Research Team Members:

Rui Fausto is Full Professor at the Department of Chemistry of the University of Coimbra and is the LMCB team leader. He integrates the Directive Board of the World Association of Matrix Isolation Scientists and is Vice-President of the Stearing Committee of the EUCMOS series of meetings. His main interests range from spectroscopy to photochemistry and theoretical chemistry. In 2004 and 2005 he received the Excellence Prize of the Portuguese Science Foundation. Igor Reva was born in Kharkov, Ukraine. He has PhD degree in Biophysics and Molecular Physics (Kharkov) and in Chemistry (Coimbra). His specialization is photochemistry, molecular structure and vibrational properties of molecular systems at low temperature. He was awarded a Prize of the National Academy of Sciences of Ukraine for the best work of young scientists (with S.Stepanian); a Prize of the Academia Europaea for young scientists and a Humboldt Fellowship, among others. He is fluent in five languages. Andrea Gómez-Zavaglia was born in Argentina. She obtained her Ph.D. in Biochemistry (La Plata). Her main interests centered on the spectroscopy of biomolecules, cryoprotection and photochemistry of molecules with biological relevance (saccharins, tetrazoles, aminoacids, dicarbonyls). In 1999, she won the "Jorge A. Miller" Prize of the Argentinian Association of Food Technologists and, in 2006, the Prize "Maria Inés Cereijo" for the best article on microbiology of the Argentinian Microbiology Association. Agnieszka Kaczor was born in Poland. She obtained her Ph.D. in Chemistry (Krakow) and was post-doctoral fellow at the University of Florida. Her main interests relate with spectroscopy, structure and reactivity of biochemically relevant molecules (aromatic aminoacids, saccharins, azirines) and computational chemistry. Ermelinda Maçôas obtained her Ph.D. in Chemistry at the University of Coimbra. Her main interests center on the investigation of the vibrational dynamics and energy relaxation processes in solid state. She was post doc at the University of Helsinki and Marie Curie Grant holder at the Jyvaskylan University (Finland). She received the Prize "Stimulus to the Scientific Investigation" granted by the Foundation Calouste Gulbenkian to young researchers. Susana Jarmelo obtained her Ph.D. in Chemistry at the University of Coimbra. She was visiting researcher at the University of Leuven, Case Western Reserve University (Cleveland) and at the Institute of Physics of the Polish Academy of Sciences at Warsaw. Her actual interests focus the spectroscopy, structure and reactivity of novel biodegradable polymers and their precursors.
Rui Fausto
(Full Professor)		 Igor Reva
(post doc)		 Andrea Gómez-Zavaglia
(post doc)		 Agnieszka Kaczor
(post doc)		 Ermelinda Maçôas
(post doc)		 Susana Jarmelo
(post doc)
Archna Sharma was born in India. She obtained her Ph.D in Chemistry (Jammu), speciality Theoretical Chemistry. Her current interests centered on the investigation of structure and reactivity of carbonyl compounds with biochemical relevance using both quantum chemical methods and matrix-isolation vibrational spectroscopy. Nihal Kus was born in Turkey. She graduated in Physics (Anadolu University) and is now waiting for her Ph.D. final exam (Physics; Osmangazi University Eskisheir). Her research work focus on the structure and photochemical reactivity of coumarin derivatives. Susana Breda is M.Sc. in Chemistry (Coimbra). She was visiting researcher at the Institute of Physics of the Polish Academy of Sciences (Warsaw) and at the Federal University of Paraíba (João Pessoa). Her interests center on the study of the structure, spectroscopy and reactivity (both thermal and photochemical) of derivatives of furanones and pyrones, matrix-isolation spectroscopy and excited-states quantum chemical calculations. Pablo Mobili was born in Argentina. He graduated in Biochemistry (La Plata) and has been awarded an Alban Program international research grant. His main current scientific interests are the study of protein structure and function using spectroscopic, thermodynamical and microbiological methods. In 2001, he got one of the Prizes awarded to the ten best Exact Sciences' students of the University of La Plata. Luís Frija graduated in Chemistry at the University of Algarve. His current interests are: synthesis of heterocyclic compounds with potential biological activity (tetrazoles, saccharins, benzisothiazoles), organic photochemistry in solution and inert cryogenic matrices, heterogeneous and homogeneous catalysis and computational chemistry. Ana Borba is M.Sc. in Chemistry (Coimbra). Her current scientific interests include the investigation of the structure, spectroscopy and reactivity of amine and amide-substituted azines and diazines using matrix-isolation and jet spectroscopies and quantum chemical methods. She is also investigating the effects of these compounds on the properties of biological membranes. In 2003, she was awarded the FCTUC/CGD "F. Sousa Gomes" Prize for the best Industrial Chemistry Student of the University of Coimbra.
Archna Sharma
(post doc)		 Nihal Kus
(Ph.D student)		  Susana Breda
(PhD student)		 Pablo Mobili
(PhD student)		 Luís Frija
(PhD student)		 Ana Borba
(PhD student)
Susy Lopes was born in Canada. She is M.Sc. in Physical Chemistry (University of Coimbra). Her main interests center on the study of the structure and reactivity of three-membered heterocycles of nitrogen (azirines, diazirines, aziridines, diaziridines) and conformational flexibility in alpha-dicarbonyls. Juracy Junior was born in Brasil. He is M.Sc. in Theoretical Chemistry (Federal University of Paraíba). His studies center on the structure and photochemical reactivity of CFCs and HCFCs using a concerted theoretical and spectroscopic approach. Cláudio Nunes graduated in Chemistry at the University of Coimbra and is waiting for his M.Sc. in Chemistry final exam. His current research interests focus on the synthesis and characterization (structural and dynamical) of small heterocycles containing nitrogen. In 2005, he received the Prize for the best Chemistry student of the University of Coimbra. Rui Almeida graduated in Chemistry at the University of Algarve. His studies center on the investigation of the structure, spectroscopy and reactivity of derivatives of saccharin by quantum chemical methods and matrix-isolation spectroscopy. Alcides Simão graduated in Chemistry at the University of Coimbra. He was visiting researcher at the University of Buenos Aires. His studies focus on the structure and properties of simple phosphorous containing organic molecules and their interaction with biological systems. Luís Duarte graduated in Chemistry at the University of Oporto. His work centers on the determination of the preferred structures of novel bisphosphonates with potential uses in bone therapy and their interaction with hydroxyapatite, using molecular modelling methods.
Susy Lopes
(PhD student)		 Juracy Junior
(PhD student)		 Cláudio Nunes
(PhD student)		 Rui Almeida
(M.Sc student)		 Alcides Simão
(M.Sc student)		 Luís Duarte
(Lic. BIC holder)
Ana Casteleiro is undergraduate Chemistry student. Her last year scientific project deals with the spectroscopic properties of transition metals long chain carboxylates and thermophysical propeties of these compounds.          
Ana Casteleiro
(student)		          

