ISMSC 2007 - Università degli Studi di Pavia

PSA 89
Supramolecular assemblies of the crown-containing 2-styrylpyridine with
amino acids.
Labazava I.Ya 1 , Mashura M.M 1 , Gulakova E.N 1 , Fedorov Yu.V 1 , Fedorova O.A 1 , Alfimov M.V 1 ,
J.Saltiel 2 .
1 Photochemistry Center of RAS, 7a Novatorov str, 119421 Moscow, Russia
2 Chemistry Departments, The Florida State University 32306 Tallahassee, Florida
In the present investigation the assemblies of 2-styrylpyridines containing 18-crown-6 and
aza-18-crown-6 ether fragments with perchlorates of amino acids ClO4 - NH3 + (CH2)nCOOH (n=2,
5, 10) were studied by optical methods, mass-spectrometry and NMR- spectroscopy. The
simultaneous binding of ammonium and carboxylate group is required for the recognition of
amino acids. In this work, we selected benzo-18-crown-6 ether as ammonium binding site and
pyridine residue as carboxylate binding site. The two binding centers are connected with each
other through the ethylenic double bond.
N
ClO 4 -
I
O O
H
O O
H H
O O
N+
COOH
COO-
H
H
N
H
+
N + O O
H
O O
O O
IV
ClO 4 -
COO- H
NH 3 +
N +
ClO 4 -
II
O O
O O
O O
N +
O
H
O
O N O
O O
H
+
+
COO- H N
O O
H
O
N
O
O O
H
H
OOC
+
H
H
2ClO -
4
The obtained data showed that complex formation of the crown-containing 2-styrylpyridine
with amino acids occurs through the mono- or ditopic coordination.The irradiation of the
receptor with light results in the reversible reaction of E-Z-isomerization around the double C=C
bond what substantially changes the structure of the receptor. The formation of ditopic complex
influences the E-Z-photoisomerization reaction of the 2-styrylpyridine The occurrence of the
phototransformation will change the ability of the receptor to bind with amino acids
Acknowledgment. The study was supported by CRDF (Grant RUC(2-2656-MO-05)), INTAS
(Grant 03-51-4696), RFBR (06-03-32899 and 05-03-32268), Russian Academy of Sciences and
the Ministry for High Education of Russia.
III
Self-assembly of a guanosine derivative bearing a terthienyl pendant
Stefano Lena a
, Stefano Masiero a
, Silvia Pieraccini a
, Paolo Samorì b
, Gian Piero Spada a
,
Mathieu Surin c
a Dipartimento di Chimica Organica “A. Mangini”, Alma Mater Studiorum - Università di
Bologna, Via S. Giacomo 11, I-40126 Bologna, Italy
b ISIS-ULP, 8, allée Gaspard Monge, F-67083 Strasbourg, France & ISOF-CNR, via Gobetti
101, I-40129 Bologna, Italy
c Service de Chimie des Matériaux Nouveaux, Université de Mons-Hainaut
20, Place du Parc, 7000 Mons, Belgium
Mimicking nature, hierarchical self-assembly provides a tool for bottom-up nanoconstruction of
sophisticated functional architetctures as for the unraveling of complex biological arrangements
and processes, paving the way towards their potential application in the realms of
nanotechnology. We report on the self-assembly of a guanosine derivate bearing an
oligothiophene side group under different environmental conditions. This derivative was found
to spontaneously form, in solution state and on flat surfaces, ordered supramolecolar
nanoribbons, and in the presence of metal cations G-quartet-based aggregates, in which the
individual nucleobases are interacting through H-bonds. The different architectures were
investigated using NMR-2D spettroscopy, small angle X-ray scattering, CD spettroscopy and
scanning probe microscopy. These results are truly important in view of the electronic
properties of these supramolecolar anisotropic architectures and thus for potential applications
in the fields of nano- and opto-electronics [1] .
H 2N
R =
HN
O
O
N
(H 2C)3
N
N
O
H H
H H
O O
S
OR
S
S
C 10H21
[1] Maruccio, G.; Visconti, P.; Arima, V.; D’Amico, S.; Blasco, A.; D’Amone, E.; Cingolani, R.;
Rinaldi, R.; Masiero, S.; Giorgi, T.; Gottarelli, G. Nano Lett. 2003, 3, 479-483.
PSA 90