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Lee VY, Gapurenko OA. Pyramidanes: newcomers to the anti-van't Hoff-Le Bel family. Chem Commun (Camb) 2023; 59:10067-10086. [PMID: 37551825 DOI: 10.1039/d3cc02757k] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
In this feature article, an overview of the chemistry of pyramidanes, as a novel class of main group element clusters, is given. A general introduction sets the scene, briefly presenting the non-classical pyramidal geometry of tetracoordinate carbon, as opposed to the classical tetrahedral configuration. Pyramidanes, as the simplest organic compounds possessing a pyramidal carbon atom, are then discussed from both computational and experimental viewpoints, to show the theoretical predictions on the stability and thus the feasibility of pyramidanes has finally culminated in the isolation of the first stable representatives of the pyramidane family featuring heavy main group elements at the apex of the square pyramid. Synthetic strategies towards pyramidanes, as well as their peculiar structural features, non-classical bonding situations, and specific reactivity, are presented and discussed in this review.
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Affiliation(s)
- Vladimir Ya Lee
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Ibaraki, Japan.
| | - Olga A Gapurenko
- Institute of Physical and Organic Chemistry, Southern Federal University, Rostov on Don 344090, Russian Federation.
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2
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Tsoureas N, Rajeshkumar T, Townrow OPE, Maron L, Layfield RA. Thorium- and Uranium-Mediated C-H Activation of a Silyl-Substituted Cyclobutadienyl Ligand. Inorg Chem 2022; 61:20629-20635. [PMID: 36484644 PMCID: PMC9768750 DOI: 10.1021/acs.inorgchem.2c03534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cyclobutadienyl complexes of the f-elements are a relatively new yet poorly understood class of sandwich and half-sandwich organometallic compounds. We now describe cyclobutadienyl transfer reactions of the magnesium reagent [(η4-Cb'''')Mg(THF)3] (1), where Cb'''' is tetrakis(trimethylsilyl)cyclobutadienyl, toward thorium(IV) and uranium(IV) tetrachlorides. The 1:1 stoichiometric reactions between 1 and AnCl4 proceed with intact transfer of Cb'''' to give the half-sandwich complexes [(η4-Cb'''')AnCl(μ-Cl)3Mg(THF)3] (An = Th, 2; An = U, 3). Using a 2:1 reaction stoichiometry produces [Mg2Cl3(THF)6][(η4-Cb'''')An(η3-C4H(SiMe3)3-κ-(CH2SiMe2)(Cl)] (An = Th, [Mg2Cl3(THF)6][4]; An = U [Mg2Cl3(THF)6][5]), in which one Cb'''' ligand has undergone cyclometalation of a trimethylsilyl group, resulting in the formation of an An-C σ-bond, protonation of the four-membered ring, and an η3-allylic interaction with the actinide. Complex solution-phase dynamics are observed with multinuclear nuclear magnetic resonance spectroscopy for both sandwich complexes. A computational analysis of the reaction mechanism leading to the formation of 4 and 5 indicates that the cyclobutadienyl ligands undergo C-H activation across the actinide center.
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Affiliation(s)
- Nikolaos Tsoureas
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.
