SupramoleculaSupramolecular polymersr polymers

四川大学化学学院

超分子聚合物超分子聚合物

Introduction to polymer scienceIntroduction to polymer science

Basic of the Supramolecular

Supramolecular polymerSupramolecular polymer A supramolecular polymer is a polymer whose monomer repeat units are held

together by noncovalent bonds.

Non-covalent forces that hold supramolecular polymers together include coordination, π-π interactions, and hydrogen bonding.

OPO OHO

OH2CN

O

N

N H

NN H

HOP OHO

O

O

CH2

N

N

N

O

OP OHOO

O CH2

H

H

O

PO OHO

OH2CN

N

N

N

N

N N

O

CH3

O

HH腺嘌呤

胸腺嘧啶

鸟嘌呤

胞嘧啶

H

Supramolecular polymerSupramolecular polymer

Jean-Marie Lehn

ColloidEarly 20th century

Linear polymerfrom 1930

Supramolecular polymerfrom 1997

Donald J. Cram Charles J. Pedersen

Definition of Supramolecular polymerDefinition of Supramolecular polymer Polymeric arrays of monomeric units that are brought together by reversible and

highly directional secondary interactions, resulting in polymeric properties in dilute and concentrated solutions, as well as in the bulk.

molecular chemistrymolecular chemistryatom + atom → molecular （ covalent ）

supramolecular chemistrysupramolecular chemistrymolecular + molecular → supramolecular

（ noncovalent ）

Intermolecular InteractionsIntermolecular Interactions“Supramolecular Chemistry is the chemistry of the intermolecular bond, concerning the structure and functions of the entities formed by the association of two or more chemical species.” (by Jean-Marie Lehn)Covalent bondC-O bond 340kJ / mol C-C bond 360kJ / molC-H bond 430kJ / mol C=C bond600kJ / molC=O bond 690kJ / molDriving Force for the Formation of Supramolecular Structures Hydrophobic interaction < 40 kJ/molElectrostatic interaction - 20 kJ/molHydrogen bond interaction 12~30 kJ/molVan der Waals interaction 0.4-4 kJ/molCation-π interaction 5-80 kJ/molπ-π interaction 0-50 kJ/molCoordination interaction (Host-guest interaction)

van der Waals Interaction:van der Waals Interaction:Sticky Secrets of the Gecko Sticky Secrets of the Gecko The toes of the gecko have a special adaptation that allows them to adhere to most

surfaces without the use of liquids or surface tension.

the attractive forces that hold geckos to surfaces are van der Waals interactions between the finely divided setae and the surfaces themselves.

Every square millimeter of a gecko's footpad contains about 14,000 hair-like setae. Each seta has a diameter of 5 micrometers.

Hydrophobic interactionHydrophobic interaction Hydrophobic molecules tend to be non-polar and thus prefer other neutral

molecules and non-polar solvents.

Hydrophobic molecules in water often cluster together forming micelles. Water on hydrophobic surfaces will exhibit a high contact angle.

Hydrogen bondHydrogen bond A hydrogen bond is the attractive interaction of a hydrogen atom with an

electronegative atom, like nitrogen, oxygen or fluorine.

The hydrogen must be covalently bonded to another electronegative atom to create the bond.

These bonds can occur between molecules (intermolecularly), or within different parts of a single molecule (intramolecularly).

The Hydrogen bonds can vary in strength from very weak (1-2 kJ/mol) to extremely strong (>155 kJ/mol), Typical values include:

F—H... :F (155 kJ/mol or 40 kcal/mol) O—H... :N (29 kJ/mol or 6.9 kcal/mol) O—H... :O (21 kJ/mol or 5.0 kcal/mol) N—H... :N (13 kJ/mol or 3.1 kcal/mol) N—H... :O (8 kJ/mol or 1.9 kcal/mol)

ππ--π π stackingstacking

π-π stacking are caused by intermolecular overlapping of p-orbitals in π-conjugated systems, so they become stronger as the number of π-electrons increases.

π-π stacking interactions act strongly on flat polycyclic aromatic hydrocarbons such as anthracene, triphenylene, and coronene because of the many delocalized π-electrons.

π-π stacking (aromatic interaction). Weak electrostatic interaction between aromatic rings. There are two general types: face-to-face and edge-to-face:

Face-to-face π-stacking interactions are responsible for the slippery feel of graphite. Similar π-stacking interactions help stabilize DNA double helix.

Face-to-face edge-to-face

Self-assemblySelf-assembly Self-assembly is a term used to describe processes in which a disordered system of

pre-existing components forms an organized structure or pattern as a consequence of specific, local interactions among the components themselves, without external direction. That is without guidance or management from an outside source (other than to provide a suitable environment).

molecule components supramolecular

devicecomponents

Self-assemblySelf-assembly

Self-assembly can be classified as either static or dynamic. In static self-assembly, the ordered state forms as a system approaches equilibrium, reducing its free energy. However in dynamic self-assembly, patterns of pre-existing components organized by specific local interactions are not commonly described as "self-assembled" but "self-organized".

