IMMEDIATE ONLINE ACCEPTED (IOA) ARTICLE This article presented here has been peer reviewed and accepted for publication in CCS Chemistry. The present version of this manuscript has been posted at the request of the author prior to copyediting and composition and will be replaced by the final published version once it is completed. The DOI will remain unchanged. IOA Posting Date: July 16, 2020 TITLE: Constituent Isomerism Induced Quasicrystal and Frank-Kasper Superlattices Based on Nano-sized Shape Amphiphiles AUTHORS: Zebin Su, Jiahao Huang, Wenpeng Shan, Xiao-Yun Yan, Ruimeng Zhang, Tong Liu, Yuchu Liu, Qing-Yun Guo, Fenggang Bian, Xiaran Miao, Mingjun Huang, Stephen Z.D. Cheng DOI: 10.31635/ccschem.020.202000338 Page 1 of 16 CCS Chemistry 1 2 3 Constituent Isomerism Induced Quasicrystal and Frank-Kasper σ Superlattices 4 5 Based on Nano-sized Shape Amphiphiles 6 7 Authors: Zebin Su,1,2† Jiahao Huang,2† Wenpeng Shan,2 Xiao-Yun Yan,2 Ruimeng Zhang,2 8 9 Tong Liu,2 Yuchu Liu,2 Qing-Yun Guo,2 Fenggang Bian,3 Xiaran Miao,3 Mingjun Huang,1* 10 Stephen Z.D. Cheng1,2* 11 12 13 Affiliations: 14 1 15 South China Advanced Institute for Soft Matter Science and Technology, School of Molecular 16 Science and Engineering, South China University of Technology, Guangzhou, 510640. 17 2Department of Polymer Science, College of Polymer Science and Polymer Engineering, 18 19 University of Akron, Akron, OH, 44325. 20 3Shanghai Synchrotron Radiation Facility, Zhangjiang Laboratory, Shanghai Advanced 21 Research Institute, Chinese Academy of Sciences, Shanghai, 201204. 22 23 Corresponding Author: [email protected]; [email protected]; 24 25 Z. Su and J. Huang contributed equally to this work 26 27 28 Abstract 29 30 Naturally, subtle variations in the chemical structure of constituent molecules may significantly 31 affect their multiscale spatial arrangements, properties and functions. Deceptively simple 32 33 spherical assemblies supply an ideal platform to investigate how subtle chemical differences 34 affect hierarchical assembled structures. Here, we report two sets of nano-sized shape 35 amphiphiles, which are constructed by a triphenylene core and six polyhedral oligomeric 36 silsesquioxane cages at periphery grafted onto it through linkers. The slight differences of these 37 38 samples are merely several methylene units in their linkers, including several pairs of 39 constituent isomers. These nano-sized shape amphiphiles self-assemble into a variety of 40 unconventional spherical packing structures, which include the F-K σ phase and dodecagonal 41 quasicrystal. Several types of unconventional phase transitions were systematically 42 investigated. We alternate the conventional columnar phases of discotic molecules to 43 44 unconventional spherical packing phases. These unconventional structures may shed a light 45 into discovering discotic mesogens based materials with new properties and functions. 46 47 48 49 Keywords: Self-assembly, Frank-Kasper Phase, Quasicrystal, Shape-amphiphile, Constituent 50 Isomer. 51 52 53 54 Introduction 55 56 It is well recognized that not only the chemical structure of soft matter determines many 57 associated physical properties, but also the spatial arrangements of constituent molecules in 58 multiple length scales. Subtle variations in chemical structures of constituent molecules may 59 induce considerable transformation on their spatial arrangements and further affect their 60 This article presented here has been accepted for publication in CCS Chemistry and is posted at the request of the author prior to copyediting and composition. © 2020 Chinese Chemical Society. CCS Chemistry Page 2 of 16 1 2 3 functions and properties.1-3 One of the well-known examples is the sickle cell anemia, just a 4 5 single amino residue mutation where the glutamic acid is substituted by the valine, leads to the 4 6 sickle-like shape red blood cell and results in an abnormality in oxygen-carrying function. 7 Moreover, even for the isomer case, a single leucine to isoleucine substitution in the envelope 8 code 348 of friend murine leukemia virus could dramatically alter the hemolytic effect.5 Tiny 9 10 mutation in the primary structure of a protein may affect its secondary, tertiary and tertiary 11 structure. Furthermore, it could dramatically change the function of those protein. Similar to 12 biomacromolecules, in the case of the soft matter self-assembly, a small difference in the 13 molecular chemical structure may result in a distinct self-assembled structure. For example, 14 one methylene difference in the repeat unit of polymer can turn the right-handed helix lamellar 15 6 16 crystal into left-handed helix lamellar crystal. Specifically, Percec and coworker reported 17 constituent isomers of 3,4- and 3,5- disubstituted phenyl ether dendrons self-assemble into a 18 series of dissimilar phase structures.7-9 19 20 Particularly, spherical assemblies are highly sensitive to a balance of enthalpic and entropic 21 interactions induced by