Two-Dimensional Carbon Compounds Derived from Graphyne with Chemical Properties Superior to Those of Graphene

Transcription

1 Supplementary Information Two-Dimensional Carbon Compounds Derived from Graphyne with Chemical Properties Superior to Those of Graphene Jia-Jia Zheng, 1,2 Xiang Zhao, 1* Yuliang Zhao, 2 and Xingfa Gao 2,3* 1 Institute for Chemical Physics & Department of Chemistry, State Key Laboratory of Electrical Insulation and Power Equipment, Xi an Jiaotong University, Xi an , China 2 CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing , China 3 College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang , China * xzhao@mail.xjtu.edu.cn (X.Z.), gaox@ihep.ac.cn (X.G.) 1

2 Full citation of Gaussian 09 (reference 42) Frisch, M. J., Trucks, G. W., Schlegel, H. B., Scuseria, G. E., Robb, M. A., Cheeseman, J. R., Scalmani, G., Barone, V., Mennucci, B., Petersson, G. A., Nakatsuji, H., Caricato, M., Li, X., Hratchian, H. P., Izmaylov, A. F., Bloino, J., Zheng, G., Sonnenberg, J. L., Hada, M., Ehara, M., Toyota, K., Fukuda, R., Hasegawa, J., Ishida, M., Nakajima, T., Honda, Y., Kitao, O., Nakai, H., Vreven, T., Montgomery, J. A., Jr., Peralta, J. E., Ogliaro, F., Bearpark, M., Heyd, J. J., Brothers, E., Kudin, K. N., Staroverov, V. N., Keith, T., Kobayashi, R., Normand, J., Raghavachari, K., Rendell, A., Burant, J. C., Iyengar, S. S., Tomasi, J., Cossi, M., Rega, N., Millam, J. M., Klene, M., Knox, J. E., Cross, J. B., Bakken, V., Adamo, C., Jaramillo, J., Gomperts, R., Stratmann, R. E., Yazyev, O., Austin, A. J., Cammi, R., Pomelli, C., Ochterski, J. W., Martin, R. L., Morokuma, K., Zakrzewski, V. G., Voth, G. A., Salvador, P., Dannenberg, J. J., Dapprich, S., Daniels, A. D., Farkas, O., Foresman, J. B., Ortiz, J. V., Cioslowski, J., Fox, D. J. Gaussian 09, Revision C.01; Gaussian, Inc., Wallingford CT,

3 Effects of solvent, biradical character and basis set on dichlorocarbene additions Figure S1. Reaction-energy profiles for dichlorocarbene additions on graphyne calculated at various levels. Only pathways of generating p1 are presented for clarity (for others see Table S1). The solvent used in these calculations is dichlorobenzene. Table S1. Single-point energies (kcal mol 1 ) of species along the reaction pathways for dichlorocarbene addition calculated with various methods on the basis of B3LYP/6-31G(d) optimized geometries. species B3LYP/6-31G(d) B3LYP/6-31G(d) B3LYP/6-311+G(d, p) B3LYP/6-311+G(d, p) UB3LYP/6-31G(d) UB3LYP/6-31G(d) (gas) (DiChloroBenzene) (gas) (DiChloroBenzene) (gas) (DiChloroBenzene) r+ccl p p p p int ts ts ts ts ts

4 Geometric details for dichlorocarbene additions Figure S2. Optimized geometries along the reaction paths of dichlorocarbene additions calculated at B3LYP/6-31G(d) level. The distances labeled in the panels are given in Å. C, green; Cl, brown; H, light blue. 4

5 Dichlorocarbene additions with periodic model Figure S3. Regioselectivity of dichlorocarbene additions on β-graphyne based on a periodic model. Energies are calculated using a unit cell and are referenced to the most favorable one (in kcal mol 1 ). C, green; Cl, brown. 5

6 Regioselectivity of hydrogen additions Figure S4. (a) Schematic representation of α-graphyne with a quadrangle indicating the unit cell. (b)-(g) Atomic arrangements for various 1H 2 addition patterns. The black dots in (d) and (f) represent hydrogen atoms added on the opposite side. Energies are given in kcal mol 1 with respect to the most favorable one (the in-plane trans- configuration b). C, green; H, light blue. 6

