Degree: Habilitation

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Affiliation(s):

FCUP

Bio

Maria D. M. C. Ribeiro da Silva. Completed the Habilitation in Chemistry in 2001, from the University of Porto (Faculty of Sciences), the PhD in Chemistry in 1985, from the University of Porto (Faculty of Sciences), the Degree in Chemistry in 1976, from the University of Porto (Faculty of Sciences ) and a Bachelor's degree in Chemistry in 1974, from the University of Porto (Faculty of Sciences).

Associate Professor (1993-2023) in the Department of Chemistry and Biochemistry, Faculty of Science, University of Porto (FCUP). Invited Associate Professor (2024-)

Vice-President of Department of Chemistry, FCUP (2002-2003). Head of the Committees for M.Sc. Degrees in Chemistry and in Chemical Education (1997 – 2005) and Director of the 2nd Cycle of Studies in Chem. (Bologne System) since 2007 until January 2018. Since 2009 until September/2017, she has been the Coordinator of Erasmus Mundus SERP Chem in UP. She was nominated as the Portuguese Chemistry Mentor for EU Science Olympiads (2009-2017) and President of the XXIV Ibero-American Chemistry Olympiad in Portugal (2019). She was member of the Coordinator Council of Junior University ( UP; 2008-2023.). She was Member of the Representatives Council in FCUP (2018-2023). Conference Chair and Organizer of MEDICTA 2023 (16th Mediterranean Conference on Calorimetry and Thermal Analysis, Porto, Portugal, 2023) and 11ENQF (11º National Physical Chemistry Meeting, Porto, Portugal, 2011). Organizer of Porto Summer School on Calorimetry and Thermal Analysis (Porto, Portugal, 2023).

She develops her work in the area of Exact Sciences, with an emphasis on the area of Physical Chemistry (Thermochemistry and Molecular Energetics).

Author of ~210 publications in international journals, 3 book chapters,  and co-author in several manuals for laboratorial activities. Supervisor or co-Supervisor of 11 Ph.D. theses (10 completed), 21 M.Sc theses. and 51 B.Sc. theses in Chemistry. Supervisor of 10 Pos-Doctoral Projects. Member of the scientific team of several research projects awarded by national or international funding agencies (coordinator of two projects).

Scientific Interests: Molecular energetics of oxygen/nitrogen/sulphur heteropolycyclic compounds; Energetics of N-oxide nitrogen heterocyclic derivatives; Energetics of organic compounds (basic structures for larger molecules); Energetics of the metal-ligand bonds in organometallic compounds.

Techniques expertise: Combustion Calorimetry/ DSC/ Calvet Microcalorimetry/ Reaction-Solution/Calorimetry/Knudsen-effusion techniques.

