posted on 2021-09-16, 09:13authored byMichelle
B. Mills, Harrison K. S. Young, Gabriele Wehrle, Willem R. Verduyn, Xibo Feng, Paul D. Boyle, Pierre Dechambenoit, Erin R. Johnson, Kathryn E. Preuss
The solid-state structure of neutral
thiazyl radical 4-[2′-(5,6-difluorobenzimidazolyl)]-1,2,3,5-dithiadiazolyl
(F2HbimDTDA) is the result of a combination
of structure-directing intermolecular interactions. Pancake bonding
of radical molecules leads to stacks of [F2HbimDTDA]2 pairs along [100]. Polarization of the DTDA S atoms creates
an area of positive electrostatic potential, forming contacts with
electronegative F atoms of a neighboring molecule to define chains
along [010]. Importantly, the first observation of H-bonding to DTDA
N atoms is reported, with imidazolyl N-H donors. The variety of intermolecular
interactions is similar to that observed in the related HbimDTDA,
but the resulting solid-state structure of the F2HbimDTDA
morphology reported here is quite different. Moreover, computational
analysis of the two structures, using a combination of periodic-boundary
and finite-molecule calculations, has allowed rationalization of the
observed results, indicating that F2HbimDTDA is unlikely
to occur in a morphology comparable to that reported for HbimDTDA
and revealing σ-hole interactions as the determining factor
in the packing of F2HbimDTDA.