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• The obtained monolith revealed satisfactory permeability and mechanical stability. • Fluorobenzenes were successfully separated on the prepared monolith. • Regulating the polarity of monoliths was achieved by host-guest interaction. Hierarchically porous monoliths with satisfactory properties have been employed in diverse fields, especially separation. In this study, pentafluorophenyl acrylate (PFPA), pentaerythritol tetraacrylate (PETA) and trimethylolpropane tris(3-mercaptopropionate) (TTMP) were selected as precursors to fabricate a novel monolithic column by thermally initiated polymerization in the presence of a binary porogenic system containing tetrahydrofuran and 1-propanol. The fabricated poly(PFPA- co -PETA- co -TTMP) monolithic column revealed excellent permeability and mechanical stability. Additionally, baseline separation of the mixture of small molecules can be achieved, involving alkylbenzene and fluorobenzene in chromatographic assessment, and the theoretical plate number is up to 60,500 plates/m for butylbenzene with a linear velocity of 0.14 mm/s. Tryptic digest of HeLa as an analyte was used to investigate the possibility of the poly(PFPA- co -PETA- co -TTMP) monolith in biological separation by cLC-MS/MS. Moreover, benefiting from the existence of pentafluorophenyl groups, the cucurbit[8]uril (CB[8]) could be modified on the prepared poly(PFPA- co -PETA- co -TTMP) monolith through host-guest interaction to obtain poly(PFPA- co -PETA- co -TTMP)-CB[8] monolith. It could be observed that significant changes in retention behavior of analytes appeared after immobilizing CB[8] on the monolith. It offered an innovative approach by utilizing host-guest interaction to fabricate monolithic columns with different chromatographic behaviors. [ABSTRACT FROM AUTHOR]

A kind of anion exchange membranes (AEMs) with C C bond end-group crosslinked structure was synthesized successfully. Unlike the traditional aliphatic AEMs, the AEMs were prepared in this work by a strategy to realize the C C bond thermal end-group crosslinking reaction, exhibiting an obvious microphase separation structure and a suitable dimensional stability. The well-defined ion channels constructed in the AEMs guarantee the fast OH− conduction, as confirmed via physical and chemical characterization. The conductivity was dramatically enhanced due to the effective ion channels and increased ion exchange capacity. Among the as-prepared AEMs, the PHFB-VBC-DQ-80% AEM has a conductivity of 135.80 mS cm−1 at 80 °C. The single cell based on PHFB-VBC-DQ-80% can achieve a power density of 141.7 mW cm−2 at a current density of 260 mA cm−2 at 80 °C. The AEMs show good thermal stability verified by a thermogravimetric analyzer (TGA). Furthermore, the ionic conductivity of PHFB-VBC-DQ-80% only decreased by 7.1% after being soaked in a 2 M NaOH solution at 80 °C for 500 h. [Display omitted] • C C bond was introduced into an AEM to form end-group crosslinked structure. • The AEMs possess an obvious microphase separation structure. • PHFB-VBC-DQ-80% has a conductivity of 135.80 mS cm−1 at 80 °C. • The AEMs with C C crosslinker possess good chemical stability. [ABSTRACT FROM AUTHOR]

• Density and speed of sound of (iodobenzene+ n -alkane) mixtures are measured at t = (288.15 K to 308.15 K) and p = 0.1 MPa. • Excess molar volume (V m E) and isentropic compressibility (κ S E) are calculated and correlated. (∂ V m E / ∂ T) p are also calculated. • The V m E results are compared with those (fluorobenzene, chlorobenzene or bromobenzene + n -alkane) mixtures. • The V m E variation with the n -alkane size is determined by the variation of the contribution from structural effects. • The Prigogine-Flory-Patterson model is applied and supports the conclusions from the analysis of experimental data. (Iodobenzene + n -alkane) liquid mixtures have been studied experimentally, in terms of densities (ρ) and speeds of sound (c), and theoretically, by the application of the Prigogine-Flory-Patterson (PFP) model. The n -alkanes considered are n -heptane, n -decane, n -dodecane, and n -tetradecane. ρ and c measurements have been performed at a pressure p = 0.1 MPa and in the temperature range T = (288.15 to 308.15) K. Excess molar volumes (V m E) and excess isentropic compressibilities (κ S E) have been calculated and correlated by Redlich-Kister polynomials. (∂ V m E / ∂ T) p curves at the same (p , T) conditions have been obtained from correlated V m E values. The mixtures are characterized by the following features: (i) V m E increases with the number of carbon atoms of the n -alkane (n), being negative for n = 7, small and S-shaped with positive and negative values for n = 10, and positive for n = 12 and n = 14; (ii) κ S E and (∂ V m E / ∂ T) p are negative, increase with n and are very close to zero for n = 14. From these experimental results and the knowledge of the excess molar enthalpies of mixtures containing fluorobenzene, chlorobenzene or bromobenzene with n -alkanes, we have inferred the presence of structural effects, especially important for n = 7 and less relevant for volumetric properties as n increases. The V m E obtained are compared with those of other (halogenated benzene + n -alkane) liquid mixtures existing in the literature, namely systems with fluorobenzene, chlorobenzene, and bromobenzene. From this comparison and the analysis of the isobaric thermal expansion coefficients of the pure compounds, it is inferred that the interactional effects on V m E do not vary appreciably with the length of the n -alkane, so the observed V m E variation is fundamentally determined by the corresponding variation of the contribution from structural effects. Moreover, the application of the PFP model supports this interpretation, providing free volume contributions to V m E that vary parallelly to V m E with the length of the n -alkane, and interactional contributions that rest approximately constant independently of the n -alkane size. [ABSTRACT FROM AUTHOR]

Azeotropes are boiling liquid mixtures which have identical vapor and liquid compositions. Known as polyazeotropy, azeotropic mixtures may exhibit more than one azeotrope at a given temperature or pressure. While the thermodynamic condition for azeotrope formation in vapor-liquid equilibrium is well established, thermodynamic modeling of mixtures exhibiting polyazeotropy remains challenging and prior modeling studies often failed to satisfactorily correlate the polyazeotropic behavior of associating systems. Based on the association NRTL model, this study presents successful correlation and analysis of double azeotrope formation for three diverse systems: strongly associating methanol + diethylamine binary, weakly associating ammonia + pentafluoroethane binary, and non-associating benzene + hexafluorobenzene binary systems. These systems exhibit polyazeotropic behavior as the temperature increases and approaches their Bancroft points. [ABSTRACT FROM AUTHOR]

[Display omitted] The direction of the reaction between substituted perfluorobenzenes and thioacetic acid depends on the location of the substituents in perfluoroaromatic ring. Hexafluorobenzene reacts at positions 1 and 4, perfluoro- m -xylene reacts at positions 4 and 6, while perfluoroindane reacts at positions 5 and 6 to give the corresponding dithiols with para -, meta - and ortho -location of the thiol groups, respectively. Domino-reaction of perfluoroindane-5-thiol and its acetyl thioester affords hexadecafluoro-2,12-dithia-pentacyclo[11.7.0.03,11.05,9.015,19]icosa-1(13),3,5(9),10,14,19-hexaene [ABSTRACT FROM AUTHOR]

