Submit to Inorganics Review for Inorganics Propose a Special Issue

Journal Browser

► Journal Browser

Special Issue "Photochemistry & Photophysics of Transition Metal Complexes"

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Inorganics (ISSN 2304-6740).

Deadline for manuscript submissions: closed (31 January 2020) | Viewed by 15901

Share This Special Issue

Special Issue Editors

Prof. Dr. Paul I.P. Elliott

E-Mail Website
Guest Editor

Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield, UK
Interests: photochemistry; photophysics; transition metals; complexes; triazole ligands

Dr. Paul A. Scattergood

E-Mail Website
Guest Editor

Department of Chemistry, University of Huddersfield, Queensgate, Huddersfield, UK
Interests: coordination chemistry; inorganic synthesis; photophysics; photochemistry

Special Issue Information

Dear Colleagues,

Contributions are invited for this Special Issue of Inorganics entitled “Photochemistry & Photophysics of Transition Metal Complexes”. The molecular manipulation of light remains one of the greatest challenges for the chemical sciences. For more than four decades, the optical properties and applications of transition metal element complexes has been a highly active area in inorganic chemistry. With impacts in areas from climate change mitigation to biomedical sciences, this remains a highly important theme that is at the forefront of the chemical sciences today. We therefore wish to celebrate the vibrancy and diversity of the work of the global inorganic photochemical and photophysical community in this Special Issue.

Contributions may cover any area of fundamental experimental or computational photochemistry, the photophysical properties of metal complexes, or the applications of photoactive metal complexes, including in solar catalysis, photovoltaics, light-emitting technologies, biological luminescence imaging and phototherapeutics.

Prof. Dr. Paul I.P. Elliott
Dr. Paul A. Scattergood
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

photochemistry
photophysics
complexes
transition metals
ligands

Published Papers (5 papers)

Download All Papers

Research

20 pages, 2744 KiB

Open AccessArticle

Photophysical and Biological Properties of Iridium Tetrazolato Complexes Functionalised with Fatty Acid Chains

and

Inorganics 2020, 8(4), 23; https://doi.org/10.3390/inorganics8040023 - 26 Mar 2020

Cited by 4 | Viewed by 2810

Abstract

Five cyclometalated Ir(III) tetrazolato complexes functionalised with fatty acid chains (octanoic, palmitic, stearic, palmitoleic, and oleic) have been synthesised. The fatty acids were chosen to evaluate the potential effect of the length and degree of unsaturation on the biological properties of the complexes for use as cellular imaging agents. The complexes were analysed in both organic and aqueous media to determine if the presence and nature of the fatty acid chains had a significant effect on their photophysical properties. The complexes display green–yellow emission in dichloromethane solutions with relatively long excited state decays, within the range 360–393 ns, and quantum yields between 5.4% and 6.7% (from degassed solutions). Temperature-dependent photophysical studies suggest that the emitting excited states of the complexes might be quenched by the thermal population of dark states. In water, the quantum yields drop within the range of 0.5%–2.4%, and the photophysical measurements are influenced by the variable degrees of aggregation. In general, the entire series displayed low cytotoxicity and relatively high photostability, which are favourable attributes in the design of cellular imaging agents. Images of live HeLa cells were obtained for all the complexes, but those functionalised with palmitic and stearic acids had limitations due the lower solubility conferred by the saturated aliphatic chains. The complexes were mainly detected within the endoplasmic reticulum. Full article

(This article belongs to the Special Issue Photochemistry & Photophysics of Transition Metal Complexes)

► Show Figures

Graphical abstract

13 pages, 3379 KiB

Open AccessArticle

Photophysical and Electrocatalytic Properties of Rhenium(I) Triazole-Based Complexes

and

Inorganics 2020, 8(3), 22; https://doi.org/10.3390/inorganics8030022 - 24 Mar 2020

Cited by 2 | Viewed by 3354

Abstract

A series of [Re(N^N)(CO)₃(Cl)] (N^N = diimine) complexes based on 4-(pyrid-2-yl)-1,2,3-triazole (1), 1-benzyl-4-(pyrimidin-2-yl)-1,2,3-triazole (2), and 1-benzyl-4-(pyrazin-2-yl)-1,2,3-triazole (3) diimine ligands were prepared and their photophysical and electrochemical properties were characterized. The ligand-based reduction wave is shown to be highly sensitive to the nature of the triazole-based ligand, with the peak potential shifting by up to 600 mV toward more positive potential from 1 to 3. All three complexes are phosphorescent in solution at room temperature with λ_max ranging from 540 nm (1) to 638 nm (3). Interestingly, the complexes appear to show inverted energy-gap law behaviour (τ = 43 ns for 1 versus 92 ns for 3), which is tentatively interpreted as reduced thermal accessibility of metal-centred (³MC) states from photoexcited metal to ligand charge transfer (³MLCT) states upon stabilisation of the N^N-centred lowest unoccupied molecular orbital (LUMO). The photophysical characterisation, supported by computational data, demonstrated a progressive stabilization of the LUMO from complex 1 to 3, which results in a narrowing of the HOMO–LUMO energy gap (HOMO = highest occupied molecular orbital) across the series and, correspondingly, red-shifted electronic absorption and photoluminescence spectra. The two complexes bearing pyridyl (1) and pyrimidyl (2) moieties, respectively, showed a modest ability to catalyse the electroreduction of CO₂, with a peak potential at ca. −2.3 V versus Fc/Fc⁺. The catalytic wave that is observed in the cyclic voltammograms is slightly enhanced by the addition of water as a proton source. Full article

