Chemistry Reference
In-Depth Information
d
n
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Figure 5.5
A single crystal of compound 16 is grown in an organogel of 15. The
crystal is recovered after gel disruption when adding acetate.
Reprinted with permission from Macmillan Publishers Ltd: Nature
Chemistry (ref. 30), copyright (2010).
The noncovalent interaction of molecular gels and small molecules has been
also explored in the field of crystal growth. For instance, Steed and coworkers
have reported the relevance of gel-small-molecule interactions for the crystal-
lisation of polymorphs of drugs within the matrix of bis(urea) organogels (15)
(Figure 5.5). They have shown that besides the improved quality of the crystals
related to the viscosity effect of the gel medium, differences in polymorphic
preference appeared depending on the gelator and drug structures as well as on
the solvent employed. Additionally, the presence of urea groups responsive to
the addition of anions allowed for the easy recovery of the crystals by simple
addition of tetrabutylammonium acetate.
30
5.3.2 Stabilisation/Activation of Reactive Intermediates and
Protein Structure
Shumburo and Biewer described the use of molecular organogels formed by
compound 17 for the stabilisation of photomerocyanine species (PM) in
