Coastal aquatic pollutants degradation using ZnCo2O4 nanorods.

Water pollution has caused problems in coastal areas, rivers, lakes, and other important water sources around the world as a result of inappropriate waste management. Meanwhile, these pollutants are harmful to humans and aquatic life. Textile dye effluent methyl orange (MO) was used in this work for dye degradation studies employing nanocomposites. As a result, the importance of synthesizing pure ZnO and Co3O4 nanoparticles with composites of ZnCo2O4 (zinc cobaltite) nanorods in three various proportions (90:10, 75:25, and 50:50) is emphasized in this study. Many advanced approaches were used to assess the various features of these materials, including size and shape. Fourier transform infrared (FT-IR) spectroscopy was used to determine the vibrational modes of the materials. The absorption measurements were then carried out using UV-vis spectroscopic techniques, and the photocatalytic breakdown of MO was done under visible light irradiation. The findings revealed that pure materials were inadequate for visible light activity, resulting in decreased degradation efficiencies. Spinel cobaltite structures have potential degradation efficiency under visible light, while ZnCo2O4 (50:50) catalyst has superior degradation efficiency of 59.8% over MO. The crystallite size, morphology, functional group, absorption wavelength, and band gap all play important roles in enhancing the material's photocatalytic activity under visible light. Meanwhile, ZnCo2O4 spinel structures are crucial for increasing charge carriers and reducing electron-hole recombination. As a result, zinc cobaltite minerals are widely used in industrial dye degradation applications.

Visible light irradiation enhanced sulfidated zero-valent iron/peroxymonosulfate process for organic pollutant degradation.

This study developed a novel process named sulfidated zero-valent iron/peroxymonosulfate/visible light irradiation (S-mZVI/PMS/vis) for enhanced organic pollutant degradation. The S-mZVI/PMS/vis process exhibited remarkable catalytic activity, achieving a 99.6% rhodamine B (RhB) removal within 10 min. The degradation rate constant of RhB by the S-mZVI/PMS/vis process was found to be 6.49 and 79.84 times higher than that by the S-mZVI/PMS and PMS/vis processes, respectively. Furthermore, the S-mZVI/PMS/vis process worked efficiently across a wide pH range (3.0-9.0), and the result of five-cycle experiments demonstrated the excellent reusability and stability of S-mZVI. Radical quenching tests and electron paramagnetic resonance analysis indicated that ·O2-, 1O2, and h+ significantly contributed to the degradation of RhB through the S-mZVI/PMS/vis process. The visible light irradiation increased the Fe2+ concentration, improved the Fe3+/Fe2+ cycle, and consequently enhanced the PMS decomposition, reactive species production, and RhB degradation. This work offers a promising strategy to highly efficiently activate PMS for organic pollutants elimination from aqueous solutions.

Photodegrading rhodamine B dye with cobalt ferrite-graphitic carbon nitride (CoFe2O4/g-C3N4) composite.

The present research utilizes a sol-gel approach to create a CoFe2O4/g-C3N4 nanocomposite (NC) and explored several analytical methods to evaluate physical, chemical and optical based characteristics via XRD, FTIR, UV-vis, SEM/EDS and XPS for the prepared pure CoFe2O4, g-C3N4, and CoFe2O4/g-C3N4 NC. The XRD results show that the prepared g-C3N4, CoFe2O4, exhibits hexagonal and cubic phases respectively, whereas the g-C3N4/CoFe2O4 NC exhibit mixing of two phases. The energy band gaps for pure g-C3N4, CoFe2O4 and g-C3N4/CoFe2O4 NC values are viz., 2.75, 1.3, and 2.4 eV. As photocatalysts, synthesized materials were utilized for the decomposition of Rhodamine-B (RhB) dye. Finally, the CoFe2O4/g-C3N4 NC showed good performance of photocatalysis for RhB dye disintegration under the stimulus of visible light. According to the induced visible light, the rate at which the photocatalytic degradation occurs for the CoFe2O4/g-C3N4 NC was found to be 57% in 120 min and this is greater when compared with pure catalysts like CoFe2O4 (28%) and g-C3N4 (10%). These outcomes suggest that the prepared NC have efficiently worked during the photocatalytic process compared with its pure materials.

Construction of a g-C3N4/Bi(OH)3 Heterojunction for the Enhancement of Visible Light Photocatalytic Antibacterial Activity.

Photocatalytic technology has been recently conducted to remove microbial contamination due to its unique features of nontoxic by-products, low cost, negligible microbial resistance and broad-spectrum elimination capacity. Herein, a novel two dimensional (2D) g-C3N4/Bi(OH)3 (CNB) heterojunction was fabricated byincorporating Bi(OH)3 (BOH) nanoparticles with g-C3N4 (CN) nanosheets. This CNB heterojunction exhibited high photocatalytic antibacterial efficiency (99.3%) against Escherichia coli (E. coli) under visible light irradiation, which was 4.3 and 3.4 times that of BOH (23.0%) and CN (28.0%), respectively. The increase in specific surface area, ultra-thin layered structure, construction of a heterojunction and enhancement of visible light absorption were conducive to facilitating the separation and transfer of photoinduced charge carriers. Live/dead cell staining, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) assays and scanning electron microscopy (SEM) have been implemented to investigate the damage to the cell membrane and the leakage of the intracellular protein in the photocatalytic antibacterial process. The e-, h+ and O2•- were the active species involved in this process. This study proposed an appropriate photocatalyst for efficient treatment of bacterial contamination.

Thioxanthone-Based Siloxane Photosensitizer for Cationic/Radical Photopolymerization and Photoinduced Sol-Gel Reactions.

In this investigation, a multifunctional visible-light TX-based photosensitizer containing a siloxane moiety (TXS) was designed with a good overall yield of 54%. The addition of a siloxane moiety enabled the incorporation of a TX photosensitizer into a siloxane network by photoinduced sol-gel chemistry, thus avoiding its release. Both liquid 1H and solid-state 29Si NMR measurements undeniably confirmed the formation of photoacids resulting from the photolysis of the TXS/electron acceptor molecule (Iodonium salt), which promoted the photoinduced hydrolysis/condensation of the trimethoxysilane groups of TXS, with a high degree of condensation of its inorganic network. Notably, the laser flash photolysis, fluorescence, and electron paramagnetic resonance spin-trapping (EPR ST) experiments demonstrated that TXS could react with Iod through an electron transfer reaction through its excited states, leading to the formation of radical initiating species. Interestingly, the TXS/Iod was demonstrated to be an efficient photoinitiating system for free-radical (FRP) and cationic (CP) polymerization under LEDs@385, 405, and 455 nm. In particular, whatever the epoxy monomer mixtures used, remarkable final epoxy conversions were achieved up to 100% under air. In this latter case, we demonstrated that both the photoinduced sol-gel process (hydrolysis of trimethoxysilane groups) and the cationic photopolymerization occurred simultaneously.

Visible-Light-Irradiated Multicomponent Reactions of Aliphatic Amines, Propiolate Acid Esters, and CF3 SO2 Na for Accessing ß-CF3 Enamines.

A novel one-pot two-step multicomponent reaction has been achieved for the preparation of ß-CF3 enamines by using different aliphatic amines, propiolates, and CF3 SO2 Na as starting material. In this protocol, various aliphatic amines including primary amines, cyclic or acyclic secondary amines were demonstrated to be good coupling partners, and different ß-CF3 enamines were obtained in moderate to good yields. Among them, the primary aliphatic amines only gave pure (E)-ß-CF3 enamines as products. The synthetic utility of the MCRs strategy was further demonstrated by mild conditions, gram-scale synthesis and natural sunlight-induced protocol. Preliminary mechanistic studies suggest that this trifluoromethylation of C(sp2 )-H involves radical process.

Photocatalytic Hydrogen Production Activity and Mechanism of New Nickel-Based Sulfur Complexes in Aqueous Solution.

The development of industry and the increase in population have caused energy shortages and environmental pollution problems. Developing clean and storable new energy is identified as a key way to solve the problems above. Hydrogen is viewed as the most potential energy carrier due to its high calorific value and pollution-free. To convert solar energy into hydrogen energy, three nickel-based catalysts, Ni(aps)(pys)2 (aps=2-amino-2-phenylacetic salicylaldehyde) (1), Ni(ads)(pys)2 (ads=aniline salicylaldehyde, pys=pyridine-2-thiolate) (2), Ni(acs)(pys)2 (acs=aniline 5-chlorosalicylaldehyde) (3), were synthesized and explored as photocatalysts for hydrogen production. A three-component photocatalytic system for hydrogen production was constructed using target complex as photocatalyst, triethanolamine (TEOA) as electron sacrificial agent and fluorescein (FL) as photosensitizer. Under the optimum conditions, about 1504 µmol of H2 can be obtained with 25 mg catalyst 2 after 3 hours of irradiation. Finally, the hydrogen-production mechanism was discussed by experimental and theoretical methods.

