1
|
Gentner T, Ballmann GM, Banerjee S, Kennedy AR, Robertson SD, Mulvey RE. Application of Bis(amido)alkyl Magnesiates toward the Synthesis of Molecular Rubidium and Cesium Hydrido-magnesiates. Organometallics 2024; 43:1393-1401. [PMID: 38938897 PMCID: PMC11200325 DOI: 10.1021/acs.organomet.4c00190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/03/2024] [Accepted: 06/05/2024] [Indexed: 06/29/2024]
Abstract
Rubidium and cesium are the least studied naturally occurring s-block metals in organometallic chemistry but are in plentiful supply from a sustainability viewpoint as highlighted in the periodic table of natural elements published by the European Chemical Society. This underdevelopment reflects the phenomenal success of organometallic compounds of lithium, sodium, and potassium, but interest in heavier congeners has started to grow. Here, the synthesis and structures of rubidium and cesium bis(amido)alkyl magnesiates [(AM)MgN'2alkyl]∞, where N' is the simple heteroamide -N(SiMe3)(Dipp), and alkyl is nBu or CH2SiMe3, are reported. More stable than their nBu analogues, the reactivities of the CH2SiMe3 magnesiates toward 1,4-cyclohexadiene are revealed. Though both reactions produce target hydrido-magnesiates [(AM)MgN'2H]2 in crystalline form amenable to X-ray diffraction study, the cesium compound could only be formed in a trace quantity. These studies showed that the bulk of the -N(SiMe3)(Dipp) ligand was sufficient to restrict both compounds to dimeric structures. Bearing some resemblance to inverse crown complexes, each structure has [(AM)(N)(Mg)(N)]2 ring cores but differ in having no AM-N bonds, instead Rb and Cs complete the rings by engaging in multihapto interactions with Dipp π-clouds. Moreover, their hydride ions occupy μ3-(AM)2Mg environments, compared to μ2-Mg2 environments in inverse crowns.
Collapse
Affiliation(s)
- Thomas
X. Gentner
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Gerd M. Ballmann
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Sumanta Banerjee
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Alan R. Kennedy
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Stuart D. Robertson
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Robert E. Mulvey
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
| |
Collapse
|
2
|
Golwankar RR, Curry TD, Paranjothi CJ, Blakemore JD. Molecular Influences on the Quantification of Lewis Acidity with Phosphine Oxide Probes. Inorg Chem 2023. [PMID: 36943934 DOI: 10.1021/acs.inorgchem.3c00084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Gutmann-Beckett-type measurements with phosphine oxide probes can be used to estimate effective Lewis acidity with 31P nuclear magnetic resonance spectroscopy, but the influence of the molecular structure of a given probe on the quantification of Lewis acidity remains poorly documented in experimental work. Here, a quantitative comparison of triethyl (E), trioctyl (O), and triphenyl (P) phosphine oxides as molecular probes of Lewis acidity has been carried out via titration studies in MeCN with a test set of six mono- and divalent metal triflate salts. In comparison to E, the bulkier O displays a similar range of chemical shift values and binding affinities for the various test metal ions. Spectral linewidths and speciation properties vary for individual cation-to-probe ratios, however, confirming probe-specific properties that can impact the data quality. Importantly, P displays a consistently narrower dynamic range than both E and O, illustrating how electronic changes at phosphorus can influence the NMR response. Comparative parametrizations of the effective Lewis acidities of a broader range of metal ions, including the trivalent rare earth ions Y3+, Lu3+, and Sc3+ as well as the uranyl ion (UO22+), can be understood in light of these results, providing insight into the fundamental chemical processes underlying the useful approach of single-point measurements for quantification of effective Lewis acidity. Together with a study of counteranion effects reported here, these data clarify the diverse ensemble of factors that can influence the measurement of Lewis acid/base interactions.
