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Bernbeck M, Orlova AP, Hilgar JD, Gembicky M, Ozerov M, Rinehart JD. Dipolar Coupling as a Mechanism for Fine Control of Magnetic States in ErCOT-Alkyl Molecular Magnets. J Am Chem Soc 2024; 146:7243-7256. [PMID: 38456803 PMCID: PMC10958522 DOI: 10.1021/jacs.3c10412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 02/13/2024] [Accepted: 02/14/2024] [Indexed: 03/09/2024]
Abstract
The design of molecular magnets has progressed greatly by taking advantage of the ability to impart successive perturbations and control vibronic transitions in 4fn systems through the careful manipulation of the crystal field. Herein, we control the orientation and rigidity of two dinuclear ErCOT-based molecular magnets: the inversion-symmetric bridged [ErCOT(μ-Me)(THF)]2 (2) and the nearly linear Li[(ErCOT)2(μ-Me)3] (3). The conserved anisotropy of the ErCOT synthetic unit facilitates the direction of the arrangement of its magnetic anisotropy for the purposes of generating controlled internal magnetic fields, improving control of the energetics and transition probabilities of the electronic angular momentum states with exchange biasing via dipolar coupling. This control is evidenced through the introduction of a second thermal barrier to relaxation operant at low temperatures that is twice as large in 3 as in 2. This barrier acts to suppress through-barrier relaxation by protecting the ground state from interacting with stray local fields while operating at an energy scale an order of magnitude smaller than the crystal field term. These properties are highlighted when contrasted against the mononuclear structure ErCOT(Bn)(THF)2 (1), in which quantum tunneling of the magnetization processes dominate, as demonstrated by magnetometry and ab initio computational methods. Furthermore, far-infrared magnetospectroscopy measurements reveal that the increased rigidity imparted by successive removal of solvent ligands when adding bridging methyl groups, along with the increased excited state purity, severely limits local spin-vibrational interactions that facilitate magnetic relaxation, manifesting as longer relaxation times in 3 relative to those in 2 as temperature is increased.
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Affiliation(s)
- Maximilian
G. Bernbeck
- Department
of Chemistry and Biochemistry, University
of California—San Diego, La Jolla, California 92093, United States
| | - Angelica P. Orlova
- Department
of Chemistry and Biochemistry, University
of California—San Diego, La Jolla, California 92093, United States
| | - Jeremy D. Hilgar
- Department
of Chemistry and Biochemistry, University
of California—San Diego, La Jolla, California 92093, United States
| | - Milan Gembicky
- Department
of Chemistry and Biochemistry, University
of California—San Diego, La Jolla, California 92093, United States
| | - Mykhaylo Ozerov
- National
High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Jeffrey D. Rinehart
- Department
of Chemistry and Biochemistry, University
of California—San Diego, La Jolla, California 92093, United States
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2
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Abdallah AM, Zaki NG, Mahmoud WH, El Kerdawy AM, Mohamed GG. Synthesis, structural characterization, density functional theory calculations, and antimicrobial, anticancer, and antimetastatic properties of nanosized heteroleptic complexes of cocaine/TMEDA with d‐block metal ions. Appl Organomet Chem 2021. [DOI: 10.1002/aoc.6441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Affiliation(s)
- Abanoub Mosaad Abdallah
- Narcotic Research Department National Center for Social and Criminological Research (NCSCR) Giza Egypt
| | - Nadia G. Zaki
- Narcotic Research Department National Center for Social and Criminological Research (NCSCR) Giza Egypt
| | - Walaa H. Mahmoud
- Chemistry Department, Faculty of Science Cairo University Giza Egypt
| | - Ahmed M. El Kerdawy
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy Cairo University Cairo Egypt
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy New Giza University Cairo Egypt
| | - Gehad G. Mohamed
- Chemistry Department, Faculty of Science Cairo University Giza Egypt
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3
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Shurygin AV, Vovna VI, Korochentsev VV, Mirochnik AG, Kalinovskaya IV, Sergienko VI. Optical properties and electronic structure of Eu(III) complexes with HMPA and TPPO. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 250:119397. [PMID: 33422875 DOI: 10.1016/j.saa.2020.119397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/01/2020] [Accepted: 12/26/2020] [Indexed: 06/12/2023]
Abstract
Two adducts of Eu(III) tris-hexofluoroacetylacetonate with HMPA (OP(N(CH3)2)3, hexamethylphosphotriamide) and TPPO (OP(C6H5)3, triphenylphosphine oxide) were studied by optical spectroscopy and quantum chemistry (DFT/TD-DFT). The structure of the higher occupied molecular orbitals (MO) of the two adducts determines differences in the position of the excitation band maximum of hfac ligands. According to the calculation data, all excited states are caused by the transition to 3 vacant π4* MOs of hfac ligands. Optical spectra of absorption, excitation and luminescence are obtained and interpreted. The peculiarity of the HOMO-LUMO structure, the low value of the energy gap, and the broadened absorption region of hfac ligands compensate the low absorbance ability of the groups N(CH3)2 in a region of 220-360 nm for the adduct Eu(hfac)3(HMPA)2, reducing the luminescence intensity by only 5-10% relative to the adduct of the Eu(III) complex with TPPO ligands.
