1
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Pearce KG, Neale SE, Mahon MF, McMullin CL, Hill MS. Alkali metal reduction of crown ether encapsulated alkali metal cations. Chem Commun (Camb) 2024; 60:8391-8394. [PMID: 39037395 DOI: 10.1039/d4cc02725f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2024]
Abstract
[{SiNDipp}BeClM]2 ({SiNDipp} = {CH2SiMe2N(Dipp)}2; M = Li, Na, K, Rb) are converted to ionic species by treatment with a crown ether. Whereas the lithium derivative reacts with Na or K to provide [{SiNDipp}BeCl]-[M(12-cr-4)2]+ (M = Na, K), the resultant sodium species is resistant to reduction by potassium. These observations are rationalised by a hybrid experimental/theoretical analysis.
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Affiliation(s)
- Kyle G Pearce
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Samuel E Neale
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Mary F Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Claire L McMullin
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Michael S Hill
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
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2
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Boronski JT, Crumpton AE, Roper AF, Aldridge S. A nucleophilic beryllyl complex via metathesis at [Be-Be] 2. Nat Chem 2024; 16:1295-1300. [PMID: 38760434 DOI: 10.1038/s41557-024-01534-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 04/10/2024] [Indexed: 05/19/2024]
Abstract
Owing to its high toxicity, the chemistry of element number four, beryllium, is poorly understood. However, as the lightest elements provide the basis for fundamental models of chemical bonding, there is a need for greater insight into the properties of beryllium. In this context, the chemistry of the homo-elemental Be-Be bond is of fundamental interest. Here the ligand metathesis chemistry of diberyllocene (1; CpBeBeCp)-a stable complex with a Be-Be bond-has been investigated. These studies yield two complexes with Be-Be bonds: Cp*BeBeCp (2) and [K{(HCDippN)2BO}2]BeBeCp (3; Dipp = 2,6-diisopropylphenyl). Quantum chemical calculations indicate that the Be-Be bond in 3 is polarized to such an extent that the complex could be formulated as a mixed-oxidation state Be0/BeII complex. Correspondingly, it is demonstrated that 3 can transfer the 'beryllyl' anion, [BeCp]-, to an organic substrate, by analogy with the reactivity of sp2-sp3 diboranes. Indeed, this work reveals striking similarities between the homo-elemental bonding linkages of beryllium and boron, despite the respective metallic and non-metallic natures of these elements.
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Affiliation(s)
- Josef T Boronski
- Chemistry Research Laboratory Department of Chemistry, University of Oxford, Oxford, UK.
| | - Agamemnon E Crumpton
- Chemistry Research Laboratory Department of Chemistry, University of Oxford, Oxford, UK
| | - Aisling F Roper
- Chemistry Research Laboratory Department of Chemistry, University of Oxford, Oxford, UK
| | - Simon Aldridge
- Chemistry Research Laboratory Department of Chemistry, University of Oxford, Oxford, UK.
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3
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Leach IF, Klein JEMN. Oxidation States: Intrinsically Ambiguous? ACS CENTRAL SCIENCE 2024; 10:1406-1414. [PMID: 39071055 PMCID: PMC11273457 DOI: 10.1021/acscentsci.4c00825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 06/10/2024] [Accepted: 06/10/2024] [Indexed: 07/30/2024]
Abstract
The oxidation state ( OS ) formalism is a much-appreciated good in chemistry, receiving wide application. However, like all formalisms, limitations are inescapable, some of which have been recently explored. Providing a broader context, we discuss the OS and its interpretation from a computational perspective for transition metal (TM) complexes. We define a broadly applicable and easy-to-use procedure to derive OS s based on quantum chemical calculations, via the use of localized orbitals, dubbed the Intrinsic OS . Applying this approach to a cobalt complex in five OS s, isolated by Hunter and co-workers (Inorg. Chem.2021, 60, 17445), we find that the calculated Intrinsic OS matches the formal OS , consistent with the experimental characterization. Through analysis of the delocalized orbitals, the ligand field of the Co(III) complex is found to be "inverted", despite every cobalt-ligand bond being classically dative from the localized perspective-a bonding scenario very similar to that of [Cu(CF3)4]-. This is not atypical but rather a natural consequence of these metals bonding in the high-valent region, and we propose a more restrictive definition of (locally) inverted bonding. Additionally, two bonding descriptors within the Intrinsic Bonding Orbital (IBO) framework (σ-gain and π-loss) are introduced, which enable facile quantification of electron-sharing covalency across a broad range of TM complexes.
