Search

Highly branched alkanes and cycloalkanes are produced via electrochemical processing of the renewable platform molecule mesityl oxide, which is a dimer of biogenic acetone. The final product is a sustainable, drop-in jet fuel.

The 5-(chloromethyl)furfural (CMF) derivative ethyl 5-(chloromethyl)furan-2-carboxylate undergoes two-electron electrochemical reduction in a simple, undivided cell to give the corresponding furylogous enolate anion, which can either be quenched with carbon dioxide to give a 5-(carboxymethyl)furan-2-carboxylate or with hydrogen ion to give a 5-methylfuran-2-carboxylate, thereby expanding the derivative scope of CMF as a biobased platform molecule.

5-(Chloromethyl)furfural (CMF) is a cellulose derivative of increasing appeal as a renewable platform molecule. Although its role as an electrophile has been broadly studied, little is known about ...

p-Type molecular dopants are a class of high electron affinity (EA) molecules used to ionize organic electronic materials for device applications. It is extremely challenging to ionize high-performance, high-ionization energy (IE) polymers because the dopant molecule needs to be compatible with solution processing. Here, we describe the synthesis and characterization of two new solution processable molecular dopants with the highest EA values yet reported. These molecules, based on the parent hexacyanotrimethylenecyclopropane (CN6-CP) structure, achieve solubility by the substitution of one or more of the cyano groups with esters, which both reduces the volatility relative to CN6-CP and allows for solution processing. The efficacy of these new molecular dopants, which have EA values up to 5.75 eV with respect to vacuum, was tested by performing sequential solution doping experiments with a series of thiophene and alternating diketopyrrolopyrrole polymers with IEs ranging from 5.10 eV to 5.63 eV. For completeness, the new dopant results are compared to a previously reported tri-ester substituted CN6-CP analogue with an EA of 5.50 EV. The increased EA of these stronger dopants induces a 10–100 fold increase in film conductivity and saturation of the conductivity at 15–100 S cm−1 for almost all polymers tested. These new dopant structures enable controlled solution doping at high doping levels for most alternating co-polymers of interest to the organic electronics community.

How well does the undergraduate organic chemistry laboratory curriculum prepare students for academic research, or for a bench job in industry? Running experiments that are more representative of research chemistry has the potential to better equip students for working in a research laboratory, while at the same time giving them insight into a typical outcome in a research project. We describe here an experiment that we have launched in the sophomore organic chemistry lab at UC Davis that presents challenges in chromatographic separation, structural assignment by NMR, and mechanistic interpretation. Optional exercises in computational modeling of the NMR data and chromophore analysis by UV–vis/fluorescence measurements are included.

Sequential solution doping is a processing technique that allows a conjugated polymer film to be doped from a solvent that will not dissolve the polymer. We present here a method to predict the film doping level in cm-3 from the solution concentration used to dope the film. We show using four polymers and three different and newly synthesized dopants that the doping level can me modeled using a simple Langmuir isotherm. In addition, analysis of the UV/vis spectra shows filling of the density of states. Polymers with a sharper band edge demonstrate much high conductivity for the same hole density. We analyze a series of DPP polymers and show how the polymer order changes as a function of the doping level. A second recent discovery is that the anion in sequentially doped films can be exchanged with another anion after doping. This means that the reactive molecule used to doped the polymer can be removed and replaced with a different ion that is not reactive. We present a multi-ion Langmuir isotherm model and show that the film doping level in mixed ion solutions can also be predicted.

Biobased 5-(chloromethyl)furoate and 5-methylfuroate esters can be deprotonated to function as furylogous lithium enolates, and the former can also undergo zinc insertion to access Reformatsky-type chemistry. Carbon nucleophilicity represents hitherto little-explored reactivity in these key carbohydrate-derived platform molecules, expanding their synthetic utility and potentially opening up new sustainable product markets (e. g., in epoxy resins or biobased dyes).

5-(Chloromethyl)furfural (CMF) is a carbohydrate-derived platform molecule that is gaining traction as a more practical alternative to 5-(hydroxymethyl)furfural (HMF). This perspective introduces the chemocatalytic approach to biorefining as the driving force behind the development of multifunctional chemical platforms. The main advantage of CMF over HMF is that it can be produced in high yield under mild conditions directly from raw biomass. Its stability and hydrophobicity markedly facilitate isolation. CMF is also a precursor to levulinic acid (LA), another versatile biobased intermediate. The logistics of CMF production are discussed, including reactor materials, HCl handling and management, byproducts, and the fate of collateral biomass components (hemicellulose, lipids, proteins, lignin). Examples of commercial markets that can be unlocked by synthetic manipulation of CMF are broken out into two derivative manifolds, furanic and levulinic, which are distributed over three product family trees: renew...

© 2019 American Chemical Society. Molecular dopants are increasingly studied to enhance the conductivity of semiconducting polymers. Most available p-type dopants have low solubility in common solvents and moderate electron affinities (EA), which makes solution processing difficult and limits the range of semiconducting polymers that can be doped. Here, we describe the synthesis and characterization of the new molecular dopant TMCN3-CP, which has an EA of 5.5 eV. We show that high ionization energy alternating copolymers such as PDPP-4T, PDPP-3T, and PDPP-T-TT-T can be p-type doped and achieve high conductivities with TMCN3-CP using sequential solution processing. The main advantage of this new dopant is the ability to chemically tailor the ester groups, which we demonstrate here for sequential solution doping of films. Sequential solution processing allows a greater ability to control the film morphology and is also desirable for scale-up to large-area polymer electronics.

The structural/geometrical features, multinuclear GIAO-NMR characteristics, tropicity, nucleus independent chemical shift NICS(1) and NICS(1)zz values, and NPA charge densities for phosphatriquinacene, its P-methylated phosphonium cation, the zwitterionic P-methylphosphaacepentalenide, and its conjugate acid have been modeled using DFT at the B3LYP/6-311++G(d,p) level of theory and are compared explicitly with computed data for the previously described aza-analogs at the same level of theory. By all investigated criteria, the phosphatriquinacene-based zwitterion is clearly aromatic but somewhat less so than the aza-analog. To probe the variations in anisotropic shielding effects, a number of other +P–R derivatives (R = H, F, CF3, iso-Pr, n-Pr, sec-Bu) were computed and compared with models. Extension of the study to the As-counterpart showed that by the same set of criteria, the arsa-bridged zwitterion is also aromatic. The relative aromaticity order in the main group family is N > P > As, which correlates with deviation from planarity of the annulene ring, as measured by the angle between the ring planes, i.e. (dr) N: 144.7°; P: 123.4°; As: 120.4°. Extension of the study to the dicationic group VI oxa- and thia-bridged analogs led to the same observation, i.e. relative aromaticity O > S. By contrast, an inverse correlation between planarity and aromaticity was found when comparing analogs from the same row of the periodic table, with relative aromaticity orders O > N and S > P. Including a solvation model (IEFPCM method) did not produce significant changes, although increasing solvent polarity led to slightly less negative NICS values and weaker anisotropic shielding.

High electron affinity (EA) molecules p-type dope low ionization energy (IE) polymers, resulting in an equilibrium doping level based on the energetic driving force (IE-EA), reorganization energy, and dopant concentration. Anion exchange doping (AED) is a process whereby the dopant anion is exchanged with a stable ion from an electrolyte. We show that the AED level can be predicted using an isotherm equilibrium model. The exchange of the dopant anion (FeCl3-) for a bis(trifluoromethanesulfonamide) (TFSI-) anion in the polymers poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly[3-(2,2-bithien-5-yl)-2,5-bis(2-hexyldecyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione-6,5-diyl] (PDPP-2T) highlights two cases in which the process is nonspontaneous and spontaneous, respectively. For P3HT, FeCl3 provides a high doping level but an unstable counterion, so exchange results in an air stable counterion with a marginal increase in doping. For PDPP-2T, FeCl3 is a weak dopant, but the exchange of FeCl3- for TFSI- is spontaneous, so the doping level increases by >10× with AED.