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Affiliation(s)
- A V Shurygin
- Far Eastern Federal University, 8 Sukhanova St., Vladivostok, Russia
| | - V I Vovna
- Far Eastern Federal University, 8 Sukhanova St., Vladivostok, Russia.
| | - V V Korochentsev
- Far Eastern Federal University, 8 Sukhanova St., Vladivostok, Russia
| | - A G Mirochnik
- Institute of Chemistry, FEB RAS, 159 Prosp. 100-letiya Vladivostoka, Vladivostok, Russia
| | - I V Kalinovskaya
- Institute of Chemistry, FEB RAS, 159 Prosp. 100-letiya Vladivostoka, Vladivostok, Russia
| | - V I Sergienko
- Far Eastern Branch, RAS, 50 Svetlanskaya St., Vladivostok, Russia
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Evans KJ, Morton PA, Sangster C, Mansell SM. One-step synthesis of heteroleptic rare-earth amide complexes featuring fluorenyl-tethered N-heterocyclic carbene ligands. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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5
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Zaki NG, Mahmoud WH, El Kerdawy AM, Abdallah AM, Mohamed GG. Heteroleptic complexes of cocaine/TMEDA with some f block metals: Synthesis, DFT studies, spectral, thermal, cytotoxicity and antimetastatic properties. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 229:117938. [PMID: 31841673 DOI: 10.1016/j.saa.2019.117938] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/29/2019] [Accepted: 12/07/2019] [Indexed: 06/10/2023]
Abstract
A series of new three heteroleptic complexes of the general formula [Ln(Cn)(TMEDA)Cl(OH2)]·2Cl·xH2O, (where Ln = La(III), Er(III) and Yb(III), Cn = cocaine and TMEDA = N,N,N',N'-tetramethylethylenediamine) were synthesized, structurally characterized by elemental analysis, spectroscopic methods, molar conductivity and mass spectrometry. Thermal properties of the synthesized complexes and their kinetic thermodynamic parameters were studied. Theoretical calculations including geometry optimization, electronic structure and electronic and thermal energies were carried out using DFT and TD-DFT calculations at B3LYP/LANL2DZ level of theory and the different quantum chemical parameters were calculated. The in vitro antiproliferative activity of the newly synthesized complexes was assessed by MTT assay on MCF-7 and HepG-2 cancer cell lines. Yb(III) complex showed promising cytotoxic activity comparable to that of cisplatin on both cell lines with minimum effect on human normal cells. Further molecular mechanistic investigations showed that Yb(III) complex is an apoptotic inducer as it raises the caspase-3 and caspase-9 cellular level in the MCF-7 cell line. Furthermore, it showed an elevating effect on the level of the tumor suppressor nuclear proteins P21 and P27 concentrations in MCF-7 cells. Moreover, Yb(III) complex hindered the cellular scavenger system of the reactive oxygen species through reducing the glutathione peroxidase (GPx) cellular level imperiling MCF-7 cells by unmanageable oxidative stress. In addition to its cytotoxic effect, Yb(III) complex showed antimetastatic properties as it decreased the cellular levels of matrix metalloproteinases MMP-3 and MMP-9. These results showed that the Yb(III) complex is a promising cytotoxic metal-based agent that exerts its action through various molecular mechanisms with minimum effects on normal cells and with additional antimetastatic properties.
