4th EucheMs chemistry congress

Sunday, 26-Aug 2012 | Monday, 27-Aug 2012
s588
chem. Listy 106, s587–s1425 (2012)
Plenary lectures
Plenary lecture i
P L - 0 1
PerSPeCtiveS in CheMiStry: froM
SuPrAMoLeCuLAr CheMiStry towArdS
AdAPtive CheMiStry
J. M. Lehn 1
1 University of Strasbourg, ISIS, Strasbourg, France
Supramolecular chemistry is actively exploring systems
undergoing self-organization, i.e. systems capable of spontaneously
generating well-defined functional supramolecular architectures
by self-assembly from their components, on the basis of the
molecular information stored in the covalent framework of the
components and read out at the supramolecular level through
specific non-covalent interactional algorithms, thus behaving as
programmed chemical systems.
Supramolecular chemistry is intrinsically a dynamic
chemistry in view of the lability of the interactions connecting the
molecular components of a supramolecular entity and the
resulting ability of supramolecular species to exchange their
components. The same holds for molecular chemistry when the
molecular entity contains covalent bonds that may form and break
reversibility, so as to allow a continuous change in constitution
by reorganization and exchange of building blocks. These features
define a Constitutional Dynamic Chemistry (CDC) covering both
the molecular and supramolecular levels.
CDC introduces a paradigm shift with respect to
constitutionally static chemistry. The latter relies on design for the
generation of a target entity, whereas CDC takes advantage of
dynamic diversity to allow variation and selection. Whereas
self-organization by design strives to achieve full control over the
output molecular or supramolecular entity by explicit
programming, self-organization with selection operates on
dynamic constitutional diversity in response to either internal or
external factors to achieveadaptation.
In the process of reaching higher levels of self-organisation,
CDC gives access to the generation of networks of dynamically
interconverting constituents connected either structurally
(molecular and supramolecular arrays) or reactionnally (set of
connected reactions) or both. They define a class of constitutional
dynamic networks (CDNs), presenting agonistic and antagonistic
relationships between their constituents, that may couple to
thermodynamic or kinetic processes and respond to perturbations
by physical stimuli or to chemical effectors.
These concepts and their implementation in biological
systems as well as in materials science will be described.
The merging of the features:
– information and programmability,
– dynamics and structural diversity,
– constitution and selection, points to the emergence of
adaptive and evolutive chemistry, towards systems of increasing
complexity.
references:
1. Lehn, J.-M., Supramolecular Chemistry: Concepts and
Perspectives, VCH Weinheim, 1995.
2. Lehn, J.-M., Toward complex matter: Supramolecular
chemistry and self-organization, Proc. Natl. Acad. Sci.
USA, 2002, 99, 4763.
3. Lehn, J.-M., From supramolecular chemistry towards
constitutional dynamic chemistry and adaptive chemistry,
Chem. Soc. Rev., 2007, 36, 151.
Plenary lecture ii
4 th EucheMs chemistry congress
P L - 0 2
CAtALySiS At SurfACeS: froM AtoMS to
CoMPLexity
G. ertL 1
1 Fritz-Haber-Institut der Max-Planck-Gesellschaft, Physcal
Chemistry, Berlin, Germany
Catalysis by solid surfaces is, among others, the basis of
chemical industry (such as the Haber-Bosch process for ammonia
synthesis from the elements), as well as of importance for
environmental chemistry (e.g. car exhaust catalyst). Surface
physical techniques enable with single crystals as model systems
elucidation of the underlying elementary processes on atomic
scale. In special cases the rate under continuous flow conditions
may become oscillatory or even chaotic, and the adsorbed species
may form spatio-temporal concentration patterns on mesoscopic
scale. These complex phenomena are manifestations of the
underlying nonlinear dynamics and may be considered as models
for self-organisation in various areas.
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc