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The aryl diester compound, 2-methyl-1,4-phenylene bis(3,5-dibromobenzoate), C21H12Br4O4, was synthesized by esterification of methyl hydroquinone with 3,5-dibromobenzoic acid. A crystalline sample was obtained by cooling a sample of the melt (m.p. = 502 K/DSC) to room temperature. The molecular structure consists of a central benzene ring with anti-3,5-dibromobenzoate groups symmetrically attached at the 1 and 4 positions and a methyl group attached at the 2 position of the central ring. In the crystal structure (space group P\overline{1}), molecules of the title aryl diester are located on inversion centers imposing disorder of the methyl group and H atom across the central benzene ring. The crystal structure is consolidated by a network of C—H...Br hydrogen bonds in addition to weaker and offset π–π interactions involving the central benzene rings as well as the rings of the attached 3,5-dibromobenzoate groups.

The title compound was synthesized at a near-quantitative yield using the nucleophilic aromatic substitution of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) with perfluoropyridine (PFP). The purity and structure were determined by NMR (1H, 13C, 19F), GC-EIMS, and single-crystal X-ray crystallography.

The title compound was synthesized in near quantitative yields via initial nucleophilic aromatic substitution of pentafluoropyridine (PFP) with 4-(2-bromoethyl)phenol as a versatile precursor for ionic liquids (ILs). The purity and structure were determined using 1H, 13C, and 19F NMR and GC-EIMS.

Reaction of triplet O2 with the bridged dipotassium dicyclopentadienyl salt, ansa-[(CHBut)2(Ph2C5H2)2]K2(THF)3 1, in dry MeCN facilitated an intramolecular cyclopentadienyl ring-C to ring-C bond formation and the precipitation of the crude product 4,5-di-tert-butyl-1,3,6,8-tetraphenyl-4,5,8a,8b-tetrahydro-as-indacene 2 as an off-white solid in a 73% yield (>95% pure, 1H NMR). Characterization of 2 was carried out using multinuclear NMR spectroscopy (1H and 13C), single-crystal X-ray crystallography, FTIR spectroscopy, and thermal analytical techniques (SDT, DSC). The molecular structure consisted of a rigid, C2-symmetric six-membered ring in a chair conformation with four of the ring-C atoms fused to 1,3-diphenylcyclopentadiene rings and the other two ring-C atoms substituted with trans di-axial But groups.

The title compound was synthesized in near-quantitative yield using nucleophilic aromatic substitution of 4,4′-(hexafluoroisopropylidene)diphenol (BPAF) with perfluoropyridine (PFP). The purity and structure were determined by NMR (1H, 13C, 19F), GC–EIMS, and single-crystal X-ray crystallography.

The title compounds, 6-cyclopropyl-1,3-diphenylfulvene, C21H18, [systematic name: 5-(cyclopropylmethylidene)-1,3-diphenylcyclopenta-1,3-diene], 1, and 6-(2,3-dimethoxynaphthyl)-1,3-diphenylfulvene, C30H24O2, {systematic name: 5-[(3,4-dimethoxynaphthalen-2-yl)methylidene]-1,3-diphenylcyclopenta-1,3-diene}, 2, were prepared from 1,3-diphenylcyclopentadiene, pyrrolidine, and the corresponding aldehydes in an ethanolic solution. Each structure crystallizes with one molecule per asymmetric unit and exhibits the alternating short and long bond lengths typical of fulvenes. A network of C—H...C ring interactions as well as C—H...O interactions is observed, resulting in the compact packing found in each structure.

