Formation Of CF Research Articles

Comprehensive risk assessment and interactions of fluoride and boron ions in the water-sediments interface: The Red Sea, Egypt

This study presents a baseline evaluation of the distribution, human and ecotoxicological risk, and the potential interactions of fluoride and boron in the water-sediment interface in 25 locations from incredible Red Sea tourist destinations. Results showed comparable levels of B and F in the water and sediments with previous literature. Significant positive correlation was found between B and F (r = 0.57; P<0.01). Based on the sediment/liquid partition coefficient (Kd), F is more likely to be released from the sediment into seawater (logKd< 3) than B (3<logKd< 4). pH and alkalinity may affect water-sediment interactions of B and F, respectively, while SO42− and Cl− ions had no significant effect on adsorption ability of F and B. The majority of minerals had average saturation Index (SI) > 1 referring to the over saturation of seawater with these minerals and their inability to dissolve. The formation of CF, FAP, and CFAP may be related to the high correlation between Fw (r = 0.928, P< 0.01; r = 0.527, P< 0.01; r = 0.608, P< 0.01) and Bw (r = 0.38, P< 0.05; r = 0.38, P< 0.05; r = 0.397, P< 0.05). Total hazard quotient (THQ) for children and adults were <1, revealing no health risks from exposure to B and F through ingestion and skin contact while swimming. The risk characterization ratio; RCRmix(MEC/PNEC) showed high short-term risks to aquatic organisms. Further investigations might emphasis on emerging mitigation strategies to address these concerns.

CREEPING FAT-DERIVED FIBROBLASTS PARTICIPATE IN INTESTINAL FIBROSIS IN A NOVEL MOUSE MODEL OF INTESTINAL STRICTURES

Abstract INTRODUCTION An intestinal stricture is a common morbidity in Crohn's disease, but its pathogenesis is poorly understood. CF forms adjacent to strictures and is associated with stricture recurrence, but whether it promotes stricture formation is unclear. Adipocytes display remarkable plasticity, and adipocyte-derived fibroblasts (ADFs) play important roles in tissue wound healing and fibrosis. Here, we show that CF ADFs may promote intestinal stricture formation. METHODS We developed a novel mouse model of CF and intestinal fibrosis by creating anti-mesenteric colotomies. We then created colotomies in Adipoq-Cre; mTmG mice and harvested the mice at post-operative day (POD) 14. This system exclusively labels adipocytes and their derivatives GFP+, whereas all other cells are TdTomato+ (Figure 1A-B). We immunostained sham and colotomy bowel for mature adipocyte marker PLIN1. We quantified GFP+ lineage-negative ADFs (CD45-CD31-Terr119-EPCAM-ECadherin-) isolated from either sham or colotomy bowel at POD 14. We then isolated ADFs (GFP+) and non-ADFs (nADFs) (TdTomato+) by flow cytometry and performed single-cell RNA-seq (scRNA-seq) (Figure 1F). RESULTS The creation of a colotomy is sufficient to induce localized mesenteric adipose tissue (MAT) expansion around the colotomy site, consistent with CF formation (Figure 1C). We observed the presence of GFP+ cells with a fibroblast morphology that lost the expression of adipocyte markers and acquired the expression of fibroblast markers. (Figure 1D). Furthermore, we observed that GFP+ ADFs expanded in colotomy bowel compared to sham (Figure 1E). scRNA-seq of ADFs and nADFs revealed 5 major fibroblast clusters, including a Clu+ pro-fibrotic population and a Pi16+ progenitor population, which were enriched in bowel GFP+ ADFs (Figure 1G-H). Finally, quantification of gene expression revealed that GFP+ ADFs lacked mature adipocyte markers, expressed fibroblast markers, and were enriched for various ECM proteins. CONCLUSIONS An anti-mesenteric model of intestinal strictures and CF in combination with immunostaining and scRNA-seq revealed that ADFs from CF infiltrate the bowel wall and expand at the site of fibrosis. ADFs exhibit fibroblast heterogeneity and are enriched for pro-fibrotic and stromal progenitor populations. Finally, ADFs produce collagen and fibronectin, suggesting that they may be pro-fibrotic. Altogether, these data highly suggest that CF contains pro-fibrotic stromal cells that infiltrate the stricture site to promote fibrosis.

