1
|
Kumar S, Singh D, Rit A. Cooperativity between metal centers in homobimetallic Pd II-NHC complexes: catalytic potential towards hydrodefluorination. Chem Commun (Camb) 2024; 60:7761-7764. [PMID: 38973622 DOI: 10.1039/d4cc02185a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
Among the several unsymmetrical bis-NHC derived distinct homo-bimetallic and mono-NHC supported PdII complexes studied here (1-5), the bimetallic complex 1 was noted to be the most effective catalyst for the challenging hydrodefluorination. The electron richness of the metal centers and the synergistic cooperation between the PdII centers (cooperativity index, ɑ = 8.67) have been recognized to be the deciding factor for its better activity.
Collapse
Affiliation(s)
- Shashi Kumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
| | - Dushyant Singh
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
| | - Arnab Rit
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
| |
Collapse
|
2
|
Knighton RC, Pope SJA. Synthesis and luminescent properties of hetero-bimetallic and hetero-trimetallic Ru(II)/Au(I) or Ir(III)/Au(I) complexes. Dalton Trans 2024; 53:4165-4174. [PMID: 38318847 DOI: 10.1039/d3dt03690a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
A series of Ru(II) and Ir(III) based photoluminescent complexes were synthesised that incorporate an ancillary 2,2'-bipyridine ligand adorned with either one or two pendant N-methyl imidazolium groups. These complexes have been fully characterised by an array of spectroscopic and analytical techniques. One Ir(III) example was unequivocally structurally characterised in the solid state using single crystal X-ray diffraction confirming the proposed formulation and coordination sphere. These complexes were then transformed into their heterometallic, Au(I)-containing, analogues in two steps to yield either bi- or trimetallic complexes that integrate {Au(PPh3)}+ units. X-ray diffraction was used to corroborate the solid state structure of the hetero bimetallic complex, based upon a Ru(II)-Au(I) species. The heterometallic complexes all displayed red photoluminescent features (λem = 616-629 nm) that were consistent with the parent Ru(II) or Ir(III) lumophores in each case. The modulation of the emission from the Ru(II)-Au(I) complexes was much more strongly evident than for the Ir(III)-Au(I) analogues, which is ascribed to the inherent differences in the specific triplet excited state character of the emitting states within each heterometallic species.
Collapse
Affiliation(s)
- Richard C Knighton
- School of Chemistry, Cardiff University, Main Building, Cardiff, CF10 3AT, UK.
| | - Simon J A Pope
- School of Chemistry, Cardiff University, Main Building, Cardiff, CF10 3AT, UK.
| |
Collapse
|
3
|
Tarifa L, Geer AM, Asensio L, López JA, Ciriano MA, Tejel C. Redox-Transmetalation Reactions: Easy Access to Homo- and Heterodimetallic d 8,d 10 Complexes. Inorg Chem 2023; 62:19421-19432. [PMID: 37988130 DOI: 10.1021/acs.inorgchem.3c02200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
The ability of the imine PyCH═N-CH2Py (Py = 2-pyridyl, bpi) to behave as a heteroditopic ligand, which is suitable for creating two separate compartments to host metals in different oxidation states, has been developed by studying the reactions of the mixed-valence complexes [(cod)M-Ι(μ-bpi)MΙ(cod)] (M = Rh, Ir) with [M'(Cl)2(PPh3)2] (M' = Pd, Ni). The results depend on the molar ratio of the reagents used (1:1 or 1:2) to give the heterometallic complexes {d10-M',d8-M}-[(PPh3)(Cl)M'0(μ-bpi)MΙ(cod)] (Pd,Rh, 4; Pd,Ir, 5; Ni,Rh, 8; Ni,Ir, 9) and the two-electron mixed-valent compounds [(PPh3)(Cl)M'0(μ-bpi)M'ΙΙ(Cl)] (M' = Ni, 10; Pd, 11), respectively. A redox process occurs in the replacement of the low-valent [(cod)M-I] fragment, whereas the exchange of the [(cod)MI] fragment is redox-neutral. The metal with a d8 configuration in the products exhibits a square-planar geometry coordinated to two (Rh/Ir) or three (Ni/Pd) nitrogen atoms of the bridging bpi ligand. Conversely, the metal with a d10 configuration adopts trigonal-planar geometries, π-bonded to the imine C═N bond. The isolated complexes 4/5 and 10/11, along with the hypothetical heterometallic Pd,Ni compound (12), were studied by DFT methods. Additionally, the T-shaped moiety 'M'ΙΙ(PPh3)(Cl)(η1-CH-N(bpi))', stabilized by a secondary γ-agostic interaction, and the 'M'II(Cl)(κ3N-bpi)' fragment was found to be accessible redoxomers of complexes 10 and 11 by DFT calculations.