• 1-Tetrafluorophenyl-perfluoro-1-phenylpropanes were synthesized. • 1-Tetrafluoropheny-l-(pentafluorophenyl)prop-1-yl cations were generated. • Polyfluorinated diphenylpropanes undergo cyclization into polyfluoro-9-ethylfluorenes. • A convenient method for the synthesis of perfluoro-9-ethylfluorene has been developed. The interaction of perfluoropropylbenzene with 1,2,3,4-tetrafluorobenzene or 1,2,4,5-tetrafluorobenzene in an SbF 5 medium at r.t. yields corresponding 1-(tetrafluorophenyl)perfluoro-1-phenylpropanes, which undergo cyclization into perfluoro-9-ethylfluorene or 1,2,3,4,5,7,8,9-octafluoro-9-(pentafluoroethyl)fluorene along with 1,2,3,4-tetrahydro-9 H -fluorenes under the reaction conditions. The reaction of perfluoropropylbenzene with 1,2,3,5-tetrafluorobenzene under the same conditions leads to the formation of 1-(2,3,4,6-tetrafluorophenyl)perfluoro-1-phenylpropane, which does not give cyclization products at 50–55 °C. [Display omitted] [ABSTRACT FROM AUTHOR]

Recently, temporary anion states of fluorine substituted benzenes have been probed via photodetachment experiments on oxygen-fluorobenzene anion complexes [O 2 ⋅ C 6 H 6 − n F n ] − , n = 0 ... 6. Here, we complement these experiments with a computational characterization. For the ground electronic states, two isomers are identified: The first isomer class shows non-conventional hydrogen bonds, while the second shows carbon-oxygen contacts. For both isomer classes, the electron affinity of the complex is significantly higher than that of either moiety, and the electron affinity increase upon complex formation is studied in detail. Both isomer classes show strong O 2 − − C 6 H 6 − n F n interactions, and the extent of charge donation from O 2 − to the organic moiety is characterized. Moreover, we characterize charge-transfer excited states of [O 2 ⋅ C 6 H 6 − n F n ] − anion complexes corresponding to neutral O 2 bound to C 6 H 6 − n F n −. The charge transfer complexes form doublets and quartets, and here we focus on the minimal energy structure of the quartet state and characterize the doublet at the same geometry. [Display omitted] • Photodetachment probes charge-transfer excitations in anion-molecule complexes. • O 2 − and flurorinated benzenes form strongly bound anion-molecule complexes. • Possible binding motifs: non-conventional hydrogen bonds and C O contacts. • Hydrogen bonded complexes show little anion to molecule charge donation. • C O bonded complexes show substantial anion to molecule charge donation. [ABSTRACT FROM AUTHOR]

Abstract Practical preparations of dichloromethyl alkyl ethers are described, based on the reaction of alkyl formates with oxalyl chloride in the presence of N -methylformanilide. The method involves a simple procedure that does not require the use of harmful reagents. Dichloromethyl propyl and dichloromethyl butyl ethers represent secure synthetic equivalents to dichloromethyl methyl ether. Formylations of both electron-deficient and electron-rich aromatics with these dichloromethyl alkyl ethers in the presence of AlCl 3 , FeCl 3 , or TiCl 4 have been systematically investigated. A plausible mechanism of formylation is discussed. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Highlights • Sertraline and paroxetine were submitted to thermal, and hot stage microscopy analysis. • Paroxetine presented concomitant dehydration and melting followed by crystallization. • It decomposed in three mass loss steps releasing HCl, piperidine, fluorobenzene and CO 2. • Sertraline undergoes sublimation or solid transformation depending on the heating rate. • Decomposition occurred in two steps releasing methylamine, tetraline, dichlorobenzene and HCl. Abstract 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 CO 2 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. [ABSTRACT FROM AUTHOR]

Three π-conjugated small molecules (SMs) with D(π-A-Ar) 2 molecular frameworks are designed and synthesized as the donor materials in organic solar cells (OSCs). Containing tetrafluorobenzene (TFB) as central donor (D) core, thiophene as π-bridge, 2-octylthiophene (T) as terminal (Ar) unit, as well as the different arm of acceptor (A) units, pyridine-diketopyrrolopyrrole (PyDPP), thiophene-diketopyrrolopyrrole (TDPP) and isoindigo (IID), namely DTTFB(PyDPP-T) 2 , DTTFB(TDPP-T) 2 and DTTFB(IID-T) 2 , respectively. The impacts of the different acceptor arms combined with the TFB core on the optical absorption, electrochemical property, hole mobility, film morphology, and solar cell performance were studied thoroughly. As a result, these SMs presented various light absorption properties, electrochemical performances, and hole mobilities, which are helpful to the optimization of short-circuit current ( J sc ), open-circuit voltage ( V oc ) and fill factor (FF) properties, respectively. Especially, the DTTFB(TDPP-T) 2 showed a relatively lower optical band gap of 1.53 eV, and also showed the best coplanarity among the three SMs, which help it to get a higher J sc of 12.44 mA cm −2 and a higher FF of 59.50%, and resulting in obtaining a best power conversion efficiency (PCE) of 5.15% in the DTTFB(TDPP-T) 2 /PC 71 BM-based cells, which is about 2.8 and 1.6 times higher than that of DTTFB(PyDPP-T) 2 /PC 71 BM and DTTFB(IID-T) 2 /PC 71 BM based cells, respectively. Obviously, introducing different acceptor units as arms onto the D(π-A-Ar) type SMs could be a promising strategy for designing high-performance TFB-based linear molecular donor materials. [ABSTRACT FROM AUTHOR]

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 ( V oc ) of 0.95 V in optimized devices. The photovoltaic performance of PBDTBT-2FB was improved by increasing its V oc 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 V oc . [ABSTRACT FROM AUTHOR]

Electrochromic devices based on high-performance polymer materials with exceptional optical contrast, superior cycling stability, and large coloration efficiency are critical for the advancement of electrochromics, and have the potential to innovate a broad range of applications, including flexible displays and wearable electronics. Here, we design and synthesize three precursors of fluorobenzene-3-methylthiophene D-A-D type polymers through one-step Stille coupling, and then prepare the corresponding polymer films with good electrochemical and electrochromic properties via low-potential electropolymerization at 0.52 V vs Ag/AgCl. Interestingly, such polymers exhibit overall high electrochromic performances during the electrochemical reaction with inversible color changes between yellow and dark blue, including high optical contrast (83% at 1050 nm), fast response time (1.4 s / 0.8 s), and long-term stability (< 2% reduction after 250 cycles). As-fabricated electrochromic devices display excellent cycling stability (< 3% optical contrast degradation after 1,000 cycles) at a low drive voltage (0.8 V). Due to these excellent electrochromic properties, d -A-D type polymers based on fluorobenzene-3-methylthiophene can be further developed for practical applications such as near-infrared camouflage and E-displays. [Display omitted] [ABSTRACT FROM AUTHOR]