This chapter is a contemporary account of the platform molecules that constitute the fundamental building blocks of a future, biobased chemical industry. It compares and contrasts platform molecules and the current petrochemical base chemicals in terms of heteroatom content and chemical functionality. This approach highlights the extraordinary potential that biobased platforms offer the synthetic organic chemist and the biorefinery engineer. A demonstrative list of neoteric platform molecules is included to present a snapshot of the functional diversity available in these building blocks. The connection between the composition of the biomass feedstock and the associated processing technology is delineated, which gives an indication of which feedstocks and which platform molecules are most likely to contribute to sustainability purposes. Finally, the chapter concludes with a shortlist of 12 platform molecules that, in the authors' view, warrant particular attention from the research community in the coming years.

Cannabidiol (CBD) has proven clinical benefits in the treatment of seizures, inflammation, and pain. The recent legalization of CBD in many countries has caused increased interest in the drug as an over-the-counter treatment for athletes looking to improve recovery. However, no data on the effects of CBD on the adaptive response to exercise in muscle are available. To address this gap, we eccentrically loaded the tibialis anterior muscle of 14 rats, injected them with a vehicle (n = 7) or 100 mg/kg CBD (n = 7), and measured markers of injury, inflammation, anabolic signaling, and autophagy 18 hr later. Pro-inflammatory signaling through nuclear factor kappa B (NF-kB) (Ser536) increased with loading in both groups; however, the effect was significantly greater (36%) in the vehicle group (p p = .66). The ribosomal protein S6 phosphorylation (240/244) increased with stimulation (p p = .09). The ubiquitin-binding protein p62 levels were not modulated by stimulation (p = .6), but they were 46% greater in the CBD compared with the vehicle group (p = .01). Although liver weight did not differ between the groups (p = .99) and levels of proteins associated with stress were similar, we did observe serious side effects in one animal. In conclusion, an acute dose of CBD decreased pro-inflammatory signaling in the tibialis anterior without blunting the anabolic response to exercise in rats. Future research should determine whether these effects translate to improved recovery without altering adaptation in humans.

Furandioate-adipate copolyesters are an emerging class of bio-based biodegradable polymers with great potential to replace fossil-derived terephthalic acid-based copolyesters such as poly(butylene adipate-co-terephthalate) (PBAT). Furandioate-adipate polyesters have almost exclusively been prepared with conventional primary (1°) alcohol diols, while secondary (2°) alcohol diol monomers have largely been overlooked until now, despite preliminary observations that using methyl-branched diols increases the Tg of the resultant polyesters. Little is known of what impact the use of 2° alcohol diols has on other properties such as material strength, hydrophobicity, and rate of enzymatic hydrolysis—all key parameters for performance and end-of-life. To ascertain the effects of using 2° diols on the properties of furandioate-adipate copolyesters, a series of polymers from diethyl adipate (DEA) and 2,5-furandicarboxylic acid diethyl ester (FDEE) using different 1° and 2° alcohol diols was prepared. Longer transesterification times and greater excesses of diol (diol/diester molar ratio of 2:1) were found to be necessary to achieve Mws > 20 kDa using 2° alcohol diols. All copolyesters from 2° diols were entirely amorphous and exhibited higher Tgs than their linear equivalents from 1° diols. Compared to linear poly(1,4-butyleneadipate-co-1,4-butylenefurandioate), methyl-branched, poly(2,5-hexamethyleneadipate-co-2,5-hexamethylenefurandioate) (0:7:0.3 furandioate/adipate ratio) displayed both higher modulus (67.8 vs 19.1 MPa) and higher extension at break (89.7 vs 44.5 mm). All other methyl-branched copolyesters displayed lower modulus but retained higher extension at break compared with their linear analogues. Enzymatic hydrolysis studies using Humicola insolens cutinase revealed that copolyesters from 2° alcohol diols have significantly decreased rates of biodegradation than their linear equivalents synthesized using 1° alcohol diols, allowing for fine-tuning of polymer stability. Hydrophobicity, as revealed by water contact angles, was also found to generally increase through the introduction of methyl branching, demonstrating potential for these materials in coatings applications., Methyl branching in secondary diols has been found to increase the Tg, hydrophobicity, and resistance to biodegradation relative to linear diols for a family of bio-based copolyesters, providing a valuable tool to fine-tune material performance.

