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In this work, we study the energy flow through anharmonic coupling of vibrational modes after excitation of gas-phase fluorobenzene with a multi-THz pump. We show that to predict the efficiency of anharmonic energy transfer, simple models that only include the anharmonic coupling coefficients and motion of modes at their resonant frequency are not adequate. The full motion of each mode is needed, including the time while the mode is being driven by the pump pulse, because all the frequencies present in the multi-THz pump contribute to the excitation of the non-resonantly excited vibrational modes. Additionally, the model gives us the insight that modes with either A1 or B2 symmetry are more actively involved in anharmonic coupling because these modes have more symmetry-allowed energy transfer pathways. [ABSTRACT FROM AUTHOR]

Chemical dynamics Simulation studies on benzene dimer (Bz2) and benzene–hexachlorobenzene (Bz–HCB) as performed in the past suggest that the coupling between the monomeric (intramolecular) vibrational modes and modes generated due to the association of two monomers (intermolecular) has to be neither strong nor weak for a fast dissociation of the complex. To find the optimum coupling, four complexes are taken into consideration in this work, namely, benzene–monofluorobenzene, benzene–monochlorobenzene, benzene–trifluorobenzene (Bz–TFB), and benzene–trichlorobenzene. Bz–TFB has the highest rate of dissociation among all seven complexes, including Bz2, Bz–HCB, and Bz–HFB (HFB stands for hexafluorobenzene). The set of vibrational frequencies of Bz–TFB is mainly the reason for this fast dissociation. The mass of chlorine in Bz–HCB is optimized to match its vibrational frequencies similar to those of Bz–TFB, and the dissociation of Bz–HCB becomes faster. The power spectrum of Bz–TFB, Bz–HCB, and Bz–HCB with the modified mass of chlorine is also computed to understand the extent of the said coupling in these complexes. [ABSTRACT FROM AUTHOR]

Cross-dehydrogenative coupling (CDC) reactions have attracted attention as short-step synthetic methods for C–C bond formation. Recently, we have developed CDC reactions between naphthalene and fluorobenzene. Rather than exhibiting general regioselectivity, this reaction proceeds selectively at the β-position of naphthalene. In this study, investigation using model complexes as reaction intermediates revealed that the origin of the unique selectivity is the exclusive occurrence of reductive elimination at the β-position. Detailed studies on the reductive elimination showed that the steric hindrance of the naphthyl group and the electron-withdrawing properties of fluorobenzene determine the position at which the reductive elimination reaction proceeds. These results show that the selectivity of the C–H functionalisation of polycyclic aromatic hydrocarbons (PAHs) is determined not by the C–H cleavage step, but by the subsequent reductive elimination step. The regioselective CDC reaction was adaptable to various PAHs but was less selective for pyrene with extended π-conjugation. In fluorobenzene substrates, the F atoms at the two ortho positions of the C–H moiety are necessary for high selectivity. The substrate ranges are in good agreement with the proposed mechanism, in which the reductive elimination step determines the regioselectivity. [ABSTRACT FROM AUTHOR]

In this contribution, we present "Birch‐type", and other reductions of simple arenes by the potassium salt of an anionic magnesium dinitrogen complex, [{K(TCHPNON)Mg}2(μ‐N2)] (TCHPNON=4,5‐bis(2,4,6‐tricyclohexylanilido)‐2,7‐diethyl‐9,9‐dimethyl‐xanthene), which acts as a masked dimagnesium(I) diradical in these reactions. This reagent is non‐hazardous, easy‐to‐handle, and in some cases provides access to 1,4‐cyclohexadiene reduction products under relatively mild reaction conditions. This system works effectively to reduce benzene, naphthalene and anthracene through magnesium‐bound "Birch‐type" reduction intermediates. Cyclohexadiene products can be subsequently released from the magnesium centres by protonolysis with methanol. In contrast, the reduction of substituted arenes is less selective and involves competing reaction pathways. For toluene and 1,3,5‐triphenylbenzene, the structural authentication of "Birch‐type" reduction intermediates is conclusive, although the formation of corresponding 1,4‐cyclohexadiene derivatives was low yielding. Reduction of anisole did not yield an isolable "Birch‐type" intermediate, but instead gave a C−O activation product. Treating triphenylphosphine with [{K(TCHPNON)Mg}2(μ‐N2)] resulted in the extrusion of both biphenyl and dinitrogen to afford a magnesium(II) phosphanide [{K(TCHPNON)Mg(μ‐PPh2)}2]. Reduction of fluorobenzene proceeded via C−F activation of the arene, and isolation of the magnesium(II) fluoride [{K(TCHPNON)Mg(μ‐F)}2]. Finally, the two‐electron reduction of 1,3,5,7‐cyclooctatetraene (COT) with [{K(TCHPNON)Mg}2(μ‐N2)] yielded a complex, [{K(TCHPNON)Mg}2(μ‐COT)], incorporating the aromatic dianion (COT2−). [ABSTRACT FROM AUTHOR]

Three new coordination polymers (CPs), {[Cu(NDC)(Fbtx)(H2O)] ⋅ 1.5H2O}n (1), {[Co(NDC)(Fbtx)(H2O)2] ⋅ 0.5Fbtx}n (2), and [Co2(NDC)2(Fbtx)]n (3), were synthesized by employing acid‐base mixed ligands of rigid 1,4‐naphthalenedicarboxylic acid (H2NDC) and flexible bis(1,2,4‐triazole‐1‐ylmethyl)‐2,3,5,6‐tetrafluorobenzene (Fbtx) under both hydrothermal and microwave‐assisted reaction conditions. Single‐crystal structure analysis establishted that both compounds 1 and 2 exhibit two‐dimensional (2D) layered structures, while compound 3 features a three‐dimensional (3D) complicated framework. The geometries of metal ions vary from square pyramidal (in 1 and 3) to distorted octahedral (in 2). Topological strudy showed that compounds 1 and 2 have exposed common 4‐connected 44‐sql net, while compound 3 has made a novel 4,5‐connected net with point symbol of (43 ⋅ 62 ⋅ 7)(43 ⋅ 64 ⋅ 72 ⋅ 8). The catalytic performance of the three complexes for the solvent‐free ring‐opening polymerization of L‐lactide has been investigated. The results indicated that compound 3 with coordinatively unsaturated cobalt(II) sites showed good activity and the molecular weight of the polymer obtained was high. Moreover, the complex 3 catalyst could be recycled up to five times with the retention of both catalytic activity and crystal structure. [ABSTRACT FROM AUTHOR]

