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Pérez AL, Kemmerer A, Zapata AJ, Sartoris R, Gonzalez PJ, Urteaga R, Baggio R, Suarez S, Ramos CA, Dalosto SD, Rizzi AC, Brondino CD. Synthesis, structure, and characterisation of a ferromagnetically coupled dinuclear complex containing Co(II) ions in a high spin configuration and thiodiacetate and phenanthroline as ligands and of a series of isomorphous heterodinuclear complexes containing different Co : Zn ratios. Dalton Trans 2023; 52:14595-14605. [PMID: 37786344 DOI: 10.1039/d3dt02115g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
We report the synthesis, crystal structure, and characterisation of a dinuclear Co(II) compound with thiodiacetate (tda) and phenanthroline (phen) as ligands (1), and of a series of metal complexes isomorphous to 1 with different Co : Zn ratios (2, 4 : 1; 3, 1 : 1; 4, 1 : 4; 5, 1 : 10). General characterisation methodologies and X-ray data showed that all the synthesised complexes are isomorphous to Zn(II) and Cu(II) analogues (CSD codes: DUHXEL and BEBQII). 1 consists of centrosymmetric Co(II) ion dimers in which the ions are 3.214 Å apart, linked by two μ-O bridges. Each cobalt atom is in a distorted octahedral environment of the N2O3S type. UV-vis spectra of 1 and 5 are in line with high spin (S = 3/2) Co(II) ions in octahedral coordination and indicate that the electronic structure of both Co(II) ions in the dinuclear unit does not significantly change relative to that of the magnetically isolated Co(II) ion. EPR spectra of powder samples of 5 (Co : Zn ratio of 1 : 10) together with spectral simulation indicated high spin Co(II) ions with high rhombic distortion of the zfs [E/D = 0.31(1), D > 0]. DC magnetic susceptibility experiments on 1 and analysis of the data constraining the E/D value obtained by EPR yielded g = 2.595(7), |D| = 61(1) cm-1, and an intradimer ferromagnetic exchange coupling of J = 1.39(4) cm-1. EPR spectra as a function of Co : Zn ratio for both powder and single crystal samples confirmed that they result from two effective S' = 1/2 spins that interact through dipolar and isotropic exchange interactions to yield magnetically isolated S' = 1 centres and that interdimeric exchange interactions, putatively mediated by hydrophobic interactions between phen moieties, are negligible. The latter observation contrasts with that observed in the Cu(II) analogue, where a transition from S = 1 to S' = 1/2 was observed. Computational calculations indicated that the absence of the interdimeric exchange interaction in 1 is due to a lower Co(II) ion spin density delocalisation towards the metal ligands.
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Affiliation(s)
- Ana L Pérez
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral and CONICET, Ciudad Universitaria, S3000ZAA Santa Fe, Argentina.
- Instituto de Física del Litoral, Universidad Nacional del Litoral - CONICET, Güemes 3450, 3000 Santa Fe, Argentina
| | - Axel Kemmerer
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral and CONICET, Ciudad Universitaria, S3000ZAA Santa Fe, Argentina.
| | - Alejandro J Zapata
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral and CONICET, Ciudad Universitaria, S3000ZAA Santa Fe, Argentina.
| | - Rosana Sartoris
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral and CONICET, Ciudad Universitaria, S3000ZAA Santa Fe, Argentina.
| | - Pablo J Gonzalez
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral and CONICET, Ciudad Universitaria, S3000ZAA Santa Fe, Argentina.
| | - Raul Urteaga
- Instituto de Física del Litoral, Universidad Nacional del Litoral - CONICET, Güemes 3450, 3000 Santa Fe, Argentina
- Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, 3000 Santa Fe, Argentina
| | - Ricardo Baggio
- Gerencia de Investigación y Aplicaciones, Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica, Buenos Aires, Argentina
| | - Sebastián Suarez
- Gerencia de Investigación y Aplicaciones, Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica, Buenos Aires, Argentina
| | - Carlos A Ramos
- Instituto de Nanociencia y Nanotecnología, CNEA-CONICET, Centro Atómico Bariloche, 8400, San Carlos de Bariloche, Río Negro, Argentina
| | - Sergio D Dalosto
- Instituto de Física del Litoral, Universidad Nacional del Litoral - CONICET, Güemes 3450, 3000 Santa Fe, Argentina
- Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, 3000 Santa Fe, Argentina
| | - Alberto C Rizzi
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral and CONICET, Ciudad Universitaria, S3000ZAA Santa Fe, Argentina.
| | - Carlos D Brondino
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral and CONICET, Ciudad Universitaria, S3000ZAA Santa Fe, Argentina.