Improving the performance of composite energetic materials comprised of a solid metal fuel and a source of oxidizer (known as thermites) has long been pursued as thermites for pyrolant flares and rocket propellants. The performance of thermites, involving aluminum as the fuel, can be dramatically improved by utilizing nanometer-sized aluminum particles (nAl) leading to vastly higher reaction velocities, owing to the high surface area of nAl. Despite the benefits of the increased surface area, there are still several problems inherent to nanoscale reactants including particle aggregation, and higher viscosity composited materials. The higher viscosity of nAl composites is cumbersome for processing with inert polymer binder formulations, especially at the high mass loadings of metal fuel necessary for industry standards. In order to improve the viscosity of high mass loaded nAl energetics, the surface of the nAl was passivated with covalently bound monolayers of perfluorinated carboxylic acids (PFCAs) utilizing a novel fluorinated solvent washing technique. This work also details the quantitative binding of these monolayers using infrared spectroscopy, in addition to the energetic output from calorimetric and thermogravimetric analysis.

Improvements to fluoropolymer processing techniques by way of utilizing nanoparticles as drop-in processing aids have pronounced effects on bulk composite properties. In this work, we prepared fluoroalkyl-silanized silica nanoparticles (F-SiNPs, ca. 200 nm) that were solvent-blended with polyvinylenedifluoride (PVDF) in order to prepare composites with varying weight fractions. We demonstrated that the ability to functionalize SiNPs with long fluoroalkylchains that induced co-crystallization with the PVDF matrix, resulting in uniform particle dispersion and improved interlaminate adhesion. This was quantitatively investigated using calorimetry and thermogravimetric analysis, which showed a decrease in the bulk crystallinity of the virgin PVDF from 37% to 10% with minimal 10 wt % F-SiNP loading, rendering a nearly amorphous PVDF. Additional discussions in this work include the effects of various bare and fluoroalkyl-functionalized SiNP loadings on the amorphous and crystalline domains of the PVDF matrix, as well as thermal decomposition.

The syntheses and crystal structures of the title compounds, C14H8F4N2O2 and C14H8F4N2O3, are reported. In each crystal, the packing is driven by C—H...F intertactions, along with a variety of C—H...O, C—O...π, and C—F...π contacts. Hirshfeld surface analysis was conducted to aid in the visualization of these various influences on the packing: they showed that the largest contributions to the surface contacts arise from H...F/F...H interactions, followed by H...H and O...H/H...O.

Five new crystal structures of perfluoropyridine substituted in the 4-position with phenoxy, 4-bromophenoxy, naphthalen-2-yloxy, 6-bromonaphthalen-2-yloxy, and 4,4′-biphenoxy are reported, viz. 2,3,5,6-tetrafluoro-4-phenoxypyridine, C11H5F4NO (I), 4-(4-bromophenoxy)-2,3,5,6-tetrafluoropyridine, C11H4BrF4NO (II), 2,3,5,6-tetrafluoro-4-[(naphthalen-2-yl)oxy]pyridine, C15H7F4NO (III), 4-[(6-bromonaphthalen-2-yl)oxy]-2,3,5,6-tetrafluoropyridine, C15H6BrF4NO (IV), and 2,2′-bis[(perfluoropyridin-4-yl)oxy]-1,1′-biphenyl, C22H8F8N2O2 (V). The dihedral angles between the aromatic ring systems in I–IV are 78.74 (8), 56.35 (8), 74.30 (7), and 64.34 (19)°, respectively. The complete molecule of V is generated by a crystallographic twofold axis: the dihedral angle between the pyridine ring and adjacent phenyl ring is 80.89 (5)° and the equivalent angle between the biphenyl rings is 27.30 (5)°. In each crystal, the packing is driven by C—H...F interactions, along with a variety of C—F...π, C—H...π, C—Br...N, C—H...N, and C—Br...π contacts. Hirshfeld surface analysis was conducted to aid in the visualization of these various influences on the packing.

The synthesis and crystal structures of a series of 6-arylfuvlenes (fulvene is 5-methylidenecyclopenta-1,3-diene) with varying methylation patterns on the 6-phenyl substituent are reported, namely 6-(3-methylphenyl)-1,3-diphenylfulvene (C25H20), 6-(4-methylphenyl)-1,3-diphenylfulvene (C25H20), 6-mesityl-3-diphenylfulvene (C27H24) and 6-(2,3,4,5,6-pentamethylphenyl)-1,3-diphenylfulvene (C29H28). The bond lengths are typical of those observed in related fulvenes. A network of C—H...π ring interactions consolidates the packing in each structure.

