Photo-redox reactivity of titanium-oxo clusters: mechanistic insight into a two-electron intramolecular process, and structural characterisation of mixed-valent Ti(iii)/Ti(iv) products

Chemical Science
Tobias KrämerSebastian D Pike

Abstract

Small titanium-oxo-alkoxide clusters, [TiO(OR)(O2PR'2)]4, synthesised by the stoichiometric reaction of Ti(OiPr)4, phosphinic acid and water, undergo a photo-redox transformation under long-wave UV light. The photo-reaction generates blue coloured, mixed-valence Ti(iii)/Ti(iv)-oxo clusters alongside acetone and isopropanol by-products. This reactivity indicates the ability for photoactivated charge separation to occur in even the smallest of Ti-oxo clusters. EPR and NMR spectroscopic studies support a photo-redox mechanism that occurs via an intramolecular, two-electron pathway, directly relating to current doubling effects observed at TiO2 photoanodes in the presence of alcohols. The rate of photo-reaction is solvent dependent, with donor solvents supporting the formation of low coordinate Ti(iii) sites. The nature of the electronic transition is identified by DFT and TDDFT calculations as an oxygen to titanium charge transfer and it is possible to finetune the UV absorption onset observed by changing the phosphinate ligand. A two-electron photo-reduced cluster, [Ti4O4(O2PPh2)6], forms spontaneously from the photo-reaction and its structure is identified by X-ray crystallography with supporting DFT calculations. These indicate...Continue Reading

References

Sep 14, 2004·Inorganic Chemistry·Jian-Zhong WuG Charles Dismukes
Jul 23, 2009·Journal of the American Chemical Society·Meenakshi Dan-HardiGérard Férey
Jan 11, 2011·Chemical Society Reviews·Laurence Rozes, Clément Sanchez
May 24, 2013·Journal of the American Chemical Society·Carolyn N ValdezJames M Mayer
Sep 21, 2013·Journal of the American Chemical Society·Alina M SchimpfDaniel R Gamelin
Mar 26, 2014·Chemical Reviews·Yu BaiPeng Wang
May 7, 2014·Nano Letters·Ning LiuPatrik Schmuki
May 14, 2014·Chemical Reviews·Philip CoppensElżbieta Trzop
Jul 25, 2014·Chemical Communications : Chem Comm·Peter D MatthewsDominic S Wright
Sep 23, 2014·Chemical Reviews·Jenny SchneiderDetlef W Bahnemann
Oct 23, 2014·Journal of the American Chemical Society·Christian F A NegreVictor S Batista
Jun 2, 2016·Journal of the American Chemical Society·Wei-Hui FangJian Zhang
Oct 26, 2016·Dalton Transactions : an International Journal of Inorganic Chemistry·Manuel LechnerCarsten Streb
Oct 6, 2016·The Journal of Physical Chemistry Letters·Alejandro J Garza, Gustavo E Scuseria
Oct 14, 2016·Nature Communications·Sebastian D PikeCharlotte K Williams
Dec 17, 2016·Dalton Transactions : an International Journal of Inorganic Chemistry·Schirin HanfDominic S Wright
Nov 28, 2017·Chemical Society Reviews·Wei-Hui FangJian Zhang
Apr 11, 2018·Angewandte Chemie·Laurence R DoyleStephen T Liddle

❮ Previous
Next ❯

Methods Mentioned

BETA
electron paramagnetic resonance
NMR
X-ray

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.