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2
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Nößler M, Neuman NI, Böser L, Jäger R, Singha Hazari A, Hunger D, Pan Y, Lücke C, Bens T, van Slageren J, Sarkar B. Spin Crossover and Fluorine-Specific Interactions in Metal Complexes of Terpyridines with Polyfluorocarbon Tails. Chemistry 2023; 29:e202301246. [PMID: 37191067 DOI: 10.1002/chem.202301246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 05/17/2023]
Abstract
In coordination chemistry and materials science, terpyridine ligands are of great interest, due to their ability to form stable complexes with a broad range of transition metal ions. We report three terpyridine ligands containing different perfluorocarbon (PFC) tails on the backbone and the corresponding FeII and CoII complexes. The CoII complexes display spin crossover close to ambient temperature, and the nature of this spin transition is influenced by the length of the PFC tail on the ligand backbone. The electrochemical properties of the metal complexes were investigated with cyclic voltammetry revealing one oxidation and several reduction processes. The fluorine-specific interactions were investigated by EPR measurements. Analysis of the EPR spectra of the complexes as microcrystalline powders and in solution reveals exchange-narrowed spectra without resolved hyperfine splittings arising from the 59 Co nucleus; this suggests complex aggregation in solution mediated by interactions of the PFC tails. Interestingly, addition of perfluoro-octanol in different ratios to the acetonitrile solution of the sample resulted in the disruption of the F ⋯ ${\cdots }$ F interactions of the tails. To the best of our knowledge, this is the first investigation of fluorine-specific interactions in metal complexes through EPR spectroscopy, as exemplified by exchange narrowing.
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Affiliation(s)
- Maite Nößler
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany
| | - Nicolás I Neuman
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
- Instituto de Desarrollo Tecnológico para la Industria Química, INTEC, UNL-CONICET Predio CCT Conicet "Dr. Alberto Cassano", Colectora RN 168, Km 0, Paraje El Pozo, 3000, Santa Fe, Argentina
| | - Lisa Böser
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany
| | - René Jäger
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany
| | - Arijit Singha Hazari
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - David Hunger
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Yixian Pan
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Clemens Lücke
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Tobias Bens
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Joris van Slageren
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Biprajit Sarkar
- Institut für Chemie und Biochemie, Freie Universität Berlin, Fabeckstraße 34-36, 14195, Berlin, Germany
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
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3
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Meier AA, Moon HJ, Sabuncu S, Singh P, Ronnebaum TA, Ou S, Douglas JT, Jackson TA, Moënne-Loccoz P, Mure M. Insight into the Spatial Arrangement of the Lysine Tyrosylquinone and Cu 2+ in the Active Site of Lysyl Oxidase-like 2. Int J Mol Sci 2022; 23:ijms232213966. [PMID: 36430446 PMCID: PMC9694262 DOI: 10.3390/ijms232213966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/31/2022] [Accepted: 11/08/2022] [Indexed: 11/16/2022] Open
Abstract
Lysyl oxidase-2 (LOXL2) is a Cu2+ and lysine tyrosylquinone (LTQ)-dependent amine oxidase that catalyzes the oxidative deamination of peptidyl lysine and hydroxylysine residues to promote crosslinking of extracellular matrix proteins. LTQ is post-translationally derived from Lys653 and Tyr689, but its biogenesis mechanism remains still elusive. A 2.4 Å Zn2+-bound precursor structure lacking LTQ (PDB:5ZE3) has become available, where Lys653 and Tyr689 are 16.6 Å apart, thus a substantial conformational rearrangement is expected to take place for LTQ biogenesis. However, we have recently shown that the overall structures of the precursor (no LTQ) and the mature (LTQ-containing) LOXL2s are very similar and disulfide bonds are conserved. In this study, we aim to gain insights into the spatial arrangement of LTQ and the active site Cu2+ in the mature LOXL2 using a recombinant LOXL2 that is inhibited by 2-hydrazinopyridine (2HP). Comparative UV-vis and resonance Raman spectroscopic studies of the 2HP-inhibited LOXL2 and the corresponding model compounds and an EPR study of the latter support that 2HP-modified LTQ serves as a tridentate ligand to the active site Cu2. We propose that LTQ resides within 2.9 Å of the active site of Cu2+ in the mature LOXL2, and both LTQ and Cu2+ are solvent-exposed.
