Submit to Special Issue Submit Abstract to Special Issue Review for Inorganics Propose a Special Issue

Journal Browser

► Journal Browser

Special Issue "Revealing Reaction Mechanisms in Homogeneous Transition Metal Catalysis, 2nd Edition"

Special Issue Editors
Special Issue Information
Keywords
Related Special Issue
Published Papers

A special issue of Inorganics (ISSN 2304-6740). This special issue belongs to the section "Organometallic Chemistry".

Deadline for manuscript submissions: 31 December 2023 | Viewed by 2945

Share This Special Issue

Special Issue Editors

Prof. Dr. Axel Klein

E-Mail Website
Guest Editor

Department of Chemistry, Institute of Inorganic Chemistry, University of Cologne, D-50939 Cologne, Germany
Interests: transition metal complexes (including organometallic); platinum, palladium, nickel; synthesis; electrochemistry; photophysics; spectroscopy; modelling of catalytic processes
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. S. Masoud Nabavizadeh
E-Mail Website
Guest Editor

Rashidi Laboratory of Organometallic Chemistry, Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71467-13565, Iran
Interests: organometallic chemistry; kinetic and mechanism; photophysics

Dr. Fatemeh Niroomand Hosseini
E-Mail Website
Guest Editor

Department of Chemistry, Shiraz Branch, Islamic Azad University, Shiraz 71993-37635, Iran
Interests: theoretical investigation of organometallic reactions

Special Issue Information

Dear Colleagues,

The interest in transition metal complexes as homogeneous catalysts is fueled from several sides. There are outstanding catalytic processes such as hydroformylation or the Wacker oxidation that produce important intermediates in our chemical supply chain on an industrial scale of millions of tons. At the same time, there are highly selective and efficient catalysts for gram-scale lab reactions with high valorization. Finally, when considering metalloenzymes in biochemical processes the list of homogeneous catalysts containing transition metals is long and the types of reactions they catalyze encompass any kind of chemical reaction we can think of.

For non-transition metal catalysis, the invariability of the octet rule for the involved light elements facilitates the description of the underlying mechanistic steps. For transition metals, the number of binding partners, spin and oxidation state; in other words, their electronic setting is variable and far less clear than an octet of electrons. Plausibility is very often the rationale of the mechanisms depicted in textbooks and publications, while consolidated knowledge is frequently scarce. However, with the highly sophisticated spectroscopic and analytical tools that we have in hand today and the dramatically developing quality of quantum chemical calculations, we are more and more able to obtain deep insight into catalytic mechanisms. In turn, this allows us to further optimize catalysts and catalytic reactions.

This Special Issue aims to bring together experimental, theoretical, and mixed experimental–theoretical approaches to reveal mechanisms in transition metal catalyzed organic, inorganic, organometallic, and biochemical transformations. It will focus on the role of the transition metal(s) in binding and activating substrates, transforming them and finally releasing them. This includes the beneficial/cooperating role of non-spectator ligands. Studies dedicated to providing insights into reaction mechanisms, including tracing or characterization of intermediates or modelling essential reaction steps, are welcome.

Prof. Dr. Axel Klein
Prof. Dr. S. Masoud Nabavizadeh
Dr. Fatemeh Niroomand Hosseini
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Inorganics is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

transition metal catalysis
mechanistic studies
reactive intermediates
quantum chemical calculations
in situ spectroscopy
enzyme modelling
substrate activation
cooperative catalysis
ligand design

Related Special Issue

Revealing Reaction Mechanisms in Homogeneous Transition Metal Catalysis in Inorganics (9 articles)

Published Papers (3 papers)

Download All Papers

Research

Open AccessArticle

The Fast Formation of a Highly Active Homogeneous Catalytic System upon the Soft Leaching of Pd Species from a Heterogeneous Pd/C Precursor

Alexey S. Galushko

Valentina V. Ilyushenkova

Julia V. Burykina

Ruslan R. Shaydullin

Evgeniy O. Pentsak

and

Valentine P. Ananikov

Inorganics 2023, 11(6), 260; https://doi.org/10.3390/inorganics11060260 - 19 Jun 2023

Viewed by 652

Abstract

Understanding the interface between soluble metal complexes and supported metal particles is important in order to reveal reaction mechanisms in a new generation of highly active homogeneous transition metal catalysts. In this study, we show that, in the case of palladium forming on a carbon (Pd/C) catalyst from a soluble Pd(0) complex Pd₂dba₃, the nature of deposited particles on a carbon surface turns out to be much richer than previously assumed, even if a very simple experimental procedure is utilized without the use of additional reagents and procedures. In the process of obtaining a heterogeneous Pd/C catalyst, highly active “hidden” metal centers are formed on the carbon surface, which are leached out by the solvent and demonstrate diverse reactivity in the solution phase. The results indicate that heterogeneous catalysts may naturally contain trace amounts of molecular monometallic centers of a different nature by easily transforming them to the homogeneous catalytic system. In line with a modern concept, a heterogenized homogeneous catalyst precursor was found to leach first, leaving metal nanoparticles mostly intact on the surface. In this study, we point out that the previously neglected soft leaching process contributes to high catalyst activity. The results we obtained demand for leaching to be reconsidered as a flexible tool for catalyst construction and for the rational design of highly active and selective homogeneous catalytic systems, starting from easily available heterogeneous catalyst precursors. Full article