(This article belongs to the Special Issue Photochemistry & Photophysics of Transition Metal Complexes)

► Show Figures

Figure 1

10 pages, 2556 KiB

Open AccessCommunication

On the Possible Coordination on a ³MC State Itself? Mechanistic Investigation Using DFT-Based Methods

and

Inorganics 2020, 8(2), 15; https://doi.org/10.3390/inorganics8020015 - 19 Feb 2020

Cited by 4 | Viewed by 2509

Abstract

Understanding light-induced ligand exchange processes is key to the design of efficient light-releasing prodrugs or photochemically driven functional molecules. Previous mechanistic investigations had highlighted the pivotal role of metal-centered (MC) excited states in the initial ligand loss step. The question remains whether they are equally important in the subsequent ligand capture step. This article reports the mechanistic study of direct acetonitrile coordination onto a ³MC state of [Ru(bpy)₃]²⁺, leading to [Ru(bpy)₂(κ¹-bpy)(NCMe)]²⁺ in a ³MLCT (metal-to-ligand charge transfer) state. Coordination of MeCN is indeed accompanied by the decoordination of one pyridine ring of a bpy ligand. As estimated from Nudged Elastic Band calculations, the energy barrier along the minimum energy path is 20 kcal/mol. Interestingly, the orbital analysis conducted along the reaction path has shown that creation of the metallic vacancy can be achieved by reverting the energetic ordering of key dσ* and bpy-based π* orbitals, resulting in the change of electronic configuration from ³MC to ³MLCT. The approach of the NCMe lone pair contributes to destabilizing the dσ* orbital by electrostatic repulsion. Full article

(This article belongs to the Special Issue Photochemistry & Photophysics of Transition Metal Complexes)

► Show Figures

Graphical abstract

11 pages, 1882 KiB

Open AccessArticle

Excited-State Relaxation in Luminescent Molybdenum(0) Complexes with Isocyanide Chelate Ligands

Patrick Herr

and

Oliver S. Wenger

Inorganics 2020, 8(2), 14; https://doi.org/10.3390/inorganics8020014 - 17 Feb 2020

Cited by 6 | Viewed by 3254

Abstract

Diisocyanide ligands with a m-terphenyl backbone provide access to Mo⁰ complexes exhibiting the same type of metal-to-ligand charge transfer (MLCT) luminescence as the well-known class of isoelectronic Ru^II polypyridines. The luminescence quantum yields and lifetimes of the homoleptic tris(diisocyanide) Mo⁰ complexes depend strongly on whether methyl- or tert-butyl substituents are placed in α-position to the isocyanide groups. The bulkier tert-butyl substituents lead to a molecular structure in which the three individual diisocyanides ligated to one Mo⁰ center are interlocked more strongly into one another than the ligands with the sterically less demanding methyl substituents. This rigidification limits the distortion of the complex in the emissive excited-state, causing a decrease of the nonradiative relaxation rate by one order of magnitude. Compared to Ru^II polypyridines, the molecular distortions in the luminescent ³MLCT state relative to the electronic ground state seem to be smaller in the Mo⁰ complexes, presumably due to delocalization of the MLCT-excited electron over greater portions of the ligands. Temperature-dependent studies indicate that thermally activated nonradiative relaxation via metal-centered excited states is more significant in these homoleptic Mo⁰ tris(diisocyanide) complexes than in [Ru(2,2′-bipyridine)₃]²⁺. Full article

(This article belongs to the Special Issue Photochemistry & Photophysics of Transition Metal Complexes)

► Show Figures

Figure 1

17 pages, 4216 KiB

Open AccessArticle

Heteroleptic [Cu(P^P)(N^N)][PF₆] Compounds with Isomeric Dibromo-1,10-Phenanthroline Ligands

Isaak Nohara

Aramis Keller

Nikolai Tarassenko

Alessandro Prescimone

Edwin C. Constable

and

Catherine E. Housecroft

Inorganics 2020, 8(1), 4; https://doi.org/10.3390/inorganics8010004 - 10 Jan 2020

Cited by 8 | Viewed by 3345

Abstract

A series of [Cu(P^P)(N^N)][PF₆] compounds are reported in which N^N is 2,9-dibromo-1,10-phenanthroline (2,9-Br₂phen), 3,8-dibromo-1,10-phenanthroline (3,8-Br₂phen) or 4,7-dibromo-1,10-phenanthroline (4,7-Br₂phen) and P^P is bis(2-(diphenylphosphano)phenyl)ether (POP) or 4,5-bis(diphenylphosphano)-9,9-dimethylxanthene (xantphos). The compounds were characterized by solution multinuclear NMR spectroscopy, mass spectrometry and a single-crystal X-ray analysis. Each compound underwent a partially reversible or irreversible copper-centred oxidation, the highest potential being for 2,9-Br₂phen-containing compounds. In solution, the compounds are weak yellow or orange emitters, whereas powdered samples exhibit yellow emissions with photoluminescence quantum yields of up to 45% for [Cu(xantphos)(2,9-Br₂phen)][PF₆] with an excited state lifetime τ_1/2 = 9.9 μs. Values of λ_em^max for [Cu(POP)(2,9-Br₂phen)][PF₆] and [Cu(xantphos)(2,9-Br₂phen)][PF₆] are blue-shifted with respect to compounds with the 3,8-and 4,7-isomers, both in solution and in the solid state. Full article

(This article belongs to the Special Issue Photochemistry & Photophysics of Transition Metal Complexes)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Special Issue "Photochemistry & Photophysics of Transition Metal Complexes"

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (5 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI