PHOTOCHEMISTRY

Author: REY PUIGROS OSCAR.
Year: 2003.
University: RAMÓN LLULL [www.url.edu].
Place of defense: ESCOLA TECNICA SUPERIOR IQS.
Place of preparation: ESCOLA TÈCNICA SUPERIOR IQS.

Author: Flors Ong Cristina.
Year: 2004.
University: RAMÓN LLULL [www.url.edu].
Place of defense: Escuela Técnica Superior IQS.
Place of preparation: Escuela Técnica Superior IQS.

Summary: We have studied the properties of secondary metabolites photosensitising based on fenalenona and defense-related plant agents against invaders. All fenilfenalenonas studied and alkaloid oxoaporfínico oxoglaucina are capable of fotosensibilizar singlet oxygen, efficient variable depending on the substituents and the solvent. In the case of 9-fenilfenalenonas, its low efficiency fotosensiblizante is due to competition with a process of transferring cargo intramolecular that disables the excited states. It shows that the core of fenalenona little regard to the reactive hydrogen abstraction, but rather reactive in charge transfer fotoinducida. Their interaction in critical condition and excited with biomolecules such as nucleosides and DNA, has also been studied. To complement studies of singlet oxygen in solution, have created images of this species in plant through a combination of fluorescent probes and a high-resolution digital camera. We discuss the role of cromóforo of fenalenona and, more fundamentally, of singlet oxygen, in defending plants.

Author: ORTEGA MARTÍNEZ-LOSA MARÍA.
Year: 2004.
University: LA RIOJA [www.unirioja.es].
Place of defense: UNIVERSIDAD DE LA RIOJA.
Place of preparation: UNIVERSIDAD.

Summary: The main theme of this report is to study the photochemical reactivity of iminas and, in particular, the reactions of fotoacoplamiento and fotorreducción to that lead. As final products are obtained, respectively 1,2-diaminas neighborhood and secondary amines, nitrogen compounds that are highlighted by its many applications at the biological, medical or synthetic. Thus, the first part of the work focuses on the stereoselective synthesis of 1,2-diaminas neighborhood through reaction fotoacoplamiento of iminas in the presence of metals, whose study has developed a new methodology "one-pot" for the preparation and separation of 1,2-diaminas wide gram. Then, the processes have been addressed photo-reduction of iminas to secondary amines, as we have said, are part of the skeleton of many bioactive molecules. In this regard, the combination of light and a solvent alcohol as a reducing agent is proposed as an alternative to get these synthetic compounds more repetuosa to the environment than traditional methods of reducing iminas. Finally, our interest in the reactions of fotoacoplamiento and fotorreducción has not been limited only to describe its reactivity, but also has delved into its mechanistic study, which has helped develop a proposal for both single mechanistic processes.

Author: MARTIN TORRES VIRGINIA.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: INSTITUTO DE CIENCIA Y TECNOLOGIA DE POLIMEROS, CSIC.