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Affiliation(s)
- Isaac F. Leach
- Molecular
Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 3, 9747
AG Groningen, The
Netherlands
- Zernike
Institute for Advanced Materials, University
of Groningen, Nijenborgh
3, 9747 AG Groningen, The Netherlands
| | - Johannes E. M. N. Klein
- Molecular
Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 3, 9747
AG Groningen, The
Netherlands
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4
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Evans MJ, Jones C. Low oxidation state and hydrido group 2 complexes: synthesis and applications in the activation of gaseous substrates. Chem Soc Rev 2024; 53:5054-5082. [PMID: 38595211 DOI: 10.1039/d4cs00097h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Numerous industrial processes utilise gaseous chemical feedstocks to produce useful chemical products. Atmospheric and other small molecule gases, including anthropogenic waste products (e.g. carbon dioxide), can be viewed as sustainable building blocks to access value-added chemical commodities and materials. While transition metal complexes have been well documented in the reduction and transformation of these substrates, molecular complexes of the terrestrially abundant alkaline earth metals have also demonstrated promise with remarkable reactivity reported towards an array of industrially relevant gases over the past two decades. This review covers low oxidation state and hydrido group 2 complexes and their role in the reduction and transformation of a selection of important gaseous substrates towards value-added chemical products.
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Affiliation(s)
- Matthew J Evans
- School of Chemistry, Monash University, PO Box 23, Melbourne, Victoria, 3800, Australia.
| | - Cameron Jones
- School of Chemistry, Monash University, PO Box 23, Melbourne, Victoria, 3800, Australia.
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5
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Liu YQ, Kalita AJ, Zhang HY, Cui LJ, Yan B, Guha AK, Cui ZH, Pan S. BeM(CO)3- (M = Co, Rh, Ir) and BeM(CO)3 (M = Ni, Pd, Pt): Triply bonded terminal beryllium in zero oxidation state. J Chem Phys 2024; 160:184308. [PMID: 38738611 DOI: 10.1063/5.0181343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 04/25/2024] [Indexed: 05/14/2024] Open
Abstract
We perform detailed potential energy surface explorations of BeM(CO)3- (M = Co, Rh, Ir) and BeM(CO)3 (M = Ni, Pd, Pt) using both single-reference and multireference-based methods. The present results at the CASPT2(12,12)/def2-QZVPD//M06-D3/def2-TZVPPD level reveal that the global minimum of BeM(CO)3- (M = Co, Rh, Ir) and BePt(CO)3 is a C3v symmetric structure with an 1A1 electronic state, where Be is located in a terminal position bonded to M along the center axis. For other cases, the C3v symmetric structure is a low-lying local minimum. Although the present complexes are isoelectronic with the recently reported BFe(CO)3- complex having a B-Fe quadruple bond, radial orbital-energy slope (ROS) analysis reveals that the highest occupied molecular orbital (HOMO) in the title complexes is slightly antibonding in nature, which bars a quadruple bonding assignment. Similar weak antibonding nature of HOMO in the previously reported BeM(CO)4 (M = Ru, Os) complexes is also noted in ROS analysis. The bonding analysis through energy decomposition analysis in combination with the natural orbital for chemical valence shows that the bonding between Be and M(CO)3q (q = -1 for M = Co, Rh, Ir and q = 0 for M = Ni, Pd, Pt) can be best described as Be in the ground state (1S) interacting with M(CO)30/- via dative bonds. The Be(spσ) → M(CO)3q σ-donation and the complementary Be(spσ) ← M(CO)3q σ-back donation make the overall σ bond, which is accompanied by two weak Be(pπ) ← M(CO)3q π-bonds. These complexes represent triply bonded terminal beryllium in an unusual zero oxidation state.