The advancement of lithium‐ion batteries (LIBs) calls for superior electrolyte design to satisfy the booming demands of energy storage markets. Despite being typically indispensable in modern electrolytes, ethylene carbonate (EC) exhibits strong affinity with Li+ and derives organic‐rich SEI, leading to sluggish interfacial dynamics and unsatisfied rate capability. Here, we construct a kinetically favorable electrolyte based on linear carbonates (DMC) and fluoroethylene carbonate (FEC) with functional non‐solvating cosolvent, fluorobenzene (FB). Specifically, DMC and FEC, as weak binding solvents, show facile interfacial kinetics. FB enables a loose coordination chemistry through dipole‐dipole interaction, further lubricating Li+ desolvation and transport through SEI at interphase, which accelerates electrochemical kinetics and enables improved rate performance (257 mA h g−1 is achieved for graphite at 6 C). Moreover, the optimized electrolyte shows decent graphite compatibility, long‐term stability (75 % capacity retention after 350 cycles for NCM622/graphite pouch cells at 1 C) and wide‐temperature adaptability (−40~160 °C). This work reveals that dipole‐dipole interaction between non‐solvating cosolvents and solvents can effectively lower desolvation energy barrier and ultimately enable good rate capability, which provides a new avenue for designing EC‐free electrolyte in high‐rate LIBs. [ABSTRACT FROM AUTHOR]

A series of small molecules, T-2FB-T-ORH, T-2FB-T-BORH, and T-2FB-T-HDRH, were synthesized to have a thiophene-flanked difluorobenzene (T-2FB-T) core and alkyl-substituted rhodanine (RH) end groups for their use as nonfullerene acceptors (NFAs) in organic solar cells (OSCs). Octyl, 2-butyloctyl (BO), and 2-hexyldecyl (HD) alkyl side chains were introduced into RHs to control the material's physical properties based on the length and size of the alkyl chains. The optical properties of the three NFAs were found to be almost the same, irrespective of the alkyl chain length, whereas the molecular crystallinity and material solubility significantly differed depending on the alkyl side chains. Owing to the sufficient solubility of T-2FB-T-HDRH, OSCs based on PTB7-Th and T-2FB-T-HDRH were fabricated. A power conversion efficiency of up to 4.49% was obtained by solvent vapor annealing (SVA). The AFM study revealed that improved charge mobility and a smooth and homogeneous film morphology without excessive aggregation could be obtained in the SVA-treated film. [ABSTRACT FROM AUTHOR]

Vibronic coupling in the first eight electronic excited states of Pentafluorobenzene (PFBz) is investigated in this article. In particular, the vibronic coupling between the optically bright ππ* and optically dark πσ* states of PFBz is considered. A model 8 × 8 diabatic Hamiltonian is constructed in terms of normal coordinate of vibrational modes using the standard vibronic coupling theory and symmetry selection rule. The Hamiltonian parameters are estimated with the aid of extensive ab initio quantum chemistry calculations. The topography of the first eight electronic excited states of PFBz is examined at length, and multiple multi-state conical intersections are established. The nuclear dynamics calculations on the coupled electronic surfaces are carried out from first principles by the wave packet propagation method. Theoretical results are found to be in good accord with the available experimental optical absorption spectrum of PFBz. [ABSTRACT FROM AUTHOR]

The reaction of perfluorobenzocyclobutene with two equivalents of 1,3,5-trifluorobenzene in an SbF5 medium followed by the treatment of the reaction mixture with water gave (3,4,5,6-tetrafluorobenzene-1,2-diyl)bis[(2,4,6-trifluorophenyl)methanone], 1-(2,4,6-trifluorophenyl)perfluorobenzocyclobuten-1-ol, and 4,5,6,7-tetrafluoro-1,3,3-tris(2,4,6-trifluorophenyl)-1,3-dihydro-2-benzofuran-1-ol. The treatment of the reaction mixture with HF gave 1,2-bis(2,4,6-trifluorophenyl)-perfluorobenzocyclobutene and 1-(2,4,6-trifluorophenyl)perfluorobenzocyclobutene. The latter compound reacted with pentafluoro-, 1,2,3,4-, or 1,2,4,5-tetrafluorobenzenes in an SbF5 medium to povide the corresponding perfluoro-1,2-diphenylbenzocyclobutenes after the treatment of the reaction mixture with HF. [ABSTRACT FROM AUTHOR]

Achieving high‐performance in all‐small‐molecule organic solar cells (ASM‐OSCs) significantly relies on precise nanoscale phase separation through domain size manipulation in the active layer. Nonetheless, for ASM‐OSC systems, forging a clear connection between the tuning of domain size and the intricacies of phase separation proves to be a formidable challenge. This study investigates the intricate interplay between domain size adjustment and the creation of optimal phase separation morphology, crucial for ASM‐OSCs' performance. It is demonstrated that exceptional phase separation in ASM‐OSCs' active layer is achieved by meticulously controlling the continuity and uniformity of domains via re‐packing process. A series of halogen‐substituted solvents (Fluorobenzene, Chlorobenzene, Bromobenzene, and Iodobenzene) is adopted to tune the re‐packing kinetics, the ASM‐OSCs treated with CB exhibited an impressive 16.2% power conversion efficiency (PCE). The PCE enhancement can be attributed to the gradual crystallization process, promoting a smoothly interconnected and uniformly distributed domain size. This, in turn, leads to a favorable phase separation morphology, enhanced charge transfer, extended carrier lifetime, and consequently, reduced recombination of free charges. The findings emphasize the pivotal role of re‐packing kinetics in achieving optimal phase separation in ASM‐OSCs, offering valuable insights for designing high‐performance ASM‐OSCs fabrication strategies. [ABSTRACT FROM AUTHOR]

