cg5b00168_si_002.cif (18.07 kB)
Structural Diversity in 1,3-Bis(m‑cyanophenyl)urea
dataset
posted on 2015-05-06, 00:00 authored by Christina
A. Capacci-Daniel, Cameron Mohammadi, Jessica H. Urbelis, Katrina Heyrana, Natasha M. Khatri, Marina A. Solomos, Jennifer A. SwiftHydrogen
bonding between 1,3-bis ureas is a commonly used motif
in the assembly of supramolecular structures such as gels, capsules
and crystals. The title compound, 1,3-bis(m-cyanophenyl)urea
(mCyPU), has previously been shown to crystallize in
both an anhydrous and monohydrate phase (α and H–I).
An expanded search for polymorphs and cocrystals of mCyPU revealed a much greater diversity of solid forms including three
additional polymorphs (β, δ, ε), a second hydrate
(H–II) and two cocrystal phases with dimethyl sulfoxide and
triphenylphosphine oxide. Analysis of the single crystal structures
obtained in this study shows that the typical 1-dimensional H-bonding
between 1,3-bis urea groups is disrupted by the presence of other
H-bond acceptors including cyano, water, sulfoxide and phosphine oxide
functionalities. Re-examination of α-mCyPU additionally
showed both blade and plate-like morphologies could be obtained from
different growth solvents, with crystals of the latter morphology
exhibiting a grain boundary migration prior to melting.