Supplementary Material for "Two regioisomeric ladder polymers with a fully conjugated or cross-conjugated polyacene-type skeleton"

Supporting Information: Two regioisomeric ladder polymers with a fully conjugated or cross-conjugated polyacenetype skeleton Marvin T. Unruh1, Guanzhao Wen2, Mischa Bonn2, Silvio Osella3, Hai I. Wang2,4, Ullrich Scherf1 1 Macromolecular Chemistry group (buwmakro) and Wuppertal Center for Smart Materials ans Systems (CM@S), Gauss-Str. 20, D-42119 Wuppertal, Germany, Email: [email protected] 2 Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany; 3 Chemical and Biological Systems Simulation Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland; 4 Nanophotonics, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein1, 3584 CC, Utrecht, the Netherlands General Methods All reactions were carried out in argon atmosphere. The solvents used were of commercial quality (HPLC grade). If necessary, the solvents were dried using common procedures. Unless otherwise indicated, all reagents were obtained from commercial suppliers and were used without further purification. All reactions were carried out under an argon atmosphere by use of standard Schlenk techniques. 1H and 13C NMR spectra were recorded on Bruker Avance 400 or Avance III 600 spectrometers. Gel permeation chromatographic analysis (GPC) utilized PScolumns (two columns, 5 μm gel, pore widths mixed bed linear) connected with UV/Vis and RI detection. All GPC analyses were performed on solutions of the polymers in chloroform at 30 °C (concentration of the polymer: approx. 1.0 g L-1). The calibration was based on polystyrene standards with narrow molecular weight distribution. Monomer Synthesis The monomer syntheses follow known literature procedures described by others and us. G. Zhang, F. Rominger, U. Zschieschang, H. Klauk and M. Mastalerz, Chem. Eur. J. 2016, 22, 14840-14845, https://doi.org/10.1002/chem.201603336. U. Scherf, K. Müllen, Makromol. Chem., Rapid Commun. 1991, 12, 489-497, https://doi.org/10.1002/marc.1991.030120806 U. Scherf, K. Müllen, Polym. Commun. 1992, 33, 2443-2446, https://doi.org/10.1016/00323861(92)90543-6. Polymer Synthesis A) Suzuki-type coupling towards single-stranded precursor polymers P1 and P2 (polyketones) Into a microwave vessel, the corresponding dibromoaryl monomer (2,5-dibromo-4’,4’’-bis-ndecyl-terephthalophenone M2; or 4,6-dibromo-4’,4’’-bis-n-decyl-isophthalophenone M3: 1 eq., 333 mg, 0.459 mmol), the diborylated dihydroanthracene monomer (3,7-di-tert-butyl-9,10dihydroanthracene-1,5-bispinacolatoborate M1: 1 eq., 250 mg, 0.459 mmol), potassium carbonate (5 eq., 317 mg, 2.3 mmol), Aliquat 336 (0.05 eq.), and tetrakis(triphenylphosphine) palladium(0) (0.05 eq., 26.5 mg, 0.023 mmol) were filled in under argon atmosphere. The solids were dissolved in a mixture of toluene (6 mL) and degassed water (3 mL) and stirred at 80 °C for 72 h. Afterwards the solution was cooled down to room temperature, diluted with chloroform and water, and washed with aqueous 2M HCl-solution. The solvents were removed under reduced pressure and the crude polymer was dissolved in a small amount of chloroform. Next, the polymer was precipitated into cold methanol and purified by Soxhlet extraction: (1) methanol, (2) acetone, (3) chloroform. The chloroform fractions were used for the next step. P1 – yield and GPC analysis: Polymer M n [g mol-1] M w [g mol-1] PD DPa Yieldb [mg] Yield [%] P1 12,000 17,400 1,45 14 193 48 a: based on Mn; b: yield of chloroform fraction. 1H NMR spectrum (600 MHz, C2D2Cl4, 353 K) δ = 7.63 – 7.40 (m, 6H), 7.15 – 6.82 (m, 8H), 3.78 (s, 4H), 2.44 (s, 4H), 1.61 – 1.38 (m, 4H), 1.32 – 1.17 (m, 28H), 1.18 – 1.06 (m, 18H), 0.85 (t, J = 6.6 Hz, 9H). 13C NMR spectrum (151 MHz, C2D2Cl4, 353 K) δ = 200.20, 151.33, 144.59, 142.33, 140.25, 139.81, 138.57, 135.22, 133.41, 132.82, 131.27, 128.52, 127.25, 123.59, 39.04, 37.82, 37.33, 35.00, 34.64, 34.42, 33.86, 32.70, 32.65, 32.50, 32.38, 25.75, 17.14. Figure S1: 1H-NMR spectrum of the single-stranded precursor polymer P1 (solvent: C2D2Cl4). Figure S2: 13C-NMR spectrum of the single-stranded precursor polymer P1 (solvent: C2D2Cl4). P2 – yield and GPC analysis: Polymer M n [g mol-1] M w [g mol-1] PD DPa Yieldb [mg] Yield [%] P2 12,500 19,800 1,58 14 205 50 a: based on Mn; b: yield of chloroform fraction. 1H NMR spectrum (600 MHz, C2D2Cl4, 353 K) δ = 7.86 – 7.23 (m, 6H), 7.21 – 6.58 (m, 8H), 3.75 (m, 4H), 2.45 (m, 4H), 1.62 – 0.89 (m, 53H), 0.84 (s, 6H). 