 

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On Going Research Projects:
 

This research project focus on the study of intermolecular interactions in a series of biologically relevant organic families of compounds and their relevance to polymorphism, phase transition properties and solution processes. Globally, the investigation is directed essentially to problems usually considered by crystal engineering, since the study of the whole chain of processes: monomeric solute ® molecular aggregates in solution ® solid phases separated from a given solution ® solid-solid phase transitions, is considered in this research programme. The project takes advantage of the essentially complementary nature of the thermodynamic and spectroscopic methods to look simultaneously at the macroscopic scale and at a molecular level. Such approach enables a very precise characterisation of the macroscopic phenomena under analysis and to evaluate the most important processes that determine these phenomena at a molecular level. In addition, as a complement to the experimental studies, up-to-date molecular modelling methods are systematically used, to provide solid theoretical foundations to the physicochemical interpretations extracted from the experimental data.

The specific objectives of the project can be summarised as follows:

(A) - Obtaining a detailed structural, spectroscopic and thermodynamic description of the monomers of the various systems under analysis, as a starting point to the study of the corresponding aggregates and the relevant macroscopic phenomena. Enabling a detailed knowledge of the molecules which act as constituting units of the complex systems to be studied later on, these studies assume particular importance as a way to get the basic information required by the studies that look at the more complex problems and constitute the main objective of the project. The equilibrium structures of the various possible conformers of the different monomeric species, their relative energies, vibrational spectra and main intramolecular interactions are obtained using noble gas matrix isolation spectroscopy and theoretical calculations at the required levels of theory (ab initio or DFT quantum chemical calculations or molecular mechanics).

(B) -  Characterising the fundamental intermolecular interactions involved in the formation of aggregates of the different compounds under analysis, for the pure substances and in solution of different solvents. Particular emphasis is given to the study of the hydrogen bond formation processes. These studies are undertaken by a concerted vibrational spectroscopy and calorimetry (differential calorimetry and thermomicroscopy) approach, complemented by theoretical calculations. These later are performed at various levels of approximation, including the simulation of the nucleation processes by molecular dynamics calculations carried out using the Cerius2 software.