The thermal stability of the [tBu3PH][HB(C6F5)3] complex, which is a product of molecular hydrogen activation by the tBu3P·B(C6F5)3 frustrated Lewis pair (FLP), was studied using a static tensimetric method with a membrane null-manometer. It was found that heating [tBu3PH][HB(C6F5)3] to temperatures above 430 K is accompanied by thermal dissociation with passing into vapor of molecular hydrogen, pentafluorobenzene, and 2-methylpropene, as the main volatile products. [ABSTRACT FROM AUTHOR]

Small molecules and polymers with conjugated structures can be used as organic optoelectronic materials. These molecules have conventionally been synthesized by cross‐coupling reactions; however, in recent years, direct functionalization of C−H bonds has been used to synthesize organic optoelectronic materials. Representative reactions include direct arylation reactions (C−H/C−X couplings, with X being halogen or pseudo‐halogen) and cross‐dehydrogenative coupling (C−H/C−H cross‐coupling) reactions. Although these reactions are convenient for short‐step synthesis, they require regioselectivity in the C−H bonds and suppression of undesired homo‐coupling side reactions. This review introduces examples of the synthesis of organic optoelectronic materials using two types of direct C−H functionalization reactions. In addition, we summarize our recent activities in the development of direct C−H functionalization reactions using fluorobenzenes as substrates. This review covers the reaction mechanism and material properties of the resulting products. [ABSTRACT FROM AUTHOR]

The thermal stability of the [tBu3PH][HB(C6F5)3] complex, which is a product of molecular hydrogen activation by the tBu3P·B(C6F5)3 frustrated Lewis pair (FLP), was studied using a static tensimetric method with a membrane null-manometer. It was found that heating [tBu3PH][HB(C6F5)3] to temperatures above 430 K is accompanied by thermal dissociation with passing into vapor of molecular hydrogen, pentafluorobenzene, and 2-methylpropene, as the main volatile products. [ABSTRACT FROM AUTHOR]

Since fluorinated organic compounds are widely used in various industries, generating large amounts of waste, an effective disposal method is increasingly demanded. In this study, fluorobenzene (FB) as a model fluorinated compound was subjected to high-pressure liquid water in a small bomb-type batch reactor in the presence of alkaline additives under hydrothermal conditions. Defluorination proceeded under alkaline hydrothermal conditions, with NaOH or KOH as the most effective additives tested. The major products were fluoride ions and phenol recovered in the aqueous product solution. For example, 90% fluorine from FB in fluoride ion form and 90% of phenol were recovered in a 1.2 mol kg−1 NaOH solution at 573 K for 120 min. The defluorination reaction was found to proceed via ipso substitution. The rate was expressed by second-order reaction kinetics with respect to concentrations of FB and OH− with an activation energy of 113.4 kJ mol−1 and a pre-exponential factor of 8.52 × 1012 mol kg−1 min−1. [ABSTRACT FROM AUTHOR]

The vapor–liquid equilibrium of the fluorobenzene–polystyrene binary polymer solution at 303.15 K was measured using a static pressure device. The vapor–liquid equilibrium of the fluorobenzene–n-octane–polystyrene ternary solution in a partial concentration range under normal pressure was determined using an improved Othmer equilibrium still, in which the octane concentration was low. Three activity coefficient models, poly-NRTL, UNIQUAC, and M-UNIQUAC-LBY, were utilized to correlate the experimental data of binary and ternary solutions, and the component activities of the fluorobenzene–n-octane–polystyrene solution at 303.15 K were predicted. A mathematical model based on the Stefan flow was developed to simulate the evaporation process of composite spherical droplets. The activity predicted by the activity coefficient model was used for numerical simulations, and compared with simulations using the activity following Raoult's law. The comparative analysis revealed that simulations based on Raoult's law and activity coefficient models yielded similar results when the mass fraction of fluorobenzene exceeded 0.6. However, in the later stages of evaporation, the calculations based on Raoult's law predicted a 10% shorter drying time for fluorobenzene. The activity coefficient models provided a better approximation and exhibited similar droplet diameter shrinking behaviors to the actual evaporation process. [ABSTRACT FROM AUTHOR]

The organic Rankine cycle (ORC) exhibits considerable promise in efficiently utilizing low-to-medium-grade heat. Currently, there is a range of organic fluids available in the market, and selecting the appropriate one for a specific application involves considering factors such as the cycle's thermodynamic performance, plant size, and compatibility with turbomachinery. The objective of our study is to examine the exergetic performance of the ORC with internal heat regeneration. We analyze 12 different organic fluids to evaluate their suitability based on parameters like exergy efficiency and heat exchange area requirements. Additionally, we investigate the need for internal heat regeneration by comparing the overall exergy performance with a simpler ORC configuration. To ensure broad applicability, we consider source temperatures ranging from 150 to 300 °C, which are relevant to industrial waste heat, geothermal sources, and solar energy. For each case, we calculate specific net power output and the UA value (heat exchanger conductance) to gain insights into selecting the appropriate organic fluid for specific source temperatures. Cyclohexane, benzene, isopropyl alcohol, and hexafluorobenzene show poor exergy efficiency due to their high boiling points. Pentane and cyclopentane provides the highest exergy efficiency of 62.2% at source temperature of 300 °C, whereas pentane is found to be the most suitable at source temperatures of 200 and 150 °C with exergy efficiency of 67.7% and 61.7%, respectively. At 200 °C source temperature, RE347mcc achieves 65.9% exergy efficiency. The choice of organic fluid for a given heat source is highly influenced by its critical properties. Moreover, the normal boiling temperature of the organic fluid significantly impacts exergy destruction during the condensation process within the cycle. [ABSTRACT FROM AUTHOR]

