Supplementary Materials for

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1 advances.sciencemag.org/cgi/content/full/3/11/e /dc1 Supplementary Materials for Competitive chiral induction in a 2D molecular assembly: Intrinsic chirality versus coadsorber-induced chirality This PDF file includes: Ting Chen, Shu-Ying Li, Dong Wang, Li-Jun Wan Published 3 November 2017, Sci. Adv. 3, e (2017) DOI: /sciadv fig. S1. Relationship between the BIC-C7/1-octanol assembly and the substrate lattice. fig. S2. Calculated molecular models of the BIC-C7/1-octanol assembly. fig. S3. Formation of the CW network in the BIC-C7/(R)-6O assembly. fig. S4. Coassembly of (S)-BIC-C7 and 1-octanol. fig. S5. Chiral competitive coassembly of (S)-BIC-C7 and (R)-6O. fig. S6. Typical STM image of the assembly when (R)-BIC-C7, 1-octanol, and (S)-6O are codeposited together. fig. S7. Chiral competition between chiral coabsorber and (R,R)-BIC-C7 [or (S,S)- BIC-C7]. fig. S8. Coassembly of (R)-BIC-C7 and 1-octanol before and after the presence of (S)-4O. fig. S9. Adaptable adsorption conformation of a trimeric unit in the BIC-C7/1- octanol coassembly. fig. S10. Calculated hexagonal units of the networks in the BIC-C7/(S)-6O coassembly. fig. S11. Calculated hexagonal units of the networks in the (R)-BIC-C7/1-octanol coassembly. fig. S12. Calculated hexagonal units of the networks in the (R)-BIC-C7/(S)-6O coassembly.

2 SUPPLEMENTARY MATERIALS fig. S1. Relationship between the BIC-C7/1-octanol assembly and the substrate lattice. (A) STM image of the BIC-C7/1-octanol assembly. I = na, V bias = V. (B) Atomic image of the HOPG surface. I = na, V bias = 0.05 V. fig. S2. Calculated molecular models of the BIC-C7/1-octanol assembly. (A) Molecular model of the CW trimeric unit. (B) Molecular model of the CCW trimeric unit. The dash lines represent hydrogen bonds.

3 fig. S3. Formation of the CW network in the BIC-C7/(R)-6O assembly. The thick blue sticks and thin blue sticks represent the backbones and the side chains of BIC-C7 molecules, respectively. The green sticks denote the (R)-6O molecules. fig. S4. Coassembly of (S)-BIC-C7 and 1-octanol. (A and B) Typical STM images of the (S)-BIC-C7/1-octanol assembly. I = na, V bias = V. An illustration of the CW network is superposed in figure B, in which the thick blue sticks, the thin blue sticks, the red sticks, and the yellow sticks represent the backbones of (S)-BIC-C7, the achiral side chain of (S)-BIC-C7, the side chain with a (S)-type chiral center of (S)-BIC-C7, and the co-adsorbed 1-octanol molecules, respectively. (C) Atomic STM image of the HOPG surface. I = na, V bias = 0.05 V. (D) Calculated molecular model of the trimer unit in the (S)-BIC-C7/1-octanol assembly. The red dot marks the (S)-type chiral center chiral center. (E) Illustration of the formation of CW network in (S)-BIC-C7/1-octanol assembly.

4 fig. S5. Chiral competitive coassembly of (S)-BIC-C7 and (R)-6O. (A) Typical STM image of the network formed by (S)-BIC-C7 and (R)-6O. I = na, V bias = V. (B) Illustration of the formation of the (S)-BIC-C7/(R)-6O co-assembly. The thick blue sticks and the thin blue sticks represent the backbone and the achiral side chain of (S)-BIC-C7 respectively. The red sticks and the green sticks denote the side chain with a (S)-type chiral center in (S)-BIC-C7 and the co-adsorbed (R)-6O, respectively. fig. S6. Typical STM image of the assembly when (R)-BIC-C7, 1-octanol, and (S)-6O are codeposited together. The fraction of (S)-6O in the solution is 30% in volume. I = na, V bias = V.

5 fig. S7. Chiral competition between chiral coabsorber and (R,R)-BIC-C7 [or (S,S)-BIC-C7]. (A and B) Typical STM images of the (R,R)-BIC-C7/(S)-6O assembly. (C and D) Typical STM images of the (S,S)-BIC-C7/(R)-6O assembly. I = na, V bias = V. The blue stick represents the backbone of BIC derivative. fig. S8. Coassembly of (R)-BIC-C7 and 1-octanol before and after the presence of (S)-4O.

6 fig. S9. Adaptable adsorption conformation of a trimeric unit in the BIC-C7/1-octanol coassembly. The starting structural models used for theoretical simulations were built based on STM images, in which the backbone of BIC derivatives can be clearly distinguished. And thus, the orientation of the backbones of BIC derivative within a trimeric unit in the co-assembly can be fixed, and the only flexible part is the side chain which can rotate along the C-O bond. Therefore, for a trimeric unit in the co-assembly of BIC derivative and 1-octanol analogue, there are four adsorption conformations adoptable when confined on surface, named conformation Ⅰ, conformation Ⅱ, conformation Ⅲ, and conformation Ⅳ. As indicated in the figure, conformation Ⅰ and conformation Ⅱ are enantiomers, and conformation Ⅲ and conformation Ⅳ are enantiomers too. If the side chains in conformation Ⅰ and conformation Ⅲ are flipped 180 along the C-O bond, conformation Ⅱ and conformation Ⅳ can be obtained, respectively.

7 fig. S10. Calculated hexagonal units of the networks in the BIC-C7/(S)-6O coassembly. NetworkⅠ, Ⅱ, Ⅲ, and Ⅳ in the BIC-C7/(S)-6O co-assembly correspond to trimeric units with conformation Ⅰ, Ⅱ, Ⅲ, and Ⅳ, respectively. Energy shown below the molecular model is its total energy. With comparison of the energy of the four networks it can be seen that network Ⅱ is energetically favored. And its chirality agrees with the chirality we observed in STM images of BIC-C7/(S)-6O co-assembly. Moreover, the difference in energy of the energetically favored CW network and the energetically favored CCW network is kcal/mol. Thus, energy difference for a trimeric unit (the basic chiral unit of the 2D molecular assembly) is 4.89 kcal/mol (about 8 k BT), suggesting obvious bias to CW network can be achieved. The simulation result is consistent with the experiment results.

8 fig. S11. Calculated hexagonal units of the networks in the (R)-BIC-C7/1-octanol coassembly. Energy shown below the molecular model is its total energy. It can be seen that the energy of the energetically favored CCW network (NetworkⅠ) is about 10 kcal/mol higher than that of the energetically favored CW network (Network Ⅳ), implying an efficient induction of CCW chirality in the (R)-BIC-C7/1-octanol. The simulation results are consistent with the experimental results.

9 fig. S12. Calculated hexagonal units of the networks in the (R)-BIC-C7/(S)-6O coassembly. As revealed, Network Ⅳ with CW chirality is energetically favored, just as observed in STM measurement. Note that the adsorption conformation of side chain in Network Ⅳ is unfavored in (R)-BIC-C7/1-octanol assembly. It is suggested to be a compromised result that an unfavored adsorption conformation is adopted to minimize the steric hindrance induced by the chiral center.