chain transfer polymerization (DET-

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1 Supporting information Ambient temperature transition metal-free dissociative electron transfer reversible additionfragmentation chain transfer polymerization (DET- RAFT) of methacrylates, acrylates and styrene Pedro Maximiano, Patrícia V. Mendonça, João R.C. Costa, Naomi L. Haworth, Arménio C. Serra, Tamaz Guliashvili *, Michelle L. Coote * and Jorge F. J. Coelho * CEMUC, Department of Chemical Engineering, University of Coimbra, Coimbra, Portugal ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry, Australian National University, Canberra ACT 2601, Australia

2 Figure SF1. (a) Kinetic plots ln[m]0/[m] vs. time and (b) plot of number-average molecular weights (Mn SEC ) and Ð (Mw/Mn) vs. monomer conversion (the dashed line represents theoretical molecular weight at a given conversion) for the DET-RAFT of MMA at 60 C in DMSO using different [Na2S2O4]0/[CTP]0 ratios. Reaction conditions: [MMA]0/[DMSO] = 2/1 (v/v); [CTP]0/[MMA]0 = 1/222. Figure SF2. (a) Kinetic plots ln[m]0/[m] vs. time and (b) plot of number-average molecular weights (Mn SEC ) and Ð (Mw/Mn) vs. monomer conversion (the dashed line represents theoretical molecular weight at a given conversion) for the DET-RAFT of MMA at 80 C (blue symbols), 60 C (black symbols), 40 C (green symbols) or 30 C (red symbols) in DMSO. Reaction conditions: [MMA]0/[DMSO] = 2/1 (v/v); [MMA]0/[CTP]0/[Na2S2O4]0 = 222/1/1.

3 Figure SF3. (a) Kinetic plots ln[m]0/[m] vs. time and (b) plot of number-average molecular weights (Mn SEC ) and Ð (Mw/Mn) vs. monomer conversion (the dashed line represents theoretical molecular weight at a given conversion) for the DET-RAFT of MMA at 80 C in DMSO using different [Na2S2O4]0/[CTP]0 ratios: 1/1 (blue symbols) and 0.5/1 (red symbols). Reaction conditions: [MMA]0/[DMSO] = 2/1 (v/v); [MMA]0/[CTP]0 = 222/1. Figure SF4. SEC traces (eluent: DMF) of a PGMA sample prepared by DET-RAFT (blue line) and a PMMA standard (green line).

4 Figure SF5. SEC traces (eluent: 0.1M Na2SO4/1 wt % acetic acid/0.02 % NaN3) of a PDPA sample prepared by DET-RAFT (blue line) and a PEG standard red line). Figure SF6. 1 H NMR spectrum (solvent: CDCl3) of a PS sample prepared by DET-RAFT.

5 Figure SF7. 1 H NMR spectrum (solvent: CDCl3) of a PDMAEMA sample prepared by DET- RAFT. Figure SF8. 1 H NMR spectrum (solvent: CDCl3) of a PMMA sample prepared by DET-RAFT.

6 Figure SF9. 1 H NMR spectrum (solvent: CDCl3) of a PDPA sample prepared by DET-RAFT. Figure SF10. 1 H NMR spectrum (solvent: CDCl3) of a PGMA sample prepared by DET-RAFT.

7 Figure SF11. (a) Kinetic plots ln[m]0/[m] vs. time and (b) plot of number-average molecular weights (Mn SEC ) and Ð (Mw/Mn) vs. monomer conversion (the dashed line represents theoretical molecular weight at a given conversion) for the DET-RAFT of MMA at 80 C in DMSO in the ppresence of light (blue symbols) and in the absence of light (red symbols). Reaction conditions: [MMA]0/[DMSO] = 2/1 (v/v); [MMA]0/[CTP]0/[Na2S2O4]0 = 222/1/1. Table ST1. Molecular weight parameters of PMA prepared by DET-RAFT in the presence and absence of light. Conditions: [MA]0/[RAFT agent]0/[na2s2o4]0 = 222/1/1; [MA]0/[CPME] = 2/1 (v/v); T = 30 C; RAFT agent: 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid. Entry Light t (h) Conv. (%) Mn SEC x 10-3 Ð 1 Yes * 1.04 * 2 No * Pure polymer Detailed Theoretical Methodology Systematic conformational searches were performed in the solution phase for the neutral RAFT agent, the radical anion and the radical product to identify their global minimum free energy conformations. For each conformation, geometries were optimized, harmonic vibrational frequencies calculated and absolute energies determined using M05-2X density functional 1 in combination with the 6-31+G* basis sets 2, 3 and the SMD solvation model 4 with DMSO as the

