Tuning On-Surface Synthesis of Graphene Nanoribbons by

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C: Physical Processes in Nanomaterials and Nanostructures

Tuning On-Surface Synthesis of Graphene Nanoribbons by Noncovalent Intermolecular Interactions Meizhuang Liu, Shenwei Chen, Tao Li, Jiaobing Wang, and Dingyong Zhong J. Phys. Chem. C, Just Accepted Manuscript • DOI: 10.1021/acs.jpcc.8b07618 • Publication Date (Web): 09 Oct 2018 Downloaded from http://pubs.acs.org on October 15, 2018

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The Journal of Physical Chemistry

Tuning On-Surface Synthesis of Graphene Nanoribbons by Noncovalent Intermolecular Interactions Meizhuang Liu†, Shenwei Chen†, Tao Li‡, Jiaobing Wang‡, and Dingyong Zhong*,† †

School of Physics and State Key Laboratory for Optoelectronic Materials and Technologies, Sun Yat-sen University, 510275 Guangzhou, China ‡

School of Chemistry, Sun Yat-sen University, 510275 Guangzhou, China

Abstract On-surface synthesis has been widely used for the precise fabrication of surface-supported covalently bonded nanostructures. Here, we report on tuning the on-surface synthesis of graphene nanoribbons by noncovalent intermolecular interactions on Au(111) surfaces. By introducing noncovalent intermolecular interactions

with

intramolecular

the

companion

molecules

cyclodehydrogenation

of

(dianhydride

nonplanar

precursor

derivative), molecules

(bianthryl derivative) are promoted at 200 °C with the monomers interlinked by gold atoms instead of the formation of polyanthrylene. By adjusting the deposition sequence of precursor and companion molecules, conjugated graphene nanoribbons can be finally obtained at a temperature of 240 °C, much lower than the synthesis procedures without companion molecules. Density functional theory calculations indicate that, intermolecular interactions result in a dramatic shrinkage of the torsional angle between the adjacent anthryl groups of the precursor molecule, aiding the cyclodehydrogenation process. Our work demonstrates an intermolecular strategy for controllable fabrication of covalently bonded nanostructures by on-surface synthesis.

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Introduction Graphene naoribbons (GNRs) have an intrinsic band gap originating from one-dimensional quantum confinement, making it a promising semiconducting material.1,2 Two main strategies, namely “top-down” and “bottom-up” approaches, have been developed for the preparation of GNRs.3-5 The bottom-up on-surface synthesis provides a reliable approach for fabrication of GNRs with atomically precise width and edge morphology.6-13 The synthesized GNRs from predefined precursor molecules can allow the precise modulation on the electronic properties of the nanoribbons by different widths and edge orientations, e.g. armchair, zigzag and cove edge structures. Furthermore, molecular design provides an effective strategy for doping in GNRs with chemical substitutions such as nitrogen, sulfur, oxygen, or boron.14-17 Moreover, edge modification with functional groups, formation of heterojunctions, and embedding of nonhexagonal carbon rings have also been developed to change the band gap, modify the band alignment and the local electronic density of states of GNRs.18-23 The feasible tunability of the electronic properties of GNRs makes them more appealing for the potential applications in nanoelectronic and optoelectronic devices.24,25 One of the most extensively studied nanoribbons is 7-AGNR, which is armchair edged with seven carbon atoms across the ribbon width.6,7 The typical two-step reaction of the bottom-up synthesis with the 10,10′-dibromo-9,9′-bianthryl (DBBA) precursor molecules consists of the first thermally activated dehalogenative polymerization at about 200 °C and subsequent cyclodehydrogenation at about 400 °C on metallic surfaces. The surface-assisted cyclodehydrogenation, which can be induced by thermal activation or electrons from the STM tip on coinage metal substrates,26,27 is the key process transforming the staggered polyanthrylene chains into flat, conjugated nanoribbons. The catalytic activity of metal substrates considerably affects the reaction pathways for the DBBA molecules. Instead of 7-AGNRs formed on Au(111) and Ag(111) surfaces, GNRs with chiral (3,1) edges and

nanographenes were

synthesized

on Cu(111)

