The Photochemistry Reactivity Group
The Photochemistry Reactivity Group was founded at the University of Valencia in 2013 (GIUV2013-110). However, it took its first steps in 1994 as a very small group in the Faculty of Pharmacy of the University of Valencia, establishing fruitful and lasting collaborations with Prof Miguel Angel Miranda (Polytechnic University of Valencia, Spain) and Prof Pascual Lahuerta (University of Valencia, Spain), and later with Prof Tito Scaiano (University of Ottawa, Canada). The collaborative research focused on two different areas, specifically photochemical reactivity of organic compounds and catalysis promoted by organometallic compounds. In the area of photochemistry, the group studied the photophysical and photochemical behaviours of organic chromophores and bichromophores, energy transfer processes and inter and intra-molecular processes induced by light, as well as the application of chromophores as photocatalysts. In the area of catalysis, the group studied the selectivity of organometallic complexes, mainly dirhodium compounds, in carbene-transfer transformations.
The group gradually increased and was one of the six groups that embarked on the exciting project of forming part of the Institute of Molecular Science (ICMol) of the University of Valencia in 2000, led by Prof Eugenio Coronado. Taking into account the aims of the ICMol and the interdisciplinary expertise acquired by the group, our objectives focused on the synthesis and application of functional photoactive nanoparticles. Our first studies were performed on CdSe quantum dots and gold nanoparticles and were presented at two conferences held in 2007, the XXIII International Conference on Photochemistry (Cologne, Germany) and at the II Jornadas Ibéricas de Fotoquimica (Faro, Portugal). The photochemical size reduction of CdSe and CdSe/ZnS semiconductor nanoparticles assisted by n* aromatic ketones (Journal of the American Society 2009, 131, 892) and the photosensitised seeding of thiolate-stabilised gold nanoparticles (ChemPhysChem 2011, 12, 136) were the first publications of our group at this research stage, in which the group prepared dispersible nanoparticles in aqueous and organic media, studied their optical properties and photostability, modified their shape and size in processes induced by light in the presence or absence of a photocatalyst, and studied synergetic interactions with the organic capping at the nanoparticle surface to create novel chemical sensors.
In recent years, the group has synthesised other types of nanoparticles, such lead halide perovskites, upconversion nanoparticles (lanthanide-based nanoparticles) and gold nanoclusters of interest for biomedical applications. The group reported the first preparation of colloidal lead perovskites (Journal of the American Chemical Society 2014, 136, 850) and demonstrated that bare water-dispersible gold nanoclusters are not luminescent. Up-conversion nanoparticles are of interest for bioimaging, photodynamic therapy, controlled release of drugs, among other applications. Their most outstanding feature is related to their ability to absorb light in the near-IR (greater penetration into tissues) and emit in the visible. The synergic interaction between the nanoparticle and the functional organic capping has led to the preparation of thermo-responsive nanomaterials of interest as nano-thermometers, nanohybrids relevant in photodynamic therapy and fluorescence imaging tracking without therapy, and so on.
The current group’s target is to prepare tailor-made advanced photoactive nanosystems based on these materials and new types of photoactive nanomaterials, such as carbon-based systems, as well as engineering assembly and self-organisation of nanomaterials.
The group is made up of a professors, senior researchers, Ph.D. and graduate students. The research in our laboratory is highly interdisciplinary. The students develop skills in nanomaterial synthesis and characterisation, engineering nanomaterial surfaces with desired ligands aimed at specific applications, and use a wide range of techniques, such as NMR, FTIR, XPS, XRD, TEM, SEM, AFM, UV-NIR absorption and luminescence (steady-state and time-resolved), fluorescence confocal microscopy as well as gaining expertise in photophysics and photochemistry.