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Affiliation(s)
- Yu-Qian Liu
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - Amlan J Kalita
- Department of Chemistry, University of Science & Technology, Meghalaya, Ri-Bhoi, Meghalaya 793101, India
| | - Hui-Yu Zhang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - Li-Juan Cui
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - Bing Yan
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - Ankur K Guha
- Advanced Computational Chemistry Centre, Department of Chemistry, Cotton University, Panbazar, Guwahati, Assam 781001, India
| | - Zhong-Hua Cui
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin University, Changchun 130023, China
| | - Sudip Pan
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
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6
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Parveen D, Yadav RK, Roy DK. Recent progress in beryllium organometallic chemistry. Chem Commun (Camb) 2024; 60:1663-1673. [PMID: 38260953 DOI: 10.1039/d3cc04844f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Beryllium possesses a unique amalgamation of characteristics, its electronegativity included, that not only make it a vital component in a wide range of technical sectors and consumer industries, but also make it an interesting candidate for forming covalently bonded compounds. However, the extremely toxic nature of beryllium, which can cause chronic beryllium disease, has limited the exploration of its chemistry, making beryllium one of the least studied (non-radioactive) elements. The development of selective chelating ligands, sterically encumbered substituents and, moreover, the boom of N-heterocyclic carbenes in organometallic chemistry and main group chemistry has revived the interest in beryllium chemistry. Therefore, some quite remarkable progress in the coordination and organometallic chemistry of beryllium has been made in the last two decades. For example, low oxidation state beryllium compounds, antiaromatic/aromatic beryllium compounds, where beryllium is involved in π-electron delocalization, and the isolation of beryllium-beryllium bonded species have all been achieved. This article provides an oversight over the recent developments in the organometallic chemistry of beryllium.
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Affiliation(s)
- Darakshan Parveen
- Department of Chemistry, Indian Institute of Technology Indore, Madhya Pradesh, 453552, India.
| | - Rahul Kumar Yadav
- Department of Chemistry, Indian Institute of Technology Indore, Madhya Pradesh, 453552, India.
| | - Dipak Kumar Roy
- Department of Chemistry, Indian Institute of Technology Indore, Madhya Pradesh, 453552, India.
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7
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Czernetzki C, Arrowsmith M, Endres L, Krummenacher I, Braunschweig H. Tricoordinate Beryllium Radicals and Their Reactivity. Inorg Chem 2024; 63:2670-2678. [PMID: 38259240 DOI: 10.1021/acs.inorgchem.3c04014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The one-electron reduction of [(CAAC)Be(Dur)Br] (CAAC = cyclic alkyl(amino)carbene, Dur = 2,3,5,6-tetramethylphenyl = duryl) with lithium sand in diethyl ether yields the first neutral, tricoordinate, and moderately stable beryllium radical, [(CAAC)(Et2O)BeDur]• (2-Et2O), which undergoes a facile second one-electron reduction concomitant with the insertion of the beryllium center into the endocyclic C-NCAAC bond and a cyclopropane-forming C-H bond activation of an adjacent methyl group. In situ generation of 2-Et2O and addition of PMe3 yield the stable analogue, [(CAAC)(Me3P)BeDur]• (2-PMe3), which serves as a platform for PMe3-ligand exchange with stronger donors, generating the radicals [(CAAC)LBeDur]• (2-L, L = isocyanides, pyridines, and N-heterocyclic carbenes). X-ray structural analyses show trigonal-planar beryllium centers and strong π backbonding from the metal to the CAAC ligand. The EPR signals of all six isolated [(CAAC)LBeDur]• radicals display significant, albeit small, hyperfine coupling to the 9Be nucleus. DFT calculations show that the spin density is mostly delocalized over the CAAC π framework and, where present, the isocyanide CN moiety, with only a small proportion (3-6%) on the beryllium center. 2-PMe3 proved thermally unstable at 80 °C, first undergoing radical hydrogen abstraction with the solvent, followed by insertion of beryllium into the endocyclic C-NCAAC bond and PMe3 transfer to the former carbene carbon atom. The reactions with diphenyl disulfide and phenyl azide occur at the beryllium center and yield the corresponding Be(II) phenyl sulfide and amino complexes, respectively, the latter concomitant with radical transfer and hydrogen abstraction by the beryllium-bound nitrogen center.