Collapse
Affiliation(s)
- Riddhi R Golwankar
- Department of Chemistry, University of Kansas, 1845 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - T Davis Curry
- Department of Chemistry, University of Kansas, 1845 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Cecilia J Paranjothi
- Department of Chemistry, University of Kansas, 1845 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - James D Blakemore
- Department of Chemistry, University of Kansas, 1845 Irving Hill Road, Lawrence, Kansas 66045, United States
| |
Collapse
|
3
|
Ballmann GM, Gentner TX, Kennedy AR, Hevia E, Mulvey RE. Heavy Alkali Metal Manganate Complexes: Synthesis, Structures and Solvent-Induced Dissociation Effects. Chemistry 2022; 28:e202201716. [PMID: 35775467 PMCID: PMC9804227 DOI: 10.1002/chem.202201716] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Indexed: 01/05/2023]
Abstract
Rare examples of heavier alkali metal manganates [{(AM)Mn(CH2 SiMe3 )(N'Ar )2 }∞ ] (AM=K, Rb, or Cs) [N'Ar =N(SiMe3 )(Dipp), where Dipp=2,6-iPr2 -C6 H3 ] have been synthesised with the Rb and Cs examples crystallographically characterised. These heaviest manganates crystallise as polymeric zig-zag chains propagated by AM⋅⋅⋅π-arene interactions. Key to their preparation is to avoid Lewis base donor solvents. In contrast, using multidentate nitrogen donors encourages ligand scrambling leading to redistribution of these bimetallic manganate compounds into their corresponding homometallic species as witnessed for the complete Li - Cs series. Adding to the few known crystallographically characterised unsolvated and solvated rubidium and caesium s-block metal amides, six new derivatives ([{AM(N'Ar )}∞ ], [{AM(N'Ar )⋅TMEDA}∞ ], and [{AM(N'Ar )⋅PMDETA}∞ ] where AM=Rb or Cs) have been structurally authenticated. Utilising monodentate diethyl ether as a donor, it was also possible to isolate and crystallographically characterise sodium manganate [(Et2 O)2 Na(n Bu)Mn[(N'Ar )2 ], a monomeric, dinuclear structure prevented from aggregating by two blocking ether ligands bound to sodium.
Collapse
Affiliation(s)
- Gerd M. Ballmann
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Thomas X. Gentner
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Alan R. Kennedy
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| | - Eva Hevia
- Department für Chemie und BiochemieUniversität BernFreiestrasse 33012BernSwitzerland
| | - Robert E. Mulvey
- WestCHEMDepartment of Pure and Applied ChemistryUniversity of StrathclydeGlasgowG1 1XLUK
| |
Collapse
|
4
|
Widemann M, Aicher FSW, Bonath M, Eichele K, Maichle‐Mössmer C, Schubert H, Sirsch P, Anwander R, Wesemann L. Molecular Ln(III)−H−E(II) Linkages (Ln=Y, Lu; E=Ge, Sn, Pb). Chemistry 2022; 28:e202201032. [PMID: 35620817 PMCID: PMC9541956 DOI: 10.1002/chem.202201032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Indexed: 11/09/2022]
Affiliation(s)
- Max Widemann
- Institut für Anorganische Chemie Eberhard Karls Universität Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Frederik S. W. Aicher
- Institut für Anorganische Chemie Eberhard Karls Universität Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Martin Bonath
- Institut für Anorganische Chemie Eberhard Karls Universität Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Klaus Eichele
- Institut für Anorganische Chemie Eberhard Karls Universität Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Cäcilia Maichle‐Mössmer
- Institut für Anorganische Chemie Eberhard Karls Universität Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Hartmut Schubert
- Institut für Anorganische Chemie Eberhard Karls Universität Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Peter Sirsch
- Institut für Anorganische Chemie Eberhard Karls Universität Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Reiner Anwander
- Institut für Anorganische Chemie Eberhard Karls Universität Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Lars Wesemann
- Institut für Anorganische Chemie Eberhard Karls Universität Tübingen Auf der Morgenstelle 18 72076 Tübingen Germany
| |
Collapse
|
5
|
Xin T, Wang X, Yang K, Liang J, Huang W. Rare Earth Metal Complexes Supported by a Tripodal Tris(amido) Ligand System Featuring an Arene Anchor. Inorg Chem 2021; 60:15321-15329. [PMID: 34569797 DOI: 10.1021/acs.inorgchem.1c01922] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new tripodal tris(amido) ligand system featuring an arene anchor was developed and applied to the coordination chemistry of rare earth metals. Two tris(amido) ligands with a 1,3,5-triphenylbenzene backbone were prepared in two steps from commercially available reagents on a gram scale. Salt metathesis and alkane elimination reactions were exploited to prepare mononuclear rare earth metal complexes in moderate to good yields. For salt metathesis reactions, while metal tribromides yielded neutral metal tris(amido) complexes, metal trichlorides led to the formation of ate complexes with an additional chloride bound to the metal center. The new compounds were characterized by X-ray crystallography, elemental analysis, and 1H and 13C nuclear magnetic resonance spectroscopy. The rare earth metal complexes exhibit a trigonal planar coordination geometry for the [MN3] fragment in the solid state rather than a trigonal pyramidal geometry, commonly observed for rare earth metal tris(amido) complexes such as M[N(SiMe3)2]3. Moreover, the arene anchor of the tripodal ligands is engaged in a nonnegligible interaction with the rare earth metal ions. Density functional theory calculations were performed to gain insight into the bonding interactions between the tripodal ligands and the rare earth metal ions. While LUMOs of these rare earth metal complexes are mainly π* orbitals of the arene with a minor component of metal-based orbitals, HOMO-15 and HOMO-16 of a lanthanum complex show that the arene anchor serves as a π donor to the trivalent lanthanum ion.