8 solvent. Partition functions and hence entropies and thermal corrections to the energies were calculated using standard textbook formulae for the statistical thermodynamics of an ideal gas under the harmonic oscillator rigid rotor approximation (T = 298 K). Justification for the use of solution phase properties for this purpose can be found in reference 5. Approximate M05-2X solution-phase Gibbs free energies (G soln) could hence be calculated and compared to identify the most stable conformation for each species. The most stable conformation of the radical anion was used as a starting point to locate the transition state for the dissociation. For the calculation of redox potentials, more accurate values of G soln are required. These were obtained using accurate G gas results which were combined with free energies of solvation via standard thermodynamic cycles. Gas phase energies were calculated using a variant of the highlevel composite G3(MP2)-RAD level of theory, 6 where diffuse functions were included to give a better description of anionic species. All geometries were re-optimised using M06-2X 7 /6-31+G* for this purpose and gas phase vibrational frequencies were also calculated. Gas phase partition functions and hence entropies and thermal corrections to the energies were calculated, as described above, and combined with the G3(MP2,+)-RAD energies to give G gas. Free energies of solvation (ΔGsolv) were determined based on the solution phase geometries using SMD with DMSO solvent. It was also important to consider the geometric relaxation associated with solvation; this was approximated as the energy difference between the gas and solution phase geometries, calculated in the gas phase (Erelax). 8, 9 Solution phase free energies could hence be calculated according to equation 1: G soln(298k) = G gas(298k) + ΔGsolv Erelax + ΔG conc (1) where ΔG conc is the phase change correction, 7.93 kj mol To model the electron attachment process, the relevant calculations were performed on the radical anion at the optimised gas and solution phase geometries of the neutral RAFT agent. Translational, rotational and vibrational partition functions were assumed not to be affected by the addition of the electron; however, it was important to employ the appropriate electronic entropy and higher level correction for the anion. The reduction potential of the RAFT agent was calculated according to equation 2: E vs. SHE = -ΔG soln/f - E SHE (2) where the electron convention with Boltzmann statistics was employed, such that the free energy of the electron is kj mol -1 and E SHE in DMSO is V. 11, 12

9 Optimized geometries and energies for all structures investigated in this study are available in Tables S4-5. For all optimizations, vibrational frequencies were inspected to ensure that structures were stationary points of the correct order. T1 diagnostics and spin contamination values were checked where appropriate and found to fall within acceptable limits in all cases. Checks were also performed to ensure the same (lowest energy) electronic state was maintained throughout all calculations for sulfur-containing radicals. All calculations were carried out using either the Gaussian or Molpro , 15 software packages on the NCI National Facility in Canberra, Australia.

10 Table S1. Calculation of reduction potential RAFT agent SO2/SO2 - Gsol(neutral) / Eh Gsol(anion) / Eh Gsol(electron) / Eh ΔGsol(reduction) / Eh ΔGsol(reduction) / kj mol E / V E vs. SHE / V

11 Table S2. Componenents of solution free energy calculations values in Eh unless otherwise specified Species Entropy / J mol -1 K -1 H 298 -H 0 ZPVE HLC E[MP2/ 6-31+G*] E[MP2/ G3MP2Large] E[CCSD(T)/ 6-31+G*] Neutral Radical anion - neutral geometry Radical anion - optimized geometry TS X radical Thioester anion C SO SO2 radical anion Species Eel E 0 H 298 Ggas (298K) Gsolv Erelax [M06- G sol [G3MP2,+,CC] [G3MP2,+,CC] [G3MP2,+,CC] [G3MP2,+,CC] [M05-2X/ 2X/ 6- [G3MP2,+,CC] 6-31+G*] 31+G*] Neutral Radical anion - neutral geometry Radical anion - optimized geometry TS X radical Thioester anion C SO SO2 radical anion (298K)

