Levoglucosan: A Calorimetric, Thermodynamic, Spectroscopic, and Computational Investigation

Abstract

A comprehensive analysis of the thermochemical properties of levoglucosan, using static bomb combustion calorimetry, Knudsen effusion technique, and differential scanning calorimetry, is presented. The experimental results allow us to derive the enthalpy of formation, in the gaseous phase, and thereafter to do a comparison with the same parameter obtained computationally. The good agreement between the experimental and computational results gives confidence to our determinations, particularly when they are compared with others already reported in literature. After testing the computational methodology, the ionization energy, electron affinity, proton affinity, gas-phase basicity, gas-phase acidity, and bond dissociation enthalpies of levoglucosan were also obtained. The presence of intramolecular hydrogen bonds in the most stable conformation of levoglucosan was verified by applying Quantum Theory of Atoms in Molecules calculations. Furthermore, a joint differential scanning calorimetry and temperature dynamic Fourier transform infrared (FT-IR) spectroscopic study was used to study the crystalline phase of levoglucosan between 298.15 K and the melting temperature.

The fundamentals of biocarbon formation at elevated pressure: From 1851 to the 21st century

“…The discovery by Scott, Piskorz, Radlein and their co-workers of glycolaldehyde as a significant byproduct of cellulose fast pyrolysis, and the mechanism of this commercially important reaction as detailed by Richards and his co-workers, are reviewed by Antal and Varhegyi [11]. The heat of vaporization of levoglucosan and its vapor pressure have been reported by Milosavljevic, Oja and Suuberg [26,27], and Rocha et al [28] Their findings indicate that the vapor pressure of levoglucosan greatly exceeds 0.1 MPa at pyrolysis temperatures; consequently it boils vigorously during pyrolysis at 0.1 MPa and its rate of mass transfer to the vapor phase is high. All these findings taken together unveil the role of pressure in directing the pyrolysis reactions towards the formation of carbon.…”

Experimental and theoretical study of thermodynamic properties of levoglucosan

“…According to Rocha et al [7], D c H o m of the studied compound is equal to À(2831.1 ± 1.9) kJ Á mol À1 .…”

“…The standard molar enthalpies of sublimation were D g crII H m (362.7 K) = (125.1 ± 1.0) kJ Á mol À1 for the rigid crystal and D g crI H m (395.8 K) = (100.3 ± 5.9) kJ Á mol À1 for the plastic crystal. Rocha et al [7] used the same method for the measurements in the temperature range (361 to 379) K. The standard molar enthalpy of sublimation for the rigid crystal was D g crII H m (37 0.1 K) = (131.1 ± 3.4) kJ Á mol À1 for the rigid crystal. Booth et al [8] measured the saturated vapor pressure close to the ambient temperature.…”

“…A notable disagreement for the enthalpy of sublimation obtained by various http://dx.doi.org/10.1016/j.jct.2015.01.005 0021-9614/Ó 2015 Elsevier Ltd. All rights reserved. authors [6,7] makes it reasonable to carry out additional vapor pressure measurements for levoglucosan.…”

Interplay of thermochemistry and structural chemistry, the journal (volume 24, 2013, issues 5–6) and the discipline

“…Meaningful thermochemical comparison can be made with the related fluoro- [154], chloro- [155], and iodo-benzonitriles [156].…”