Mechanistic and kinetic study of the oxidation of trifluoroacetonitrile by hydroxyl and oxygen

AbstractTrifluoroacetonitrile (CF3CN) is one of the perfluoronitriles to be used as replacements for electrical insulation, working fluids, and biomedical applications. Potential energy surfaces for the reactions of CF3CN with OH radicals in the presence of molecular O2 have been calculated in details using the second‐order Møller−Plesset perturbation theory (MP2) and coupled‐cluster theory with single and double substitutions (CCSD) for geometrical optimization, and the restricted open‐shell complete basis set quadratic ROCBS‐QB3, multireference second‐order Rayleigh–Schrodinger perturbation theory extrapolated to complete basis set limit (RS2/CBS), and the explicitly‐correlated RS2 theory (RS2‐F12) for energetics. The CF3CN + OH reaction undergoes predominantly via the CO addition/elimination mechanism, leading to CF3C(OH)N radical adduct followed by the formation of CF3 and HOCN. The OH radicals could be recycled through the interception of CF3C(OH)N by O2 to form the orientation‐dependent CF3C(OH)NO2 radicals, leading to CF3C(O)NO + OH via the successive H‐migration and OO bond fission. Under the typical atmospheric conditions, the OH‐recycling mechanism is dominant for the oxidation of CF3CN. The production of CF3 and HOCN can be significant at high temperatures and low pressures. Theoretical rate coefficients are in excellent agreement with the experimental data. The effect of substitution on the reactivity of the perfluoronitriles toward OH was revealed. The present work provides a fundamental understanding on the degradation of CF3CN and serves as a theoretical basis for its secondary chemistry.

In situ synchrotron X-ray scission of polytetrafluoroethylene chains and elucidation of dry etching

We investigated the mechanism of polytetrafluoroethylene (PTFE) chain scission through in situ hard X-ray photoelectron spectroscopy at room temperature, 200 °C, and 230 °C. The C–C bonds in the main chain and C–F bonds in the side chains were broken, and F desorption from the PTFE surface was observed at room temperature. The formation of CF3 was also observed from the recombination of broken C–C bonds in the main chain and detached F, which were not induced by soft X-rays. In contrast, when the PTFE substrate was irradiated with hard X-rays at 200 °C, the CF3 intensity initially produced by recombination reactions decreased with irradiation time, and the photoelectron spectrum retained the original PTFE spectrum. Under these conditions, the F1s/C1s intensity ratio did not change with the irradiation time; hence, the fragment containing only CF2, the chemical composition of the original PTFE, was desorbed. When the substrate temperature was 230 °C, the CF3 intensity increased in relation to that at 200 °C. This result indicated that the formation of CF3 via recombination reactions of broken molecular chains is enhanced by thermal assistance. These phenomena were considered to be based on the balance between recombination and desorption by photochemical and pyrochemical reactions. These results will lead to a better understanding of the use of X-ray-irradiated fluorine resins and PTFE in potential space-based environments. This study will also promote the improvement of PTFE microfabrication methods and thin-film formation using synchrotron radiation.

Refining the thermochemical properties of CF, SiF, and their cations by combining photoelectron spectroscopy, quantum chemical calculations, and the Active Thermochemical Tables approach.

