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The title compound, C10H10FNO3, also known as [4-((4-fluorophenyl)amino)-4-oxobutanoic acid] (BFAOB), is synthesized efficiently, and its structure is confirmed by the SC-XRD technique, which indicates that two crystallographically different molecules are present in the asymmetric unit. The fluorobenzene ring is oriented at a dihedral angle of 76.09 (9)° and 23.7 (2)° with respect to acetamide moiety in the first and second types of molecule, respectively. A molecular overlay plot is employed to explore the difference between two types of molecules. Strong hydrogen bonding of type N–H…O, O–H…O and comparatively weak hydrogen bonding of type C-H…O stabilize the crystal packing. The titled compound is also characterized by powder XRD. Hirshfeld surface inspection is carried out to explore the non-covalent interactions that are responsible for crystal packing. DFT calculations demonstrate the high stability of BFAOB crystal compound.

A new type of catalyst for reactions via σ-bond activation is Rh(PAlP): Rh-Al heterobimetallic complex of diphosphine-based tridentate pincer-type PAlP ligand bearing an aluminyl moiety at the center coordination site. This work reports results of theoretical and computational studies of the unique Rh–Al direct bond, flexible behavior of Rh(PAlP) for substrate coordination, and new catalytic functions of Rh(PAlP) via the C–H and C–F σ-bond activations. It is particularly interesting that the Rh-Al bond exhibits an unusual Rhδ−–Alδ+ polarization of the Rh–Al σ-bonding MO, opposite to Mδ+–Lδ− polarization of the usual coordinate bond. The other characteristic feature of PAlP is its strong trans-influence, which is as strong as that of SiMe3 ligand but much stronger than that of CH3 ligand. Because the Al atom of PAlP plays a role of a Lewis acid in Rh(PAlP), Rh(PAlP) has three coordination sites: Al site, Rh axial site, and Rh equatorial site. There, NH3 coordinates to the Al site and the Rh axial site with similar stability, whereas CO coordinates to the Rh axial site and C2H4 coordinates to the Rh equatorial site. Electrostatic interaction plays a crucially important role in the NH3 coordination to the Al site. Rh(PAlP) catalyses conversion of fluorobenzene to benzoic acid via C–F σ-bond cleavage and C(2)-regioselective alkylation of pyridine with alkene via C–H σ-bond activation. Theoretical studies show clearly that the Rh and Al sites participate cooperatively in C–F and C–H σ-bond activations. The unusual Rhδ−–Alδ+ polarization and coordination flexibility play important roles in these catalytic reactions.

The oxidation of benzene, fluorobenzene, chlorobenzene, and phenol in the presence of O2 and N2O on HZSM-5 type zeolite with Si/Al = 24 was studied by EPR spectroscopy. It was shown that the thermal decomposition of nitrous oxide on zeolite forms molecular and chemisorbed atomic oxygen. It was found that the catalytic oxidation of benzene, fluorobenzene, chlorobenzene, and phenol under the action of О2 and N2O proceeds at Lewis acid sites and leads to the formation of phenoxyl radical cations with characteristic g factors and hyperfine structure of the EPR spectrum.

The pressure dependence of the solubility of hydrophobic solutes in aqueous solutions is equivalent to volume changes upon hydrophobic hydration. This phenomenon has been attributed to the packing effects induced by the van der Waals volume difference between the solute and water. However, the volume changes may also be related to the chemical properties of the solute. In this study, we investigated hydrophobic hydration using a series of halogenated benzenes. Solution density measurements revealed negative volume changes for benzene, fluorobenzene, and chlorobenzene, whereas those for bromobenzene and iodobenzene were positive. Subsequent volumetric analyses demonstrated that the relationship between the excess particle number for hydration water and the van der Waals volume for bromobenzene and iodobenzene significantly deviated from the universal line for hydrophobic solutes. This behavior suggests that the volume changes are due to factors other than the packing effect with bromo and iodine functional groups acting as modulators of the hydration structure, resulting in enhanced water depletion.

Ezetimibe is an effective cholesterol absorption inhibitor approved for the combined treatment with statins to reduce LDL-C level. Ezetimibe labeled with deuterium was applied for drug metabolism studies. [2H5] fluorobenzene was applied to preprare [2H4] ezetimibe. Stable isotope labeled ezetimibe was obtained in seven steps with a 29.3% overall yield. Stable isotope labeled glucuronide-ezetimibe, the most abundant metabolite of ezetimibe was also synthesized.

Azaperone, with anti-anxiety and anti-aggressive activities used in veterinary medicine, is a member of the butyrophenone class. It is ordinarily utilized for a wide range of indications, such as sedation, obstetrics, and anesthesia. In this research, an improved synthetic route is presented for azaperone using a phase-transfer catalyst(PTC). In general, it was synthesized as a dopamine antagonist in four steps. The bis(2-chloroethyl) amine intermediate is easily obtained after the conversion of the alcohol groups into the chloride leaving group using thionyl chloride(95% yields). The alkylation of commercially available 2-amino pyridine in the presence of PTC was then carried out, giving 1-(pyridin-2-yl) piperazine with 75% yield. 1-(Pyridin-2-yl) piperazine was finally alkylated using 4-chloro-1-(4-fluorophenyl) butan-1-one to achieve azaperone with 60% yield. The butyrophenone intermediate was obtained via the Friedel-Crafts reaction of fluorobenzene with 4-chlorobutyryl chloride in the presence of AlCl3. High efficiency, gentle reaction conditions, and fast and simple procedure are the advantages of this method. Also, the electrochemical oxidation behaviour of azaperone was investigated using cyclic and differential pulse voltammetry techniques. Cyclic voltammetric studies indicated an irreversible process for azaperone electro-oxidation with a peak potential of 0.78 V in a phosphate buffer solution(pH=7.0) vs. Ag/AgCl(saturated KCl) electrode. The value of the peak current vs. the azaperone concentration was enhanced linearly in the range of 10–70 µmol/L, and the detection limit was found to be 3.33 µmol/L.

Ferroelectric spin crossover (SCO) behavior is demonstrated to occur in the cobalt(II) complex, [Co(FPh-terpy)2 ](BPh4 )2 ⋅3ac (1⋅3 ac; FPh-terpy=4'-((3-fluorophenyl)ethynyl)-2,2':6',2''-terpyridine) and is dependent on the degree of 180° flip-flop motion of the ligand's polar fluorophenyl ring. Single crystal X-ray structures at several temperatures confirmed the flip-flop motion of fluorobenzene ring and also gave evidence for the SCO behavior with the latter behavior also confirmed by magnetic susceptibility measurements. The molecular motion of the fluorobenzene ring was also revealed using solid-state 19 F NMR spectroscopy. Thus the SCO behavior is accompanied by the flip-flop motion of the fluorobenzene ring, leading to destabilization of the low spin cobalt(II) state; with the magnitude of rotation able to be controlled by an electric field. This first example of spin-state conversion being dependent on the molecular motion of a ligand-appended fluorobenzene ring in a SCO cobalt(II) compound provides new insight for the design of a new category of molecule-based magnetoelectric materials.