7 Multi-hydrogen addition patterns Figure S5. Structures and relative energies (in kcal mol -1 ) for multi-hydrogenated graphynes with various hydrogen distribution types. C, green; H, light blue. 7

8 Mobility of Added Chemical Groups We studied the mobility of O atom in graphyne basal plane using a cluster model of α-graphyne. Two types of motion are possible: O-migration and O-turning (Figure S6a). O-migration represents a geometry rearrangement with an oxygen atom migrating to its nearest triple bond located in the same 18-membered ring, and O-turning corresponds to a process of moving an oxygen atom from its pristine 18-membered ring to the adjacent one without changing the atomic linkages. Figure S6a presents the model structure composing of two adjacent 18-membered rings derived from α- graphyne with an oxygen atom adding to their conjunct triple bonds and hydrogen atoms saturating the dangling sp 2 carbon atoms. The atomic rearrangement products are also illustrated. Shown in Figure S6b are the reaction-energy profiles for full structural transformation processes of O-migration and O-turning calculated at B3LYP/6-31G(d) level. The solvent effect was also evaluated via single-point energy calculations based on B3LYP/6-31G(d) optimized geometries. As shown in table 1, the solvent might be expected to have little influence on the reaction barriers and thermodynamics of the isomerizations of O-2DCC. For the isomerization of O-migration, we located four transition states and three intermediates along the reaction pathway (Figure S6b), demonstrating the stepwise character of this process. As Figure S6b shows, the oxygen atom initially migrate away from the plane of graphyne oxide accompanied with a C-O bond breaking to form the intermediate int1 (see FigrueS7 for detail structural parameters). This reaction is thermodynamically uphill (15.0 kcal mol 1 ) with an energy barrier of 15.6 kcal mol 1. In the next step, the migration of oxygen atom has to overcome a barrier of 24.2 kcal mol 1 to generate the intermediate int2 containing a four-membered ring, which is shown to be significantly unstable. After forming int2, the oxygen atom will move towards the target triple bond in a quick manner via two transition states with much small energy barriers. A similar stepwise mechanism was verified for the isomerization of O-turning consisting of three transition states and two intermediates. The first step of this process is the same as that of O-migration with a C-O bond breaking and oxygen atom deviating from the oxide sheet. In the subsequent step, the oxygen rotates around the carbon chain to move towards the other 18-membered ring with the formation of int1, which is actually identical with int1 in our simple cluster model. And finally, after the reformulation of C-O bond, the full process of O-turning is accomplished. The energy barriers for the rate-determining steps of migration and turning of oxygen are calculated to be 24.2 kcal mol 1 and 15.6 kcal mol 1, respectively. These barriers indicate a feasible mobility of the added chemical groups at relatively high temperatures, which is favorable to obtain structurally orderly 2DCCs. 8

9 Figure S6. (a) Schematic representations of structure reconstructions of O-2DCC with a cluster model and (b) Reaction-energy profiles for O-migration and O-turning calculated in gas phase at B3LYP/6-31G(d) level. The Roman numerals label oxygen-addition sites. C, green; H, light blue. Table S2. Single-point energies (kcal mol 1 ) of species along the reaction pathways of O-2DCC isomerization calculated with various methods on the basis of B3LYP/6-31G(d) optimized geometries. species B3LYP/6-31G(d) (gas) B3LYP/6-31G(d) (Toluene) B3LYP/6-311+G(d, p) (gas) B3LYP/6-311+G(d, p) ( Toluene) r p p int1(1 ) int int ts1(1 ) ts ts ts ts

10 Figure S7. Optimized geometries along the reaction paths for structure reconstructions of O-2DCC. The distances labeled in the panels are given in Å. C, green; H, light blue. 10

11 Substituent Effect Figure S8. Electronic band structures and density of states (DOS) (top), 2 2 supercells (middle), diagrams illustrating the symmetry breaking mode (bottom) for (a) CH 2-2DCC and OH 1/3 -CH 2-2DCC. C, green; O, red; H, light blue. The band gap opening (~0.3eV) in OH 1/3 -CH 2-2DCC shows the feasibility of turning electronic properties of 2DCC through substitution reactions. 11