(This article belongs to the Special Issue Revealing Reaction Mechanisms in Homogeneous Transition Metal Catalysis, 2nd Edition)

► Show Figures

Graphical abstract

Open AccessArticle

The Role of Non-Covalent Interactions in the Reactions between Palladium Hydrido Complex with Amidoarylphosphine Pincer Ligand and Brønsted Acids

Vladislava A. Kirkina

and

Inorganics 2023, 11(5), 212; https://doi.org/10.3390/inorganics11050212 - 15 May 2023

Viewed by 853

Abstract

The interaction between (PNP)PdH (1); PNP = bis(2-diisopropylphosphino-4-methylphenyl)amide and different acids (CF₃SO₃H, HBF₄∙Et₂O, fluorinated alcohols and formic acid) was studied in benzene or toluene as well as in neat alcohols by IR and NMR spectroscopies. The structures of hydrogen-bonded complexes were also optimized at the DFT/ωB97-XD/def2-TZVP level. The nitrogen atom of the amidophosphine pincer ligand readily accepts proton not only from strong Brønsted acids but from relatively weak fluorinated alcohols_. That suggests that binding to palladium(II) increases the diarylamine basicity, making it a strong base. Nevertheless, H⁺ can be taken from [(PN(H)P)PdH]⁺ (2) by pyridine or hexamethylphosphoramide (HMPA). These observations confirm the need for a shuttle base to form [(PN(H)P)PdH]⁺ (2) as the result of the heterolytic splitting of H₂ by [(PNP)Pd]⁺. At that, a stoichiometric amount of formic acid protonates a hydride ligand yielding an unstable η²-H₂ complex that rapidly converts into formate (PNP)Pd(OCHO), which loses CO₂ to restore (PNP)PdH, whereas the relatively high acid excess hampers this reaction through competitive protonation at nitrogen atom. Full article

(This article belongs to the Special Issue Revealing Reaction Mechanisms in Homogeneous Transition Metal Catalysis, 2nd Edition)

► Show Figures

Figure 1

Open AccessArticle

C–H Metalation of Terpyridine Stereoisomers with Ni(II), Pd(II), and Pt(II)

and

Inorganics 2023, 11(4), 174; https://doi.org/10.3390/inorganics11040174 - 21 Apr 2023

Viewed by 1099

Abstract

Ni(II), Pd(II), and Pt(II) complexes [M(Y-terpy)X] (X = Cl or Br) containing the tridentate N^C^N-cyclometalating 2,3′:5′,2″and 2,2′:4′,2″ stereoisomers of the well-known tridentate N^N^N ligand 2,2′:6′,2″-terpyridine (terpy) were synthesised in moderate to good yields through C–H activation. For the Pt complexes, the phenyl ethynide derivatives [Pt(Y-terpy)(C≡CPh)] were also obtained under Sonogashira conditions. In contrast to this, C^N^N cyclometalated complexes using the 2,2′:6′,3″- and 2,2′:6′4″-terpy isomers were not obtained. Comparison of the N^C^N complexes of the cyclometalated 2,3′:5′,2″- and 2,2′:4′,2″-terpy ligands with complexes [M(dpb)Cl] of the prototypical N^C^N cyclometalating ligand dpb⁻ (Hdpb = 2,6-diphenyl-pyridine) showed higher potentials for the terpy complexes for the ligand-centred reductions in line with the superior π-accepting properties of the terpy ligands compared with dpb. Metal-centred oxidations were facilitated by the dpb ligand carrying a central σ-donating phenyl group instead of a metalated pyridine moiety. The same trends were found for the long-wavelength absorptions and the derived electrochemical and optical band gaps. The lower σ-donating capacities of the cyclometalated terpy derivatives is also confirmed by a reduced trans influence in the structure of [Ni(2,3′:5′,2″-terpy)Br_0.14/OAc_0.86]. Attempts to re-crystallise some poorly soluble Pd(II) and Pt(II) complexes of this series under solvothermal conditions (HOAc) gave two structures with N-protonated cyclometalated pyridine moieties, [Pt(2,3′:5′,2″-terpyH)Cl]^.Cl and [Pd(2,3′:5′,2″-terpyH)Cl₂]. Full article

(This article belongs to the Special Issue Revealing Reaction Mechanisms in Homogeneous Transition Metal Catalysis, 2nd Edition)

► Show Figures