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Affiliation(s)
- Corinna Czernetzki
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Merle Arrowsmith
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Lukas Endres
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Ivo Krummenacher
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
| | - Holger Braunschweig
- Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
- Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg 97074, Germany
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8
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Townrow OPE, Färber C, Zenneck U, Harder S. Metal Vapour Synthesis of an Organometallic Barium(0) Synthon. Angew Chem Int Ed Engl 2023:e202318428. [PMID: 38078903 DOI: 10.1002/anie.202318428] [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: 12/01/2023] [Indexed: 12/23/2023]
Abstract
A hydrocarbon-soluble barium anthracene complex was prepared by means of metal vapour synthesis. Reaction of 9,10-bis(trimethylsilyl)anthracene (Anth'') with barium vapour gave deep purple Ba(Anth'') which after extraction with diethyl ether crystallised as the cyclic octamer [Ba(Anth'')⋅Et2 O]8 . Dissolution in benzene or toluene led to replacement of the Et2 O ligand with a softer arene ligand and isolation of Ba(Anth'')⋅arene. Diffusion ordered spectroscopy (DOSY NMR ) measurements in benzene-d6 indicate solution species with a molecular weight that equals a trimeric constitution. Natural population analysis (NPA) assigned charges of +1.70 and -1.70 to Ba and Anth'', respectively, relating to highly ionic Ba2+ /Anth''2- bonding. Preliminary reactivity studies with air, Ph2 C=NPh, or H2 show that the complex reacts as a Ba0 synthon by release of neutral Anth''. This soluble molecular Ba0 /BaII redox synthon provides new routes for the syntheses of barium complexes under mild conditions.
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Affiliation(s)
- Oliver P E Townrow
- Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Christian Färber
- Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Ulrich Zenneck
- Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry, Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058, Erlangen, Germany
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9
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Polaczek J, Kieca K, Oszajca M, Impert O, Katafias A, Chatterjee D, Ćoćić D, Puchta R, Stochel G, Hubbard CD, van Eldik R. A Personal Account on Inorganic Reaction Mechanisms. CHEM REC 2023:e202300278. [PMID: 37821418 DOI: 10.1002/tcr.202300278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/22/2023] [Indexed: 10/13/2023]
Abstract
The presented Review is focused on the latest research in the field of inorganic chemistry performed by the van Eldik group and his collaborators. The first part of the manuscript concentrates on the interaction of nitric oxide and its derivatives with biologically important compounds. We summarized mechanistic information on the interaction between model porphyrin systems (microperoxidase) and NO as well as the recent studies on the formation of nitrosylcobalamin (CblNO). The following sections cover the characterization of the Ru(II)/Ru(III) mixed-valence ion-pair complexes, including Ru(II)/Ru(III)(edta) complexes. The last part concerns the latest mechanistic information on the DFT techniques applications. Each section presents the most important results with the mechanistic interpretations.
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Affiliation(s)
- Justyna Polaczek
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland
| | - Konrad Kieca
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland
- Jagiellonian University, Doctoral School of Exact and Natural Sciences, Kraków, 30-348, Krakow, Poland
| | - Maria Oszajca
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland
| | - Olga Impert
- Faculty of Chemistry, Nicolaus Copernicus University in Torun, Gagarina 7, 87-100, Torun, Poland
| | - Anna Katafias
- Faculty of Chemistry, Nicolaus Copernicus University in Torun, Gagarina 7, 87-100, Torun, Poland
| | - Debabrata Chatterjee
- Faculty of Chemistry, Nicolaus Copernicus University in Torun, Gagarina 7, 87-100, Torun, Poland
- Vice-Chancellor's Research Group, Zoology Department, University of Burdwan, Burdwan, 713104, India
| | - Dušan Ćoćić
- University of Kragujevac, Faculty of Science, Department of Chemistry, Radoja Domanovića 12, P. O. Box 60, 34000, Kragujevac, Serbia
| | - Ralph Puchta
- Department of Chemistry and Pharmacy, University of Erlangen-Nuremberg, Egerlandstrasse 1, 91058, Erlangen, Germany
- Central Institute for Scientific Computing (CISC), University of Erlangen-Nuremberg, Martensstr. 5a, 91058, Erlangen, Germany
- Computer Chemistry Center, Department of Chemistry and Pharmacy, University of Erlangen-Nuremberg, Nägelsbachstr. 25, 91052, Erlangen, Germany
| | - Grażyna Stochel
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland
| | - Colin D Hubbard
- Department of Chemistry, University of New Hampshire, Durham, 03824, USA
| | - Rudi van Eldik
- Department of Chemistry and Pharmacy, University of Erlangen-Nuremberg, Egerlandstrasse 1, 91058, Erlangen, Germany
