Download Outline

Functional, Nanoscale
Supramolecular Assemblies
Reporter: Sichun Yuan
Supervisor: Prof. Jian Pei
Outline
„
„
„
„
„
„
1. Introduction
2. Formation of supramolecular nanoscale
structure
3. Hydrogen-bond-driven supramolecular
nanoscale assemblies
4. Coordination-driven supramolecular
nanoscale assemblies
5. Functional devices
6. Conclusion
1
1. Introduction
，
Jean-Marie Lehn
Charles. J. Pedersen
Donald-James. Cram
Nobel Prize laureates in 1987
1. Introduction
„
„
Supramolecular chemistry , “chemistry
beyond the molecule,” bearing on the
organized entities of higher complexity that
results from the association of two or more
chemical species held together by
intermolecular forces.
Interdisciplinary field of science covering the
chemical, physical, and biological features of
chemical species.
2
1. Introduction
Angew. Chem. Int. Ed. 1988, 27, 1988
Molecular Recognition
„
„
„
„
Process involving both binding and selective
substrates by a given receptor molecule.
Information storage and read out at supramolecular
level.
Receptor molecule should contain intramolecular
cavity into which the substrate fits, such as
macropolycyclic structure.
Factors effect host-guest interactions: shape and
size of both the host and guest, complementary
binding sites and interaction, and medium.
3
Cation cryptate
= Cs+
Lehn, J.-M. et, al, J. Am. Chem. Soc. 1975, 97, 5022.
Anion cryptate
= Cl-
F. Schmidtchen. et. al, Chem. Commun, 1984, 1115.
2.Formation of Supramolecular
Nanoscale Structures
The self-assembly process mainly includes non-covalent
interactions such as electrostatic, hydrogen-bonding，π-π
stacking, and metal-coordination approaches.
4
The Hydrogen Bond
proton donor X
H
Y
proton acceptor
X, Y = C, N, O, F, P, S, Cl, Se, Br, and I
„
„
„
Strength increase with an increase in the
dipole moment of X-H bond and the electron
lone pair on atom Y.
The thermodynamic stability of H-bonded
complexes dependent on the solvent.
Structural complementary, enthalpy and
entropy effect the end product.
The Jorgensen Model of H-Bond
The stability attributes to attractive and repulsive secondary interaction.
J. Am. Chem. Soc. 1990,112, 2008.
J. Am. Chem. Soc. 1991,113, 2810.
5
Schneider’ s Rule
„
The free energy for dimerization consists only
of two increment: a contribution of 1.88 kcal /
mol for each H-bond and ±0.7 kcal / mol for
each attractive or repulsive secondary
interaction.
Chem. Eur. J. 1996, 2, 1446.
Monomers for H-Bond Assembly
D. S. Lawrence. et. al, Chem. Rev, 1995, 95, 2229.
6
Cyclic Array Based on H-bond
Barr, R. G.; Pinnavaia, T. J. J. Chem. Phys.
1986,90,328.
Lehn, J.-H. Tetrahedron. Lett. 1994, 35, 39.
Supramolecular Cage
Whitesides, G. M. J. Am. Chem. SOC. 1990, 112,6409.
7
Supramolecular Box
Lehn, J.-M. Chem. Commun. 1993, 243.
Gokel, G. W. J. Am. Chem. Soc, 1994, 116, 6089.
Characteristic Features of Thermodynamic
Assembly Mediated by Transition Metals
„
„
„
„
„
„
Coordination bond is highly directional and of
greater strength (10-30Kcal / mol)
Kinetically rapid
Complementary donor and acceptor and maxima
bond number
Reversible thermodynamic equilibrium between
starting materials and products
Proportion of each product is determined by its
thermodynamic stability
Self-correcting and near-quantitative yield
8
Other Self-Assembly Processes
„
„
„
„
„
„
Irreversible self-assembly
Assisted self-assembly
Directed self-assembly
Precursor modification followed by assembly
Self-assembly with post-modification
Self-assembly with intermittent processing.
G. F. Swiegers. et. al, Chem. Rev, 2000, 100, 3483.
Organized Hierarchies in The
Structure of Coordination Compounds
Lehn. J. M. et. al, J. Am. Chem. Soc, 1997, 119, 10956.
Stoddart. J. F. et. al, Acc. Chem. Res, 1997, 30, 393.
9
Motif in Coordination Compounds
Displaying Disperse Structure
„
„
„
„
Latticed motif
Cyclic motif
Filamentous motif
Interlaced motif
Ligands and Metals Used for
Coordination Assembly
10
Latticed Motif
Grid
Lehn, J.-M. et, al, Chem.
Commun. 1997, 2231.
Rack
Lehn, J.-M. et, al, Chem., Int. Ed.
Engl. 1995, 34, 1122.
Ladder
Lehn, J.-M. et, al, Chem. Commun.
1996, 2019.
Cyclic Motif
Design principles:
Stang, P. J. et. al , Chem. Rev. 2000, 100, 853.
11
Chi, X. et. al, Chem. Commun. 1995, 2567.
Lehn, J.-M. et, al, Chem. Eur. J. 1999, 5, 113.
Stang, P. J. et. al. Acc. Chem. Res. 1997, 30, 502.
Stang, P. J. et. al. Organometallics 1997, 16, 3094.
12
Filamentous Motif
Sauvage, J.-P. et. al, J. Am. Chem. Soc. 1996,
118, 11972.
Constable, E. C. Pure Appl. Chem. 1996, 68,
253.
Advances in Inorganic Chemistry, Vol. 46: CA,
1999;
Interlaced Motif
Ring-in-Ring
Michael Schmittel, et. al, Org. Lett., 2002. 4,2289.