International audience; The photochemical activation of dimagnesium(I) compounds, and subsequent high yielding, regioselective reactions with inert arenes are reported. Irradiating benzene solutions of [{((Ar)Nacnac)Mg}(2)] ((Ar)Nacnac=[HC(MeCNAr)(2)](-); Ar=2,6-diisopropylphenyl (Dip) or 2,4,6-tricyclohexylphenyl (TCHP)) with blue or UV light, leads to double reduction of benzene and formation of the "Birch-like" cyclohexadienediyl bridged compounds, [{((Ar)Nacnac)Mg}(2)(mu-C6H6)]. Irradiation of [{((Dip)Nacnac)Mg}(2)] in toluene, and each of the three isomers of xylene, promoted completely regio- and chemo-selective C-H bond activations, and formation of [((Dip)Nacnac)Mg(Ar ')] (Ar '=meta-tolyl; 2,3-, 3,5- or 2,5-dimethylphenyl), and [{((Dip)Nacnac)Mg(mu-H)}(2)]. Fluorobenzene was cleanly defluorinated by photoactivated [{((Dip)Nacnac)Mg}(2)], leading to biphenyl and [{((Dip)Nacnac)Mg(mu-F)}(2)]. Computational studies suggest all reactions proceed via photochemically generated magnesium(I) radicals, which reduce the arene substrate, before C-H or C-F bond activation processes occur.

A fluorobenzene based single electron transistor (SET) has been investigated for the detection of toxic gases viz. NH3, HCN, AsH3, and COCl2, within the framework of density functional theory (DFT) formalism based first-principles approach. Initially, the adsorption mechanism between the fluorobenzene quantum dot and the toxic gases (NH3, HCN, AsH3, and COCl2) has been analyzed in terms of adsorption energy, distance of adsorption, DOS profiles and the charge transfer analysis. Later, the exclusive property of charge stability diagram of SET has been utilized to provide the necessary electronic fingerprints for detection of toxic gases. The results suggest that the fluorobenzene SET can be a potential sensor for proposed toxic gases based on the wide operational temperature range and high detection ability as witnessed from the electronic fingerprints.

Metal-free N- and O-arylation reactions of pyridin-2-ones as ambident nucleophiles have been achieved with diaryliodonium salts on the basis of base-dependent chemoselectivity. In the presence of N,N-diethylaniline in fluorobenzene, pyridin-2-ones were very selectively converted to N-arylated products in high yields. On the other hand, the O-arylation reactions smoothly proceeded with the use of quinoline in chlorobenzene, leading to high yields and selectivities. In these methods, a variety of pyridin-2-ones in addition to pyridin-4-one and a set of diaryliodonium salts were accepted as suitable reaction partners., Chemical Science, 11(31), pp.8295-8300; 2020

A linear gold-atom geometry defined by phosphane-P and thiol­ate-S atoms is found in the title compound. The packing is stabilized by a combination of fluoro­benzene-C—H⋯O(meth­oxy), phenyl-C—H⋯F, phenyl-C—H⋯S(thiol­ate) and phenyl-C—H⋯π(fluoro­benzene, phen­yl) inter­actions to generate a three-dimensional network., The title phosphanegold(I) thiol­ate, C26H22AuFNOPS or [Au(C8H7FNOS)(C18H15P)], has the AuI centre coordinated by phosphane-P [2.2494 (8) Å] and thiol­ate-S [2.3007 (8) Å] atoms to define a close to linear geometry [P—Au—S = 176.10 (3)°]. The thiol­ate ligand is orientated so that the meth­oxy-O atom is directed towards the Au atom, forming an Au⋯O close contact of 2.986 (2) Å. In the crystal, a variety of inter­molecular contacts are discerned with fluoro­benzene-C—H⋯O(meth­oxy) and phenyl-C—H⋯F inter­actions leading to dimeric aggregates. These are assembled into a three-dimensional architecture by phenyl-C—H⋯S(thiol­ate) and phenyl-C—H⋯π(fluorobenzene, phen­yl) inter­actions. Accordingly, the analysis of the calculated Hirshfeld surface shows 30.8% of all contacts are of the type C⋯H/H⋯C but this is less than the H⋯H contacts, at 44.9%. Other significant contributions to the surface come from H⋯F/F⋯H [8.1%], H⋯S/S⋯H [6.9%] and H⋯O/O⋯H [3.2%] contacts. Two major stabilization energies have contributions from the phenyl-C—H⋯π(fluoro­benzene) and fluoro­benzene-C—H⋯C(imine) inter­actions (−37.2 kcal mol−1), and from the fluoro­benzene-C—H⋯F and phenyl-C—H⋯O inter­actions (−34.9 kcal mol−1), the latter leading to the dimeric aggregate.

This paper describes a new flow-through capillary sample holder that allows the in situ study of re-solvation processes. The holder can be aligned to the goniometer's center using two perpendicular micrometric tables that move in y and z directions. The re-solvation of two ibrutinib solvates of anisole and fluorobenzene was tested using the holder to show the practical application of this technique.

1 : 1 mixtures of aminomethylenehelicene (P)-tetramer and (M)-pentamer with terminal C16 alkyl groups in fluorobenzene showed structural changes between hetero-double-helices B and C and random-coils 2A. Figure-eight thermal hysteresis appeared when the solution was cooled and heated at a constant rate and involved the crossing of cooling and heating curves in Δe/temperature profiles. This unusual thermal hysteresis emerged in the intermediate state between counterclockwise and clockwise thermal hystereses. This phenomenon arose from the competition between self-catalytic reactions to form B and C from 2A. Significant effects of terminal C16 alkyl groups on the thermodynamic and kinetic phenomena are also described.

We demonstrate the performance of a dual frequency comb quantum cascade laser (QCL) spectrometer for the application of vibrational Stark spectroscopy. Measurements performed on fluorobenzene with the dual-comb spectrometer (DCS) were compared to results obtained using a conventional Fourier transform infrared (FT-IR) instrument in terms of spectral response, parameter estimation, and signal-to-noise ratio (S/N). The dual-comb spectrometer provided similar qualitative and quantitative data as the FT-IR setup in 250 times shorter acquisition time. For fluorobenzene, the DCS measurement resulted in a more precise estimation of the fluorobenzene Stark tuning rate ((0.81 ± 0.09) cm−1/(MV/cm)) than with the FT-IR system ((0.89 ± 0.15) cm−1/(MV/cm)). Both values are in accordance with the previously reported value of 0.84 cm−1/(MV/cm). We also point to an improvement of signal-to-noise ratio in the DCS configuration. Additional characteristics of the dual-comb spectrometer applicable to vibrational Stark spectroscopy and their scaling properties for future applications are discussed.