Collapse
Affiliation(s)
- Tiansi Xin
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Material Chemistry and Application, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Xinrui Wang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Material Chemistry and Application, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Kexin Yang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Material Chemistry and Application, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Jiefeng Liang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Material Chemistry and Application, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Wenliang Huang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Material Chemistry and Application, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| |
Collapse
|
6
|
Boteju KC, Venkatesh A, Chu YY, Wan S, Ellern A, Rossini AJ, Sadow AD. Ancillary Steric Effects on the Activation of SiH Bonds in Arylsilazido Rare-Earth Compounds. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kasuni C. Boteju
- US Department of Energy Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Amrit Venkatesh
- US Department of Energy Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Yang-Yun Chu
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Suchen Wan
- US Department of Energy Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States
| | - Arkady Ellern
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Aaron J. Rossini
- US Department of Energy Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Aaron D. Sadow
- US Department of Energy Ames Laboratory, Iowa State University, Ames, Iowa 50011, United States
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| |
Collapse
|
7
|
Moehring SA, Ziller JW, Evans WJ. Rare-earth complexes of the asymmetric amide ligands, N(SiMe3)Ph and N(SiMe3)Cy. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.04.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
8
|
Bienfait AM, Wolf BM, Törnroos KW, Anwander R. Trivalent Rare-Earth-Metal Bis(trimethylsilyl)amide Halide Complexes by Targeted Oxidations. Inorg Chem 2018; 57:5204-5212. [DOI: 10.1021/acs.inorgchem.8b00240] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- André M. Bienfait
- Department of Chemistry, University of Bergen, Allégaten 41, N-5007 Bergen, Norway
| | - Benjamin M. Wolf
- Institut für Anorganische Chemie, Universität Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
| | - Karl W. Törnroos
- Department of Chemistry, University of Bergen, Allégaten 41, N-5007 Bergen, Norway
| | - Reiner Anwander
- Institut für Anorganische Chemie, Universität Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
| |
Collapse
|
9
|
Lyubov DM, Cherkasov AV, Fukin GK, Lyssenko KA, Rychagova EA, Ketkov SY, Trifonov AA. Rare-earth metal-mediated PhCN insertion into N,N-bis(trimethylsilyl)naphthalene-1,8-diamido dianion – a synthetic approach to complexes coordinated by ansa-bridged amido-amidinato ligand. Dalton Trans 2018; 47:438-451. [DOI: 10.1039/c7dt03809g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the first example of rare earth metal-mediated insertion of PhCN into Si–N bonds with the formation of an amidinato moiety.
Collapse
Affiliation(s)
- Dmitry M. Lyubov
- Institute of Organometallic Chemistry of Russian Academy of Sciences
- Nizhny Novgorod
- Russia
| | - Anton V. Cherkasov
- Institute of Organometallic Chemistry of Russian Academy of Sciences
- Nizhny Novgorod
- Russia
| | - Georgy K. Fukin
- Institute of Organometallic Chemistry of Russian Academy of Sciences
- Nizhny Novgorod
- Russia
| | | | - Elena A. Rychagova
- Institute of Organometallic Chemistry of Russian Academy of Sciences
- Nizhny Novgorod
- Russia
| | - Sergey Yu. Ketkov
- Institute of Organometallic Chemistry of Russian Academy of Sciences
- Nizhny Novgorod
- Russia
| | - Alexander A. Trifonov
- Institute of Organometallic Chemistry of Russian Academy of Sciences
- Nizhny Novgorod
- Russia
- Institute of Organoelement compounds of Russian Academy of Sciences
- Moscow
| |
Collapse
|
10
|
Goodwin CAP, Chilton NF, Natrajan LS, Boulon ME, Ziller JW, Evans WJ, Mills DP. Investigation into the Effects of a Trigonal-Planar Ligand Field on the Electronic Properties of Lanthanide(II) Tris(silylamide) Complexes (Ln = Sm, Eu, Tm, Yb). Inorg Chem 2017; 56:5959-5970. [DOI: 10.1021/acs.inorgchem.7b00664] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Conrad A. P. Goodwin