12 Table S3. (Free) energies of structures along the RAFT agent dissociation pathway relative to the neutral species (kj mol -1 ). Egas G gas G solution (G3MP2) (G3MP2) Esolution (M05-2X) (G3MP2) Neutral RAFT agent Radical anion - neutral geometry Radical anion - optimized geometry Transition State Dissociated products Table S4. Solution Phase Geometries Neutral RAFT agent 1\1\GINC-R93\SP\RM052X\Gen\C13H13N1O2S2\ROOT\30-Jul-2015\0\\# M052X/Ge n 6D SCF=Tight INT(grid=ultrafine) SCRF=(SMD,Solvent=dmso,dovac,self) maxdisk= \\tmp.smd.dmso\\0,1\c,0, , , \S,0, , , \C,0, , , \S,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \N,0, , , \C,0, , , \C,0, , , \C,0, , , \O,0, , , \O,0, , , \ H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \ H,0, , , \H,0, , , \\Version=ES64L-G09RevD.01\State=1-A\HF= \R MSD=6.370e-09\Dipole= , , \Quadrupole= , , , , , \PG=C01 [X( C13H13N1O2S2)]\\@ RAFT agent radical anion 1\1\GINC-R1367\SP\UM052X\Gen\C13H13N1O2S2(1-,2)\ROOT\31-Jul-2015\0\\# M052X/Gen 6D SCF=Tight INT(grid=ultrafine) SCRF=(SMD,Solvent=dmso,dova c,self) maxdisk= \\tmp.smd.dmso\\-1,2\c,0, , , \S,0, , , \C,0, , , \S,0, ,

13 8, \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \N,0, , , \C,0, , , \C,0, , , \C,0, , , \O,0, , , \O,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \\Version=ES64L-G09RevD.01\State=2-A\HF= \S2= \S2-1=0.\S2A= \RMSD=3.489e-09\Dipole= , , \Quadrupole= , , , , , \PG=C01 RAFT agent dissociation TS 1\1\GINC-R92\SP\UM052X\Gen\C13H13N1O2S2(1-,2)\ROOT\30-Jul-2015\0\\# M0 52X/Gen 6D SCF=Tight INT(grid=ultrafine) SCRF=(SMD,Solvent=dmso,dovac, self) maxdisk= \\raftanion-csts.smd.dmso\\-1,2\c,0, , , \S,0, , , \C,0, , , \S,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \N,0, , , \C,0, , , \C,0, , , \C,0, , , \O,0, , , \O,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \\Version=ES64L-G09RevD.01\State=2-A\HF= \S2= \S2-1=0.\S2A= \RMSD=2.814e-09\Dipole= , , \Quadrupole= , , , , , \PG=C01 X radical 1\1\GINC-R89\SP\UM052X\Gen\C6H8N1O2(2)\ROOT\30-Jul-2015\0\\# M052X/Gen 6D SCF=Tight INT(grid=ultrafine) SCRF=(SMD,Solvent=dmso,dovac,self) m

