Theoretical investigation of an energetic fullerene derivative

Tan, Bisheng; Peng, Rufang; Li, Hongbo; Jin, Bo; Chu, Shijin; Long, Xinping

doi:10.1002/jcc.21489

Cited by 8 publications

(4 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been calculated that the enthalpy of formation of Cp-5 is 2782.2 kJ mol −1 , while its detonation velocity and pressure are 3282 km s −1 and 4.443 GPa, respectively. 112 Upon complete combustion, the total heat of combustion for Cp-5 is 2.17 × 10 5 kJ mol −1 due to its high carbon content. It seems that this compound may not be useful as the main ingredient of an explosive or a propellant but it might be a good additive for heat-generating energetic compositions.…”

Section: Ems Based On Functionalized C 60 Fullerenementioning

confidence: 99%

Highly energetic compositions based on functionalized carbon nanomaterials

Zhao²,

et al. 2016

View full text Add to dashboard Cite

show abstract

Section: Ems Based On Functionalized C 60 Fullerenementioning

confidence: 99%

Highly energetic compositions based on functionalized carbon nanomaterials

Zhao²,

et al. 2016

View full text Add to dashboard Cite

show abstract

“…The self-consistent-field (SCF) tolerance was set to be 1 × 10 –5 Ha. Compounds that are smaller in size and inorganic in nature having similar reactive features to this work have been extensively studied with success previously in our group using comparable hybrid methodologies. − The accuracy of the BLYP/DNP level of theory has been documented for the reaction energetics and thermochemistry of similar organic and biopolymers. − …”

Section: Computational Methodologymentioning

confidence: 96%

Model Lignin Oligomer Pyrolysis: Coupled Conformational and Thermodynamic Analysis of β-O-4′ Bond Cleavage

et al. 2020

View full text Add to dashboard Cite

The abundance, carbon content, and functionalized nature of lignin make it a promising candidate for targeted valorization to fuels and polymer composites. While lignin modeling by the application of computational chemistry is an active area of research, electronic structure methods have been limited mainly to structures in the dimeric or trimeric range. In this study, we have modeled a lignin structure composed of 10 β-O-4′ linked guaiacyl (G) units, such that this work represents, to the best of our knowledge, the largest structure that has been examined to date using quantum mechanical calculations. As such, this work can provide information on a model, the size of which is more representative of the lignin polymer than has been previously reported. We have calculated bond dissociation enthalpy (BDE) for the homolytic cleavage reaction between each G unit in our model lignin oligomer, which occurs as one of the initial reactions during lignin pyrolysis. The objective of the current work was to determine how or if reactivity within the oligomer changes as a function of bond cleaving position within the chain. The methods used were classical molecular mechanics for conformational sampling and quantum mechanically based density functional theory (DFT) calculations. We have developed a novel and robust method for conformational sampling, which maps the conformational energy landscape efficiently and provides multiple low-energy structures that are then used to determine the BDE values by DFT. Our results for BDE calculations of lignin exhibit significant position dependence along the oligomer chain. To the best of our knowledge, we have reported for the first time the calculated standard thermodynamic properties including enthalpy of formation, heat capacity, entropy, and Gibbs free energy. Despite using a simplified model lignin oligomer structure, our calculated values for standard thermodynamic properties have a remarkable agreement with the experimental values.

show abstract

“…A numerical basis set of double zeta quality plus polarization functions (DNP) was used, which allowed for the truncation of the numerical integration, thus increasing the computational efficiency. We selected the BLYP/DNP level of theory after assessing its performance in studying reaction energetics and predicting thermochemistry for lignin model oligomeric species in our previous two studies , as well as the reported use of BLYP/DNP for studying organic compounds with similar objectives. − The Tkatchenko–Scheffler (TS) method was used as the dispersion correction to include nonbonded interactions . Using the lowest energy conformation for the reactant, geometry optimization was done at the BLYP/DNP level where the convergence tolerances were 2× 10 –5 Hartree for the total energy, 0.004 Ha/Å for the maximum force, and 0.005 Å for the maximum displacement.…”

Section: Computational Methodologymentioning

confidence: 99%

Toward Native Hardwood Lignin Pyrolysis: Insights into Reaction Energetics from Density Functional Theory

et al. 2022

View full text Add to dashboard Cite

Lignin is one of the three structural components of lignocellulosic biomass and the only renewable source for sustainably producing aromatic chemicals. Despite lignin's promise for targeted valorization to fine chemicals, fuels, and polymer composites, a major roadblock is an ambiguity associated with its molecular structure. Due to the lack of an established molecular structure, all types of computational studies from reaction mechanism to reaction energetics are performed with model lignin compounds. Among several thermochemical conversion techniques, lignin pyrolysis has been an active research area for both experimental and computational investigations. Historically, computational studies on the pyrolysis of lignin have mainly been limited to dimeric or trimeric models using electronic structure methods. Very recently, model oligomers up to the size of decamers have been studied with density functional theory (DFT) calculations. While these studies used very simplified models to study lignin's pyrolysis behavior, theoretical investigations on a more realistic lignin structure are warranted to advance its state-of-the-art. To address this, we have modeled a native hardwood lignin polymer consisting of 20 repeating units, including all three monolignols, i.e., guaiacyl (G), syringyl (S), and p-hydroxy coumaryl (H) units, and multiple types of linkages, i.e., β-O-4, 4-O-5, β−β, and β-5. This more realistic molecular model for the wild-type poplar lignin is based on a proposed lignin structure reported in a previous experimental study. The initial stage in lignin pyrolysis involves the homolytic cleavage of β-O-4 linkages present in lignin. The activation energy for homolysis of this linkage is considered to be slightly greater than the bond dissociation enthalpy (BDE) required to cleave it. We used a composite method using molecular mechanics-based conformational sampling and quantum mechanically based density functional theory (DFT) calculations to determine the reaction energetics for this reaction, which indicates the activation energy required for the early stage of lignin pyrolysis. In addition, we calculated standard thermodynamic properties for all species, including enthalpy of formation, heat capacity, entropy, and Gibbs free energy of formation as a function of temperature. This study provides the reaction energetics and standard thermodynamic quantities that could be used in kinetic and reactor modeling for biomass conversion. Additionally, these predictions would be particularly helpful in advancedgeneration biorefinery, where hardwoods can be used as a potential feedstock. Moreover, the predictions reported in this study will benefit further computational studies and cross-validation with pyrolysis experiments, ultimately contributing to solving the puzzle of the structural ambiguity of lignin.

show abstract

Theoretical investigation of an energetic fullerene derivative

Cited by 8 publications

References 34 publications

Highly energetic compositions based on functionalized carbon nanomaterials

Highly energetic compositions based on functionalized carbon nanomaterials

Model Lignin Oligomer Pyrolysis: Coupled Conformational and Thermodynamic Analysis of β-O-4′ Bond Cleavage

Toward Native Hardwood Lignin Pyrolysis: Insights into Reaction Energetics from Density Functional Theory

Contact Info

Product

Resources

About