Unit of the Supramolecular

Unit of SupramolecularUnit of Supramolecular

Based on hydrogen-bonding

Based on π-π stacking

Based on coordination (Host-guest)

Based on miscellaneous interactions

Based on hydrogen-bondingBased on hydrogen-bonding

Liquid Crystalline supramolecular developed by Lehn, based on triple hydrogen bonds

Based on hydrogen-bondingBased on hydrogen-bonding

Based on hydrogen-bondingBased on hydrogen-bonding Diblock copolymer

Tautomerization

Homodimerization Heterodimerization

UPy-UPy UPy-Napy1,8-naphthyridineUreidopyrimidinones

Based on π-π stacking Based on π-π stacking

triphenylenes

R = C5H11, C9H19, C11H23, C6H13

R = C3H7CH(CH3)C3H6CH(CH3)2

R = (C2H4O)2CH3

RO

RO

OR

OR

RO OR

Based on π-π stackingBased on π-π stacking

Stacking of Macrocycles via Noncovalent Interaction

a-Hemolysin Heptamera-Hemolysin Heptamer溶血素溶血素

Based on coordinationBased on coordination

NN

R NN

RR

R

NN

R NN

RR

RN

N

R

NN

Ar NN

RR

R

NN

R

CuCu

Cu

+ [Cu(CH3CN)4]+PF6-

Metal IonMetal Ion

PF6-

PF6-

PF6-

Bifunctional metal complexating and its mode of polymerization upon addition of Cu+.

Based on miscellaneous interactionsBased on miscellaneous interactions

Characteristics of the Supramoleculars Characteristics of the Supramoleculars Facile and economic synthesis Self-assembly involves the aggregation of molecules and macromolecules to

thermodynamically stable structures which are held together by weak noncovalent interactions.

Reversibility and Self-repairing Reversible aggregates that can break and recombine on experimental time scalesEnvironmental responsive The noncovalent interactions are sensitive to environment change, such as solvent,

temperature, pH, etc.

Characterization of the Supramolecular

Characterization of the SupramolecularCharacterization of the Supramolecular

Detection of surface:

AFM, SEM, STM, etc.

Characterization of chemical structure

FTIR, 1H-NMR,MS (MALDI-TOF), etc.

Determination of molecular weight

GPC

Representation of viscosity

Ubbelohde viscometer

SPM: SPM: Scanning Probe MicroscopyScanning Probe Microscopy STM: scanning tunneling microscope

tunneling of electrons between probe and surface

AFM: atomic force microscope

measuring of the force on the probe

MFM: magnetic force microscope

AFM with magnetical probe

AFM tip

Detector and Detector and feedback feedback electronicselectronics

Detector and Detector and feedback feedback electronicselectronics

PhotodiodePhotodiode

LaserLaser

Sample SurfaceSample Surface

CantileverCantilever& Tip& Tip

PZT ScannerPZT Scanner

MicroscopyMicroscopy

a) POM (polarizing optical microscopy); b) SEM (Scanning electron microscope);

c) TEM (Transmission Electron Microscope); d) AFM

Investigating the assembly morphology of the supramolecular

11H-NMRH-NMR

MALDI-TOF-MSMALDI-TOF-MS Matrix-assisted laser desorption/ionization (MALDI) is a soft ionization technique

used in mass spectrometry, allowing the analysis of biomolecules (biopolymers such as proteins, peptides and sugars) and large organic molecules (such as polymers, dendrimers and other macromolecules), which tend to be fragile and fragment when ionized by more conventional ionization methods.

The ionization is triggered by a laser beam (normally a nitrogen laser). A matrix is used to protect the biomolecule from being destroyed by direct laser beam and to facilitate vaporization and ionization.

Time of flight (TOF) describes a methods that measure the time that it takes for an object, particle or acoustic, electromagnetic or other wave to travel a distance through a medium.

MALDI-TOF-MS SpectrumMALDI-TOF-MS Spectrum

Application of the Supramolecular

Application of the SupramolecularApplication of the Supramolecular

Molecular tubes for ion channel

作为离子通道的分子管 Liquid crystal materials

液晶材料 Molecular films for separation

用于分离的分子膜 Micro reaction chamber for catalysis

用于催化的微反应器 Drug release and delivery

药物缓释和传递

Preparation of copolymerPreparation of copolymer

Angew. Chem., Intl. Ed. 2004, 43, 6471.

Yang, X. W.; Hua, F. J.; Yamato, K.; Ruckenstein, E.; Gong, B.; Kim, W.; Ryu, C. Y.

NanotubeNanotube

Leibler, L. Nature, 2008, 51, 977–980Aida, T. Nature, 2008, 451, 895–896

Cut Contact for 180 min

Recovery of initial strength

Self-healingSelf-healing