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Pissas M, Ferentinos E, Kyritsis P, Sanakis Y. Field-Induced Slow Magnetization Relaxation of a Tetrahedral S=2 Fe IIS 4-Containing Complex. Chempluschem 2024:e202400109. [PMID: 38727531 DOI: 10.1002/cplu.202400109] [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: 02/06/2024] [Revised: 05/08/2024] [Indexed: 06/09/2024]
Abstract
In the work described herein, the spin relaxation properties of the mononuclear tetrahedral S=2 [Fe{(SPiPr2)2N}2] complex (1) were studied by employing static and dynamic magnetic measurements at liquid helium temperatures. In the absence of an external direct current (DC) magnetic field, 1 exhibits fast magnetization relaxation. However, in the presence of external magnetic fields of a few kOe, slow relaxation is induced as monitored by alternating current (AC) magnetic susceptibility measurements up to 10 kHz, in the temperature range 2-5 K. Analysis of the temperature dependence of the corresponding relaxation time reveals contributions by Quantum Tunnelling of Magnetization, and the Direct and Orbach processes in the magnetization relaxation mechanism of 1. The energy barrier, Ueff, of the Orbach process, as determined by this analysis, is compared with that related to the zero-field splitting parameters of 1 which were previously determined by high- frequency and -field electron paramagnetic resonance and Mössbauer spectroscopies.
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Affiliation(s)
- Michael Pissas
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, 15341, Ag. Paraskevi, Attiki, Greece
| | - Eleftherios Ferentinos
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, 15571, Athens, Greece
| | - Panayotis Kyritsis
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, 15571, Athens, Greece
| | - Yiannis Sanakis
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, 15341, Ag. Paraskevi, Attiki, Greece
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2
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Eslami F, Pourayoubi M, Sabbaghi F, Skořepová E, Dušek M, Baniyaghoob S. Diastereotopic groups in two new single-enanti-omer structures ( R2)P(O)[NH-(+)CH(C 2H 5)(C 6H 5)] ( R = OC 6H 5 and C 6H 5). Acta Crystallogr E Crystallogr Commun 2023; 79:769-776. [PMID: 37693677 PMCID: PMC10483558 DOI: 10.1107/s2056989023006278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 07/19/2023] [Indexed: 09/12/2023]
Abstract
The crystal structures of two single-enanti-omer compounds, i.e. diphenyl [(R)-(+)-α-ethyl-benzyl-amido]-phosphate, C21H22NO3P or (C6H5O)2P(O)[NH-(R)-(+)CH(C2H5)(C6H5)] (I), and N-[(R)-(+)-α-ethyl-benz-yl]-P,P-di-phenyl-phosphinic amide, C21H22NOP or (C6H5)2P(O)[NH-R-(+)CH(C2H5)(C6H5)] (II), were studied. The different environments at the phospho-rus atoms, (O)2P(O)(N) and (C)2P(O)(N), allow the P=O/P-N bond strengths to be compared, as well as the N-H⋯O=P hydrogen-bond strengths, and P=O/N-H vibrations. The following characteristics related to diastereotopic C6H5O/C6H5 groups in I/II were considered: geometry parameters, contributions to the crystal packing, solution 13C/1H NMR chemical shifts, conformations, and NMR coupling constants. The phospho-rus-carbon coupling constants nJ PC (n = 2 and 3) in I and mJ PC (m = 1, 2, 3 and 4) in II were evaluated. For a comparative study, chiral analogous structures were retrieved from the Cambridge Structural Database (CSD) and their geometries and conformations are discussed.
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Affiliation(s)
- Farnaz Eslami
- Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Mehrdad Pourayoubi
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Fahimeh Sabbaghi
- Department of Chemistry, Zanjan Branch, Islamic Azad University, Zanjan, Iran
| | - Eliška Skořepová
- Institute of Physics of the Czech Academy of Sciences, Na Slovance 2, 182 21, Prague 8, Czech Republic
| | - Michal Dušek
- Institute of Physics of the Czech Academy of Sciences, Na Slovance 2, 182 21, Prague 8, Czech Republic
| | - Sahar Baniyaghoob
- Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran
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3
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Zhou Y, Moorthy S, Wei XQ, Singh SK, Tian Z, Shao D. A porous cobalt(II)-organic framework exhibiting high room temperature proton conductivity and field-induced slow magnetic relaxation. Dalton Trans 2023; 52:909-918. [PMID: 36594631 DOI: 10.1039/d2dt03383f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A two-dimensional (2D) cobalt(II) metal-organic framework (MOF) constructed by a ditopic organic ligand, formulated as {[Co(Hbic)(H2O)]·4H2O}n (1) (H2bic = 1H-benzimidazole-5-carboxylic acid), was hydrothermally synthesized and structurally characterized. Single-crystal X-ray diffraction shows that the distorted octahedral Co2+ ions, as coordination nodes, are bridged to form 2D honeycomb networks, which are further organized into a 3D supramolecular porous framework through multiple hydrogen bonds and interlayer π-π interactions. Dynamic crystallography experiments reveal the anisotropic thermal expansion behavior of the lattice, suggesting a flexible hydrogen-bonded 3D framework. Interestingly, hydrogen-bonded (H2O)4 tetramers were found to be located in porous channels, yielding 1D proton transport pathways. As a result, the compound exhibited a high room-temperature proton conductivity of 1.6 × 10-4 S cm-1 under a relative humidity of 95% through a Grotthuss mechanism. Magnetic investigations combined with theoretical calculations reveal giant easy-plane magnetic anisotropy of the distorted octahedral Co2+ ions with the experimental and computed D values being 87.1 and 109.3 cm-1, respectively. In addition, the compound exhibits field-induced slow magnetic relaxation behavior at low temperatures with an effective energy barrier of Ueff = 45.2 cm-1. Thus, the observed electrical and magnetic properties indicate a rare proton conducting SIM-MOF. The foregoing results provide a unique bifunctional cobalt(II) framework material and suggest a promising way to achieve magnetic and electrical properties using a supramolecular framework platform.
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Affiliation(s)
- Yue Zhou
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China.
| | - Shruti Moorthy
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi-502285, Sangareddy, Telangana, India
| | - Xiao-Qin Wei
- Department of Material Science and Engineering, Shanxi Province Collaborative Innovation Center for Light Materials Modification and Application, Jinzhong University, Jinzhong, 030619, P. R. China
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi-502285, Sangareddy, Telangana, India
| | - Zhengfang Tian
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China.
| | - Dong Shao
- Hubei Key Laboratory of Processing and Application of Catalytic Materials, College of Chemistry and Chemical Engineering, Huanggang Normal University, Huanggang 438000, P. R. China. .,State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing, 210023, P. R. China
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4
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Charytanowicz T, Jankowski R, Zychowicz M, Chorazy S, Sieklucka B. The rationalized pathway from field-induced slow magnetic relaxation in CoII–WIV chains to single-chain magnetism in isotopological CoII–WV analogues. Inorg Chem Front 2022. [DOI: 10.1039/d1qi01427g] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The change of the oxidation state from WIV to WV in isotopological CoII–[W(CN)8]n− chains leads to the appearence of pronounced single-chain magnet behaviour.
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Affiliation(s)
- Tomasz Charytanowicz
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Robert Jankowski
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Mikolaj Zychowicz
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Szymon Chorazy
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Barbara Sieklucka
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
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Korchagin DV, Gureev YE, Yureva EA, Shilov GV, Akimov AV, Misochko EY, Morgunov RB, Zakharov KV, Vasiliev AN, Palii AV, Lohmiller T, Holldack K, Aldoshin SM. Field-induced single-ion magnet based on a quasi-octahedral Co(II) complex with mixed sulfur-oxygen coordination environment. Dalton Trans 2021; 50:13815-13822. [PMID: 34519734 DOI: 10.1039/d1dt02413b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthesis and characterization of structure and magnetic properties of the quasi-octahedral complex (pipH2)[Co(TDA)2] 2H2O (I), (pipH22+ = piperazine dication, TDA2- = thiodiacetic anion) are described. X-ray diffraction studies reveal the first coordination sphere of the Co(II) ion, consisting of two chelating tridentate TDA ligands with a mixed sulfur-oxygen strongly elongated octahedral coordination environment. SQUID magnetometry, frequency-domain Fourier-transform (FD-FT) THz-EPR spectroscopy, and high-level ab initio SA-CASSCF/NEVPT2 quantum chemical calculations reveal a strong "easy-plane" type magnetic anisotropy (D ≈ +54 cm-1) of complex I. The complex shows field-induced slow relaxation of magnetization at an applied DC field of 1000 Oe.
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Affiliation(s)
- D V Korchagin
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - Ya E Gureev
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432. .,M.V. Lomonosov Moscow State University, Moscow 119991, Russia
| | - E A Yureva
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - G V Shilov
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - A V Akimov
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - E Ya Misochko
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - R B Morgunov
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
| | - K V Zakharov
- M.V. Lomonosov Moscow State University, Moscow 119991, Russia
| | - A N Vasiliev
- M.V. Lomonosov Moscow State University, Moscow 119991, Russia.,National University of Science and Technology "MISiS", Moscow, 119049, Russia
| | - A V Palii
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432. .,Institute of Applied Physics, Academy of Sciences of Moldova, Kishinev, Moldova
| | - T Lohmiller
- EPR4Energy Joint Lab, Department Spins in Energy Conversion and Quantum Information Science, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
| | - K Holldack
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, 12489 Berlin, Germany
| | - S M Aldoshin
- Institute of Problems of Chemical Physics, Russian Academy of Sciences, 1, Acad. Semenov Av., Chernogolovka, Russian Federation, 142432.
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Nano K, Zahariou G, Ioannou PC, Alam MM, Pantazis DA, Raptopoulou CP, Psycharis V, Sanakis Y, Kyritsis P. Electronic properties of the S = 5/2 Mn(II) complexes [Mn{PhC(O)NP(O)PPh2}(N,N)(NO3)], (N,N) = phenanthroline, neocuproine, 2,2′-bipyridine. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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7
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Bhowmick I, Newell BS, Shores MP. A systematic study of the influence of ligand field on the slow magnetic dynamics of Co(ii)-diimine compounds. Dalton Trans 2021; 50:10737-10748. [PMID: 34269774 DOI: 10.1039/d0dt01597k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein we report heteroleptic Co(ii) diimine complexes [Co(H2bip)2Cl2] (1), [Co(H2bip)2Br2] (2), [Co(H2bip)3]Br2·1MeOH (3) and [Co(H2bip)2(Me2bpy)]Br2·(MeCN)0.5·(H2O)0.25 (4) (H2bip = 2,2'-bi-1,4,5,6-tetrahydropyrimidine, bpy = 2,2'-dipyridyl, Me2bpy = 4,4'-Me-2,2'-dipyridyl), purposefully prepared to enable a systematic study of magnetic property changes arising from the increase of overall ligand field from σ/π-donor chlorido (1) to π-acceptor 4,4'Me-2,2'bpy (4). The presence of axial and rhombic anisotropy (D and E) of these compounds is sufficient to allow 1-4 to show field-induced slow relaxation of magnetization. Interestingly, we found as the effective ligand field is increased in the series, rhombicity (E/D) decreases, and the magnetic relaxation profile changes significantly, where relaxation of magnetization at a specific temperature becomes gradually faster. We performed mechanistic analyses of the temperature dependence of magnetic relaxation times considering Orbach relaxation processes, Raman-like relaxation and quantum tunnelling of magnetization (QTM). The effective energy barrier of the Orbach relaxation process (Ueff) is largest in compound 1 (19.2 cm-1) and gradually decreases in the order 1 > 2 > 3 > 4 giving a minimum value in compound 4 (8.3 cm-1), where the Raman-like mechanism showed the possibility of different types of phonon activity below and above ∼2.5 K. As a precursor of 1, the tetrahedral complex [Co(H2bip)Cl2] (1a) was also synthesized and structurally and magnetically characterized: this compound exhibits slow relaxation of magnetization under an applied dc field (1800 Oe) with a record slow relaxation time of 3.39 s at 1.8 K.
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Affiliation(s)
- Indrani Bhowmick
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA.
| | - Brian S Newell
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA. and Analytical Resources Core, Center for Materials and Molecular Analysis, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Matthew P Shores
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA.
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A Molecular Tetrahedral Cobalt-Seleno-Based Complex as an Efficient Electrocatalyst for Water Splitting. Molecules 2021; 26:molecules26040945. [PMID: 33579044 PMCID: PMC7916788 DOI: 10.3390/molecules26040945] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/01/2021] [Accepted: 02/04/2021] [Indexed: 11/17/2022] Open
Abstract
The cobalt-seleno-based coordination complex, [Co{(SePiPr2)2N}2], is reported with respect to its catalytic activity in oxygen evolution and hydrogen evolution reactions (OER and HER, respectively) in alkaline solutions. An overpotential of 320 and 630 mV was required to achieve 10 mA cm-2 for OER and HER, respectively. The overpotential for OER of this CoSe4-containing complex is one of the lowest that has been observed until now for molecular cobalt(II) systems, under the reported conditions. In addition, this cobalt-seleno-based complex exhibits a high mass activity (14.15 A g-1) and a much higher turn-over frequency (TOF) value (0.032 s-1) at an overpotential of 300 mV. These observations confirm analogous ones already reported in the literature pertaining to the potential of molecular cobalt-seleno systems as efficient OER electrocatalysts.
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