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and

Cu(110) surfaces,

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respectively.28-30 So far, the on-surface synthesis of GNRs mainly focuses on the monocomponent polymerization of anthracene based precursor molecules. Although it is known that noncovalent intermolecular interactions play a crucial role in the self-assembly of molecular architectures and the formation of functional biological structures,31,32 the effect of noncovalent intermolecular interactions on the on-surface reaction dynamics of GNRs synthesis remains unexplored. Here, we report on tuning the on-surface synthesis of 7-AGNRs by noncovalent intermolecular interactions. We found that noncovalent interactions in a bicomponent molecular assembly can promote intramolecular cyclodehydrogenation of precursor molecules. Organometallic polymers containing gold atoms and bisanthenes, resulting from the intramolecular cyclodehydrogenation of DBBA molecules, are formed on the Au(111) surface at 200 °C. By adjusting the deposition sequence of precursor and companion molecules, the processing temperature for synthesizing conjugated graphene nanoribbons can be significantly decreased in comparison to the monocomponent process without companion molecules. The occurrence of partial cyclodehydrogenated segments in the polyanthrylene chains also unraveled a domino-like reaction process which is initiated at one end of the polyanthracene and then propagates along one side of the polymer chain.

Results and Discussion

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Figure 1. (a) Schematic diagram of the noncovalent intermolecular interactions in the bicomponent system. (b) Different reaction pathways of DBBA precursor molecules with and without the assistance of noncovalent intermolecular interactions on Au(111) surfaces.

1,6,7,12-tetrabromo-3,4,9,10-perylene-tetracarboxylic-dianhydride (Br4-PTCDA) and DBBA precursor molecules were codeposited onto the Au(111) surface. The dissimilar reaction pathways of DBBA molecules on the Au(111) surface with and without the noncovalent intermolecular interactions are sketched in Fig.1. With the assistance of noncovalent intermolecular interactions, bisanthene organometallic polymers can be formed instead of staggered polyanthrylene chains at 200 °C. The organometallic polymers will further convert to conjugated graphene nanoribbons after the cleavage of Au-C bonds and simultaneous cyclodehydrogenation at about 340 °C. In the other reaction pathway, the staggered polyanthrylene chains are first formed by the dehalogenation and polymerization (Ullmann coupling), then transformed to GNRs at 240 °C with the existence of noncovalent intermolecular interactions.

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Figure 2. On-surface synthesis of GNRs with the existence of noncovalent intermolecular interactions. (a) STM image of two types of linear gold-organic polymers alternatively aligned on Au(111) prepared at 200 °C (V = −2.0 V, I = 0.3 nA). (b) High-resolution STM image overlaid with charge density plot related to the highest occupied molecular orbital (V = −0.1 V, I = 1.5 nA). (c) STM image of linear organometallic polymers with partially fused GNR segments (V = −0.1 V, I = 1.0 nA). (d, f) STM images of the valence band (d) and conduction band (f) electronic states of GNRs acquired at negative bias voltage (V = −1.2 V, I = 1.3 nA) and positive bias voltage (V = 0.6 V, I = 1.0 nA). (e,g) The calculated charge density of the valence band (e) and conduction band (g) of GNRs.

The DBBA and Br4-PTCDA molecules were codeposited onto the Au(111) surface. After annealing to 200 °C, the Br4-PTCDA molecules were covalently linked to the linear gold-organic polymers after dehalogenation, as reported in our previous work.21,33 At the same time, the DBBA molecules were converted to the flat bisanthene radicals after the intramolecular cyclodehydrogenation. In comparison, a much higher temperature (>300°C) is required for the cyclodehydrogenation of DBBA molecules without companion molecules.6 The flat geometry of bisanthene radicals leads to a significant steric repulsion between the hydrogen atoms and therefore the C−C bond formation between the radicals is energetically unfavorable. Instead, the radical carbon atoms are interlinked by gold atoms, as observed in our STM images (Fig. 2a-c). As a result, there are two types of the linear gold-organic polymers on the surface. They are arranged alternatively with the intermolecular interactions between the phenylene hydrogen and the anhydride oxygen atoms. The 5 / 17



