Self-Assembly Behavior Shifting to Crystal Formation of Chiral

Article Cite This: Cryst. Growth Des. XXXX, XXX, XXX−XXX

pubs.acs.org/crystal

Self-Assembly Behavior Shifting to Crystal Formation of Chiral Macrocyclic Tetraimines Masahide Tominaga,*,† Masatoshi Kawahata,†,§ Tsutomu Itoh,‡ and Kentaro Yamaguchi*,† †

Faculty of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan ‡ Center for Analytical Instrumentation, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan

Downloaded via UNIV OF EDINBURGH on January 29, 2019 at 00:59:25 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.

S Supporting Information *

ABSTRACT: The enantiopure macrocyclic tetraimines containing adamantane moieties (1, 2) were synthesized from (R,R)- or (S,S)-1,2-cyclohexanediamine and a disubstituted adamantane derivative having salicylaldehyde in moderate yield. Single crystals (1a) were obtained from a methanol/ chloroform mixture and 1. X-ray crystallographic analysis revealed that the macrocycles had a rhomboidal structure and were arranged into a molecular network bearing layer structures through CH···O and CH···π interactions. Racemic crystals (1·2-a) were formed from crystallization of 1 and 2 in a 1:1 stoichiometry. The macrocycles had a rhomboidal framework with a longer axis, and 1 and 2 were alternatively aligned into the molecular network composed of columnar structures by CH···π and CH···O interactions. Macrocycle 1 selfassembled into spheres, and their fused fibrous and network aggregates, and eventually were translated into crystals. Meanwhile, the mixing of both enantiomers 1 and 2 at a ratio of 1:1 afforded racemic crystals by way of similar self-assembled structures under identical conditions; however, the rate of crystal formation was faster than that of 1.

■

aqueous or organic media.29,30 The reports for the crystal formation through self-assembled nanostructures by using chiral organic compounds have been quite limited in contrast to the crystallization of amino acids and pharmaceutical agents.31,32 In this paper, we indicate the unique self-assembly behavior of enantiomeric macrocyclic tetraimines possessing adamantane moieties (1, 2) up to the formation of crystals. After addition of methanol to a chloroform solution of 1, the crystals (1a) were formed by way of spheres and their fused network aggregates. X-ray crystallographic analysis proved that the macrocycles had a rhomboidal structure, which were arranged into brick network structures. When the crystallization of both enantiomers of 1 and 2 were performed, the racemic crystals (1·2-a) were generated through similar supramolecular architectures, and the rate of crystallization was faster than that of the crystals built from 1 under identical conditions. In the crystal structure of 1·2-a, the macrocycles had a rhomboidal framework with the longer axis and were fabricated to supply a molecular network consisting of columnar structures.

INTRODUCTION The prediction, control, understanding, and elucidation of crystallization in natural and industrial processes are significant subjects for the development of functional and advanced crystalline solids with outstanding performance in various fields.1−10 The crystallization environments and conditions, including concentration, solvent, temperature, and pH in the solutions, influence the macroscopic properties of the crystalline solids, in terms of size, size distribution, and morphology.11−13 Additionally, the structures affect the packing of the component units by diverse and multiple noncovalent interactions, such as hydrogen bonds, π-stacking, and electrostatic interactions.14−16 A wide variety of crystallization routes have been investigated and reported for inorganic materials, metal−organic frameworks, small organic molecules, and proteins.17−26 Recently, unique crystallization phenomena, by way of well-defined supramolecular nanostructures built from amino acids and peptide derivatives, were reported in the area of sol−gel chemistry.27,28 These molecules, which possess amphiphilic characters, are fabricated to yield organogels composed of entangled nanofibers with the assistance of π-stackings, hydrogen bonds, and van der Waals interactions, which shift into molecular crystals under specific conditions. Recently, we have proven that macrocyclic compounds having adamantane moieties afford crystals through self-assembled nanostructures, which include hollow and solid spheres, and their fused network aggregates in © XXXX American Chemical Society