Summary: The study of the molecular environment of a low molecular weight compound through its fluorescence has had an extensive application in chemistry, biology and medicine, and represents a major advance in the detection and study of many different processes. The development of applications is due to the many advantages that introduced this technique; chief among them is its high sensitivity and selectivity as well as being a non-destructive method that enables analysis in situ at room temperature. Technological innovations in lasers and detection systems have reduced the response time, so that has expanded the number of phenomena and processes that can be studied based on this technique. In the area of polymers have been carried out numerous studies that the results obtained using fluorescence correlate with those from other techniques. In general, polymers fluoresces not suitable for their application as sensors, which has carried out the design and synthesis of numerous fluorescent probes to examine specific properties of the microenvironment (polarity, microviscosidad, pH ...). Thus, it has expanded its scope to monitor other processes such as polymerization reactions and physical aging of polymer materials. In more specific details the following specific objectives: 1. Summaries of fluorescent probes sensitive to changes in its microenvironment during the processes under study. 2. Characterization fotofísica of probes. 3. Studies of the influence of the polarity of the solvent (solvatocromismo) in the emission characteristics. 4. Determination of the moments of dipolar fundamental and excited states of cromóforos. 5. Study of the reactions of polymerization fotoiniciada monomer metacrílicos, both in homogeneous and heterogeneous phase (microemulsiones). The aim has been to correlate the variation of the fluorescence during the time of irradiation to the degree of conversion attained. 6. Process fotocurado adhesive under irradiation with light continuous policromática by fluorescence. In order to establish correlations between changes in fluorescence probes and the degree of conversion has been achieved addressed studying these reactions by infrared spectroscopy with Fourier transform in real time. 7. It was considered of interest to extend the method based on fluorescence monitoring process fotocurado adhesive under pulsed laser irradiation with light. 8. The sensitivity of cromóforos to slight variations in its microenvironment has enabled the study of the process of diffusion of water in adhesives business by fluorescence. The results were compared with those obtained by gravimetry. Synthesis of new fluorescent probes. We have synthesized fluorescent probes with six new structures aminoaromáticas of D-type-A, D: and A donor: acceptor, similar to other synthesized in our group. The products obtained have been characterized by conventional techniques (spectroscopy 1H-RMN, 13C-RMN, UV-Vis, IR, 8 spectrum 1ff8 metría mass and elemental analysis), to ensure its structure and purity. Characterization fotofísica of probes, study solvatocrómico and theoretical study. We have determined the parameters of absorption and emission of new probes (wavelength of maximum absorption and emission, molar absorption coefficients and fluorescence quantum yields) in twelve different polarity solvents. The absorption spectra, in addition to the band of transition-*, presented a band to higher wavelengths characterized by high molar absorption coefficients, which is due to a shift caused by charge transfer between the donor and acceptor groups. The strong dependency of maximum fluorescence emission, as well as the maximum absorption indicate the existence of an excited state more relaxed than the Franck-Condon, a state charge transfer intramolecular (ICT). It has been determined dependence fluorescencia-polaridad (solvatocromismo) through empirical correlations defining the polarity of the solvent, scales ET30, * and SPP. Correlations always better in their emission parameters that absorption. The various models to justify solvatocromismo establishing relations between displacement solvatocrómicos and electronic distributions of the molecule in their excited states. Generally, those molecules experiencing a major change in its moments dipolar permanent exhibit accused solvatocromismo. It has been proven this fact probes for DMA-2, 3, DMA-2, 4 and DMA-2, 5 by the theoretical calculation of its moments dipolar states in central and excitado.Las probes DMA-2, 3, DMA 2.4 and DMA-2, 5, in addition, have proved to be sensitive to different metallic cations (Cu2 + and Zn2 +), which is attributed to the disruption of the electronic structure for coordination with metal rings diacina. Study of light curing reaction of monomers metacrílicos using fluorescence behavior of probes DMA-2, 3, DMA-2, 4 and DMA-2, 5 has been evaluated by studying the reaction of polymerization of three monomers monofuncionales (methacrylate of ciclohexilo, CHMA; methacrylate laurilo, MAL and methacrylate 2-Ethylhexyl, EHMA) and two difuncionales (dimethacrylate of 1,6-hexanodiol, HDDMA and of diethylene glycol dimethacrylate, EGDMA) using fluorescence. The results were correlated with those obtained by differential scanning calorimetry (DSC). The measures calorimetry and fluorescence were carried out simultaneously through a coupling system calorímetro-fluorímetro designed and constructed in our