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Multem AJH, Delaney AR, Kroeger AA, Coote ML, Colebatch AL. Utilising a Proton-Responsive 1,8-Naphthyridine Ligand for the Synthesis of Bimetallic Palladium and Platinum Complexes. Chem Asian J 2023:e202301071. [PMID: 38161148 DOI: 10.1002/asia.202301071] [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: 11/29/2023] [Revised: 12/20/2023] [Accepted: 12/25/2023] [Indexed: 01/03/2024]
Abstract
We present four proton-responsive palladium and platinum complexes, [MCl2 (R PONNHO)] (M=Pd, Pt; R=i Pr, t Bu) synthesised by complexation of PdCl2 or PtCl2 (COD) with the 1,8-naphthyridine ligand R PONNHO. Deprotonation of [MCl2 (tBu PONNHO)] switches ligand coordination from mono- to dinucleating, offering a synthetic pathway to bimetallic PdII and PtII complexes [M2 Cl2 (tBu PONNO)2 ]. Two-electron reduction gives planar MI -MI complexes [M2 (tBu PONNO)2 ] (M=Pd, Pt) containing a metal-metal bond. In contrast to the related nickel system that forms a metallophosphorane [Ni2 (tBu PONNOPONNO)], an unusual phosphinite binding mode is observed in [M2 (tBu PONNO)2 ] containing close phosphinite-naphthyridinone P⋅⋅⋅O interactions, which is investigated spectroscopically, crystallographically and computationally. The presented proton-responsive and structurally-responsive R PONNHO and bimetallic R PONNO complexes offer a novel platform for future explorations of metal-ligand and metal-metal cooperativity with palladium and platinum.
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Affiliation(s)
- Arie J H Multem
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Andie R Delaney
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Asja A Kroeger
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia, 5042, Australia
| | - Michelle L Coote
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia, 5042, Australia
| | - Annie L Colebatch
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
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2
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Delaney AR, Kroeger AA, Coote ML, Colebatch AL. Oxidative Addition and β-Hydride Elimination by a Macrocyclic Dinickel Complex: Observing Bimetallic Elementary Reactions. Chemistry 2023; 29:e202302366. [PMID: 37641804 DOI: 10.1002/chem.202302366] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023]
Abstract
The dinickel(I) complex Ni2 (tBu PONNOPONNO), featuring a planar macrocyclic diphosphoranide ligand tBu PONNOPONNO, offers a unique architectural platform for observing bimetallic elementary reactions. Oxidative addition reactions of alkyl halides produce dinickel(II) complexes of the type Ni2 (μ-R)(μ-X)(tBu PONNOPONNO). However, when R=Et β-hydride elimination is observed to form a dinickel monohydride, with the rate dependent on the nature of X. DFT studies suggest a new mechanism for bimetallic β-hydride elimination, where the rate dependence arises from the steric pressure imposed by the X group on the opposing trans face of the dinickel macrocycle. This work enhances understanding of bimetallic elementary reactions, particularly β-hydride elimination, which have not been well-explored for dinuclear systems.
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Affiliation(s)
- Andie R Delaney
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Asja A Kroeger
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia, 5042, Australia
| | - Michelle L Coote
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia, 5042, Australia
| | - Annie L Colebatch
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
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3
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Lin XC, Cui YS, Xie SJ, Chen DP, Zhai DD, Shi ZJ. Jellyfish-type Dinuclear Hafnium Azido Complexes: Synthesis and Reactivity. Chem Asian J 2023; 18:e202300659. [PMID: 37700430 DOI: 10.1002/asia.202300659] [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: 08/02/2023] [Accepted: 09/11/2023] [Indexed: 09/14/2023]
Abstract
Di- and multinuclear hafnium complexes bridged by ligands have been rarely reported. In this article, a novel 3,5-disubstituted pyrazolate-bridged ligand LH5 with two [N2 N]2- -type chelating side arms was designed and synthesized, which supported a series of dinuclear hafnium complexes. Dinuclear hafnium azides [LHf2 (μ-1,1-N3 )2 (N3 )2 ][Na(THF)4 ] 3 and [LHf2 (μ-1,1-N3 )2 (N3 )2 ][Na(2,2,2-Kryptofix)] 4 were further synthesized and structurally characterized, featuring two sets of terminal and bridging azido ligands like jellyfishes. The reactivity of 3 under reduction conditions was conducted, leading to a formation of a tetranuclear hafnium imido complex [L1 Hf2 (μ1 -NH)(N3 ){μ2 -K}]2 5. DFT calculations revealed that the mixed imido azide 5 was generated via an intramolecular C-H insertion from a putative dinuclear HfIV -nitridyl intermediate.
