1. Dario Pasini Department of Organic Chemistry University of Pavia, Italy 13 th International IUPAC Conference on Polymers and Organic Chemistry 8 th July 2009 Cyclopolymerization as a Tool for the Synthesis of Functional Macromolecular Materials

2. Outline Cyclopolymers obtained from difunctional acrylic monomers Cyclopolymers obtained from difunctional styrenic monomers Previous work and introduction

3. Mathias, L. J. Trends Polym. Sci. 1996, 10, 330-336. Acar, A. E. et al. Macromolecules 2008, 41, 9019-9024 Difunctional monomers (usually for crosslinking) Efficient Cyclization and Propagation Linear, Soluble Polymers Difunctional monomers (with differing reactivity) Cyclization, Alternation and Propagation Stereochemical control, Steric positioning, Material properties (T g, etc.) Fréchet J. M. J, et al. Chem. Mater. 2001, 13, 4136-4146

4. 2.7 Å Recent Examples 4.6 Å Holmes, A. B. et al. Chem. Commun. 2000, 2419-2420 Prata, J. V. et al. React. Funct. Polym. 2006, 66, 465-470 Endo, T. et al. J. Am. Chem. Soc. 2008, 130, 10832-10833 22-membered rings formed Control achieved using RAFT

5. Cyclopolymers obtained from difunctional acrylic monomers Cyclopolymers obtained from difunctional styrenic monomers Previous work and introduction

6. Inserting Recognition Elements Quaternary centers holding crown ethers orthogonally to the growing chain 61% 80%

7. Gel Permeation 2% AIBN in THF M n = 10600 M w = 17800 DP = 21 2% AIBN in Toluene M n = 20900 M w = 25900 DP = 50 1% AIBN in THF M n = 5900 M w = 15800 DP = 14 2% AIBN in THF M n = 4800 M w = 13400 DP = 12

8. Acqueous Solution of Picrate Salt (10 -2 M) Organic Solution (CHCl 3 ) with carrier (10 -3 M) Distilled H 2 O (Receiving Phase) Transport through a Liquid Membrane Absorbance of receiving Phase (380 nm) measured by UV/Vis vs time With no carrier, no transport occurring

9. Selectivity- Monomer vs Polymer Polymer Monomer Transport Rate (  mol/h) NaKCs Cagnoni, E.; Pasini, D.; Galbiati, A.; Ricci, M.; Righetti, P. P. Macromolecules 2003, 36, 8894-8897 Blazquez, E. ; Mustarelli, P.; Pasini, D.; Righetti, P. P.; Tomasi, C. J. Mater Chem. 2004, 14, 2524-2529

10. Novel D-  -A Chromophores LA = Lewis acid cation (e.g. Ln 3+ ) D. Pasini, P. P. Righetti, V. Rossi Org. Lett. 2002, 4, 23-26. G. Garlaschelli I. Messina, D. Pasini, P. P. Righetti Eur. J. Org. Chem. 2002, 3385-3392. D. Pasini, P. P. Righetti, M. Zema Org. Biomol. Chem. 2004, 2, 1764-1769 Lewis Acid O O OMe OMe N O O MeO MeO N 1 1. LA D--AD--A D-  -A. LA + Eu(OTf) 3 In MeCN 600450  (nm) 300 1.2 2.4 A

11. Supramolecular Chromophore-Supporting Polymers n=1 n=2 n=3 A B Lanthanide ion Complexation D--AD--A C Eu 3+ D--AD--A A OO O O OO O O O O n n Ar R R m D--AD--A 300400500600 (nm) 0.0 0.7 1.4 2.1 3.5 2.8 A Double Chromophores

12. 1 H NMR Characterization 357  (ppm) 1 a b c d e         ’,  ’      Differences between feed and observed ratios (70/30 to 65/35 and 50/50 to 30/70) AIBN (3%) PhCH 3 (0.025 M) AIBN (3%) PhCH 3 (0.25 M) AIBN (3%) PhCH 3 (0.025 M) a b c d e DP=13 DP=58 DP=17-35

13. Eu 3+ Binding 300500700  (nm) 7.5  (x10 -3 ) 22.5 37.5 300500700 8 24 40  (x10 -3 )  (nm) Log K a [Eu(OTf) 3, MeCN] = 3.0 max complex = 480 nm  max complex = 7200 Log K a [Eu(OTf) 3, MeCN] = 2.1 max complex = 480 nm  max complex = 3400 Copolymers have intermediate values C. Coluccini, P. Metrangolo, M. Parachini, D. Pasini, G. Resnati, P. Righetti, J. Polym. Sci. A 2008, 46, 5202-5213.