laboratory. The selected fotoiniciador commercial fragmentation, the oxide of a (2,4,6-trimetilbenzoil) -fenilfosfina, Irgacure 819. The variation of fluorescence during the polymerization reaction probes employed follows the kinetic profile of the reaction obtained by calorimetry. Also, the sensitivity of the probe to the changes is high enough, both conversions to limit small conversions. Process fotocurado of microemulsiones bicontinuas The microemulsiones are isotropic mixtures, composed of a thermodynamically stable aqueous phase and organic phase stabilized by a sufactante or mixture of surfactants. Due to the small size of the particles in dispersion polymerization are transparent and allows the synthesis of ultrafine particles of latex whose size ranges between 10 and 100 nm. The system studied in this work has been: methyl methacrylate (MMA), methacrylate dimetilaminoetilo (DMAEMA) of ethylene glycol dimethacrylate (EGDMA) as agent entrecruzante and water, stabilized with an anionic surfactant, dodecilsulfato sodium (SDS) or cationic bromide cetiltrimetilamonio (CTAB). We studied the phase diagrams of the systems to establish compositions that led to the formation of microemulsiones; this diagram was made following the instructions given by various authors in the bibliography. By conductimetría identified various areas microemulsion (o / w, bicontinuas w / o). Of the microemulsiones obtained were chosen five bicontinuas for monitoring the reaction of light curing. They remained constant proportion MMA / DMAEMA (50:50), while being varied the amount of water respect to the total amount of monomers (30:70, 35:65, 40:60, 45:55 and 50: 50 water / monomers). As in the previous paragraph was used fotoiniciador Irgacure 819 and probes DMA-2, 3, DMA-2, 4 and DMA-2, 5. The probes were synthesized to be sensitive to both the degree of conversion obtained at every moment, as the composition of the microemulsion polymerised. Process fotocurado adhesives business by irradiation in continuous and pulsed laser light through by inserting probes DMA-TB and DAcOA-TB has done a study of light curing process of formulating trade Loctite 322. First performed by irradiation curing adhesive UV-Vis. The variation of the fluorescence during the reaction has been followed in situ and in real time using low-intensity laser pulses from a laser Nd-YAG as a source of excitation of probes, as detection system has been used an intensified CCD camera. The degree of conversion of adhesives has been obtained by another technique conventional infrared spectroscopy with trasformada Fourier in real time. The conditions of irradiation are reproduced in infrared cavity using a specular reflection accessory that attaches to the optical fiber that leads UV radiation. This would have established correlations between changes in fluorescence and conversion. It should be noted in this case the dramatic increase in the fluorescence emission with the increased stiffness of the medium. Using fluorescence study of the diffusion of water in adhesives. It has carried out monitoring of the process of water absorption sheet of adhesive, Loctite 352, using fluorescent probes inserted into the system. We have evaluated all the probes described in this paper except for DMA-2, 3, because this probe suffers fotoisomerización if it is exposed to light for long periods and in this case the experiment lasted 72 hours. The rest have proved to be suitable for monitoring the process of water absorption. While not experiencing significant movements in the position of the band emission, it suffered a sharp decline in their fluorescence quantum yields. The diffusion coefficients of water in the material have been identified since the measures fluorescence and has been compared to those obtained by gravimetry. The diffusion coefficients calculated from the action emission fluorescence probes DMA-TB and DMA-MR are almost equal to those obtained by the gravimetric method. The values obtained with the other probes are moving away slightly over gravity, but remain within the same order of magnitude. It is important to note that the stickers only absorb about 7% water, so the technique shows an extraordinary sensitivity and precision. These preliminary data show that fluorescence is a very useful technique to assess not only polymerization reactions, but also other processes post-curado involving Lamination of the material. As most relevant conclusions of the work done can be highlighted: 1. The probes are synthesized in order to monitor the reaction of acrylic light curing systems, both in homogeneous and heterogeneous phase, as they show an increase in fluorescence emission along the reaction studied. 2. Of the parameters for monitoring the reactions of light curing have found that the most appropriate, in our case are: the relationship of intensities two lengths ond 8 to l 4ad as probes for DMA-2, 3, DMA-2 , 4 and DMA-2, 5 and the first time for fluorescence probes DMA-TB and DAcOA-TB. 3. The variations of the fluorescence emission permit to study the reaction kinetics light curing and draw conclusions and mecanísticas process in real time. 4. Using the technique of fluorescence, has studied the process of absorbing water and entrecruzados films have been calculated diffusion coefficients associated with the transportation of water, which proved to be very similar to those obtained by conventional technique of gravimetry.