Introduction Enterohepatic circulation (EHC) of conjugated bile acids is an important physiological process crucial for regulation of intracellular concentrations of bile acids and their function as detergents and signal carriers. Only few bile acid-derived imaging agents have been synthesized and hitherto none have been evaluated for studies of EHC. We hypothesized that N -(4-[ 18 F]fluorobenzyl)cholylglycine ([ 18 F]FBCGly), a novel fluorine-18 labeled derivative of endogenous cholylglycine, would be a suitable tracer for PET of the EHC of conjugated bile acids, and we report here a radiosynthesis of [ 18 F]FBCGly and a proof-of-concept study by PET/MR in rats. Methods A radiosynthesis of [ 18 F]FBCGly was developed based on reductive alkylation of glycine with 4-[ 18 F]fluorobenzaldehyde followed by coupling to cholic acid. [ 18 F]FBCGly was investigated in vivo by dynamic PET/MR in anesthetized rats; untreated or treated with cholyltaurine or rifampicin. Possible in vivo metabolites of [ 18 F]FBCGly were investigated by analysis of blood and bile samples, and the stability of [ 18 F]FBCGly towards enzymatic de-conjugation by Cholylglycine Hydrolase was tested in vitro . Results [ 18 F]FBCGly was produced with a radiochemical purity of 96% ± 1% and a non-decay corrected radiochemical yield of 1.0% ± 0.3% (mean ± SD; n  = 12). PET/MR studies showed that i.v.-administrated [ 18 F]FBCGly underwent EHC within 40–60 min with a rapid transhepatic transport from blood to bile. In untreated rats, the radioactivity concentration of [ 18 F]FBCGly was approximately 15 times higher in bile than in liver tissue. Cholyltaurine and rifampicin inhibited the biliary secretion of [ 18 F]FBCGly. No fluorine-18 metabolites of [ 18 F]FBCGly were observed. Conclusion We have developed a radiosynthesis of a novel fluorine-18 labeled bile acid derivative, [ 18 F]FBCGly, and shown by PET/MR that [ 18 F]FBCGly undergoes continuous EHC in rats without metabolizing. This novel tracer may prove useful in PET studies on the effect of drugs or diseases on the EHC of conjugated bile acids. [ABSTRACT FROM AUTHOR]

Structural transformations of 3-fluorobenzaldehyde (C 7 H 5 FO; 3FBA) and 3-fluoro-4-methoxybenzaldehyde (C 8 H 7 FO 2 ; 3F4MBA), taking place in different solid phase environments and at low temperature, were investigated by infrared spectroscopy, complemented by quantum chemistry calculations undertaken at the DFT(B3LYP)/6–311++G(d,p) level of approximation. The studied compounds were isolated from gas phase into cryogenic inert matrices (Ar, Xe), allowing to characterize their equilibrium conformational composition in gas-phase at room temperature. In both cases, two conformers differing by the orientation of the aldehyde moiety (with the carbonyl aldehyde bond cis or trans in relation to the aromatic ring fluorine substituent) were found to coexist, with the cis conformer being slightly more populated than the trans form. In situ narrowband UV irradiation of the as-deposited matrices led either to preferential isomerization of the cis conformer into the trans form or decarbonylation of both conformers, depending on the used excitation wavelength. Deposition of the vapours of 3F4MBA only, onto the cold (15 K) substrate, produced an amorphous solid containing also both the cis and trans conformers of the compound. Subsequent heating of the amorphous phase up to 268 K led to crystallization of the compound, which is accompanied by conformational selection, the cis form being the single species present in the crystal. The experimentally observed transformations of the studied compounds, together with the structural and vibrational results obtained from the performed quantum chemical calculations, allowed a detailed structural and vibrational characterization of the individual conformers. [ABSTRACT FROM AUTHOR]

A reliable protocol for converting 1,4-diiodo-2,3,5,6-tetrafluorobenzene into 1-(hetero)aryl-4-iodo-2,3,5,6-tetrafluorobenzene derivatives has been lacking in the literature. We have identified optimal conditions to achieve this conversion in good yields and have minimized formation of the bis-coupling product. The newly identified protocol involving the use of a syringe pump has been extended to other symmetrical diiodo(hetero)arenes. [ABSTRACT FROM AUTHOR]

Research literaturature since 1997 related to the selective chemical transfomations of 1,4-diiodo-2,3,5,6-tetrafluorobenzene (or DITFB, 1 ), a polyfluorinated building block of major importance, is reviewed to reveal a major void of reliable methodologies. [ABSTRACT FROM AUTHOR]

A novel red fluorescent push-pull system able to generate an intramolecular charge-transfer (ICT) complex was synthesized. The novel dye ( R-POX ) combines some structural features which are rarely encountered in the design of other push-pull systems: hexyl-substituted phenoxazine as donor moiety, divinylketone as π-linker, and p- fluorobenzene as electron acceptor group. The relationship between the structural motif, photo-physical and electrochemical properties by UV–Vis absorption, photoluminescence and cyclic voltammetry was thoroughly investigated both as red dopant in poly(methylmethacrylate) (PMMA) or polyimide (PI) matrix, and non-doped host emitter. The molecular rigid cores of the synthesized dye formed supramolecular rod-like structures in condensed phase with a strong impact on the emissive centers. The aggregation was totally suppressed when the dye was used as dopant in an amorphous polymeric matrix, such as PMMA or PI. Electrochemical measurements revealed the dye ability for both hole and electron injection and transport. The fluorescence emission was found to be highly sensitive to solvent polarity, rendering blue-green, yellow, orange and red light emission in different organic solvents. The absolute fluorescence quantum yield reached 39.57% in solution, and dropped to 1.2% in solid state and to 14.01% when the dye was used as dopant in PMMA matrix. According to the available CIE 1931 standard, R-POX emitted pure and saturated red light of single wavelength with chromaticity coordinates very close to those of National Television System Committee (NTSC) standard red colour. The R-POX photo-optical features were compared to those of the commercial red emitter 6, 13-diphenylpentacene. [ABSTRACT FROM AUTHOR]