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Affiliation(s)
- Alex A. Meier
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
| | - Hee-Jung Moon
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
| | - Sinan Sabuncu
- Department of Chemical Physiology and Biochemistry, School of Medicine, Oregon Health & Science University, Portland, OR 97239, USA
| | - Priya Singh
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
| | - Trey A. Ronnebaum
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
| | - Siyu Ou
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
| | - Justin T. Douglas
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
| | - Timothy A. Jackson
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
| | - Pierre Moënne-Loccoz
- Department of Chemical Physiology and Biochemistry, School of Medicine, Oregon Health & Science University, Portland, OR 97239, USA
| | - Minae Mure
- Department of Chemistry, The University of Kansas, Lawrence, KS 66045, USA
- Correspondence:
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4
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Crespi AF, Zomero PN, Sánchez VM, Pérez AL, Brondino CD, Vega D, Rodríguez-Castellón E, Lázaro-Martínez JM. Solid‐State Characterization of Acetylpyridine Copper Complexes for the Activation Of H2O2 in Advanced Oxidation Processes. Chempluschem 2022; 87:e202200169. [DOI: 10.1002/cplu.202200169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/17/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Ayelén F. Crespi
- Universidad de Buenos Aires Facultad de Farmacia y Bioquimica Chemistry Buenos Aires ARGENTINA
| | - Paula N. Zomero
- Universidad de Buenos Aires Facultad de Farmacia y Bioquimica Chemistry Buenos Aires ARGENTINA
| | - Verónica M. Sánchez
- Universidad Nacional de San Martín: Universidad Nacional de San Martin Chemistry Buenos Aires ARGENTINA
| | - Ana L. Pérez
- Universidad Nacional del Litoral Facultad de Bioquimica y Ciencias Biologicas Physics Santa Fé ARGENTINA
| | - Carlos D. Brondino
- Universidad Nacional del Litoral Facultad de Bioquimica y Ciencias Biologicas Physics Santa Fé ARGENTINA
| | - Daniel Vega
- CNEA: Comision Nacional de Energia Atomica Condensed Matter Physics Buenos Aires ARGENTINA
| | | | - Juan Manuel Lázaro-Martínez
- Universidad de Buenos Aires Facultad de Farmacia y Bioquimica Chemistry Junín 956 1113 Ciudad Autónoma de Buenos Aires ARGENTINA
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5
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Pérez AL, Kemmerer A, Baggio R, Ramos CA, Dalosto SD, Passeggi MCG, Rizzi AC, Brondino CD. EPR, Magnetic, and Computational Characterization of Linear and Zigzag Ladder‐type Chains of Exchange Coupled Cu(II) Complexes with Picolinic and Dipicolinic Acid Ligands. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ana L. Pérez
- Departamento de Física Facultad de Bioquímica y Ciencias Biológicas Universidad Nacional del Litoral – CONICET Ciudad Universitaria S3000ZAA Santa Fe Argentina
| | - Axel Kemmerer
- Departamento de Física Facultad de Bioquímica y Ciencias Biológicas Universidad Nacional del Litoral – CONICET Ciudad Universitaria S3000ZAA Santa Fe Argentina
| | - Ricardo Baggio
- Gerencia de Investigación y Aplicaciones Centro Atómico Constituyentes Comisión Nacional de Energía Atómica Buenos Aires Argentina
| | - Carlos A. Ramos
- Centro Atómico Bariloche Comisión Nacional de Energía Atómica Av. Bustillo 9500 8400 Bariloche Río Negro Argentina
| | - Sergio D. Dalosto
- Instituto de Física del Litoral Universidad Nacional del Litoral – CONICET Güemes 3450 3000 Santa Fe Argentina
| | - Mario C. G. Passeggi
- Instituto de Física del Litoral Universidad Nacional del Litoral – CONICET Güemes 3450 3000 Santa Fe Argentina
| | - Alberto C. Rizzi
- Departamento de Física Facultad de Bioquímica y Ciencias Biológicas Universidad Nacional del Litoral – CONICET Ciudad Universitaria S3000ZAA Santa Fe Argentina
| | - Carlos D. Brondino
- Departamento de Física Facultad de Bioquímica y Ciencias Biológicas Universidad Nacional del Litoral – CONICET Ciudad Universitaria S3000ZAA Santa Fe Argentina
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6
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Stubbe J, Neuman NI, McLellan R, Sommer MG, Nößler M, Beerhues J, Mulvey RE, Sarkar B. Isomerization Reactions in Anionic Mesoionic Carbene-Borates and Control of Properties and Reactivities in the Resulting Co II Complexes through Agostic Interactions. Angew Chem Int Ed Engl 2021; 60:499-506. [PMID: 33080102 PMCID: PMC7839553 DOI: 10.1002/anie.202013376] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Indexed: 12/31/2022]
Abstract
We present herein anionic borate-based bi-mesoionic carbene compounds of the 1,2,3-triazol-4-ylidene type that undergo C-N isomerization reactions. The isomerized compounds are excellent ligands for CoII centers. Strong agostic interactions with the "C-H"-groups of the cyclohexyl substituents result in an unusual low-spin square planar CoII complex, which is unreactive towards external substrates. Such agostic interactions are absent in the complex with phenyl substituents on the borate backbone. This complex displays a high-spin tetrahedral CoII center, which is reactive towards external substrates including dioxygen. To the best of our knowledge, this is also the first investigation of agostic interactions through single-crystal EPR spectroscopy. We conclusively show here that the structure and properties of these CoII complexes can be strongly influenced through interactions in the secondary coordination sphere. Additionally, we unravel a unique ligand rearrangement for these classes of anionic mesoionic carbene-based ligands.