Author: Rubio Romero Noemí.
Year: 2005.
University: RAMÓN LLULL [www.url.edu].
Place of defense: Escuela Técnica Superior IQS.
Place of preparation: Escuela Técnica Superior IQS.

Summary: Two mechanisms are used to explain the cytotoxic effects of the photodynamic action, a photosensitisation process in the presence of oxygen, which are: Type I and Type II mechanisms. Type I mechanism is based on an electron or hydrogen transfer process between the excited photosensitiser and the biosubstrate to yield the reduced and the oxidised forms of the photosensitiser and the substrate, respectively. These species further react and start a free radical chain-type autooxidation process which yields the cytotoxic effect. The Type II mechanism is based of the energy transfer process from the triplet strate of the photosensitiser to molecular oxygen to yield singlet oxygen, the cytotoxic specie in this case. This Thesis is focused on the study of the Type I mechanism of action sinsitised by porphycenes and other porphyrin-like photosensitisers. For this purpose, and as a first step, the photophysical characterisation of potential candidates to be used in applications of the photodynamic action, such as photodynamic therapy of cancer (PDT) and photodynamic inactivation of bacteria (PDI), is performed. Among the studied sensitisers- 2,7,12,17-tetraphenylporphycene (TPPo) and its Pd(II) and Cu(II) complexes (PdTPPo and CuTPPo, respectively), holoboron(III) subnaphtalocyanine (SubNc) and 2,7,12,17-tetrakis(4-butylphenyl)-3,6,13,16-tetraazaporphycene (TAPo)- TPPo, PdTPPo and SubNc are those that show better photophysical properties to be used in PDT and PDI applications. The electron transfer reactivity of the previous compounds is studied in homogeneous organic solutions, in order to characterise the absortion spectra and kinetics of their radical ions. The proton transfer reactivity of TPPo and PdTPPo is also compared with that of TAPo. The study of the interaction of TPPo with several biomolecules shows that this photosensitiser is able to bind several biosubstrates, such as human serum albumin, gramicidin A and lipid A, fact which favours the Type I mechanism. TPPo is also quenched by guanosine, 7,8-dihydro-8-oxoguanosine and phosphatidyl ethanolamine by an electron transfer process. These results show the feasibility of the Type I mechanism of action in photodynamic processes sensitised by these photosensitisers. This is also checked in the photoinactivation studies of E.coli and B. subtilis by TPPo and PdTPPo where the formation of the radical anion of theses photosensitisers is identified. SubNC also shows good photobactericidal activity against E. coli and B. subtilis, and there are several evidences of the formation of its radical anion. All these results show that Type I mechanism plays an important role in the photodynamic processes sensitised by TPPo, PdTPPo and SubNc.

Author: Martínez Junza Víctor.
Year: 2005.
University: RAMÓN LLULL [www.url.edu].
Place of defense: Escuela Técnica Superior IQS.
Place of preparation: Escuela Técnica Superior IQS.

Summary: Laser-Induced Optoacoustic Spectroscopy (LIOAS) is used to study the electrón transfer (ET) processes in three different model systems: 1. the triplet state of the Flavio mononucleotide (FMN) and trytophane and tyrosane, 2. a water soluble porphyrine and benzoquinone and 3. Zn-porphyrine and methylviologen unit linked by two different bridges and included in micelles. LIOAS affords time-resolved thermodynamic profiles from few nanoseconds to microseconds alter photoexcitation as well as the volume changes associated to those processes. Together with other techniques, transient absorption and fluorescente, large information on the ET processes is obtained.

Author: LEO BLASCO EDGAR ABRAHAM.
Year: 2005.
University: POLITÉCNICA DE VALENCIA [www.upv.es].
Place of defense: Dep. Quimica.
Place of preparation: Universidad Politécnica de Valencia.

Summary: This doctoral thesis, entitled "Photochemistry Systems Areno / Olefina", focuses on the field of photochemistry within the discipline of Organic Chemistry. More specifically, the objective of the same has been studying the photochemistry and fotofísica systems bicromofóricos containing a phenol and / or aniline, along with a olefine. This has been accomplished through the synthesis and characterization of the substrates to study. After irradiation of them, identified the products formed, using the usual techniques in the field of chromatography (GC-MS and HPLC), spectroscopy (1H-RMN, 13C-RMN and NOE experiments, IR, UV - visible and fluorescence at steady state and resolved in time). Since finding a common thread between the parties that make up this thesis is complicated, it has opted for the presentation of results for items to facilitate the monitoring of them. The chapters deal with fotogeneración of metiluros of o-quinonas from o-cicloalquenilfenoles, on the characterization of complex intramoleculares NH / derivative of the 2-alilanilina in the ground state and excited on the fotogeneración and reactivity of 1, n-difenil-1, n-azabirradicales, and on improving the reactivity systems polifuncionales OH / NH / through a transfer electrón-protón docked in the excited state. Theoretical calculations have been performed DFT, and that support has allowed explain the mechanisms proposed on the basis of experimental data.