An efficient heterogeneous catalyst with 51.63% palladium (Pd) content is synthesized biogenically using mango leaf extract. The phytochemicals present in plant extract are proven to be responsible for the reduction of Pd (II) to Pd (0) without the need of an external reductant. The formation of Pd (0) is confirmed by XRD, UV–Visible analysis. The as-synthesized heterogeneous Pd–NPs catalyst demonstrated a remarkable catalytic activity in the direct C–H arylation of pentafluorobenzene and Hiyama cross coupling. The Pd–NPs were found to be exhibit a superior electrocatalytic activity in the hydrogen evolution reaction (HER). The Pd–NPs catalyst required an over potential − 94 mV to achieve a current density of 10 mA/cm2. Further, the Tafel slope revealed that HER proceeds via Volmer–Heyrovsky mechanism. Additionally, the mechanistic elucidation was addressed and catalyst recyclability was examined and found to be promising. [ABSTRACT FROM AUTHOR]

Nuclear dynamics in the first six vibronically coupled electronic states of pentafluorobenzene radical cation is studied with the aid of the standard vibronic coupling theory and quantum dynamical methods. A model 6 × 6 vibronic Hamiltonian is constructed in a diabatic electronic basis using symmetry selection rules and a Taylor expansion of the elements of the electronic Hamiltonian in terms of the normal coordinate of vibrational modes. Extensive ab initio quantum chemistry calculations are carried out for the adiabatic electronic energies to establish the diabatic potential energy surfaces and their coupling surfaces. Both time-independent and time-dependent quantum mechanical methods are employed to perform nuclear dynamics calculations. The vibronic spectrum of the electronic states is calculated, assigned, and compared with the available experimental results. Internal conversion dynamics of electronic states is examined to assess the impact of various couplings on the nuclear dynamics. The impact of increasing fluorination of the parent benzene radical cation on its radiative emission is examined and discussed. [ABSTRACT FROM AUTHOR]

To develop a simple and general method for improving the circularly polarized luminescence (CPL) performances of materials is of great significance. In this work, two pairs of CPL‐active homochiral metal–organic frameworks (MOFs) P/M‐Et and P/M‐Et(Cd) with eta topology are reported. In comparison to the reported isomorphic Zn‐imidazolate MOFs P‐Me and M‐Me, both luminescence dissymmetry factor (glum) and photoluminescence quantum yields (ΦPL) of P‐Et and M‐Et are largely improved by simply changing the methyl group to an ethyl group of ligands in P‐Et and M‐Et. Furthermore, the |glum| values are significantly amplified up to 0.015 from 0.0057 by introducing the non‐luminescent halogenated aromatics, while an enhanced fluorescence efficiency is observed simultaneously (from 27.2% to 47.3%). The figure of merit value is about 40 times larger than that of P‐Me and M‐Me. Similarly, the CPL performances of P/M‐Et(Cd) are improved by about five times after encapsulating fluorobenzene molecules. This work represents a new and simple method for developing CPL‐active MOF materials. [ABSTRACT FROM AUTHOR]

Syndiotactic polystyrene (sPS) incorporates low‐mass guest molecules to form a co‐crystalline structure, the δ‐phase, in which the guest molecules are confined within a nanosized space. Under such spatial constraints, what factors determine the dynamics of the guest molecules? This is an interesting question and needs to be clarified toward the functionalization of sPS/functional guest systems. In this study, the size effect of the guest molecules and use monosubstituted halobenzenes (fluorobenzene, chlorobenzene, bromobenzene, and iodobenzene) to systematically change the molecular size is focussed. Since halobenzene has a large electric dipole moment, dielectric relaxation measurements can effectively detect its molecular motion. This study aims to identify the guest dynamics in the δ‐phase by dielectric relaxation measurement and examines the molecular length dependence of the rotational relaxation times and their activation energies. [ABSTRACT FROM AUTHOR]

The vibrational spectra of 1-(chloromethyl)-4-fluorobenzene have been studied in the 4000 - 400 cm-1 and 3500 - 50 cm-1 range, by FTIR and FT-Raman, respectively. In this work, structural analysis and vibrational frequencies are performed utilizing the GAUSSIAN 09W program with DFT/B3LYP strategy with basis set 6-311++G (d, p). Least differences are noted between the measured and scaled wavenumbers. The molecular vibrational assignments are confirmed by the PED (potential energy distribution) percentage. Frontier molecular orbital, natural bond orbital and Mullikan charge examinations are employed to explain the reason for intra and intermolecular charge exchange of the molecule. Reactive sites and chemical shifts are investigated by molecular electrostatic potential map and nuclear magnetic resonance analysis. Besides, the polarizability, the first hyperpolarizability, and total dipole moment of the molecule have been computed for describing its NLO activity. [ABSTRACT FROM AUTHOR]

• 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]

H2 adds reversibly across the metal‐metal bond of [(BDI)Ga(H)−Zn(tmeda)(thf)][BAr4F] (BDI=[HC{C(CH3)N(2,6‐iPr2‐C6H3)}2]−, TMEDA=N,N,N′,N′‐tetramethylethylenediamine, BAr4F−=[B(C6H3‐3,5‐(CF3)2)4]−). Due to the stabilising effect of solvent coordination, hydrogenation products [(BDI)GaH2] and [(tmeda)ZnH(thf)][BAr4F] are favoured in THF solution, but THF‐free mixtures of [(BDI)GaH2] and [(tmeda)ZnH(OEt2)][BAr4F] are predisposed towards entropically driven dehydrogenation to [(BDI)Ga(H)−Zn(tmeda)][BAr4F] in fluorobenzene solution. [ABSTRACT FROM AUTHOR]