Received: October 27, 2018 Revised: January 3, 2019

A

DOI: 10.1021/acs.cgd.8b01617 Cryst. Growth Des. XXXX, XXX, XXX−XXX

Crystal Growth & Design

■

Article

RESULTS AND DISCUSSION Recently, we synthesized a macrocyclic tetraimine from ethylenediamine and a disubstituted adamantane derivative possessing salicylaldehyde, which provided crystals through self-assembled nanostructures, such as hollow spherical and network aggregates, in polar organic solutions. The aliphatic and bulky adamantane moieties in these molecules have advantages for the fabrication of these nanostructures and subsequent transformation into crystals. Thereby, we planned to design enantiopure macrocycles by using (R,R)- or (S,S)1,2-cyclohexanediamine to replace the ethylenediamine. Macrocyclic imines and their derivatives33−36 have been constructed from various organic compounds having aldehydes and amines for the development of porous crystalline solids toward gas adsorption and the inclusion of small organic molecules, owing to the easy and efficient synthesis and tunability and modification of their internal spcaces.37 Enantiomeric macrocycles containing adamantane parts (1, 2) were synthesized according to Scheme 1. The synthesis of 3 Figure 1. Molecular structures of 1 in crystal 1a from the top and side views. Solvent molecules are omitted for clarity.

Scheme 1. Synthesis of Macrocyclic Tetraimines with Adamantyl Groups

was 67.45°. The hydroxyl groups interacted with the nitrogen atoms of the imine parts through intramolecular hydrogen bonds (the distances of the oxygen and nitrogen atoms range from 2.60 to 2.65 Å). The macrocycles were arranged into brick network architectures bearing layer structures by the CH···O interactions between phenol groups and CH···π interactions between adamantyl and phenol groups (Figure 2).38 Pale yellow single crystals of the racemates (1·2-a) were obtained from a solution of 1 and 2 at a ratio of 1:1 in a mixture of chloroform and methanol. The macrocycles in the crystal (1·2-a) had a rhomboidal framework with the axis longer than those of crystals 1a (Figure 3). The centroid− centroid distances were 12.41 and 13.13 Å for the phenyl rings, 23.48 Å for the cyclohexyl groups, and 12.84 Å for the adamantyl groups. The nitrogen atoms in the imine were separated by 18.62 and 19.04 Å. The dihedral angles between the two phenyl planes were 22.51 and 42.35°. Intramolecular hydrogen bonds between the nitrogen atoms of the imine parts were observed (the distances of the oxygen and nitrogen atoms were 2.59−2.65 Å). The macrocycles were alternatively aligned into the columnar structures by CH···π interactions between the hydrogen atoms of the imine and the phenol groups and between the phenol groups, which were fabricated to afford the network structures through CH···π and CH···O interactions between adamantyl and phenol groups (Figure 4). We investigated the sizes and morphologies of the selfassembled nanostructures until crystal formation by using transmission electron microscopy (TEM). Macrocycle 1 was soluble in chloroform and slightly soluble in methanol. Macrocycle 1 was dissolved in chloroform (0.25 mM) at 40 °C and allowed to stand at 25 °C. After 1 month, crystals were not formed. In contrast, the addition of methanol to a chloroform solution of 1 (methanol/chloroform = 3:1, v/v, 0.25 mM) resulted in crystal formation after 9 h at 25 °C. From TEM observations, a spherical object, with a size of approximately 43 nm, and its regularly fused fibrous and network aggregates appeared after 0.25 h (Figure 5a). Furthermore, from the fast Fourier transform pattern, selfassembled materials containing the spherical particles exhibited

as a precursor was performed according to a previous procedure.30 The condensation reaction of a 1:1 ratio of 3 and (R,R)-1,2-cyclohexanediamine in a mixture of acetonitrile and chloroform at room temperature resulted in the formation of 1 in 65% yield. From the 1H NMR spectrum of 1 in CDCl3, one singlet for the imine protons at 8.13 ppm and one singlet for the hydroxyl protons at 13.27 ppm were observed, which supported that the product was a symmetric cyclic structure. High-resolution mass spectrometry indicated the protonated molecular ion at m/z = 1005.5307 for [M + H]+, which was consistent with the molecular weight of the [2 + 2] condensation product 1 with a formula of C68H68N4O4. Similarly, the macrocycle 2 was constructed from the reaction of 3 and (S,S)-1,2-cyclohexanediamine in 72% yield. The structural characterization of 1 was proved by singlecrystal X-ray crystallographic analysis. Pale yellow single crystals 1a were obtained from 1 in a mixture of methanol and chloroform. The macrocycle was a rhomboidal structure with a cavity (Figure 1). The centroid−centroid distances were 12.61 and 13.41 Å for the phenyl rings, 22.78 Å for the cyclohexyl groups, and 14.27 Å for the adamantyl groups. The nitrogen atoms in the imine parts were separated by 17.97 and 18.29 Å. The dihedral angle between the two phenyl planes B