Molecular recognition is the key driver in the formation of supramolecular complexes, enabling the selective encapsulation of specific guests. Here, we explore the delicate balance between different energetic terms in the formation of an efficient host for fluoride anions based on a cylindrophane structure, which can be achieved by the incorporation of ligand sites into a cyanuric acid based cyclophane framework, resulting a close proximity between the ammonium hydrogens and the anion. This study describes the character and contribution of different energetic and repulsive terms that favor the efficient inclusion of fluoride. Our findings are useful for further rational design and synthesis of efficient and highly selective fluoride hosts, which have been generally less well described than complexing agents for other halides.

A new concept in anionic 10 π aromaticity is described by the embedding of a compensating charge within an aromatic cyclononatetraenide ring by the symmetric superposition of an alkyl ammonium bridge. This is accomplished by the methylation of azatriquinacene to give a quaternary ammonium salt, followed by oxidation to the tetraene and final deprotonation. The resulting zwitterion is a stable [9]annulene with strong aromaticity as shown by its degree of C-C bond equalization and a nucleus-independent chemical shift value lower than that of benzene. The solid-state structure shows an eclipsed stacking motif with the electron-poor ammonium methyl groups occupying the electron-rich cavity of the aromatic bowl.

The biomass-derived platform molecule levulinic acid is converted into the angelica lactone dimer (ALD) in high overall yield using simple inorganic catalysts. Hydrodecarboxylation of ALD using a Pd/γ-Al2O3 catalyst under moderate hydrogen gas pressure at high temperatures generates branched C8–C9 hydrocarbons in nearly quantitative yield by consuming as little as a single equivalent of external hydrogen. These molecules are high-octane “drop-in” equivalents of isoalkanes used in commercial gasoline. Catalytic hydrodecarboxylation is presented as a highly effective means to reduce hydrogen demand in biomass-to-biofuel conversion technologies.

The dye and pigment manufacturing industry is one of the most polluting in the world. Each year, over one million tons of petrochemical colorants are produced globally, the synthesis of which generates a large amount of waste. Naturally occurring, plant-based dyes, on the other hand, are resource intensive to produce (land, water, energy), and are generally less effective as colorants. Between these two extremes would be synthetic dyes that are fully sourced from biomass-derived intermediates. The present work describes the synthesis of such compounds, containing strong chromophores that lead to bright colors in the yellow to red region of the visible spectrum. The study was originally motivated by an early report of an unidentified halomethylfurfural derivative which resulted from hydrolysis in the presence of barium carbonate, now characterized as a butenolide of 5-(hydroxymethyl)furfural (HMF). The method has been generalized for the synthesis of dyes from other biobased platform molecules, and a mechanism is proposed.

There can be a fine line between therapeutic intervention and substance abuse, and this point is clearly exemplified in herbal cannabis and its products. Therapies involving cannabis have been the treatment of last resort for some cases of refractory epilepsy, and this has been among the strongest medical justifications for legalization of marijuana. In order to circumvent the narcotic effects of Δ9-tetrahydrocannabinol (THC), many studies have concentrated on its less intoxicating isomer cannabidiol (CBD). However, CBD, like all natural cannabinoids, is a controlled substance in most countries, and its conversion into THC can be easily performed using common chemicals. We describe here the anticonvulsant properties of 8,9-dihydrocannibidiol (H2CBD), a fully synthetic analogue of CBD that is prepared from inexpensive, non-cannabis derived precursors. H2CBD was found to have effectiveness comparable to CBD both for decreasing the number and reducing the severity of pentylenetetrazole-induced seizures in rats. Finally, H2CBD cannot be converted by any reasonable synthetic route into THC, and thus has the potential to act as a safe, noncontroversial drug for seizure mitigation.

