Library · Materials, chemistry & fabrication
What Photochemical Synthesis got wrong, from 13 theses
Summary written by a model from the records below: Photochemical synthesis methods across the records frequently encountered difficulties with substrate degradation, poor selectivity, and competing off-pathway reactions. In several cases, researchers observed lower yields or inferior reaction control compared to established thermal, chemical, or alternative catalytic systems. These records come from graduate theses, 2021 to 2026, each labeled with its degree where the repository states it, and each links to its thesis. They were extracted by language models reading the full text, so treat each as a lead to read, not a verdict.
Plus 9 problems the authors left open, listed at the end.
Failure modes, by theses reporting them
Select a mode to jump to its records.
Light irradiation causes uncontrolled substrate decomposition and structural degradation
Photolytic reactions experienced severe degradation and uncontrolled decomposition across multiple species rather than yielding the desired products. Substrates and materials also suffered from destructive side pathways including oxygenation, complete photoluminescence quenching, and general loss of efficiency under irradiation.
Tried and failed
photochemical disulfide cleavage with hydridophosphorane applied to thiophosphorane synthesis. Outcome: unstable. Reason: uncontrolled reaction leading to decomposition across multiple species
Expanding Deoxygenative Transformations of Alcohols by Phosphorus Compounds Through Geometric Deformation · MIT · PhD
Tried and failed
photochemical dediazotisation via light irradiation applied to alkyl diazoolefins to generate vinylidenes. Outcome: unstable. Reason: irradiation caused decomposition and oxygenation rather than vinylidene generation
Isolation, Characterisation and Reactivity of N-Heterocyclic Diazoolefins · EPFL · PhD
Considered and rejected
Considered and rejected: Photochemical benzannulation conditions using UV irradiation for cyclic diazo enones abandoned due to low efficiency/decomposition; replaced by a thermal slow-addition protocol.
TANDEM BENZANNULATION-CYCLIZATION STRATEGIES FOR THE SYNTHESIS OF HIGHLY SUBSTITUTED INDOLES · MIT · PhD
Tried and failed
photochemical thiol-ene crosslinking applied to colloidal halide perovskite nanoplatelets. Outcome: unstable. Reason: light irradiation with dithiols caused severe structural degradation and complete photoluminescence quenching
Continuous Production and Improved Stabilities of Luminescent Colloidal Perovskite Nanocrystals as Next-Generation Emitters · Georgia Tech · PhD
Photochemical transformations produce lower yields and selectivity than alternative chemical or catalytic baselines
Direct or catalyst-free photochemical methods delivered inferior product yields, efficiency, and selectivity when compared against metal-catalyzed reactions or classical coupling protocols. Similarly, alternative photolysis precursors and routes generated lower photochemical efficiency and target product yields than established reference systems.
Lost to a baseline
Catalyst-free photochemical oxidative cyclization under direct blue light or 365 nm irradiation showed lower selectivity and product yields (40-49%) compared to the Ru(bpy)3Cl2-catalyzed reaction (72-83%)
Automated Execution and Optimization of Flow Chemistry on a Robotic Platform with Integrated Analytics · MIT · PhD
Lost to a baseline
Aitken's uracil photochemical route proceeded with higher photochemical efficiency than the 2-pyridone route
Photochemical approaches to azetidines · Nottingham · Doctorate
Lost to a baseline
Photochemical macrocyclization of Peptide-3 to Atosiban-3 gave a 12% overall yield, whereas classical two-electron PyAOP lactamization coupling gave an 18% overall yield.
PHOTOCHEMICAL MODIFICATION OF PEPTIDES ON RESIN VIA CHARGE-TRANSFER COMPLEXES · Penn · PhD
Tried and failed
photochemical oxidation using alternative radical precursor applied to aromatic compound oxidation product formation. Outcome: no signal. Reason: nitryl chloride photolysis produced substantially lower target quinone yields than molecular chlorine systems
Fate and oxidative impact of chlorine in indoor and outdoor air · UT Austin · PhD
Photochemical polymerizations suffer from poor reaction controllability and operational constraints compared to thermal methods
Light-initiated polymerizations failed to maintain temporal control when active catalytic species persisted and continued propagation in the dark. Consequently, researchers rejected photochemical polymerizations in favor of thermal protocols that offered superior reaction controllability and avoided UV light requirements on complex substrates.