Collapse
Affiliation(s)
- Luis Tarifa
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Ana M Geer
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Laura Asensio
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - José A López
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Miguel A Ciriano
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Cristina Tejel
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| |
Collapse
|
4
|
Kumar S, Patra DK, Rit A. Heterobimetallic Complexes Bridged by an Unsymmetrical Bis(NHC) Ligand: Study of Enhanced Catalytic Activity in Tandem Transformations and Understanding of Cooperativity between the Metal Centers. Chemistry 2023; 29:e202302180. [PMID: 37702918 DOI: 10.1002/chem.202302180] [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: 07/08/2023] [Revised: 09/12/2023] [Accepted: 09/12/2023] [Indexed: 09/14/2023]
Abstract
The bis(azolium) salt [L1-H2 ]Br2 was found to serve as a suitable platform for accessing the heterobimetallic IrIII -M (M=PdII /AuI ) and PdII -IrIII complexes. Initially, selective mono-metalation of [L1-H2 ]Br2 yielded an orthometalated IrIII - or non-orthometalated PdII -complex. Sequential metalation of the mono-IrIII complex resulted in the formation of heterobimetallic IrIII -PdII /AuI complexes. Similarly, a distinct heterobimetallic PdII -IrIII complex was synthesized starting from the mono-PdII complex. Further, the corresponding homobimetallic IrIII -IrIII and PdII -PdII complexes were directly obtained from [L1-H2 ]Br2 . Additionally, monometallic PdII and IrIII analogues were synthesized from [L2-H]Br and [L3-H]Br, respectively. The heterobimetallic IrIII -PdII and PdII -IrIII complexes were then evaluated as catalysts in various one-pot tandem catalytic reactions in which they demonstrated superior activity than the mixtures of both their corresponding homobimetallic IrIII -IrIII /PdII -PdII and monometallic IrIII /PdII counterparts, under the constant concentrations of metal centers. Moreover, while comparing complexes IrIII -PdII and PdII -IrIII , the former exhibits higher activity in all the studied reactions. All these findings suggest the presence of some form of cooperativity between the two metal centers (Ir and Pd) connected by a single ligand framework in IrIII -PdII and PdII -IrIII complex, with IrIII -PdII displaying better cooperativity that has been validated by electrochemical, NMR, and DFT studies.
Collapse
Affiliation(s)
- Shashi Kumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Deeptesh K Patra
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600036, India
| | - Arnab Rit
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600036, India
| |
Collapse
|
5
|
Fickenscher Z, Hey-Hawkins E. Added Complexity!-Mechanistic Aspects of Heterobimetallic Complexes for Application in Homogeneous Catalysis. Molecules 2023; 28:molecules28104233. [PMID: 37241974 DOI: 10.3390/molecules28104233] [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: 04/29/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 05/28/2023] Open
Abstract
Inspired by multimetallic assemblies and their role in enzyme catalysis, chemists have developed a plethora of heterobimetallic complexes for application in homogeneous catalysis. Starting with small heterobimetallic complexes with σ-donating and π-accepting ligands, such as N-heterocyclic carbene and carbonyl ligands, more and more complex systems have been developed over the past two decades. These systems can show a significant increase in catalytic activity compared with their monometallic counterparts. This increase can be attributed to new reaction pathways enabled by the presence of a second metal center in the active catalyst. This review focuses on mechanistic aspects of heterobimetallic complexes in homogeneous catalysis. Depending on the type of interaction of the second metal with the substrates, heterobimetallic complexes can be subdivided into four classes. Each of these classes is illustrated with multiple examples, showcasing the versatility of both, the types of interactions possible, and the reactions accessible.
