Junction‐Controlled Topological Polymerization

Abstract

Methodology that enables the controlled synthesis of linear and branched polymers from an identical monomer will be a novel pathway for polymer synthesis and processing. Herein we first describe the control of one or both of the C(3)‐C(3′) and C(6)‐C(6′) coupling reactions of carbazolyl. In a second approach, an identical monomer containing two carbazolyls is polymerized using chemical and electrochemical oxidizers, leading to topologically controllable growth of linear polymers in weak oxidizer or of cross‐linked polymer chains in strong oxidizer, with satisfactory long chain propagation of step growth polymerization (Mn=6.0×104 g mol−1, Mw/Mn=2.3). This very simple polymerization with cheap reagents and low levels of waste has provided a flexible pathway for synthesis and processing of polymers.

Vertical Step‐Growth Polymerization Driven by Electrochemical Stimuli from an Electrode

“…Thecross-point in Figure 1bis considered to be due to the random measurement points used for UV/Vis spectroscopy,w hereas the good linear relationships in Figure 1d were obtained from statistical measurement of the entire electrode.F urthermore,t opologically controlled nonlinear molecular wires could be possible if both the C3 À C3' and C6ÀC6' carbazole coupling were simultaneously activated at ahigh oxidative potential of ! 1.2 V. [18] CzP(Ru) n in the solid state showed surface-confined nanostructures with only tiny changes in the root-meansquare (RMS) roughness (Figure 3a;see also Figure S13 a), in contrast to af ilm composed of an onspecific random and uniform poly(RuCz 2 ) m (RuCz 2 = Ru II (bda)) complex possessing two pyridine moieties with pendant carbazolyl groups (Figure 3b;s ee also Figure S13 b) with similar surface coverage of Ru units (see Figures S11 and S12). Furthermore,t he electrochemically active surface area (ECSA) [21] of CzP(Ru) n (n = 0and 9) with this special nanostructural orientation was estimated as well as the electrochemical kinetics at the electrode-medium interface.F rom typical scan-rate-dependent CV traces (Figure 4a;s ee also Figure S14), we plotted the capacitive current at 0.05 Vasafunction of scan rate to extract the double-layer capacitance (C DL )from the slopes of fitting lines (Figure 4b).…”

Vertical Step‐Growth Polymerization Driven by Electrochemical Stimuli from an Electrode

“…coupling of carbazolyl groups [17,18] take place at À1.8 and 1.0 Vv s. Ag/Ag + ,r espectively,a nd lead to the formation of asaturated bond (Scheme 1b)and a3,3'-bicarbazole (Scheme 1c). To create avertical molecular wire on the substrate,our design of am olecule for self-assembly and aR uc omplex would have to avoid self-coupling reactions of carbazolyl groups within the SAM on the electrode.…”

“…The molecular wire VP(Ru) n (VP = Ru complex possessing pyridine moieties with pendant vinyl and phosphonic acid groups) with ad ifferent sequence could be obtained on selfassembled VP on an ITO electrode (Figures 1b,d and 2e;see also Figure S10). 1.2 V. [18] CzP(Ru) n in the solid state showed surface-confined nanostructures with only tiny changes in the root-meansquare (RMS) roughness (Figure 3a;see also Figure S13 a), in contrast to af ilm composed of an onspecific random and uniform poly(RuCz 2 ) m (RuCz 2 = Ru II (bda)) complex possessing two pyridine moieties with pendant carbazolyl groups (Figure 3b;s ee also Figure S13 b) with similar surface coverage of Ru units (see Figures S11 and S12). 1.2 V. [18] CzP(Ru) n in the solid state showed surface-confined nanostructures with only tiny changes in the root-meansquare (RMS) roughness (Figure 3a;see also Figure S13 a), in contrast to af ilm composed of an onspecific random and uniform poly(RuCz 2 ) m (RuCz 2 = Ru II (bda)) complex possessing two pyridine moieties with pendant carbazolyl groups (Figure 3b;s ee also Figure S13 b) with similar surface coverage of Ru units (see Figures S11 and S12).…”