13C NMR spectrum (151 MHz, C2D2Cl4, 353 K) δ = 197.04, 148.59, 142.37, 137.17, 135.44, 132.19, 129.89, 128.23, 125.56, 124.24, 120.63, 36.04, 34.37, 32.03, 31.44, 30.91, 29.73, 29.68, 29.57, 29.53, 29.41, 22.78, 14.17 Figure S3: 1H-NMR spectrum of the single-stranded precursor polymer P2 (solvent: C2D2Cl4). Figure S4: 13C-NMR spectrum of the single-stranded precursor polymer P2 (solvent: C2D2Cl4). B) Post-Polymerization Cyclization into PAL 1 and PAL 2 A solution of the single-stranded precursor polymer P1 or P2 (100 mg, 0.128 mmol based on the molecular weight of the repeat unit -P1or half repeat unit -P2- ) and KOt-Bu (127 mg, 1.13 mmol) in DMF (20 mL) was flushed with argon and stirred at 80 °C for 24 h. Then, water was added, and the mixture was extracted with chloroform. The solvents were removed under reduced pressure. The residue was dissolved in a small amount of chloroform. Finally, the ladder polymer was precipitated into cold methanol and dried. PAL1 – yield and GPC analysis: Polymer M n [g mol-1] M w [g mol-1] PD DP Yield [mg] Yield [%] PAL1 11,900 20,000 1,68 15 63 64 1H NMR spectrum (600 MHz, C2D2Cl4, 353 K) δ = 8.93 (s), 8.22 (s), 8.04 (s), 7.64 – 7.42 (m), 2.78 (s), 1.81 (s), 1.59 – 1.34 (m), 1.34 – 1.20 (m), 1.17 – 1.02 (m), 0.98 – 0.83 (m). Recording of a suitable, well-resolved 13C NMR spectrum of PAL 1 with an acceptable signalto-noise ratio was not possible due to solubility limitations. Figure S5: 1H-NMR spectrum of the ladder polymer PAL1 (solvent: C2D2Cl4). Figure S6: IR spectra of the single-stranded precursor polymer P1 (polyketone) and the final ladder polymer PAL1: Please notice the nearly complete disappearance of the carbonyl-related vibrations (red boxes). A very small portion of remaining CO signals may be connected to the occurrence of carbonyl end-groups. PAL2 – yield and GPC analysis: Polymer M n [g mol-1] M w [g mol-1] PD DP Yield [mg] Yield [%] PAL2 11,000 37,800 3,44 14 51 51 1H NMR spectrum (600 MHz, C2D2Cl4, 353 K) δ = 8.77 (s), 8.10 (s), 7.79 (s), 7.31 – 7.05 (m), 2.66 (s), 1.78 – 1.58 (m), 1.56 – 1.02 (m), 0.95 – 0.75 (m). Recording of a suitable, well-resolved 13C NMR spectrum of PAL2 with an acceptable signalto-noise ratio was not possible due to solubility limitations. Figure S7: 1H-NMR spectrum of the ladder polymer PAL2 (solvent: C2D2Cl4). Figure S8: IR spectra of the single-stranded precursor polymer P2 (polyketone) and the final ladder polymer PAL2: Please notice the nearly complete disappearance of the carbonyl-related vibrations (red boxes). A very small portion of remaining CO signals may be connected to the occurrence of carbonyl end-groups. PAL 1 PAL 2 VBM (HOCO) CBM (LUCO) CB (LUCO+1) Figure S9. Frontier Crystal Orbitals for the PAL1 and PAL2 monomer repeating unit forming the polymers considered in this study. The red line indicates the direction of the propagation of the polymer. Terahertz Spectroscopy For the optical pump-THz probe spectroscopy, a commercial Ti: sapphire laser (Spectra Physics Spitfire Ace) was employed as the input light source of the system, which provided the femtosecond (fs) pulsed laser with a repetition rate of 1 kHz, the duration of ~50 fs, and a central wavelength of 800 nm. Then, the fundamental laser was split into three beams, including the THz generation, optical excitation, and electro-optic sampling. The THz generation and detection were achieved based on the optical rectification and free-space electro-optic sampling effect in two different ZnTe crystals. The time-resolved THz photoconductivity was recorded by fixing the sampling beam to the peak of the THz field and varying the delay time between the pump and sampling beam with the motorized delay stage. The optical excitations of different wavelengths were obtained by a commercial optical parametric amplifier from Light Conversion. The measurements were performed in a dry N2-purged environment at room temperature. Drude-Smith model The frequency-resolved photoconductivity shown in maintext can be well described by the Drude-Smith model, [Phys. Rev. B 2017, 96, 205439] a phenomenological model to characterize the charge transport properties in nanostructured semiconductors, like graphene nanoribbons [J. Am. Chem. Soc. 2017, 139, 7982-7988] and semiconducting polymers [Phys. Rev. Lett. 2004, 92, 196601]. 𝜎(𝜔)=𝜔p 2𝜀0𝜏DS 1−𝑖𝜔𝜏DS(1+ 𝑐 1−𝑖𝜔𝜏DS) where τDS, ωp, ε0 represent the charge scattering time, the plasma frequency, and vacuum permittivity, respectively. The c is the backscattering probability ranging from 0 (isotropic scattering) to -1 (100% backscattering).