The synthesis of a boryl-substituted germanium(II) cation, [Ge{B(NDippCH)2 }(IPrMe)]+ , (Dipp=2,6-diisopropylphenyl) featuring a supporting N-heterocyclic carbene (NHC) donor, has been explored through chloride abstraction from the corresponding (boryl)(NHC)GeCl precursor. Crystallographic studies in the solid state and UV/Vis spectra in fluorobenzene solution show that this species dimerizes under such conditions to give [(IPrMe){(HCNDipp)2 B}Ge=Ge{B(NDippCH)2 }(IPrMe)]2+ (IPrMe = 1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene), which can be viewed as an imidazolium-functionalized digermene. The dimer is cleaved in the presence of donor solvents such as [D8 ]thf or [D5 ]pyridine, to give monomeric adducts of the type [Ge{B(NDippCH)2 }(IPrMe)(L)]+ . In the case of the thf adduct, the additional donor is shown to be sufficiently labile that it can act as a convenient in situ source of the monomeric complex [Ge{B(NDippCH)2 }(IPrMe)]+ for oxidative bond-activation chemistry. Thus, [Ge{B(NDippCH)2 }(IPrMe)(thf)]+ reacts with silanes and dihydrogen, leading to the formation of GeIV products, whereas the cleavage of the N-H bond in ammonia ultimately yields products containing C-H and B-N bonds. The facile reactivity observed in E-H bond activation is in line with the very small calculated HOMO-LUMO gap (132 kJ mol-1 ).

The synthesis and full characterization of α-silylated (α-SiCPs; 1–7) and α-germylated (α-GeCPs; 11–13) phosphorus ylides bearing one chloride substituent R$_{3}$PC(R$^{1}$)E(Cl)R$^{2}$$_{2}$ (R=Ph; R$^{1}$=Me, Et, Ph; R$^{2}$=Me, Et, iPr, Mes; E=Si, Ge) is presented. The molecular structures were determined by X-ray diffraction studies. The title compounds were applied in halide abstraction studies in order to access cationic species. The reaction of Ph$^{3}$PC(Me)Si(Cl)Me$^{2}$ (1) with Na[B(C$^{6}$F$^{5}$)$^{4}$] furnished the dimeric phosphonium-like dication [Ph$^{3}$PC(Me)SiMe$^{2}$]$^{2}$[B(C$^{6}$F$^{5}$)$^{4}$]$^{2}$ (8). The highly reactive, mesityl- or iPr-substituted cationic species [Ph$^{3}$PC(Me)SiMes$^{2}$][B(C$^{6}$F$^{5}$)$^{4}$] (9) and [Ph$^{3}$PC(Et)SiiPr$^{2}$][B(C$^{6}$F$^{5}$)$^{4}$] (10) could be characterized by NMR spectroscopy. Carrying out the halide abstraction reaction in the sterically demanding ether iPr$^{2}$O afforded the protonated α-SiCP [Ph$^{3}$PCH(Et)Si(Cl)iPr$^{2}$][B(C$^{6}$F$^{5}$)$^{4}$] (6 dec) by sodium-mediated basic ether decomposition, whereas successfully synthesized [Ph$^{3}$PC(Et)SiiPr$^{2}$][B(C$^{6}$F$^{5}$)$^{4}$] (10) readily cleaves the F−C bond in fluorobenzene. Thus, the ambiphilic character of α-SiCPs is clearly demonstrated. The less reactive germanium analogue [Ph$^{3}$PC(Me)GeMes$^{2}$][B{3,5-(CF$^{3}$)$^{2}$C$^{6}$H$^{3}$}$^{4}$] (14) was obtained by treating 11 with Na[B{3,5-(CF$^{3}$)$^{2}$C$^{6}$H$^{3}$}$^{4}$] and fully characterized including by X-ray diffraction analysis. Structural parameters indicate a strong C$^{Ylide}$−Ge interaction with high double bond character, and consequently the C−E (E=Si, Ge) bonds in 9, 10 and 14 were analyzed with NBO and AIM methods.

Exploiting chemical cooperation between Na and Fe(II) within the bimetallic base [dioxane ⋅ NaFe(HMDS) 3] (I), (dioxane=1,4-dioxane, HMDS=N(SiMe 3) 2) the selective ferration of fluorobenzene, 1-fluoronaphthalene, 1,4-difluorobenzene, 1,2,4-trifluorobenzene, 1,3,5-trifluorobenzene, 1-bromo-3,5-difluorobenzene, 3-fluoroanisole and 3,5-difluoroanisole has been realized, affording sodium ferrates [dioxane ⋅ Na(HMDS)(2-F-C 6H 4)Fe(HMDS)] ∞ (1), [dioxane ⋅ Na(HMDS)(2-F-C 10H 6)Fe(HMDS)] ∞ (2), [dioxane ⋅ {Na(HMDS)(2,5-F 2-C 6H 3)Fe(HMDS)} 2] ∞ (3), [dioxane ⋅ {Na(HMDS)(2,3,6-F 3-C 6H 2)Fe(HMDS)} 2] ∞ (4), [(dioxane) 1.5 ⋅ Na(HMDS)(2,4,6-F 3-C 6H 2)Fe(HMDS)] 2 (5), [(dioxane) 1.5 ⋅ {Na(HMDS)(4-Br-2,6-F 2-C 6H 2)Fe(HMDS) 2] (6), [{(dioxane) 2 ⋅ Na 2Fe(HMDS) 2(2-methoxy-6-F-C 6H 3)} +{Fe(HMDS) 3} −] ∞ (7) and [dioxane ⋅ {Na(HMDS)(4-methoxy-2,6-F 2-C 6H 2)Fe(HMDS)} 2] ∞ (8), respectively. Reactions take place under mild reaction conditions, with excellent control of the selectivity and no competing C−F bond activation is observed. Showcasing complex polymeric arrangements in some cases, the structures of compounds 1–8 have been determined by X-ray crystallographic studies. In all cases, the Fe(II) centers occupy the position in the relevant fluoroarene that was previously filled by a proton, confirming that these metallations are actually ferration processes whereas the Na atoms prefer to form Na⋅⋅⋅F dative interactions. Compounds 1–8 are thermally stable and do not undergo benzyne formation (through NaF elimination) and their formation contrasts with the inertness of Fe(HMDS) 2 which fails to act as a base to metallate fluoroarenes.