- Faculty of Chemistry, Nicolaus Copernicus University in Torun, Gagarina 7, 87-100, Torun, Poland
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10
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Wu CS, Su MD. Reactivity Analysis of the [2 + 2] Cycloaddition between Group-6 ≡ Group-14 Triple-Bonded Complexes and Acetylene: Insights from Theoretical Studies. Inorg Chem 2023; 62:16388-16400. [PMID: 37768726 DOI: 10.1021/acs.inorgchem.3c02020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
Theoretical examinations of reactivity for the formal [2 + 2] cycloaddition of Me-C≡C-Ph to Group-6(G6)≡Group-14(G14) triple-bonded organometallic complexes have been carried out using the M06-2X-D3/def2-TZVP level of theory. Our theoretical findings suggest that Me-C≡C-Ph can undergo adduct formation with all G6≡Si complexes, resulting in the generation of four-membered ring structures. However, among the W≡Group-14 complex reactants, only W≡Si-based, W≡Ge-based, and W≡Sn-based organometallic molecules are capable of undergoing a [2 + 2] cycloaddition reaction with Me-C≡C-Ph. Based on energy decomposition analysis, our theoretical investigations demonstrate that the bonding mechanism in such [2 + 2] cycloaddition reactions involves the creation of two dative bonds between singlet fragments (the donor-acceptor model), as opposed to two electron-sharing bonds between triplet fragments. In addition, the examinations based on the activation strain model indicate that the activation barrier of the [2 + 2] cycloaddition reaction is predominantly governed by the geometric deformation energy of the two reactants (G6≡G14-Rea and Me-C≡C-Ph). Our research using the M06-2X method shows that the barrier heights of [2 + 2] cycloaddition reactions between Me-C≡C-Ph and G6≡Si-Rea are dependent on the geometric changes occurring in both fragments during the transition states, consistent with Hammond's postulate.
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Affiliation(s)
- Chi-Shiun Wu
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan
| | - Ming-Der Su
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
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11
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Boronski JT, Crumpton AE, Wales LL, Aldridge S. Diberyllocene, a stable compound of Be(I) with a Be-Be bond. Science 2023; 380:1147-1149. [PMID: 37319227 DOI: 10.1126/science.adh4419] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 04/25/2023] [Indexed: 06/17/2023]
Abstract
The complex diberyllocene, CpBeBeCp (Cp, cyclopentadienyl anion), has been the subject of numerous chemical investigations over the past five decades yet has eluded experimental characterization. We report the preparation and isolation of the compound by the reduction of beryllocene (BeCp2) with a dimeric magnesium(I) complex and determination of its structure in the solid state by means of x-ray crystallography. Diberyllocene acts as a reductant in reactions that form beryllium-aluminum and beryllium-zinc bonds. Quantum chemical calculations indicate parallels between the electronic structure of diberyllocene and the simple homodiatomic species diberyllium (Be2).
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Affiliation(s)
- Josef T Boronski
- Chemistry Research Laboratory, Department of Chemistry, Oxford, OX1 3TA, UK
| | | | - Lewis L Wales
- Chemistry Research Laboratory, Department of Chemistry, Oxford, OX1 3TA, UK
| | - Simon Aldridge
- Chemistry Research Laboratory, Department of Chemistry, Oxford, OX1 3TA, UK
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12
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Mai J, Rösch B, Patel N, Langer J, Harder S. On the existence of low-valent magnesium-calcium complexes. Chem Sci 2023; 14:4724-4734. [PMID: 37181774 PMCID: PMC10171184 DOI: 10.1039/d3sc00909b] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 04/13/2023] [Indexed: 05/16/2023] Open
Abstract
DFT-Calculations predict that a low-valent complex (BDI)Mg-Ca(BDI) with bulky β-diketiminate (BDI) ligands is thermodynamically stable. It was attempted to isolate such a complex by salt-metathesis between [(DIPePBDI*)Mg-Na+]2 and [(DIPePBDI)CaI]2 (DIPePBDI = HC[C(Me)N-DIPeP]2; DIPePBDI* = HC[C(tBu)N-DIPeP]2; DIPeP = 2,6-CH(Et)2-phenyl). Whereas in alkane solvents no reaction was observed, salt-metathesis in C6H6 led to immediate C-H activation of benzene to give (DIPePBDI*)MgPh and (DIPePBDI)CaH, the latter crystallizing as a THF-solvated dimer [(DIPePBDI)CaH·THF]2. Calculations suggest reduction and insertion of benzene in the Mg-Ca bond. The activation enthalpy for the subsequent decomposition of C6H62- into Ph- and H- is only 14.4 kcal mol-1. Repeating this reaction in the presence of naphthalene or anthracene led to heterobimetallic complexes in which naphthalene2- or anthracene2- anions are sandwiched between (DIPePBDI*)Mg+ and (DIPePBDI)Ca+ cations. These complexes slowly decompose to their homometallic counterparts and further decomposition products. Complexes in which naphthalene2- or anthracene2- anions are sandwiched between two (DIPePBDI)Ca+ cations were isolated. The low-valent complex (DIPePBDI*)Mg-Ca(DIPePBDI) could not be isolated due to its high reactivity. There is, however, strong evidence that this heterobimetallic compound is a fleeting intermediate.