There is a critical need to develop a method to pattern semiconducting polymers for device applications on the sub-micrometer scale. Dopant induced solubility control (DISC) patterning is a recently published method for patterning semiconductor polymers that has demonstrated sub-micron resolution. DISC relies on the sequential addition of molecular dopants (here 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ)) to the conjugated polymer. In doped areas, the conjugated polymer is protected from dissolution while in undoped areas, the polymer dissolves into solution. Here we examine factors that affect the resolution of the developed pattern. Two factors are determined to be critical to pattern resolution, the initial crystallinity of the polymer, here poly(3-hexylthiophene) (P3HT), and the quality of the development solvent. We find that dopants diffuse more readily in highly crystalline films than in amorphous films of P3HT and that dopant diffusion reduces the fidelity of the resulting pattern. We also find that the choice of development solvent affects both the fidelity of the pattern and dopant distribution within the patterned polymer domains. Finally, we show that a dopant that diffuses more slowly than F4TCNQ in the P3HT film can be used to pattern the film with higher fidelity. These results together provide a road map for optimizing additive DISC patterning for any polymer/dopant pair.

The crystal structures of the title compounds, C19H19NO and C31H34N2O, were determined as part of an experiment in an undergraduate teaching laboratory that demonstrates the relationship between molecular structure and function. 1′,3′,3′-Trimethylspiro[chromene-2,2′-indoline] is both a photoswitch and thermochromic molecule. Students synthesized it and a bis-indoline adduct and compared the crystallographically determined structures to computed gas-phase models.

© 2015 Elsevier Ltd. 5-(Chloromethyl)furfural (CMF) is rapidly being established as a renewable platform chemical of great promise. The effects of mass transfer, reaction temperature, Hansen solvent parameters, solvent fraction, and initial glucose concentrations on yields of CMF, 5-(hydroxymethyl)furfural (HMF), 2-(hydroxyacetyl)furan (HAF), levulinic acid (LA), and humic matter were investigated in a two-phase system of 6M HCl and an organic solvent. The ability of the solvent to extract HMF from the aqueous phase is found to be critical to achieving high CMF yields. Effective solvents must possess at least a small degree of Hansen hydrogen bonding capacity, and a high polarity is beneficial. Yields of CMF and HAF decrease with increasing glucose concentration but the yield of HMF is largely unaffected. The maximum productivity of CMF is achieved at a glucose loading of ca. 1.5M across all solvent fractions tested.

The gasoline market in the US is nearly twice that of diesel and jet fuel combined, and yet, nearly all research efforts to produce synthetic, biobased fuels center around these latter products. The reason for this is that a major component of gasoline is highly branched alkanes which, unlike straight chained products, are not readily derived from either fatty acid- or carbohydrate-based feedstocks. This review unpacks the motivations behind renewable gasoline synthesis and examines representative approaches to the targeted, de novo synthesis of densely-branched, high-octane isoalkanes and cycloalkanes employing chemocatalytic methods, as contrasted with the catalytic refining of biomass-derived feeds using petrochemical technologies.

5-(Chloromethyl)furfural (CMF) is a disruptive innovation in the biorefinery. Chemically, it is at least as versatile as the well-known HMF but, unlike HMF, it is accessible in high yield directly from cellulosic biomass due to its lipophilicity and stability under acidic conditions, which facilitate isolation. It has a rich derivative chemistry that includes biofuels, renewable polymers, specialty chemicals, and value-added agrochemical and pharmaceutical products.