Sauvage, J.-P. et. al. J. Am. Chem.
Soc. 1997, 119, 2656.
13
3.Hydrogen-Bond-Driven Supramolecular
Nanoscale Assemblies
„
H-bond modules cooperative other interaction
Edge to face π-πinteraction
Angew. Chem. Int. Ed. 1996, 108, 1628.
3.Hydrogen-Bond-Driven Supramolecular
Nanoscale Assemblies
Rebek. J, J. Am. Chem. Soc, 2000, 122, 7876.
14
Formation of 24 cooperative
hydrogen bonds drives the
spontaneous assembly of a rigid
bifunctional trimelamine
and bis(barbituric acid) to give
selectively the [2 × 2]
hydrogen-bonded grid.
Chem. Commun., 1999, 1311.
Self-Assembled Ionophores by
H-Bonding
Angew. Chem. Int. Ed. 1997, 36, 2068.
15
4. Coordination-Driven Supramolecular
Nanoscale Assemblies
„
„
Nanoscale self-assemblies built using
monodentate ligands
(1) 2D nanoscaffolds
(2) 3D nanoscale architectures (polyhedra)
Nanoscale self-assemblies built from bi- and
tridentate ligands
(1) 2D assemblies (homo- and heteroleptic
aggregation)
(2) 3D (heteroleptic) assemblies
2D Nanoscaffolds
Nanoscale self-Assemblies built using monodentate ligands
A molecular square requires 90° metal corners to
define its specific shape.
16
J. Am. Chem. Soc. 1990,112, 5645.
J. Am. Chem. Soc. 1994,116, 4981.
J. Am. Chem. Soc. 1997,119, 4777.
17
Chem. Commun. 1994, 2313.
J. Am. Chem. Soc. 1999,121, 2741
18
3D Nanoscale Architecture (Polyhedra)
„
„
Induced-fit recognition
Mulitopic ligand, Pd(NO3)2, and end-caped
Pd(Ⅱ) complexes.
J. Am. Chem. Soc. 1995,117, 1649-1650.
19
Chem. Commun. 1998, 1681.
Nanoscale Self-Assemblies Built From
Bidentate and Tridentate Ligands
2,2’-Bipyridines, [1,10]phenanthrolines, catechols and
terpyridines are among the most commonly used chelating
ligands for metallo-supramolecular architectures.
20
Two Different Methods for Assembly
2D Assemblies (Homoleptic Aggregates)
Chem. Commun. 1996, 551
21
Chem. Eur. J. 2004, 10, 1493 .
Angew. Chem. Int. Ed. 2004, 43, 3644.
22
Angew. Chem. Int. Ed. 2004, 43, 3644.
2D Assemblies (Heteroleptic Aggregates)
Angew. Chem. Int. Ed. 1997, 36, 1978.
23
M. Schmittel. et. al, Chem. Commun, 2004, 490.
3D (Heteroleptic) Assemblies
„
„
Linear polytopic ligands, disc-like molecules
or cyclophanes and appropriate metal ions.
The selective heteroleptic preferring to
homoleptic complexation is ascribed to
recognition motif and maximun site
occupancy.
24
Chem. Eur. J, 1999, 5, 1234.
Chem. Commun. 2002, 2566.
25
5. Functional Devices
„
„
„
Structure organized and functionally
integrated system.
Perform function at the molecular and
supramolecular level distinct from each
components.
Components can perform a given function
and suitable for incorporation into an
organized array
5. Functional Devices
„
„
„
5.1 Supramolecular catalysis
5.2 Photoactive assemblies
5.3 Molecular recognition
26
5.1 Supramolecular Catalysis
„
„
„
Container to select reactants by size and shape
Place reactants in adequate distance and geometry
Use allosteric control over catalysis.
Rebek J, Nature, 1996, 382,239.
27
Rebek J, Org. Lett. 2002, 3,327.
Fujita M, Chem. Lett, 2002, 598.
28
Allosteric Supramolecular Catalyst
Roland. Kramer, Chem. Rev, 2004, 104, 3161.
Gianneschi NC, et, al, J. Am. Chem. Soc, 2003, 125, 10508.
29
5.2 Photoactive Assemblies
„
„
„
Light-harvesting
Electron or energy transfer
Photochemical devices
Light Conversion by Energy Transfer
Angew. Chem. Int. Ed. 1987, 26, 266.
30
Light-Harvesting System
Org. Biomol. Chem. 2003, 1, 240.
5.3 Molecular Recognition
„
„
Polygons and polyhedra (defined cavity) suit
for molecular recognition or sensing.
Guest inclusion plays a major role in driving
the equilibrium to a unique entity.
31
Metallosupramolecular Systems
Fujita M, J. Am. Chem. Soc. 2002, 124, 13576.
J. Am. Chem. Soc. 1999, 121, 4296.
32
Angew. Chem. Int. Ed. 2003, 42, 3909.
6. Conclusion
„
„
„
Metal coordination and hydrogen-bond-driven
self-assembly has produced an impressive
variety of startling supramolecular
architecture. The assemblies display
fundamental distinct properties for potential
application.
The synthetically viable path to the rational
design of assemblies is still largely unknown.
H-bond-directed self-assembly in water？
33
6. Conclusion
„
Artificial systems, in size and functional
complexity, are still lagging far behind
biological molecules / entities.
Acknowledgement
„
„
Professor Jian Pei
Xinghua Zhou, Yang Jiang, Jinliang Wang,
Xiaofei Duan, Jia Luo, Jieyu Wang, and other
members in our lab
34
Thank you
for your attention!
35