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Affiliation(s)
- Xin-Cheng Lin
- Department of Chemistry, Fudan University, Shanghai, 200433, P. R. China
| | - Yun-Shu Cui
- Department of Chemistry, Fudan University, Shanghai, 200433, P. R. China
| | - Si-Jun Xie
- Department of Chemistry, Fudan University, Shanghai, 200433, P. R. China
| | - Dong-Ping Chen
- Department of Chemistry, Fudan University, Shanghai, 200433, P. R. China
| | - Dan-Dan Zhai
- Department of Chemistry, Fudan University, Shanghai, 200433, P. R. China
| | - Zhang-Jie Shi
- Department of Chemistry, Fudan University, Shanghai, 200433, P. R. China
- State Key Laboratory of Organometallic Chemistry, SIOC, CAS, Shanghai, 200032, P. R. China
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4
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Delaney AR, Yu LJ, Doan V, Coote ML, Colebatch AL. Bimetallic Nickel Complexes Supported by a Planar Macrocyclic Diphosphoranide Ligand. Chemistry 2023; 29:e202203940. [PMID: 36545819 DOI: 10.1002/chem.202203940] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 12/20/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022]
Abstract
Metal-metal cooperativity is emerging as an important strategy in catalysis. This requires appropriate ligand scaffolds that can support two metals in close proximity. Here we report nickel-promoted formation of a dinucleating planar macrocyclic ligand that can support bimetallic dinickel(II) and dinickel(I) complexes. Reaction outcomes can be tuned by variation of the substituents and reaction conditions to favour dinucleating macrocyclic, mononucleating macrocyclic or conventional pincer architectures.
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Affiliation(s)
- Andie R Delaney
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Li-Juan Yu
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Vincent Doan
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Michelle L Coote
- Institute for Nanoscale Science & Technology, Flinders University, Adelaide, South Australia, 5042, Australia
| | - Annie L Colebatch
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
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5
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Theoretical study of nickel-catalyzed hydroalkylation of 3-pyrrolines: Origin of ligand-controlled regioselectivity. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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6
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Ott JC, Bürgy D, Guan H, Gade LH. 3d Metal Complexes in T-shaped Geometry as a Gateway to Metalloradical Reactivity. Acc Chem Res 2022; 55:857-868. [PMID: 35164502 DOI: 10.1021/acs.accounts.1c00737] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
ConspectusLow-valent, low-coordinate 3d metal complexes represent a class of extraordinarily reactive compounds that can act as reagents and catalysts for challenging bond-activation reactions. The pursuit of these electron-deficient metal complexes in low oxidation states demands ancillary ligands capable of providing not only energetic stabilization but also sufficiently high steric bulk at the metal center. From this perspective, pincer ligands are particularly advantageous, as their prearranged, meridional coordination mode scaffolds the active center while the substituents of the peripheral donor atoms provide effective steric shielding for the coordination sphere. In a T-shaped geometry, the transition metal complexes possess a precisely defined vacant coordination site, which, combined with the often observed high-spin electron configuration, exhibits unusually high selectivity of these compounds with respect to one-electron redox chemistry. In light of the intractable reaction pathways typically observed with related electronically unsaturated 3d transition metal complexes, the pincer coordination mode enables the isolation of low-valent compounds with more controlled and unique reactivity. We have thus investigated a series of T-shaped metal(I) complexes using three different types of pincer ligands, which may be regarded as "metalloradicals" due to their selectively exposed unpaired electrons.These compounds display remarkably high thermal stability and represent rarely observed "naked" monovalent metal species featuring both monomeric and dimeric structures. Extensive reactivity studies using various organic substrates highlight a strong tendency of these paramagnetic compounds to undergo one-electron oxidation, leading to the isolation of a plethora of metal(II) species with reduced organic ligands as unusual structural elements. The exploration of C2 symmetric T-shaped Ni(I) complexes as asymmetric catalysts also shows success in enantioselective hydrodehalogenation of geminal dihalogenides. In addition, this specific class of low-valent, low-coordinate complexes can be further diversified by introducing redox-active pincer ligands or building homobimetallic systems with two T-shaped units.This Account focuses on the discussion of selected examples of iron, cobalt, and nickel pincer complexes bearing a [P,N,P] or [N,N,N] donor set; however, their electronic structure and radical-type reactivity can be broadly extended to other pincer systems. The availability of various types of pincer ligands should allow fine-tuning of the reactivity of the T-shaped complexes. Given the unprecedented reactivity observed with these compounds, we expect the studies of T-shaped 3d metal complexes to be a fertile field for advancing base metal catalysis.