Materials that both sequester chemical warfare agents (CWAs) and then catalytically decontaminate the entrapped CWAs are highly sought. This article reports such a system for air-based catalytic removal of the sulfur mustard (HD) simulant, 2-chloroethyl ethyl sulfide (CEES). Hypercrosslinked polymers (HCPs) sequester CEES, and an HCP-embedded oxidation system comprising tribromide, nitrate, and acid (NOxBrxH+) simultaneously catalyzes the aerobic and selective, oxidative conversion of the entrapped CEES to the desired far less-toxic sulfoxide under ambient conditions (air and temperature). (NOxBrxH+) has been incorporated into three HCPs, a fluorobenzene HCP (HCP-F), a methylated HCP (HCP-M), and an HCP with acidic moieties (HCP-A). HCP-A acts as both an absorbing material and a catalytic component due to its acidic side chains. All three HCP/NOxBrxH+ systems work rapidly under these optimally mild conditions. No light or added oxidants are required. The HCP/NOxBrxH+ systems are recyclable.

Previously published experimental viscosity data at low density, originally obtained using all-quartz oscillating-disk viscometers for R134a and six vapors of aromatic hydrocarbons in the temperature range between 297 K and 631 K at most, were re-evaluated after an improved re-calibration. The relative combined expanded ($$k=2$$ k = 2 ) uncertainty of the re-evaluated data are 0.2 % near room temperature and increases to 0.3 % at higher temperatures. The re-evaluated data for R134a as well as for the vapors of mesitylene, durene, diphenyl, fluorobenzene, chlorobenzene, and p-dichlorobenzene were arranged in approximately isothermal groups and converted into quasi-isothermal viscosity data using a first-order Taylor series in temperature. Then, the data for R134a were evaluated by means of a series expansion truncated at first order to obtain the zero density and initial density viscosity coefficients, $$\eta ^{(0)}$$ η ( 0 ) and $$\eta ^{(1)}$$ η ( 1 ) . For the six aromatic vapors, the Rainwater–Friend theory for the initial density dependence of the viscosity was used to derive $$\eta ^{(0)}$$ η ( 0 ) values. Finally, reliable $$\eta ^{(0)}$$ η ( 0 ) and also $$\eta ^{(1)}$$ η ( 1 ) values for R134a were selected as reference values in the measured temperature range to be applied when generating a new viscosity formulation.

For benzene, toluene, aniline, fluorobenzene, and phenol, even sophisticated treatments of electron correlation, such as MRCI and XMS-CASPT2 calculations, show oscillator strengths typically lower than experiment. Inclusion of a simple pseudo-diabatization approach to perturb the S1 state with approximate vibronic coupling to the S2 state for each molecule results in more accurate oscillator strengths. Their absolute values agree better with experiment for all molecules except aniline. When the coupling between the S1 and S2 states is strong at the S0 geometry, the simple diabatization scheme performs less well with respect to the oscillator strengths relative to the adiabatic values. However, we expect the scheme to be useful in many cases where the coupling is weak to moderate (where the maximum component of the coupling has a magnitude less than 1.5 au). Such calculations give an insight into the effects of vibronic coupling of excited states on UV/vis spectra.

A palladium pre-catalyst, [Pd(PCy3)2] is reported for the efficient and selective C–F alumination of fluorobenzenes with the aluminium(i) reagent [{(ArNCMe)2CH}Al] (1, Ar = 2,6-di-iso-propylphenyl). The catalytic protocol results in the transformation of sp2 C–F bonds to sp2 C–Al bonds and provides a route to reactive organoaluminium complexes (2a–h) from fluorocarbons. The catalyst is highly active. Reactions proceed within 5 minutes at 25 °C (and at appreciable rates at even −50 °C) and the scope includes low-fluorine-content substrates such as fluorobenzene, difluorobenzenes and trifluorobenzenes. The reaction proceeds with complete chemoselectivity (C–F vs. C–H) and high regioselectivities (>90% for C–F bonds adjacent to the most acidic C–H sites). The heterometallic complex [Pd(PCy3)(1)2] was shown to be catalytically competent. Catalytic C–F alumination proceeds with a KIE of 1.1–1.3. DFT calculations have been used to model potential mechanisms for C–F bond activation. These calculations suggest that two competing mechanisms may be in operation. Pathway 1 involves a ligand-assisted oxidative addition to [Pd(1)2] and leads directly to the product. Pathway 2 involves a stepwise C–H → C–F functionalisation mechanism in which the C–H bond is broken and reformed along the reaction coordinate, guiding the catalyst to an adjacent C–F site. This second mechanism explains the experimentally observed regioselectivity. Experimental support for this C–H activation playing a key role in C–F alumination was obtained by employing [{(MesNCMe)2CH}AlH2] (3, Mes = 2,4,6-tri-methylphenyl) as a reagent in place of 1. In this instance, the kinetic C–H alumination intermediate could be isolated. Under catalytic conditions this intermediate converts to the thermodynamic C–F alumination product., A palladium pre-catalyst, [Pd(PCy3)2] is reported for the efficient and selective C–F alumination of fluorobenzenes with the aluminium(i) reagent [{(ArNCMe)2CH}Al] (Ar = 2,6-di-iso-propylphenyl).

Friedel–Crafts acyl rearrangements in PPA (at 80–240 °C) and Scholl reactions in AlCl3/NaCl (at 140–220 °C) of benzoylnaphthalenes and fluorobenzoylnaphthalenes have been studied experimentally as a function of temperature and time and computationally. 1BzNA, 2BzNA, 1-4FBzNA, 2-4FBzNA, 1-3FBzNA, 2-3FBzNA, 1-2FBzNA, and 2-2FBzNA were synthesized by classical Friedel–Crafts acylations of naphthalene with benzoyl chloride, benzene with 2-naphthoyl chloride, fluorobenzene with 1- and 2-naphthoyl chlorides and of naphthalene with fluorobenzoyl chlorides, and served as substrates in the investigation. Their structures have been determined by X-ray crystallography and verified by their 1H-, 13C-, and 19F-NMR spectra. 1BzNA, 1-4FBzNA, 1-3FBzNA, and 2-2FBzNA crystallized as the E-diastereomers, whereas 2BzAN, 1-2FBzAN, 2-4FBzAN, and 2-3FBzAN crystallized as the Z-diastereomers. The deviations of the carbonyl group from the naphthyl plane were higher as compared with the deviations from the phenyl plane and were considerably higher in the α-naphthyl ketones than in the β-naphthyl ketones. Intermolecular interactions due to C–H···O and/or C–H···F contacts in the crystal structures of 1E-4FBzNA and 1E1′E-3FBzAN have been revealed. 1BzNA rearranged in PPA under argon to 2BzNA via deacylation to naphthalene (e.g., 140 °C, 10 h) and underwent a regioselective intramolecular cyclodehydrogenation at high temperatures to the Scholl reaction product 7H-benz[de]anthracen-7-one (BdeAN) (e.g., 200 °C, 6 h). At 80 °C, benzene was isolated. 2BzNA underwent in PPA deacylation to naphthalene (e.g., 160 °C, 6 h) and an intramolecular cyclodehydrogenation to BdeAN at high temperatures (e.g., 220 °C, 6 h), necessarily via the putative intermediate 1BzNA. Higher yields of the acyl rearrangement and the Scholl reaction products were obtained under oxygen. 1-4FBzNA and 2-4FBzNA reacted in PPA analogously to 1BzNA and 2BzNA, respectively, with the following exceptions: 2-4FBzNA underwent an acyl rearrangement in PPA to 1-4FBzNA at 260–300 °C, without any formation of the Scholl reaction product 10FBdeAN. 1-4FBzNA also did not yield 10FBdeAN. 1-2FBzNA and 2-2FBzNA behaved similarly. The formation of naphthalene and benzene in the deacylation steps indicated cleavages of both the 1- and 2-naphthyl–benzoyl bonds and the 1- and 2-naphthoyl–phenyl bonds to give naphthalene and benzoylium cation and benzene and 1- and 2-naphthoylium cation, respectively. At 80–100 °C, 1-2FBzNA, 1-3FBzNA, and 1-4FBzNA underwent deacylations to fluorobenzene in PPA, followed by reacylation, each giving a mixture of the three 1-fluorobenzoylnaphthalenes. 2FBzNA, 2-3FBzNA, and 2-4FBzNA behaved similarly, each giving a mixture of the three 2-fluorobenzoylnaphthalenes. The results taken together verified the reversibility of the 1-BzNA⇌2BzNA acyl rearrangements in PPA. The Scholl reaction (AlCl3/NaCl) of 1BzNA (e.g., at 140 °C) gave BdeAN and 2BzNA, whereas 2BzNA gave only BdeAN (at 200–220 °C). 1-4FBzNA and 2-4FBzNA gave (at 200–220 °C) only 2-4FBzNA and 1-4FBzNA, respectively. All the six FBzNA isomers failed to undergo Scholl reaction cyclodehydrogenations to give any FBdeAN isomer. A linkage between the Friedel–Crafts acyl rearrangements and the Scholl reaction has thus been established. A systematic DFT study at B3LYP/6-311(d,p)/PCM (formic acid)) substantiated the predicted mechanism and the reversibility of the acyl rearrangements of benzoylnaphthalenes, in which 1BzNA and 2BzNA are the kinetically controlled and the thermodynamically controlled products, respectively. The DFT-calculated Gibbs free-energy of the transition-state (1Z-1BzNH+ ➔➔ 2σ-2BzNA) in the Friedel–Crafts acyl rearrangement of 1Z-BzNA is considerably lower than the transition state of the cyclization step in the arenium-cation mechanism of the Scholl reaction, in line with experiment, which indicated higher temperatures for the Scholl reaction. DFT calculations of the dication pathway of the Scholl reaction of the E- and Z-diastereomers/conformers of 1BzNA confirmed the preference of the formation of BdeAN versus BaFL, consistently with experiment.

We have taken advantage of the high resolution and sensitivity of an 8–18 GHz waveguide FTMW spectrometer in order to measure over 150 new rotational transitions in the ground state of fluorobenzene. Most of these transitions are for previously not covered selection rules and their quantum number coverage allowed the knowledge of the previous quartic-level Hamiltonian for this molecule to be extended to the complete set of sextic centrifugal distortion constants. Experimental results were confronted with anharmonic quantum chemistry calculations allowing the conclusion that for this relatively rigid molecule computation reproduces experiment in the robust way already taken for granted for quartic centrifugal distortion. A similar finding was possible for the ground state of phenylacetylene, although in that case new measurements were required to determine only one hitherto missing sextic constant.

By the example of 4-fluorobenzene-1-thiolate (p-FTP) films on Au(111), we show that a long-term post-preparation storage can improve significantly the quality of fluorinated aromatic self-assembled...

The monitoring of Na+ ions distributed in the body has been indirectly calculated by the detection of Na+ ions in urine. We fabricated a two–dimensional (2D) Na+ ion sensor using a graphene ion–sensitive field–effect transistor (G–ISFET) and used fluorinated graphene as a reference electrode (FG–RE). We integrated G–ISFET and FG on a printed circuit board (PCB) designed in the form of a secure digital (SD) card to fabricate a disposable Na+ ion sensor. The sensitivity of the PCB tip to Na+ ions was determined to be −55.4 mV/dec. The sensor exhibited good linearity despite the presence of interfering ions in the buffer solution. We expanded the evaluation of the PCB tip to real human patient urine samples. The PCB tip exhibited a sensitivity of −0.36 mV/mM and linearly detected Na+ ions in human patient urine without any dilution process. We expect that G–ISFET with FG–RE can be used to realize a disposable Na+ ion sensor by serving as an alternative to Ag/AgCl reference electrodes.

Angewandte Chemie / International edition 60(49), 25674 - 25679 (2021). doi:10.1002/anie.202108242, Proton transfer via tunneling is a fundamental quantum-mechanical phenomenon. We report rotational spectroscopy measurements of this process in the complex of the formic acid dimer with fluorobenzene. The assignment of the spectrum indicates that this complex exists in the form of a $π–π$ stacked structure. Each rotational transition of the parent isotopologue exhibits splitting. Isotopic substitution experiments show that the spectral splitting results from double-proton transfer tunneling in the formic acid dimer. Presence of fluorobenzene as a neighboring molecule does not quench the double proton transfer in the formic acid dimer but decreases its tunneling splitting from 341(3) MHz to 267.608(1) MHz. Calculations suggest that the presence of the weakly bounded fluorobenzene does not influence the activation energy of the proton transfer. The fluorobenzene is reoriented with respect to the formic acid dimer during the course of the reaction, slowing down the proton transfer motion., Published by Wiley-VCH, Weinheim

Rationale Some polycyclic aromatic hydrocarbons (PAHs) are considered to be cancer-causing chemicals, and ion mobility spectrometry (IMS) is used for on-site detection of such hazardous chemicals. In IMS, the ionization behavior of analytes is affected by the types of reactant ions (RIs). In the present work, the influence of different types of RIs on the ionization behaviors of PAHs in an ion mobility spectrometer equipped with a corona discharge ionization source was investigated using various RIs. Methods Selected PAHs were dissolved in anisole, fluorobenzene, chlorobenzene, or bromobenzene. The IMS analysis procedure was performed as follows: (a) the PAH solution was dropped onto the smear matrix; (b) the smear matrix was immediately inserted into the sample inlet to minimize evaporation of the solvent; and (c) the IMS analysis was performed. The lowest amount studied was 10 ng. Variations in the IMS spectra with time were investigated. Results PAHs were not ionized by RIs of protonated molecules ([M + H]+ ) such as air/moisture and acetone, but they were ionized by charge transfer reactions with RIs of molecular ions (M•+ ) of solvents such as anisole, fluorobenzene, chlorobenzene, and bromobenzene. The PAH ions were detected following a time delay of ~1-5 s after the sample introduction, and the times at which the maximum intensities for the PAHs were observed were different. The detection limits of PAHs in chlorobenzene were on the whole better than those in other solvents, whereas those in fluorobenzene were worse. The detection limits of pyrene and benzo[a]anthracene were better than those of the other PAHs irrespective of the solvent used. Conclusions PAH molecules were ionized by charge transfer reactions with RIs of the solvents, and their ions were detected ~1-5 s after sample introduction. The order of the ionization efficiency was chlorobenzene > anisole > bromobenzene > fluorobenzene.

A homogeneous rhodium–indium catalyst hydrodefluorinates substrates bearing strong aryl C–F bonds, including difluoro- and fluorobenzene, using 1 atm of H2, alkoxide bases, and moderate temperature...

Chemical analysis via nuclear magnetic resonance (NMR) spectroscopy using permanent magnets, rather than superconducting magnets, is a rapidly developing field. Performing the NMR measurement in the strong heteronuclear J-coupling regime has shown considerable promise for the chemical analysis of small molecules. Typically, the condition for the strong heteronuclear J-coupling regime is satisfied at &micro, T magnetic field strengths and enables high resolution J-coupled spectra (JCS) to be acquired. However, the JCS response to systematic chemical structural changes has largely not been investigated. In this report, we investigate the JCS of C6H6&minus, xFx (x = 0, 1, 2, &hellip, 6) fluorobenzene compounds via simultaneous excitation and detection of 19F and 1H at 51.5 &micro, T. The results demonstrate that JCS are quantitative, and the common NMR observables, including Larmor frequency, heteronuclear and homonuclear J-couplings, relative signs of the J-coupling, chemical shift, and relaxation, are all measurable and are differentiable between molecules at low magnetic fields. The results, corroborated by ab initio calculations, provide new insights into the impact of chemical structure and their corresponding spin systems on JCS. In several instances, the JCS provided more chemical information than traditional high field NMR, demonstrating that JCS can be used for robust chemical analysis.

The binding of a positron to fluorobenzene molecules was theoretically demonstrated at Hartree-Fock level of multi-component molecular orbital theory. We confirmed that (i) 1,2-difluorobenzene, 1,2,3-trifluorobenzene, 1,2,3,4-tetrafluorobenzene molecules have bound states for a positron, and (ii) their positron affinity (PA) and two photon pair-annihilation rate (Γ2) are strongly correlated with their dipole moment. Analyzing the Γ2 values for each electronic molecular orbital in all the fluorobenzene molecules, we found that the electronic valence orbitals, consisting of 2p atomic orbitals of fluorine atoms, have the dominant contribution to the total Γ2 value.

The isolation and solid-state characterisation of complexes featuring partially coordinated benzene, fluorobenzene and all three isomers of difluorobenzene are described. Supported by a DFT analysis, this well-defined homologous series demonstrates the preference for η2-coordination of fluoroarenes via the HC[double bond, length as m-dash]CH sites adjacent to a fluorine substituent.\ud \ud

Finding suitable aqueous additives to inhibit the mass transfer of water molecules in double emulsion droplets is beneficial for improving the surface quality of polymer shells. In this work, fluorobenzene/aqueous systems with polyvinyl alcohol (PVA) molecules and electrolyte ions were constructed by molecular dynamics simulation, which are typical water/oil (W/O) systems in actual fabrication processes of polymer shells. The interfacial mass transfer coefficients and equilibrium water solubility in fluorobenzene of various W/O systems were calculated by fitting the dissolution curves with a classical mass transfer model. The effects of polyvinyl alcohol additives on the diffusion process of water molecules at the fluorobenzene/water interface were investigated from the perspectives of thermodynamics and microscopic interface morphology. Furthermore, to avoid the inner surface defects of polymer shells caused by electrolyte ions osmosis, 1,3-butanediol molecules were proposed to replace ions as aqueous solutes, which also inhibited the diffusion of water molecules to fluorobenzene membrane.

Antidepressants paroxetine and sertraline both as their hydrochlorides were studied regarding thermal behavior by TG/DTG-DTA, DSC, hot-stage microscopy, X-ray diffraction and coupled TG-FTIR. Paroxetine presented a single mass loss step after dehydration, in nitrogen. However, DTA curve revealed that such degradation actually occurs in three steps, in which HCl, piperidine, fluorobenzene and CO2 are released. In air decomposition took place in a similar way. DSC showed endothermic peaks related to melting and dehydration of paroxetine. During evolved gases analysis it was possible to observe overlapped signals related to HCl and piperidine absorption. Sertraline, on its turn, presented sublimation when slowly heated or alternatively a solid transition from Form II to Form III at c.a. 199 °C followed by two mass losses when heated at higher heating rates. In the first degradation step methylamine is released. The second step is related to the loss of tetraline, dichlorobenzene and HCl, as revealed by TG-FTIR. Based on these data, thermal decomposition mechanisms were proposed for both drugs.

4′-Alkyl-4-alkoxy-3-fluorobiphenyls and laterally mono-, two- and three-fluorosubstituted 4″-alkyl-4-fluoroterphenyls were synthesized and used as the components of mixtures with a broad temperature range of the monolayer smectic A phase and the Cr-SmA1-Iso or Cr-SmA1-N-Iso phase sequence. Several ionic potassium complexes of 18-crown-6-ether and dibenzo-18-crown-6-ether with different anions (Br−, ClO4−, 4-octylphenolate, 3,4-difluorophenolate, 3,5-difluoro-4-cyanophenolate and 4-dodecylbenzenesulfonate) were prepared and their solubility and conductivity in fluorobenzene were measured. Properties of dynamic scattering and clear states (threshold and saturation voltages) of two types of mixtures (mixture A with Cr-SmA1-Iso and mixture B with Cr-SmA1-N-Iso phase sequences) doped with above mentioned ionic compounds have been tested. The mixture B has the smectic layers more defected and it shows excellent properties to design displays with memory or smart windows.

In this work, two wide-bandgap polymers PBDTBT-1FB and PBDTBT-2FB were designed and synthesized with fluorobenzene (1FB) and difluorobenzene (2FB), respectively, which were inserted between the benzodithiophene (BDT) and benzothiadiazole units (BT) in polymer backbone. Functionalization of the phenylene unit with fluorine atom has a significantly effect on the energy levels and charge transportation properties of the polymers. Both PBDTBT-1FB and PBDTBT-2FB exhibited wide-bandgaps of ∼1.98 eV with deeper-lying HOMO levels. PBDTBT-2FB containing 2FB showed better hole transportation abilities than PBDTBT-1FB due to its good film quality. As a result, polymer PBDTBT-1FB containing 1FB has reached power conversion efficiency (PCE) of 2.16%, with open circuit voltage (Voc) of 0.95 V in optimized devices. The photovoltaic performance of PBDTBT-2FB was improved by increasing its Voc up to 1.0 V, resulting in a PCE of 3.34%. The wide-bandgap polymers containing fluorinated phenylene units result in the simultaneous promotion of Voc.