All possible spin–spin coupling constants, 19F–19F, 19F–13C, and 19F–1H, of pentafluorobenzene were calculated at five different levels of theory, HF, DFT, SOPPA (CCSD), CCSD, and the SOPPA (CCSD)‐based composite scheme with taking into account solvent, vibrational, relativistic, and correlation corrections. Most corrections were next to negligible for the long‐range couplings but quite essential for the one‐bond carbon–fluorine coupling constants. Hartree–Fock calculations were found to be entirely unreliable, while DFT results were comparable in accuracy with the data obtained using the wave function‐based methods. [ABSTRACT FROM AUTHOR]

A gas chromatographic headspace analysis method was used to experimentally determine gas-to-liquid partition coefficients and infinite dilution activity coefficients for two saturated (2,2,4-trimethylpentane, cyclooctane) and 3 unsaturated hydrocarbons (1,7-octadiene, 1-hexyne, 4-vinyl-1-cyclohexene), one aromatic hydrocarbon (propylbenzene), one haloalkane (1,3-dichloropropane) and four halobenzenes (fluorobenzene, chlorobenzene, 1,2-dichlorobenzene, bromobenzene), two cyclic ethers (tetrahydrofuran, 1,4-dioxane), two alcohols (1-propanol, 2-propanol), three alkyl acetates (ethyl acetate, butyl acetate, pentyl acetate), and one alkanenitrile (acetonitrile) dissolved in 2-pyrrolidone at 298.15 K. The experimental results of the headspace chromatographic measurements, combined with published solubility and infinite dilution activity coefficient data, were used to derive Abraham model correlations for describing solute transfer into 2-pyrrolidone. Mathematical correlations based on the Abraham model describe the observed partition coefficient and activity coefficient data to within 0.14 log10 units (or less). [ABSTRACT FROM AUTHOR]

Fluorobenzene (FB) is identified as a well competitive candidate co-solvent due to the low-density and low-cost, but as a hydrocarbon, the high flammability may limit its application. Based on the DHCE concepts and the strategy of combining internal-external flame retardant, we successfully solve the flammable problem of FB and develop a non-flammable electrolyte with specific solvent structure. [Display omitted] Lithium-ion batteries with Ni-rich cathode and flammable carbonate electrolytes are breeding severe safety concerns which hinds their application in electric vehicles. Herein, by introducing the fluorobenzene (FB) with low-density and low-cost as a cosolvent and bridge solvents in triethyl phosphate (TEP)-based diluted high-concentration electrolytes (DHCEs) system, we design a non-flammable electrolyte with a special solvation structure containing internal-external flame retardants. This non-flammable electrolyte not only solves successfully the incompatibility problem of TEP-based electrolyte to the Li-metal anode (LMA) and the graphite (Gr) anode, but also ensures the stable cycling of Li||LiNi 0.7 Co 0. 1 Mn 0. 2 O 2 (86% capacity retention after 120 cycles) and Gr|| LiNi 0.7 Co 0. 1 Mn 0. 2 O 2 (75% capacity retention after 200 cycles) full cells. Such design opens up a new window for developing new electrolyte systems and building safer high-energy-density batteries. [ABSTRACT FROM AUTHOR]

The presented work concerns the impact of ionization mechanisms of analytes on detection sensitivity in negative-mode ion mobility spectrometry. The main part of the work is research conducted for selected organic analytes using DT IMS in the negative mode of operation. In the negative mode of detection, two ionization mechanisms can be used: electron capture and ion–molecule reactions. The type of ionization mechanism depends on the carrier gas. The tests were carried out using two carrier gases: air and nitrogen. This allowed for a comparison of the ionization of analytes in the ion–molecule reaction mode with ionization in electron capture mode. Experiments were carried out for tetrachloromethane, trichloromethane, benzyl chloride, 1-chlorobutane, 1-chlorohexane, 1-chloropentane, tetrachlorethylene, 1-bromobutane, 1-bromopentane, 1-bromohexane, hexafluorobenzene, 2-chloroethyl ethyl sulfide (CEES), and methyl salicylate. Most of the tested substances were ionized with the formation of ionized halogen atoms (Br− or Cl−). It was found that among the tested substances, there are those whose effective ionization is possible with the use of both nitrogen and air as carrier gases, those ionized only in electron capture mode or in ion–molecule reaction mode. The important part of the work was an investigation on the effect of oxygen and water admixtures in carrier gases on the detection efficiency of selected organic compounds. [ABSTRACT FROM AUTHOR]

Demand for electronic materials with improved dielectric properties are increasing. One of the ways to reduce the dielectric constant is to incorporate fluorine atoms. In this article, a novel fluorinated epoxy resin (diglycidol ether of 2,4‐bis (1,1,1,3,3,3‐hexafluoroisopropyl) fluorobenzene (FB‐EP)) with 45.7 wt% fluorine content was synthesized from fluorobenzene, epichlorohydrin and hexafluoroacetone. The structures of desired monomers were characterized by NMR and FTIR. The epoxy resin FB‐EP was cured by copolymerization with hexahydrophthalic anhydride (HHPA) and by homopolymerization catalyzed with boron trifluoride ethylamine (BF3MEA), respectively. The curing reaction kinetics of the fluorinated epoxy and the properties of the cured materials were studied in comparison with those of common diglycidol ether epoxy resin (BADGE). The results of curing activation energy indicate that FB‐EP is reactive as the BADGE, and the four‐trifluoromethyl groups on FB‐EP do not negatively affect the cationic polymerization reactivity of the epoxy groups. The cured FB‐EP materials had lower moisture absorption, and especially lower dielectric constant (Dk, 2.23) and lower dielectric loss (Df, 0.011) in the frequency range of 8.2–12.4 GHz. This article provides a base for further study of fluorinated epoxy resin as advanced electronic materials. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Lithium (Li) metal is an ultra‐high specific capacity and low potential "holy grail" anode for developing high energy density rechargeable Li metal batteries (LMBs), but its practical application suffers from the low Coulombic efficiency (CE) and dendritic lithium growth due to its thermodynamic instability to organic solvents. Here, we report a new diluted high concentration electrolyte (DHCE) containing lithium bis(fluorosulfonyl)imide, triethyl phosphate and fluorobenzene cosolvent, which not only guarantees lithium metal anode (LMA) with an 98.4 % high average CE over 250 cycles but greatly improves Li||NMC622 cells property (70 % capacity retention after 200 cycles at C/3 current density). Therefore, this new electrolyte can provide more possibilities for developing high‐energy‐density LMBs. [ABSTRACT FROM AUTHOR]