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Nicholas F. Chilton
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Louise S. Natrajan
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | | | - Joseph W. Ziller
- Department
of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - William J. Evans
- Department
of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - David P. Mills
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| |
Collapse
|
11
|
Fuentes MÁ, Zabala A, Kennedy AR, Mulvey RE. Structural Diversity in Alkali Metal and Alkali Metal Magnesiate Chemistry of the Bulky 2,6-Diisopropyl-N-(trimethylsilyl)anilino Ligand. Chemistry 2016; 22:14968-14978. [PMID: 27573676 PMCID: PMC5096043 DOI: 10.1002/chem.201602683] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Indexed: 11/07/2022]
Abstract
Bulky amido ligands are precious in s-block chemistry, since they can implant complementary strong basic and weak nucleophilic properties within compounds. Recent work has shown the pivotal importance of the base structure with enhancement of basicity and extraordinary regioselectivities possible for cyclic alkali metal magnesiates containing mixed n-butyl/amido ligand sets. This work advances alkali metal and alkali metal magnesiate chemistry of the bulky arylsilyl amido ligand [N(SiMe3 )(Dipp)]- (Dipp=2,6-iPr2 -C6 H3 ). Infinite chain structures of the parent sodium and potassium amides are disclosed, adding to the few known crystallographically characterised unsolvated s-block metal amides. Solvation by N,N,N',N'',N''-pentamethyldiethylenetriamine (PMDETA) or N,N,N',N'-tetramethylethylenediamine (TMEDA) gives molecular variants of the lithium and sodium amides; whereas for potassium, PMDETA gives a molecular structure, TMEDA affords a novel, hemi-solvated infinite chain. Crystal structures of the first magnesiate examples of this amide in [MMg{N(SiMe3 )(Dipp)}2 (μ-nBu)]∞ (M=Na or K) are also revealed, though these breakdown to their homometallic components in donor solvents as revealed through NMR and DOSY studies.
Collapse
Affiliation(s)
- M Ángeles Fuentes
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
| | - Andoni Zabala
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
| | - Alan R Kennedy
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK
| | - Robert E Mulvey
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, G1 1XL, UK.
| |
Collapse
|
12
|
Spallek T, Heß O, Meermann-Zimmermann M, Meermann C, Klimpel MG, Estler F, Schneider D, Scherer W, Tafipolsky M, Törnroos KW, Maichle-Mössmer C, Sirsch P, Anwander R. Synthesis and structural diversity of trivalent rare-earth metal diisopropylamide complexes. Dalton Trans 2016; 45:13750-65. [PMID: 27471799 DOI: 10.1039/c6dt01568a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of rare-earth metal diisopropylamide complexes has been obtained via salt metathesis employing LnCl3(THF)x and lithium (LDA) or sodium diisopropylamide (NDA) in n-hexane. Reactions with AM : Ln ratios ≥3 gave ate complexes (AM)Ln(NiPr2)4(THF)n (n = 1, 2; Ln = Sc, Y, La, Lu; AM = Li, Na) in good yields. For smaller rare-earth metal centres such as scandium and lutetium, a Li : Ln ratio = 2.5 accomplished ate-free tris(amido) complexes Ln(NiPr2)3(THF). The chloro-bridged dimeric derivatives [Ln(NiPr2)2(μ-Cl)(THF)]2 (Ln = Sc, Y, La, Lu) could be obtained in high yields for Li : Ln = 1.6-2. The product resulting from the Li : La = 1 : 1.6 reaction revealed a crystal structure containing two different molecules in the crystal lattice, [La(NiPr2)2(THF)(μ-Cl)]2·La(NiPr2)3(THF)2. Recrystallization of the chloro-bridged dimers led to the formation of the monomeric species Ln(NiPr2)2Cl(THF)2 (Ln = Sc, Lu) and La(NiPr2)3(THF)2. The reaction of YCl3 and LDA with Li : Y = 2 in the absence of THF gave a bimetallic ate complex LiY(NiPr2)4 with a chain-like structure. For scandium, the equimolar reactions with LDA or NDA yielded crystals of tetrametallic mono(amido) species, {[Sc(NiPr2)Cl2(THF)]2(LiCl)}2 and [Sc(NiPr2)Cl2(THF)]4, respectively. Depending on the Ln(iii) size, AM, and presence of a donor solvent, ate complexes (AM)Ln(NiPr2)4(THF)n show distinct dynamic behaviour as revealed by variable temperature NMR spectroscopy. The presence of weak LnCH(iPr) β-agostic interactions, as indicated by Ln-N-C angles <105°, is corroborated by DFT calculations and NBO analysis.
