upporting information for All-conjugated, all-crystalline donor-acceptor block copolymers P3HT-b-PNDIT2 via direct arylation polycondensation Fritz Nübling,, Hartmut Komber, Michael ommer,, Makromolekulare Chemie, Universität Freiburg, tefan-meier-traße 31, 79104 Freiburg, Germany Freiburger Materialforschungszentrum, tefan-meier-traße 21, 79104 Freiburg, Germany Leibniz-Institut für Polymerforschung Dresden e.v., Hohe traße 6, 01069 Dresden, Germany Freiburger Institut für interaktive Materialien und bioinspirierte Technologien, Georges- Koehler-Allee 105, 79110 Freiburg, Germany michael.sommer@makro.uni-freiburg.de 1
Materials and yntheses Pd 2 dba 3, Na 2 CO 3 and pivalic acid were purchased from igma-aldrich and used without further purification. Mesitylene was degassed with nitrogen for minimum 20 minutes prior to use. P3HT 1, obtained by Kumada Catalyst-Transfer Polymerization (KCTP), and NDIBr 2,3 2 were synthesized according to literature. tandard procedure for the block copolymer reactions (3c): P3HT-Th 2c (36.5 mg, 5.2 µmol), NDIBr 2 (52.4 mg, 53.2 µmol), bithiophene (8.4 mg, 50.5 µmol), Na 2 CO 3 (17.4 mg, 0.16 mmol), pivalic acid (5.7 mg, 55.8 µmol) and Pd 2 dba 3 (0.5 mg, 0.5 µmol) were added into a screw-cap vial containing a stir bar, evaporated with vacuum and flushed with nitrogen three times in a row. In the same time, mesitylene was degassed with nitrogen for at least 20 minutes and added to the reaction mixture by syringe. Afterwards the vial was sealed with a tight cap and the polymerization was started at 90 C for 72 h. The mixture was cooled down, diluted with chloroform, precipitated into methanol and filtered. The precipitated crude product was further purified by oxhlet extraction with methanol, acetone, ethyl acetate, iso-hexanes, dichloromethane and chloroform, respectively. The obtained chloroform fraction was filtered over io 2 before evaporation the solvent. Instruments NMR pectroscopy. NMR spectra were recorded on a Bruker Avance III 500 spectrometer ( 1 H: 500.13 MHz, 13 C: 125.76 MHz). CDCl 3 (at 30 C) and C 2 D 2 Cl 4 (at 120 C) were used as solvents. The spectra were referenced to the residual solvent peak (CDCl 3 : δ( 1 H) = 7.26 ppm, C 2 D 2 Cl 4 : δ( 1 H) = 5.98 ppm). Gel Permeations Chromatography. GPC measurements of all samples were carried out on four DV gel 5 µm columns with pore sizes ranging from 10 3 to 10 6 Å (Polymer tandards), connected in series with a Knauer K-2301 RI detector and a G1314B UV detector (Agilent Technologies) calibrated with polystyrene standards. CHCl 3 was used as eluent at 22 C with a flow rate of 1.0 ml/min. UV-vis pectroscopy. UV-vis spectra were recorded at 25 C on a UV-1800 eries (himadzu) in chloroform solutions (c = 0.02 mg/ml). Photoluminescence. PL spectra were recorded at 25 C with a HPX-2000 xenon lamp, a Monocan2000 monochromator (Mikropack) and a 2000-FL detector (Ocean Optics) in chloroform solutions (c = 0.02 mg/ml). amples were excited with an argon-ion laser at 450 nm and recorded in a 90 angle to the light source from 465 nm to 900 nm. 2
Matrix-assisted laser desorption/ionization time of flight mass spectrometry. MALDI-ToF M spectra were recorded on an Autoflex III mass spectrometer (Bruker). amples were prepared as 5-10 mg/ml solutions. Differential canning Calorimetry. DC measurements were carried out on a DC eiko 6200 (eiko/perkin Elmer) under nitrogen atmosphere. Heating and cooling rates were between 10 and 20 K/min. The mass of the samples for each measurement was approximately 3-5 mg. PNDIT2 synthesis via DAP: mechanistic insight. intensity/ a.u. 20 6 4 30 min 60 min 120 min 300 min 23 h NDIBr 2 2 0 25 30 35 40 45 elution volume/ ml Figure I-1. GPC analysis of the crude PNDIT2 copolymerization reaction mixture by time. ignal at 42 ml belongs to NDIBr 2 monomer. 3