Synthesis of TiO2, TiO2/PAni, TiO2/PAni/GO nanocomposites and photodegradation of anionic dyes Rose Bengal and thymol blue in visible light.

Nowadays, fast-growing industrialization has resulted in the release of enormous amounts of contaminants such as toxic dyes into water bodies and leading to cause health and environmental risks. In this regard, we prepared inorganic nanocomposites for the treatment of toxic dyes. Hence, we synthesized TiO2/PAni/GO nanocomposites and examined them by using XRD, SEM, TEM, UV-Vis spectroscopy, BET analysis, and a photoluminescence investigation. In addition, band gap energies of the nanocomposites were determined, and Total Organic Carbon (TOC) testing was used to determine dye degradation levels. The photocatalytic degradations of Thymol Blue and Rose Bengal dyes were investigated at different dye concentrations, illumination periods, solution pH values, and photocatalyst dosages. By using TiO2/PAni/GO, TiO2/PAni, and TiO2 at neutral pH, a photocatalyst dose of 1600 mg/L, and exposure to visible light, Thymol Blue and Rose Bengal were photodegraded 85-99%, 60-97%, and 10-20%, respectively, at a concentration of 25 ppm (180 min). Reductions in the TOCs confirmed their photodegradation, and a kinetic study revealed photodegradation followed first-order kinetics. This study shows the coating of polyaniline (PAni) and graphene oxide (GO) on TiO2 improved its ability to photodegrade Thymol Blue and Rose Bengal dye.

Novel visible-light-active P-g-CN-based α-Bi2O3/WO3 ternary photocatalysts with a dual Z-scheme heterostructure for the efficient decomposition of refractory ultraviolet filters and environmental hormones: Benzophenones.

The ubiquitous and refractory benzophenone (BP)-type ultraviolet filters, which are also endocrine disruptors, were commonly detected in the aquatic matrix and could not be efficiently removed by conventional wastewater treatment processes, thus causing extensive concern. Herein, a novel ternary nanocomposite, P-g-CN/α-Bi2O3/WO3 (P-gBW), was successfully fabricated by mixing cocalcinated components and applied to the decomposition of BP-type ultraviolet filters. The dual-Z-scheme heterostructure of P-gBW enhances visible-light absorption, efficiently facilitates separation and mobility, and prolongs the lifetime of photoinduced charge carriers via double charge transfer mechanisms. The optimum 95 wt% P-gBW exhibited excellent photocatalytic activity, degrading 96% 4-hydroxy benzophenone (4HBP) within 150 min and 93% 2,2',4,4'-tetrahydroxybenzophenone (BP-2) within 100 min under visible-light illumination, respectively. The pseudo-first-order rate constant of 4HBP (1.15 h-1) was 6.8-, 3.1-, 3.3- and 2.2-fold higher than those of WO3, P-g-CN, α-Bi2O3, and P-g-CN/α-Bi2O3, respectively, while that of BP-2 (1.71 h-1) was 5.2-, 2.2-, 3.2- and 1.5-fold higher, respectively. The improved photocatalytic degradation was attributed to efficient photoinduced charge carrier separation and migration and prevented the recombination of electron holes, as verified by photoluminescence, transient photocurrent response, and electrochemical impedance spectroscopy. Trapping experiments, electron paramagnetic resonance, and band energy position indicated an efficient dual-Z-scheme heterostructure.

Preparation and Property Characterization of Sm2EuSbO7/ZnBiSbO5 Heterojunction Photocatalyst for Photodegradation of Parathion Methyl under Visible Light Irradiation.