A new ultraviolet (UV) and vacuum ultraviolet (VUV) spectrum for iodopentafluorobenzene (C6F5I) using synchrotron radiation is reported. The measurements have been combined with those from a recent high-resolution photoelectron spectroscopic study. A major theoretical study, which includes both Franck-Condon (FC) and Herzberg-Teller (HT) analyses, leads to conclusions, which are compatible with both experimental studies. Our observation that the VUV multiplet at 7.926 eV in the VUV spectrum is a Rydberg state rather than a valence state leads to a fundamental reassignment of the VUV Rydberg spectrum over previous studies and removes an anomaly where some previously assigned Rydberg states were to optically forbidden states. Adiabatic excitation energies (AEEs) were determined from equations-of-motion coupled cluster with singles and doubles excitation; these were combined with time dependent density functional theoretical methods. Frequencies from these two methods are very similar, and this enabled the evaluation of both FC and HT contributions in the lower valence states. Multi-reference multi-root configuration interaction gave a satisfactory account of the principal UV+VUV spectral profile of C6F5I, with vertical band positions and intensities. The UV spectral onset consists of two very weak transitions assigned to 1¹B1 (πσ*) and 1¹B2 (&#963&#963*) symmetries. The lowest unoccupied molecular orbital of a &#963*(a1) symmetry has a significant C-I* antibonding character. This results in considerable lengthening of the C-I bond for both these excited states. The vibrational intensity of the lowest 1¹B1 state is dominated by HT contributions; the 1¹B2 state contains both HT and FC contributions; the third band, which contains three states, two ππ*(1¹A1, 2¹B2) and one πσ*(2¹B1), is dominated by FC contributions in the ¹A1 state. In this ¹A1 state, and the spectrally dominant bands near 6.7 (¹A1) and 7.3 eV (¹A1 + ¹B2), the C-I bond length is in the normal range, and FC components dominate. [ABSTRACT FROM AUTHOR]

Nuclear Magnetic Resonance and Overhauser effect type dynamic nuclear polarization (DNP) experiments were performed to study suspensions of asphaltene in the fluorocarbons at a low magnetic field of 1.53 mT at room temperature. Asphaltene was extracted from MC800 liquid asphalt, which was Heavy Iran origin. Each sample of the solvent medium was produced at three different concentrations of asphaltene. These samples were kept for a period of seven years until DNP parameters were discovered through new DNP tests. The influence of sample age on parameters of DNP was studied and then the findings were analyzed. It was found that the  nuclear-electron coupling parameter was smaller. In low magnetic fields the nuclear-electron coupling parameter. varies from +0.5 (pure dipolar) to -1.0 (pure scalar), and new  obtained values are between these limits. New  values in our study are positive and this shows that the dipolar part of intermolecular spin-spin interactions is dominant. [ABSTRACT FROM AUTHOR]

Cyclic peptides are promising next‐generation therapeutics with improved biological stability and activity. A catalyst‐free stapling method for cysteine‐containing peptides has been developed that enables fine‐tuning of the macrocycle by using the appropriate regioisomers of fluorobenzene linkers. Stapling was performed on the unprotected linear peptide or, more conveniently, directly on‐resin after peptide synthesis. NMR spectroscopy and circular dichroism studies demonstrate that the type of stapling can tune the secondary structures of the peptides. The method was applied to a set of potential agonists for melanocortin receptors, generating a library of macrocyclic potent ligands with ortho, meta or para relationships between the thioethers. Their small but significant differences in potency and efficacy demonstrate how the method allows facile fine‐tuning of macrocyclic peptides towards biological targets from the same linear precursor. [ABSTRACT FROM AUTHOR]

Starting with 1,2-dibromobenzene and 1,2,3,4-tetrafluorobenzene, dimethyl(2-(trimethylstannyl)phenyl)phosphane, Me2P(o-C6H4)SnMe3, and dimethyl-[2,3,4,5-tetrafluoro-6-(trimethylstannyl)phenyl]phosphane, Me2P(o-C6F4)SnMe3, were synthesized and used in tin-gold exchange reactions to prepare two gold(I) dimers, bis[(2-dimethylphosphino)phenyl]di-gold(I), [Au2(μ-2-C6H4PMe2)2], and bis[(2-dimethylphosphino)-3,4,5,6-tetrafluorophenyl]di-gold(I), [Au2(μ-2-C6F4PMe2)2], respectively. Both tin precursor molecules, as well as the gold(I) complexes, were characterized by multinuclear NMR spectroscopy, CHN analysis and X-ray diffraction experiments. Both gold(I) dimers were further investigated by the means of computational as well as photophysical methods. [ABSTRACT FROM AUTHOR]

The N-phosphinoamidinato digermynes [LGe–GeL] (L = tBu2PNC(Ph)NAr, 4: Ar = 2,6-iPr2C6H3, 5: Ar = Ph) underwent reversible CO2 activation to form [LGeOC(O)GeL] (6: Ar = 2,6-iPr2C6H3, 7: Ar = Ph). Compound 7 was further reacted with diphenylacetylene and hexafluorobenzene, which proceeded through compound 5 in the first step, to form CO2, [LGeC(Ph) = C(Ph) GeL] (8), [LGeF] (9) and [LGeC6F5] (10), respectively. [ABSTRACT FROM AUTHOR]