14 axdisk= \\frag2-rad2.smd.dmso\\0,2\c,0, , , \C,0, , , \C,0, , , \N,0, , , \C,0, , , \C,0, , , \C,0, , , \O,0, , , \O,0, , , \H,0, , , \H, 0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \\Version=ES64L-G09RevD.01\State=2-A\HF= \S2= \S2-1=0.\S2A= \RMSD=9.730e-10\Dipole= , , \Quadrupole= , , , , , \PG=C01 Thioester anion 1\1\GINC-R114\SP\RM052X\Gen\C7H5S2(1-)\ROOT\29-Jul-2015\0\\# M052X/Gen 6D SCF=Tight INT(grid=ultrafine) SCRF=(SMD,Solvent=dmso,dovac,self) m axdisk= \\tmp.smd.dmso\\-1,1\s,0, , , \C,0, , , \S,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \C,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \H,0, , , \\Version=ES64L-G09RevD.01\State=1 -A\HF= \RMSD=4.244e-09\Dipole= , , \Quadrupole= , , , , , \PG=C01 [X(C7H5S2)]\\@ SO 2 1\1\GINC-R54\FOpt\RM052X\Gen\O2S1\ROOT\04-Sep-2015\0\\# M052X/Gen 6D S CF=Tight INT(grid=ultrafine) OPT IOP(2/17=4) SCRF=(SMD,Solvent=dmso) m axdisk= \\so2\\0,1\s, ,0., \o, ,0., \O, ,0., \\Version=ES64L-G09 RevD.01\State=1-A1\HF= \RMSD=9.175e-09\RMSF=1.211e-04\Dipol e= ,0., \quadrupole= , , ,0., ,0.\pg=c02v [C2(S1),SGV(O2)]\\@ SO 2 radical anion 1\1\GINC-R45\FOpt\UM052X\Gen\O2S1(1-,2)\ROOT\04-Sep-2015\0\\# M052X/Ge n 6D SCF=Tight INT(grid=ultrafine) OPT IOP(2/17=4) SCRF=(SMD,Solvent=d mso) maxdisk= \\so2anion\\-1,2\s, ,0., \O, ,0., \O, ,0., \\Vers ion=es64l-g09revd.01\state=2-b1\hf= \s2= \s2-1=0.\s2a = \RMSD=2.657e-09\RMSF=3.145e-05\Dipole= ,0., \Quadrupole= , , ,0., ,0.\PG=C02V [C 2(S1),SGV(O2)]\\@

15 Table S5. Gas Phase Geometries Neutral RAFT agent 1\1\GINC-R3155\FOpt\RM062X\Gen\C13H13N1O2S2\ROOT\30-Jul-2015\0\\# M062 X/Gen 6D SCF=Tight INT(grid=ultrafine) OPT IOP(2/17=4) maxdisk= \\RAFT.M062X\\0,1\C, , , \S, , , \C, , , \S, , , \C, , , \C, , , \ C, , , \C, , , \C, , , \C, , , \C, , , \C, , , \N, , , \C, , , \C, , , \C, , , \O, , , \O, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \\Version=ES64L-G09RevD.01\State=1-A\HF= \RMSD=2.778 e-09\rmsf=4.813e-06\dipole= , , \quadrupole = , , , , , \PG=C0 1 [X(C13H13N1O2S2)]\\@ RAFT agent radical anion 1\1\GINC-R1613\FOpt\UM062X\Gen\C13H13N1O2S2(1-,2)\ROOT\21-Jul-2015\0\\ # M062X/Gen 6D SCF=Tight INT(grid=ultrafine) OPT IOP(2/17=4) maxdisk= \\RAFTanion.M062X\\-1,2\C, , , \S, , , \C, , , \S, , , \C, , , \C, , , \C, , , \C, , , \C, , , \C, , , \C, , , \C, , , \N, , , \C, , , \C, , , \C, , , \O, , , \O, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \\Version=ES64L-G09RevD.01\State=2-A\HF= \S2= \S2-1=0.\S2A= \RMSD=4.286e-09\RMSF=8.666e-06\Dipole=1.1

