Thermodynamic Properties and Ideal-Gas Enthalpies of Formation for Butyl Vinyl Ether, 1,2-Dimethoxyethane, Methyl Glycolate, Bicyclo[2.2.1]hept-2-ene, 5-Vinylbicyclo[2.2.1]hept-2-ene, <i>trans</i>-Azobenzene, Butyl Acrylate, Di-<i>tert</i>-butyl Ether, and Hexane-1,6-diol

Steele, W.V.; Chirico, Robert D.; Knipmeyer, S.E.; Nguyen, A.; Smith, N. K.

doi:10.1021/je960117w

Cited by 97 publications

(73 citation statements)

References 69 publications

(98 reference statements)

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“…Our experimental values were compared to standard Gibbs free energies and enthalpies of reaction (subscript Δ r-f X°) calculated via energies of formation of the relevant components in the gas phase (Δ f G°, Δ f H°) as found in databases or publications (see Table S2). [31,32] The thus calculated Δ r-f H°value of 89.3 kJ mol À 1 is in good agreement with our experimental measurements, while the Δ r-f G°of 70.9 kJ mol À 1 is a bit off (vs. extrapolated 49.2 kJ mol À 1 ). This can either be due to inaccuracies in database computational values for Δ f G°of specific compounds (notably, for MGA, experimentally verified data is lacking), or, due to errors in our assumptions, i. e. the standard entropy of reaction being constant in function of T and/or the exclusion of ca.…”

Section: Resultssupporting

confidence: 81%

Catalytic Gas‐Phase Cyclization of Glycolate Esters: A Novel Route Toward Glycolide‐Based Bioplastics

et al. 2018

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A catalytic process to produce glycolide, the cyclic dimer of glycolic acid (GA), is proposed. Glycolide is the key building block of the biodegradable plastic polyglycolic acid. Instead of the current industrial two‐step route, which involves the polycondensation of GA and a subsequent backbiting reaction, a new route based on the gas‐phase transesterification of methyl glycolate (MGA) over a fixed catalyst bed is presented. With specific supported TiO2 catalysts, a high glycolide selectivity of 75–78 % can be achieved at the thermodynamically‐limited equilibrium conversion of MGA (54 % at 300 °C, 5.6 vol% MGA, 1 atm). The absence of solvent and the continuous nature of the process should allow for easy product separation and recycling of unconverted esters, while the few side‐products, i. e. linear alkyl glycolate dimers and trimers seem recoverable via methanolysis. The reaction is compared to the cyclization of other α‐hydroxy esters, such as methyl lactate to lactide, over the same catalysts, in terms of kinetics and thermodynamics. The absence of a methyl substitution on the α‐carbon seems to lead to faster cyclization kinetics of MGA when compared to methyl lactate or the double‐substituted methyl‐2‐hydroxy‐isobutyrate. Contrarily, glycolide production is less favored thermodynamically compared to lactide. The absence of glycolide decomposition at temperatures up to 300 °C however allows to increase equilibrium conversion by taking the endergonic reaction to higher temperatures.

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Section: Resultssupporting

confidence: 81%

Catalytic Gas‐Phase Cyclization of Glycolate Esters: A Novel Route Toward Glycolide‐Based Bioplastics

et al. 2018

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“…[29] and [30], and a value of 345 kJ/mol for liquid phenyl azide from Ref. [31] we find this reaction is exothermic by ca.…”

mentioning

confidence: 68%

Paradigms and paradoxes: organic thermochemistry without hydrogen: carbon oxides and nitrides

Slayden

Liebman

2008

Struct Chem

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All organic compounds contain carbon. Most contain hydrogen. This brief study discusses the enthalpy of formation of a collection of organic compounds containing only oxygen or nitrogen accompanying the carbon.By definition, organic chemistry is the chemistry of carboncontaining compounds. Almost always, in practice organic chemistry is also the chemistry of compounds containing hydrogen. Relatedly, organic thermochemistry discusses the thermochemistry of carbon-, and most often, hydrogen-, containing species. There are several thousand organic species for which the enthalpies of formation is known. In the current note we discuss the enthalpies of formation of those species that lack hydrogen, in particular, carbon oxides and carbon nitrides but not halocarbons. The current study will be limited to those species for which these data are found from experiment, whether or not the species be isolable. We will also limit our attention to neutral species and so ignore all ions such as the commonplace CN -and rather exotic CN + . We proceed first through the oxides and then the nitrides of carbon. Within each group, the compounds are discussed in order of increasing number of carbons, and then by increasing number of oxygens or nitrogens. All unreferenced enthalpies of formation in the current study are taken from Ref.[1] and may tacitly be assumed to refer to gaseous species at 298 K and 1 atm unless otherwise said.While there are a respectable number of species containing only carbon and oxygen, there are only three isolable compounds for which enthalpy of formation data are available: carbon monoxide (CO), carbon dioxide (CO 2 ) and propadienedione (C 3 O 2 ), the so-called carbon suboxide. Not limiting our species of interest by grounds of isolability allows us to consider other oxides of carbon, CO 3 , C 2 O, and C 3 O.Enthalpies of formation of CO and CO 2 are found from numerous sources. We choose the values -110.525 and -393.509 kJ/mol [2]. These values are well-established, the latter providing a benchmark value for the enthalpies of formation and combustion of nearly all organic compounds. Perhaps the only thermochemical observation of consequence we will make in this study relates to their carbon-oxygen bond energies. The ratio of the C-O bond energy in CO 2 to that of (the mean) value for CO is very nearly the same as the ratio for the Si-O bond energies in SiO 2 and gaseous SiO despite the fact that CO 2 is ''naturally'' a gas while SiO 2 is ''naturally'' a solid. Perhaps this is not so strange: this near constant ratio in the gas phase for some other pairs of species containing group 14-16 atoms was first pointed out in Ref. [3], and extended by consideration of experimentally unexplored neutrals [4] as well as valence isoelectronic pairs of cations [5], anions [5], and some hydrogen-containing pentatomics as well [6]. Summarizing, for 10 valence electron AB and 16 valence electron AB 2 , we findThis is a comfortably simple approximation for bond energies and a good example of how the investigation of

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“…Physico-chemical properties of the pure ethers are available in the literature. (9,10) Both ethers under investigation contain one double bond between C atoms. It was of interest to determine the influence of molecular structure on the specific interaction between the oxygen atom of the ether and the -OH group of the alkanol.…”

Section: Introductionmentioning

confidence: 99%

Excess properties of binary mixtures of an alkanol or an alkane with butyl-vinyl ether oriso-butyl-vinyl ether

Rezanova

Lichtenthaler

2000

The Journal of Chemical Thermodynamics

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Thermodynamic Properties and Ideal-Gas Enthalpies of Formation for Butyl Vinyl Ether, 1,2-Dimethoxyethane, Methyl Glycolate, Bicyclo[2.2.1]hept-2-ene, 5-Vinylbicyclo[2.2.1]hept-2-ene, trans-Azobenzene, Butyl Acrylate, Di-tert-butyl Ether, and Hexane-1,6-diol

Cited by 97 publications

References 69 publications

Catalytic Gas‐Phase Cyclization of Glycolate Esters: A Novel Route Toward Glycolide‐Based Bioplastics

Catalytic Gas‐Phase Cyclization of Glycolate Esters: A Novel Route Toward Glycolide‐Based Bioplastics

Paradigms and paradoxes: organic thermochemistry without hydrogen: carbon oxides and nitrides

Excess properties of binary mixtures of an alkanol or an alkane with butyl-vinyl ether oriso-butyl-vinyl ether

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