(C) - Determining the different possible phases of the compounds under study, obtained from crystallisation from different solvents, in a wide range of temperatures, going from near the absolute zero to above room temperature, by differential scanning calorimetry and vibrational spectroscopy, and to obtain the phase transition thermodynamic properties.

(D) - Characterising the different phases observed from a structural point of view, explain their occurrence and main features in terms of intermolecular interactions between their constituting units, and establishing fundamental structure/properties relationships that may be useful to understand the structural, thermodynamic and spectroscopic properties experimentally observed in the families of molecules under analysis, as well as some aspects of their physicochemical behaviour. 

 

The storage of biological material at sub-zero temperatures plays nowadays an essential role in several domains of human activity, in particular in Medicine and Biology. During the preservation procedures, the cell membrane is the main target for damage. The injury caused by freezing usually destroys the barrier for ion permeation and, in consequence, a collapse of the membrane potential is produced. It becomes clear that the preservation of biological membranes is essential in storage processes. Hence, the choice of an adequate cryoprotectant is essential to successfully attain this aim.

In general, the target of cryoprotectants is the membrane. However, very often the experimental research intending to understand the mechanisms of such interactions is complicated by the lack of reliable data on the constituting units and specific interactions among them. A successful analysis of phenomena such as aggregation and molecular recognition, which are relevant to cryoprotection, requires a detailed knowledge of the basic information on the structure and properties of the interacting chemical groups that might be obtained by theoretical models or gas phase studies. A better approach to this problem is to look at those species in an inert condensed media, where the specific “solute”/”solvent” interactions are minimized but some of the most fundamental conditions of the “real” system under study are maintained (e.g., packing effects, reduced mobility). The matrix-isolation technique, where the target molecular species are embeeded in a low temperature inert matrix, satisfies the requisites above mentioned.

To attain the objectives of this work, a precise physicochemical characterization of a series of substances and mixtures of substances (derivatives of aminoacids, hydroxyacids and polihydroxylated compounds), both at the molecular and thermodynamic levels, needs to be first established. Spectroscopic and calorimetric methods are being used complementary to fulfill this aim. Studies on matrix-isolated monomeric species and their small aggregates, cryogenic solution, crystals and glassy states of these potentially new cryoprotectants at very low temperatures (9K) are also being undertaken. On the whole, they are hope to provide a deep insight on the structures and spectroscopic properties of the target compounds as well as on their intermolecular interactions, particularly H-bonds. Molecular modeling methods are also being systematically used, to provide solid theoretical foundations to the physicochemical interpretations extracted from the experimental data.

 

Long term cryogenic storage of biological material, like living cells and tissues, is an active area of research due to its easily recognisable social impact in several areas of the human activity (e.g., transplantation). In general, the methods developed for the cryopreservation of cells have not proved to be directly transferable to multicellular, organised tissues and organs. For these systems, vitrification (glass formation) has been recognised as the most promising approach to overcome the problem of ice formation during freezing, which in the case of the highly organised structures of an organ or tissue has been shown to result in devastating and fatal damage.

Vitrification requires that the biomaterial be perfused with a suitable cryoprotectant, the role of which is to protect the material from the physicochemical and biochemical effects of low temperatures, and also to promote the formation of the vitreous state. The choice of a suitable cryoprotectant is critical to a successful vitrification and depends on a number of factors, including solute toxicity, solute/water interactions and cooling rate. Unfortunately, with the cryoprotectants presently used, the concentration needs to be high to achieve complete vitrification and thus toxicity becomes a problem.

This research project aims to develop new more efficient vitrifying procedures involving new cryoprotectants which present lower toxicity than those actually available.

To attain this fundamental objective, a precise physicochemical characterisation of a series of substances and mixtures of substances, both at the molecular and thermodynamic levels, need to be first established. In this project, this is achieved by complementary use of spectroscopic and calorimetric methods. In addition, as a complement to the experimental studies, up-to-date molecular modelling methods are systematically used to provide solid theoretical foundations to the physicochemical interpretations extracted from the experimental data. Once a suitable cryoprotectant system, showing the desired physicochemical properties, is found, it still must be tested with respect to its intrinsic toxicity, because, even in the most favourable expected conditions, relatively large cryoprotectant concentrations must be used in order to attain the desired physicochemical conditions. Thus, in this project, the evaluation of the intrinsic biological toxicity of the identified candidate systems to act as cryoprotectant agents is also investigated. 

 

 

Main Equipment: