Shane O. Mc Donnell, Giuseppe Sforazzini, Johannes K. Sprafke and Harry L. Anderson

Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK harry.anderson@chem.ox.ac.uk

Conjugated Polymers Threaded Conjugated Polymers Threaded Through MacrocyclesThrough Macrocycles

Funding: Regione Sardegna Scholarship, EPSRC and the European Comission (Project THREADMILL – MRTN-CT-2006-036040)

Porphyrin Nanorings and TubesPorphyrin Nanorings and TubesJohannes Sprafke

A Porphyrin Nanoring With A “Sticky” RimA Porphyrin Nanoring With A “Sticky” Rim Formation of Tubular StructuresFormation of Tubular Structures

Recently our group demonstrated the flexibility of conjugated butadiyne linked porphyrin oligomers with the synthesis of a cyclic Octamer1 and a cyclic hexamer2. A template was used to bend linear oligomers, followed by Palladium catalysed ring closure.

Current work is directed towards the synthesis of a derivative of the cyclic hexamer with carboxylic acids on one rim of the ring. These carboxyl groups can be used to bind guests, attach the molecule to surfaces or to form dimers by hydrogen bonding.

A new ring featuring carboxyl groups on both rims is designed to form long tubular structures. Theses tubes will then be used for encapsulation of conjugated polymers or carbon nanotubes.

References: 1M. Hoffmann, H. L. Anderson et al., Angew. Chem. Intl. Ed. 2007, 46, 3122. 2M. Hoffmann, H. L. Anderson et al., submitted.

N

N

N

N Zn

NN

NN

Zn

N

N N

NZn

N

N

N

N

Zn

N

NN

NZn

N NNN Zn

Ar

Ar

Ar

Ar

Ar

OOct

OctO

OH

O

Ar

Ar

Ar

Ar

Bending of Linear Porphyrin WiresBending of Linear Porphyrin Wires

Target Structure

Modification of water-soluble polyrotaxanes1 (PFBP.Liβ CD) has given ‑polyrotaxanes that are soluble in organic solvents such as CHCl3, CH2Cl2, THF and benzene, and free from ionic impurities.2

Organic-Soluble Organic-Soluble PolyrotaxanesPolyrotaxanes

Giuseppe Sforazzini

1Frampton, M. J., Anderson, H. L., Angew. Chem. Int. Ed. 2007, 46, 1028; 2M. J. Frampton, G. Sforazzini, E. Townsend., C. C. Williams, A. Charas, N. S. Kaka, M. Sirish, G. Latini, L. J. Parrott, S. Brovelli, J. S. Wilson, F. Cacialli and H. L. Anderson. Adv. Funct. Mater., manuscript in preparation

conjugated polymer core

— hole transportcyclodextrin insulation

sheath

— electron transport

Molecular MechanicsMolecular MechanicsSynthesis of Non-polar Polyrotaxane Threaded Synthesis of Non-polar Polyrotaxane Threaded Molecuar WiresMolecuar Wires

Calculated structures of polymers. (a) PFBP.Bn, (b) PFBP.Hβ CD (c) ‑PFBP.BnβCD.Bn, (d) PFBP.Meβ CD.Si Minimizations conducted ‑using the MMFFs force field. Solvent: CHCl3 for (a), (c) and (d); water for (b).

Current work is directed toward the synthesis of polyrotaxane insulated molecular wire with a charge-transport shell (a). Incorporation of electron acceptors such as fullerenes (b) should lead to promising photovoltaic materials.

Polyrotaxanes with charge-transporting Polyrotaxanes with charge-transporting substituentssubstituents

Sulfur Functionalised RotaxanesSulfur Functionalised RotaxanesShane Mc DonnellShane Mc Donnell

The versatile polyrotaxane structure allows for simple modification of components. Functionalisation of stopper components with sulfur rich appendages facilitates contact to metal surfaces.

Controlled gold nanoparticle growth leads to tuning of the opto-electronic properties.

Chem. Soc. Rev. 2006, 35, 209

Aurochloric acid is reduced by sodium borohydride and the Au0 species is capped with an SAM of alkane thiols.

J. Chem. Soc. Chem. Commun. 1994, 801

Energy minimised cystamine-[2]rotaxane structure.

TEM of gold nanoparticles. Top dodecane thiol stablised particles. Bottom post ligand exchange with 1 revealed particle diameters that were not significantly modified by reaction conditions.

Measured by Dr. H. Wang, Oxford University.

Synthesis of both naked and encapsulated stilbene units, each containing sulfur appendages.

Left: α-Cyclodexrin. Middle: Chemisorbed 2 on flat Au (111) surface. Right: Using STM and AFM the molecular order and electrical conductivity properties of both 1 and 2 on Au (111) surface are now under way at Samori Group, ULP, Strasbourg.

Molecular OrderingMolecular OrderingSynthesisSynthesis Nanoparticle Assembly Nanoparticle Assembly