| | - Thayalan Rajeshkumar
- Laboratoire
de Physique et Chimie des Nano-Objets, Institut
National des Sciences Appliquées, Toulouse Cedex 4 31077, France
| | - Oliver P. E. Townrow
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
| | - Laurent Maron
- Laboratoire
de Physique et Chimie des Nano-Objets, Institut
National des Sciences Appliquées, Toulouse Cedex 4 31077, France,
| | - Richard A. Layfield
- Department
of Chemistry, School of Life Sciences, University
of Sussex, Brighton BN1 9QJ, U.K.,
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3
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Popov IA, Billow BS, Carpenter SH, Batista ER, Boncella JM, Tondreau AM, Yang P. An Allyl Uranium(IV) Sandwich Complex: Are ϕ Bonding Interactions Possible? Chemistry 2022; 28:e202200114. [PMID: 35286723 PMCID: PMC9322041 DOI: 10.1002/chem.202200114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Indexed: 01/08/2023]
Abstract
A method to explore head‐to‐head ϕ back‐bonding from uranium f‐orbitals into allyl π* orbitals has been pursued. Anionic allyl groups were coordinated to uranium with tethered anilide ligands, then the products were investigated by using NMR spectroscopy, single‐crystal XRD, and theoretical methods. The (allyl)silylanilide ligand, N‐((dimethyl)prop‐2‐enylsilyl)‐2,6‐diisopropylaniline (LH), was used as either the fully protonated, singly deprotonated, or doubly deprotonated form, thereby highlighting the stability and versatility of the silylanilide motif. A free, neutral allyl group was observed in UI2(L1)2 (1), which was synthesized by using the mono‐deprotonated ligand [K][N‐((dimethyl)prop‐2‐enyl)silyl)‐2,6‐diisopropylanilide] (L1). The desired homoleptic sandwich complex U[L2]2 (2) was prepared from all three ligand precursors, but the most consistent results came from using the dipotassium salt of the doubly deprotonated ligand [K]2[N‐((dimethyl)propenidesilyl)‐2,6‐diisopropylanilide] (L2). This allyl‐based sandwich complex was studied by using theoretical techniques with supporting experimental spectroscopy to investigate the potential for phi (ϕ) back‐bonding. The bonding between UIV and the allyl fragments is best described as ligand‐to‐metal electron donation from a two carbon fragment‐localized electron density into empty f‐orbitals.
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Affiliation(s)
- Ivan A. Popov
- Theoretical Division Los Alamos National Laboratory Los Alamos New Mexico 87545 USA
- Current address: Department of Chemistry The University of Akron Akron Ohio 44325-3601 USA
| | - Brennan S. Billow
- Chemistry Division Los Alamos National Laboratory MS J514 Los Alamos New Mexico 87545 USA
| | - Stephanie H. Carpenter
- Chemistry Division Los Alamos National Laboratory MS J514 Los Alamos New Mexico 87545 USA
| | - Enrique R. Batista
- Theoretical Division Los Alamos National Laboratory Los Alamos New Mexico 87545 USA
| | - James M. Boncella
- Department of Chemistry Washington State University and Pacific Northwest National Laboratory Pullman Washington 99164
- 902 Batelle Blvd Richland Washington 99352 USA
| | - Aaron M. Tondreau
- Chemistry Division Los Alamos National Laboratory MS J514 Los Alamos New Mexico 87545 USA
| | - Ping Yang
- Theoretical Division Los Alamos National Laboratory Los Alamos New Mexico 87545 USA
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4
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Durrant JP, Day BM, Tang J, Mansikkamäki A, Layfield RA. Dominance of Cyclobutadienyl Over Cyclopentadienyl in the Crystal Field Splitting in Dysprosium Single-Molecule Magnets. Angew Chem Int Ed Engl 2022; 61:e202200525. [PMID: 35108431 PMCID: PMC9302998 DOI: 10.1002/anie.202200525] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Indexed: 01/12/2023]
Abstract
Replacing a monoanionic cyclopentadienyl (Cp) ligand in dysprosium single‐molecule magnets (SMMs) with a dianionic cyclobutadienyl (Cb) ligand in the sandwich complexes [(η4‐Cb′′′′)Dy(η5‐C5Me4tBu)(BH4)]− (1), [(η4‐Cb′′′′)Dy(η8‐Pn†)K(THF)] (2) and [(η4‐Cb′′′′)Dy(η8‐Pn†)]− (3) leads to larger energy barriers to magnetization reversal (Cb′′′′=C4(SiMe3)4, Pn†=1,4‐di(tri‐isopropylsilyl)pentalenyl). Short distances to the Cb′′′′ ligands and longer distances to the Cp ligands in 1–3 are consistent with the crystal field splitting being dominated by the former. Theoretical analysis shows that the magnetic axes in the ground Kramers doublets of 1–3 are oriented towards the Cb′′′′ ligands. The theoretical axiality parameter and the relative axiality parameter Z and Zrel are introduced to facilitate comparisons of the SMM performance of 1–3 with a benchmark SMM. Increases in Z and Zrel when Cb′′′ replaces Cp signposts a route to SMMs with properties that could surpass leading systems.