Two narrow band-gap small molecules with D(A-Ar) 2 framework, namely DMPh(DPP-Py) 2 and DFPh(DPP-Py) 2 , were designed and synthesized for high-performance small molecule organic solar cells (SMOSC), in which the 1,4-dimethoxybenzene (DMPh) and 1,4-difluorobenzene (DFPh) were employed as rigid donor cores, respectively, and the pyrenere (Py) unit is selected as terminal-capping groups on an electron-deficient diketopyrrolopyrrole (DPP)-based linear backbone. The impacts of the fluorine-sulfur (F⋯S) atoms and oxygen-sulfur (O⋯S) atoms noncovalent interaction on their absorption spectra, molecular energy levels, morphological properties, hole mobilities and photovoltaic properties were investigated thoroughly. The fluorinated DFPh(DPP-Py) 2 possess a relatively lower-lying HOMO energy level, better miscibility of the blend with PC 71 BM, as well as higher mobility in comparison with those of the methoxyled DMPh(DPP-Py) 2 . As a consequence, the OSCs devices based on DMPh(DPP-Py) 2 and DFPh(DPP-Py) 2 exhibited PCEs of 5.47% and 7.54%, respectively. Obviously, the device based on DFPh(DPP-Py) 2 presented a better performance, which should be ascribed to the improved simultaneously V oc of 0.77 V, J sc of 15.3 mA cm −2 , and FF of 64%. The results indicated that the choice of the fluorination designation on the molecular backbone is an effective approach to develop D(A-Ar) 2 type small molecule donors for highly efficient solar cell applications. [ABSTRACT FROM AUTHOR]

Background irradiated electrons in photoelectron spectra are known to take place under the ultraviolet light irradiation. Therefore, it deserves discussing the reduction of such electrons in the electron spectra in this work. The main problem present in these electron spectra will largely be overcome through a workflow and process, namely, a combination method of rotating images with angular-tailored and subtracting noise electrons of images which gives rise to non-noise electron peaks. An improved SNR is readily obtained for REMPI-SEVI spectra of 3-bromofluorobenzene (3-Br-FPh) compared with no noise–subtracted and no-angular-tailored spectra. More details are given including electron velocity-map imaging analysis on S − , CuOH − (H 2 O), and 3-Br-FPh in the following sections. [ABSTRACT FROM AUTHOR]

A series of novel N -pyrrolyl-, N -(2,5-dimethyl)pyrrolyl- and N -(2,5-dithiophen-2-yl)pyrrolyl- partially fluorinated and/or fully substituted benzenes have been prepared by the nucleophilic substitution of fluorine (S N Ar) in hexafluorobenzene, 1-pentafluorophenyl-1H-pyrrole; 2,5-dimethyl-1-pentafluorophenyl-1H-pyrrole; 2,5-di(thiophen-2-yl)pentafluorophenyl and 2,3,5,6-tetrafluoroterephtalonitrile. The observed substitution pattern indicates the gradual defluorination of particular fluorine atoms depending on the nature and amount of the used nucleophile (pyrrole/NaH vs. 2,5-dimethylpyrrole/NaH). [ABSTRACT FROM AUTHOR]

At present, actual problem is to measure the flow of liquid and gaseous hydrocarbons without separation. One of the problems associated with the definition of the parameters of motion multiphase mixtures, is to determine the parameters flows liquid and gaseous hydrocarbons of multiphase flow for multiphase meters that make measurement without separation of the hydrocarbon mixture into individual phases and fractions. The use of such flow measuring devices can greatly simplify the process of measuring the flow of hydrocarbon mixture to make it more responsive (including the use for mobile multiphase flow and compact subsea devices) and more cost effective. The object of this study is multiphase flowmeter flow path and the processes occurring along the axis of the flowmeter. the Venturi tube, designed to measure the volumetric rate flowing therein medium using differential pressure, is considered as a measuring means. Based on the results of numerical solution of equations for steady turbulent flow of compressible multiphase flow the accuracy of measurement of pressure along the axis measuring part of the Venturi tube and the pressure unit is estimated, and also the flow of multiphase medium is considered. [ABSTRACT FROM AUTHOR]

The S 1 ← S 0 ( A ̃ 1 B 2 ← X ̃ 1 A 1 ) electronic transition of para -chlorofluorobenzene has been investigated using resonance-enhanced multiphoton ionization (REMPI) spectroscopy. Assignment of the vibrational structure has been achieved by comparison with corresponding spectra of related molecules, via quantum chemical calculations, and via shifts in bands between the spectra of the 35 Cl and 37 Cl isotopologues. In addition, we have also partially reassigned a previously-published spectrum of para -dichlorobenzene. [ABSTRACT FROM AUTHOR]

We report herein on palladium-catalyzed direct arylation of (poly)fluorobenzene derivatives in the presence of 2-halopyridines for the one-step synthesis of 2-[(poly)fluorinated aryl]pyridine derivatives. The reactivity of 2-bromopyridines strongly dependents on its substituents at C6 position. The reaction proceeds nicely using a diphosphine palladium catalyst, and potassium pivalate/dimethylacetamide (PivOK/DMA) as catalytic system. The reaction was regioselective and occurred at the ortho -position of fluorine atoms. [ABSTRACT FROM AUTHOR]

In this paper, a non-fullerene electron acceptor, SF(DPPFB) 4 , which owns a spirobifluorene core and four diketopyrrolopyrrole (DPP) arms end capped by 4-fluorobenzene, is designed and synthesized for solution-processable organic solar cells (OSCs). SF(DPPFB) 4 shows similar absorption bands as those of its non-fluorinated parent compound, SF(DPPB) 4 . However, the terminal fluorine atoms reduce the energy levels of SF(DPPFB) 4 , especially, its lowest unoccupied molecular orbital level decreases by 0.04 eV than that of SF(DPPB) 4 , which enlarges the energy offset between the electron donor and acceptor, favorable for the dissociation of excitons in OSCs. Moreover, the fluorination improves the electron mobility of SF(DPPFB) 4 . Thus, the OSCs with poly(3-hexylthiophene) as the electron donor and SF(DPPFB) 4 as the electron acceptor can provide a maximum power conversion efficiency of 4.42%, with a lifted short-circuit current ( J sc ) of 8.48 mA cm −2 . [ABSTRACT FROM AUTHOR]

A new type of highly fluorinated monolith (HFM) was fabricated and used as adsorbent of multiple monolithic fiber solid-phase microextraction (MMF-SPME). To prepare the HFM, a fluorinated monomer, 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl acrylate was in situ copolymerized with dual cross-linkers (divinylbenzene and ethylenedimethacrylate). The fabrication parameters including the content of monomer and porogenic solvent in the polymerization mixture were optimized to obtain expected extraction performance and life span. The physicochemical properties of the HFM were systematically investigated with elemental analysis, infrared spectroscopy, scanning electron microscopy and mercury intrusion porosimetry. The effective extraction of six fluorobenzenes was selected as a paradigm to demonstrate the fluorophilic characteristic of HFM/MMF-SPME. At the same time, a convenient and effective method for the determination of trace fluorobenzenes in environmental water samples was developed by coupling HFM/MMF-SPME with high performance liquid chromatography/diode array detection (HFM/MMF-SPME-HPLC/DAD). Results indicated that the limits of detection (S/N = 3) for targeted compounds were in the range of 1.09–5.88 μg/L. The intra-day and inter-day precision (relative standard deviations, n = 4, %) at two spiked concentrations were 4.2–10.6% and 6.1–10.8%, respectively. Finally, the developed method was successfully applied to the analysis of fluorobenzenes in spiked real water samples with satisfactory recoveries and repeatability. [ABSTRACT FROM AUTHOR]

