About

Thomas Gianetti is an Associate Professor at the University of Arizona in the Department of Chemistry and Biochemistry. He earned his B.S. and M.Sc. degrees in 2009 from CPE Lyon in France, followed by a Ph.D. in 2014 from the University of California, Berkeley. He completed postdoctoral research from 2014 to 2017 at ETH Zürich in Switzerland. Gianetti's research focuses on the development of new chemical structure platforms that have enabled advances in chemical catalysis for photoinduced chemistry, ligand frameworks for organometallic chemistry, and next-generation solution phase electrode materials for batteries. His work involves the synthesis and application of fused heterocyclic stable carbocations, which can serve as Lewis acids, ligands, photocatalysts, or electrolytes for energy storage. His group provides rigorous training in organic and inorganic synthesis, air-sensitive organometallic synthesis, solid-state synthetic methods, and various physical methods including X-ray diffraction, electron microscopy, NMR, UV/vis, IR, EPR, and cyclic voltammetry.

Research topics

• Organic chemistry
• Chemistry
• Photochemistry
• Inorganic chemistry
• Chemical physics
• Electrical engineering
• Atomic physics
• Combinatorial chemistry
• Chemical engineering
• Thermodynamics
• Physical chemistry

Selected publications

• Exploring the Synthesis and Properties of Fluorinated Cationic Triangulenes and Their Precursors

  Chemistry - A European Journal · 2025-01-29

  articleOpen accessSenior authorCorresponding

  Abstract Fluorination of tris(2,6‐dimethoxyphenyl)‐methylium ((DMP) 3 C + ) was achieved through the partial defluorination of the methyl 2,3,5,6‐tetrafluorobenzoate via nucleophilic aromatic substitution. Using the fluorinated 2F ((DMP) 3 C + ) as a precursor, fluorinated tetramethoxy‐ and dimethoxyquin‐ acridinium salts ( 2F 4 and 2F 5 respectively) and trioxo‐, azadioxo‐, and diazaoxo‐ triangulenium salts ( 2F 6 , 2F 7 and 2F 8 respectively) were synthesized successfully in good to moderate yields. Fluorination induced significant red shifts in absorption (16 to 29 nm) and emission (13 to 41 nm) maxima, and increased electrophilicity as evidenced by lower reduction potentials. X‐ray structural analysis showed distinct packing patterns compared to the non‐fluorinated analogues, indicating the presence of molecular dipoles.

  PublisherOA PDFDOI

• Isolated Neutral Organic Radical Unveiled Solvent‐Radical Interaction in Highly Reducing Photocatalysis

  Angewandte Chemie International Edition · 2025-01-03 · 12 citations

  articleSenior authorCorresponding

  Abstract Diffusion‐limited kinetics is a key mechanistic debate when consecutive photoelectron transfer (conPET) is discussed in photoredox catalysis. In situ generated organic photoactive radicals can access catalytic systems as reducing as alkaline metals that can activate remarkably stable bonds. However, in many cases, the extremely short‐lived transient nature of these doublet state open‐shell species has led to debatable mechanistic studies, hindering adoption and development. Herein, we document the use of an isolated and stable neutral organic n PrDMQA radical as a highly photoreducing species. The isolated radical offers a unique platform to investigate the mechanism behind the photocatalytic activity of organic photocatalyst radicals. The involvement of reduced solvent is observed, formed by single electron transfer (SET) between the short‐lived excited state n PrDMQA radical and the solvent. In our detailed mechanistic studies, spectroscopic and chemical affirmation of solvent reduction is strongly evident. Reduction of aryl halides, including difluoroarenes is presented as a model study of the conPET method. Further, the activation of N 2 O, a greenhouse gas that is yet to be activated by photoredox catalysis, is showcased in the absence of a transition metal.