Infinite dilution activity coefficients were measured for 32 liquid organic solutes dissolved in pentyl acetate at 298.15 K. The organic solutes included both saturated (hexane through decane, cyclohexane) and unsaturated hydrocarbons (1-hexene, 1-heptene, cyclohexene, 1-octyne, 1,7-octadiene), several substituted benzene derivatives (benzene, methylbenzene, ethylbenzene, propylbenzene, 1,3-dimethylbenzene, 1-dimethylbenzene, fluorobenzene, bromobenzene), four haloalkanes (trichloromethane, 1-chlorobutane, 1,2-dichloropropane, isopropyl bromide) and three alcohols (ethanol, 1-propanol, 2-propanol), as well six miscellaneous organic compounds (acetonitrile, ethyl acetate, tetrahydrofuran, 1,4-dioxane, propanone, nitromethane). Mole fraction solubilities were also determined for 10 crystalline nonelectrolyte organic solutes dissolved in pentyl acetate. Results of the experimental measurements were used to derive Abraham model correlations for describing thermodynamic properties of solute transfer into pentyl acetate. The derived Abraham model correlations mathematically described the observed data to within 0.12 log units (or less).

Reaction of Me3Al with HB[N(H)DIPP](2) (DIPP = 2,6-iPr(2)-C6H3) in hexane gave a complex mixture of compounds instead of HB(N-DIPP)(2)AlMe. After addition of THF, one of the products could be trapped in trace amounts and was characterized by crystal structure determination: DIPP-N(H)B(H)(N-DIPP)AlMe2 center dot THF (1). Heating a hexane or fluorobenzene solution of HB[N(H)DIPP](2) and Me3Al in the absence of THF gave a relatively clean conversion and allowed for the isolation of [(DIPPNH)AlMe2(mu-H)AlMe2](2) (2), a product that was formed through B/Al ligand exchange. Complex 2 contains protic and hydridic hydrogen atoms in close vicinity. The compound remains intact upon heating, however, it readily releases H-2 when dissolved in THF forming DIPPN(AlMe2 center dot THF)(2) (3). The latter bimetallic complex contains two THF stabilized Lewis acidic central aluminum atoms in close proximity.

The long-range scalar coupling constant between proton and fluorine nuclei, 5 JHF , is observed to be larger than 3 JHF in the pyrimidinyl moiety of voriconazole. A set of smaller molecules is chosen (fluorobenzene, N-methyl-2-fluoropyridine, N-methyl-3-fluoropyridine, 3-fluoropyridine, 5-pyrimidine, and 2-fluoropyridine) to evaluate the influence of the nitrogen atom in the experimental JHF values. Spectral aliased pure shift heteronuclear single quantum coherence spectroscopy (SAPS-HSQC) is applied to determine the relative sign between the JCF and JHF scalar couplings. Theoretical calculations show that the 3 JHF and 5 JHF coupling constants can be described mainly by a Fermi contact (FC) transmission mechanism. A decomposition analysis of JHF in terms of localized molecular orbital (LMO) contributions allows us to determine that the interaction involving the nitrogen lone pair (LPN) is the main reason for the larger 5 JHF compared to 3 JHF . Our analysis indicates that delocalization of LPN has a positive contribution to the long-range coupling, while a negative one is observed for 3 JHF .

Citalopram, [(R,S)-1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydroisobenzofuran-5-carbonitrile] hydrobromide and its S-isomer, escitalopram oxalate, were analyzed regarding thermal degradation by TG/DTG–DTA, DSC, hot-stage microscopy and coupled TG-FTIR techniques. Citalopram presented a decomposition in a single step after melting at 189.3 °C (ΔHfus= 94.4 J g−1), without evidences of crystallization on cooling. Thermal techniques results combined with those from evolved gas analysis suggested decomposition via HBr, dimethylamine and fluorobenzene. Escitalopram presented a thermal degradation that started with the decomposition of the counter ion, after melting at 158.3 °C (ΔHfus= 106.2 J g−1), without evidences of crystallization on cooling followed by the release of dimethylamine and fluorobenzene. GC–MS of the residues confirmed the observations from the thermal analysis, but revealed several intermediates in the degradation of the racemate, probably due to the mixture of isomers. Differences in thermal behavior were attributed to differences in structure and counter ions. A tentative mechanism for their thermal behavior is proposed in both cases.

Two molecular rotors featuring pyridine and fluorobenzene rings as polar rotators and 9-octylfluorenyl stators were synthesized. Their crystal structures were established through SXRD techniques, crystallizing in the monoclinic chiral P21 space group. The supramolecular assemblies of both isomorphs showed an orientation of static dipoles through the crystal lattice and the formation of intriguing 2D layers that resemble cell membranes, a typical example of an amphidynamic system. Small activation energies and the modulation of the first-order hyperpolarizabilities of these compounds as a function of rotational dynamics were revealed through DFT computations at the CAM-B3LYP/M06-2X/cc-pVDZ level of theory and correlated with a potential use of these materials as photonic switches.

Volumetric, viscometric and speed of sound studies of binary mixtures of tert-butyl acetate with fluorobenzene, chlorobenzene and bromobenzene have been made over the entire range of composition, at (298.15 and 308.15) K and at atmospheric pressure (p = 0.089 MPa). From the experimental values of density, viscosity, and speed of sound, the excess molar volumes VE, deviations in viscosity ∆η and deviation in isentropic compressibility ΔK S have been calculated. The VE and ΔK S values are negative while the ∆η the values are positive over the entire composition range for the binary mixtures. The derived parameters have been fitted with the Redlich–Kister polynomial equation. The interaction parameters of McAllister model are used to correlate the experimental values of density, viscosity and speed of sound.

Quinoxaline (Qx) has an easily modifiable structure, which allows for fine-tuning its properties through optimizing the length of side chains and the kinds of aromatic rings in conjugated side chains. Qx based polymer PBDTT-ffQx with alkoxy substituted fluorobenzene side chains shows a power conversion efficiency (PCE) of 8.47% in nonfullerene solar cells. In this work, we change the alkoxy substituted fluorobenzene side chains to alkyl substituted fluorothiophene in the Qx unit and employ the benzodithiophene (BDT) unit with different lengths of alkyl thiophene side chains to obtain two new Qx based polymers, named TTFQx-T1 and TTFQx-T2, respectively. The TTFQx-T1:ITIC blend film has clear nanoscale phase separation and a suitable domain size, and the device with the TTFQx-T1:ITIC blend film shows lower geminate recombination and higher charge mobility than those with TTFQx-T2:ITIC. Therefore, the TTFQx-T1:ITIC based device exhibits a higher PCE of 10.52% than that based on the TTFQx-T2:ITIC blend with a moderate PCE of 7.22%. The inverted devices from TTFQx-T1:ITIC blends with a larger active area of 16 mm2 than the conventional device (4.5 mm2) show a good PCE of 9.21%. The results highlight that the alkyl lengths and the kinds of aromatic rings in side chains are significant for the development of high performance photovoltaic polymers. Optimizing the conjugated side chains of Qx based polymers is an efficient way to improve photovoltaic properties, and Qx based polymers are potential candidates for fabricating highly efficient polymer solar cells.