Perfluoropyridine (PFPy) is an organofluorine compound that has been employed for a variety of applications, from straightforward chemical synthesis to more advanced functions, such as fluorinated networks and polymers. This can be directly attributed to the highly reactive nature of PFPy, especially towards nucleophilic aromatic substitution (SNAr). The aim of this review is to highlight the discovery and synthesis of PFPy, discuss its reactive nature towards SNAr, and to summarize known reports of the utilization and thermal analysis of PFPy containing fluoropolymers and fluorinated network materials.

The synthesis and structural properties of a series of chromium tricarbonyl `piano-stool' complexes bearing substituted pentafulvene ligands were studied. The complexes, tricarbonyl(1,3,6-triphenylfulvene)chromium(0) benzene hemisolvate, [Cr(C24H18)(CO)3]·0.5C6H6 (I), tricarbonyl[1,3-diphenyl-6-(3-vinylphenyl)fulvene]chromium(0), [Cr(C26H20)(CO)3] (II), and tricarbonyl[1,3-diphenyl-6-(pyren-1-yl)fulvene]chromium(0), [Cr(C34H22)(CO)3] (III), each have a distorted octahedral geometry, with the fulvene coordinated in a π–η2:π–η2:π–η2 fashion. Significant deviation of the exocyclic fulvene double bond from the cyclopentadiene plane accompanies coordination. Evidence of non-covalent π–π interactions was observed in both (I) and (III), with centroid-to-centroid distances ranging from 3.330 (8) to 3.494 (8) Å.

This data article describes a detailed synthetic strategy and experimental data for the synthesis of brominated fulvene chromophores as reactive precursors/monomers for conjugated organic materials. Metal-mediated coupling reactions of brominated fulvenes would result in conjugated small molecules or polymers that would find application as organic light emitting diodes (OLEDs) and photovoltaic (PV) applications.

Perfluoroaromatics, such as perfluoropyridine and perfluorobenzene, are privileged synthetic scaffolds in organofluorine methodology, undergoing a series of regioselective substitution reactions with a variety of nucleophiles. This unique chemical behavior allows for the synthesis of many perfluoroaromatic derived molecules with unique and diverse architectures. Recently, it has been demonstrated that perfluoropyridine and perfluorobenzene can be utilized as precursors for a variety of materials, ranging from high performance polyaryl ethers to promising drug scaffolds. In this work, using density functional theory, we investigate the possibility of perfluoropyrimidine, perfluoropyridazine, and perfluoropyrazine participating in similar substitution reactions. We have found that the first nucleophilic addition of a phenoxide group substitution on perfluoropyrimidine and on perfluoropyridazine would happen at a site para to one of the nitrogen atoms. While previous literature points to mesomeric effects as the primary cause of this phenomenon, our work demonstrates that this effect is enhanced by the fact that the transition states for these reactions result in bond angles that allow the phenoxide to π-complex with the electron-deficient diazine ring. The second substitution on perfluoropyrimidine and on perfluoropyridazine is most likely to happen at the site para to the other nitrogen. The second substitution on perfluoropyrazine is most likely to happen at the site para to the first substitution. The activation energies for these reactions are in line with those reported for perfluoropyridine and suggest that these platforms may also be worth investigation in the lab as possible monomers for high performance polymers.

In the title compound, [Fe(C17H12Br)2], the FeII atom is sandwiched between the eclipsed five-membered rings, with Fe...ring centroid distances of 1.649 (3) and 1.652 (3) Å. In one of the ligands, the Br atom is disordered over two locations [site occupancies = 0.839 (2) and 0.161 (2)].

The title compound, [IrCl(C12H8NO)2{(CH3)2SO}]·H3CCN or [IrCl(fppy)2(DMSO)]·H3CCN [where fppy is 4-(pyridin-2-yl)benzaldehyde and DMSO is dimethyl sulfoxide], is a mononuclear iridium(III) complex including two fppy ligands, a sulfur-coordinating DMSO ligand, and one terminal chloride ligand that define a distorted octahedral coordination sphere. The complex crystallizes from 1:1 DMSO–acetonitrile as an acetonitrile solvate. In the crystal, weak C—H...O and C—H...N hydrogen-bonding interactions between adjacent complexes and between the acetonitrile solvent and the complex consolidate the packing.