Collapse
Affiliation(s)
- Zeno Fickenscher
- Institute of Inorganic Chemistry, Universität Leipzig, Johannisallee 29, D-04103 Leipzig, Germany
| | - Evamarie Hey-Hawkins
- Institute of Inorganic Chemistry, Universität Leipzig, Johannisallee 29, D-04103 Leipzig, Germany
| |
Collapse
|
6
|
Majumder A, Naskar R, Roy P, Mondal B, Garai S, Maity R. A naphthalene-based heterobimetallic triazolylidene Ir III/Pd II complex: regioselective to regiospecific C-H activation, tandem catalysis and a copper-free Sonogashira reaction. Dalton Trans 2023; 52:2272-2281. [PMID: 36723111 DOI: 10.1039/d2dt03508a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Heterobimetallic complexes featuring mesoionic carbene (MIC) donor ligands are gaining enormous popularity in tandem catalysis owing to the combined action of two different metal centers during catalysis. A rare version of the heterobimetallic PdII/IrIII complex possessing a cyclometalated mesoionic carbene (MIC) ligand is presented along with the analogous homodinuclear PdII complex. A sterically controlled regiospecific cyclometalation towards the formation of a six-membered ring complex over a five-membered ring complex has been performed using a naphthalene-based bis-MIC ligand platform. The interplay between regioselective vs. regiospecific C-H bond activation for the synthesis of cyclometalated IrIII complexes has also been demonstrated using the corresponding naphthyl-derived mono-imidazolylidene ligand. Both homodinuclear PdII and heterobimetallic PdII/IrIII complexes have been characterized using standard spectroscopic techniques including 1H, 13C{1H}, 2D correlation NMR spectroscopy and ESI mass spectrometry. The structure of the cyclometalated heterobimetallic complex has been established by single crystal XRD. The heterobimetallic complex has been employed as a pre-catalyst in the tandem Suzuki-Miyaura/transfer hydrogenation reaction and the homobimetallic PdII complex has been successfully employed as a catalyst in both the Sonogashira coupling and α-arylation of 1-methyl-2-oxindole.
Collapse
Affiliation(s)
- Adhir Majumder
- Department of Chemistry, University of Calcutta, Kolkata, West Bengal, 700009, India.
| | - Rajat Naskar
- Department of Chemistry, University of Calcutta, Kolkata, West Bengal, 700009, India.
| | - Pallabi Roy
- Department of Chemistry, University of Calcutta, Kolkata, West Bengal, 700009, India.
| | - Bhaskar Mondal
- Department of Chemistry, University of Calcutta, Kolkata, West Bengal, 700009, India.
| | - Somenath Garai
- Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi 221 005, Uttar Pradesh, India
| | - Ramananda Maity
- Department of Chemistry, University of Calcutta, Kolkata, West Bengal, 700009, India.
| |
Collapse
|
7
|
Non-Noble-Metal Mono and Bimetallic Composites for Efficient Electrocatalysis of Phosphine Oxide and Acetylene C-H/P-H Coupling under Mild Conditions. Int J Mol Sci 2023; 24:ijms24010765. [PMID: 36614210 PMCID: PMC9821134 DOI: 10.3390/ijms24010765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 01/03/2023] Open
Abstract
The present work describes an efficient reaction of electrochemical phosphorylation of phenylacetylene controlled by the composition of catalytic nanoparticles based on non-noble-metals. The sought-after products are produced via the simple synthetic protocol based on room temperature, atom-economical reactions, and silica nanoparticles (SNs) loaded by one or two d-metal ions as nanocatalysts. The redox and catalytic properties of SNs can be tuned with a range of parameters, such as compositions of the bimetallic systems, their preparation method, and morphology. Monometallic SNs give phosphorylated acetylene with retention of the triple bond, and bimetallic SNs give a bis-phosphorylation product. This is the first example of acetylene and phosphine oxide C-H/P-H coupling with a regenerable and recyclable catalyst.
Collapse
|
8
|
Illam PM, Tiwari CS, Rit A. Towards new coordination modes of 1,2,3-triazolylidene: controlled by the nature of the 1 st metalation in a heteroditopic bis-NHC ligand. Chem Sci 2022; 13:13387-13392. [PMID: 36507188 PMCID: PMC9682892 DOI: 10.1039/d2sc05024b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/20/2022] [Indexed: 12/15/2022] Open
Abstract
An unusual effect of the nature of the first metal coordination of a heteroditopic N-heterocyclic carbene ligand (L2) towards the coordination behavior of 1,2,3-tzNHC is explored. The first metal coordination at the ImNHC site (complexes 3 and 4) was noted to substantially influence the electronics of the 1,2,3-triazolium moiety leading to an unprecedented chemistry of this MIC donor. Along this line, the RhIII/IrIII-orthometalation in complexes 4 makes the triazolium C4-H more downfield shifted than C5-H, whereas a reverse trend, although to a lesser extent, is observed in the case of the non-chelated PdII-coordination. This difference in behavior assisted us to achieve the selective activation of triazole C4/C5 positions, not observed before, as supported by the isolation of the homo- and hetero-bimetallic complexes, 5, 6 and 7-9via C5- and C4-metalation, respectively. Furthermore, the %V bur calculations eliminate any considerable steric influence and the DFT studies strongly support the selectivity observed during bimetalation.