A new route allowing the one-step synthesis of (2-heteroarylphenyl)tetrazole and fluorinated biphenyltetrazole derivatives is disclosed. By using 2 mol% of an air-stable diphosphine-palladium catalyst [PdCl(C 3 H 5 )(dppb)], potassium pivalate as base and dimethylacetamide as solvent, a wide range of heteroarenes ( e.g ., thiazoles, (benzo)thiophenes, furans, pyrroles, and imidazo[1,2- a ]pyridine) and polyfluorobenzenes was easily coupled with N -protected (2-bromophenyl)tetrazoles in high yields. [ABSTRACT FROM AUTHOR]

X-ray single crystal diffraction reveals that a series of cocrystals are assembled by three ring angular diazaphenanthrenes including 1,7-phenanthroline, 4,7-phenanthroline and 1,10-phenanthroline with 1,4-/1,2-diiodotetrafluorobenzenes via C—I··· N halogen bonding (XB) as main driving force. Raman shift of the symmetric C I stretching vibration coupling with ring elongation and lateral ring expansion to a lower frequency by 2 to 7 cm − 1 for 1,4-DITFB in cocrystals shows the existence of C—I··· N halogen bonding. All cocrystals phosphoresce with a distinct change of colors from yellow, orange, pink to red. Also phosphorescent lifetimes of cocrystals containing 1,4-DITFB are longer than those of others constructed by 1,2-DITFB. These phenanthrolines monomers have almost same phosphorescence wavelength (the max. at 493 nm) in β-cyclodextrin solution in the presence of bromocyclohexane as a pure physically heavy atom perturber. The results demonstrate C I··· N XB makes heavy atom effect more direct and efficient, and influences significantly the energy level of the lowest lying excited triplet states and the population of electrons to triplet state of the angular diazaphenanthrenes because of greater contribution of lone pair electrons from nitrogen to conjugation systems. Meanwhile, the XB modulates luminescent behaviors due to difference in positions of nitrogen atoms. Good coplanarity, i . e ., torsion angles being closer to 0°, in C I··· N halogen bonded binary systems also is an important factor affecting the appearance quality of cocrystals. [ABSTRACT FROM AUTHOR]

• The calculations of fluorine-fluorine, fluorine-carbon, and fluorine-proton spin-spin coupling constants (165 couplings in total) are performed for all possible fluorobenzenes ranging from fluorobenzene to hexafluorobenzene within different computational approaches based on the SOPPA, CCSD and DFT formalisms with taking into account solvent, vibrational, and correlation corrections. A good correlation of calculated couplings at all levels with experiment was established. • Solvent corrections are in average of about 0.2‒0.3 Hz in absolute value for the long-range (geminal, vicinal, and longer range) couplings involving fluorine, while they are essentially larger (up to several Hertz) for the one-bond carbon-fluorine couplings. • Vibrational corrections are even smaller, being in average of about 0.1‒0.2 Hz and alternating in sign, while they are negative and somewhat larger in absolute value (up to ‒3.9 Hz) for the one-bond carbon-fluorine couplings. • Electron correlation corrections are much more pronounced for the fluorine-fluorine and one-bond fluorine-carbon spin-spin coupling constants, reaching up to 7 and 11 Hz for these types of couplings, respectively. However, these are crucial only for the correct calculation of fluorine-fluorine couplings and are rather less important for the fluorine-carbon couplings, because the ranges of these couplings are cardinally different, being of −1.6 ± 19.2 Hz for the former and -240 ± 10 Hz for the latter. All possible fluorine spin-spin coupling constants, 19F‒19F, 19F‒13C, and 19F‒1H, in the series of 12 fluorobenzenes, ranging from fluorobenzene to hexafluorobenzene, were calculated using three different non-empirical formalisms, those based on the DFT, SOPPA, and CCSD formalisms with taking into account solvent, vibrational, and correlation corrections. Within the DFT formalism, three exchange-correlation functionals, namely KT3, M06–2X, and PBE0, were found to be most suitable for the calculation of 19F‒19F, 19F‒13C, and 19F‒1H couplings. Among computational schemes based on the SOPPA and CCSD formalisms, the most efficient and accurate scheme for the calculation of 19F‒13C and 19F‒1H SSCCs is the SOPPA(MP2), while that for the 19F‒19F coupling constants, it is the composite scheme SOPPA(MP2)/CCSD. [Display omitted] [ABSTRACT FROM AUTHOR]

The existence of non-covalent interactions between iodine and three haloarenes, namely, fluorobenzene ( FB ), bromobenzene ( BB ) and iodobenzene ( IB ) with iodine in n-hexane medium at 303 K was established from the trend in acoustical properties and excess thermo acoustical parameters with concentration. Formation constants of the three ternary mixtures were determined by a novel ultrasonic method employing the equation proposed by Kannappan. The trend in K values of the three complexes agreed well with the trend obtained by spectral methods by earlier workers. Dispersion and long-range corrected ω-B97X-D3 functional was used to calculate the both π and halogen bonded types of interactions. NBO analyses were used to quantify the nature of the stabilizing interactions that exist in the complexes of haloarenes with I 2 . Our computed results are in good agreement with the observations in ultrasonic method. [ABSTRACT FROM AUTHOR]

• Organic conjugated polymers is expanding primarily due to the possibility of doing modifications and powerful variations in the polymeric backbone. • Donor-Acceptor copolymers P(BT-4FPH), P(TH-4FPH) and P(3METH-4FPH), were designed and synthesized by the direct arylation polymerization method, theoretical investigations were carried out using Gaussian 09 with two levels of density functional theories B3LYP and HSE06. • Results obtained from the HSE06/6–31 G (d,p) basis set was more related to the experimental data. The copolymer was characterized by FT-IR, 1H NMR, and TG. • Among the synthesized copolymers P(BT-4FPH) exhibited a lower band gap both theoretically and experimentally. • The third-order non-linear optical properties were studied by the OA Z-scan technique at 532 nm. Copolymers showed RSA non-linear absorption with a lower optical limiting threshold. Thus, the copolymers developed are promising material for optoelectronic devices. Low band gap donor-acceptor type π-conjugated conducting polymers P(BT-4FPH), P(3METH-4FPH) and P(TH-4FPH) were theoretically designed using Gaussian 09 with two hybrid functionals B3LYP, HSE06/6–31 G (d,p) basis set. Oscillator strength and excitation energy of the monomers were determined by TD-DFT/B3LYP/6–31 G (d,p) method. Copolymers were synthesized by the direct arylation polymerization method. Structural characterization was done by FTIR and 1H NMR spectra. Thermal stabilities of the copolymers were evaluated by TG. The molecular weights of the copolymers were obtained by Gel permeation chromatography. Cyclic voltammetry (CV) was used to observe the electrochemical band gaps of the copolymers. Theoretical observations from HSE06/6–31 G (d,p) method supported the experimental results. Third-order non-linear optical properties and optical limiting effect of the copolymers were studied at different laser intensities using the open-aperture Z-scan technique at 532 nm in DMSO. P(BT-4FPH) exhibited strong optical non-linearity with reverse saturable absorption when compared with P(3METH-4FPH) and P(TH-4FPH) with non-linear absorption coefficient β = 1.20 × 10−8 m/W at 20 µJ. Optical threshold values obtained for the copolymers were low which indicated that the polymers could be used for optical power limiting devices. Among the three synthesized copolymers, P(BT-4FPH) exhibited higher molecular weight, lowest electrochemical band gap and showed strong non-linear absorption with lowest optical threshold value of 0.009 GW/cm2 at 10 µJ due to the increased delocalization of π- electrons over the conjugated backbone of donor-acceptor units. [Display omitted] [ABSTRACT FROM AUTHOR]