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Affiliation(s)
- Jonathan Mai
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 Erlangen 91058 Germany
| | - Bastian Rösch
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 Erlangen 91058 Germany
| | - Neha Patel
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 Erlangen 91058 Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 Erlangen 91058 Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg Egerlandstraße 1 Erlangen 91058 Germany
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Buchner MR, Ćoćić D, Ivlev SI, Spang N, Müller M, Puchta R. Ligand exchange at tetra-coordinated beryllium centres. Dalton Trans 2023; 52:5287-5296. [PMID: 36988038 DOI: 10.1039/d3dt00713h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Mono and dinuclear phosphine complexes of beryllium halides [(PMe3)2BeX2], [(PMe3)BeX2]2 and [(PCy3)BeX2]2 (X = Cl, Br, I) were synthesised and characterised via NMR and IR spectroscopy as well as single crystal X-ray diffraction experiments. Dissociation and ligand exchange processes at these complexes were investigated through variable temperature NMR experiments in combination with line shape analysis and complemented by quantum chemical calculations. The PMe3 dissociation energy is smallest in [(PMe3)2BeCl2], while PMe3 exchange is similar in energy in all mononuclear [(PMe3)2BeX2] complexes and follows an interchange mechanism. While [(PMe3)BeX2]2 dissociates homolytically, [(PCy3)BeX2]2 cleaves one phosphine ligand. These distinctive dissociation processes account for the different chemical behaviour of these complexes.
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Affiliation(s)
- Magnus R Buchner
- Anorganische Chemie, Nachwuchsgruppe Hauptgruppenmetallchemie, Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
| | - Dušan Ćoćić
- Anorganische und Metallorganische Chemie, Department Chemie und Pharmazie, Friedrich-Alexander-Universität, Egerlandstraße 1, 91058 Erlangen, Germany.
- Faculty of Science, University of Kragujevac, Radoja Domanovića 12, P. O. Box 60, 34000 Kragujevac, Serbia
| | - Sergei I Ivlev
- Anorganische Chemie, Nachwuchsgruppe Hauptgruppenmetallchemie, Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
| | - Nils Spang
- Anorganische Chemie, Nachwuchsgruppe Hauptgruppenmetallchemie, Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
| | - Matthias Müller
- Anorganische Chemie, Nachwuchsgruppe Hauptgruppenmetallchemie, Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
| | - Ralph Puchta
- Anorganische und Metallorganische Chemie, Department Chemie und Pharmazie, Friedrich-Alexander-Universität, Egerlandstraße 1, 91058 Erlangen, Germany.
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14
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Buchner MR, Müller M. Handling Beryllium, the Safe Way. ACS CHEMICAL HEALTH & SAFETY 2023. [DOI: 10.1021/acs.chas.3c00003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Affiliation(s)
- Magnus R. Buchner
- Fachbereich Chemie, Philipps-Universität Marburg, 35032 Marburg, Germany
| | - Matthias Müller
- Fachbereich Chemie, Philipps-Universität Marburg, 35032 Marburg, Germany
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Boronski JT, Thomas-Hargreaves LR, Ellwanger MA, Crumpton AE, Hicks J, Bekiş DF, Aldridge S, Buchner MR. Inducing Nucleophilic Reactivity at Beryllium with an Aluminyl Ligand. J Am Chem Soc 2023; 145:4408-4413. [PMID: 36786728 PMCID: PMC9983009 DOI: 10.1021/jacs.3c00480] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The reactions of anionic aluminium or gallium nucleophiles {K[E(NON)]}2 (E = Al, 1; Ga, 2; NON = 4,5-bis(2,6-diisopropylanilido)-2,7-ditert-butyl-9,9-dimethylxanthene) with beryllocene (BeCp2) led to the displacement of one cyclopentadienyl ligand at beryllium and the formation of compounds containing Be-Al or Be-Ga bonds (NON)EBeCp (E = Al, 3; Ga, 4). The Be-Al bond in the beryllium-aluminyl complex [2.310(4) Å] is much shorter than that found in the small number of previous examples [2.368(2) to 2.432(6) Å], and quantum chemical calculations suggest the existence of a non-nuclear attractor (NNA) for the Be-Al interaction. This represents the first example of a NNA for a heteroatomic interaction in an isolated molecular complex. As a result of this unusual electronic structure and the similarity in the Pauling electronegativities of beryllium and aluminium, the charge at the beryllium center (+1.39) in 3 is calculated to be less positive than that of the aluminium center (+1.88). This calculated charge distribution suggests the possibility for nucleophilic behavior at beryllium and correlates with the observed reactivity of the beryllium-aluminyl complex with N,N'-diisopropylcarbodiimide─the electrophilic carbon center of the carbodiimide undergoes nucleophilic attack by beryllium, thereby yielding a beryllium-diaminocarbene complex.