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Affiliation(s)
- James P Durrant
- Department of Chemistry, University of Sussex Falmer, Brighton, BN1 9QR, UK
| | - Benjamin M Day
- Department of Chemistry, University of Sussex Falmer, Brighton, BN1 9QR, UK
| | - Jinkui Tang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun, Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P.R. China
| | | | - Richard A Layfield
- Department of Chemistry, University of Sussex Falmer, Brighton, BN1 9QR, UK
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5
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Durrant JP, Day BM, Tang J, Mansikkamäki A, Layfield RA. Dominance of Cyclobutadienyl Over Cyclopentadienyl in the Crystal Field Splitting in Dysprosium Single‐Molecule Magnets. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202200525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- James P. Durrant
- Department of Chemistry University of Sussex Falmer Brighton BN1 9QR UK
| | - Benjamin M. Day
- Department of Chemistry University of Sussex Falmer Brighton BN1 9QR UK
| | - Jinkui Tang
- State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 P.R. China
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6
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Thomas-Hargreaves LR, Giansiracusa MJ, Gregson M, Zanda E, O'Donnell F, Wooles AJ, Chilton NF, Liddle ST. Correlating axial and equatorial ligand field effects to the single-molecule magnet performances of a family of dysprosium bis-methanediide complexes. Chem Sci 2021; 12:3911-3920. [PMID: 34163660 PMCID: PMC8179472 DOI: 10.1039/d1sc00238d] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/01/2021] [Indexed: 11/21/2022] Open
Abstract
Treatment of the new methanediide-methanide complex [Dy(SCS)(SCSH)(THF)] (1Dy, SCS = {C(PPh2S)2}2-) with alkali metal alkyls and auxillary ethers produces the bis-methanediide complexes [Dy(SCS)2][Dy(SCS)2(K(DME)2)2] (2Dy), [Dy(SCS)2][Na(DME)3] (3Dy) and [Dy(SCS)2][K(2,2,2-cryptand)] (4Dy). For further comparisons, the bis-methanediide complex [Dy(NCN)2][K(DB18C6)(THF)(toluene)] (5Dy, NCN = {C(PPh2NSiMe3)2}2-, DB18C6 = dibenzo-18-crown-6 ether) was prepared. Magnetic susceptibility experiments reveal slow relaxation of the magnetisation for 2Dy-5Dy, with open magnetic hysteresis up to 14, 12, 15, and 12 K, respectively (∼14 Oe s-1). Fitting the alternating current magnetic susceptibility data for 2Dy-5Dy gives energy barriers to magnetic relaxation (U eff) of 1069(129)/1160(21), 1015(32), 1109(70), and 757(39) K, respectively, thus 2Dy-4Dy join a privileged group of SMMs with U eff values of ∼1000 K and greater with magnetic hysteresis at temperatures >10 K. These structurally similar Dy-components permit systematic correlation of the effects of axial and equatorial ligand fields on single-molecule magnet performance. For 2Dy-4Dy, the Dy-components can be grouped into 2Dy-cation/4Dy and 2Dy-anion/3Dy, where the former have almost linear C[double bond, length as m-dash]Dy[double bond, length as m-dash]C units with short average Dy[double bond, length as m-dash]C distances, and the latter have more bent C[double bond, length as m-dash]Dy[double bond, length as m-dash]C units with longer average Dy[double bond, length as m-dash]C bonds. Both U eff and hysteresis temperature are superior for the former pair compared to the latter pair as predicted, supporting the hypothesis that a more linear axial ligand field with shorter M-L distances produces enhanced SMM properties. Comparison with 5Dy demonstrates unusually clear-cut examples of: (i) weakening the equatorial ligand field results in enhancement of the SMM performance of a monometallic system; (ii) a positive correlation between U eff barrier and axial linearity in structurally comparable systems.