The title compound, C17H19N, is a disubstituted pentafulvene obtained from the hydroamination of 1-phenyl-3-trimethylsilylethynylcyclopentadiene and has monoclinic P21/n symmetry at 100 K. C—H...π ring interactions between neighboring molecules consolidate the packing. To the authors' knowledge, this reaction is the first reported example of a non-transition metal catalyzed hydroamination with concomitant desilylation.

The title Diels–Alder product, C52H44·2CH3CN, was obtained in trace quantity as the `endo' isomer during the synthesis of 1,3-diphenyl-6-(3,5-dimethylphenyl)fulvene. One of the two co-crystallized acetonitrile molecules is linked to the main molecule by a weak C—H...N hydrogen bond.

The title compound, C15H14Br2, obtained through the reduction of 4,4′-dibromochalcone, has monoclinic P21 symmetry at 100 K. No directional interactions could be identified in the crystal.

There are many advantages to using ionic liquids as solvents or catalysts in chemical processes. Their non-volatile characteristic and high cost, however, can pose economic, environmental, and long-term health concerns. As such, the recovery and recycling of ionic liquids have become essential to mitigate their environmental impact and to reduce costs. Numerous recovery and recycling methods have been reported, including distillation, extraction, membrane separation (a.k.a. filtration), adsorption, crystallization, gravity, and electrochemical separation. Whereas most of these methods recover both cations and anions of the ionic liquid as ion pairs, recycling methods such as single-phase ion exchange or mixed-ion exchange/non-ionic adsorption methods recover only one of the ionic liquid ions, typically the cation. These methods are frequently used for the recycling of ionic liquids having simple anions such as chloride or acetate, but are seldom employed for ionic liquids consisting of larger and more complex anions due to the added time and reagent costs necessary for the regeneration of the original ionic liquid. Herein, a combined cation and anion exchange adsorption-desorption method is presented that can effectively separate 1,2-dimethyl-3-propylimidazolium bis(trifluoromethylsulfonimide) [DMPIm][NTf2] ionic liquid from neutral impurities. More importantly, the method is capable of recovery and recycling of the original ionic liquid. Concomitant desorption of both ionic liquid ions was achieved using 0.1 M NaCl: methanol (90:10 v/v) eluent followed by isolation using liquid−liquid extraction to afford high purity products and yields of approximately 60%.

Since initially being reported, fluorinated silica nanometer-sized particles (F-SiNPs) have gained much interest in the scientific community, due to their unique properties. These properties, include, low surface energies, increased mechanical strength, thermal robustness, and chemical resistance, and are a direct result of the incorporation of fluorine with a nanometer-sized silica network. This review aims to summarize the synthetic methods that have, and are still, being utilized to prepare these specialized materials. Following this, applications for F-SiNPs, with an emphasis on recent examples, will be presented in further detail.

In the title compound, C11H9BrO, the cyclopentenone ring is almost planar with an r.m.s. deviation of 0.0097 Å. The largest inter-ring torsion angles [2.4 (3), 1.3 (3) and 3.53 (2)°] reveal only a very small twist between the rings, and suggest that the two rings are conjugated. The molecule is slightly bowed, as shown by the small dihedral angle between the rings [5.3 (1)°]. The crystal packing pattern consists of parallel sheets that stack parallel to the ac plane. Each sheet consists of molecules that pack side-to-side with the same relative orientation of phenyl and cyclopentenone rings along the a- and c-axis directions. Slipped side-to-side, face-to-face and edge-to-face interactions exist between pairs of sheets with edge-to-edge and edge-to-face O...H—C(sp2) weak hydrogen-bond contacts. A relatively short edge-to-face contact (2.77 Å) also exists between pairs of sheets.