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Affiliation(s)
- Jonas C. Ott
- Anorganisch-Chemisches Institut, Universität Heidelberg, 69120 Heidelberg, Germany
| | - David Bürgy
- Anorganisch-Chemisches Institut, Universität Heidelberg, 69120 Heidelberg, Germany
| | - Hairong Guan
- Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172, United States
| | - Lutz H. Gade
- Anorganisch-Chemisches Institut, Universität Heidelberg, 69120 Heidelberg, Germany
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Multireversible Redox Processes in a Self‐Assembled Nickel Pentanuclear Bis(Triple‐stranded Helicate): Structural and Spectroscopic Characterizations in the Ni
II
5
and Ni
I
Ni
II
4
Redox States. ChemElectroChem 2021. [DOI: 10.1002/celc.202100895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Jesse KA, Chang M, Filatov AS, Anderson JS. Iron(II) Complexes Featuring a Redox‐Active Dihydrazonopyrrole Ligand. Z Anorg Allg Chem 2021; 647:1415-1420. [DOI: 10.1002/zaac.202100097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Kate A. Jesse
- University of Chicago Department of Chemistry 929 E 57th St. Chicago IL 60637
| | - Mu‐Chieh Chang
- National Taiwan University Department of Chemistry No. 1, Section 4, Roosevelt Rd, Da'an District Taipei City Taiwan 10
| | | | - John S. Anderson
- University of Chicago Department of Chemistry 929 E 57th St. Chicago IL 60637
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Ott JC, Wadepohl H, Gade LH. Metalloradical Reactivity, Charge Transfer, and Atom Abstractions in a T-Shaped Iron(I) Complex. Inorg Chem 2021; 60:3927-3938. [DOI: 10.1021/acs.inorgchem.0c03724] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Jonas C. Ott
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, 69120 Heidelberg, Germany
| | - Hubert Wadepohl
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, 69120 Heidelberg, Germany
| | - Lutz H. Gade
- Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, 69120 Heidelberg, Germany
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Duan P, Schulz RA, Römer A, Van Kuiken BE, Dechert S, Demeshko S, Cutsail GE, DeBeer S, Mata RA, Meyer F. Ligand Protonation Triggers H 2 Release from a Dinickel Dihydride Complex to Give a Doubly "T"-Shaped Dinickel(I) Metallodiradical. Angew Chem Int Ed Engl 2021; 60:1891-1896. [PMID: 33026170 PMCID: PMC7894169 DOI: 10.1002/anie.202011494] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Indexed: 12/12/2022]
Abstract
The dinickel(II) dihydride complex (1K ) of a pyrazolate-based compartmental ligand with β-diketiminato (nacnac) chelate arms (L- ), providing two pincer-type {N3 } binding pockets, has been reported to readily eliminate H2 and to serve as a masked dinickel(I) species. Discrete dinickel(I) complexes (2Na , 2K ) of L- are now synthesized via a direct reduction route. They feature two adjacent T-shaped metalloradicals that are antiferromagnetically coupled, giving an S=0 ground state. The two singly occupied local d x 2 - y 2 type magnetic orbitals are oriented into the bimetallic cleft, enabling metal-metal cooperative 2 e- substrate reductions as shown by the rapid reaction with H2 or O2 . X-ray crystallography reveals distinctly different positions of the K+ in 1K and 2K , suggesting a stabilizing interaction of K+ with the dihydride unit in 1K . H2 release from 1K is triggered by peripheral γ-C protonation at the nacnac subunits, which DFT calculations show lowers the barrier for reductive H2 elimination from the bimetallic cleft.
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Affiliation(s)
- Peng‐Cheng Duan
- Universität GöttingenInstitut für Anorganische ChemieTammannstrasse 437077GöttingenGermany
- Center for Catalysis and Florida Center for Heterocyclic CompoundsDepartment of ChemistryUniversity of FloridaGainesvilleFL32611-7200USA
| | | | - Anton Römer
- Universität GöttingenInstitut für Physikalische ChemieTammannstrasse 637077GöttingenGermany
| | - Benjamin E. Van Kuiken
- Max Planck Institute for Chemical Energy Conversion (MPI-CEC)Stiftstrasse 34–3645470Mülheim an der RuhrGermany
- European XFELHolzkoppel 422869SchenefeldGermany
| | - Sebastian Dechert
- Universität GöttingenInstitut für Anorganische ChemieTammannstrasse 437077GöttingenGermany
| | - Serhiy Demeshko
- Universität GöttingenInstitut für Anorganische ChemieTammannstrasse 437077GöttingenGermany
| | - George E. Cutsail
- Max Planck Institute for Chemical Energy Conversion (MPI-CEC)Stiftstrasse 34–3645470Mülheim an der RuhrGermany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion (MPI-CEC)Stiftstrasse 34–3645470Mülheim an der RuhrGermany
| | - Ricardo A. Mata
- Universität GöttingenInstitut für Physikalische ChemieTammannstrasse 637077GöttingenGermany
| | - Franc Meyer
- Universität GöttingenInstitut für Anorganische ChemieTammannstrasse 437077GöttingenGermany
- Universität GöttingenInternational Center for Advanced Studies of Energy Conversion (ICASEC)Tammannstrasse 637077GöttingenGermany
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