Publications
Showing 5 latest publications. Total publications: 221
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1. Vapor Pressures and Energies of Combustion of R-1,2,4-triazoles (R=3-methyl, 4-methyl, and 4-amino), Silva, ALR; Lima, ACMO; Neuer, A; Klaptke, TM; da Silva, MDMCR in JOURNAL OF CHEMICAL AND ENGINEERING DATA, 2026, ISSN: 0021-9568,  Volume: 71, 
Article in Press,  Indexed in: crossref, scopus, wos  DOI: 10.1021/acs.jced.5c00632 P-01B-2Y6
Abstract This study investigates the volatility of widely utilized triazole derivatives-3-methyl-1H-1,2,4-triazole, 4-methyl-4H-1,2,4-triazole, and 4-amino-4H-1,2,4-triazole-through vapor pressure measurements obtained via the transpiration method in a temperature range of 288-353 K. The standard molar enthalpies of formation, in the crystalline state, at T = 298.15 K, were derived from the standard molar enthalpies of combustion, which were obtained from static bomb combustion calorimetry. From the experimental results, the standard molar enthalpies of formation in the gaseous phase at T = 298.15 K were derived. For comparison purposes, quantum chemical calculations at the G3(MP2)//B3LYP level were performed, using a set of working reactions and the gas-phase enthalpies of formation of both compounds were estimated; the results are in very good agreement with experimental data. Differential scanning calorimetry measurements further supported the investigation by providing complementary thermodynamic parameters, specifically molar heat capacities of triazoles. The vapor pressure data provide key insights into phase transitions, handling risks, detection potential, and the fundamental thermodynamic behavior of these compounds. This work contributes to the improvement on the validation of predictive models relevant to these substances.
2. Energetic study of maltol and triacetic acid lactone, Silva, ALR; Pereira, AMM; Silva, PFM; Morais, VMF; da Silva, MDMCR in JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY, 2026, ISSN: 1388-6150, 
Article in Press,  Indexed in: crossref, scopus, wos  DOI: 10.1007/s10973-026-15705-y P-01C-WKK
Abstract This work presents a combined experimental and computational thermochemical study of 3-hydroxy-2-methyl-gamma-pyrone (maltol, MAL) and 4-hydroxy-6-methyl-alpha-pyrone (triacetic acid lactone, TAL). Pyrones are biomass-derived molecules known as promising platforms to produce high-value chemicals and biofuels, although reliable thermodynamic data for this family of compounds remain scarce. Herein, we report accurate thermophysical and thermochemical properties obtained from calorimetric experiments and high-level quantum chemical calculations, aiming to support future studies on their conversion pathways, including hydrogenation and hydrodeoxygenation.The thermal behavior of MAL and TAL was investigated by differential scanning calorimetry (DSC), while their combustion energies were measured by static bomb calorimetry, enabling the determination of the corresponding enthalpies of formation in the crystalline phase. Phase transition studies were further performed using the Knudsen effusion mass-loss method and the Calvet microcalorimetry technique. From the experimental data, the gas-phase enthalpies of formation were derived. The quantum chemical calculations performed with the G4(MP2) composite method, showed agreement with the experimental data, supporting the reliability of the results. Additionally, some conversion reactions (mainly ring-opening and decarboxylation) of model biomass-derived cyclic compounds were studied.
3. Thermochemical investigation of three 5-R-thio-1,3,4-thiadiazole derivatives: R = methyl, ethyl, Silva, ALR Lima, ACMO; Gonçalves, JM Morais, VMF; da Silva, MDMCR in JOURNAL OF CHEMICAL THERMODYNAMICS, 2025, ISSN: 0021-9614,  Volume: 202, 
Article,  Indexed in: crossref, unpaywall, scopus, wos  DOI: 10.1016/j.jct.2024.107423 P-017-CBA
Abstract An experimental and computational thermochemical study is reported focus on the relationship between the energetic properties, the structural characteristics and the inherent reactivity of three thiothiadiazoles: 2-amino5-(methylthio-)-1,3,4-thiadiazole, 2-amino-5-(ethylthio-)-1,3,4-thiadiazole and 2-mercapto-5-methylthio-1,3,4thiadiazole. From the DSC measurements, the enthalpies of fusion and the respective onset temperatures were determined. The standard molar energies of combustion of the (alkylthio)-1,3,4-thiadiazoles were determined by rotating bomb combustion calorimetry. The corresponding standard molar enthalpies of sublimation, at T = 298.15 K, were derived from high-temperature Calvet microcalorimetry measurements and the study of the dependence of the compound's vapour pressures with the temperature, using the Knudsen-effusion technique. The combination of these experimental results enables the calculation of the standard molar enthalpies of formation in the