subtle change of chemical structure. Besides the ubiquitous densely 22 23 packed structures, such as body-centered cubic phase (BCC), hexagonal close packed phase 24 (HCP), and face-centered cubic phase (FCC), there is a class of complex spherical packing 25 phases named Frank-Kasper (F-K) phases, which are originally discovered in metal alloys.10- 26 11 F-K phases are exclusively constructed with tetrahedrally arranged spherical motifs, 27 10-11 28 resulting in so-called tetrahedrally close packing. Often, dodecagonal quasicrystal (DDQC) 29 phase with 12-fold orientational symmetry and only one-dimensional translational symmetry 30 are closely associated with FK phases, due to the similarity in local tetrahedral packing rules.12- 31 14 Complex F-K phases and DDQC phase have not only observed in broad soft matter systems, 32 15-23 13, 24-31 32 33 including diblock copolymers, dendrimers, polymer colloids, small molecular 33-35 36-40 41-42 34 surfactants, giant molecules, and very recently, sugar-polyolefin conjugates, but 35 also mesoporous silica,43-44 binary nanocrystal superlattice,45-46 and DNA functionalized 36 nanoparticles.47-48 Several types of F-K phases only have considerably small differences 37 between their overall free energies. Therefore, self-assembled F-K phases are ideal platform 38 39 for investigating how subtle chemical differences affect hierarchical assembled structures. 40 41 Recently, we observed F-K Z phase (space group P6/mmm), F-K A15 phase (space group Pm3 38 42 푛), and BCC phase (space group Im3 m) in a set of nano-sized shape amphiphiles. Shape 43 amphiphiles refers to molecules with defined shape and competing interactions.49-51 These 44 dissimilar structures were induced by varying the number of a few methylene units in the 45 linkers between a core and periphery groups. In this article, we design and systematically 46 investigate two new sets of nano-sized shape amphiphiles, in which a triphenylene core is 47 48 attached with six identical polyhedral oligomeric silsesquioxane (POSS) cages at the periphery 49 through covalent linkers containing amide groups (Figure 1). The only slightly difference of 50 these samples are their linkers. For the first set of samples, Tp-Ph-Cn-6BP (n=3-11), in which 51 the phenyl group of the linker is conjugated with the triazole group, contains n (n=3-11) 52 methylene units between the amide group and BPOSS cage. The second set of samples, Tp- 53 Bn-Cm-6BP (m=2-5), in which the benzyl group of the linker connects with the triazole group, 54 contains m (m=2-5) methylene units between the amide group and BPOSS cage. Moreover, 55 56 Tp-Bn-Cm-6BP (m=2-5) and Tp-Ph-Cn-6BP (n=3-6) construct four pairs of constituent 57 isomers. 58 59 60 This article presented here has been accepted for publication in CCS Chemistry and is posted at the request of the author prior to copyediting and composition. © 2020 Chinese Chemical Society. Page 3 of 16 CCS Chemistry 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 Figure 1. Molecular cartoon model and chemical structures of the nano-sized shape 29 amphiphiles. (a) Schematic representation of a nanosized shape amphiphile, in which the light- 30 31 yellow disc and blue cube present the triphenylene core and BPOSS cages, respectively. The 32 chemical structures of the different linkers are presented in blue dashed box and illustrated by 33 grey wavy segments. The red chips on the grey wavy segment present the amide groups. (b) 34 The chemical structure of molecule Tp-Ph-C3-6BP. Hydrogen atoms of this molecule are not 35 shown for clarity. 36 37 The relatively weak π-π interaction supplied by triphenylene cores, together with the hydrogen 38 39 bonding interaction supplied by amide groups in the linkers provide the enthalpic driving force 40 for the self-assembly of these nano-sized shape amphiphiles. The relatively bulky BPOSS 41 cages at the periphery significantly increase the steric hindrance as an entropic reason to limit 42 these molecules to form columnar structure as which are often observed in discotic liquid 43 44 crystals. Therefore, tuning the link length and type may manipulate the finely balance between 45 the enthalpic and entropic contributions towards free energies of the phases. Through 46 systematically investigating the self-assembly behaviors of these giant shape amphiphiles, we 47 report the observation of various of phases, including DDQC phase, F-K σ phase (space group 48 49 푃42/푚푛푚), BCC phase and hexagonal columnar (HEX) phase (planar symmetry group p6mm). 50 Triphenylenes usually utilized as mesogenic units in discotic liquid crystals and side group 51 liquid crystalline polymers for applications in semiconductors.52-53 The discovery of a series of 52 spherical packing phases in these triphenylene-based nano-sized shape amphiphiles enrich the 53 54 self-assembled hierarchical structures of triphenylenes, which may facilitate the development 55 of triphenylene based materials for new properties and applications.