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Affiliation(s)
- Jessica Stubbe
- Institut für Chemie und BiochemieAnorganische ChemieFreie Universität BerlinFabeckstrasse 34–3614195BerlinGermany
| | - Nicolás I. Neuman
- Institut für Chemie und BiochemieAnorganische ChemieFreie Universität BerlinFabeckstrasse 34–3614195BerlinGermany
- Instituto de Desarrollo Tecnológico para la Industria Química CCT Santa Fe CONICET-UNLColectora Ruta Nacional 168, Km 472, Paraje El Pozo3000Santa FeArgentina
| | - Ross McLellan
- WestCHEMDepartment of Pure & Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Michael G. Sommer
- Institut für Chemie und BiochemieAnorganische ChemieFreie Universität BerlinFabeckstrasse 34–3614195BerlinGermany
| | - Maite Nößler
- Institut für Chemie und BiochemieAnorganische ChemieFreie Universität BerlinFabeckstrasse 34–3614195BerlinGermany
| | - Julia Beerhues
- Lehrstuhl für Anorganische KoordinationschemieInstitut für Anorganische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Robert E. Mulvey
- WestCHEMDepartment of Pure & Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Biprajit Sarkar
- Institut für Chemie und BiochemieAnorganische ChemieFreie Universität BerlinFabeckstrasse 34–3614195BerlinGermany
- Lehrstuhl für Anorganische KoordinationschemieInstitut für Anorganische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
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7
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Stubbe J, Neuman NI, McLellan R, Sommer MG, Nößler M, Beerhues J, Mulvey RE, Sarkar B. Isomerisierungsreaktionen in anionischen mesoionischen Carbenboraten und Kontrolle der Eigenschaften und Reaktivität in den entstehenden Co
II
‐Komplexen durch agostische Wechselwirkungen. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202013376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Jessica Stubbe
- Institut für Chemie und Biochemie Anorganische Chemie Freie Universität Berlin Fabeckstraße 34–36 14195 Berlin Deutschland
| | - Nicolás I. Neuman
- Institut für Chemie und Biochemie Anorganische Chemie Freie Universität Berlin Fabeckstraße 34–36 14195 Berlin Deutschland
- Instituto de Desarrollo Tecnológico para la Industria Química CCT Santa Fe CONICET-UNL Colectora Ruta Nacional 168, Km 472, Paraje El Pozo 3000 Santa Fe Argentinien
| | - Ross McLellan
- WestCHEM Department of Pure & Applied Chemistry University of Strathclyde Glasgow G1 1XL Großbritannien
| | - Michael G. Sommer
- Institut für Chemie und Biochemie Anorganische Chemie Freie Universität Berlin Fabeckstraße 34–36 14195 Berlin Deutschland
| | - Maite Nößler
- Institut für Chemie und Biochemie Anorganische Chemie Freie Universität Berlin Fabeckstraße 34–36 14195 Berlin Deutschland
| | - Julia Beerhues
- Lehrstuhl für Anorganische Koordinationschemie Institut für Anorganische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Deutschland
| | - Robert E. Mulvey
- WestCHEM Department of Pure & Applied Chemistry University of Strathclyde Glasgow G1 1XL Großbritannien
| | - Biprajit Sarkar
- Institut für Chemie und Biochemie Anorganische Chemie Freie Universität Berlin Fabeckstraße 34–36 14195 Berlin Deutschland
- Lehrstuhl für Anorganische Koordinationschemie Institut für Anorganische Chemie Universität Stuttgart Pfaffenwaldring 55 70569 Stuttgart Deutschland
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8
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Martínez-Valencia B, Corona-Motolinia ND, Sánchez-Lara E, Noriega L, Sánchez-Gaytán BL, Castro ME, Meléndez-Bustamante F, González-Vergara E. Cyclo-tetravanadate bridged copper complexes as potential double bullet pro-metallodrugs for cancer treatment. J Inorg Biochem 2020; 208:111081. [PMID: 32531543 DOI: 10.1016/j.jinorgbio.2020.111081] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 03/21/2020] [Accepted: 03/21/2020] [Indexed: 02/07/2023]
Abstract
Over the last decade, copper and vanadium complexes have shown promising properties for the treatment of several types of cancer. In particular, Casiopeinas®, a group of copper-based complexes, has received specific attention, and their mechanism of action has been extensively studied since their structure is simple and their synthesis may be affordable. Similarly, vanadium-containing compounds in the form of complexes and simple polyoxovanadates have also been studied as antitumor agents. Here, potential prodrugs that would release the two metals, V and Cu, in usable form to act in conjunction against cancer cells are reported. The new series of Casiopeinas-like compounds are bridged by a cyclotetravanadate ion with the generic formula [Cu(N,N')(AA)]2•(V4O12), where (N,N') represent 1,10-phenanthroline and 2,2'-bipyridine, and (AA) are aminoacidate ions (Lysine and Ornithine). The compounds were characterized by elemental analysis, single-crystal X-ray diffraction and Visible, FTIR, and Raman spectroscopies, as well as 51V NMR, EPR, and Thermogravimetric Analysis. Additionally, theoretical calculations based on the Density Functional Theory (DFT) were carried out to model the compounds. Optimized structures, theoretical IR, and Raman spectra were also obtained, as well as docking analysis to test DNA interactions with the casiopeina-like complexes. The compounds may act as prodrugs by providing acting molecules that have showed potential pharmacological properties for the treatment of several types of cancer.
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Affiliation(s)
- Beatriz Martínez-Valencia
- Centro de Química, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, 72570 Puebla, Puebla, Mexico
| | - Nidia D Corona-Motolinia
- Centro de Química, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, 72570 Puebla, Puebla, Mexico
| | - Eduardo Sánchez-Lara
- Centro de Química, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, 72570 Puebla, Puebla, Mexico
| | - Lisset Noriega
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, 72570 Puebla, Puebla, Mexico
| | - Brenda L Sánchez-Gaytán
- Centro de Química, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, 72570 Puebla, Puebla, Mexico
| | - María Eugenia Castro
- Centro de Química, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, 72570 Puebla, Puebla, Mexico
| | | | - Enrique González-Vergara
- Centro de Química, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, 72570 Puebla, Puebla, Mexico.