gold-organic linear polymers tend to align along the three equivalent directions of the Au(111) surface (Fig. 2a). Compared with the large apparent height (0.4 nm) of the staggered polyanthrylene chains, the bisanthene organometallic polymers have a reduced apparent height of 0.16 nm in agreement with the planar configuration after intramolecular cyclodehydrogenation.34 The high resolution STM image (Fig. 2b) also unveils the distribution of local density of states on bisanthene, which is consistent with the calculated highest occupied molecular orbital (HOMO) results (partly overlaid on the STM image). The sample was further annealed to 280 °C, some of the Au-C bonds in bisanthene organometallic polymers were partially cleaved and aryl-aryl coupling took place with simultaneous cyclodehydrogenation, resulting in GNR segments (arrowed in Fig.2c). The fused GNR segments exhibit obvious distinction with the intramolecular features of bisanthene at the same bias voltage (−0.1 V). After annealing to 340 °C, almost all C−Au bonds in bisanthene-Au polymers were cleaved and conjugated GNRs were finally obtained (Fig. 2d and 2f). By using a bromine functionalized STM tip, spatial resolution can be dramatically improved and the valence band (VB) and conduction band (CB) states of AGNRs can be directly imaged. The high-resolution STM images (Fig. 2d and Fig. 2f) acquired at −1.2 V and 0.6 V, respectively, exhibit the dissimilar distribution of electronic states in the nanoribbons, agreeing with the characteristics of the calculated results (Fig. 2e and Fig. 2g). The Tamm states appearing at the zigzag terminus of AGNRs shows a weak dependence on the negative and positive bias voltages (see supporting information Figure S1).35,36

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Figure 3. Synthesis of GNRs from DBBA molecules with/without companion molelcules. (a) STM image of the polyanthrylene chains formed at 200 °C (V = −2.0 V, I = 0.1 nA). (b) STM image of partially cyclodehydrogenated nanoribbons (V = −2.0 V, I = 0.3 nA). (c) STM image of straight GNRs after cyclodehydrogenation at 400 °C (V = −2.0 V, I = 0.1 nA). (d) STM image of the polyanthrylene chains with Br4-PTCDA molecules prepared at 100 °C (V = −2.0 V, I = 0.3 nA). The inset shows different morphological characteristics of the polyanthrylene chains at the positive bias (V = 2.0 V, I = 0.02 nA). (e) STM image of nanoribbon heterojunctions consisting of three types of segments (V = −2.0 V, I = 0.2 nA). (f) STM image of cyclodehydrogenated GNRs obtained at 240 °C with the assistance of PTCDA-Au polymers (V = 1.2 V, I = 0.1 nA).

The above experiment indicates that the intermolecular interactions in the bicomponent system can efficiently alter the on-surface reaction pathway and significantly

reduce

the

temperature

for

activating

cyclodehydrogenation.

Intermolecular interactions can be also introduced after the formation of polyanthrylene chains. In order to compare the cases with/without companion molelcules, we first deposited only DBBA molecules on the Au(111) surface and annealed to different temperatures step by step. The result is shown in Fig. 3a-c. After annealing to 200 °C, polyanthrylene chains were formed by the polymerization of bianthryl radicals (Fig. 3a). The agglomerated polyanthrylene chains can be dragged along the surface by the STM tip (see supporting information Figure S2), indicating a weak interaction between the polymeric chains. As the sample was further annealed to 300 °C, the partially cyclodehydrogenated nanoribbons were synthesized (Fig. 3b). 7 / 17



Some uncoupled anthryl units located on the same side of the polymer axis were observed (arrowed in Fig. 3b). Such partially cyclodehydrogenated structures can serve as intraribbon GNR heterojunctions, in which the unfused and fused segments possess different electronic structures.37 Further annealing to 400 °C, flat 7-GNRs were obtained after the complete cyclodehydrogenation (Fig. 3c). Moreover, the GNRs with wider widths of N=14, 21, 28 and 35 were formed via the interribbon fusion of 7-GNRs at 460 °C (see supporting information Figure S3). These GNRs consist of the subfamily of N=3p, 3p+1, 3p+2 (p is a positive integer), which possess the width-dependent band gaps according to the DFT calculations. The amounts of the fused GNRs decrease with the increasing of the ribbon widths.38 In another experiment, we introduced intermolecular interactions after the formation of polyanthrylene chains. In this way, the formation of bisanthene organometallic polymers is avoided. DBBA molecules were deposited onto the Au(111) surface held at room temperature in advance of Br4-PTCDA molecules. At first, the polyanthrylene chains were formed after the debromination and C−C coupling by annealing to 200 °C. Subsequently, the Br4-PTCDA molecules were deposited onto the surface at 100 °C. The staggered polyanthrylene chains were separated with each other by the Br4-PTCDA molecules in between. The sample exhibited different morphological characteristics at positive and negative bias voltages, as shown in Fig. 3d. With positive biases, a sequence of bright protrusions corresponding to the tilted anthracenes appear alternatively in the polyanthrylene chains (inset in Fig. 3d), with a periodicity of 0.86 nm agreeing with previous work.6 With negative biases, the rodlike characteristic of anthracene units can be distinguished in the STM image. After the sample was further annealed to 200 °C, the nanoribbon heterojunctions consisting of three types of segments were observed (Fig. 3e). The flat GNR segments usually existed at the end of the ribbons while the partially cyclodehydrogenated nanoribbons are located between the flat GNRs and polyanthrylene segments. This phenomenon implies a domino-like reaction: the cyclodehydrogenation prefers to start at the terminals of the polyanthracene chains and then propagates along one side of the polymer chains. Slightly elevating the 8 / 17


