The low-temperature solubility of aniline, the toluidines and some of their N-alkyl derivatives in aviation gasoline
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ANTIKNOCK COMPOUNDS - ANILINE↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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End of Project Report [Upgrading measurement capabilities for hydrocarbons, halocarbons and alkyl nitrates]
This paper presents the End of Project Report from the P3-B Christmas Island local flights. Altitudinal variations in mixing ratios of several marine emitted gases, including DMS (dimethyl sulfide) are illustrated. This paper is presented in viewgraph form.
Blake, Donald R.↗
Carbon and nitrogen isotopic compositions of alkyl porphyrins from the Triassic Serpiano oil shale
The carbon and nitrogen isotopic compositions of seven of the most abundant alkylporphyrins from the Serpiano oil shale (marine, Triassic) were determined. For the C31 and C32 butanoporphyrins, values of delta 13CPDB and delta 15NAIR averaged -24.0% and -3.1%. In contrast, the C31 and C32 methylpropanoporphyrins, DPEP, and a C30 13-nor etioporphyrin had delta 13C and delta 15N values averaging -27.5 and -3.3%, respectively. Carbon and nitrogen isotopic values for kerogen averaged -30.8 and -0.9, whereas those for total extract averaged -31.6, and -4.0%. The butanoporphyrins apparently derive from a biological source different from that giving rise to the other porphyrins, their 13C enrichment not being related to carbon isotopic fractionation accompanying diagenetic reactions. The delta 15N values for all the porphyrins indicate that the depletion of 15N observed in the kerogen is of primary origin. Consistent with the very high abundance of hopanoids and methyl hopanoids in the aliphatic hydrocarbon fraction, it is suggested that cyanobacterial fixation of N2 may have been the main cause of 15N depletion.
NASA Discipline Exobiology↗
Perfluorinated Alkyl Acids in Plasma of American Alligators (Alligator Mississippiensis) from Florida and South Carolina
This study aimed to quantitate fourteen perfluoroalkyl acids (PFAAs) in 125 adult American alligators at twelve sites across the southeastern US. Of those fourteen PFAAs, nine were detected in 65% - 100% of the samples: PFOA, PFNA, PFDA, PFUnA, PFDoA, PFTriA, PFTA, PFHxS, and PFOS. Males (across all sites) showed significantly higher concentrations of four PFAAs: PFOS (p = 0.01), PFDA (p = 0.0003), PFUnA (p = 0.021), and PFTriA (p = 0.021). Concentrations of PFOS, PFHxS, and PFDA in plasma were significantly different among the sites in each sex. Alligators at Merritt Island National Wildlife Refuge and Kiawah Nature Conservancy both exhibited some of the highest PFOS concentrations (medians 99.5 ng/g and 55.8 ng/g respectively) in plasma measured to date in a crocodilian species. A number of positive correlations between PFAAs and snout-vent length (SVL) were observed in both sexes suggesting PFAA body burdens increase with increasing size. In addition, several significant correlations among PFAAs in alligator plasma may suggest conserved sources of PFAAs at each site throughout the greater study area. This study is the first to report PFAAs in American alligators, reveals potential PFAA hot spots in Florida and South Carolina, and provides and additional contaminant of concern when assessing anthropogenic impacts on ecosystem health.
crocodilians↗
Perfluorinated Alkyl Acids and Fecundity Assessment in Striped Mullet (Mugil Cephalus) at Merritt Island National Wildlife Refuge
This study investigated wild caught Striped mullet (Mugil cephalus) at Merritt Island National Wildlife Refuge (MINWR) for levels of 15 perfluoroalkyl acids (PFAAs) in tandem with fecundity measurements (n 42) and oocyte developmental stages (n 128). PFAAs measurements were undertaken for liver (n 128), muscle (n 49), and gonad (n 10). No significant negative impacts of liver PFAA burden on wild-caught, mullet fecundity endpoints are observed in this study; however, changes in PFAAs are seen in the liver as mullet progress through different sub-stages of oocyte development. Of the PFAAs with significant changes by sub-stage of oocyte development, the carboxylic acids (perfluorooctanoic acid, perfluorononanoic acid, and perfluorotridecanoic acid) increase in the liver with increasing sub-stage while the sulfonic acid and its precursor (perfluorooctanesulfonic acid (PFOS) and perfluorooctanesulfonamide, respectively) decrease in the liver with increasing stage of oocyte development. This is a unique find and suggests PFAAs change location of compartmentalization as mullet progress towards spawning. Investigations also revealed higher than expected median muscle and gonad levels of PFOS in Striped mullet collected at MINWR (9.01 ngg and 80.2 ngg, respectively).