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9
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Naso LG, Martínez Medina JJ, D'Alessandro F, Rey M, Rizzi A, Piro OE, Echeverría GA, Ferrer EG, Williams PAM. Ternary copper(II) complex of 5-hydroxytryptophan and 1,10-phenanthroline with several pharmacological properties and an adequate safety profile. J Inorg Biochem 2019; 204:110933. [PMID: 31825796 DOI: 10.1016/j.jinorgbio.2019.110933] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/12/2019] [Accepted: 11/17/2019] [Indexed: 12/22/2022]
Abstract
We report the synthesis and biological evaluation of a ternary copper complex, [Cu(5HTP)(phen)(H2O)](NO3).2H2O, with the antioxidant agent 5-hydroxytryptophan (5-HTP) and phenanthroline (phen, added to improve its lipophilicity and membrane transport). The crystal structure of the complex was determined by X-ray diffraction methods. The complex showed antioxidant, antimicrobial, antitumor and antimetastatic properties with an adequate safety profile. The interaction of the metal with phen promotes cellular copper accumulation and cytotoxicity on human lung A549 cell line (IC50 = 3.6 μM). Furthermore, the viability of the normal human fetal lung fibroblast cell line (MRC-5) is not altered by the complex. An oxidative stress mechanism for the anticancer effect has been determined: cellular increase of reactive oxygen species (ROS), decrease of the glutathione (GSH) and oxidized GSH (GSSG) ratio and alteration of the mitochondrial potential. The complex also displays antimetastatic activities with inhibition of cell adhesion, invasion and migration. It has not mutagenic behavior and no toxicity on Artemia salina indicating its potential to act as an effective and safety antimicrobial and antitumor drug.
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Affiliation(s)
- Luciana G Naso
- CEQUINOR, CONICET/UNLP, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Bv. 120 N° 1465, 1900 La Plata, Argentina.
| | - Juan J Martínez Medina
- Universidad Nacional del Chaco Austral, Comandante Fernández 755, CP: 3700 Presidencia Roque Sáenz Peña, Chaco, Argentina
| | - Franco D'Alessandro
- CEQUINOR, CONICET/UNLP, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Bv. 120 N° 1465, 1900 La Plata, Argentina
| | - Marilin Rey
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria-Paraje El Pozo, 3000 Santa Fe, Argentina
| | - Alberto Rizzi
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria-Paraje El Pozo, 3000 Santa Fe, Argentina
| | - Oscar E Piro
- Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y IFLP (CONICET, CCT La Plata), C.C. 67, 1900 La Plata, Argentina
| | - Gustavo A Echeverría
- Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y IFLP (CONICET, CCT La Plata), C.C. 67, 1900 La Plata, Argentina
| | - Evelina G Ferrer
- CEQUINOR, CONICET/UNLP, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Bv. 120 N° 1465, 1900 La Plata, Argentina
| | - Patricia A M Williams
- CEQUINOR, CONICET/UNLP, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Bv. 120 N° 1465, 1900 La Plata, Argentina.
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10
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Synthesis, structural elucidation and antiradical activity of a copper (II) naringenin complex. Biometals 2019; 32:595-610. [DOI: 10.1007/s10534-019-00187-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 03/09/2019] [Indexed: 10/27/2022]
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11
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Martínez Medina JJ, Naso LG, Pérez AL, Rizzi A, Okulik NB, Valcarcel M, Salado C, Ferrer EG, Williams PAM. Synthesis, characterization, theoretical studies and biological (antioxidant, anticancer, toxicity and neuroprotective) determinations of a copper(II) complex with 5-hydroxytryptophan. Biomed Pharmacother 2018; 111:414-426. [PMID: 30594780 DOI: 10.1016/j.biopha.2018.12.098] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 12/18/2018] [Accepted: 12/19/2018] [Indexed: 10/27/2022] Open
Abstract
5-Hydroxy-L-tryptophan (5-HTP) is a serotonin pathway metabolite of L-tryptophan in the brain. In the knowledge that the biological properties of some compounds can be modified upon metal complexation, a new solid metal complex, [Cu(5-hydroxytryptophan)2].H2O (Cu5HTP), has been synthesized and characterized to analyze the modification of some biological properties. The conformational investigations (optimized in gas phase at B3LYP/6-311G** theory level) suggest the coexistence of two conformers of Cu5HTP with cis- and trans- arrangements of the amino acids in the equatorial plane. The trans- Cu5HTP1 complex is the most stable conformer. The complexation led to an enhancement of the antioxidant properties of the ligand. The metal complex also improved the anticancer behavior of the ligand (tested in cancer cell lines derived from human lung (A549), cervix (HeLa) and colon (HCT-116)). It did not show toxicity against either the non-malignant human lung fibroblast (MRC-5) cell line or Artemia salina and did not behave as mutagenic agent (Ames test). Cellular reactive oxygen species production may be one of the possible mechanisms of action. Besides, the metal complex exerted neuroprotective action on cortical neurons from embryonic 18 days rats exposed to glutamate.
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Affiliation(s)
- Juan J Martínez Medina
- Universidad Nacional del Chaco Austral, Comandante Fernández, 755 - CP: 3700, Presidencia Roque Sáenz Peña, Chaco, Argentina
| | - Luciana G Naso
- CEQUINOR, CONICET/CICPBA/UNLP, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Bv. 120 Nº 1465, 1900 La Plata, Argentina
| | - Ana L Pérez
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria-Paraje El Pozo, 3000 Santa Fe, Argentina
| | - Alberto Rizzi
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria-Paraje El Pozo, 3000 Santa Fe, Argentina
| | - Nora B Okulik
- Universidad Nacional del Chaco Austral, Comandante Fernández, 755 - CP: 3700, Presidencia Roque Sáenz Peña, Chaco, Argentina
| | - María Valcarcel
- Innoprot SL, Edificio 502-P1- Parque Tecnológico, 48160, Derio, Spain
| | - Clarisa Salado
- Innoprot SL, Edificio 502-P1- Parque Tecnológico, 48160, Derio, Spain
| | - Evelina G Ferrer
- CEQUINOR, CONICET/CICPBA/UNLP, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Bv. 120 Nº 1465, 1900 La Plata, Argentina
| | - Patricia A M Williams
- CEQUINOR, CONICET/CICPBA/UNLP, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Bv. 120 Nº 1465, 1900 La Plata, Argentina.
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12
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Pérez AL, Kemmerer A, Rey MA, Dalosto SD, Ramos CA, Passeggi MCG, Rizzi AC, Brondino CD. Coupled High Spin Co
II
Ions Linked by Symmetrical Double Hydrogen Bonds: Role of a Slowly Relaxing Cu
II
Impurity in Interrupting the Co
II
–Co
II
Exchange Interaction. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ana L. Pérez
- Departamento de Física Facultad de Bioquímica y Ciencias Biológicas Universidad Nacional del Litoral ‐ CONICET Ciudad Universitaria S3000ZAA Santa Fe Argentina
| | - Axel Kemmerer
- Departamento de Física Facultad de Bioquímica y Ciencias Biológicas Universidad Nacional del Litoral ‐ CONICET Ciudad Universitaria S3000ZAA Santa Fe Argentina
| | - Marilin A. Rey
- Departamento de Física Facultad de Bioquímica y Ciencias Biológicas Universidad Nacional del Litoral ‐ CONICET Ciudad Universitaria S3000ZAA Santa Fe Argentina
| | - Sergio D. Dalosto
- Instituto de Física del Litoral Universidad Nacional del Litoral ‐ CONICET Güemes 3450 3000 Santa Fe Argentina
| | - Carlos A. Ramos
- Centro Atómico Bariloche Comisión Nacional de Energía Atómica Av. Bustillo 9500 8400 Bariloche Río Negro Argentina
| | - Mario C. G. Passeggi
- Departamento de Física Facultad de Bioquímica y Ciencias Biológicas Universidad Nacional del Litoral ‐ CONICET Ciudad Universitaria S3000ZAA Santa Fe Argentina
- Instituto de Física del Litoral Universidad Nacional del Litoral ‐ CONICET Güemes 3450 3000 Santa Fe Argentina
| | - Alberto C. Rizzi
- Departamento de Física Facultad de Bioquímica y Ciencias Biológicas Universidad Nacional del Litoral ‐ CONICET Ciudad Universitaria S3000ZAA Santa Fe Argentina
| | - Carlos D. Brondino
- Departamento de Física Facultad de Bioquímica y Ciencias Biológicas Universidad Nacional del Litoral ‐ CONICET Ciudad Universitaria S3000ZAA Santa Fe Argentina
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13
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Golovnev NN, Molokeev MS, Sterkhova IV, Lesnikov MK. Two novel mixed-ligand Ni(II) and Co(II) complexes with 1,10-phenanthroline: Synthesis, structural characterization, and thermal stability. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.07.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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14
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Žilić D, Maity D, Cetina M, Molčanov K, Džolić Z, Herak M. Magnetostructural Characterization of Oxalamide Dihalo-Bridged Copper Dimers: Intra- and Interdimer Interactions Studied by Single-Crystal Electron Spin Resonance Spectroscopy. Chemphyschem 2017. [PMID: 28636148 DOI: 10.1002/cphc.201700433] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Detailed single-crystal electron spin resonance (ESR) analysis of oxalamide complexes with halogen-bridged copper dimers, supported by X-ray, magnetic susceptibility, and powder ESR studies, is reported. Four complexes with two different ligands are synthesized: [CuLA (μ-X)]2 and [CuLV (μ-X)]2 , for which LA =N-(l-alanine methyl ester)-N'-[(2-pyridine-2-yl)methyl]oxalamide and LV =N-(l-valine methyl ester)-N'-[(2-pyridine-2-yl)methyl]oxalamide, for which X=Cl or Br. X-ray analysis shows that the geometry at each copper(II) ion is square pyramidal, whereas two pyramids share one base-to-apex edge with parallel basal planes. The complexes are linked by hydrogen bonds into infinite chains and are further linked into a 3D network. Susceptibility measurements show that the copper centers in the dimers are weakly antiferromagnetically coupled (|J|≈1-2 cm-1 ). From powder ESR spectroscopy, the g values and dx2-y2 orbital as the ground state of the unpaired electron are determined. The complexes show unusual anisotropic splitting and merging of the ESR lines if their single crystals rotate in a magnetic field. The observation of this partially resolved intradimer dipolar splitting enables estimation of the weak interdimer exchange interaction parameter |J'|≈0.001 cm-1 .
