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Background: Perfluorohexane sulfonate (PFHxS) is a frequently detected per- and polyfluoroalkyl substance in most populations, including in individuals who are pregnant, a period critical for early life development. Despite epidemiological evidence of exposure, developmental toxicity, particularly at realistic human exposures, remains understudied. Objectives: We evaluated the effect of gestational exposure to human-relevant body burden of PFHxS on fetal and placental development and explored mechanisms of action combining alternative splicing (AS) and gene expression (GE) analyses. Methods: Pregnant ICR mice were exposed to 0, 0.03, and 0.3 [micro]g/kg/day from gestational day 7 to day 17 via oral gavage. Upon euthanasia, PFHxS distribution was measured using liquid chromatography-tandem mass spectrometry. Maternal and fetal phenotypes were recorded, and histopathology was examined for placenta impairment. Multiomics was adopted by combining AS and GE analyses to unveil disruptions in mRNA quality and quantity. The key metabolite transporters were validated by quantitative real-time PCR (qRT-PCR) for quantification and three-dimensional (3D) structural simulation by AlphaFold2. Targeted metabolomics based on liquid chromatography-tandem mass spectrometry was used to detect amino acid and amides levels in the placenta. Results: Pups developmentally exposed to PFHxS exhibited signs of intrauterine growth restriction (IUGR), characterized by smaller fetal weight and body length (p Discussion: The findings from this study suggest that exposure to human-relevant very-low-dose PFHxS during pregnancy in mice caused IUGR, likely via downregulating of placental amino acid transporters, thereby impairing placental amino acid transportation, resulting in impairment of placental development. Our findings confirm epidemiological findings and call for future attention on the health risk of this persistent yet ubiquitous chemical in the early developmental stage and provide a new approach for understanding gene expression from both quantitative and qualitative omics approaches in toxicological studies. https://doi.org/10.1289/EHP13217, Introduction Per- and polyfluoroalkyl substances (PFAS) are a large group of fluorine-containing chemicals commonly applied in industrial and commercial products, resulting in ubiquitous presence in the environment (1,2) and attracting [...]

As a typical smart material, ionic polymer metal composite (IPMC) has a sandwich structure, which consists of a base membrane and two thin metallic electrodes on both sides of the [...]

Characterization of fluorinated polymers in MALDI is often unsuccessful because commonly used matrixes, such as 2,5-dihydroxybenzoic acid, Indole acrylic acid, [alpha]-cyano-4-hydroxycinnamic acid, etc., do not desorb/ionize fluorinated polymers efficiently. This could be in part attributed to the unfavorable interaction between the matrix molecules and fluorinated oligomers due to differences in their hydrophobicities. Moreover, the relative cation affinity between the matrix molecules and the fluorinated oligomers may not favor the gas-phase cationization process of the fluorinated oligomers. To overcome these limitations, fluorinated derivates of benzoic acid (pentafluorobenzoic acid) and cinnamic acid (Pentafluoro cinnamic acid) were employed for the desorption/ionization of perfluoropolyethers. Presence of fluorine atoms in the matrix might improve the interaction between the matrix and perfluoroether during the crystallization or ionization step. With a pentafluorobenzoic acid matrix, intact silver cationized oligomers were desorbed, whereas with a pentafluorocinnamic acid matrix, loss of end group was observed. This loss could be rationalized by the dissociation of the silver cationized oligomers via an ion--dipole mechanism. This work shows the possibility of characterizing yet another important class of fluorinated polymer by MALDI-TOFMS.

This article describes the synthesis, structure, and thermal decomposition of the lanthanide compounds with SC(sub)6F(sub)5 ligands. The fluorinated lanthanide thiolates are used in the synthesis of lanthanide coordination complexes possessing photoemission properties.

Research demonstrates a synthetic route for the preparation of partially fluorinated propargylic and allenic compounds employing water-soluble substrates. Data further show that difluoroallene and allene intermediates are useful in the assembly of gem-difluoroallenes.

Ab initio quantum mechanics and transition-state theory (TST) were employed to obtain the temperature dependence of rate constants for the reactions of OH with CH4, CH3F, CH2F2 and CHF3. Rate constants computed through HF/6-31G(d) frequencies and MP2(full)/6-31G(d) structures to analyze reactant and transition-state partition functions and the Hartree-Fock imaginary frequency to calculate Eckart tunneling factors, produced rate constants that were much larger compared to empirical values.

The role played by C-H***F interactions in the crystal structures of fluorobenzenes has been studied. The significance of the C-F group in crystal packing has also been analyzed in order to understand the binding of a fluorinated substrate to a macromolecular receptor. F***F interactions have further been examined to assess their value in the chemistry of fluorobenzenes. Results show that C-H***F interactions are as important as C-H***O and C-H***N hydrogen bonds in stabilizing fluorobenzene crystals.

The chemical bonding and the electronic structures of C60F(sub x) and C70F (sub x) were studied through near edge X-ray absorption fine structure spectroscopy and UV photoemission spectroscopy. The energies of the LUMO and the Fermi level of solid C60F48 were calculated to be -5.0 and -5.4 eV below the vacuum level, suggesting that highly doped C60F(sub x) is a strong electron acceptor. The electronic absorption spectra of C60F(sub x) solutions deep into the vacuum ultraviolet spectra were also obtained.

Trisubstituted fluoroalkenes were synthesized by the reaction of organolithium reagents to trifluoromethyl enol ethers and thio enol ethers. The course of the reaction of nonterminal CF3-substituted vinylic compounds with organolithium reagents reagents is strongly dependent on the substitution pattern. The formation of E-trisubstituted fluoroolefins also involved the instantaneous stereoselective elimination of lithium ethoxide/thioethoxide.

The reactivity of (C5Me5)Rh(PMe3)H2 with different fluoroaromatic compounds was analyzed to determine its performance in thermal selective C-F activation with polyfluoroaromatic compounds. Analysis of the reaction mechanisms involving C-F cleavage in polyfluorinated aromatic substrates indicated the significant contribution of the fluoride ion on the rate of reaction with polyfluoroaromatics. Furthermore, the organometallic complex was capable of thermally and selectively cleaving the C-F bonds of the polyfluoroaromatics.

A novel method for the synthesis of 19-fluororetinal and 2-fluororetinal was developed based on the utilization of N-methoxy-N-methylamide as a starting material. The synthetic strategy for the formation of 19-derivatized retinals containing a fluoromethyl group involved the formation of alpha-chloromethyl ketone from the reaction of N-methoxy-N-methylamide with methyllithium. The selective introduction of fluorine into the versatile intermediate was based on the reaction of enol acetates and enol silyl agents.

The radical coupling reaction of diphenylbenzo(k)fluoranthene was analyzed by chemiluminescence and voltammetry to determine the electrochemical characteristics of the two monomer units. The formation of bis-4,4'-(7,12-diphenyl)benzo(k)fluoranthene involves the oxidation of (7,12-diphenyl)benzoq[kq]fluoranthene via an oxidation-dehydrogenative coupling-intermediate oxidation pathway. However, a slower intramolecular dehydrogenerative coupling reaction was detected in the dication of bis-4,4'-(7,12-diphenyl)benzo(k)fluoranthene.

The GAUSSIAN86 and GAUSSIAN92 programs were utilized for the molecular orbital calculations of organofluorosilicates such as PhSiF3, PhSiFsub4sup-. Analysis of the optimized geometry of organofluorosilanes and -silicates indicated the role of an Si--F--Si bridged intermediate in mediating the cleavage of the Si-F bonds. On the other hand, the cleavage of the Si-C bonds of the organofluorosilanes is mediated by the radical anion, PhSiFsub5sup-.

The reaction of 4-HC6F4OSiMe3 and C6F5OSiMe3 with hexamethyldisilazane led to the synthesis of stable polysubstituted tetrafluoro- and pentafluorophenylsiloxane. The polyfluorinated aromatic sylil ethers exhibited similar reactivity toward electrophiles without altering the nucleophilicity of oxyge during the replacement of para-hydrogen by fluorine. Furthermore, 4-HC6F4OSiMe3 and C6F5OSiMe3 exhibited increasing reactivity toward substituted pentafluorobenzenes due to the C6F6 < C6F5CF3 < C6F5CN < C6F5NO2 order of the substituent.

The photolysis of O2 with NO2 and (FCO)2 followed by trap-to-trap condensation with O3 and AsF5 led to the synthesis of FC(O)OONO2 as a colorless liquid. The inorganic peroxide is composed of FC(O)OO and O2NOO units that are arranged in planar coordination. Gas electron diffusion also indicated a skew structure with short O-O bonds. Furthermore, the compound exists as a syn conformer at room temperature.

Trisubstituted fluoroalkenes were synthesized by the reaction of organolithium reagents to trifluoromethyl enol ethers and thio enol ethers. The course of the reaction of nonterminal CF3-substituted vinylic compounds with organolithium reagents reagents is strongly dependent on the substitution pattern. The formation of E-trisubstituted fluoroolefins also involved the instantaneous stereoselective elimination of lithium ethoxide/thioethoxide.

The reaction of ReO2F3 with B(OTeF5)3 in Freon-114 led to the formation of ReO2(OTeF5)3. The product was also treated with [N(CH3)4+][OTeF5-] and SO2ClF to produce [N(CH3)4+][ReO2(OTeF5)4-]. Spectroscopic analysis of ReO2(OTeF5)3 indicated the presence of fluorine ligands to the axial and equatorial OTeF5 ligands of the Re(VII) derivatives. Spectroscopic analysis of [N(CH3)4+][cis-ReO2(OTeF5)4-] indicated the presence of a pseudooctahedral cis geometry.

The dehydrobromination of 1,3-dibromo-1,1-difluoro compounds, (4,4-difluoro-1,3-butadienyl)benzene and (E)-1,1-difluoro-1-bromo-2-alkenes with 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) produced E isomers. The production of E isomers was due to the conformational preference of anti-1,3-dibromo-1,1-difluoro compounds. The diene also produced trifluoromethyl compounds when treated with excess DBU due to the flouride attack on the dienes.

The reaction of 1,3-bis(bromomethyl)-2-fluorobenzene with diaza-18-crown-6 produced novel fluoro cryptands and fluoro crown ethers in excellent yields. Analysis of the stability constants of the metal complexes of the fluoromacrocycles of these ethers and their fluorine free relatives suggests that the fluorine-containing macrocycles formed more stable metal complexes than the analogous fluorine free systems.

The HF-BF3 complex is a feebly bound donor-acceptor adduct with intermolecular B-F distance shorter than the total van der Waals radii. The fluorine of HF occurs adjacent to the C3 axis of the BF3 unit, and the proton is away from the intermolecular axis. The ground vibrational state of the complex is symmetrical due to fast vibrational averaging. Minimum intermolecular potential energy surface correspond to the staggered configurations.

The synthesis and structure of sodium yttrium fluoroalkoxides is described. These mixed-metal oxides are used in the manufacture of superconductors. The Y-Na compounds synthesized contain a distorted octahedral around the yttrium ion, which creates a volatile compound that is stable upon deposition.

The electrostriction and piezoelectric effects are observed before poling in the thin film copolymer of vinylidene-fluoride (PVDF) and trifluoroethlene (TrFe), when the film is annealed below the melting point of the copolymer. The electrostriction effect is observed before the polling and the piezoelectric effect after the polling, when the film is annealed above the melting point. The simultaneous existence of both the electrostriction and piezoelectric effect is due to the dipole of the PVDF molecule orientation during the hydrodynamic flow with TrFe molecules.

Simple substitution reactions enable the preparation of fluoro-substituted bis(salicylaldehyde) ethylenediimine (Salen) complexes of copper(II), nickel(II) and oxovanadium(IV). Fluoro substitution significantly influences the packing and mesogenic properties of metallomesogens. Substitution of CH2 for the alkoxy O atom in Ni(5-(hexyloxy)Salen) induces significant structural change from roughly planar to an irregular S-shape. X-ray studies help determine the crystal structure of the mesogen Ni(5-hexylSalen).

A number of phosphorylated fluorochromes were synthesized and tested for the alkaline phosphatase-linked fluorescence assay of membrane-bound nucleic acids. 3-Hydroxy-N-2'-biphenyl-2-naphthalenecarboxamide phosphate ester (HBNP) was found to be the most suitable for the assay. Nonfluorescent HBNP is hydrolyzed by phospholipase bound to the probe DNA to the highly fluorescent 3-hydroxy-N,2'-biphenyl-2-naphthalenecarboxamide (HBN). HBN is insoluble enough in aqueous medium to precipitate on the nylon membrane. Spots containing as little as 5 fg of [lambda] DNA can be successfully detected on the membrane with HBNP.

A white, crystalline solid PF(super -)(sub 4) salt, which was prepared from N(CH3)4F and PF3, exhibited thermal stability upto 150 degrees centigrade, after which it decomposed to CH3F, PF3 and N(CH3). The pseudo-trigonal bipyramidal structure of this PF(super -)(sub 4) anion consisted of two short equatorial bonds and a free valence electron pair that was sterically active.

(Gamma, gamma-difluoroallyl)carbonyl compounds are prepared in a new and easy way formulated by reductive dechlorination, preceded by the introduction of 1,1, 2-trichloro-2,2-difluoroethyl radical, which is stimulated by Ru(II)- or Cu(I), to silyl enol ethers and ketene silyl acetal. Carbonyl compounds are not formed easily by other methods and the preparation of biologically active fluorinated compounds can be carried out by this method.

A study was conducted to examine the phase relations of glaucophanic amphiboles. The synthetic system Na2O-MgO-Al2O3-SiO2-SiF4 (NMASF) was applied using the bulk composition of fluor-glaucophane, Na2Mg3Al2Si8O22F2 (NMASH). NMASH exhibited analogous phase relations with NMASF because SiF4 assumed the role of water as the fluid component. Results show that glacouphane stoichiometry approach in natural systems indicate preference for high water activites and high pressures.