Collapse
Affiliation(s)
| | | | - Arnab Rit
- Department of Chemistry, Indian Institute of Technology MadrasChennai 600036India
| |
Collapse
|
9
|
Nishad RC, Kumar S, Rit A. Self‐Assembly of a Bis‐NHC Ligand and Coinage Metal Ions: Unprecedented Metal‐Driven Chemistry between the Tri‐ and Tetranuclear Species. Angew Chem Int Ed Engl 2022; 61:e202206788. [DOI: 10.1002/anie.202206788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Rajeev C. Nishad
- Department of Chemistry Indian Institute of Technology Madras Chennai 600036 India
| | - Shashi Kumar
- Department of Chemistry Indian Institute of Technology Madras Chennai 600036 India
| | - Arnab Rit
- Department of Chemistry Indian Institute of Technology Madras Chennai 600036 India
| |
Collapse
|
10
|
Nishad RC, Kumar S, Rit A. Self‐Assembly of a Bis‐NHC Ligand and Coinage Metal Ions: Unprecedented Metal Driven Chemistry between the Tri‐ and Tetranuclear Species. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206788] [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)
- Rajeev C. Nishad
- Indian Institute of Technology Madras Department of Chemistry INDIA
| | - Shashi Kumar
- Indian Institute of Technology Madras Department of Chemistry INDIA
| | - Arnab Rit
- Indian Institute of Technology, Madras Department of Chemistry Sardar patel Road 600036 Chennai INDIA
| |
Collapse
|
11
|
Wen Z, Maisonhaute E, Zhang Y, Roland S, Sollogoub M. Janus-type homo-, hetero- and mixed valence-bimetallic complexes with one metal encapsulated in a cyclodextrin. Chem Commun (Camb) 2022; 58:4516-4519. [PMID: 35302572 DOI: 10.1039/d2cc00219a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bis-azolium salts with one azolium capping a perbenzylated α-cyclodextrin have been designed to generate Janus-type bimetallic complexes with various combinations of copper, silver, gold or palladium salts. Encapsulation of one metal center inside the cavity allowed (trans)metalation and oxidation reactions to be controlled at selected positions. In particular, it was possible to oxidize AuI into AuIII selectively on the position outside the cavity of the cyclodextrin on the bis-AuI Janus complex.
Collapse
Affiliation(s)
- Zhonghang Wen
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM) UMR 8232. 4, Place Jussieu, Paris 75005, France.
| | - Emmanuel Maisonhaute
- Sorbonne Université, CNRS, Laboratoire Interfaces et Systèmes Electrochimiques (LISE) UMR 8235. 4, place Jussieu, Paris 75005, France
| | - Yongmin Zhang
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM) UMR 8232. 4, Place Jussieu, Paris 75005, France.
| | - Sylvain Roland
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM) UMR 8232. 4, Place Jussieu, Paris 75005, France.
| | - Matthieu Sollogoub
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM) UMR 8232. 4, Place Jussieu, Paris 75005, France.
| |
Collapse
|
12
|
Kariuki BM, Platts JA, Newman PD. A hybrid bipy–NHC ligand for the construction of group 11 mixed-metal bimetallic complexes. RSC Adv 2021; 11:34170-34173. [PMID: 35497314 PMCID: PMC9042343 DOI: 10.1039/d1ra06581e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/05/2021] [Indexed: 11/25/2022] Open
Abstract
An asymmetric bipy/NHC ligand L has been used to construct Au/Au, Au/Ag and Au/Cu bimetallic complexes through prior coordination of the NHC to Au(i) and subsequent introduction of the second group 11 metal ion at the bipy donor of the hybrid ligand. The complex [Au(κC-L)2]BF4,1, has been used as the precursor for the formation of [AuAg(κ-CAu,κ2-N,N′Ag-1)2](BF4)2, 2a, [AuCu(κ-CAu,κ2-N,N′Cu-1)2](BF4)2, 2b and [AuAu′(κ-CAu/Au′,κ1-NAu/Au′-1)2](BF4)2, 3. A ditopic bipy–NHC ligand has been used to construct hetero-bimetallic complexes of the monovalent group 11 metals.![]()
Collapse
Affiliation(s)
- Benson M. Kariuki
- School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, Wales, UK
| | - James A. Platts
- School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, Wales, UK
| | - Paul D. Newman
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, Wales, UK
| |
Collapse
|