Author: Palacios Cañas Alicia.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: Facultad de Ciencias. U.A.M..
Place of preparation: Departamento de Quimica. Facultad de Ciencias. Universidad Autónoma de Madrid.

Summary: This thesis has been developed ab initio calculations of the ionization multifotónica of simple molecules (H2 + H2) by laser pulses in the region XUV and in the domain of fs and sub-fs. The main objective of this study is to demonstrate the relevance of the inclusion of nuclear motion to analyze the processes of ionization, both dissociative and non-dissociative. In particular, it analyzes the kinetic energy distributions of the nuclei to reveal the effects associated with resonant states vibrónicos intermediate. And finally, it shows a clear dependence on such distributions energy in the process of ionization with the variation in pulse duration and / or intensity of the laser. The states and the continuous linked (both electronic and vibrational) are obtained by expansions in the basic functions B-splines. We work within the dipolar approximation, and to treat the movement of electrons and nuclei, we use approximation Born-Oppenheimer. Have been carried out calculations assuming a regime perturbativo using perturbation theory independent of time, and have been compared with those obtained in a non perturbativo solving the equation Schrà ¶ dinger dependent time. In the case of ion H2 + have been obtained sections effective ionization total and differential (energy protons and electrons) for different photon energies, intensities and durations laser pulse. The resonances barely seen in the fees integrated. Unlike the results in the approximation of fixed nuclei not show differences in the regime perturbativo to resonant energies with intermediate states when the nuclear motion in a proper manner. Predictably, the results do not perturbativos tend to those obtained in the theory of turbulence when the pulse duration increases and the intensity of the laser decreases. We provide the first evidence of strong theoretical resonant effects in the kinetic energy distributions of protons resulting from the explosion Culombiana H2 + by interaction with pulses XUV / fs; resonances reveal the electronic structure of the bound states of the molecule. Moreover, the dominance of the sub-fs, distributions energy protons reveal the initial vibrational state of the system. These results suggest that these energy distributions can be used to characterize wavelengths XUV and pulse durations in the domains of fs and sub-fs. On the other hand, research has been photo-ionization of H2 + by absorbing photons of a few hundred eV. The specter fotoelectrónico reveals effects of interference resulting from the issuance consistent in the presence of two cores, as had been predicted Cohen and Fano. However, we show the limitations of that model to describe correctly the effects of interference observed photon energies high. In the case of the molecule H2 is studied ionization disociativa disociativa and not by interacting with lasers pulsed XUV / fs, including correlation and all degrees of freedom electronic and nuclear weapons. Resolve directly equation Schrà ¶ dinger dependent on the time to obtain the probability of ionization absorption of two, three and four photons for different parameters of the laser. We show that the inclusion of nuclear motion gives rise to a substantial increase in the process of ionization increased resonance (process (1 +1) -REMPI) due to a strong overlap between vibrational states linked. By varying the pulse duration is possible to control the dominant channel (dissociative or not dissociative) in the process of ionization, as well as the distribution of vibrancy in the residual ion. For pulses of the order, or above, the period of vibration of the ground state molecule, disociativa ionization is the dominant channel, which is an unusual situation in studies of photo-ionization. By varying the intensity of laser can be achieved by a similar control channel ionizació 8 No dominates 497 nt, and that an increase in the intensity induced Rabi oscillations between the ground state and excited states of the molecule. These oscillations lead to a "ladder" through which, through successive swings, loaded levels vibrónicos excited that, in principle, inaccessible by absorption of a photon from the ground state. In practice, this mechanism results in an increase in the effective bandwidth of the laser, and therefore a decrease of the effective duration of the pulse.