An unprecedented photocatalyst, Sm2EuSbO7, was successfully fabricated in this paper, through a high-temperature solid-state calcination method, which represented its first ever synthesis. Additionally, using the solvothermal method, the Sm2EuSbO7/ZnBiSbO5 heterojunction photocatalyst (SZHP) was fabricated, marking its debut in this study. XRD analysis confirmed that both Sm2EuSbO7 and ZnBiSbO5 exhibited pyrochlore-type crystal structures with a cubic lattice, belonging to the Fd3m space group. The crystal cell parameter was determined to be 10.5682 Å or 10.2943 Å for Sm2EuSbO7 or ZnBiSbO5, respectively. The band gap width measured for Sm2EuSbO7 or ZnBiSbO5 was 2.73 eV or 2.61 eV, respectively. Under visible light irradiation for 150 min (VLTI-150 min), SZHP exhibited remarkable photocatalytic activity, achieving 100% removal of parathion methyl (PM) concentration and 99.45% removal of total organic carbon (TOC) concentration. The kinetic constant (k) for PM degradation and visible light illumination treatment was determined to be 0.0206 min-1, with a similar constant k of 0.0202 min-1 observed for TOC degradation. Remarkably, SZHP exhibited superior PM removal rates compared with Sm2EuSbO7, ZnBiSbO5, or N-doped TiO2 photocatalyst, accompanied by removal rates 1.09 times, 1.20 times, or 2.38 times higher, respectively. Furthermore, the study investigated the oxidizing capability of free radicals through the use of trapping agents. The results showed that hydroxyl radicals had the strongest oxidative capability, followed by superoxide anions and holes. These findings provide a solid scientific foundation for future research and development of efficient heterojunction compound catalysts.

Effect of Copper-Modification of g-C3N4 on the Visible-Light-Driven Photocatalytic Oxidation of Nitrophenols.

Graphitic carbon nitride (g-C3N4) has proved to be a promising heterogeneous photocatalyst in the visible range. It can be used, among others, for the oxidative conversion of environmentally harmful nitrophenols occurring in wastewater. However, its photocatalytic activity needs to be enhanced, which can be achieved by modification with various dopants. In our work, copper-modified g-C3N4 was prepared by ultrasonic impregnation of the pristine g-C3N4 synthesized from thiourea. The morphology, microstructure, and optical properties of the photocatalysts were characterized by XRD, FT-IR, DRS, SEM, XPS, and TEM. DRS analysis indicated a slight change in both the CB and the VB energies of Cu/g-C3N4 compared to those of g-C3N4. The efficiency of the photocatalysts prepared was tested by the degradation of nitrophenols. Copper modification caused a sevenfold increase in the rate of 4-nitrophenol degradation in the presence of H2O2 at pH = 3. This dramatic enhancement can be attributed to the synergistic effect of copper and H2O2 in this photocatalytic system. A minor Fenton reaction role was also detected. The reusability of the Cu/g-C3N4 catalyst was demonstrated through five cycles. Copper-modified g-C3N4 with H2O2 proved to be applicable for efficient visible-light-driven photocatalytic oxidative degradation of nitrophenols.

Ti3 C2 TX MXene Modified with ZnTCPP with Bacteria Capturing Capability and Enhanced Visible Light Photocatalytic Antibacterial Activity.

Light-assisted antibacterial therapy is a promising alternative to antibiotic therapy due to the high antibacterial efficacy without bacterial resistance. Recent research has mainly focused on the use of near-infrared light irradiation to kill bacteria by taking advantage of the synergistic effects rendered by hyperthermia and radical oxygen species. However, photocatalytic antibacterial therapy excited by visible light is more convenient and practical, especially for wounds. Herein, a visible light responsive organic-inorganic hybrid of ZnTCPP/Ti3 C2 TX is designed and fabricated to treat bacterial infection with antibacterial efficiency of 99.86% and 99.92% within 10 min against Staphylococcus aureus and Escherichia coli, respectively. The porphyrin-metal complex, ZnTCPP, is assembled on the surface of Ti3 C2 TX MXene to capture bacteria electrostatically and the Schottky junction formed between Ti3 C2 TX and ZnTCPP promotes visible light utilization, accelerates charge separation, and enhances the mobility of photogenerated charges, and finally increases the photocatalytic activity. As a result of the excellent bacteria capturing ability and photocatalytic antibacterial effects, ZnTCPP/Ti3 C2 TX exposed to visible light has excellent antibacterial properties in vitro and in vivo. Therefore, organic-inorganic materials that have been demonstrated to possess good biocompatibility and enhance wound healing have large potential in bio-photocatalysis, antibacterial therapy, as well as antibiotics-free treatment of wounds.

Catalyst-free [2 + 2] photocycloadditions between benzils and olefins under visible light.

The catalyst-free [2 + 2] photocycloaddition between benzils and simple olefins is reported. The adoption of visible light proved essential for the transformation, as shorter wavelengths led to uncontrolled decomposition. When cyclic olefins were used, the reaction occurred smoothly to afford the expected oxetanes regio- and stereoselectively after 24 h of irradiation. In contrast, in the case of acyclic olefins, longer reaction times were typically required and small amounts (ca. 20%) of [4 + 2] photocycloadducts and by-products deriving from competitive hydrogen atom abstraction were observed. The selectivity of the transformation could be consistently improved by decreasing the reaction temperature, thus restoring the desired [2 + 2] reactivity. An overall mechanistic picture is also offered based on the chemical and photophysical quenching experiments and the stereochemical output is rationalized based on Griesbeck models.

Visible Light Accelerates Cr(III) Release and Oxidation in Cr-Fe Chromite Residues: An Overlooked Risk of Cr(VI) Reoccurrence.

The reduced chromite ore processing residue (rCOPR) deposited in environments is susceptible to surrounding factors and causes reoccurrence of Cr(VI). However, the impact of natural sunlight on the stability of rCOPR is still unexplored. Herein, we investigated the dissolution and transformation behaviors of Cr(III)-Fe(III) hydroxide, a typical Cr(III)-containing component in rCOPR, under visible light. At acidic conditions, the release rate of Cr(III) under illumination markedly increased, up to 7 times higher than that in the dark, yet no Cr(VI) was produced. While at basic conditions, only Cr(VI) was obtained by photo-oxidation, with an oxidation rate of ∼7 times higher than that by δ-MnO2 under dark conditions at pH 10, but no reactive oxygen species was generated. X-ray absorption near-edge structure and density functional theory analyses reveal that coexisting Fe in the solid plays a critical role in the pH-dependent release and transformation of Cr(III), where photogenerated Fe(II) accelerates Cr(III) produced at acidic conditions. Meanwhile, at basic conditions, the production of intermediate Cr(III)-Fe(III) clusters by light leads to the oxidation of Cr(III) into Cr(VI) through the nonradical "metal-to-metal charge transfer" mechanism. Our study provides a new insight into Cr(VI) reoccurrence in rCOPR and helps in predicting its environmental risk in nature.

Synthesis of Visible-Light-Activated Hypervalent Iodine and Photo-oxidation under Visible Light Irradiation via a Direct S0→Tn Transition.

Heavy atom-containing molecules cause a photoreaction by a direct S0 → Tn transition. Therefore, even in a hypervalent iodine compound with a benzene ring as the main skeleton, the photoreaction proceeds under 365-400 nm wavelength light, where UV-visible spectra are not observed by usual measurement method. Some studies, however, report hypervalent iodine compounds that strongly absorb visible light. Herein, we report the synthesis of two visible light-absorbing hypervalent iodines and their photooxidation properties under visible light irradiation. We also demonstrated that the S0 → Tn transition causes the photoreaction to proceed under wavelengths in the blue and green light region.

Facile Synthesis of Porous g-C3N4 with Enhanced Visible-Light Photoactivity.

Porous graphitic carbon nitride (g-C3N4) was prepared by dicyandiamide and urea via the pyrolysis method, which possessed enhanced visible-light-driven photocatalytic performance. Its surface area was increased from 17.12 to 48.00 m2/g. The porous structure not only enhanced the light capture capacity, but also accelerated the mass transfer ability. The Di (Dicyandiamide)/Ur (Urea) composite possessed better photocatalytic activity for Rhodamine B in visible light than that of g-C3N4. Moreover, the Di/Ur-4:5 composite showed the best photoactivity, which was almost 5.8 times that of g-C3N4. The enhanced photocatalytic activity showed that holes and superoxide radical played a key role in the process of photodegradation, which was ascribed to the enhanced separation of photogenerated carriers. The efficient separation of photogenerated electron-hole pairs may be owing to the higher surface area, O dopant, and pore volumes, which can not only improve the trapping opportunities of charge carriers but also the retarded charge carrier recombination. Therefore, it is expected that the composite would be a promising candidate material for organic pollutant degradation.

Nonylphenol photodegradation by novel ternary MIL-100(Fe)/ZnFe2O4/PCN composite under visible light irradiation via double charge transfer process.

