Our research interests cover several aspects of the coordination chemistry of transition metal compounds:
- Activation of small molecules and stabilization of otherwise reactive organic cations by early transition metal halides.
“Niobium and tantalum compounds live in the shadow of metal complexes of group 4”
We have contributed to the general, recent progress in the chemistry of niobium and tantalum pentahalides, encouraged by their cheapness, low toxicity associated with the metal element and unconventional reactivity patterns. Organic compounds may undergo unusual activation pathways when allowed to contact with Nb(Ta) pentahalides, made possible by the relatively high metal-halide bond energies. This feature also enables Nb(V) and Ta(V) haloanions to stabilize otherwise reactive organic cations (including the unprecedented stabilization of the benzene radical cation at room temperature in a common organic solvent). The interaction of natural molecules with highly moisture sensitive Nb(Ta) pentahalides might open the doors to unconventional synthetic pathways (making two opposite worlds coming in contact). We are currently interested also in extending the investigation to high valent group 6 metal chlorides (MoCl5, WCl6).
- Synthesis and anticancer activity of ruthenium arene complexes with bioactive fragments.
There are currently considerable ongoing research efforts to develop new, efficient metal-based anticancer agents that overcome the limitations associated with platinum-based drugs, and, in this context, ruthenium-arene complexes have aroused great interest. Based of the idea that the incorporation of organic fragments with known biological functions may improve the drug efficacy, we have been involved with the synthesis and the evaluation of the anticancer activity of new ruthenium complexes containing bioactive fragments, linked to the ruthenium centre through suitable ligands.
- Synthesis and biological activity of highly-functionalized diiron complexes.
Diiron complexes have emerged as interesting scaffolds for the design and the development of new synthetic pathways, due to their capability of mimicking biological systems, the advantages related to the use of a nontoxic and economic metal element, and the opportunities offered by the presence of a couple of adjacent metal centers. An air/water stable diiron system has been developed containing a bridging vinyliminium ligand, that can be selectively functionalized by incorporation of several organic/inorganic groups (e.g. isocyanides, diazocompounds, calchogens, etc.). Some of the resulting complexes exhibit interesting biological behaviour (anticancer activity, controlled CO release upon irradiation). We are currently interested in functionalizing the bridging ligand by introducing suitable bioactive fragments in order to modulate the behaviour of the compounds in the biological environment.
- Transformation of CO2 into valuable compounds by metal carbamates.
Carbon dioxide is an abundant, cheap, nontoxic and therefore appealing C1 building block for synthetic chemistry. Its feasible incorporation into N,N-dialkylcarbamates, i.e. monoanionic oxygen donors of formula (O2CNR2)–, allows the straightforward access to a variety of compounds of general formula M(O2CNR2)n (M = non transition or transition element). We are studying the catalytic behaviour of homoleptic carbamates of non toxic transition metals in organic reactions, aimed to the incorporation of CO2 into valuable chemicals.
Past scientific collaborations (in alphabetical order):
Marco Bortoluzzi (University Cà Foscari of Venezia)
Cinzia Chiappe (University of Pisa)
Federica Chiellini (University of Pisa)
Gianluca Ciancaleoni (University of Pisa)
Marcello Crucianelli (University of L’Aquila)
Paul J. Dyson (École Polytechnique Fédérale de Lausanne)
Claudio Evangelisti (CNR of Milano)
Nicola Ferri (University of Padova)
Tiziana Funaioli (University of Pisa)
Chiara Gabbiani (University of Pisa)
Fabio Piccinelli (University of Verona)
Francesco Pineider (University of Pisa)
Calogero Pinzino (ICCOM-CNR of Pisa)
Anna Maria Raspolli Galletti (University of Pisa)
Timo Repo (University of Helsinki)
James Wilton-Ely (Imperial College, London)
Stefano Zacchini (University of Bologna)
Valerio Zanotti (University of Bologna)