Collapse
Affiliation(s)
- Tatiana Spallek
- Institut für Anorganische Chemie, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Goodwin CAP, Joslin KC, Lockyer SJ, Formanuik A, Morris GA, Ortu F, Vitorica-Yrezabal IJ, Mills DP. Homoleptic Trigonal Planar Lanthanide Complexes Stabilized by Superbulky Silylamide Ligands. Organometallics 2015. [DOI: 10.1021/om501123e] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Conrad A. P. Goodwin
- School
of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | - Kristian C. Joslin
- School
of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | - Selena J. Lockyer
- School
of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | - Alasdair Formanuik
- School
of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | - Gareth A. Morris
- School
of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | - Fabrizio Ortu
- School
of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | | | - David P. Mills
- School
of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| |
Collapse
|
14
|
Spinney HA, Clough CR, Cummins CC. The titanium tris-anilide cation [Ti(N[tBu]Ar)3]+ stabilized as its perfluoro-tetra-phenylborate salt: structural characterization and synthesis in connection with redox activity of 4,4′-bipyridine dititanium complexes. Dalton Trans 2015; 44:6784-96. [DOI: 10.1039/c5dt00105f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A rare cationic d0 metal tris-amide complex, containing an intriguing pyramidal TiN3 core geometry, namely {Ti(N[tBu]Ar)3}+, is isolated as its [B(C6F5)4]− salt.
Collapse
Affiliation(s)
- Heather A. Spinney
- 6-435 Department of Chemistry
- Massachusetts Institute of Technology
- Cambridge
- USA
| | | | | |
Collapse
|
15
|
Schädle D, Meermann-Zimmermann M, Maichle-Mössmer C, Schädle C, Törnroos KW, Anwander R. Rare-earth metal methylidene complexes with Ln3(μ3-CH2)(μ3-Me)(μ2-Me)3 core structure. Dalton Trans 2015; 44:18101-10. [DOI: 10.1039/c5dt02936h] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Although protected from intermolecular deactivation by a picket-fence-type arrangement of bulky amido ligands the CH22− moiety is readily converted into oxo species.
Collapse
Affiliation(s)
- Dorothea Schädle
- Institut für Anorganische Chemie
- Universität Tübingen
- D-72076 Tübingen
- Germany
| | | | | | - Christoph Schädle
- Institut für Anorganische Chemie
- Universität Tübingen
- D-72076 Tübingen
- Germany
| | | | - Reiner Anwander
- Institut für Anorganische Chemie
- Universität Tübingen
- D-72076 Tübingen
- Germany
| |
Collapse
|
16
|
Atom-efficient regioselective 1,2-dearomatization of functionalized pyridines by an earth-abundant organolanthanide catalyst. Nat Chem 2014; 6:1100-7. [PMID: 25411889 DOI: 10.1038/nchem.2087] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 09/12/2014] [Indexed: 12/22/2022]
Abstract
Developing earth-abundant, non-platinum metal catalysts for high-value chemical transformations is a critical challenge to contemporary chemical synthesis. Dearomatization of pyridine derivatives is an important transformation to access a wide range of valuable nitrogenous natural products, pharmaceuticals and materials. Here, we report an efficient 1,2-regioselective organolanthanide-catalysed pyridine dearomatization process using pinacolborane, which is compatible with a broad range of pyridines and functional groups and employs equimolar reagent stoichiometry. Regarding the mechanism, derivation of the rate law from NMR spectroscopic and kinetic measurements suggests first order in catalyst concentration, fractional order in pyridine concentration and inverse first order in pinacolborane concentration, with C=N insertion into the La-H bond as turnover-determining. An energetic span analysis affords a more detailed understanding of experimental activity trends and the unusual kinetic behaviour, and proposes the catalyst 'resting' state and potential deactivation pathways.
Collapse
|
17
|
Zhang X, Wang C, Xue M, Zhang Y, Yao Y, Shen Q. Syntheses of lanthanide monochloride and monoborohydride complexes supported by bridged bis(guanidinate) ligand and the use of borohydride complexes in polymerization of cyclic esters. J Organomet Chem 2012. [DOI: 10.1016/j.jorganchem.2012.05.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
18
|
Beck JF, Schmidt JAR. Isolation and characterization of main group and late transition metal complexes using orthometallated imine ligands. Dalton Trans 2012; 41:860-70. [DOI: 10.1039/c1dt11629k] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|