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Affiliation(s)
| | - Marcus J Giansiracusa
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Matthew Gregson
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Emanuele Zanda
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Felix O'Donnell
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Ashley J Wooles
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Nicholas F Chilton
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Stephen T Liddle
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
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7
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Tsoureas N, Mansikkamäki A, Layfield RA. Synthesis, bonding properties and ether activation reactivity of cyclobutadienyl-ligated hybrid uranocenes. Chem Sci 2021; 12:2948-2954. [PMID: 34164062 PMCID: PMC8179396 DOI: 10.1039/d0sc05199c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 01/07/2021] [Indexed: 11/21/2022] Open
Abstract
A series of hybrid uranocenes consisting of uranium(iv) sandwiched between cyclobutadienyl (Cb) and cyclo-octatetraenyl (COT) ligands has been synthesized, structurally characterized and studied computationally. The dimetallic species [(η4-Cb'''')(η8-COT)U(μ:η2:η8-COT)U(THF)(η4-Cb'''')] (1) forms concomitantly with, and can be separated from, monometallic [(η4-Cb'''')U(THF)(η8-COT)] (2) (Cb'''' = 1,2,3,4-tetrakis(trimethylsilyl)cyclobutadienyl, COT = cyclo-octatetraenyl). In toluene solution at room temperature, 1 dissociates into 2 and the unsolvated uranocene [(η4-Cb'''')U(η8-COT)] (3). By applying a high vacuum, both 1 and 2 can be converted directly into 3. Using bulky silyl substituents on the COT ligand allowed isolation of base-free [(η4-Cb'''')U{η8-1,4-(iPr3Si)2C8H6}] (4), with compounds 3 and 4 being new members of the bis(annulene) family of actinocenes and the first to contain a cyclobutadienyl ligand. Computational studies show that the bonding in the hybrid uranocenes 3 and 4 has non-negligible covalency. New insight into actinocene bonding is provided by the complementary interactions of the different ligands with uranium, whereby the 6d orbitals interact most strongly with the cyclobutadienyl ligand and the 5f orbitals do so with the COT ligands. The redox-neutral activation of diethyl ether by [(η4-Cb'''')U(η8-C8H8)] is also described and represents a uranium-cyclobutadienyl cooperative process, potentially forming the basis of further small-molecule activation chemistry.
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Affiliation(s)
- Nikolaos Tsoureas
- Department of Chemistry, School of Life Sciences, University of Sussex Brighton BN1 9QJ UK
| | | | - Richard A Layfield
- Department of Chemistry, School of Life Sciences, University of Sussex Brighton BN1 9QJ UK
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8
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Yu C, Wu B, Yang Z, Chen H, Zhang WX, Xi Z. Inverse-Sandwich Cyclobutadiene Dinickel Complexes: Synthesis and Structural Characterization. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2020. [DOI: 10.1246/bcsj.20200156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Chao Yu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, P. R. China
| | - Botao Wu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, P. R. China
| | - Zhenqiang Yang
- Henan Institute of Chemistry Co. Ltd., Henan Academy of Sciences, Zhengzhou 450002, P. R. China
| | - Hui Chen
- Henan Institute of Chemistry Co. Ltd., Henan Academy of Sciences, Zhengzhou 450002, P. R. China
| | - Wen-Xiong Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, P. R. China
| | - Zhenfeng Xi
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, P. R. China
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry (SIOC), Shanghai 200032, P. R. China
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Goodwin CAP. Blocking like it's hot: a synthetic chemists' path to high-temperature lanthanide single molecule magnets. Dalton Trans 2020; 49:14320-14337. [PMID: 33030172 DOI: 10.1039/d0dt01904f] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Progress in the synthesis, design, and characterisation of single-molecule magnets (SMMs) has expanded dramatically from curiosity driven beginnings to molecules that retain magnetization above the boiling point of liquid nitrogen. This is in no small part due to the increasingly collaborative nature of this research where synthetic targets are guided by theoretical design criteria. This article aims to summarize these efforts and progress from the perspective of a synthetic chemist with a focus on how chemistry can modulate physical properties. A simple overview is presented of lanthanide electronic structure in order to contextualize the synthetic advances that have led to drastic improvements in the performance of lanthanide-based SMMs from the early 2000s to the late 2010s.
