The solid-state photoreactivity of 4-aminocinnamic acid (1) and molecular salts [1H]ClO4 and [1H]HSO4 has been investigated, and structural changes have been monitored by X-ray diffraction techniques and FTIR spectroscopy. While the parent compound 1 and its perchlorate salt [1H]ClO4 are photoinert, irradiation of [1H]HSO4 single crystals results in partial single-crystal to single-crystal (SCSC) [2 + 2] photodimerization, with formation of a {[1H]HSO4}0.36·{[12H2][HSO4]2}0.64 solid solution. If crystalline powders of [1H]HSO4 are irradiated, however, the formation of a monomer/dimer solid solution is followed by “extrusion” and recrystallization of both the phodimerization product [12H2]HSO4 and unreacted [1H]HSO4 as nonisomorphous crystal phases. The outcome of the UV irradiation of [1H]HSO4, therefore, is influenced by the crystal size of the reacting monomer and changes dramatically if the irradiated sample is in the form of single macrocrystals or microcrystalline powder.
d’Agostino, S., Boanini, E., Braga, D., Grepioni, F. (2018). Size Matters: [2 + 2] Photoreactivity In Macro- and Microcrystalline Salts of 4-Aminocinnamic Acid. CRYSTAL GROWTH & DESIGN, 18, 2510-2517 [10.1021/acs.cgd.8b00109].
Size Matters: [2 + 2] Photoreactivity In Macro- and Microcrystalline Salts of 4-Aminocinnamic Acid
d’Agostino, Simone
Writing – Original Draft Preparation
;Boanini, ElisaMembro del Collaboration Group
;Braga, DarioMembro del Collaboration Group
;Grepioni, Fabrizia
Supervision
2018
Abstract
The solid-state photoreactivity of 4-aminocinnamic acid (1) and molecular salts [1H]ClO4 and [1H]HSO4 has been investigated, and structural changes have been monitored by X-ray diffraction techniques and FTIR spectroscopy. While the parent compound 1 and its perchlorate salt [1H]ClO4 are photoinert, irradiation of [1H]HSO4 single crystals results in partial single-crystal to single-crystal (SCSC) [2 + 2] photodimerization, with formation of a {[1H]HSO4}0.36·{[12H2][HSO4]2}0.64 solid solution. If crystalline powders of [1H]HSO4 are irradiated, however, the formation of a monomer/dimer solid solution is followed by “extrusion” and recrystallization of both the phodimerization product [12H2]HSO4 and unreacted [1H]HSO4 as nonisomorphous crystal phases. The outcome of the UV irradiation of [1H]HSO4, therefore, is influenced by the crystal size of the reacting monomer and changes dramatically if the irradiated sample is in the form of single macrocrystals or microcrystalline powder.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
