Acetic Anhydride and Mixed Fatty Acid Anhydrides

Held, Heimo; Rengstl, Alfred; Mayer, Dieter

doi:10.1002/14356007.a01_065

Cited by 13 publications

(20 citation statements)

References 41 publications

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“…The importance of strong acids and bases is notorious at the beginning of the 19th century, which gradually winds down, giving place to more organic chemistry-oriented substrates. A remarkable substrate is acetic anhydride; predicted theoretically in 1851, synthesized the next year (7), becoming the fifth most used substrate by 1880-1889 and the top substrate since 1940-1959, it is mainly used in acetylation reactions (17). Methyl iodide, which often appears among the top 10, is an important methylating agent (18).…”

Section: Historical Trends For Substrates and Products In The Exploramentioning

confidence: 99%

Exploration of the chemical space and its three historical regimes

Llanos

Leal

Luu

et al. 2019

Proc. Natl. Acad. Sci. U.S.A.

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Chemical research unveils the structure of chemical space, spanned by all chemical species, as documented in more than 200 y of scientific literature, now available in electronic databases. Very little is known, however, about the large-scale patterns of this exploration. Here we show, by analyzing millions of reactions stored in the Reaxys database, that chemists have reported new compounds in an exponential fashion from 1800 to 2015 with a stable 4.4% annual growth rate, in the long run neither affected by World Wars nor affected by the introduction of new theories. Contrary to general belief, synthesis has been the means to provide new compounds since the early 19th century, well before Wöhler's synthesis of urea. The exploration of chemical space has followed three statistically distinguishable regimes. The first one included uncertain year-to-year output of organic and inorganic compounds and ended about 1860, when structural theory gave way to a century of more regular and guided production, the organic regime. The current organometallic regime is the most regular one. Analyzing the details of the synthesis process, we found that chemists have had preferences in the selection of substrates and we identified the workings of such a selection. Regarding reaction products, the discovery of new compounds has been dominated by very few elemental compositions. We anticipate that the present work serves as a starting point for more sophisticated and detailed studies of the history of chemistry.history of chemistry | chemical space | chemical reactions | World War | structural theory

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Section: Historical Trends For Substrates and Products In The Exploramentioning

confidence: 99%

Exploration of the chemical space and its three historical regimes

Llanos

Leal

Luu

et al. 2019

Proc. Natl. Acad. Sci. U.S.A.

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“…3) Anhydrides consist of two acyl groups (RCO-, carbonyl and alkyl groups) connected to the oxygen atom in the acid anhydrides [24]. It is also a reactive acyl group, so it can produce carboxylic acid and acetate esters [27]. 4)…”

Section: Chemistry Of Carbonyl Groupsmentioning

confidence: 99%

Chemo-physical analysis and molecular dynamics (MD) simulation of moisture susceptibility of nano hydrated lime modified asphalt mixtures

Yao

Dai

You

2015

Construction and Building Materials

103

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The purpose of this study is to investigate the moisture susceptibility of nano hydrated lime (NHL) modified asphalt mixtures and determine the fundamental factors of moisture damage in asphalt mixtures using the molecular dynamics (MD), as well as analyze the effect that the aging of asphalt binders has on the moisture damage in asphalt mixtures. The NHL was added to the control asphalt to make NHL modified asphalt. The modified asphalt was mixed with aggregates to form NHL modified asphalt mixtures. The tensile strength ratio (TSR) test was used to evaluate the moisture susceptibility of asphalt mixtures. When the TSR test was done, different solutions were used to extract the polar groups from the tested asphalt mixtures, and the polar groups were analyzed using Fourier transform infrared spectroscopy (FTIR) attenuated total reflection (ATR). When asphalt oxidizes, the six functional groups (ketones, carboxylic acids, anhydrides, aldehydes, amides and esters) with the carbonyl group can be found in the polar part of asphalt based on FTIR ATR spectral data and references. The polar groups with the carbonyl group also indicate the oxidation extent of asphalt binders. The FTIR test results indicate that carboxylic acids and ketones were the primary aging products in asphalt, and these two carbonyl groups relate to the rutting resistance and moisture susceptibility of asphalt mixtures. Furthermore, the MD interface systems of asphalt-aggregate and aggregatewater were created, as well as the separated systems (asphalt, water, and aggregates). The essential mechanisms for the moisture susceptibility of asphalt mixtures were explored with MD simulations. The potential energies of the interface systems and each separated system were computed to obtain the adhesion energies of the interface MD models. The differences in adhesion energy between the asphalt-aggregate and aggregate-water systems show that water tends to bond to the aggregate rather than the asphalt. This also explains the displacement of water that occurs in asphalt mixtures when there is moisture damage. In addition, the effect of 3 asphalt aging on the moisture susceptibility of the asphalt mixture was also analyzed using MD interface models. The MD results demonstrate that the aging group in asphalt is helpful in reducing the moisture damage in asphalt mixtures.

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“…The worldwide production of acetic anhydride is a further major application and uses approximately 25-30 % of the global production of acetic acid. The main process involves dehydration of acetic acid to give ketene at the temperature of 700-750 C. Ketene is thereafter reacted with acetic acid to obtain the anhydride (Held et al 2005). Acetic anhydride is an acetylation agent.…”

Section: Sequence Chemical Products and Applications From Organic Acidsmentioning

confidence: 99%

Microbial Life on Green Biomass and Their Use for Production of Platform Chemicals

Schönicke

Shahab

Hamann

et al. 2014

Microorganisms in Biorefineries

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Acetic Anhydride and Mixed Fatty Acid Anhydrides

Abstract: The article contains sections titled: 1. Acetic Anhydride 1.1. Physical Properties … Show more

Cited by 13 publications

References 41 publications

Exploration of the chemical space and its three historical regimes

Exploration of the chemical space and its three historical regimes

Chemo-physical analysis and molecular dynamics (MD) simulation of moisture susceptibility of nano hydrated lime modified asphalt mixtures

Microbial Life on Green Biomass and Their Use for Production of Platform Chemicals

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