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Affiliation(s)
- Dijana Žilić
- Ruđer Bošković Institute, Bijenička c. 54, HR-10000, Croatia
| | - Debdeep Maity
- Ruđer Bošković Institute, Bijenička c. 54, HR-10000, Croatia
| | - Mario Cetina
- Department of Applied Chemistry, Faculty of Textile Technology, University of Zagreb, Prilaz baruna Filipovića 28a, HR-10000, Zagreb, Croatia
| | | | - Zoran Džolić
- Ruđer Bošković Institute, Bijenička c. 54, HR-10000, Croatia
| | - Mirta Herak
- Institute of Physics, Bijenička c. 46, HR-10000, Zagreb, Croatia
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15
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Exchange interaction between S= 1/2 centers bridged by multiple noncovalent interactions: Contribution of the individual chemical pathways to the magnetic coupling. Polyhedron 2017. [DOI: 10.1016/j.poly.2016.12.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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16
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Lada ZG, Sanakis Y, Raptopoulou CP, Psycharis V, Perlepes SP, Mitrikas G. Probing the electronic structure of a copper(ii) complex by CW- and pulse-EPR spectroscopy. Dalton Trans 2017. [DOI: 10.1039/c7dt01785e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The electronic structure of a mononuclear octahedral copper(ii) complex has been studied using CW EPR spectroscopy and other advanced methods including Davies ENDOR and HYSCORE (1H and 13C) spectroscopy.
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Affiliation(s)
- Zoi G. Lada
- Foundation for Research and Technology-Hellas (FORTH)
- Institute of Chemical Engineering Sciences (ICE-HT)
- 26504 Patras
- Greece
- Department of Chemistry
| | - Yiannis Sanakis
- Institute of Nanoscience and Nanotechnology
- NCSR “Demokritos”
- 153 10 Aghia Paraskevi Attikis
- Greece
| | - Catherine P. Raptopoulou
- Institute of Nanoscience and Nanotechnology
- NCSR “Demokritos”
- 153 10 Aghia Paraskevi Attikis
- Greece
| | - Vassilis Psycharis
- Institute of Nanoscience and Nanotechnology
- NCSR “Demokritos”
- 153 10 Aghia Paraskevi Attikis
- Greece
| | - Spyros P. Perlepes
- Foundation for Research and Technology-Hellas (FORTH)
- Institute of Chemical Engineering Sciences (ICE-HT)
- 26504 Patras
- Greece
- Department of Chemistry
| | - George Mitrikas
- Institute of Nanoscience and Nanotechnology
- NCSR “Demokritos”
- 153 10 Aghia Paraskevi Attikis
- Greece
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17
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Structural Diversity, Electrochemical, and DNA-Binding Properties of Copper(II) Carboxylates. IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY TRANSACTION A-SCIENCE 2016. [DOI: 10.1007/s40995-016-0141-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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18
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Ng CH, Wang WS, Win YF, Neo KE, Ganguly R, Er HM, Ooi IH. Rac-aqua(4-methyl-oxazolidine-4-carboxylato)(nitrato)(1,10-phenanthroline)copper(II), the aldol condensation product of formaldehyde with the d- and l-(alaninato)aqua(1,10-phenanthroline)copper(II) nitrate. TRANSIT METAL CHEM 2016. [DOI: 10.1007/s11243-016-0053-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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19
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Rizzi AC, Neuman NI, González PJ, Brondino CD. EPR as a Tool for Study of Isolated and Coupled Paramagnetic Centers in Coordination Compounds and Macromolecules of Biological Interest. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201501111] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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20
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Morellato N, Musetti C, Palumbo M, Dolmella A, Bolzati C, Sissi C. Biologically relevant Cu2+ complexes with a tridentate phenanthroline analogue: Structural properties and DNA damage. Inorganica Chim Acta 2015. [DOI: 10.1016/j.ica.2015.04.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Neuman NI, Burna E, Baggio R, Passeggi MCG, Rizzi AC, Brondino CD. Transition from isolated to interacting copper(ii) pairs in extended lattices evaluated by single crystal EPR spectroscopy. Inorg Chem Front 2015. [DOI: 10.1039/c5qi00086f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Single crystal EPR experiments in copper-doped dimeric Zn(tda)(phen) allowed determination of Cu(ii) g- and A-matrices and ZFS parameters, which are used to evaluate the interdimeric exchange interaction in pure Cu(tda)(phen).