Fluorinated species have a pivotal role in semiconductor material chemistry and some of them have been detected beyond the Earth's atmosphere. Achieving good energy accuracy on fluorinated species using quantum chemical calculations has long been a challenge. In addition, obtaining direct experimental thermochemical quantities has also proved difficult. Here, we report the threshold photoelectron and photoion yield spectra of SiF and CF radicals generated with a fluorine reactor. The spectra were analysed with the support of ab initio calculations, resulting in new experimental values for the adiabatic ionisation energies of both CF (9.128 ± 0.006 eV) and SiF (7.379 ± 0.009 eV). Using these values, the underlying thermochemical network of Active Thermochemical Tables was updated, providing further refined enthalpies of formation and dissociation energies of CF, SiF, and their cationic counterparts.

A CAFM and device level study of MIS structures with graphene as interfacial layer for ReRAM applications

Capacitive Metal-Insulator-Semiconductor structures with graphene as interfacial layer between the HfO2 dielectric and the top electrode have been fabricated and investigated at device level and at the nanoscale with Conductive Atomic Force Microscope. In particular, their electrical properties and variability have been compared to devices without graphene to evaluate their feasibility as ReRAM devices. At device level, we observe that, when graphene is present as an intercalated layer, several resistive switching cycles can be measured, meanwhile the standard structures without graphene do not show resistive switching behavior. Nanoscale analysis showed that the graphene layer prevents the microstructural irreversible damage of the oxide material during a forming process. Therefore, graphene somehow protects the structure during the CF formation. This protection would explain the observation of RS of the devices with intercalated graphene.

Mechanisms of Formation and Rearrangement of Benziodoxole-Based CF3 and SCF3 Transfer Reagents.

Togni’s benziodoxole-based reagents are widely used in trifluoromethylation reactions. It has been established that the kinetically stable hypervalent iodine form (I–CF3) of the reagents is thermodynamically less stable than its acyclic ether isomer (O–CF3). On the other hand, the trifluoromethylthio analogue exists in the thermodynamically stable thioperoxide form (O–SCF3), and the hypervalent form (I–SCF3) has been elusive. Despite the importance of these reagents, very little is known about the reaction mechanisms of their syntheses, which has hampered the development of new reagents of the same family. Herein, we use density functional theory calculations to understand the reasons for the divergent behaviors between the CF3 and SCF3 reagents. We demonstrate that they follow different mechanisms of formation and that the metals involved in the syntheses (potassium in the case of the trifluoromethyl reagent and silver in the trifluoromethylthio analogue) play key roles in the mechanisms and greatly influence the possibility of their rearrangements from the hypervalent (I–CF3, I–SCF3) to the corresponding ether-type form (O–CF3, O–SCF3).

Evidence of Alpha Radiolysis in the Formation of a Californium Nitrate Complex.

Well-characterized complexes of transplutonium elements are scarce because of the experimental challenges of working with these elements and the rarity of the isotopes. This leads to a lack of structural and spectroscopic data needed to understand the nature of chemical bonds in these compounds. In this work, the synthesis of Cf(DOPOq )2 (NO3 )(py) (DOPOq =2,4,6,8-tetra-tert-butyl-1-oxo-1H-phenoxazin-9-olate; py=pyridine) is reported, in which the nitrate anion is hypothesized to form through the α-radiolysis-induced reaction of pyridine and/or the ligand. Computational analysis of the electronic structure of the complex reveals that the CfIII -ligand interactions are largely ionic.

