Details

Autor(en) / Beteiligte

• Stephaniuk, Nadia T
• Nascimento, Mitchell A
• Nikoo, Sahar
• Heyer, Elodie
• Watanabe, Lara K
• Rawson, Jeremy M

Titel

Robust S 4 ⋅⋅⋅O Supramolecular Synthons: Structures of Radical-Radical Cocrystals [p-XC 6 F 4 CNSSN] 2 [TEMPO] (X=F, Cl, Br, I, CN)

Ist Teil von

• Chemistry : a European journal, 2022-03, Vol.28 (15), p.e202103846

Ort / Verlag

Germany

Erscheinungsjahr

2022

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• Cocrystallization of the dithiadiazolyl (DTDA) radicals p-XC F CNSSN (X=F, Cl, Br, I, CN) with TEMPO afforded the 2 : 1 cocrystals [p-XC F CNSSN] [TEMPO] (1-5) whose structures all reflect a common S ⋅⋅⋅O supramolecular motif. The nature of this interaction was probed by DFT calculations (M06/aug-cc-pVDZ) on 1 which revealed that the enthalpy of formation of the [C F CNSSN] [TEMPO] supramolecular motif from [C F CNSSN] and TEMPO is substantial (-54.0 kJ mol ). Electronic structure calculations revealed a TEMPO-based doublet S= configuration as the ground state with limited spin density on the DTDA rings (2.4 %). The corresponding spin quartet state is +78.9 kJ mol higher in energy. An atoms-in-molecules analysis reveals four bond critical points (BCPs) between the TEMPO O and the DTDA S atoms as well as additional BCPs between selected DTDA S atoms and methyl H atoms of the TEMPO molecule. Herein, the structures of 2-5 are considered within the context of a hierarchical view of competing and complementary intermolecular interactions; in particular, the established supramolecular CN⋅⋅⋅S-S synthon is sacrificed in order to form the new S ⋅⋅⋅O interaction.