Use of Iodocompounds in Radical Polymerization Ghislain David, Cyrille Boyer, Jeff Tonnar, Bruno Ameduri, Patrick Lacroix-Desmazes, and Bernard Boutevin* Laboratoire de Chimie Macromole ´ culaire, UMR (CNRS) 5076, Ecole Nationale Supe ´ rieure de Chimie de Montpellier, 8 rue de l’Ecole Normale, 34296 Montpellier Cedex 5, France Received January 26, 2006 Contents 1. Introduction 3936 2. Synthesis of Iodinated Compounds Used in Radical Polymerization 3937 2.1. Addition of HX onto Monomers 3937 2.2. Addition of Iodine Monochloride onto Fluoroalkenes 3938 2.3. Nucleophilic Substitution 3938 2.4. Structural Requirements of CTAs 3938 2.5. Conclusion 3939 3. Telomerization Reactions 3939 3.1. Initiation and Mechanisms 3940 3.1.1. Redox Catalysis 3940 3.1.2. Thermal Initiation by Telogen Decomposition 3941 3.1.3. Cotelomerization 3941 3.2. Fluoroalkenes Used in Telomerization Reactions 3941 3.2.1. VDF 3941 3.2.2. TFE 3942 3.2.3. CTFE 3942 3.2.4. TrFE 3943 3.2.5. HFP 3943 3.2.6. Other Fluoroalkenes 3944 3.2.7. Cotelomerization 3944 3.3. Conclusion 3944 4. ITP 3945 4.1. Mechanistic Understanding of ITP 3945 4.1.1. Determination of the Transfer Constants 3946 4.1.2. Influence of the Values of the Transfer Constants C T1 and C ex onto Molar Mass and Polydispersity 3947 4.2. Halogenated Monomers Used in ITP 3948 4.2.1. Fluorinated Monomers 3948 4.2.2. Chlorinated Monomers 3949 4.3. Nonhalogenated Monomers Used in ITP 3950 4.3.1. Styrenics 3951 4.3.2. (Meth)acrylates 3952 4.3.3. VAc 3952 4.4. RITP 3952 4.5. Conclusion 3954 5. Applications of Iodinated Compounds 3955 5.1. Synthesis of Fluorinated Oligomers from Iodinated Compounds 3955 5.1.1. Synthesis of New Functional Precursors 3955 5.1.2. Synthesis of New Fluorinated Monomers 3955 5.2. General Applications of Polymers Obtained from Iodinated Precursors 3956 5.3. Conclusion 3958 6. Conclusion 3959 7. List of Symbols and Abbreviations 3959 8. References 3960 1. Introduction Iodocompounds are highly attractive as potential inter- mediates for the synthesis of various organic and macromo- lecular molecules because of the ability of the iodine atom to be a good leaving atom. In addition, they are efficient transfer agents in radical polymerization. In fact, the ability of the iodine atom to transfer onto growing macromolecular chains allowed the development of such compounds. An important class of iodocompounds employed as chain transfer agents (CTAs) are the fluorinated iodocompounds, R F I. These compounds could be obtained in good yield by simple addition of either HI or ICl onto fluorovinylic monomers. These fluorinated CTAs enabled both initiation of the polymerization under UV, thermally or in the presence of redox catalysis, and transfer of the iodine atom onto the growing chains. Oligomers of low molar masses could then be obtained. Then, in the late 1970s, Tatemoto 1 opened the route to the iodine transfer polymerization (ITP). Hence, by using an initiating radical, iodofluorocompounds could enter in a controlled process, based on a degenerative transfer (DT). This real breakthrough was first realized with fluoroolefin monomers but was rapidly extended to other common nonhalogenated vinyl monomers. For specific applications, nonfluorinated CTAs were preferred. Some iodoalkanes, such as iodoform, were then investigated in the ITP process. Recently, reverse iodine transfer polymerization (RITP), another DT process, was discovered by us and is based on the use of molecular iodine. It was thus of interest to deeper summarize the synthesis and the use of iodinated derivatives involved in telomeriza- tion, ITP, and RITP, and these are the objectives of this review, divided in four main parts. The first part reports the syntheses of such iodocompounds, fluorinated and nonfluorinated ones. The structural require- ments are also investigated for further efficient transfer reactions. The following parts describe their uses in several radical processes, i.e., telomerization, ITP, and RITP. A wide range of vinyl monomers (halogenated and nonhalogenated) have been involved in these radical techniques. Then, syntheses of well-architectured copolymers (especially block * To whom correspondence should be addressed. Tel: (0033)4 67 14 43 01. Fax: (0033)4 67 14 72 20. E-mail: bernard.boutevin@enscm.fr. 3936 Chem. Rev. 2006, 106, 3936-3962 10.1021/cr0509612 CCC: $59.00 © 2006 American Chemical Society Published on Web 08/24/2006