Tried and failed
photochemical on-off temporal control of polymerization applied to bulk ring-opening metathesis polymerization. Reason: once photoactivated, active catalyst species persisted and propagation continued in the dark
Spatially defined crystallinity within multimaterial polymeric networks · UT Austin · PhD
Considered and rejected
Considered and rejected: Photochemically initiated polythiol-silica synthesis was rejected for thermal synthesis due to poorer reaction controllability despite faster kinetics.
Considered and rejected
Considered and rejected: Rejected photochemical free radical polymerization in favor of thermal initiator FRP because thermal FRP does not require UV light treatment and allows polymers to be dissolved and coated onto diverse 3D substrates.
Characterisation of the modulation of immune response to polymer implants using established and novel methods · Nottingham · PhD
Unreactive starting materials and photogenerated intermediates divert reactions into unproductive pathways
Starting materials or photogenerated species sometimes proved completely unreactive under light exposure, failing to undergo intended decarbonylation or cycloaddition steps. Unreactive intermediates and residual catalysts subsequently engaged in off-pathway processes, including hydrolysis upon moisture exposure or competitive oxidation during sequential steps.
Tried and failed
telescoped multi-step continuous-flow photochemical synthesis applied to sequential catalytic photochemical reactions. Reason: residual catalyst from the first step underwent competitive oxidation during the subsequent photochemical step
Automated Execution and Optimization of Flow Chemistry on a Robotic Platform with Integrated Analytics · MIT · PhD
Tried and failed
decarbonylation via thermal, photochemical, and chemical methods applied to phosphine-supported transition metal carbonyl complexes. Reason: Thermal and photolytic methods were unreactive, while chemical oxidants oxidized the supporting phosphine ligands instead
Expanding the coordination chemistry of bismuth : synthesis and characterization of heavy pnictogen ligated 3d transition metal complexes · UT Austin · PhD
Tried and failed
Photochemical ketene generation and enol ether cycloaddition applied to intermolecular cycloaddition with cyclic enol ethers. Reason: Ketene intermediate failed to undergo cycloaddition and hydrolysed upon exposure to water
Dual-biomimetic meroterpenoid syntheses. A study of acetylenic terpenes in polyene cyclizations applied to the synthesis of resorcylate natural products · Imperial · PhD
Left open by the authors
Problems the authors named and did not get to.
Left open
Investigate why TPO-induced photoreduction of c-Gel is irreversible compared to benzophenone/EDMAB photochemistry. Blocker: Requires wet-lab synthetic chemistry and photochemical characterization equipment.
Control of Network Topology in Photopolymer Networks for Additive Manufacturing · MIT · PhD
Left open
Design and synthesize alkyne-substituted diazo sulfonium ester motifs compatible with CuAAC click chemistry that retain photoreactivity. Blocker: Requires synthetic organic chemistry wet-lab synthesis and photochemical experimental validation
Towards the development of a visible light-enabled histidine-selective protein modification strategy using diazo sulfonium-based probes · Cambridge · PhD
Left open
Optimize reaction conditions to produce benzoic acid or acetophenone in higher yields and at larger scales via iron halide photooxidation. Blocker: Requires a wet chemistry laboratory, photochemical reactors, and physical chemical reagents.
POLYMER DECONSTRUCTION AND CHEMICAL TRANSFORMATION THROUGH CATALYST-CONTROLLED PHOTOOXIDATION AND PHOTOTHERMAL CONVERSION · Cornell · PhD
Left open
Investigate intrinsic photochemical stability of benzothiadiazole units across a wider range of conjugated organic molecules using spectroscopy and computational chemistry. Blocker: Requires wet lab preparation, photo-degradation apparatus, and spectroscopic characterization of conjugated molecules.
Non-fullerene acceptor based organic photovoltaics: understanding photostability and low-light performance · Imperial · PhD
Left open
Determine whether OH oxidation or photolysis governs brown carbon photochemical bleaching across diverse biomass fuel types. Blocker: Requires controlled laboratory photochemical chamber experiments or specialized empirical kinetic data for various fuel types
Investigating the representation of smoke and its implications for air quality and climate · MIT · PhD
Left open
Perform photolytic lactonization of Co(III)–benzoates using visible light to generate aryl carboxylic acid radicals for C–heteroatom bond formation. Blocker: Requires wet lab synthetic chemistry facilities, reagents, and photochemical equipment
Redox non-innocent bis(phenoxide) pincer ligand cobalt complexes for selective radical C–H (trifluoro)alkylation through photoinduced cobalt–R(f) bond weakening · Georgia Tech · PhD
Left open
Synthesize and test structural variations of cyclic xanthate monomer 45 for light-triggered homopolymerization behavior. Blocker: Requires wet lab facilities for chemical synthesis, photochemical initiation, and polymer characterization.
Thiocarbonyl Platform for Degradable Radical Polymers · Georgia Tech · PhD
Left open
Determine the molecular mechanism of light-induced gelation and covalent crosslinking in FUS biomolecular condensates. Blocker: Requires experimental wet-lab biochemistry and biophysical assays to observe photochemical bond formation in protein condensates.
Mechanics of Interpenetrating Biopolymer Networks in the Cytoskeleton and Biomolecular Condensates · Harvard · PhD
Left open
Measure the photodegradation rates of activated ribonucleotides and 5′-5′-imidazolium-bridged dinucleotides under UV radiation. Blocker: Requires wet-lab experimental setup and UV irradiation apparatus to measure photochemical degradation kinetics.
Who has worked on this
Authors of the public theses cited on this page, most-cited first.
- Anirudh Manoj Kumar Nambiar · MIT · PhD · 2022
Automated Execution and Optimization of Flow Chemistry on a Robotic Platform with Integrated Analytics - Marc Jens Friedrich Wolter · Tübingen · PhD · 2026
Design, Preparation and Characterization of Stationary Phases for High Performance Liquid Chromatography and their Application in Pharmaceutical and Bioanalytical Analysis - Sewon Oh · Cornell · PhD · 2025
POLYMER DECONSTRUCTION AND CHEMICAL TRANSFORMATION THROUGH CATALYST-CONTROLLED PHOTOOXIDATION AND PHOTOTHERMAL CONVERSION - Chris S. Kuehner · Georgia Tech · PhD · 2023
Redox non-innocent bis(phenoxide) pincer ligand cobalt complexes for selective radical C–H (trifluoro)alkylation through photoinduced cobalt–R(f) bond weakening - Nathan H. Faialaga · MIT · PhD · 2023
TANDEM BENZANNULATION-CYCLIZATION STRATEGIES FOR THE SYNTHESIS OF HIGHLY SUBSTITUTED INDOLES - Mahmoud Elkhalifa · Penn · PhD · 2023
PHOTOCHEMICAL MODIFICATION OF PEPTIDES ON RESIN VIA CHARGE-TRANSFER COMPLEXES - Waraporn Suvannapruk · Nottingham · PhD · 2023
Characterisation of the modulation of immune response to polymer implants using established and novel methods - Stephanie Jingsi Zhang · Harvard · PhD · 2022
Towards Building a Self-replicating Protocell: Nonenzymatic RNA Copying Driven by Potentially Prebiotic Activation and Higher-order Behaviors in Prebiotic Vesicles - Thérèse (Tess) Carter · MIT · PhD · 2022
Investigating the representation of smoke and its implications for air quality and climate - Ronald Aubrey Smith · Georgia Tech · PhD · 2022
Thiocarbonyl Platform for Degradable Radical Polymers - Gill Biesold · Georgia Tech · PhD · 2022
Continuous Production and Improved Stabilities of Luminescent Colloidal Perovskite Nanocrystals as Next-Generation Emitters - Yinan Shen · Harvard · PhD · 2022
Mechanics of Interpenetrating Biopolymer Networks in the Cytoskeleton and Biomolecular Condensates
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