PNDIT2 synthesis via DAP: linkage of H-P3HT-Mes to NDIBr 2. Figure I-2. 1 H NMR spectra of test reaction of H-P3HT-Mes (2b) and 10 equivalents NDIBr 2. olvent: C 2 D 2 Cl 4 at 120 C. 4
composition/ % 100 80 60 40 20 P3HT-H P3HT-NDI-X P3HT-NDI-P3HT 0 0 200 400 600 800 1000 1200 1400 time/ min Figure I-3. Composition of the product mixture by time calculated from 1 H NMR spectra. 5
Figure I-4. Time dependent progress of covalent linkage between H-P3HT-Mes 2b and 10 equivalents NDIBr 2 analyzed by MALDI-ToF mass spectrometry. 6
End group functionalization of H-P3HT-Br. rr-p3ht-h termination 1 H a rr-p3ht H 2 TT-defect within the chain TT-defect at chain end rr-p3ht Br rr-p3ht 1 Br 1 Th 1 Mes 3 4 5 rr-p3ht 6 7 8 rr-p3ht 1' Br Br rr-p3ht 1' Th 1' Mes 3' 4' 5' rr-p3ht 6' 8' 7' 7
Figure I-5. 1 H NMR spectra (top: aromatic protons region, bottom: aliphatic protons region) of a) pristine H-P3HT-Br (2a) and polymer analogous end group functionalized (uzuki coupling) b) H-P3HT-Mes (2b) and c) H-P3HT-Th (2c). olvent: CDCl 3. # marks signals of 13 C satellites of residual CHCl 3 and of the P3HT backbone signal. 8
BCP syntheses.. 9
Figure I-6. 1 H NMR spectra (top: NDI protons region, bottom: thiophene protons region) of BCPs a) 3a, b) 3b and c) 3c. olvent: C 2 D 2 Cl 4. # marks signals of 13 C satellites of the P3HT backbone signal. Protons c and d could not be identified. The spectra of starting H-P3HT-X (X = Br, Mes or Th) are depicted in Figure I-5 (solvent: CDCl 3 ). 10
Optical properties of BCP 3c. Figure I-7. a) Normalized UV-vis spectra of BCP 3c (black), PNDIT2 (green) and P3HT (red) and b) photoluminescence spectra of H-P3HT-Th 2c (red), P3HT/PNDIT2 blend (blue) and BCP 3c (black). 11
Thermal properties of BCPs made with H-P3HT-Th 2c. Table I-1: Melting (H M ) and crystallization (H C ) enthalpies of H-P3HT-Th 2c, PNDIT2 and BCPs 3c, 4, 5 and 6 estimated by DC. sample P3HT/ wt-% a conversion P3HT-H end group/ % b H-P3HT-Th PNDIT2 H M / J/g c H C / J/g d H M / J/g c H C / J/g d 2c 100-21.6-21.6 - - PNDIT2 - - - 8.7-9.3 3c 33 20 8.6-6.6 1.6-2.0 4 27 40 3.4-3.0 2.3-5 25 70 - - - -2.9 6 37 35 4.9-5.1 - - a Estimated from 1 H NMR integrals of side chain signals at 4.19 ppm (NCH 2 of NDI) and at 2.86 ppm (α-ch 2 of P3HT). b Estimated from 1 H NMR integrals of linkage signal at 7.18 ppm and residual P3HT-H end group signal at 6.94 ppm. c Estimated from 2 nd heating curve. d Estimated from 1 st cooling curve. References (1) Lohwasser, R. H.; Thelakkat, M. Toward Perfect Control of End Groups and Polydispersity in Poly(3-Hexylthiophene) via Catalyst Transfer Polymerization. Macromolecules 2011, 44 (9), 3388 3397 DOI: 10.1021/ma200119s. (2) asikumar, M.; useela, Y. V.; Govindaraju, T. Dibromohydantoin: A Convenient Brominating Reagent for 1,4,5,8-Naphthalenetetracarboxylic Dianhydride. Asian J. Org. Chem. 2013, 2 (9), 779 785 DOI: 10.1002/ajoc.201300088. (3) Kudla, C. J.; Dolfen, D.; chottler, K. J.; Koenen, J.-M.; Breusov, D.; Allard,.; cherf, U. Cyclopentadithiazole-Based Monomers and Alternating Copolymers. Macromolecules 2010, 43 (18), 7864 7867 DOI: 10.1021/ma1014885. 12