Jacqueline T Bangma↗
Alkyl Amine Incorporation in Functional and Processible Porous Organic Polymers for CO2 Capture Applications
2022 AIChE Annual Meeting, Phoenix, AZ, November 13-18, 2022
Sekizkardes, Ali↗
Impact of Alkyl Chain Length on Low-Temperature Oxidation of Methyl, Ethyl, and Propyl Cyclohexanes
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Chemistry↗
Fuel Properties of Oxymethylene Ethers with Terminating Groups from Methyl to Butyl
Oxymethylene ethers (OMEs) have been studied as possible additives or replacements for diesel fuels. Typically, studies have considered only methyl-terminated OMEs. Recent structure-property relationship models suggest that extended-alkyl OMEs may provide improvements to many of the properties of methyl-terminated OMEs that make them less suitable as diesel fuel blendstocks. In this work, we describe the synthesis and characterization of 16 different OMEs with methyl, ethyl, propyl, butyl, isopropyl, and isobutyl terminating alkyl groups with varying oxymethylene chain length. Indicated Cetane Number, Lower Heating Value, Flash Point, Density, Viscosity, Vapor Pressure, and Oxidative Stability are tested via ASTM standard methods. Additionally, Water Solubility, Boiling Point, seal material compatibility, and sooting propensity (via the Yield Sooting Index) are measured for these fuels. For diesel compatibility, all tested OMEs except smaller methyl and ethyl OMEs, and the branched isopropyl OME, meet cetane number requirements. Further, extending the alkyl end group increases the heating value, but all OMEs, due to their oxygen content, have heating values less than diesel; despite this, all OMEs show significant reductions in soot production per unit heating value. Only the heaviest OMEs meet diesel viscosity requirements, and most are higher density than diesel. OMEs with larger alkyl groups show the highest stability under accelerated auto-oxidation conditions. Increases in alkyl group length cause order of magnitude reduction in water solubility, from hundreds of g/L for methyl terminated OMEs to hundreds of mg/L for butyl terminated OMEs. Limited seal material testing indicates that PEEK polymers are unaffected by OMEs; while extended alkyl groups may improve compatibility with FKM (Viton), other common elastomers (NBR, silicone) remain incompatible with all tested OMEs. Overall, it is found that methyl-terminated OMEs exhibit the most potential for soot reduction, but OMEs with larger propyl and butyl terminating alkyl groups show improved compatibility with existing diesel systems.
09 BIOMASS FUELS↗
Solvent for non-aqueous battery
A solvent useful for lithium batteries comprises a compound of Formula (I): (R1)(R2)(R3)Si—R4—O—C(O)—[(O—R5)n—(O—C(O)]m—O—R6—X1. Each of R1 and R2 independently is alkyl; R3 is alkyl, —X2—Si(R7)(R8)(R9), or —CH2—O—C(O)—O—R10; X1 is H or —Si(R11)(R12)(R13); each of R4 and R6 independently is alkylene; each R5 independently is C2 to C6 alkylene; each of R7, R8, R9, and R10 independently is alkyl; X2 is O or alkylene; each of R11 and R12 independently is alkyl; R13 is alkyl or —X3—Si(R14)(R15)(R16); each of R14, R15, and R16 independently is alkyl; X3 is O or alkylene; m is 0 or 1, and n is 1-3; and when m is 0 and R3 is alkyl, X1 is —Si(R11)(R12)(R13). Also described is a method for manufacturing a compound of Formula (II): (R17)(R18)(R19)Si—CH2—O—C(O)—O—R20 where each R17, R18, R19, and R20 is alkyl.
25 ENERGY STORAGE↗
The effects of organosulfur compounds upon the storage stability of Jet A fuel
This study examined the effect of sulfur-containing compounds on the storage stability of Jet A turbine fuel. It was found that alkyl sulfides and disulfides increased the fuel's stability while all thiols and thiophene derivatives tested decreased fuel stability (increased deposit formation) at temperatures and sulfur concentrations selected. Linear Arrhenius plots of sulfur-spiked fuel samples demonstrated that deposit formation decreased with increased slope for all alkyl sulfides, alkyl disulfides, thiols, and thiophene derivatives. A plot of insoluble deposit vs. concentration of added alkyl sulfide produces a negative slope. It appears that the inhibiting mechanism for alkyl sulfides is a result of the compound's reactivity with intermediate soluble precursors to deposit in the fuel. A method of approximating the relative basicity of weak organosulfur bases was developed via measurement of their resonance chemical shifts in proton NMR. Linear plots of log gm. deposit vs. change in chemical shift (shift differences between sulfur bases neat and complexed with I2) were found for alkyl sulfides and alkyl thiols. This suggests the possibility that increased deposit formation is due to base catalysis with these compound classes.
