Supramolecular porphyrin polymers in solution and at the solid-liquid interface.
We have investigated in detail the self-assembly of a chiral porphyrin trimer in different solvents and correlated this behavior to the aggregation of the molecule at a solid-liquid interface. In n-hexane and cyclohexane, CD spectroscopy and dynamic and static light scattering studies showed that the porphyrin trimer self-assembles already at micromolar concentrations into long, chiral supramolecular polymers, which precipitate as fibers when the solution is drop-cast onto a mica surface. In contrast, in chloroform, the compound is molecularly dissolved up to concentrations of 0.2 mM and when micromolar solutions are drop-cast onto mica, no precipitation of large assemblies occurs. Instead, at the moment that the chloroform film becomes subject to spinodal dewetting and the porphyrin trimers within this film start to self-assemble, extended patterns of equidistant lines of single molecule thick columnar stacks are formed.
van Hameren
Richard
R
Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands.
van Buul
Arend M
AM
Castriciano
Maria A
MA
Villari
Valentina
V
Micali
Norberto
N
Schön
Peter
P
Speller
Sylvia
S
Scolaro
Luigi Monsù
LM
Rowan
Alan E
AE
Elemans
Johannes A A W
JA
Nolte
Roeland J M
RJ