Welcome to the Home Page of the

Photochemistry Group

Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica

via Sperone, 31, Vill. S.Agata - 98166 Messina

Phone : +39-090-6765737
Fax : +39-090-259456
E-mail: photochem@chem.unime.it

Description of the Research Themes:

A most important driving force of photochemistry is currently the study of multicomponent (supramolecular) systems. One of the aims leading such studies is the extension of the concept of device (or machine) to the molecular level. A molecular device is an assembly of molecular components (i.e., a supramolecular structure) designed to achieve a specific function. Each molecular component performs one or more single acts, while the entire device performs one or more complex functions, characteristic of the assembly. Molecular devices, like macroscopic ones, need energy to operate. Light is the most convenient form of energy to make molecular devices work. We are interested in designing and constructing photochemical molecular devices (PMDs), i.e., structurally-organized and functionally-integrated systems capable to perform complex functions and powered by light. Since light is made of photons, and photons are at the same time energy quanta and information bits, the PMDs can use light in two different ways: as an energy supply to perform energy-expensive functions (i.e., directional energy transfer, charge separation, conformational changes), and as an input signal to process, store, and retrieve information. The supramolecular systems presently under investigation are:

Luminescent and redox-active nanometer-sized metal complexes: topologically-controlled multicomponent arrays of metal-polypyridine subunits.

Antenna devices: luminescent dendrimers based on transition-metal complexes.

Molecular sensors and switches: host-guest systems containing luminescent moieties.

Luminescent labels: metal complexes immobilized in polymeric matrices for molecular oxygen detection.

The investigated systems are made of a discrete number of selected organic and/or inorganic molecular components, connected by covalent bonds or by other types (hydrogen bond, charge-transfer, etc.) of interaction. They are designed to obtain photoinduced energy or electron migration along predetermined directions and/or to switch on/off a photochemical signal (e.g., luminescence) as a consequence of external inputs (photons, electrons, protons, anions, metal ions, etc.). The properties of these systems are studied by conventional absorption and emission spectroscopy, photochemical methods, time-resolved emission techniques, and electrochemical methods. These systems are interesting both from a fundamental viewpoint (electron- and energy-transfer theories) and for possible applications (energy conversion, analytical labels and sensors, molecular devices).