that this ordered structure is generated through intermolecular
H-bonding with the hydrophobic parts of molecules oriented
toward the surface of the layer.
In conclusion, we adopt the approach of supramolecular self-
assembly of an organic gelator containing multiple intermolecular
interactions to prepare a large-scale, orderly-patterned micro-
array. The orderly honeycomb-patterned films could be easily
fabricated by casting a solution of gelator onto solid substrates
followed by evaporation. The atmospheric humidity or substrate
material has no crucial effect on the resulting system. A judicious
thermodynamic balance among the main driving forces for self-
assembly, namely hydrogen bonding, hydrophobic and p...p
interaction, rationalized in terms of the solubility and cooperative
self-assembly of molecules during the process of evaporation was
highlighted. The vesicle model was proposed as the mode of
assembly and proven by SEM, DLS analysis and spectral study.
This approach may open up new possibilities for the preparation
of large-scale, orderly structured materials through the supra-
molecular self-assembly of low mass organic molecules, which will
be extremely useful in a variety of biomedical applications, such
as in DNA chips, protein and cellular microarrays.
Fig. 3 Schematic representation of the mechanism of formation of a regular
pattern; (a) vesicle structure; (b) arrangement of the vesicles in solution, the
red arrow indicates the direction of molecule movement with evaporation;
formation of the porous pattern on (c) the first layer and (d) multilayer.
The IR analysis indicates that ordered hydrogen bonds
between the amide groups in 1 form at temperatures lower than
34.5 1C at CGC. As a result, 1 can gelate solvent to form gel.
Furthermore, from the analysis of the sequence order derived
from 2D IR spectra (Fig. 4c,d, and ESIw), it can be seen that the
sequence order for the formation of the aggregation is as follows:
–CO–CH2–CH2–NH– (H-bonding formation) - cholesteryl
(orderly arrangement) - CH2Cl2 (fluidity prevented) -
This work was supported by NSFC (20771027, 30890141),
NBRPC (2009CB930400), SRFDPHE (200802460007), SSTC
(08JC1402400) and SLADP (B108).
naphthyl (p–p stacking)
- adamantane (intermolecular
Notes and references
space inserted). It is evident that the hydrogen bonding between
amides and the hydrophobic interaction between cholesteryls
play important roles in the formation of the regular aggregation.
The molecular packing of 1 in the xerogel state from CH2Cl2
was further investigated by small angle X-ray scattering and
powder X-ray diffraction (Fig. S6w). The scattering patterns of 1
xerogel show a series of diffraction peaks at 3.03, 1.54, 1.00 nm,
indicating a lamellar structure. Molecular modeling suggested that
the self-assembly of the 1 dimer with a folded conformation had a
length of approximately 3.0 nm. Considering the contribution of
the intermolecular H-bonding, this result supports the assumption
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This journal is The Royal Society of Chemistry 2010
Chem. Commun., 2010, 46, 3553–3555 | 3555