Morbidity and mortality resulting from acute inhalation exposures to hydrogen fluoride and carbonyl fluoride in rats

Recent Advances in the Synthesis and Transformation of Carbamoyl Fluorides, Fluoroformates, and Their Analogues

Carbamoyl fluorides, fluoroformates, and their analogues are a class of important compounds and have been evidenced as versatile building blocks for the preparation of useful molecules in organic chemistry. While major achievements were made in the synthesis of carbamoyl fluorides, fluoroformates, and their analogues in the last half of 20th century, an increasing number of reports have focused on using O/S/Se=CF2 species or their equivalents as the fluorocarbonylation reagents for the direct construction of these compounds from the parent heteroatom-nucleophiles in recent years. This review mainly summarizes the advances in the synthesis and typical application of carbamoyl fluorides, fluoroformates, and their analogues by the halide exchanges and fluorocarbonylation reactions since 1980.

The potential of thermal desorption-GC/MS-based analytical methods for the unambiguous identification and quantification of perfluoroisobutene and carbonyl fluoride in air samples

The reactive gases perfluoroisobutene and carbonyl fluoride are highly toxic and difficult to analyze in air. For this paper, the available sampling and analysis methods involving gas chromatography/mass spectrometry were investigated for their potential to give unambiguous identification and quantification of perfluoroisobutene and carbonyl fluoride, for which no such methods exist. Although high concentrations of perfluoroisobutene could be analyzed directly by manual split injection, sorbent sampling followed by thermal desorption GC/MS allowed lower concentrations to be analyzed. However, a significant degradation of perfluoroisobutene observed after thermal desorption analysis inspired the use of derivatization of perfluoroisobutene with 3,4‐dimercaptotoluene. The use of Tenax TA sorbent tubes spiked with 3,4‐dimercaptotoluene and trimethylamine in a molar ratio of 1:8 proved successful for the quantification of a unique perfluoroisobutene derivative, and the method was validated for atmospheres in the range of 0.13–152 ppb with a relative standard deviation of less than 20% and an accuracy of 90%. Although carbonyl fluoride was less stable than perfluoroisobutene, direct analysis was possible at high concentrations but the response was not linear. The 3,4‐dimercaptotoluene derivatization method developed was also applicable for quantification of carbonyl fluoride atmospheres.

Upcycle hazard against other hazard: Toxic fluorides from plasma fluoropolymer etching turn novel microbial disinfectants

The release of toxic fluoride byproducts is a seemingly unavoidable artifact of surface engineering, causing severe environmental and human health problems. Here we propose and implement a new "upcycle hazard against other hazard" concept in the case study of cold atmospheric plasma surface modification of fluoropolymers such as polytetrafluorethylene (PTFE). Capitalizing on the excellent controllability, precision and energy efficiency of the plasma surface processing, complemented with the recently discovered ability of plasmas to activate water to produce a potent electrochemical disinfectant, referred to as the plasma-activated water (PAW), we demonstrate a radically new solution to capture the hazardous gaseous fluorides into the PAW and use the as-fluorinated PAW (F-PAW) as a very effective antimicrobial disinfectant. A customized surface discharge reactor is developed to evaluate the effects of fluorides released from the plasma etching of PTFE on the chemistries in gas-phase plasmas and F-PAW, as well as the antibacterial effect of F-PAW. The results show that gaseous fluorides, including COF₂, CF₃COF, and SiF₄ are produced in gas-phase plasmas, and the dissolution of thus-generated fluorides into PAW has a strong effect on inactivating catalase and destroying the oxidation resistance of bacterial cells. As a result, the antibacterial effect of PAW-fluorides against the methicillin-resistant Staphylococcus aureus (MRSA) is enhanced by > 5 log reductions, suggesting that otherwise hazardous fluorides from the plasma processing of PTFE can be used to enhance the microbial disinfection efficiency of PAW. The demonstrated approach opens new avenues for sustainable hazard valorization exemplified by converting toxic fluoride-etching products into potent antimicrobial and potentially anti-viral disinfectants.

Interaction of Several Toxic Heterocarbonyl Gases with Polypyrrole as a Potential Gas Sensor

The interactions of the toxic heterocarbonyl gases phosgene, carbonyl fluoride, formaldehyde, carbonyl sulfide, and acetone with polypyrrole as a toxic heterocarbonyl gas sensor, were extensively studied by density functional theory (DFT). The Becke 3-parameter, Lee-Yang-Parr (B3LYP) exchange-correlation functional methods were first tested against several high-level DFT methods employing the Dunning’s double-ζ and triple-ζ basis sets and were found to be sufficient in describing the non-covalent interactions involved in this study. The interaction of pyrrole with the heterocarbonyl gases resulted in changes in the structure and optoelectronic properties of the polymer and it was observed that acetone and formaldehyde had the strongest H-bonding interaction with polypyrrole, while the interaction of phosgene and formaldehyde resulted in the lowest energy gap and may result in its high sensitivity towards these gases. The UV-Vis absorption revealed significant red-shifted first singlet excited states (Eexcited, 1st) of the complexes and follows the same trend as the EGap values. It is shown that the Eexcited, 1st was due to the π(HOMOPy) ⟶ π*(LUMOHC) transitions and the excited state at maximum absorption (Eexcited, max) was due to the π(HOMOPy) ⟶ π*(LUMOPy) transitions. This study demonstrates the potential sensitivity and selectivity of polypyrrole as a toxic heterocarbonyl sensor.