Nonylphenol (NP) residues, as a typical endocrine disrupting chemical (EDC), frequently exist in sewage, surface water, groundwater and even drinking water, which poses a serious threat to human health due to its bioaccumulation. In order to remove NP, a series of MIL-100(Fe)/ZnFe2O4/flake-like porous carbon nitride (MIL/ZC) was synthesized through in-situ synthesis at room temperature. High performance of ternary MIL/ZC is used to degrade NP under visible light irradiation. The results show that 30MIL/ZC2 (20 wt.% ZnFe2O4) ternary composite had the best photocatalytic activity (99.84%) when the dosage was 30 mg. Further mechanism analysis shows that the excellent photocatalytic activity of 30MIL/ZC2 could be ascribed to the double charge transfer process between flake-like porous carbon nitride (PCN) and other catalysts in the ternary heterojunction, and the separation of photogenerated electron-hole pairs was more effective. In addition, the 30MIL/ZC2 also showed high stability after five cycles of the photodegradation reaction. Furthermore, the active substance (•O2-) was considered to be the main active substance in the NP degradation process. Based on the research results, the possible photocatalytic reaction mechanism of 30MIL/ZC2 ternary composite was proposed and discussed in detail.

Spotlight on Photoinduced Aryl Migration Reactions.

Rearrangement reactions are certainly one of the most useful approaches towards complex structures in organic chemistry. With efficient conditions, it is indeed possible to convert simple substrates into highly functionalized products. Moreover, combining this approach with an attractive initiation process, such as visible-light catalysis, makes these reactions particularly powerful. Recently, tremendous improvements have been made, owing to a better understanding of photoredox mechanisms. In this review, recent progress on visible-light aryl migration reactions is discussed, focusing especially on Smiles rearrangement and related reactions.

Microstructures and optical performances of nitrogen-vanadium co-doped TiO2 with enhanced purification efficiency to vehicle exhaust.

Titanium dioxide (TiO2) is widely used to purify air pollutants in environmental engineering, but it is only activated by ultraviolet (UV) light. The metal or nonmetal single doping of TiO2 cannot observably improve the purification efficiency of TiO2 under visible light. To further increase the photocatalytic activity and purification efficiency of TiO2 on vehicle exhaust under visible light, nitrogen (N)-vanadium (V) co-doped TiO2 was first prepared. The influences of N-V co-doping on phase structures, morphology, microstructures, electronic structures, and photo-absorption performances were then observed and examined using X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-visible light diffuse reflectance spectra. Purification efficiency and reaction rates of N-V co-doped TiO2 on NOx, HC, CO and CO2 in vehicle exhaust were studied using a purification test system under UV and visible light irradiations, respectively. Results indicate that N and V are synchronously doped into the crystal structures of TiO2 to replace O and Ti, respectively. N and V show the synergistic co-doping effect to suppress the grain growth of TiO2 and improve the dispersity and specific surface area of TiO2. Also, the N-V co-doping introduces more lattice distortions and defects in the crystal lattices of TiO2. Further, N presents in the form of Ti-O-N and O-Ti-N bonds, and V exists in the form of V5+ and V4+. These form the impurity energy level in the band gap to narrow the energy band of TiO2. Additionally, the N-V co-doping broadens the photoabsorption threshold of TiO2 from 387 nm to 611 nm. These results show that N-V co-doping increases the photocatalytic activity of TiO2. Finally, the N-V co-doped TiO2 shows higher catalytic purification efficiency on NOx and HC under UV and visible light. The N-V co-doping obviously increases the purification efficiency of TiO2 on CO and CO2 when exposed to visible light, and their reversible reactions are not found. The N-V co-doping of TiO2 is a feasible approach to purify vehicle exhaust under visible light irradiations.

Visible-Light-Promoted Ring-Opening Alkynylation, Alkenylation, and Allylation of Cyclic Hemiacetals through ß-Scission of Alkoxy Radicals.

The alkoxy radicals that are derived from cyclic hemiacetals have been generated through the visible-light-promoted reaction of the corresponding N-alkoxyphthalimides with Hantzsch ester as the reductant. The alkoxy radicals subsequently undergo ß-scission of the C-C bond to generate carbon-centered radicals, which are trapped by alkynyl-, alkenyl-, or allylsulfones.