An efficient synthetic approach to furan fatty acids starting from the biomass-derived platform chemical 5-(chloromethyl)furfural (CMF) is described. The route involves seven steps and has a 60% overall yield. Furan fatty acids are dietary antioxidants that occur naturally in fish and are proposed to have anti-atherosclerotic properties. The free radical scavenging abilities of synthetic furan fatty acids were evaluated against butylated hydroxytoluene (BHT) by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay.

A practical, scalable, metal-free synthesis of succinic acid from the biomass-derived platform chemical levulinic acid is described. Treatment of levulinic acid with the inexpensive, simple oxidant hydrogen peroxide under the catalytic action of trifluoroacetic acid gives succinic acid in high yield and enables facile product isolation by simple distillation of the volatile catalyst and byproducts.

A family of monomers, including 2,5-hexandiol, 2,7-octandiol, 2,5-furandicarboxylic acid (FDCA), terephthalic acid (TA), and branched-chain adipic and pimelic acid derivatives, all find a common derivation in the biomass-derived platform molecule 5-(chloromethyl)furfural (CMF). The diol monomers, previously little known to polymer chemistry, have been combined with FDCA and TA derivatives to produce a range of novel polyesters. It is shown that the use of secondary diols leads to polymers with higher glass transition temperatures (Tg) than those prepared from their primary diol equivalents. Two methods of polymerisation were investigated, the first employing activation of the aromatic diacids via the corresponding diacid chlorides and the second using a transesterification procedure. Longer chain diols were found to be more reactive than the shorter chain alternatives, generally giving rise to higher molecular weight polymers, an effect shown to be most pronounced when using the transesterification route. Finally, novel diesters with high degrees of branching in their hydrocarbon chains are introduced as potential monomers for possible low surface energy materials applications.

© 2016 American Chemical Society. Although doping is a cornerstone of the inorganic semiconductor industry, most devices using organic semiconductors (OSCs) make use of intrinsic (undoped) materials. Recent work on OSC doping has focused on the use of dopants to modify a material's physical properties, such as solubility, in addition to electronic and optical properties. However, if these effects are to be exploited in device manufacturing, a method for dedoping organic semiconductors is required. Here, we outline two chemical strategies for dedoping OSC films. In the first strategy, we use an electron donor (a tertiary amine) to act as competitive donor. This process is based on a thermodynamic equilibrium between ionization of the donor and OSC and results in only partial dedoping. In the second strategy, we use an electron donor that subsequently reacts with the p-type dopant to create a nondoping product molecule. Primary and secondary amines undergo a rapid addition reaction with the dopant molecule 2,3,5,6-tetrafluoro-7,7,8,8,-tetracyanoquinodimethane (F4TCNQ), with primary amines undergoing a further reaction eliminating HCN. Under optimized conditions, films of semiconducting polymer poly(3-hexylthiophene) (P3HT) dedoped with 1-propylamine (PA) reach as-cast fluorescence intensities within 5 s of exposure to the amine, eventually reaching 140% of the as-cast values. Field-effect mobilities similarly recover after dedoping. Quantitative fluorescence recovery is possible even in highly fluorescent polymers such as PFB, which are expected to be much more sensitive to residual dopants. Interestingly, treatment of undoped films with PA also yields increased fluorescence intensity and a reduction in conductivity of at least 2 orders of magnitude. These results indicate that the process quantitatively removes not only F4TCNQ but also intrinsic p-type impurities present in as-cast films. The dedoping strategies outlined in this article are generally applicable to other p- and n-type molecular dopants in OSC films.

5-(Halomethyl)furfurals (XMFs) are biomass-derived platform chemicals that are gaining traction as practical alternatives to 5-(hydroxymethyl)furfural (HMF). This chapter provides an overview of the historical role of XMFs in the chemical investigation of carbohydrates and describes multiple approaches to their preparation, including recent breakthroughs by which XMFs, and in particular 5-(chloromethyl)furfural (CMF), are obtained in high yield directly from raw biomass. Halomethylfurfurals have two basic derivative manifolds: furanic and levulinic, and this chapter will highlight commercial markets that can be unlocked by synthetic manipulation of CMF and its immediate derivatives.

Prothrin, a synthetic pyrethroid insecticide, was synthesized from the biomass-derived platform chemical 5-(chloromethyl)furfural in six steps and overall 65% yield. Two structural analogues of prothrin were also prepared following the same synthetic approach. Preliminary testing of these furan-based pyrethroids against the yellow fever mosquito Aedes aegypti indicates promising insecticidal activities.

3-Hydroxypropanoic acid (HPA), a precursor to acrylic acid, can be produced in high yield by oxidation of the biomass-derived platform chemical levulinic acid. While treatment of levulinic acid with H2 O2 under acidic conditions gives predominantly succinic acid, a remarkable reversal of selectivity is observed under basic conditions, leading either directly to HPA or, under modified conditions, initially to 3-(hydroperoxy)propanoic acid, which can be quantitatively hydrogenated to HPA.

Acid chloride derivatives of 5-(chloromethyl)furan-2-carboxylic acid and furan-2,5-dicarboxylic acid (FDCA) can be produced in high yield by treatment of the precursor aldehydes 5-(chloromethyl) furfural (CMF) and 2,5-diformylfuran (DFF) with tert-butyl hypochlorite, which is inexpensively prepared from commercial bleach and tert-butanol. 5-(Chloromethyl)furan-2-carbonyl chloride (CMFCC) and furan-2,5-dicarbonyl chloride (FDCC) are highly useful intermediates for the production of furoate ester biofuels and polymers of FDCA.

The first stable α-oxyoxonium species have been synthesized and characterized. Strong donation of nonbonding electrons on oxygen into the adjacent σ*(C-O(+)) orbital was predicted by modeling to result in unheard of carbon-oxygen bond lengths. The kinetic stability of the triquinane ring system provides a platform upon which to study these otherwise elusive species, which are evocative of intermediates on the acetalization reaction pathway. Crystallographic analysis of the α-hydroxy and α-methoxy oxatriquinane triflates reveals 1.658 and 1.619 Å C-O(+) bond lengths, respectively, the former of which is a new record for the C-O bond.

The crystal structures of the title compounds were determined as part of an experiment in an undergraduate teaching laboratory that demonstrates the relationship between mol­ecular structure and function. 1′,3′,3′-Tri­methyl­spiro­[chromene-2,2′-indoline] is both a photoswitch and thermochromic mol­ecule. Students synthesized it and a bis-indoline adduct and compared the crystallographically determined structures to computed gas-phase models., The crystal structures of the title compounds, C19H19NO and C31H34N2O, were determined as part of an experiment in an undergraduate teaching laboratory that demonstrates the relationship between mol­ecular structure and function. 1′,3′,3′-Tri­methyl­spiro­[chromene-2,2′-indoline] is both a photoswitch and thermochromic mol­ecule. Students synthesized it and a bis-indoline adduct and compared the crystallographically determined structures to computed gas-phase models.

© The Royal Society of Chemistry 2016. Doping polymeric semiconductors often drastically reduces the solubility of the polymer, leading to difficulties in processing doped films. Here, we compare optical, electrical, and morphological properties of P3HT films doped with F4TCNQ, both from mixed solutions and using sequential solution processing with orthogonal solvents. We demonstrate that sequential doping occurs rapidly (

This review provides a technical description of the range of commercial products that can be accessed from n-butanol, with specific emphasis on n-butanol derived from renewable sources (biobutanol). n-Butanol itself and primary derivatives in which the oxygen functionality of the molecule is retained (butyraldehyde and butyric acid) have mainstream applications in the solvent, polymer, fuel oxygenate, and/or specialty chemical markets, while butanol dehydration products (butenes and butadiene) present additional opportunities in the hydrocarbon fuel and synthetic elastomers markets. The volume and value of these markets are noted and specific applications of first- and second-generation n-butanol derivatives are discussed. Selected technologies for the conversion of butenes into other valuable olefins are described and current biobutanol producers and technology providers are identified and profiled. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd