Degree: Doctor

Affiliation(s):

CIQUP - FCUP

Bio

Ana Luísa R. Silva (ALRS) completed her PhD in the Faculty of Sciences of the University of Porto (2015), on Molecular Thermochemistry and Calorimetry, with a thesis focused on the energetic vs structural study of 1,3-azoles, using experimental and computational approaches. ALRS is a contracted researcher at FCUP and lecturer of some courses in Chemistry for MSc and BSc degrees, being a member of the Molecular Thermodynamics for Sustainability Group at the Research Centre in Chemistry of the University of Porto (CIQUP) and the Institute of Molecular Sciences (IMS). Currently, ALRS is working on the Energetic and Structural Characterization of Biomass Key Components, having published so far 33 articles in specialized peer-review international journals (1st author in 27). She presented several poster communications and oral presentations at international and national conferences. ALRS has performed peer review evaluations for several manuscripts in international specialized journals and has been supervising 1 PhD student, supervised 9 BSc students, 1 MSc student, and 5 undergraduate/graduated students under the Extracurricular Internship Program at FCUP. ALRS has been involved in different workshops and summer schools (the Junior University of Porto; workshop-School of Chemistry and Biochemistry; LabWeek-Week with Chemistry; "Mostra" of the University of Porto; Open Days of FCUP).


Research interests: Molecular energetics; calorimetry; computational chemistry; phase transitions studies; thermodynamic properties of heterocycles; predictive-schemes of energy-structure for azoles; conformational analysis and tautomeric studies; H-bond interactions; relative thermodynamic stability of heterocyclic compounds; thermochemistry of energetic materials; energetic characterization of biomass-derived compounds.