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Affiliation(s)
- Nicolás I. Neuman
- Departamento de Física
- Facultad de Bioquímica y Ciencias Biológicas
- Universidad Nacional del Litoral
- S3000ZAA Santa Fe
- Argentina
| | - Emerson Burna
- Departamento de Física
- Facultad de Bioquímica y Ciencias Biológicas
- Universidad Nacional del Litoral
- S3000ZAA Santa Fe
- Argentina
| | - Ricardo Baggio
- Gerencia de Investigación y Aplicaciones
- Comisión Nacional de Energía Atómica
- Avenida Gral Paz y Constituyentes
- San Martín
- Argentina
| | - Mario C. G. Passeggi
- Departamento de Física
- Facultad de Bioquímica y Ciencias Biológicas
- Universidad Nacional del Litoral
- S3000ZAA Santa Fe
- Argentina
| | - Alberto C. Rizzi
- Departamento de Física
- Facultad de Bioquímica y Ciencias Biológicas
- Universidad Nacional del Litoral
- S3000ZAA Santa Fe
- Argentina
| | - Carlos D. Brondino
- Departamento de Física
- Facultad de Bioquímica y Ciencias Biológicas
- Universidad Nacional del Litoral
- S3000ZAA Santa Fe
- Argentina
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22
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Chang YH, Leu WJ, Datta A, Hsiao HC, Lin CH, Guh JH, Huang JH. Catalytic transfer hydrogenation and anticancer activity of arene–ruthenium compounds incorporating bi-dentate precursors. Dalton Trans 2015; 44:16107-18. [DOI: 10.1039/c5dt01310k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of arene–Ru compounds were synthesized and their catalytic transfer hydrogenation and anticancer activity towards human hormone-refractory prostate cancer were investigated.
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Affiliation(s)
- Yu-Hsiang Chang
- Department of Chemistry
- National Changhua University of Education
- Changhua
- Taiwan 50058
| | - Wohn-Jenn Leu
- School of Pharmacy
- National Taiwan University
- Taipei
- Taiwan 100
| | - Amitabha Datta
- Department of Chemistry
- National Changhua University of Education
- Changhua
- Taiwan 50058
| | - Hung-Chang Hsiao
- Department of Chemistry
- National Changhua University of Education
- Changhua
- Taiwan 50058
| | - Chia-Her Lin
- Department of Chemistry
- Chung-Yuan Christian University
- Chun-Li 320
- Taiwan
| | - Jih-Hwa Guh
- School of Pharmacy
- National Taiwan University
- Taipei
- Taiwan 100
| | - Jui-Hsien Huang
- Department of Chemistry
- National Changhua University of Education
- Changhua
- Taiwan 50058
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23
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Neuman NI, Winkler E, Peña O, Passeggi MCG, Rizzi AC, Brondino CD. Magnetic properties of weakly exchange-coupled high spin Co(II) ions in pseudooctahedral coordination evaluated by single crystal X-band EPR spectroscopy and magnetic measurements. Inorg Chem 2014; 53:2535-44. [PMID: 24528370 DOI: 10.1021/ic402797t] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We report single-crystal X-band EPR and magnetic measurements of the coordination polymer catena-(trans-(μ2-fumarato)tetraaquacobalt(II)), 1, and the Co(II)-doped Zn(II) analogue, 2, in different Zn:Co ratios. 1 presents two magnetically inequivalent high spin S = 3/2 Co(II) ions per unit cell, named A and B, in a distorted octahedral environment coordinated to four water oxygen atoms and trans coordinated to two carboxylic oxygen atoms from the fumarate anions, in which the Co(II) ions are linked by hydrogen bonds and fumarate molecules. Magnetic susceptibility and magnetization measurements of 1 indicate weak antiferromagnetic exchange interactions between the S = 3/2 spins of the Co(II) ions in the crystal lattice. Oriented single crystal EPR experiments of 1 and 2 were used to evaluate the molecular g-tensor and the different exchange coupling constants between the Co(II) ions, assuming an effective spin S′= 1/2. Unexpectedly, the eigenvectors of the molecular g-tensor were not lying along any preferential bond direction, indicating that, in high spin Co(II) ions in roughly octahedral geometry with approximately axial EPR signals, the presence of molecular pseudo axes in the metal site does not determine preferential directions for the molecular g-tensor. The EPR experiment and magnetic measurements, together with a theoretical analysis relating the coupling constants obtained from both techniques, allowed us to evaluate selectively the exchange coupling constant associated with hydrogen bonds that connect magnetically inequivalent Co(II) ions (|JAB(1/2)| = 0.055(2) cm(–1)) and the exchange coupling constant associated with a fumarate bridge connecting equivalent Co(II) ions (|JAA(1/2)| ≈ 0.25 (1) cm(–1)), in good agreement with the average J(3/2) value determined from magnetic measurements.
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Affiliation(s)
- Nicolás I Neuman
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral , S3000ZAA Santa Fe, Argentina
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24
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Electron paramagnetic resonance study of ternary CuII compounds with glycine and phenanthroline. J CHEM SCI 2014. [DOI: 10.1007/s12039-013-0553-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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25
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Allão Cassaro RA, Baskett M, Lahti PM. An electron paramagnetic resonance study of spin site variations in Cu(hfac)2 complexes with 5-(3-N-tert-butyl-N-aminoxylphenyl)pyrimidine. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.04.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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