A Synthetic Approach to a Novel Class of Fluorine-Bearing Reversible Addition–Fragmentation Chain Transfer (RAFT) Agents: F-RAFT

Alexander Theis; Martina H. Stenzel; Thomas P. Davis; Michelle L. Coote; Christopher Barner-Kowollik

doi:10.1071/CH05069

RESEARCH ARTICLE

A Synthetic Approach to a Novel Class of Fluorine-Bearing Reversible Addition–Fragmentation Chain Transfer (RAFT) Agents: F-RAFT

Alexander Theis ^A , Martina H. Stenzel ^A , Thomas P. Davis ^A , Michelle L. Coote ^B ^C and Christopher Barner-Kowollik ^A ^C

+ Author Affiliations

- Author Affiliations

^A Centre for Advanced Macromolecular Design, School of Chemical Engineering and Industrial Chemistry, University of New South Wales, Sydney NSW 2052, Australia.

^B Research School of Chemistry, Australian National University, Canberra ACT 0200, Australia.

^C Corresponding authors. Email: camd@unsw.edu.au; mcoote@rsc.anu.edu.au

Australian Journal of Chemistry 58(6) 437-441 https://doi.org/10.1071/CH05069
Submitted: 7 April 2005 Accepted: 3 May 2005 Published: 14 June 2005

Abstract

A synthetic route is described to a novel class of reversible addition–fragmentation chain transfer (RAFT) agents bearing a fluorine Z-group. Such F-RAFT agents are theoretically predicted to allow living free radical polymerization of various monomers without affecting the rate of polymerization, and should also facilitate the construction of block copolymers from monomers with disparate reactivity. The class of F-RAFT agents is exemplified by the example of benzyl fluoro dithioformate (BFDF) in styrene free-radical polymerizations and the process is shown to induce living polymerization.

We gratefully acknowledge financial support from the Australian Research Council in the form of two Discovery Grants to C.B.-K. and M.H.S., as well as to M.L.C. T.P.D. acknowledges receipt of an Australian Professorial Fellowship. M.L.C. also acknowledges generous allocations of computing time on the Compaq Alpha server and the Linux Cluster of the Australian Partnership for Advanced Computing and the Australian National University Supercomputer Facility. We thank Dr Leonie Barner and Mr Istvan Jacenyik for their excellent management of CAMD.

References

^* It should be noted that xanthates and dithiocarbamates can be used to control monomers such as styrene, provided the alkoxy or amino Z-group is designed so as to minimize the resonance stabilization of the C=S bond. For example, xanthates in which the alkoxy group is substituted with strong electron withdrawing groups that reduce the lone pair donating ability of the oxygen (for example, see ref. [12a]) or dithiocarbamates in which the lone pair of the nitrogen in the dithiocarbamates is included as part of an aromatic system (for example, see ref. [12b]), can control styrene. However, when modified in this way, such agents do appear to be suitable for controlling vinyl acetate.

^† Equilibrium constants (353 K, L mol⁻¹) were calculated at the G3(MP2)-RAD//B3-LYP/6-31G(d) level of theory using the standard textbook formulae, based on the statistical thermodynamics of an ideal gas under the rigid-rotor/harmonic oscillator approximation. Full details of the calculations, together with complete geometries in the form of GAUSSIAN archive entries, are provided in the Accessory Material.

A Synthetic Approach to a Novel Class of Fluorine-Bearing Reversible Addition–Fragmentation Chain Transfer (RAFT) Agents: F-RAFT

Abstract

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