Study of the formation of interstellar CF+ from the HF + C + →CF+ + H reaction

Study of the formation of interstellar CF+ from the HF + C + →CF+ + H reaction

Nuclear magnetic resonance studies of nanodiamond surface modification

We review Nuclear Magnetic Resonance (NMR) studies of surface modification of nanodiamonds (ND). The spectra of chemically functionalized – fluorinated, chlorinated, hydroxylated, carboxylated and hydrogenated ND show formation of CF, CCl, COH, CCOOH and CH covalent bonds with the surface carbon atoms, respectively. These bonds reveal different chemical shifts that allow distinguishing between them in the NMR spectra. The NMR data are well supported by XPS measurements.Nanodiamond annealing above 600°C results in a surface graphitization, which increases with increasing the annealing temperature.ND particles with grafted paramagnetic copper, cobalt and gadolinium ions are prepared by mixing of aqueous ND suspension with aqueous solutions of transition metal nitrates. Dissociated cations in this mixture undergo ion exchange with hydrogen atoms of the surface carboxyl groups. To evidence the ion grafting to the surface, we developed an effective approach based on the analysis of nuclear spin-lattice relaxation data. These data show noticeable acceleration of 13C and 1H nuclear spin-lattice relaxation, which results from the interaction of carbon and hydrogen nuclear spins of diamond with the unpaired electron spins of paramagnetic ions. This finding provides clear evidence of the binding of Cu2+, Co2+ and Gd3+ ions to the ND surface. The aforementioned approach allows calculating distances between the ions and surface. A model of the positioning of transition and rare-earth metal ions on the ND surface is presented. The NMR data obtained are supported by EPR measurements. Biomedical applications of the studied nanomaterials are discussed.

Enantioselective Formation of CF3-Bearing All-Carbon Quaternary Stereocenters via C-H Functionalization of Methanol: Iridium Catalyzed Allene Hydrohydroxymethylation.

Using an iridium catalyst modified by PhanePhos, CF3-allenes react with methanol to form branched products of hydrohydroxymethylation as single regioisomers with excellent levels of enantiomeric enrichment. This hydrogen autotransfer process enables catalytic enantioselective formation of acyclic CF3-bearing all-carbon quaternary stereocenters in the absence of stoichiometric metals or byproducts.

Effect of UV Irradiation and UV/Chlorine Processes on Trichloronitromethane Formation During Chlorination of Ronidazole

The effect of UV irradiation and UV/chlorine processes on the formation of trichloromethane (CF) and trichloronitromethane (TCNM) from ronidazole (RNZ) disinfection was investigated in this study. Effects of reaction time, pH, and irradiation intensity on disinfection by‐product (DBP) formation were studied during chlorination, UV irradiation, and UV/chlorine processes. The formation potential (FP) of CF and TCNM increased with the increase of chlorination time and reached maximum of 50.6 and 5.0 µg/L, respectively, at pH 8. UV irradiation could increase CF and TCNM formation slightly during post‐chlorination, while the UV/chlorine process could increase the formation potential of TCNM significantly during post‐chlorination with short irradiation time and low UV intensity (e.g., FPTCNM = 459.4 µg/L; UV irradiation: 1.53 mW/cm2 for 20 min). Under UV condition, the formation of CF and TCNM with post‐chlorination increased with the increasing of pH. However, under UV/chlorine condition, the formation of TCNM reached the highest concentration under neutral condition. The DBP formation potential of RNZ during disinfection in the filtered drinking water was also detected. It turned out that disinfection of filtered drinking water with RNZ led to the formation of more DBPs (except the formation of TCNM in the UV/chlorine process) than ultra‐pure water with RNZ only.

Stable Switching in HfO2-Based Crossbar Conducting- Bridge Resistive Switching Memory Device