  PublisherDOI

• Isolated Neutral Organic Radical Unveiled Solvent‐Radical Interaction in Highly Reducing Photocatalysis

  Angewandte Chemie · 2025-01-03 · 1 citations

  articleSenior authorCorresponding

  Abstract Diffusion‐limited kinetics is a key mechanistic debate when consecutive photoelectron transfer (conPET) is discussed in photoredox catalysis. In situ generated organic photoactive radicals can access catalytic systems as reducing as alkaline metals that can activate remarkably stable bonds. However, in many cases, the extremely short‐lived transient nature of these doublet state open‐shell species has led to debatable mechanistic studies, hindering adoption and development. Herein, we document the use of an isolated and stable neutral organic n PrDMQA radical as a highly photoreducing species. The isolated radical offers a unique platform to investigate the mechanism behind the photocatalytic activity of organic photocatalyst radicals. The involvement of reduced solvent is observed, formed by single electron transfer (SET) between the short‐lived excited state n PrDMQA radical and the solvent. In our detailed mechanistic studies, spectroscopic and chemical affirmation of solvent reduction is strongly evident. Reduction of aryl halides, including difluoroarenes is presented as a model study of the conPET method. Further, the activation of N 2 O, a greenhouse gas that is yet to be activated by photoredox catalysis, is showcased in the absence of a transition metal.

  PublisherDOI

• Low-Energy Photocatalytic C–H Amination of Arenes Enabled by an Orange-Light Organic Photooxidant

  ChemRxiv · 2025-12-03

  articleSenior author

  Direct C-H amination of arenes provides rapid access to C-N bonds in pharmaceuticals, agrochemicals, and functional materials, yet most photoredox approaches require high-energy blue light. Here, we introduce a low-energy orange-light photoredox platform for aryl C-H amination using a fluorinated azadioxotriangulenium (2FADOTA⁺) photocatalyst. This system enables efficient C-H amination of electron-rich arenes, heteroarenes, and sterically demanding scaffolds with both azole and aliphatic amines, including amino acid esters. Late-stage functionalization of medicinally relevant molecules is achieved under mild conditions, demonstrating broad applicability. Mechanistic studies support arene oxidation as the productive pathway. This work demonstrates how low-energy photooxidants can unlock sustainable strategies for challenging synthetic transformations.

  PublisherDOI

• Orange-Light-Driven Skeletal Editing: Low-Energy Photoredox Furan-to-Pyrrole Conversion

  ChemRxiv · 2025-11-02

  articleSenior author

  Long-wavelength photoredox catalysis promises safer, energy-efficient transformations but remains constrained by limited redox windows. We introduce a new class of fluorinated azadioxotriangulenium (2FADOTA⁺) photocatalysts that overcome these limitations, acting as potent photooxidants (E*red = +1.76–1.89 V vs SCE) under orange-light irradiation (595 nm). These carbocation-based catalysts promote the direct furan-to-pyrrole conversion via oxygen–nitrogen atom exchange, a skeletal editing process previously requiring blue light. The transformation proceeds efficiently across diverse furans and nitrogen nucleophiles, including amino acid esters and pharmaceutical derivatives, and is scalable to gram quantities. Mechanistic studies, supported by Stern–Volmer analysis, confirm oxidative quenching of the excited photocatalyst by the furan substrate. This work provides a tunable platform for low-energy photoredox catalysis and establishes fluorination as a general design principle for expanding the redox reach of long-wavelength organic photocatalysts.

  PublisherDOI

• Selective dehydrogenation of ammonia borane to borazine and derivatives by rhodium olefin complexes

  Dalton Transactions · 2024-01-01 · 4 citations

  articleOpen accessCorresponding

  This report presents a selective synthetic approach towards borazine from ammonia borane using a dinuclear rhodium olefin homogeneous catalyst. The synthesis and spectroscopic characterization of a dirhodium ammonia borane complex as an intermediate provides insight into a possible mode of activation.

  PublisherOA PDFDOI

• Ultrafast Dynamics of a Red-Light-Activated Organic Photocatalyst in the Oxidative Hydroxylation of Phenylboronic Acid

  ChemRxiv · 2024-05-17 · 1 citations

  preprintOpen access

  Over the past few years, photoredox catalysis has led to significant transformations in modern synthetic chemistry. It has allowed the development of new synthetic pathways for the assembly of complex molecular scaffolds using light as a driving force. However, investigations of the ultrafast light-initiated mechanisms required for these reactions are relatively scarce. Here we follow the ultrafast dynamics of a red-light organic photocatalyst, N,N′-di-n-propyl-1,13-dimethoxyquinacridinium (nPr-DMQA+), in the aerobic oxidative hydroxylation of phenylboronic acid using transient absorption and time correlated single photon counting spectroscopy. Global target analysis supports a reaction mechanism that proceeds through the excited triplet state of nPr-DMQA+, leading to the generation of a superoxide anion and subsequent oxidative hydroxylation. The triplet pathway proposed here has relatively wide application in organic photocatalytic oxidative reactions including those using methylene blue and other organic dyes as catalysts. Observation of the ultrafast dynamics of nPr-DMQA+ as it acts as a catalyst can provide insights to improve the efficiency of oxidative hydroxylation reactions and the mechanisms of photoredox catalysis more broadly.