Three novel copolymers ( PTTAFBT-C0 , PTTAFBT-C1 and PTTAFBT-C2 ) based on thieno[3,2- b ]thiophene and 5-alkoxy-6-fluorobenzo-[ c ][1,2,5]thiadiazole (AFBT) bearing branched alkoxy chains with varied branching positions are synthesized. The influences of the bifurcation positions on intermolecular stacking, charge mobility, film morphology and photovoltaic performance are systematically investigated. 2D-GIWAXS analyses of the optimized polymer:PC 71 BM blend films exhibit the crystallinity increases from PTTAFBT-C0 to PTTAFBT-C1 and PTTAFBT-C2 is more prone to form the edge-on orientation than PTTAFBT-C1 , which result in a dramatic difference in film morphologies. TEM image of PTTAFBT-C1 :PC 71 BM blend films exhibits a suitable morphology with favorable interpenetrating networks, which is in favor of high performance. The best PCE of 5.67% with a device configuration of ITO/PEDOT: PSS/ PTTAFBT-C1 :PC 71 BM/LiF/Al under AM 1.5G solar radiation (100 mW cm −2 ) is achieved. These results indicate that higher PCE can be obtained by adjusting the bifurcation points of the branched side chains away from the polymer backbone. [ABSTRACT FROM AUTHOR]

The reactivity of protonated 1,4-difluorobenzene C 6 H 5 F 2 + as a Proton Transfer Reaction (PTR) precursor in a compact Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometer has been evaluated in comparison with H 3 O + precursor. The C 6 H 5 F 2 + ion reacts with unsaturated and oxygenated VOCs by proton transfer. Kinetic studies have shown that this precursor induces less fragmentation than H 3 O + , so that the protonated molecule is detected in cases where H 3 O + leads to total fragmentation following proton transfer. For the analytes considered the reaction rate constants are ca 80% of the capture rate constants. Use of C 6 H 5 F 2 + in trace analysis conditions has been tested on a standard mixture of VOCs diluted in air. The protonation rates measured in this way using both precursors depend linearly on concentration, allowing quantitative analysis. Their ratio to theoretical capture rates is generally slightly higher with C 6 H 5 F 2 + than with H 3 O + . [ABSTRACT FROM AUTHOR]

We have successfully synthesized π-conjugated microporous polymers (CMPs) via direct arylation of fluoroarenes with 2,4,6-tris(4-bromophenyl)-1,3,5-triazine. Both 1,2,4,5-tetrafluorobenzene and 1,3,5-trifluorobenzene were good monomers to give the networks, CMP1 and CMP2 , respectively. Characterization of the insoluble materials was successfully achieved by high performance solid-state 13 C and 19 F CP/MAS NMR spectroscopy. The signals appeared in the aromatic region. No end group signals were observed in the 13 C NMR spectrum of CMP1 , but CMP2 showed the unreacted C–H signal of the trifluorobenzene unit. CMP2 showed higher Brunauer–Emmett–Teller (BET) surface area than CMP1 . The number of branch controlled (or tailored) the porosity of the polymer networks. The polymers have microporocity with CO 2 capture capacity. The CO 2 capture capacity of CMP2 (16.75 cm 3 g -1 ) was higher than that of CMP1 (11.49 cm 3 g -1 ) at 1.0 bar. [ABSTRACT FROM AUTHOR]

The Lewis base-promoted alkynylation of fluorobenzenes using trimethylsilylacetylenes studying the reactivity as a function of the number of fluoride groups is described. The reaction of 1-(pentafluorophenyl)- and 1-(3,4,5-trifluorophenyl)-2-phenylacetylenes and 1-(4-methoxyphenyl)-2-trimethylsilylacetylene with CsF/18-crown-6 in DMSO gave the alkynylated products in moderate to good yields with high regioselectivity under mild conditions. However, the 3,4-difluorophenyl derivative showed low reactivity. [ABSTRACT FROM AUTHOR]

Samples of locally sourced UK Diesel fuel spiked with the two organic compounds 2-(butan-2-yl)-1-(decyloxy)-4-(triphenylmethyl)benzene (TPMB) and 1,3-dibromotetrafluorobenzene (BFB) were subjected to laboratory-scale distillations to assess the suitability of TPMB and BFB as effective markers of Diesel fuel. Industrial-scale distillations of these spiked Diesel samples were performed to establish whether TPMB and BFB could be successfully and cost-effectively separated from Diesel on a significantly larger scale. Diesel distillate does not contain any TPMB; newly formulated performance criteria of an ideal, distillation resistant fuel marker clearly reject TPMB as a marker suitable for the tagging of Diesel. In contrast, BFB is retained in all fractions of distilled Diesel and largely satisfies the performance criteria of a distillation resistant fuel marker. BFB consequently functions as a significantly better fuel marker than TPMB for the tagging of Diesel. It is demonstrated that distillation is also a highly effective means of removing current overt dye markers. Conservative estimates suggest that an appropriately equipped laundering facility for the distillative removal of fuel markers or vice versa fuel from marked Diesel offers the potential of generating a vastly lucrative, multi-million pound annual profit. [ABSTRACT FROM AUTHOR]

We report, herein, on palladium-catalyzed direct arylation of difluorobenzenes and dichlorobenzenes bearing benzoxazole or benzothiazole moieties, which don't act as directing groups. With moderate electron-withdrawing substituents on the aryl bromides as coupling partners, the reaction proceeds nicely using phosphine-free PdCl 2 catalyst, and potassium pivalate/dimethylacetamide (PivOK/DMA) as catalytic system. The reaction was regioselective and occurred at the less hindered ortho -positions of fluorine or chlorine atoms. [ABSTRACT FROM AUTHOR]

Owing to their low cost, easy processing, and the possibility of flexible fabrication, polymer light-emitting diodes (PLEDs) are emerging as an important class of materials. Despite promising characteristics, the relatively easy ionization of the well-known low-work-function cathodes such as Ca and Ba prevents the full usage of these materials. Herein, we report the syntheses of three alcohol-soluble conjugated polymers with different conjugation lengths and electron affinities as electron injection and transport materials for PLEDs: poly[9,9-bis(2-dihexylaminoethoxy)fluorene-co-tetrafluorobenzene] (PFOH-1), poly[9,9-bis(2-dihexylaminoethoxy)fluorene-co-thiophene] (PFOH-2), and poly[9,9-bis(2-dihexylaminoethoxy)fluorene-co-benzo-thiadiazole] (PFOH-3). For comparison, devices using Al, Ca, and Al cathodes were also fabricated. The device based on the Al cathode showed lower performance with a luminescence efficiency of 0.93 cd/A and a luminance of 248 cd/m 2 ; that based on the low-work-function metal Ca as the cathode showed a near-threefold increase in luminescence efficiency at 2.51 cd/A and brightness at 856 cd/m 2 owing to greatly enhanced electron injection from the cathode; and the device employing the PFOH-3/Al cathode exhibited a luminescence efficiency of 2.35 cd/A and a brightness of 667 cd/m 2 at a current density of 35 mA/cm 2 , which is comparable with the performance of the device with the Ca cathode. [ABSTRACT FROM AUTHOR]

[Display omitted] This study reports the development and scope of catalytic enantioselective 5- endo -trig bromocycloetherification of six-membered unactivated alkenes having a hydroxyethyl group. The proposed reaction occurs in a chiral anionic phase-transfer catalytic system using a combination of a binaphthol-based chiral phosphoric acid and a derivative of DABCO bromine complex to provide bicyclic tetrahydrofuran-fused 6-membered products, which bear a bromo group at the bridgehead position with complete diastereoselectivity and good to high enantioselectivity. Results show that the enantioselectivity depends on the solvent system and substituents at the 3,3′-position of the catalyst. Thus, the best result can be obtained using a catalyst that has 2,4,6-tricyclohexylphenyl groups at the 3,3′-positions in a mixture of fluorobenzene and n -heptane. In addition, the construction of a quaternary carbon center with the retention of configuration via a radical mediated allylation of the tertiary bromo group in the product was reported. [ABSTRACT FROM AUTHOR]

Aryl carbon–chlorine (Ar–Cl) bond cleavage has been achieved with rhodium(III) tetrakis-4-tolylporphyrin chloride (Rh(ttp)Cl) to give Rh(ttp)Ar. For 4-chlorofluorobenzene, the aryl carbon–fluorine (Ar–F) bond cleavage competes with the Ar–Cl bond cleavage. Mechanistic investigations show that the Ar–Cl bond cleavage goes through metalloradical ipso -substitution mechanism, while the Ar–F bond cleavage goes through nucleophilic aromatic substitution. The selectivity of the Ar–F or Ar–Cl bond cleavage can be controlled by tuning the temperature and substrate concentration. [ABSTRACT FROM AUTHOR]

A facile and efficient method to synthesize fluorinated aryl ethers with polyfluorobenzenes and carbonates without metal catalyst has been developed. Selective C–F bond and aryl fragment of carbonate participate in the reaction. The desired products were obtained in moderate to excellent yields with good substrates compatibility. [ABSTRACT FROM AUTHOR]

Molecular modeling was performed on a triazolo quinazoline lead compound to help develop a series of adenosine A 2A receptor antagonists with improved hERG profile. Superposition of the lead compound onto MK-499, a benchmark hERG inhibitor, combined with p K a calculations and measurement, identified terminal fluorobenzene to be responsible for hERG activity. Docking of the lead compound into an A 2A crystal structure suggested that this group is located at a flexible, spacious, and solvent-exposed opening of the binding pocket, making it possible to tolerate various functional groups. Transformation analysis (MMP, matched molecular pair) of in-house available experimental data on hERG provided suggestions for modifications in order to mitigate this liability. This led to the synthesis of a series of compounds with significantly reduced hERG activity. The strategy used in the modeling work can be applied to other medicinal chemistry programs to help improve hERG profile. [ABSTRACT FROM AUTHOR]

A range of cationic rhodium bisphosphine η 6 -fluorobenzene (fluorobenzenes = C 6 H 6− n F n , n = 1–3) and related complexes have been synthesized and characterized. These complexes act as useful organometallic precursors for catalysis or further synthetic elaboration. The relative binding affinity of the arene ligands has been investigated using Electrospray Ionisation Mass Spectrometry (ESI–MS) and two different collision-induced dissociation (CID) techniques. The influence of arene fluorination upon arene binding affinity is discussed as well as the comparison of different bis–phosphine ligands with regard to bite angle and phosphine substitution. We show that this simple technique allows fast and easy comparison of the binding affinity of arene ligands to cationic organometallic fragments. [ABSTRACT FROM AUTHOR]

Synthesis of pentafluorobenzenesulfonyl bromide from pentafluorobenzenethiol, bromine and hydrogen peroxide is presented. Reactions of pentafluorobenzenesulfonyl bromide with primary alkenes (1-hexene, 3-chloro-1-propene and 3-bromo-1-propene) in solvent-free conditions are described. [ABSTRACT FROM AUTHOR]

Vapor pressures of 2-, 3-, and 4-halogen-substituted fluorobenzenes (halogen = Cl, Br, and I) were measured by the transpiration method. Molar standard enthalpies of vaporization were calculated from temperature dependences of vapor pressures. New enthalpies of vaporization at 298 K and those available from literature were tested for consistency by correlation gas-chromatography and evaluated by group-additivity method. Contributions to vaporization due to mutual interactions of halogens on the benzene ring were derived and recommended for prediction vaporization enthalpies of halogen-substituted aromatics. [ABSTRACT FROM AUTHOR]

The qualitative and quantitative quality of DFT methods combined with different basis sets in computing the J-coupling of the types 1 J(C–F) and n J(F–F) are investigated for the fluorobenzene and fluoropyridine derivatives. Interestingly, all of the computational methods perfectly reproduced the experimental order for n J(F–F) but many failed to reproduce the experimental order for 1 J(C–F) coupling. The functional PBEPBE gives the best quantitative values that are closer to the experimental spin–spin coupling when combined with the basis sets aug-cc-pVDZ and DGDZVP but is also part of the methods that fail to perfectly reproduce the experimental order for the 1 J(C–F) coupling. The basis set DGDZVP combined with all the methods except with PBEPBE perfectly reproduces the 1 J(C–F) experimental order. All the methods reproduce either the positive or the negative sign of the experimental spin–spin coupling except for the basis set 6-31+G(d,p) which fails to reproduce the experimental positive value of 3 J(F–F) regardless of what type of DFT methods was used. The values of the FC term is far higher than all other Ramsey terms in the one bond 1 J(C–F) coupling but in the two, three and four bonds n J(F–F) the values of PSO and SD are higher. [ABSTRACT FROM AUTHOR]

Isomers, particularly those with similar geometries, provide an interesting mechanism for studying solute–solvent interactions via their diffusion properties. Here nuclear magnetic resonance (NMR) was used to measure the self-diffusion of difluorobenzene isomers in water–monohydric-alcohol systems (i.e., methanol, ethanol, and tert -butanol), at a range of mole fractions for each solvent system. The diffusion behaviour of the difluorobenzene isomers was different to the previously studied dihydroxybenzene and diaminobenzene isomers. While there is immediate usefulness to mixture analysis by the separation of similar molecules such as isomers using solvent modulation, the comparable structure of the three sets of disubstituted benzene isomers allows a comparison of solvent effects on diffusion. It was found that the different positions and functional groups had a significant effect on the diffusion of the isomers. The effect of substituent position, and the type of functional group on the interaction with the mixed solvent has been examined here. [ABSTRACT FROM AUTHOR]

An efficient method for the one-pot synthesis of secondary and tertiary N -homoallylic carbamates using catalytic amount of HBF 4 ·OEt 2 is described. The reaction proceeded smoothly to afford the corresponding N -homoallylic carbamates in good to high yields. Operationally simple and easily scalable features make this method more practical over existing methods. Use of HBF 4 ·OEt 2 as an acid catalyst also proves the catalytic activity of fluorinated acid catalyst in this important organic transformation. [ABSTRACT FROM AUTHOR]

[Display omitted] • New fluorinated polyether-based organogels were prepared and charcaterized. • The photophysical properties showed strong emission and solvatochromism. • Polyethers organogels showed high ability to gelate solvents into nanofibers. • Supramolecular organogels showed thermal stability and high reversibility. • The polyethers displayed nematic and smectic mesophases. Supramolecular organogels that respond to external stimuli have been extensively investigated; however, assembling a liquid crystal-based fluorescent gel with an efficient thermoreversible activity is a difficult challenge. Various pentafluorobenzene-containing aromatic adducts have been synthesized via nucleophilic aromatic substitution (S N Ar), which is highly regio-selective to para positions. In order to prepare calamitic liquid crystals, those pentafluorobenzene-functionalized 1, 3, 4-oxadiazole aromatic adducts are a perfect choice. Novel fluoroaryl(FA)-containing 1, 3, 4-oxadiazole (Ox) main-chain polyether (PE) (FAOx@PE) were synthesized employing in situ S N Ar as a practical technique for the synthesis of fluorescent liquid crystals with perfluoroaryl groups and ether bonds. The perfluoroaryl group was inserted into the 1, 3, 4-oxadiazole compound by the reaction of potassium pentafluorobenzoate and tetrazole-containing biphenyl using a DCC-assisted decarboxylating coupling. Using 1H/13C/19F NMR and FTIR spectroscopic techniques, the chemical structure of FAOx@PE was determined. Differential scan calorimeter (DSC), X-ray diffraction (XRD) and polarization microscope (POM) were utilized to examine the liquid crystal mesophases. The absorption and emission spectral patterns were detected in the ultraviolet–visible range demonstrating solvatochromic activity. Scanning electron microscope (SEM) was employed to inspect the nanofibrous morphology of FAOx@PE organogel. [ABSTRACT FROM AUTHOR]

Two novel copolymer donors, namely PBDTTS-2FQx and PBDTTS-2ClQx, with identical molecular backbone but different halogen side chains atoms (F and Cl) on quinoxaline (Qx) acceptor units were firstly developed. The processed binary devices based on PBDTTS-2ClQx blend film achieved an impressively PCE of up to 16.1%. [Display omitted] • The effects of different side chains atoms (i.e., F and Cl) on the properties of copolymers and relevant active layers were studied. • The binary OSCs based on PBDTTS-2ClQx with chlorinated side chains achieved a high device efficiency of up to 16.1%. • The impressive PCE of 16.1% is by far one of the highest values for binary OSCs with the Qx-based copolymer as donors. The simple halogenation strategy of side-chains has been proven an effective approach to boost the photovoltaic performance of organic solar cells (OSCs). Herein, two novel D-A copolymer donors, namely PBDTTS-2FQx and PBDTTS-2ClQx, comprising an alkylthiothiophene benzodithiophene (BDTTS) as donor unit, alkyl substituted thiophene as the π-bridges and an identical molecular framework but alkoxy substituted fluorobenzene (or chlorobenzene) side chains on the quinoxaline (Qx) as acceptor units, are first developed and compared in parallel. The PBDTTS-2ClQx with chlorobenzene side chains on the Qx unit exhibits a distinct redshifted absorption, suppressed energy levels, increased extinction coefficient and electron mobility compared with the counterpart PBDTTS-2FQx bearing fluorobenzene side-chains on the Qx unit. After blended with BTP-eC9 as non-fullerene acceptor (NFA), the blend film of PBDTTS-2ClQx:BTP-eC9 shows higher and balanced hole/electron mobilities, more favorable aggregation, as well as less charge carrier recombination and better molecular order. As a result, the OSCs based on PBDTTS-2ClQx:BTP-eC9 deliver an impressive power conversion efficiency (PCE) of 16.1% with simultaneously increased fundamental parameters, while the PBDTTS-2FQx-based OSCs exhibits only a PCE of 12.2%. The impressive PCE of 16.1% is by far one of the highest values for binary OSCs with the Qx-based copolymer as donors. This work reveals that chlorine side-chain engineering of the Qx-based copolymer donors is a simple and effective approach to further improve their photovoltaic performance. [ABSTRACT FROM AUTHOR]

[Display omitted] The kinetics of halide exchange in cyclopentadienylruthenium bis(triarylphosphine) halide complexes CpRu(PAr 3) 2 X (1a X = Cl, 1b X = Br, 1c X = I; X′= Cl, Br, Ar = C 6 H 5 , 2 Ar = p- CH 3 OC 6 H 4 , X = Cl, X′= Br and 3 Ar = p- FC 6 H 4 , X = Cl, X′ = Br) have been measured and the results interpreted with respect to two possible mechanisms: halide dissociation vs phosphine dissociation. Halide exchange between n Bu 4 NX′ and 1 – 3 in fluorobenzene under pseudo-first order conditions is found to be first order in 1 – 3. Relative rates of halide exchange follow the order: 1a > 1b > 1c > 2 ≈ 3 with activation parameters ΔH† = 117 ± 6 kJ/mol and ΔS† = 44 ± 18 J/mol-K (1a , X′ = Br) and ΔH† = 120 ± 14 kJ/mol ΔS† = 50 ± 45 J/mol-K (1b , X′ = Cl). Plots of k obs vs [X′–] for 1 and 2 are consistent with a two-term rate law where k obs = (k 1 + k 2 [X′–]) while reactions of 3 are independent of the halide concentration. The rate data are consistent with phosphine dissociation as the rate determining step followed by a slightly faster reaction with halide ions where the dissociated phosphine competes effectively with halide for the open coordination site in a CpRu(PAr 3)X intermediate. [ABSTRACT FROM AUTHOR]