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Affiliation(s)
- Josef T. Boronski
- Department of Chemistry; The University of Manchester; Oxford Road M13 9PL Manchester UK
| | - Stephen T. Liddle
- Department of Chemistry; The University of Manchester; Oxford Road M13 9PL Manchester UK
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11
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He M, Guo FS, Tang J, Mansikkamäki A, Layfield RA. Fulvalene as a platform for the synthesis of a dimetallic dysprosocenium single-molecule magnet. Chem Sci 2020; 11:5745-5752. [PMID: 32832050 PMCID: PMC7422961 DOI: 10.1039/d0sc02033h] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 05/15/2020] [Indexed: 12/20/2022] Open
Abstract
The dinucleating fulvalenyl ligand [1,1',3,3'-(C5 t Bu2H2)2]2- (Fvtttt) was used to synthesize the dimetallic dysprosocenium cation [{Dy(η5-Cp*)}2(μ-BH4)(η5:η5-Fvtttt)]+ (3) as the salt of [B(C6F5)4]- (Cp* = C5Me5). Compound [3][B(C6F5)4] was obtained using a method in which the double half-sandwich complex [{Dy(BH4)2(THF)}2(Fvtttt)] (1) was reacted with KCp* to give the double metallocene [{Dy(Cp*)(μ-BH4)}2(Fvtttt)] (2), followed by removal of a bridging borohydride ligand upon addition of [(Et3Si)2(μ-H)][B(C6F5)4]. The dimetallic fulvalenyl complexes 1-3 give rise to single-molecule magnet (SMM) behaviour in zero applied field, with the effective energy barriers of 154(15) cm-1, 252(4) cm-1 and 384(18) cm-1, respectively, revealing a significant improvement in performance across the series. The magnetic properties are interpreted with the aid of ab initio calculations, which show substantial increases in the axiality of the crystal field from 1 to 2 to 3 as a consequence of the increasingly dominant role of the Fvtttt and Cp* ligands, with the barrier height and hysteresis properties being attenuated by the equatorial borohydride ligands. The experimental and theoretical results described in this study furnish a blueprint for the design and synthesis of poly-cationic dysprosocenium SMMs with properties that may surpass those of benchmark systems.
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Affiliation(s)
- Mian He
- Department of Chemistry , School of Life Sciences , University of Sussex , Brighton , BN1 9QR , UK .
| | - Fu-Sheng Guo
- Department of Chemistry , School of Life Sciences , University of Sussex , Brighton , BN1 9QR , UK .
| | - Jinkui Tang
- Changchun Institute of Applied Chemistry , Chinese Academy of Sciences , Renmin Street 5626 , 130022 Changchun , China .
| | - Akseli Mansikkamäki
- NMR Research Unit , University of Oulu , P.O. Box 8000, FI-90014 , Finland .
| | - Richard A Layfield
- Department of Chemistry , School of Life Sciences , University of Sussex , Brighton , BN1 9QR , UK .
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12
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Boronski JT, Doyle LR, Wooles AJ, Seed JA, Liddle ST. Synthesis and Characterization of an Oxo-Centered Homotrimetallic Uranium(IV)–Cyclobutadienyl Dianion Complex. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00104] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Josef T. Boronski
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Laurence R. Doyle
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Ashley J. Wooles
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - John A. Seed
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Stephen T. Liddle
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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13
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Durrant JP, Tang J, Mansikkamäki A, Layfield RA. Enhanced single-molecule magnetism in dysprosium complexes of a pristine cyclobutadienyl ligand. Chem Commun (Camb) 2020; 56:4708-4711. [PMID: 32215423 DOI: 10.1039/d0cc01722a] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Intact transfer of the cyclobutadienyl ligand [C4(SiMe3)4]2- to yttrium and dysprosium (M) produces the half-sandwich complexes [M{η4-C4(SiMe3)4}(BH4)2(THF)]- as coordination polymers with bridging sodium or potassium ions. The dysprosium versions are single-molecule magnets (SMMs) with energy barriers of 371(7) and 357(4) cm-1, respectively. The pristine cyclobutadienyl ligands provide a strong axial crystal field that enhances the SMM properties relative to related cyclopentadienyl compounds.
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Affiliation(s)
- James P Durrant
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QR, UK. and School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Jinkui Tang
- Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5626, 130022 Changchun, China
| | | | - Richard A Layfield
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton, BN1 9QR, UK.
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