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Affiliation(s)
- Josef T. Boronski
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom;,
| | | | - Mathias A. Ellwanger
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom;
| | - Agamemnon E. Crumpton
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom;
| | - Jamie Hicks
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom;
| | - Deniz F. Bekiş
- Fachbereich
Chemie, Philipps-Universität Marburg, Marburg 35037, Germany
| | - Simon Aldridge
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, United Kingdom;,
| | - Magnus R. Buchner
- Fachbereich
Chemie, Philipps-Universität Marburg, Marburg 35037, Germany,
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Gimferrer M, Danés S, Vos E, Yildiz CB, Corral I, Jana A, Salvador P, Andrada DM. Reply to the 'Comment on "The oxidation state in low-valent beryllium and magnesium compounds"' by S. Pan and G. Frenking, Chem. Sci., 2022, 13, DOI: 10.1039/D2SC04231B. Chem Sci 2023; 14:384-392. [PMID: 36687341 PMCID: PMC9811512 DOI: 10.1039/d2sc05769g] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 11/21/2022] [Indexed: 12/23/2022] Open
Abstract
A recent article by Pan and Frenking challenges our assignment of the oxidation state of low valent group 2 compounds. With this reply, we show that our assignment of Be(+2) and Mg(+2) oxidation states in Be(cAACDip)2 and Mg(cAACDip)2 is fully consistent with our data. Some of the arguments exposed by Pan and Frenking were based on visual inspection of our figures, rather than a thorough numerical analysis. We discuss with numerical proof that some of the statements made by the authors concerning our reported data are erroneous. In addition, we provide further evidence that the criterion of the lowest orbital interaction energy in the energy decomposition analysis (EDA) method is unsuitable as a general tool to assess the valence state of the fragments. Other indicators based on natural orbitals for chemical valence (NOCV) deliver a more reliable bonding picture. We also emphasize the importance of using stable wavefunctions for any kind of analysis, including EDA.
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Affiliation(s)
- Martí Gimferrer
- Departament de Química, Institut de Química Computacional i Catàlisi, Universitat de Gironac/M. Aurelia Capmany 6917003 GironaSpain
| | - Sergi Danés
- Departament de Química, Institut de Química Computacional i Catàlisi, Universitat de Gironac/M. Aurelia Capmany 6917003 GironaSpain,General and Inorganic Chemistry Department, University of SaarlandCampus C4.166123 SaarbrueckenGermany
| | - Eva Vos
- Departamento de Química, Universidad Autónoma de MadridC/Francisco Tomás y Valiente 728049 Cantoblanco MadridSpain
| | - Cem B. Yildiz
- Department of Medicinal and Aromatic Plants, Aksaray UniversityHacilar Harmani 268100 AksarayTurkey
| | - Inés Corral
- Departamento de Química, Universidad Autónoma de MadridC/Francisco Tomás y Valiente 728049 Cantoblanco MadridSpain
| | - Anukul Jana
- Tata Institute of Fundamental Research HyderabadGopanpally500046 HyderabadTelanganaIndia
| | - Pedro Salvador
- Departament de Química, Institut de Química Computacional i Catàlisi, Universitat de Gironac/M. Aurelia Capmany 6917003 GironaSpain
| | - Diego M. Andrada
- General and Inorganic Chemistry Department, University of SaarlandCampus C4.166123 SaarbrueckenGermany
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