  PublisherOA PDFDOI

• Designing the next generation of symmetrical organic redox flow batteries using helical carbocations

  Energy Materials · 2024-03-20 · 6 citations

  articleOpen accessSenior authorCorresponding

  In recent years, non-aqueous fully organic Redox Flow Batteries (RFBs) have displayed potential in broadening the electrochemical window and enhancing energy density in RFBs by relying on redox-active organic molecules to provide improved sustainability in comparison to metal-based charge carriers. Of particular interest, systems that rely on a single bipolar redox molecule (BRM) for their operation, known as symmetrical organic RFBs, have gained momentum as the utilization of a BRM eliminates membrane crossover issues, thus extending the lifespan of electrical energy storage systems while reducing their cost. In this manuscript, we will present our contribution to this field through the design of tunable bipolar molecules within the helicene carbocation class. This particular type of BRM is synthetically very affordable and has proven to be highly modifiable and robust. Through the examination of 11 examples, we will demonstrate how an approach based on readily available electrochemical tools can be efficiently employed to generate and assess a library of compounds for future full flow RFB applications.

  PublisherOA PDFDOI

• Modern organophotocatalysts: a new inspiration source for Symmetrical Organic Redox Flow Batteries

  ChemRxiv · 2024-11-07

  preprintOpen accessSenior author

  Redox flow batteries (RFBs) have emerged as significant energy storage systems amid the growing adoption of renewable energy. However, the advancement of all-organic RFBs is hindered by material crossover, limited energy density, and the time-consuming selection of suitable electrolyte partners. To address these challenges, bipolar redox-active organic molecules (BRMs) show promise for charge storage in symmetric organic redox flow batteries (SORFBs), although their development can be complex and tedious. In this study, we report an approach aimed at streamlining the identification of suitable compounds through an examination of the organophotocatalyst literature, illustrated through six acridinium compounds exhibiting stable redox states. These compounds were thoroughly characterized in electrochemical cells and subjected to cycling tests in fully symmetric flow batteries. Notably, a trisubstituted electron-rich acridinium compound emerged as a potential candidate, demonstrating over 20 days of cycling stability. Given the extensive library of organic catalysts and the advantages of SORFB designs, this approach will prove to be essential for developing an innovative electrochemical storage system.

  PublisherOA PDFDOI

• Red Light–Blue Light Chromoselective C(sp²)–X Bond Activation by Organic Helicenium-Based Photocatalysis

  Journal of the American Chemical Society · 2024-03-18 · 50 citations

  articleSenior authorCorresponding

  Chromoselective bond activation has been achieved in organic helicenium (nPr-DMQA+)-based photoredox catalysis. Consequently, control over chromoselective C(sp2)–X bond activation in multihalogenated aromatics has been demonstrated. nPr-DMQA+ can only initiate the halogen atom transfer (XAT) pathway under red light irradiation to activate low-energy-accessible C(sp2)–I bonds. In contrast, blue light irradiation initiates consecutive photoinduced electron transfer (conPET) to activate more challenging C(sp2)–Br bonds. Comparative reaction outcomes have been demonstrated in the α-arylation of cyclic ketones with red and blue lights. Furthermore, red-light-mediated selective C(sp2)–I bonds have been activated in iodobromoarenes to keep the bromo functional handle untouched. Finally, the strength of the chromoselective catalysis has been highlighted with two-fold functionalization using both photo-to-transition metal and photo-to-photocatalyzed transformations.

  PublisherDOI

Frequent coauthors

• Yingxu Wei

  100 shared

• Hao Wu

  Northeast Electric Power University

  100 shared

• Inbal L. Zak

  Ben-Gurion University of the Negev

  100 shared

• Radhika Peddinti

  100 shared

• Mu‐Chun Wang

  Min Sheng General Hospital

  100 shared

• Peng‐Zi Wang

  Central China Normal University

  100 shared

• Wei Hong

  Southeast University

  100 shared

• B.-Q He

  Ben-Gurion University of the Negev

  100 shared

Education

• Ph.D., Chemistry

  University of California Berkeley

  2014

• B.S. and M.Sc., Chemistry and Chemical Engineering

  Ecole Supérieure Chimie Physique Electronique de Lyon

  2009