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temperature to 240 °C for 30 min, completely cyclodehydrogenated GNRs were obtained with the assistance of noncovalent interactions. Occasionally, partially cyclodehydrogenated segments existed at the positions where the sideward PTCDA-Au polymers were absent, in that cyclodehydrogenation is more difficult without the assistance of noncovalent interactions. In comparison, for the sample with monocomponent DBBA molecules, most polyanthrylene polymers remained after annealing at 240 °C for 30 min (see supporting information Figure S4). Based on the above experiments, we conclude that the noncovalent interactions significantly facilitate the intramolecular cyclodehydrogenation.

Figure 4. DFT calculations. (a,b) Top and side views of the optimized geometric structures of 9,9′-bianthryl monomer. The torsional angle is indicated in the side view of BA monomer. (c,d) Top and side view of BA monomer adsorbed on the Au(111) surface. (e) The Optimized geometry of BA monermer neighbored with PTCDA-Au polymer. (f) Charge difference calculation for BA monomer with PTCDA-Au polymer. The isosurfaces are shown in blue and green colors for the positive and negative value respectively.

We have carried out the DFT calculations to understand the effect of noncovalent intermolecular interactions on the on-surface synthesis of GRNs. We have obtained the optimized geometric structures of 9,9′-bianthryl (BA) monomer in different situations: an isolated monomer (Fig. 4a), a monomer adsorbed on Au(111) surface (Fig. 4c), and a monomer neighbored with PTCDA-Au polymer (Fig. 4e). The BA monomer adopts a staggered configuration due to the steric hindrance between neighboring anthracene units, weakening the catalytic effect of the Au surface and 9 / 17



consequently slowing down the cyclodehydrogenation reaction.27 We compared the torsional angles between the planes of neighboring anthracene units. For the BA monomer adsorbed on the Au(111) surface, the torsional angle is slightly reduced from 80° (Fig. 4b) to 75° (Fig. 4d). Interestingly, the torsional angle can be decreased from 80° to 66° due to the noncovalent interaction with the neighboring PTCDA-Au polymer (Fig. 4f), making the hydrogen atoms at opposing carbon sites closer to each other. Compared with the total energy of the isolated BA monomer, there is an increased energy of 0.17 eV for the geometric structures of BA monomer due to the decrease of the torsional angles. But the interaction between the BA monomer and the PTCDA-Au polymer is strong enough, which was calculated to be 0.76 eV. The hydrogen bonding also leads to a charge transfer within the BA monomer confirmed by the charge difference calculations, which might contribute to the promotion of the cyclodehydrogenation process. We have also considered the case with the polyanthrylene polymer neighbored with PTCDA-Au polymer, the noncovalent interaction result in a torsional angle decrease of 5° (see supporting information Figure S5). Although we did not calculate it, we believe the adsorption of the BA monomer and PTCDA-Au polymer together on Au surface will further decrease the torsional angle. In summary, on-surface synthesis of 7-AGNRs can be tuned by noncovalent interactions. Intramolecular cyclodehydrogenation of DBBA molecules is promoted by noncovalent intermolecular interactions, resulting in organometallic bisanthene-Au polymers instead of polyanthrylenes. With the assistance of noncovalent interactions, the temperature for cyclodehydrogenation of neighboring anthryl groups can be significantly decreased and thus on-surface synthesis of GNRs can be realized at lower temperatures. Our STM study revealed a domino-like reaction process of the GNRs synthesis, in which the cyclodehydrogenation is initiated at the terminals of the polyanthracenes and then propagates along one side of the polymer chains. Our work demonstrates that bicomponent intermolecular interactions are effective parameters to tune the reaction pathway in on-surface synthesis. 10 / 17


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Methods Experimental Details. STM measurements were performed using an Omicron low-temperature STM operating at 78 K in ultrahigh vacuum (base pressure of 1× 10 mbar). Single crystalline Au(111) surfaces were cleaned by repeated Ar+ sputtering and annealing (720 K). DBBA and Br4-PTCDA molecules were evaporated from quartz crucibles onto the Au(111) substrate. During deposition the temperatures of the crucibles were kept at 458 K and 528 K, respectively. A direct current tungsten filament located on the back side of the sample holder was used to heat the samples and the sample temperatures were measured with thermocouple. An electrochemically etched tungsten tip was used for topographic measurements. The STM images were recorded in the constant-current mode. Theoretical calculation. Dispersion-corrected density functional theory (DFT-D3) calculations were conducted with the Vienna ab-initio Simulation Package (VASP) code.39-41

The

Projector

Augmented

Wave

(PAW)

method

using

the

Perdew-Burke-Ernzerhof (PBE) exchange-correlation function was applied for geometry optimizations.42,43 The plane-wave energy cutoff used for all calculations was 400 eV. The convergence criterion for the forces of structure relaxations is 0.01 eV Å . A supercell arrangement was used with a 15 Å vacuum layer to avoid spurious interactions between the nanoribbons and periodic images. The k-point grid of 6×1×1 generated by the Monkhorst-Pack scheme was adopted for geometry optimizations.44 AUTHOR INFORMATION Corresponding Author *E-mail: [email protected] Notes The authors declare no competing financial interest.

ACKNOWLEDGMENTS This work was financially supported by NSFC (No.11574403 and No.11374374) and the computation part of the work was supported by National Super-Computer Center in Guangzhou. 11 / 17



References 1. Son, Y. W.; Cohen, M. L.; Louie, S. G. Energy Gaps in Graphene Nanoribbons.

Phys. Rev. Lett. 2006, 97, 216803. 2. Han, M. Y.; Ozyilmaz, B.; Zhang, Y. B.; Kim, P. Energy Band-Gap Engineering of Graphene Nanoribbons. Phys. Rev. Lett. 2007, 98, 206805. 3. Li, X.; Wang, X.; Zhang, L.; Lee, S.; Dai, H. Chemically Derived Ultrasmooth Graphene Nanoribbon Semiconductors. Science 2008, 319, 1229−1232. 4. Jiao, L.; Zhang, L.; Wang, X.; Diankov, G.; Dai, H. Narrow Graphene Nanoribbons from Carbon Nanotubes. Nature 2009, 458, 877. 5. Xie, L.; Jiao, L.; Dai, H. Selective Etching of Graphene Edges by Hydrogen Plasma. J. Am. Chem. Soc. 2010, 132, 14751. 6. Cai, J.; Ruffieux, P.; Jaafar, R.; Bieri, M.; Braun, T.; Blankenburg, S.; Muoth, M.; Seitsonen, A. P.; Saleh, M.; Feng, X.; Müllen, K.; Fasel, R. Atomically Precise Bottom-Up Fabrication of Graphene Nanoribbons. Nature 2010, 466, 470−473. 7. Linden, S.; Zhong, D.; Timmer, A.; Aghdassi, N.; Franke, J. H.; Zhang, H.; Feng, X.; Müllen, K.; Fuchs, H.; Chi, L.; et al. Electronic structure of spatially aligned graphene nanoribbons on Au (788). Phys. Rev. Lett. 2012, 108, 216801. 8. Ruffieux, P.; Wang, S.; Yang, B.; Sánchez-Sánchez, C.; Liu, J.; Dienel, T.; Talirz, L.; Shinde, P.; Pignedoli, C. A.; Passerone, D.; Dumslaff, T.; Feng, X.; Müllen, K.; Fasel, R. On-Surface Synthesis of Graphene Nanoribbons with Zigzag Edge Topology. Nature 2016, 531, 489−492. 9. Talirz, L.; Ruffieux, P.; Fasel, R. On-Surface Synthesis of Atomically Precise Graphene Nanoribbons. Adv. Mater. 2016, 28, 6222−6231. 10. Chen, Y.-C.; de Oteyza, D. G.; Pedramrazi, Z.; Chen, C.; Fischer, F. R.; Crommie, M. F. Tuning the Band Gap of Graphene Nanoribbons Synthesized from Molecular Precursors. ACS Nano 2013, 7, 6123−6128. 11. Talirz, L.; Söde, H.; Dumslaff, T.; Wang, S.; Sanchez-Valencia, J. R.; Liu, J.; Shinde, P.; Pignedoli, C. A.; Liang, L.; Meunier, V.; Plumb, N. C.; Shi, M.; Feng, X.; Narita, A.; Müllen, K.; Fasel, R.; Ruffieux, P. On-Surface Synthesis and Characterization of 9-Atom Wide Armchair Graphene Nanoribbons. ACS Nano 12 / 17


Page 12 of 22

Page 13 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


2017, 11, 1380−1388. 12. Zhang, H.; Lin, H.; Sun, K.; Chen, L.; Zagranyarski, Y.; Aghdassi, N.; Duhm, S.; Li, Q.; Zhong, D.; Li, Y.; et al. On-Surface Synthesis of Rylene-Type Graphene Nanoribbons. J. Am. Chem. Soc. 2015, 137, 4022−4025. 13. Liu, J.; Li, B.-W.; Tan, Y.-Z.; Giannakopoulos, A.; SanchezSanchez, C.; Beljonne, D.; Ruffieux, P.; Fasel, R.; Feng, X.; Müllen, K. Toward Cove-Edged Low Band Gap Graphene Nanoribbons. J. Am. Chem. Soc. 2015, 137, 6097−6103. 14. Bronner, C.; Stremlau, S.; Gille, M.; Brauße, F.; Haase, A.; Hecht, S.; Tegeder, P. Aligning the Band Gap of Graphene Nanoribbons by Monomer Doping. Angew.

Chem. Int. Ed. 2013, 52, 4422−4425. 15. Nguyen, G. D.; Toma, F. M.; Cao, T.; Pedramrazi, Z.; Chen, C.; Rizzo, D. J.; Joshi, T.; Bronner, C.; Chen, Y.-C.; Favaro, M.; Louie, S. G.; Fischer, F. R.; Crommie, M. F. Bottom-Up Synthesis of N = 13 Sulfur-Doped Graphene Nanoribbons. J. Phys.

Chem. C 2016, 120, 2684−2687. 16. Kawai, S.; Saito, S.; Osumi, S.; Yamaguchi, S.; Foster, A. S.; Spijker, P.; Meyer, E. Atomically Controlled Substitutional BoronDoping of Graphene Nanoribbons.

Nat. Commun. 2015, 6, 8098. 17. Durr, R. A.; Haberer, D.; Lee, Y. L.; Blackwell, R.; Kalayjian, A. M.; Marangoni, T.; Ihm, Jisoon; Louie, S. G.; Fischer, F. R. Orbitally Matched Edge-Doping in Graphene Nanoribbons. J. Am. Chem. Soc. 2018 140, 807-813. 18. Hayashi, H.; Yamaguchi, J.; Jippo, H.; Hayashi, R.; Aratani, N.; Ohfuchi, M.; Sato, S.; Yamada, H. Experimental and Theoretical Investigations of Surface-Assisted Graphene Nanoribbon Synthesis Featuring Carbon–Fluorine Bond Cleavage.ACS

nano 2017, 11, 6204-6210. 19. Cai, J.; Pignedoli, C. A.; Talirz, L.; Ruffieux, P.; Söde, H.; Liang, L.; Meunier, V.; Berger, R.; Li, R.; Feng, X.; Müllen, K.; Fasel, R. Graphene Nanoribbon Heterojunctions. Nat. Nanotechnol. 2014, 9, 896−900. 20. Chen, Y.-C.; Cao, T.; Chen, C.; Pedramrazi, Z.; Haberer, D.; de Oteyza, D. G.; Fischer, F. R.; Louie, S. G.; Crommie, M. F. Molecular Bandgap Engineering of Bottom-up Synthesized Graphene Nanoribbon Heterojunctions. Nat. Nanotechnol. 13 / 17



2015, 10, 156−160. 21. Nguyen, G. D.; Tsai, H. Z.; Omrani, A. A.; Marangoni, T.; Wu, M.; Rizzo, D. J.; Rodgers, G. F.; Cloke, R. R.; Durr, R. A.; Sakai, Y.; Liou, F.; Aikawa, A.S.; Chelikowsky, J. R.; Louie, S. G.; Fisher, F. R.; Crommie, M. F. Atomically Precise Graphene Nanoribbon Heterojunctions from A Single Molecular Precursor Nat.

Nanotechnol., 2017, 12, 1077-1082. 22. Liu, M.; Liu, M.; She, L.; Zha, Z.; Pan, J.; Li, S.; Li, T.; He, Y.; Cai, Z.; Wang, J.; Zheng, Y.; Qiu, X.; Zhong, D. Graphene-Like Nanoribbons Periodically Embedded with Four-and Eight-Membered Rings. Nat. Commun. 2017, 8, 14924. 23. Liu, M.; Liu, M.; Zha, Z.; Pan, J.; Qiu, X.; Li, T.; Wang, J.; Zheng, Y.; Zhong, D. Thermally Induced Transformation of Nonhexagonal Carbon Rings in Graphene-like Nanoribbons. J. Phys. Chem. C 2018, 112, 9586−9592. 24. Llinas, J. P.; Fairbrother, A.; Barin, G.; Ruffieux, P.; Shi, W.; Lee, K.; Choi, B. Y.; Braganza, R.; Kau, N.; Choi, W.; Chen, C.; Pedramrazi, Z.; Dumslaff, T.; Narita, A.; Feng, X.; Müllen, K.; Fischer, F.; Zettl, A.; Crommie, M.; Fasel, R.; Bokor, J. Short-Channel Field Effect Transistors with 9-Atom and 13-Atom Wide Graphene Nanoribbons. Nat. Commun. 2017, 8, 633. 25. Chen, Z.; Zhang, W.; Wang, X.-Y.; Palma, C.-A.; Lodi Rizzini, A.; Liu, B.; Abbas, A.; Richter, N.; Martini, L.; Berger, R.; Klappenberger, F.; Mishra, N.; Coletti, C.; Kläui, M.; Candini, A.; Affronte, M.; Zhou, C.; De Renzi, V.; del Pennino, U.; Barth, J. V.; Räder, H. J.; Narita, A.; Feng, X.; Müllen, K.; Cavani, N.; Lu, H. Synthesis of Graphene Nanoribbons by Ambient-pressure Chemical Vapor Deposition and Device Integration. J. Am. Chem. Soc. 2016, 138, 15488−15496. 26. Kolmer, M.; Zebari, A. A. A.; Prauzner-Bechcicki, J. S.; Piskorz, W.; Zasada, F.; Godlewski, S.; Such, B.; Sojka, Z.; Szymonski, M. Polymerization of Polyanthrylene on a Titanium Dioxide (011)-(2 × 1) Surface. Angew. Chem., Int.

Ed. 2013, 52, 10300−10303. 27. Ma, C.; Xiao, Z.; Zhang, H.; Liang, L.; Huang, J.; Lu, W.; Sumpter, B. G.; Hong, K.; Bernholc, J.; Li, A.P. Controllable Conversion of Quasi-freestanding Polymer Chains to Graphene Nanoribbons. Nat. Commun., 2017, 8, 14815. 14 / 17


Page 14 of 22

Page 15 of 22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


28. Han, P.; Akagi, K.; Canova, F. F.; Mutoh, H.; Shiraki, S.; Iwaya, K.; Weiss, P. S.; Asao, N.; Hitosugi, T. Bottom-Up GrapheneNanoribbon Fabrication Reveals Chiral Edges and Enantioselectivity. ACS Nano 2014, 8, 9181−9187. 29. Sánchez-Sánchez, C.; Dienel, T.; Deniz, O.; Ruffieux, P.; Berger, R.; Feng, X.; Müllen, K.; Fasel, R. Purely Armchair or Partially Chiral: Noncontact Atomic Force Microscopy Characterization of DibromoBianthryl-Based Graphene Nanoribbons Grown on Cu(111). ACS Nano 2016, 10, 8006−8011. 30. Simonov, K. A.; Vinogradov, N. A.; Vinogradov, A. S.; Generalov, A. V.; Zagrebina, E. M.; Svirskiy, G. I.; Cafolla, A. A.; Carpy, T.; Cunniffe, J. P.; Taketsugu, T.; Lyalin, A.; Mårtensson, N.; Preobrajenski, A. B. From Graphene Nanoribbons on Cu(111) to Nanographene on Cu(110): Critical Role of Substrate Structure in the Bottom-Up Fabrication Strategy. ACS Nano 2015, 9, 8997−9011. 31. Shang, J.; Wang, Y.; Chen, M.; Dai, J.; Zhou, X.; Kuttner, J.; Hilt, G.; Shao, X.; Gottfried, J. M.; Wu, K. Assembling Molecular Sierpiński Triangle Fractals. Nat.

Chem. 2015, 7, 389−393. 32. Otero, R.; Schöck, M.; Molina, L. M.; Lægsgaard, E.; Stensgaard, I.; Hammer, B.; Besenbacher, F. Guanine Quartet Networks Stabilized by Cooperative Hydrogen Bonds. Angew. Chem., Int. Ed. 2005, 44, 2270–2275. 33. Zhang, H.; Franke, J. H.; Zhong, D.; Li, Y.; Timmer, A.; Arado, O. D.; Mönig, H.; Wang, H.; Chi, L.; Wang, Z.; et al. Surface Supported Gold–Organic Hybrids: On– Surface Synthesis and Surface Directed Orientation. Small, 2014, 10, 1361-1368. 34. Jacobse, P. H.; van den Hoogenband, A.; Moret, M.; Gebbink, R. J. M. K.; Swart, I. Aryl Radical Geometry Determines Nanographene Formation on Au(111).

Angew. Chem. Int. Ed., 2016, 55, 13052−13055. 35. Talirz, L.; Söde, H.; Cai, J.; Ruffieux, P.; Blankenburg, S.; Jafaar, R.; Berger, R.; Feng, X.; Müllen, K.; Passerone, D.; Fasel, R.; Pignedol, C. A. Termini of Bottom-Up Fabricated Graphene Nanoribbons. J. Am. Chem. Soc. 2013, 135, 2060–2063. 36. Wang, S.; Talirz, L.; Pignedoli, C. A.; Feng, X.; Müllen, K.; Fasel, R.; Ruffieux, P. Giant Edge State Splitting at Atomically Precise Graphene Zigzag Edges. Nat. 15 / 17



Commun. 2016, 7, 11507. 37. Blankenburg, S.; Cai, J.; Ruffieux, P.; Jaafar, R.; Passerone, D.; Feng, X.; Müllen, K.; Fasel, R.; Pignedoli, C. A. Intraribbon Heterojunction Formation in Ultranarrow Graphene Nanoribbons. ACS Nano 2012, 6, 2020–2025. 38. Ma, C.; Liang, L.; Xiao, Z.; Puretzky, A. A.; Hong, K.; Lu, W.; Meunier, V.; Bernholc, J.; Li, A. P. Seamless Staircase Electrical Contact to Semiconducting Graphene Nanoribbons. Nano letters 2017 17, 6241-6247. 39. Grimme, S. Semiempirical Gga-Type Density Functional Constructed with a Long-Range Dispersion Correction. J. Comput. Chem. 2006, 27, 1787−1799. 40. Kresse, G.; Hafner, J. Ab Initio Molecular Dynamics for Liquid Metals. Phys. Rev.

B 1993, 47, 558–561. 41. Kresse, G.; Hafner, J. Efficient Iterative Schemes for Ab Initio Total-Energy Calculations Using a Plane-Wave Basis Set. Phys. Rev. B 1996, 54, 11169–11186. 42. Blöchel, P. E. Projector Augmented-Wave Method. Phys. Rev. B 1994, 50, 17953–17979. 43. Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 1996, 77, 3865. 44. Monkhorst, H. J.; Pack, J. D. Special Points for Brillouin-Zone Integrations. Phys.

Rev. B 1976, 13, 5188−5192.

16 / 17


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Tuning On-Surface Synthesis of Graphene Nanoribbons by

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