14. Cyclopolymers obtained from difunctional acrylic monomers Cyclopolymers obtained from difunctional styrenic monomers Previous work and introduction

15. Styrenic Systems Crosslinking 53-65% a) R = Me R’ = Me b) R = Ph R’ = H 40-50%70-80% More flexible Efficient Cyclopolymerization

16. Styrenic systems Cyclopolymerization works efficiently in diluted conditions [M]/ [%AIBN] MnMn MwMw PDIDPYield% 0.01/4----No polymer 0.02/4640082001.3162 (MeOH) 0.04/49600155001.62479 (MeOH) 0.13/413100255001.93230 (MeOH) S. Edizer, B. Veronesi, O. Karahan, V. Aviyente, I. Değirmenci, A. Galbiati, D. Pasini, Macromolecules 2009, 42, 1860-1866 protected deprotected Deprotected polymer crosslinks thermally by the loss of H 2 O at 100°C Polar groups (amphiphilic character)

17. Inefficient cyclization Large extent of crosslinking Introduce steric hindrance M n = 8800 M w = 25800 PD = 2.9 Yield (prec.) =24% All soluble material M n = 6300 M w = 12600 PD = 1.9 Yield (prec.) =64%

18. Controlled Polymerization M:RAFT:AIBNTimePDIMnMn MwMw M n (calcd) Conversion 100:3:1.522 h1.24928711549966974% -22 h1.21979111917----------precipitated 100:6:322 h1.2655257005568487% -22 h1.2459987459------------precipitated Conversion (%) MnMn RAFT RAFT = Gives worse results

19. Towards Alternating Systems Ester cleavage = =

20. Acknowledgments Claudio CornaggiaDr. Arvind Sharma Barbara VeronesiEnrique Blazquez Federica SpiaggiaEmanuela Cagnoni Seda EdizerMarco Parachini Luigi Garlaschelli- Pierpaolo Righetti Alessandro Galbiati (NPT) University of Pavia MIUR PRIN 2004 Fondazione CARIPLO 2007 Regione Lombardia Group website: www.unipv.it/labt

21. Conclusions and Outlook Cyclopolymers obtained from difunctional acrylic monomers Cyclopolymers obtained from difunctional styrenic monomers Why Cyclopolymers? Previous work and applications

22. Easy Organic Functionalization Knoevenagel ReactionBingel reaction Double Alkylation Access to a Variety of Intermediates

23. Fitting the Values. A 1:1 Model R 2 = 0,99 Log K a = 3.8±0.1 + Eu(OTf) 3 in MeCN All spectroscopic titrations are fitted with a 1:1 model.

24. Initiator Good resolution (down to 170 nm) Carbon-rich functionality for Etch Resistance Acid-Labile Protecting Group Polar Functionality for Development Wettability 70% yield M n =5,800 PDI=2.0 A = 0.23 /  PAG: 8% wt Etch: 1.22 vs APEX-E (50 Cl 2 / 150 HBr) Pasini, D.; Low, E.; Fréchet, J. M. J. Adv. Mater. 2000, 12, 347-351 Imaging of a symmetrical cyclopolymer

25. Transport in the Solid State (Li + ) No Tg observed (up to 100°C) Blends of Polymer and PEO (1:1) doped with LiTFSI does not show the expected orders of magnitude increase in conductivity in the solid state M n = 6300 M w = 12600 DP = 15 With Li + Blazquez, E. ; Mustarelli, P.; Pasini, D.; Righetti, P. P.; Tomasi, C. J. Mater Chem. 2004, 14, 2524-2529 At 100°C