We propose a new method to improve resistive switching properties in the HfO2 based CBRAM crossbar structure device by inserting a TaN thin layer between the Cu top electrode and HfO2 switching layer. The Cu/TaN/HfO2/TiN device structure exhibits high resistance ratio of OFF/ON states without any degradation in switching during endurance test. The switching mechanism in the Cu/TaN/HfO2/TiN device can be attributed to the conductive bridging of Cu metal ions. Introduction Electrochemical metallization bridge (EMB) RRAM, referred in literature as Conductive Bridge RAM (CBRAM) or Programmable Metallization Cell (PMC), utilizes electrochemical control of nano-scale quantities of metal in thin dielectric films or solid electrolytes to perform the resistive switching operation. Due to key advantages such as scalability, low-voltage, fast-write operation and long endurance lifetime, CBRAM technology has shown considerable progress in recent years [1-4]. However the random nature of formation and rupture of conductive filament makes their formation difficult to control, which results in a large variation of switching voltages and resistance states in CBRAM device. We report a highly efficient and convenient approach to control the formation and rupture of CF by introducing a thin TaN layer between the HfO2RS layer and top electrode (TE). Experimental Process A 10-nm-thick TiN bottom electrode is deposited by atomic layer deposition (ALD). The bottom electrode iss patterned by lithography and reactive-ion etching (RIE). Subsequently, 10 nm thickness HfO2 films as a dielectric layer are also deposited by ALD. Then the dielectric layers on the bottom electrode are removed by lithography and RIE. Finally, 100-nm-thick Ti and Cu top electrodes are deposited by electron-beam evaporation at room temperature and patterned through the liftoff process. Results and Discussion A schematic configuration and top view of the Cu/TaN/HfO2/TiN crossbar device is depicted in Fig. 1. The typical forming processes and switching of the Ti/HfO2/TiN, Cu/HfO2/TiN and Cu/TaN/HfO2/TiN devices are shown in Fig. 2. A large forming voltage of about 6.3 V is observed on the Ti/HfO2/TiN, while only about 2 V is needed to switch the Cu/HfO2/TiN from initial high resistance state to low resistance state. In the Cu/HfO2/TiN device, the forming process involves injection of Cu ions into the HfO2 layer without causing electrical break-down while in the Ti/HfO2/TiN, a soft break-down of the dielectric is part of the forming process. In CBRAM, a Cu cation is the mobile species responsible for resistive switching, instead of an oxygen anion. The switching mechanism is the electrochemical ionization of the mobile species, followed by drift under the applied electric field. The current-voltage characteristics of both O-RRAM and CBRAM are similar, exhibiting voltage-driven forming, set and reset events, as shown in Fig.2. A primary distinction between the two devices is the read ratio. Cells operated with same ICC, show read ratios of ~100x and >1000x for O-RRAM and CBRAM respectively. Figs. 3 show the DC sweep endurance of O-RRAM and CBRAM devices. Clearly, the Cu/TaN/HfO2/TiN device shows much better endurance than the Cu/HfO2/TiN one. The memory window remains > 1000x after 1000 switching cycles in Cu/TaN/HfO2/TiN device. Conclusion The resistive switching mechanism is explained in HfO2 based CBRAM devices. Compared with Ti top electrode, the Cu top electrode structure exhibits higher resistance ratios of HRS/LRS. In addition, the Cu/TaN/HfO2/TiN structure demonstrates the stable DC sweep endurance up to 103 cycles. From the electrical characteristics, the proposed device exhibits the potential for future nonvolatile memory applications.

Quantum-chemical simulation of the gas-phase molecular, thermodynamic, and kinetic parameters of CF, CF2, and CF3 radicals and CF4, C2F2, C2F4, and C2F6 molecules

Enthalpy of formation of gaseous CF, CF2, CF3, CF4, C2F2, and C2F4 molecules in the ground state have been simulated via the ab initio method in the CCSD(T) approximation with extrapolation to full basis and correlation energy. Equilibrium geometry, frequency of normal vibrations, and other parameters of these molecules have been determined; their thermodynamic functions at 0–2000 K were calculated from these data. Constants of the C2F6←→ 2CF3, C2F2←→ 2CF, C2F4←→ 2CF2, CF4←→ CF3 + F, CF4←→ CF2 + F2, and CF3←→ CF2 + F equilibriums have been calculated, and the data on the rate constants in the high-pressure limit have been obtained.

Polyethyleneimine-grafted collagen fiber as a carrier for cell immobilization.

Collagen fiber (CF), an abundant natural biopolymer, features many favorable properties that make it a potential carrier for cell immobilization. In the present investigation, CF was grafted with polyethyleneimine (PEI) using glutaraldehyde (GA) as the cross-linking agent, resulting in the formation of a novel CF based carrier (CF-PEI). The properties of CF-PEI as a carrier were evaluated by the immobilization of Microbacterium arborescens (CICC 20196), which has glucose isomerase (EC 5.3.1.5) activity. It was found that M. arborescens cells immobilized on CF-PEI exhibited higher glucose isomerization than those using activated carbon or anion exchange resin as the carriers. The Michaelis constant (K m) of the isomerization reaction for the CF-PEI-immobilized M. arborescens cells was 0.528 mol/L, which was slightly higher than that of free cells (0.473 mol/L). In addition, the apparent activation energies (E a) of free and immobilized cells on CF-PEI were almost the same at 60 kJ/mol. In an isomerization reaction of glucose to fructose in a fixed-bed reactor, CF-PEI-immobilized M. arborescens cells showed appreciable activity and operational stability. The corresponding isomerization ratio was as high as 41 % for 20 days, and the half-life was about 40 days.

Electronic Structure of Gold Carbonyl Compounds RAuL (R = CF3, BO, Br, Cl, CH3, HCC, Mes3P, SIDipp; L = CO, N2, BO) and Origins of Aurophilic Interactions in the Clusters [RAuL]n (n = 2–4): A Theoretical Study

The bonding nature of CF3AuCO and its clusters [CF3AuCO]n (n = 2–4) (Angew. Chem., Int. Ed. 2011, 50, 6571) have been theoretically investigated with density functional theory (B3LYP, B3LYP-D3, M06-2X, M06-2X-D3, M05-2X, M06L, B3PW91), the Hartree–Fock method (HF), second-order Moller–Plesset perturbation theory (MP2), and the coupled cluster method with perturbative triplets (CCSD(T)) using a series of basis sets. For comparison, larger complexes that have been studied experimentally, [Mes3PAuCO]+ and [SIDippAuCO]+, were also computed. Various ligands as well as their gold clusters [RAuL]2–4 (R = OB, Br, Cl, CH3, HCC; L = CO, N2, OB) were also investigated. The Au–CO bonds consist of electrostatic attraction, Au←CO donation, and Au→CO π-back-bonding components. The LMOEDA results show that the major contributors of RAuL are found to be electrostatic, which linearly correlates with the interaction energy. Electrostatic stabilization is mainly responsible for aurophilic interactions in the formation of CF3...

Pyrolysis of Trifluoromethane over Activated Carbon: Role of the Surface Oxygen Groups

The pyrolysis of CHF3 and CHClF2 over activated carbons was investigated at 823 K, GHSV of 1820 h–1 and pressure of 1 bar. To elucidate the mechanism, activated carbons were treated in H2 at 1123 K, HNO3 solution at 363 K, N2 at 873 K or supported with 4 wt% poly(acrylic acid sodium salt), respectively. The results confirm that following different treatments, the concentration of surface oxygen groups on activated carbons varies dramatically. These surface groups play important roles in the decomposition of CHF3 and the product profiles. It is suggested that carboxylic groups are responsible for the formation of CF3 and ultimately the product C2F6 which results from the coupling of CF3, while the interaction between CHF3 and hydroxyl or lactonic groups leads to the total destruction of CHF3 and production of CO and CO2. Pyrolysis of CHClF2 over activated carbon confirms that surface oxygen groups have no noticeable influence on the reactions of CF2. By contrast, a pure carbon surface is responsible for the disproportionation of CF2 and formation of CF3.

Quartz crystal microbalance with dissipation coupled to on-chip MALDI-ToF mass spectrometry as a tool for characterising proteinaceous conditioning films on functionalised surfaces

Proteinaceous conditioning films (pCFs) are thought to play a key role in microbial adhesion, leading to the fouling of technical and biomedical devices and biofilm formation, which in turn causes material damage or persistent infections, respectively. However, little is definitively known about the process of surface conditioning via proteins. Herein, we demonstrate the potential of quartz crystal microbalance with dissipation coupled to MALDI-ToF mass spectrometry (QCM-D-MALDI) to investigate protein adsorption on different surfaces, enabling both the monitoring of CF formation and the determination of the molecular composition of CFs. After running QCM-D experiments, a subsequent tryptic on chip digestion step allows the identification of the proteins deposited on the sensor chip surface via MALDI-ToF mass spectrometry. Prominent blood plasma proteins, i.e., human serum albumin (HSA), fibrinogen (FG) and fibronectin (FN), were used. Chemically well defined sensor surfaces were prepared, among others, via self-assembled monolayer (SAM) technology. In cases where protein adsorption was observed by QCM-D, the adsorbed proteins were clearly detected and identified using MALDI-ToF/MS for both single-protein solutions of HSA, FG and FN as well as for protein mixtures. However, for equimolar protein mixtures on TiO2 surfaces, only signals attributed to FG and FN were observed in the mass spectra. No signals indicating the presence of HSA could be detected. This finding leads to the assumption that only FG and FN attach to the TiO2 sensor surface under the given experimental conditions.

Tribological properties of hard a-C:H:F coatings

Hydrogenated amorphous carbon thin films containing fluorine (a-C:H:F) have been produced by radio-frequency plasma enhanced chemical vapor deposition by using different F/H ratios in the gas phase. The introduction of fluorine from 0 to 19at.% resulted in a decrease of hydrogen content and to the formation of CF and CF2 bonds. For all the films, Raman analysis showed a typical diamond-like carbon response with an evolution of the structure to larger sp2 clusters with less hydrogen while fluorine content increased. The drop in hardness generally observed in the literature with fluorine introduction was less abrupt here: for a fluorine content up to 6.5at.%, the measured hardness was 28GPa, and for 19at.% of fluorine, value was 20GPa. These are quite high values for a-C:H:F thin films. Moreover, fluorine improved tribological behavior in dry conditions with friction coefficient slightly reduced at low fluorine content and wear rate significantly reduced: divided by two to four than the fluorine free reference coating.

Photochemistry of CF3(CH2)2CHO in air: UV absorption cross sections between 230 and 340 nm and photolysis quantum yields at 308 nm

This work constitutes the first study on the photochemical degradation process of CF3(CH2)2CHO. Firstly, the wavelength and temperature dependence of the UV absorption cross sections, σλ, was determined. The n → π* electronic transition band of CO chromophore was characterized between 230 and 340 nm in the 269–323 K range. A hyperchromic effect was observed in the structured part of the band when the temperature decreases. Maximum σλ = 283, 291 nm at 323 K is ca. 22% larger than those at 269 K. Secondly, the pulsed laser photolysis of a stationary mixture of CF3(CH2)2CHO/cyclohexane (OH-scavenger)/air or N2 was carried out at 308 nm. On-line Fourier transform infrared (FTIR) spectroscopy was employed to monitor the decay of CF3(CH2)2CHO and to obtain the photolysis quantum yield, Φλ = 308 nm, as a function of total pressure (20.5–760 Torr). A slight curvature in the Stern–Volmer plot was observed at pressures lower than 75 Torr. At high pressures, the pressure dependence of Φλ = 308 nm can be described by a Stern–Volmer relationship. Photodissociation of CF3(CH2)2CHO at 308 nm can produce HCO and CF3(CH2)2 radicals (1a), CF3CH2CH3 and CO (1b) and CF3(CH2)2CO radicals and H atoms (1c). HCO radicals are rapidly converted into CO in the presence of O2. Formation of CF3CH2CHO and CF3CH2CH2OH evidences the importance of secondary chemistry involving CF3(CH2)2 radicals formed in channel (1a). Further photodegradation of CF3CH2CHO yields mainly CF3CHO. Small quantities of HC(O)OH were also detected. CF3(CH2)2C(O)OH was only observed in the absence of OH-scavenger, implying that formation of CF3(CH2)2CO radicals in channel (1c) is not an important photolysis pathway. Consequently, photodissociation of CF3(CH2)2CHO in the actinic region is a source of shorter fluorinated oxygenated compounds, but it is not expected to be a source of fluorinated acids.