Author: ABAD FUENTES SERGIO.
Year: 2006.
University: POLITÉCNICA DE VALENCIA [www.upv.es].
Place of defense: Dep. Quimica.
Place of preparation: Universidad Politécnica de Valencia.

Summary: Despite that the search process estereoselectivos in the ground state has focused efforts of numerous investigations over the past few decades, interest in this type of electronic interactions at levels above is relatively recent. This research has focused on interactions estereoselectivas between cromóforos chiral drug of interest, such as acids 2-arilpropiónicos employees as nonsteroidal anti-inflammatory and potential desactivadores chiral their excited states. They are synthesized and studied fotofísicas and photochemical properties of díadas diastereoméricas consisting of hydrogen-giving and ketoprofen, naproxen and giving electrons, as well as bicromóforos diastereoméricos consisting of naproxen and naphthalene in the processes that have been observed in energy transfer and training of excímero. For most of the systems surveyed had obtained considerable estereodiferenciación in the process of deactivation intramolecular of excited states involved.

Author: LANGA MORALES ELISA.
Year: 2006.
University: ZARAGOZA [www.unizar.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: INTRODUCTION It is an indisputable fact that today any type of product to be launched on the market is being subjected to strong quality standards. The regulatory pressure is increased when the product is intended for human consumption, such as food, drugs or cosmetics. The industries that produce used in their processes abundant raw material of plant origin, or their derivatives, including essential oils extracted from certain types of plants, the so-called aromatic and medicinal. The great demand for better quality products has fostered a research work of development and innovation for further extraction and separation processes for a wide variety of these substances. On the other hand, the important requirement of aromatic and medicinal plants along with the implementation of the agricultural policy of the EC has determined that in certain geographic areas has been revitalized its cultivation. Within this context, it could provide for the cultivation of medicinal and aromatic plants as one of the engines that would make possible resurgence of the economy as a region of Aragon, with counties characterized by low rainfall and an accelerating rate of depopulation and deforestation. The potential of this crop is evident in the abundant flora spontaneous aromatic and medicinal there concurs. Its cultivation, in addition to being a real alternative for improving the profitability of these agricultural areas, could contribute to the social setting in rural areas and conservation of the natural environment. To this end, the Center for Food Research and Technology (CITA) within its online research aromatic and medicinal plants, has been developing experimental crops for several years, in order to obtain a high quality raw material for application in the chemical industry, pharmaceuticals and food. In addition to the viability of their crop, in response to agroclimatic conditions, and production field, it is essential to know the economic returns they can generate and that this factor will be critical for these plants represent an alternative to existing crops. Many valuable products from these plants can be obtained by extraction from plant material produced (biomass-based leaves and / or flowers and / or stems). The extraction method is the classic hidrodestilación and in some cases extraction with organic solvents. But recent years have been exploring a new alternative, which is considered in this paper, the extraction with supercritical solvent. The extraction with supercritical fluids (SAI) is an innovative technology that has several advantages over conventional techniques, particularly if used C02 as supercritical fluid. Chief among these is to operate at temperatures close to the environment, so organic compounds termolábiles which decompose in the hidrodestilación remain intact in the supercritical extraction. Faced with the separation with organic solvents, and the products of this technique are completely free of any traces of solvent. Accordingly, the extracts obtained will be more similar to natural product, ie improve their quality. Results from studies of supercritical extraction process (ES) may indicate what conditions are most appropriate for each plant, ie, those that occur in the largest quantities of valuable compounds with the same cost. In turn, these studies may provide relevant information on details for a better design teams separation. With this picture, it is understandable that a crop of plants properly selected, along with a process of disengagement that will ensure effective and product quality, market opens interesting perspectives. In our region there examp. 8 the repr 4cb esentativos export of herbs to other countries, but their number is very low despite good chances. It is obvious that better profitability of natural resources must engarzar optimal production of the plant with a processing industry also best to obtain a final product value. Given the wide field of scientific applications resulting from the use of supercritical fluids (SAI) and changes in the mining and agricultural policy that will affect so sharp to the Community of Aragon in the coming years, the group ...