Heneman, F. C.↗
Multi-layered perovskites, devices, and methods of making the same
Methods are described that include contacting an alkyl ammonium metal halide film with an alkyl ammonium halide, where the alkyl ammonium metal halide film includes a first halogen and a metal, the alkyl ammonium halide includes a second halogen, such that the contacting forms an alkyl ammonium metal mixed-halide film that interfaces with the alkyl ammonium metal halide film, where the alkyl ammonium metal mixed-halide film includes the first halogen, the second halogen, and the metal.
14 SOLAR ENERGY↗
Multi-layered perovskites, devices, and methods of making the same
Methods are described that include contacting an alkyl ammonium metal halide film with an alkyl ammonium halide, where the alkyl ammonium metal halide film includes a first halogen and a metal, the alkyl ammonium halide includes a second halogen, such that the contacting forms an alkyl ammonium metal mixed-halide film that interfaces with the alkyl ammonium metal halide film, where the alkyl ammonium metal mixed-halide film includes the first halogen, the second halogen, and the metal.
Zhu, Kai↗
Development, Application, and Mechanistic Interrogation of a Dual Ni Catalysis Approach to Photoredox-Based C(sp 3 )–C(sp 3 ) Cross-Coupling
The installation of alkyl substituents such as methyl groups is a crucial tactic for the synthesis and diversification of medicinal compounds with improved pharmacological profiles. However, strategies that leverage methyl radical for C(sp 3 ) methylation remain underdeveloped due to the challenge of obtaining cross-selectivity between fleeting aliphatic radicals and alkyl electrophiles. Here, we report the development, application, and interrogation of a conceptually novel mechanistic framework for C(sp 3 )–Me bond formation using two distinct Ni catalysts capable of cross-coupling sterically and electronically diverse alkyl halides (chlorides and bromides) with methyl radical generated photocatalytically from benzaldehyde dimethyl acetal. Furthermore, by modifying the alkyl substituents on the acetal coupling partner, we demonstrate cross-couplings beyond methylation to access an array of 1°–1° and 1°–2° alkyl–alkyl bonds. Experimental and computational mechanistic studies provide support for cooperativity between an in situ-generated (bpy)Ni I (X) catalyst that facilitates XAT and inner-sphere C–C bond formation and a (Tp*)Ni II (acac) cocatalyst that captures methyl radical and engages in concurrent outer-sphere S H 2 coupling.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Pyrolysis of bio-derived dioxolane fuels: A ReaxFF molecular dynamics study
Alkyl-substituted 1,3-dioxolanes, including 4,5-dimethyl-2-pentan-3-yl-1,3-dioxolane (Fuel 1), 4,5-dimethyl-2-pentyl-1,3-dioxolane (Fuel 2), and 2-(heptan-3-yl)-4,5-dimethyl-1,3-dioxolane (Fuel 3), have been recently suggested as potential biodiesels. In this paper, we investigate the initial pyrolysis of the alkyl-substituted 1,3-dioxolanes at high temperatures using ReaxFF molecular dynamics (MD) simulations. We analyze the decomposition rate, reaction mechanism, and product distribution in the pyrolysis of the three alkyl 1,3-dioxlanes. The three fuels primarily decompose to 4,5-dimethyl-1,3-dioxolane radical and hydrocarbons derived from the alkyl side-chains. The further decomposition of 4,5-dimethyl-1,3-dioxolane radical primarily leads to 2-C 4 H 8 and CO 2 within a few decomposition steps. The hydrocarbon product distribution is significantly affected by the molecular structure of the alkyl side-chain, which would have a strong influence on the sooting tendency of these fuels. The ReaxFF simulations predict that the order of sooting tendency would be Fuel 3 > Fuel 1 > Fuel 2, which agrees with the measured sooting tendency trend. Based on the pyrolysis mechanism identified by ReaxFF, we propose a new alkyl dioxolane, 4-hexyl-5-methyl-1,3-dioxolane (Fuel 4), which might produce even less soot, by modifying the molecular structure of Fuel 2. Our ReaxFF simulation shows that Fuel 4 produce much less C 4 H 8 , an effective non-aromatic soot precursor, than Fuel 2. Moreover, more carbon atoms are bonded to each oxygen atom in Fuel 4 than Fuel 2, which would help reduce soot yield by removing more carbon atoms from the soot-producing pool of species. The major decomposition pathways identified in this work can be used to develop chemical kinetic models for 1,3-dioxolane based compounds, as biodiesel components, applicable to combustion engine simulations. We also demonstrate that the chemical kinetic insight offered by ReaxFF simulations can be used to design new fuel molecules with more desired properties.
09 BIOMASS FUELS↗
Dyes, dye-sensitized solar cells, and methods of making and using the same
Provided herein are dyes, dye-sensitized solar cells, and sequential series multijunction dye-sensitized solar cell devices. The dyes include an electron deficient acceptor moiety, a medium electron density π-bridge moiety, and an electron rich donor moiety comprising a biaryl, a substituted biaryl, or an R 1 , R 2 , R 3 substituted phenyl where each of R 1 , R 2 , and R 3 independently comprises H, aryl, multiaryl, alkyl substituted aryl, alkoxy substituted aryl, alkyl substituted multiaryl, alkoxy substituted multiaryl, OR 4 , N(R 5 ) 2 , or a combination thereof; each R 4 independently comprises H, alkyl, aryl, alkyl substituted aryl, alkoxy substituted aryl, or a combination thereof; and each R 5 independently comprises aryl, multiaryl, alkyl substituted aryl, alkoxy substituted aryl, alkyl substituted multiaryl, alkoxy substituted multiaryl, or a combination thereof. The solar cells include a glass substrate, a dye-sensitized active layer, and a redox shuttle. The devices include at least two dye-sensitized solar cells connected in series.
Delcamp, Jared Heath↗
Copper‐Catalyzed C(sp 3 )−H α‐Acetylation: Generation of Quaternary Centers
Abstract α‐substituted ketones are important chemical targets as synthetic intermediates as well as functionalities in natural products and pharmaceuticals. We report the α‐acetylation of C(sp 3 )−H substrates R−H with arylmethyl ketones ArC(O)Me to provide α‐alkylated ketones ArC(O)CH 2 R at RT with t BuOO t Bu as oxidant via copper(I) ‐diketiminato catalysts. Proceeding via alkyl radicals R•, this method enables α‐substitution with bulky substituents without competing elimination that occurs in more traditional alkylation reactions between enolates and alkyl electrophiles. DFT studies suggest the intermediacy of copper(II) enolates [Cu II ](CH 2 C(O)Ar) that capture alkyl radicals R• to give R−CH 2 C(O)Ar outcompeting dimerization of the copper(II) enolate to give the 1,4‐diketone ArC(O)CH 2 CH 2 C(O)Ar.
Okoromoba, Otome E.↗
Copper‐Catalyzed C(sp 3 )−H α‐Acetylation: Generation of Quaternary Centers
Abstract α‐substituted ketones are important chemical targets as synthetic intermediates as well as functionalities in natural products and pharmaceuticals. We report the α‐acetylation of C(sp 3 )−H substrates R−H with arylmethyl ketones ArC(O)Me to provide α‐alkylated ketones ArC(O)CH 2 R at RT with t BuOO t Bu as oxidant via copper(I) ‐diketiminato catalysts. Proceeding via alkyl radicals R•, this method enables α‐substitution with bulky substituents without competing elimination that occurs in more traditional alkylation reactions between enolates and alkyl electrophiles. DFT studies suggest the intermediacy of copper(II) enolates [Cu II ](CH 2 C(O)Ar) that capture alkyl radicals R• to give R−CH 2 C(O)Ar outcompeting dimerization of the copper(II) enolate to give the 1,4‐diketone ArC(O)CH 2 CH 2 C(O)Ar.
Okoromoba, Otome E.↗
Rapid Postgrafting Reaction to Prepare Quaternized Polycarbazoles
We report a rapid postgrafting reaction to prepare alkyl ammonium functionalized polycarbazoles from a commercially available monomer. This novel synthetic approach provides benefit to preparing the high molecular weight quaternized polycarbazoles within 1 h of Friedel–Crafts polycondensation, avoiding the synthesis and purification step to prepare a functionalized monomer. The postgrafting reaction produces hexyl alkyl ammonium functionalized polycarbazole with 100% grafting degree. However, the postgrafting reaction produced only 60% grafting with propyl alkyl ammonium due to the competitive elimination reaction because of the higher acidity of β-hydrogen in the propyl alkyl group resulting from the proximity of the bromide and ammonium groups. The hexyl alkyl ammonium functionalized polycarbazole has a high hydroxide conductivity of 103 mS cm –1 at 80 °C and showed excellent alkaline stability with less than 3% loss of ion group after 1 M NaOH treatment at 80 °C for 500 h. In conclusion, this study highlights that the postgrafting reaction provides a pathway for the scale-up synthesis of quaternized aryl ether-free polyaromatics.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