Herein, a novel carbazole derivative ((E)-2-(1-(9-butyl-9H-carbazol-3-yl)-3-(4-fluoro-phenyl)allylidene)malononitrile (3)) containing multi-cyano group and 4-fluoro-benzene unit was synthesized. This compound displayed aggregation-induced emission properties owing to the highly twisted conformation. It exhibited multi solid-state fluorescence emissions (yellow (3Y) and orange (3O)) and two crystalline polymorphs. Through single crystal structural analysis, we observed compound 3 with different conformations and variable molecular packing modes, which resulted in different solid-state fluorescence emissions, polymorphism, mechanochromic behaviors and unique non-reversible thermo-stimulus fluorescence. The fluorescence emission of the yellow solid displayed distinct red-shift after grinding, which is attributed to the breakup of the crystal structure, while that of the orange solid was not evident due to its stable and ordered molecular packing. Additionally, the yellow solid (3Y) also exhibited thermo-stimulus fluorescence, turning into 3O, and crystal phase transition. The lower energy and the compact packing modes of 3O should be collectively responsible for the unique behavior.

A novel highly selective Ag-catalyzed intermolecular amination of fluoroarenes has been developed. This transformation starts from readily available 4-carbonyl fluorobenzene and NaN3 or other nitrogen-source, via amination followed by C-F bond cleavage, thus affording the desired 4-carbonyl arylamine products under mild conditions. The reaction is accelerated using a small amount of water. This pathway is distinct from a previously reported radical amination reaction.

There are studies which indicate that some fluorobenzene derivatives have inotropic activity; nevertheless, the cellular site and mechanism of action at cardiovascular level is very confusing. To clarify these phenomena in this study, a new fluorobenzene derivative was synthesized to evaluate its biological activity on perfusion pressure and left ventricular pressure. The Langendorff technique was used to measure changes on perfusion pressure and coronary resistance in an isolated rat heart model in absence or presence of the fluorobenzene derivative [0.001 nM]. Additionally, to characterize the molecular mechanism involved in the inotropic activity induced by the fluorobenzene derivative was evaluated by measuring left ventricular pressure in absence or presence of following compounds; ouabain, digoxin, levosimendan, cyclopiazonic acid and thapsigargin. The results showed that the fluorobenzene derivative significantly increased the perfusion pressure and coronary resistance in comparison with the control conditions. Additionally, other data indicate that fluorobenzene derivative increase perfusion pressure in a form similar to ouabain and digoxin; however, this effect was different compared with levosimendan. Other results showed that biological activity induced by the fluorobenzene on left ventricular pressure was significantly inhibited by both cyclopiazonic acid [50 mM] and thapsigargin [300 mM]. These data suggest that positive inotropic activity induced by the fluorobenzene on perfusion pressure and left ventricular pressure was via changes of biological activity both Na,K-ATPase and Ca+2-ATPase. This phenomenon is a particularly interesting because the positive inotropic activity induced by this fluorobenzene derivative involves a molecular mechanism different in comparison with other positive inotropic drugs.

Two novel radiotracers, namely, N-(4-[18F]fluorobenzyl)-N-methyl-2-(7-methyl-8-oxo-2-phenyl-7,8-dihydro-9H-purin-9-yl)acetamide ([18F]5) and 2-(5-(4-[18F]fluorophenyl)-2-oxobenzo[d]oxazol-3(2H)-yl)-N-methyl-N-phenylacetamide ([18F]6), were developed for positron emission tomography (PET) imaging of translocator protein (18 kDa) (TSPO) in ischemic brain in this study. The two radiotracers with a [18F]fluorobenzene ring were derived from the corresponding [18F]fluoroethyl tracers [18F]7 and [18F]8 which underwent [18F]defluoroethylation in vivo easily. [18F]5 or [18F]6 was synthesized by the radiofluorination of the spirocyclic iodonium ylide precursor 10 or 17 with [18F]F− in 23 ± 10% (n = 7) or 56 ± 9% (n = 7) radiochemical yields (decay-corrected, based on [18F]F−). [18F]5 and [18F]6 showed high in vitro binding affinities (Ki = 0.70 nM and 5.9 nM) for TSPO and moderate lipophilicities (log D = 2.9 and 3.4). Low uptake of radioactivity for both radiotracers was observed in mouse bones. Metabolite analysis showed that the in vivo stability of [18F]5 and [18F]6 was improved in comparison to the parent radiotracers [18F]7 and [18F]8. In particular, no radiolabelled metabolite of [18F]5 was found in the mouse brains at 60 min after the radiotracer injection. PET studies with [18F]5 on ischemic rat brains revealed a higher binding potential (BPND = 3.42) and maximum uptake ratio (4.49) between the ipsilateral and contralateral sides. Thus, [18F]5 was shown to be a useful PET radiotracer for visualizing TSPO in neuroinflammation models.

We report a highly diastereo- and enantioselective synthesis of cyclopropanes with adjacent all-carbon quaternary stereocenters featuring a monofluoromethyl (CH2F) group. While the spiroketal bisphosphine (SKP) derived chiral digold complex was identified to be a powerful catalyst for the cyclopropanation of unprotected diazooxindoles with α-CH2F styrenes, Rh2(R-DOSP)4 proved to be excellent in the corresponding reactions using aryl diazoacetate. In the cyclopropanation of diazooxindoles, dramatic rate acceleration (about twenty times) was observed when varying the reaction solvent from chlorobenzene (PhCl) to fluorobenzene (PhF), which cannot be explained by two factors that are widely used to explain the solvent effects on the olefin cyclopropanation (the dielectric constant and the coordinating ability of the solvent). Theoretical calculations suggest the formation of strong C–F⋯H–N interaction between PhF and the N–H bond of the unprotected diazooxindole derived Au(I)-carbenoid intermediate, which effectively lowers the reaction barrier. This result first demonstrated that it is possible to harness the C–F⋯H–X interaction between fluorinated solvents and the reactive intermediates to tune both the reactivity and stereoselectivity of a catalytic asymmetric reaction.

We investigate single photon double ionization (spDI) of substituted benzenes (toluene, chlorobenzene and fluorobenzene) in photon energy of 20–40 eV. We observe that a resonance-like enhancement of spDI, which deviates from the prediction of the “knock-out” mechanism, appears at a specific photon energy near the threshold for halogenated benzenes, but not for toluene. The enhanced spDI occurs if the de Broglie wavelength of the two-electron pseudoparticle matches the size of the conjugated p-π orbital of halogenated benzene. Our study shows that the molecular spDI is not a local event and the molecular orbital plays a pivotal role in double ionization.