gaseous state, at T = 298.15 K, which are discussed in terms of structural contributions. The latter property was also determined from high-level ab initio molecular orbital calculations at the G3(MP2)//B3LYP level of theory. The computed values are in good agreement with the experimental ones. In addition, a conformational and tautomeric study was conducted using the same approach, in order to provide insight on the amino/imino and thiol/thione tautomerism of the compounds studied. The amino form predominates in aminothiadiazoles, while the thione form prevails in mercaptothiadiazole. Moreover, the relative thermodynamic stability of each compound was also evaluated showing that in both solid and gas phases, the most stable species is the mercaptothiadiazole (in its thione form). The thermochemical results of the (alkylthio)-1,3,4-thiadiazoles show a good agreement with the NBO (natural bond orbitals) analysis results.
4. Thermodynamic Properties of γ- and δ-Lactones: Exploring Alkyl Chain Length Effect and Ring-Opening Reactions for Green Chemistry Applications, Silva, ALR; León, GP; Lukes, V; Klein, E; da Silva, MDMCR in MOLECULES, 2025, Volume: 30, 
Article,  Indexed in: crossref, scopus, wos  DOI: 10.3390/molecules30020399 P-017-TE5
Abstract An extensive thermochemical study of gamma-undecanolactone and delta-undecanolactone has been developed using two complementary calorimetric techniques. The combustion energy of each compound was determined by static-bomb combustion calorimetry, and the corresponding enthalpy of vaporization was determined by high-temperature Calvet microcalorimetry, in which both properties of each compound are reported at T = 298.15 K. The standard molar enthalpy of formation in the gas phase of each lactone was derived by the combination of the experimental results. Additionally, high-level computational calculations were carried out, using composite ab initio G4 and G4(MP2) methods, as well as DFT M06-2X/6-311++G(d,p) approach, to estimate the corresponding enthalpy of formation in the gas phase. The experimental and computational results are in good agreement. The G4 and G4(MP2) methods show the best accordance with experimentally determined gas phase enthalpies of formation. The experimental results are discussed in terms of structural contributions to the energetic properties of the lactones studied, as well as to other alkylated gamma- and delta-lactones, and empirical correlations are suggested for the estimation of the standard molar enthalpies of formation, at T = 298.15 K, for other alkylated gamma- and delta-lactones, both in the liquid and gaseous phases, as well as for the respective enthalpies of vaporization. Finally, the thermochemistry of individual steps of lactone ring opening and successive decarboxylation mechanism, including the identification of transition states, was studied using the M06-2X/6-311++G(d,p) approach.
5. On the Vapor Pressures, Phase Transitions, and Solid-State Fluorescence of 2-(2-Hydroxyphenyl)benzoxazole and 2-(2-Hydroxyphenyl)benzothiazole, Ferraz, JMS; Silva, ALR; Romagnoli, L; Ciccioli, A; Freitas, VLS; da Silva, MDMCR Ciprioti, SV in CHEMPHYSCHEM, 2025, ISSN: 1439-4235, 
Article in Press,  Indexed in: crossref, scopus, wos  DOI: 10.1002/cphc.202500570 P-01A-PNV
Abstract Benzazole derivatives exhibit distinctive photophysical behavior due to excited-state intramolecular proton transfer (ESIPT), making them promising candidates for optoelectronic applications such as organic light-emitting diodes (OLEDs) and fluorescent sensors. Understanding their sublimation energetics, phase behavior, and emissive properties is essential for both fundamental studies and materials design. This article reports an investigation on two benzazole derivatives-2-(2-hydroxyphenyl)benzothiazole and 2-(2-hydroxyphenyl)benzoxazole (HBO)-through studies of thermal analysis, vapor pressure measurements, and fluorescence spectroscopy to establish structure-property relationships. Thermal stability and phase transitions are characterized using simultaneous thermogravimetry-differential scanning calorimetry (TG-DSC) and heat-flux DSC. Vapor pressures are determined using both Knudsen effusion mass loss and mass spectrometry. The derived standard molar enthalpies of sublimation, vaporization, and fusion highlight the presence of heteroatom (S versus O) on intermolecular interactions. Solid-state fluorescence measurements reveal strong emission in both compounds, with a large Stokes shift-consistent with ESIPT-and complex spectra attributed to solid-state molecular packing. This comprehensive experimental strategy delivers benchmark thermodynamic and photophysical data, offering new insights into the interplay between molecular structure, thermal behavior, and fluorescence of benzazole derivatives. Such understanding is relevant for the development of advanced optoelectronic materials.