16 168674, , \Quadrupole= , , , , , \PG=C01 RAFT agent dissociation TS 1\1\GINC-R1568\FTS\UM062X\Gen\C13H13N1O2S2(1-,2)\ROOT\21-Jul-2015\0\\# M062X/Gen 6D SCF=Tight INT(grid=ultrafine) OPT=(TS,calcfc,noeigentest,maxcyc=200) IOP(2/17=4) maxdisk= \\raftanion-csts.m062x\\-1, 2\C, , , \S, , , \C, , , \S, , , \C, , , \C, , , \C, , , \C, , , \C, , , \C, , , \C, , , \C, , , \N, , , \C, , , \C, , , \C, , , \O, , , \O, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \\Version=ES64L-G09RevD.0 1\State=2-A\HF= \S2= \S2-1=0.\S2A= \RMSD=7.968 e-09\rmsf=2.515e-06\dipole= , , \quadrupole = , , , , , \PG=C0 1 [X(C13H13N1O2S2)]\\@ X radical 1\1\GINC-R89\FOpt\UM062X\Gen\C6H8N1O2(2)\ROOT\30-Jul-2015\0\\# M062X/G en 6D SCF=Tight INT(grid=ultrafine) OPT IOP(2/17=4) maxdisk= \\frag2-rad2.m062x\\0,2\c, , , \c, , , \C, , , \N, , , \C, , , \C, , , \C, , , \O, , , \O, , , \H, , , \H, , , \ H, , , \H, , , \H, , , \H, , , \H, , , \H, , , \\Version=ES64L-G09RevD.01\ State=2-A\HF= \S2= \S2-1=0.\S2A= \RMSD=6.449e -09\RMSF=3.679e-06\Dipole= , , \Quadrupole= , , , , , \PG=C01 [X (C6H8N1O2)]\\@ Thioester anion 1\1\GINC-R325\FOpt\RM062X\Gen\C7H5S2(1-)\ROOT\23-Jul-2015\0\\# M062X/G

17 en 6D SCF=QC INT(grid=ultrafine) OPT IOP(2/17=4) maxdisk= \\t hioester-an.m062x\\-1,1\s, , , \c, , , \s, , , \c, , , \c, , , \C, , , \C, , , \C, , , \C, , , \H, , , \H, , , \H, , , \H, , , \H, , , \\Version=EM64L-G09R evc.01\state=1-a\hf= \rmsd=0.000e+00\rmsf=1.842e-06\dipole = , , \Quadrupole= , , , , , \PG=C02 SO 2 1\1\GINC-R54\FOpt\RM062X\Gen\O2S1\ROOT\04-Sep-2015\0\\# M062X/Gen 6D S CF=Tight INT(grid=ultrafine) OPT IOP(2/17=4) geom=check guess=read max disk= \\so2\\0,1\s, ,0., \o, ,0., \O, ,0., \\Version=ES64L-G09R evd.01\state=1-a1\hf= \rmsd=3.652e-09\rmsf=1.347e-04\dipole = ,0., \Quadrupole= , , ,0., ,0.\PG=C02V [C2(S1),SGV(O2)]\\@ SO 2 radical anion 1\1\GINC-R45\FOpt\UM062X\Gen\O2S1(1-,2)\ROOT\04-Sep-2015\0\\# M062X/Ge n 6D SCF=Tight INT(grid=ultrafine) OPT IOP(2/17=4) geom=check guess=re ad maxdisk= \\so2anion\\-1,2\s, ,0., \ O, ,0., \O, ,0., \\Version =ES64L-G09RevD.01\State=2-B1\HF= \S2= \S2-1=0.\S2A= \RMSD=5.044e-09\RMSF=9.244e-07\Dipole= ,0., \ Quadrupole= , , ,0., ,0.\PG=C02V [C2( S1),SGV(O2)]\\@ References 1. Y. Zhao, N. E. Schultz and D. G. Truhlar, J. Chem. Theory Comput., 2006, 2, W. J. Hehre, R. Ditchfield and J. A. Pople, J. Chem. Phys., 1972, 56, M. J. Frisch, J. A. Pople and J. S. Binkley, J. Chem. Phys., 1984, 80, A. V. Marenich, C. J. Cramer and D. G. Truhlar, J. Phys. Chem. B, 2009, 113, R. F. Ribeiro, A. V. Marenich, C. J. Cramer and D. G. Truhlar, J. Phys. Chem. B, 2011, 115, D. J. Henry, M. B. Sullivan and L. Radom, J. Chem. Phys., 2003, 118, Y. Zhao and D. G. Truhlar, Theor. Chem. Acc., 2008, 119, J. Ho, A. Klamt and M. L. Coote, J. Phys. Chem. A, 2010, 114,

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