Alkyl Triarylstannanecarbodithioates: Synthesis, Crystal Structures, and Efficiency in RAFT Polymerization

Abstract

Eight alkyl triarylstannanecarbodithioates were synthesized starting from the corresponding triarylstannyl chlorides. They were fully characterized by IR and H, C, and Sn NMR spectroscopy and mass spectrometry. Their solid-state structures and geometric parameters were determined and compared to those of other classes of thiocarbonylthio compounds. These new organotin derivatives are efficient reversible chain-transfer agents for reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene (St) and n-butyl acrylate (BA), with controlled number-average molecular weights and narrow dispersities (Ð<1.3). In some cases, loss of control of the polymerization was evidenced and supported by the observation of side products by Sn NMR spectroscopy. This phenomenon was attributed to the thermal instability of the Sn-RAFT terminal group.

Manganese phosphinocarbodithioate for RAFT polymerisation with sunlight-induced chain end post-treatment

“…To further demonstrate the controlled character of these polymerisations and the integrity of the polymer chain ends, we studied the block copolymerisation of St and n-BA (Table 1, entries [19][20][21][22][23][24]. As was noticed during the homopolymerisations, the chain ends (especially with PSt) may be sensitive to visible light.…”

“…Recently, we identified a new class of triarylstannanecarbodithioate RAFT agents with a tin atom connected to the C=S bond. 19,20 The bulky and strongly electropositive tin atom confers high reactivity on Sn-RAFT agents in St and n-butyl acrylate (n-BA) polymerisations, but at the same time they inhibit the polymerisation of LAMs.…”

Enhanced Control of Phosphinoylcarbodithioate-Mediated RAFT Polymerization: Key Role of Substituents at the Phosphorus Center

“…The efficiency of the title P-RAFT agents was evaluated in the polymerizations of BA and St. , In this study, polymerizations were performed in NMR tubes at 60 °C with azobis­(isobutyronitrile) (AIBN) as thermal initiator and C 6 D 6 as solvent. , 1,4-Dioxane (δ = 3.33 ppm) was used as internal standard for quantitative 1 H NMR analysis of reaction mixtures, whereas triphenyl­phosphine oxide (TPPO, δ = 25.2 ppm) or sulfide (TPPS, δ = 42.1 ppm) was used for 31 P NMR. This methodology was used to evaluate the monomer and RAFT agent transformations over the course of the polymerization.…”

Well-Defined PIII-Terminated Polymers from Phosphorylated Carbodithioate RAFT Agents

“…Several hundreds of these compounds have been developed, and their efficiency in RAFT polymerization has been systematically studied. Nevertheless, each CTA is suitable to control the polymerization of only a narrow range of monomers except for isolated cases like N -methyl- N -(4-pyridinyl) , and N -aryl- N -(4-pyridinyl) dithiocarbamate switchable RAFT agents or CTAs of intermediate reactivity such as O -alkyl xanthates , or pyrazole-based dithiocarbamates. , A few examples of more “exotic” CTAs based on Z-groups involving other elements including heteroelements have also been described: fluorine, selenium, − tin, , or phosphorus. − The introduction of heteroelements with nuclei of half-integer spin allows the use of NMR spectroscopy to study the CTA consumption, kinetics, and mechanisms at the early stages of the polymerization process, as well as for the characterization of the ω-chain-end functionality of the obtained polymers. ,,− …”