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 R3PC(R1)E(Cl)R22 (R=Ph; R1=Me, Et, Ph; R2=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 Ph3PC(Me)Si(Cl)Me2 (1) with Na[B(C6F5)4] furnished the dimeric phosphonium‐like dication [Ph3PC(Me)SiMe2]2[B(C6F5)4]2 (8). The highly reactive, mesityl‐ or iPr‐substituted cationic species [Ph3PC(Me)SiMes2][B(C6F5)4] (9) and [Ph3PC(Et)SiiPr2][B(C6F5)4] (10) could be characterized by NMR spectroscopy. Carrying out the halide abstraction reaction in the sterically demanding ether iPr2O afforded the protonated α‐SiCP [Ph3PCH(Et)Si(Cl)iPr2][B(C6F5)4] (6 dec) by sodium‐mediated basic ether decomposition, whereas successfully synthesized [Ph3PC(Et)SiiPr2][B(C6F5)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 [Ph3PC(Me)GeMes2][B{3,5‐(CF3)2C6H3}4] (14) was obtained by treating 11 with Na[B{3,5‐(CF3)2C6H3}4] and fully characterized including by X‐ray diffraction analysis. Structural parameters indicate a strong CYlide−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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Exploiting chemical cooperation between Na and Fe(II) within the bimetallic base [dioxane ⋅ NaFe(HMDS)3] (I), (dioxane=1,4‐dioxane, HMDS=N(SiMe3)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‐C6H4)Fe(HMDS)]∞ (1), [dioxane ⋅ Na(HMDS)(2‐F‐C10H6)Fe(HMDS)]∞ (2), [dioxane ⋅ {Na(HMDS)(2,5‐F2‐C6H3)Fe(HMDS)}2]∞ (3), [dioxane ⋅ {Na(HMDS)(2,3,6‐F3‐C6H2)Fe(HMDS)}2]∞ (4), [(dioxane)1.5 ⋅ Na(HMDS)(2,4,6‐F3‐C6H2)Fe(HMDS)]2 (5), [(dioxane)1.5 ⋅ {Na(HMDS)(4‐Br‐2,6‐F2‐C6H2)Fe(HMDS)2] (6), [{(dioxane)2 ⋅ Na2Fe(HMDS)2(2‐methoxy‐6‐F‐C6H3)}+{Fe(HMDS)3}−]∞ (7) and [dioxane ⋅ {Na(HMDS)(4‐methoxy‐2,6‐F2‐C6H2)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. [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]

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 ) 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, η (0) and η (1) . For the six aromatic vapors, the Rainwater–Friend theory for the initial density dependence of the viscosity was used to derive η (0) values. Finally, reliable η (0) and also η (1) values for R134a were selected as reference values in the measured temperature range to be applied when generating a new viscosity formulation. [ABSTRACT FROM AUTHOR]

The title compound, C17H7F8N3O, was obtained via the reaction of 1-azido-2,3,4,5,6-pentafluorobenzene with 4,4,4-trifluoro-1-(p-tolyl)butane-1,3-dione using triethylamine as a base catalyst and solvent. The dihedral angles between the pentafluorophenyl (A), triazole (B) and p-tolyl (C) rings are A/B = 62.3 (2), B/C = 43.9 (3) and A/C = 19.1 (3)·. In the crystal, the molecules are linked by C--H...F and C--H...O hydrogen bonds as well as by aromatic ... stacking interactions into a three-dimensional network. To further analyse the intermolecular interactions, a Hirshfeld surface analysis was performed. [ABSTRACT FROM AUTHOR]

New photoelectron spectra (PES) and ultra violet (UV) and vacuum UV (VUV) absorption spectra of fluorobenzene recorded at higher resolution than previously, have been combined with mass-resolved (2 + 1) and (3 + 1) resonance enhanced multiphoton ionization (REMPI) spectra; this has led to the identification of numerous Rydberg states. The PES have been compared with earlier mass-analyzed threshold ionization and photoinduced Rydberg ionization (PIRI) spectra to give an overall picture of the ionic state sequence. The analysis of these spectra using both equations of motion with coupled cluster singles and doubles (EOM-CCSD) configuration interaction and time dependent density functional theory (TDDFT) calculations have been combined with vibrational analysis of both the hot and cold bands of the spectra, in considerable detail. The results extend several earlier studies on the vibronic coupling leading to conical intersections between the X2B1 and A2A2 states, and a further trio (B, C, and D) of states. The conical intersection of the X and A states has been explicitly identified, and its structure and energetics evaluated. The energy sequence of the last group is only acceptable to the present study if given as B2B2 < C2B1 < D2A1, a conclusion which is in agreement with most previous EOM-CCSD and other calculations. However, this symmetry ordering of the B and C states forces reconsideration of the nature of the PIRI spectrum. The coupling between these two states is induced by the a2 modes, v12 and v14 and we propose that the 141 band is observed in the B2B2 band in the PES for the first time, because of the improved resolution. This same assignment is given to the lowest energy band in the PIRI spectrum which was previously assigned as the origin band and further conclude that the entire PIRI spectrum is induced by v12 and v14. The relative intensities of the various Rydberg state peaks in the VUV absorption and REMPI spectra of fluorobenzene are very similar to those observed in the equivalent spectra of benzene. [ABSTRACT FROM AUTHOR]

