cleavage agents. J Biol Inorg Chem 2008; 14:151-7. [PMID: 18836752 DOI: 10.1007/s00775-008-0434-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Accepted: 09/25/2008] [Indexed: 10/21/2022]
Abstract
Catalytic drugs based on target-selective artificial proteases have been proposed as a new paradigm in drug design. Peptide-cleavage agents selective for pathogenic proteins of Alzheimer's disease, type 2 diabetes mellitus or Parkinson's disease have been prepared using the Co(III) aqua complex (Co(III)cyclen) of 1,4,7,10-tetraazacyclododecane as the catalytic center. In the present study, the Co(III) aqua complex (Co(III)oxacyclen) of 1-oxa-4,7,10-triazacyclododecane was examined in search of an improved catalytic center for peptide-cleavage agents. An X-ray crystallographic study of [Co(oxacyclen)(CO(3))](ClO(4)), titration of Co(III)oxacyclen, and kinetic studies on the cleavage of albumin, gamma-globulin, lysozyme, and myoglobin by Co(III)oxacyclen were carried out. Considerably higher proteolytic activity was observed for Co(III)oxacyclen in comparison with Co(III)cyclen, indicating that better target-selective artificial metalloproteases would be obtained using Co(III)oxacyclen as the catalytic center. The improved proteolytic activity was attributed to either steric effects or the increased Lewis acidity of the Co(III) center. The kinetic data also predicted that side effects due to the cleavage of nontarget proteins by a catalytic drug based on Co(III)oxacyclen would be insignificant.
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Grauer A, Riechers A, Ritter S, König B. Synthetic Receptors for the Differentiation of Phosphorylated Peptides with Nanomolar Affinities. Chemistry 2008; 14:8922-8927. [DOI: 10.1002/chem.200800432] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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18
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Mirams RE, Smith SJ, Hadler KS, Ollis DL, Schenk G, Gahan LR. Cadmium(II) complexes of the glycerophosphodiester-degrading enzyme GpdQ and a biomimetic N,O ligand. J Biol Inorg Chem 2008; 13:1065-72. [PMID: 18535849 DOI: 10.1007/s00775-008-0392-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Accepted: 05/23/2008] [Indexed: 11/30/2022]
Abstract
The glycerophosphodiester-degrading enzyme GpdQ from Enterobacter aerogenes is a promising bioremediator owing to its ability to degrade some organophosphate pesticides and diester products originating from the hydrolysis of nerve agents such as VX. Here, the cadmium derivative of GpdQ was prepared by reconstituting the apoenzyme. Catalytic measurements with (Cd(2+))(2)-GpdQ and the phosphodiester substrate bis(4-nitrophenyl)phosphate yield k(cat) = 15 s(-1). The pK(a) of 9.4, determined from the pH dependence of the catalytic activity, implicates a hydroxide ligand as the catalytic nucleophile. Also prepared was the cadmium-containing biomimetic [Cd(2)((HP)(2)B)(OAc)(2)(OH(2))](PF(6)) (where (HP)(2)B is [2,6-bis([(2-pyridylmethyl)(2-hydroxyethyl)amino]methyl)-4-methylphenol]), which mimics the asymmetry of the metal ion coordination in the active site of GpdQ. The phosphoesterase-like activity of [Cd(2)((HP)(2)B)(OAc)(2)(OH(2))](PF(6)) was studied using the substrate bis(2,4-dinitrophenyl)phosphate, yielding a kinetically relevant pK(a) of 8.9, with k(cat) = 0.004 s(-1). In summary, the model is both an adequate structural and a reasonable functional mimic of GpdQ.
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Affiliation(s)
- Ruth E Mirams
- School of Molecular and Microbial Sciences, The University of Queensland, St. Lucia, QLD, 4072, Australia
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Koo CK, Chow CF, Chiu BKW, Lei NY, Lam MHW, Wong WY. A Pair of Coordination Donor–Acceptor Ensembles for the Detection of Tartrate in Aqueous Media. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200700931] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Jang SW, Suh J. Proteolytic Activity of Cu(II) Complex of 1-Oxa-4,7,10-triazacyclododecane. Org Lett 2008; 10:481-4. [DOI: 10.1021/ol702860h] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Seung Woo Jang
- Department of Chemistry, Seoul National University, Seoul 151-747, Korea
| | - Junghun Suh
- Department of Chemistry, Seoul National University, Seoul 151-747, Korea
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Vargová Z, Kotek J, Rudovský J, Plutnar J, Gyepes R, Hermann P, Györyová K, Lukeš I. Ternary Complexes of Zinc(II), Cyclen and Pyridinecarboxylic Acids. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700183] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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