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Publications
Showing 5 latest publications. Total publications: 41
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1. Thermodynamic properties of benzotriazole derivatives: An experimental and computational study, Silva, ALR Lima, ACMO; da Silva, MDMCR in JOURNAL OF CHEMICAL THERMODYNAMICS, 2023, ISSN: 0021-9614,  Volume: 186, 
Article,  Indexed in: crossref, scopus, wos  DOI: 10.1016/j.jct.2023.107140 P-00Y-Z6Q
Abstract A thermochemical study of 5-methyl-1H-benzotriazole and 5,6-dimethyl-1H-benzotriazole was carried out experimentally using calorimetric techniques and an effusion method. Parallel to that, a computational methodology was also applied. The massic energies of combustion and the enthalpies of sublimation were determined from static bomb combustion calorimetry and Knudsen mass-loss effusion method and/or high-temperature Calvet microcalorimetry, respectively. From these experimental data, the standard molar enthalpies of formation of the two benzotriazoles in the gaseous phase were derived. Additionally, the gas-phase enthalpies of formation of these benzotriazoles and other two methylated derivatives were calculated using the G3(MP2)// B3LYP level of theory. The data obtained allowed the study of the energetic effects associated with the presence of a methyl group in the benzotriazole structure and their comparison with identical effects in homocyclic molecules, namely benzene and naphthalene. The Gibbs energies of formation of the compounds in the crystalline and gaseous phases were also determined to assess their thermodynamic stability.
2. Inside Cover: On the Enthalpy of Formation and Enthalpy of Sublimation of Dihydroxylammonium 5,5′‐bitetrazole‐1,1′‐dioxide (TKX‐50) (Prop., Explos., Pyrotech. 7/2023), Silva, ALR Almeida, ARRP; Ribeiro da Silva, MDMC; Reinhardt, J; Klapötke, TM in Propellants, Explosives, Pyrotechnics, 2023, ISSN: 0721-3115,  Volume: 48, 
Article,  Indexed in: crossref, unpaywall  DOI: 10.1002/prep.202380702 P-00Z-0PN
3. On the Enthalpy of Formation and Enthalpy of Sublimation of Dihydroxylammonium 5,5′-bitetrazole-1,1′-dioxide (TKX-50), Silva, ALR Almeida, ARRP; da Silva, MDMCR; Reinhardt, J; Klapötke, TM in PROPELLANTS EXPLOSIVES PYROTECHNICS, 2023, ISSN: 0721-3115,  Volume: 48, 
Article,  Indexed in: crossref, scopus, wos  DOI: 10.1002/prep.202200361 P-00Y-6ZC
Abstract The thermodynamic characterization of dihydroxylammonium 5,5 '-bitetrazole-1,1 '-dioxide (TKX-50) was reinvestigated. Although TKX-50 is one of the most promising new-generation energetic materials, contradictory reports are found in the literature with regard to its solid enthalpy of formation. The standard (p degrees=10(5) Pa) molar enthalpy of formation of crystalline TKX-50, (175.3 +/- 1.9) kJ center dot mol(-1), was determined experimentally based on the measured standard massic energy of combustion, determined through static-bomb combustion calorimetry. Additionally, the standard molar enthalpy of sublimation of TKX-50, at T=298.15 K, (165.0 +/- 2.4) kJ center dot mol(-1), was derived from vapor pressure measurements determined by a Knudsen mass-loss effusion technique. Finally, different approaches were used in attempts to calculate the standard enthalpy of formation of TKX-50 in the solid state. A critical overview and assessment of the data on the enthalpy of formation of TKX-50 is also presented.
4. Enthalpy of Formation of the Nitrogen-Rich Salt Guanidinium 5,5′-Azotetrazolate (GZT) and a Simple Approach for Estimating the Enthalpy of Formation of Energetic C, H, N, O Salts, Silva, ALR León, GP; da Silva, MDMCR; Klapötke, TM; Reinhardt, J in THERMO, 2023, ISSN: 2673-7264,  Volume: 3, 
Article,  Indexed in: crossref, scopus, wos  DOI: 10.3390/thermo3040033 P-00Z-51X
Abstract The discrepancy between the calculated (CBS-4M/Jenkins) and experimentally determined enthalpies of formation recently reported for the 2:1 salt TKX-50 raised the important question of whether the enthalpies of formation of other 2:1 C, H, N, O salts calculated using the CBS-4M/Jenkins method are reliable values. The standard (p degrees = 0.1 MPa) enthalpy of formation of crystalline guanidinium 5,5 '-azotetrazolate (GZT) (453.6 +/- 3.2 kJ/mol) was determined experimentally using static-bomb combustion calorimetry and was found to be in good agreement with the literature's values. However, using the CBS-4M/Jenkins method, the calculated enthalpy of formation of GZT was again in poor agreement with the experimentally determined value. The method we used recently to calculate the enthalpy of formation of TKX-50, based on the calculation of the heat of formation of the salt and of the corresponding neutral adduct, was then applied to GZT and provided excellent agreement with the experimentally determined value. Finally, in order to validate the findings, this method was also applied to predict the enthalpy of formation of a range of 1:1 and 2:1 salts (M+X- and (M+)2X2- salts, respectively), and the values obtained were comparable to experimentally determined values. The agreement using this approach was generally very good for both 1:1 and 2:1 salts; therefore, this approach provides a simple and reliable method which can be applied to calculate the enthalpy of formation of energetic C, H, N, O salts with much greater accuracy than the current, commonly used method.
5. Energetic Effects in Methyl- and Methoxy-Substituted Indanones: A Synergistic Experimental and Computational Study, Silva, ALR León, GP; da Silva, MDMCR in APPLIED SCIENCES-BASEL, 2023, ISSN: 2076-3417,  Volume: 13, 
Article,  Indexed in: crossref, scopus, wos  DOI: 10.3390/app131810262 P-00Z-0SK
Abstract This experimental and computational study on the energetic properties of 2-methyl-, 3-methyl-, 4-methoxy- and 5-methoxy-indanones has been carried out using mostly calorimetric techniques and a suitable computational approach. The combustion and sublimation/vaporization enthalpies were determined via combustion calorimetry and Calvet microcalorimetry, respectively, allowing for the calculation of the standard molar enthalpies of formation in the gaseous phase. The enthalpy of sublimation of 5-methoxy-indanone was also derived via Knudsen effusion. Additionally, the gas-phase standard molar enthalpies of formation of these compounds were determined from high-level ab initio calculations at the G3(MP2)//B3LYP level of theory. The results obtained experimentally and through the computational approach are in good agreement. Thus, the gas-phase enthalpy of formation of 2-methylcyclopentanone was estimated with this approach. Moreover, the energetic effects associated with the presence of a methyl and methoxy group on the indanone core were analyzed, using the experimental values reported in this work. The presence of a methoxy group contributes to a decrease in the gas-phase enthalpy of formation, of about 153 kJ center dot mol(-1), whereas in the case of a methyl group, the corresponding value is c.a. 35 kJ center dot mol(-1). Finally, a quantitative analysis of the effects of delocalization of the electron density on the methyl-indanones was performed, using NBO calculations at the B3LYP/6-311+G(2df,2p) wave function.