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Affiliation(s)
- Nadia G Zaki
- Narcotic Research Department, National Center for Social and Criminological Research (NCSCR), Giza 11561, Egypt
| | - Walaa H Mahmoud
- Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt
| | - Ahmed M El Kerdawy
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, Cairo, P.O. Box 11562, Egypt; Molecular Modeling Unit, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, Cairo, P.O. Box 11562, Egypt; Department of Pharmaceutical Chemistry, Faculty of Pharmacy, New Giza University, Newgiza, km 22 Cairo-Alexandria Desert Road, Cairo, Egypt
| | - Abanoub Mosaad Abdallah
- Narcotic Research Department, National Center for Social and Criminological Research (NCSCR), Giza 11561, Egypt.
| | - Gehad G Mohamed
- Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt; Egypt Nanotechnology Center, Cairo University, El-Sheikh Zayed, 6(th) October City, Giza 12588, Egypt
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Shurygin AV, Vovna VI, Korochentsev VV, Mirochnik AG, Sergienko VI. Electronic Structure of Eu(III) Adducts with OP(C6H5)3 and OP[NMe2]3. J STRUCT CHEM+ 2020. [DOI: 10.1134/s0022476619120084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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7
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Edelmann FT, Farnaby JH, Jaroschik F, Wilson B. Lanthanides and actinides: Annual survey of their organometallic chemistry covering the year 2018. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2019.07.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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8
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Zhai DD, Du HZ, Zhang XY, Liu YF, Guan BT. Potassium Yttrium Ate Complexes: Synergistic Effect Enabled Reversible H2 Activation and Catalytic Hydrogenation. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02899] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Dan-Dan Zhai
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Hui-Zhen Du
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Xiang-Yu Zhang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Yu-Feng Liu
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Bing-Tao Guan
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
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Evans KJ, Mansell SM. Synergic Deprotonation Generates Alkali-Metal Salts of Tethered Fluorenide-NHC Ligands Co-Complexed to Alkali-Metal Amides. Chemistry 2019; 25:3766-3769. [PMID: 30667554 PMCID: PMC6492165 DOI: 10.1002/chem.201806278] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Indexed: 11/23/2022]
Abstract
Synergic combinations of alkali‐metal hydrocarbyl/amide reagents were used to synthesise saturated N‐heterocyclic carbene (NHC) ligands tethered to a fluorenide anion through deprotonation of a spirocyclic precursor, whereas conventional bases were not successful. The Li2 derivatives displayed a bridging amide between two Li atoms within the fluorenide‐NHC pocket, whereas the Na2 and K2 analogues displayed extended solid‐state structures with the fluorenide‐NHC ligand chelating one alkali metal centre.
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Affiliation(s)
- Kieren J Evans
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - Stephen M Mansell
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
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Haddow MF, Newland RJ, Tegner BE, Mansell SM. Reversible temperature-induced polymorphic phase transitions of [Y(OAr) 3] and [Ce(OAr) 3] (Ar = 2,6- tBu 2-4-MeC 6H 2): interconversions between pyramidal and planar geometries. CrystEngComm 2019. [DOI: 10.1039/c9ce00184k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Exploring the balance of energetics between planar and pyramidal forms of [Y(O-2,6-tBu2-4-MePh)3] and related complexes.
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Affiliation(s)
- Mairi F. Haddow
- Institute of Chemical Sciences
- Heriot-Watt University
- Edinburgh
- UK
| | | | - Bengt E. Tegner
- Institute of Chemical Sciences
- Heriot-Watt University
- Edinburgh
- UK
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