RESEARCH

Solid State Photoreactivity

[2+2] photocycloadditions

 Single-crystal-to-single-crystal (SCSC) transformations represent a wonderful mean to understand a solid state reaction evolution, as they link its progress to the crystal structural changes. The [2+2] cycloaddition of cinnamic acids are studied as topochemical model system by X-ray while our approach is to use vibrational spectroscopy (IR and Raman) to understand the mechanism which govern the transformation in the condensed phase. 

References:

  • The impact of solid solution composition on kinetics and mechanism of [2+ 2] photodimerization of cinnamic acid derivatives. L. Pandolfi, A. Giunchi, T. Salzillo, A. Brillante, R.G. Della Valle, E. Venuti, F. Grepioni, S. D'Agostino.CrystEngComm 23 (6), 1352-1359 (2021) 10.1039/D0CE01718C
  • Visualizing a SCSC [2 + 2] photodimerization through its lattice dynamics: an experimental and theoretical investigation. A. Giunchi, L. Pandolfi, T. Salzillo, A. Brillante, R.G. Della Valle, S. d’Agostino, E. Venuti.  10.1002/cphc.202200168

[4+4] photocycloadditions

Photochemical reactions of anthracene derivatives have different mechanism that can be classified as topochemical, non-topochemical or reversible. By means of a micro-Raman technique, we are capable of monitoring, at the same time and on the very same spot, the molecular (intramolecular vibrations or internal motions) and the lattice (intermolecular vibrations or lattice phonons) transformations. Studying the delay between the molecular and the structural changes it is possible to gain information about the reaction path of the different photoreactive systems.

References:

  • Commenting on the photoreactions of anthracene derivatives in the solid state. T. Salzillo, A. Brillante. CrystEngComm 21 (20), 3127-3136 (2019) 10.1039/C9CE00176J
  • Crystal-to-crystal photoinduced reaction of dinitroanthracene to anthraquinone. T. Salzillo, I. Bilotti, R.G. Della Valle, E. Venuti, A. Brillante. Journal of the American Chemical Society 134 (42), 17671-17679 (2012) 10.1021/ja307088n
  • Micro Raman investigation of the photodimerization reaction of 9-cyanoanthracene in the solid state. T. Salzillo, S. Zaccheroni, R.G. Della Valle, E. Venuti, A. Brillante.The Journal of Physical Chemistry C 118 (18), 9628-9635 (2014) 10.1021/jp412484x

Polymorphism and Phase Transitions in Molecular Materials

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References:

  • A New Approach to Polymorphism in Molecular Crystals: Substrate‐Mediated Structures Revealed by Lattice Phonon Dynamics. T. Salzillo, A. Brillante. Advanced Materials Interfaces  9 (28) , 2200815 (2022) 10.1002/admi.202200815
  • Revisiting the Disorder–Order Transition in 1-X-Adamantane Plastic Crystals: Rayleigh Wing, Boson Peak, and Lattice Phonons. T. Salzillo, A. Girlando, A. Brillante. The Journal of Physical Chemistry C 125 (13), 7384–7391 (2021) 10.1021/acs.jpcc.1c00239
  • An alternative strategy to polymorph recognition at work: the emblematic case of coronene. T. Salzillo, A. Giunchi, M. Masino, N. Bedoya-Martı́nez, R. G. Della Valle, A. Brillante, A. Girlando, E. Venuti. Crystal Growth & Design, 18 (9), 4869–4873 (2018) 10.1021/acs.cgd.8b00934

Charge Transfer Complexes

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References:

  • Structure, Stoichiometry, and Charge Transfer in Cocrystals of Perylene with TCNQ-Fx. T. Salzillo, M. Masino, G. Kociok-Köhn, D. Di Nuzzo, E. Venuti, R. G. Della Valle, D. Vanossi, C. Fontanesi, A. Girlando, A. Brillante, E. Da Como. Crystal Growth & Design  16 (5) , 3028-3036 (2016) 10.1021/acs.cgd.5b01663
  • New polymorphs of perylene: tetracyanoquinodimethane charge transfer cocrystals. J. Henderson, M. Masino, L. E. Hatcher, G. Kociok-Köhn, T. Salzillo, A. Brillante, P. R. Raithby, A. Girlando, E. Da Como. Crystal Growth & Design  18 (4), 2003-2009 (2018) 10.1021/acs.cgd.7b01391
  • Solution-processed thin films of a charge transfer complex for ambipolar field-effect transistors. T. Salzillo, A. Campos, M. Mas-Torrent. Journal of Materials Chemistry C, 7 (3), 10257-10263 (2019) 10.1039/C9TC03064F

High Resolution Spectroscopy

Our research activity is in the field of high-resolution infrared and millimetre-wave spectroscopy. In general, the molecules investigated are of astrophysical (HCCCN, NH3,…) or atmospheric (CF2CFH, CH2DF,…) interest. Often, besides the parent species, isotopically substituted molecules are studied. The main goal is their accurate spectroscopic characterization but the study of rare isotopologues is also very useful for the derivation isotopic ratios is different regions of the Space. In fact, such information can shed some light on the evolutionary stage and the physical and chemical properties of those regions.

The infrared spectra are recorded in our laboratory at the industrial chemistry department, while the rotational spectra are recorded at the chemistry department (Ciamician). As far as the far-infrared spectra, they are observed at the synchrotron facilities, either in Paris or in Canada.