Femtosecond Raman rotational coherence spectroscopy (RCS) detected by degenerate four-wave mixing is a background-free method that allows to determine accurate gas-phase rotational constants of non-polar molecules. Raman RCS has so far mostly been applied to the regular coherence patterns of symmetric-top molecules, while its application to nonpolar asymmetric tops has been hampered by the large number of RCS transient types, the resulting variability of the RCS patterns, and the 103–104 times larger computational effort to simulate and fit rotational Raman RCS transients. We present the rotational Raman RCS spectra of the nonpolar asymmetric top 1,4-difluorobenzene (para-difluorobenzene, p-DFB) measured in a pulsed Ar supersonic jet and in a gas cell over delay times up to ∼2.5 ns. p-DFB exhibits rotational Raman transitions with ΔJ = 0, 1, 2 and ΔK = 0, 2, leading to the observation of J −, K −, A −, and C–type transients, as well as a novel transient (S–type) that has not been characterized so far. The jet and gas cell RCS measurements were fully analyzed and yield the ground-state (v = 0) rotational constants A0 = 5637.68(20) MHz, B0 = 1428.23(37) MHz, and C0 = 1138.90(48) MHz (1σ uncertainties). Combining the A0, B0, and C0 constants with coupled-cluster with single-, double- and perturbatively corrected triple-excitation calculations using large basis sets allows to determine the semi-experimental equilibrium bond lengths re(C1–C2) = 1.3849(4) Å, re(C2–C3) = 1.3917(4) Å, re(C–F) = 1.3422(3) Å, and re(C2–H2) = 1.0791(5) Å. [ABSTRACT FROM AUTHOR]

Low‐valent (MeBDI)Al and (MeBDI)Ga and highly Lewis acidic cations in [(tBuBDI)M+⋅C6H6][(B(C6F5)4−] (M=Mg or Zn, MeBDI=HC[C(Me)N‐DIPP]2, tBuBDI=HC[C(tBu)N‐DIPP]2, DIPP=2,6‐diisopropylphenyl) react to heterobimetallic cations [(tBuBDI)Mg–Al(MeBDI)+], [(tBuBDI)Mg–Ga(MeBDI)+] and [(tBuBDI)Zn–Ga(MeBDI)+]. These cations feature long Mg–Al (or Ga) bonds while the Zn–Ga bond is short. The [(tBuBDI)Zn–Al(MeBDI)+] cation was not formed. Combined AIM and charge calculations suggest that the metal–metal bonds to Zn are considerably more covalent, whereas those to Mg should be described as weak AlI(or GaI)→Mg2+ donor bonds. Failure to isolate the Zn–Al combination originates from cleavage of the C−F bond in the solvent fluorobenzene to give (tBuBDI)ZnPh and (MeBDI)AlF+ which is extremely Lewis acidic and was not observed, but (MeBDI)Al(F)‐(μ‐F)‐(F)Al(MeBDI)+ was verified by X‐ray diffraction. DFT calculations show that the remarkably facile C–F bond cleavage follows a dearomatization/rearomatization route. [ABSTRACT FROM AUTHOR]

The pure rotational spectra of deuterated propiolic acids (HCCCOOD and DCCCOOH), 1- fluorobenzene (4-d1), and 1,2-difluorobenzene (4-d1) in their ground states have been measured using two Fourier transform microwave (FTMW) spectrometers at the University of Arizona. For 1-fluorobenzene (4-d1), nine hyperfine lines of three different ?J = 0 and 1 transitions were measured to check the synthesis method and resolution. For 1,2-difluorobenzene (4-d1), we obtained 44 hyperfine transitions from 1 to 12 GHz, including 14 different ?J = 0, 1 transitions. Deuterium quadrupole coupling constants along the three principal inertia axes were well determined. For deuterated propiolic acids, 37 hyperfine lines of Pro-OD and 59 hyperfine lines of Pro-CD, covering 11 and 12 different ?J = -1, 0, 1 transitions, respectively, were obtained from 5 to 16 GHz. Deuterium quadrupole coupling constants along the three inertia axes were well resolved for Pro-OD. For Pro-CD, only eQqaa was determined due to the near coincidence of the CD bond and the least principal inertia axis. Some measurements were made using a newer FTMW spectrometer employing multiple free induction decays as well as background subtraction. For 1-fluorobenzene (4-d1) and 1,2-difluorobenzene (4-d1), a very large-cavity (1.2 m mirror dia.) spectrometer yielded very high resolution (2 kHz) spectra. [ABSTRACT FROM AUTHOR]

We report resonance-enhanced multiphoton ionization spectra of the isotopologues fluorobenzene h5 and fluorobenzene-d5. By making use of quantum chemical calculations, the changes in the wavenumber of the vibrational modes upon deuteration are examined. Additionally, the mixing of vibrational modes both between isotopologues and also between the two electronic states is discussed. The isotopic shifts lead to dramatic changes in the appearance of the spectrum as vibrations shift in and out of Fermi resonance. Assignments of the majority of the fluorobenzene-d5 observed bands are provided, aided by previous results on fluorobenzene-h5. [ABSTRACT FROM AUTHOR]

Collisional energy transfer between vibrational ground state CO2 and highly vibrationally excited monofluorobenzene (MFB) was studied using narrow bandwidth (0.0003 cm-1) IR diode laser absorption spectroscopy. Highly vibrationally excited MFB with E' = --41000 cm-1 was prepared by 248 nm UV excitation followed by rapid radiationless internal conversion to the electronic ground state (S1→S0). The amount of vibrational energy transferred from hot MFB into rotations and translations of CO2 via collisions was measured by probing the scattered CO2 using the IR diode laser. The absolute state specific energy transfer rate constants and scattering probabilities for single collisions between hot MFB and CO2 were measured and used to determine the energy transfer probability distribution function, P(E,E'), in the large AE region. P(E,E') was then fit to a bi-exponential function and extrapolated to the low △E region. P(E,E') and the biexponential fit data were used to determine the partitioning between weak and strong collisions as well as investigate molecular properties responsible for large collisional energy transfer events. Fermi's Golden rule was used to model the shape of P(E,E') and identify which donor vibrational motions are primarily responsible for energy transfer. In general, the results suggest that low-frequency MFB vibrational modes are primarily responsible for strong collisions, and govern the shape and magnitude of P(E,E'). Where deviations from this general trend occur, vibrational modes with large negative anharmonicity constants are more efficient energy gateways than modes with similar frequency, while vibrational modes with large positive anharmonicity constants are less efficient at energy transfer than modes of similar frequency. [ABSTRACT FROM AUTHOR]