ORGANIC AND HYBRID INORGANIC-ORGANIC MATERIALS WITH INTRIGUING EMISSIVE PROPERTIES IN THE SOLID STATE

ORGANIC AND HYBRID INORGANIC-ORGANIC MATERIALS WITH INTRIGUING EMISSIVE PROPERTIES IN THE SOLID STATE Daniele Malpicci, PhD Thesis, R12760, Università degli Studi di Milano Materials featured by emissive properties in the aggregated form are gaining ever growing attention from the scientific community. In this regard, triimidazo[1,2-a:1',2'-c:1'',2''-e][1,3,5]triazine, TT has recently revealed as an intriguing compound showing, in the solid state, not only intense fluorescence but also room temperature ultralong phosphorescence (RTUP, up to one second) associated with the presence of H aggregates in its crystal structure.[1] The introduction of halogen atoms (Br and I) or chromophoric fragments (2-Fluoropyridine) on the TT scaffold has proven to be a powerful tool to modify both its molecular and solid state photophysical behavior, providing derivatives featured by a complex excitation dependent photoluminescence.[2–5] This PhD thesis work has been devoted to the synthesis and characterization of members of the TT-family by functionalization with different fragments spanning from halogen atoms (Cl[6]) to chromophoric fragments (pyrene,[7,8] pyridine,[9] carbazole). The new derivatives have been photophysically characterized revealing a rich emissive behavior comprising dual fluorescence, molecular phosphorescence and supramolecular room temperature phosphorescence (RTP) in the solid state. Pyrene-substituted TTs have been successfully employed both in the detection of nitroaromatic compounds[10] and in bioimaging.[7] In addition, the properties of TT as a mono-, bi-, and tridentate ligand have been exploited allowing the preparation of one- and three-dimensional (1D, 3D) coordination polymers of Cu(I) and Ag(I) characterized by emission in solid state covering a wide range of UV-Vis spectrum.[11] Finally, TT derivatives functionalized with methylated pyridines or guanidine moieties have been tested as stabilizer for G-Quadruplex structures resulting as promising ligands for such non-canonical DNA folding.[12] [1] E. Lucenti, A. Forni, C. Botta, L. Carlucci, C. Giannini, D. Marinotto, A. Previtali, S. Righetto, E. Cariati, J. Phys. Chem. Lett. 2017, 8, 1894–1898. [2] E. Lucenti, A. Forni, C. Botta, L. Carlucci, C. Giannini, D. Marinotto, A. Pavanello, A. Previtali, S. Righetto, E. Cariati, Angew. Chem. Int. Ed. 2017, 56, 16302–16307. [3] E. Lucenti, A. Forni, C. Botta, L. Carlucci, A. Colombo, C. Giannini, D. Marinotto, A. Previtali, S. Righetto, E. Cariati, ChemPhotoChem 2018, 2, 801–805. [4] A. Previtali, E. Lucenti, A. Forni, L. Mauri, C. Botta, C. Giannini, D. Malpicci, D. Marinotto, S. Righetto, E. Cariati, Molecules 2019, 24, 2552. [5] E. Lucenti, A. Forni, C. Botta, C. Giannini, D. Malpicci, D. Marinotto, A. Previtali, S. Righetto, E. Cariati, Chem. – A Eur. J. 2019, 25, 2452–2456. [6] C. Giannini, A. Forni, D. Malpicci, E. Lucenti, D. Marinotto, A. Previtali, L. Carlucci, E. Cariati, Eur. J. Org. Chem. 2021, 2021, 2041–2049. [7] A. Previtali, W. He, A. Forni, D. Malpicci, E. Lucenti, D. Marinotto, L. Carlucci, P. Mercandelli, M. A. Ortenzi, G. Terraneo, C. Botta, R. T. K. Kwok, J. W. Y. Lam, B. Z. Tang, E. Cariati, Chem. - A Eur. J. 2021, 27, 16690–16700. [8] D. Malpicci, C. Giannini, E. Lucenti, A. Forni, D. Marinotto, E. Cariati, Photochem 2021, 1, 477–487. [9] E. Lucenti, A. Forni, A. Previtali, D. Marinotto, D. Malpicci, S. Righetto, C. Giannini, T. Virgili, P. Kabacinski, L. Ganzer, U. Giovanella, C. Botta, E. Cariati, Chem. Sci. 2020, 11, 7599–7608. [10] M. Formenti, D. Blasi, E. Cariati, L. Carlucci, A. Forni, C. Giannini, M. Guidotti, S. Econdi, D. Malpicci, D. Marinotto, E. Lucenti, Dye. Pigment. 2022, 206, 110637. [11] D. Malpicci, E. Lucenti, A. Forni, D. Marinotto, A. Previtali, L. Carlucci, P. Mercandelli, C. Botta, S. Righetto, E. Cariati, Inorg. Chem. Front. 2021, 8, 1312–1323. [12] D. Malpicci, S. Andolina, S. Di Ciolo, E. Lucenti, E. Cariati, S. Marzano, B. Pagano, J. Amato, A. Randazzo, C. Giannini, European J. Org. Chem. 2022, 2022, DOI 10.1002/ejoc.202200718.