Article

Figure 2. Packing diagram of 1 in crystal 1a: (a) top and (b) side views of the network structure. Solvent molecules are omitted for clarity.

amorphous properties. The spherical components had a wholly black color, which confirmed the generation of colloidal assemblies (Figure 5b). Thus, the macrocycles were selfassembled into spherical particles, which then were regularly fused into fibrous and network aggregates. In a previous report,30 the adamantane-containing macrocycle produced from ethylenediamine and 3 afforded hollow spherical aggregates in polar organic solutions. Therefore, the sizes and internal characteristics of spherical aggregates rely on the ethylene and cyclohexane linkers in addition to the used organic solvents (Figure S1). As time proceeded, the sizes of the one- or two-dimensional assemblies increased in association with the decrease in the number of spherical particles (Figure 5c). Morphological changes by the fusion of spherical aggregates into fibrous and network aggregates were mostly attributed to hydrogenbonding interactions of multiple hydroxyl groups and the minimization of the surface area of supramolecular assemblies in polar environments. At the initial stages of crystal formation, self-assembled nanostructures and microsized solids appeared, which suggested a phase transition from supramolecular aggregates to crystals. As a result, the addition of methanol into the chloroform solution caused the production of spheres and their fused aggregates, which eventually transformed into crystals, which indicated that the driving forces for crystallization were almost ascribed to the solvent effect (Figure 6).

Crystallization of 1 and 2, a racemic mixture, showed a similar molecular assembly, that is, spherical aggregation, morphological changes, and phase transition from the solution to the crystals; however, the formation time of the racemic crystal (1·2-a) was shorter than that of crystal 1a. Methanol was added into a chloroform solution of 1 and 2 at a ratio of 1:1 (methanol/chloroform = 3:1, v/v, 0.25 mM) at 25 °C. After 0.25 h, the TEM images revealed the fabrication of solid spheres with a size of approximately 60 nm and their fused fibrous and network aggregates (Figure 5d, e). The sizes of the fibrous and network aggregates were larger in comparison with those from the self-assembly process of 1, which meant that the macrocycles smoothly underwent their molecular assembly under these conditions. The TEM images indicated the growth of fibrous and network aggregates built from spherical particles after 1.0 h (Figure 5f). Subsequently, the crystals, by way of self-assembled aggregates, appeared after 4 h (Figure 6). From these experimental outcomes, the faster generation and growth of fibrous and network aggregates resulted in the faster formation of racemic crystals in comparison with those of the homochiral crystals, which was proposed to arise from the network structures originating from the components, as was revealed by X-ray crystallographic analysis. The macrocycles were assembled into brick network architectures possessing layer structures for crystal 1a and a molecular network composed of columnar structures for crystal 1·2-a. The macrocycles in the racemic crystals were closely packed C



Article

Figure 3. Molecular structures of a pair of 1 and 2 in crystal 1·2-a from the top and side views. Solvent molecules are omitted for clarity.

relative to that in crystals 1a in the crystalline solids.39,40 Additionally, approximately two chloroform in crystal 1a and approximately one chloroform in crystal 1·2-a were contained for one molecule of the macrocycle. The polarity in a mixed solution and concentration of macrocycles affect the crystallization rate. The crystals were formed after 2 days in a methanol/chloroform (3:2, v/v) mixture and were not formed after 1 month in methanol/ chloroform (1:2, v/v) mixture of 1 and 2 at a ratio of 1:1 (0.25 mM). In the methanol/chloroform (3:1, v/v) mixture of 1 and 2 at 1:1 stoichiometry (0.50 mM) with a higher concentration, crystals were observed after 1 h. From these findings, the crystallization rate in solution was elevated according to the increase of the polarity in a mixed solution and the concentrations of 1 and 2.

■

self-assembled materials originating from two components may provide detailed valuable information and findings toward the diverse crystallization phenomenon. We are currently working to introduce other chiral groups to macrocyclic tetraimines to investigate their self-assembly behavior and dynamic aspects for crystal formation.

■

EXPERIMENTAL SECTION

General Procedure. All reagents and solvents were obtained from commercial suppliers and used without further purification. The synthesis of compound 3 was performed according to the literature.30 Melting points were determined using an ATM-01 melting temperature measurement device. IR spectra were recorded on a Jasco FT/ IR-6300 spectrometer. 1H and 13C NMR spectral measurements were performed on a Bruker AV400 spectrometer in CDCl3 using tetramethylsilane as the internal standard at 298 K. HRMS measurements of 1 and 2 were carried out using Exactive (Thermo Fisher Scientific) consisting of an Orbitrap analyzer and an electrospray ionization (ESI) source. X-ray crystal structure data were collected using a Bruker D8 VENTURE diffractometer with Cu Kα radiation. The transmission electron microscopy was performed at 120 kV using a JEOL JEM-2100F microscope. A drop of the solution of 1 with or without 2 was placed on a carbon-coated copper grid and dried in vacuo at room temperature for 12 h. Synthesis of Macrocycle 1. Under an argon atmosphere, (R,R)1,2-cyclohexanediamine (22.8 mg, 0.20 mmol) was added into a mixture of chloroform (20.0 mL) and acetonitrile (20.0 mL) of compound 3 (84.9 mg, 0.20 mmol) in one portion. The solution was stirred at room temperature for 3 days under an argon atmosphere. The reaction mixture was evaporated into a concentrated solution

CONCLUSION

We have demonstrated that the enantiomeric macrocyclic tetraimines bearing adamantane parts self-assembled into supramolecular materials in a polar organic solution, which were finally transformed into crystals. A mixture of 1 and 2 at 1:1 stoichiometry supplied racemic crystals. Their selfassembly and crystallization routes were almost to the same as that of crystal 1a; however, the racemic crystals exhibited a faster crystallization rate than that of the homochiral crystals, which was associated with the network structures in the crystalline states. The production of racemic crystals through D



Article

Figure 4. Packing diagram of 1 and 2 in crystal 1·2-a: (a) top and (b) side views of the network structure. Solvent molecules are omitted for clarity. 6.97 (d, J = 8.0 Hz, 4H), 6.87 (s, 4H), 6.77 (d, J = 8.0 Hz, 4H), 3.26− 3.19 (m, 4H), 2.08 (br s, 4H), 2.05 (s, 4H), 1.97 (br d, J = 12.8 Hz, 4H), 1.89 (br s, 20H), 1.74−1.66 (m, 8H), 1.46 (br t, J = 9.6 Hz, 4H). 13C NMR (100 MHz, CDCl3) δ 164.4, 160.5, 131.1, 127.6, 122.2, 119.6, 117.8, 98.8, 79.8, 72.7, 47.1, 41.6, 41.5, 35.1, 32.8, 30.3, 27.9, 24.2. HRMS (ESI, m/z) Calcd for C68H69N4O4 [M + H]+ 1005.5313. Found 1005.5288. Crystallization. Crystals of 1a were obtained from a mixture of methanol and chloroform of 1. Crystals of 1·2-a were produced from a mixture of methanol and chloroform of 1 and 2 at 1:1 stoichiometry. X-ray Crystallography. X-ray data for crystals 1a and 1·2-a were collected on a diffractometer with CMOS detector (Bruker D8 VENTURE PHOTON 100) with monochromated Cu Kα (λ = 1.54178 Å) radiation. All data collection was carried out at 100 K. Structure solution and refinement were performed by using SHELXT2014/5 and SHELXL-2014/7, 2017/1.41,42 Crystallographic Data for 1a. C71.52H74.69Cl7.40N4O5.06, Mr = 1333.49; monoclinic, space group C2, Z = 2, Dcalc = 1.253 g·cm−3, a =

under reduced pressure, and then the products were precipitated. Resultant precipitates were collected by filtration and washed with diethyl ether to give yellow solids (65.3 mg, 0.07 mmol) in 65% yield. Mp > 300 °C (decomposed). FT-IR (ATR, cm−1): 2903, 2853, 1619, 1552, 1502, 1449, 1378, 1190, 969, 880, 811. 1H NMR (400 MHz, CDCl3) δ 13.27 (br s, 4H), 8.13 (s, 4H), 6.97 (d, J = 8.0 Hz, 4H), 6.87 (s, 4H), 6.77 (d, J = 8.0 Hz, 4H), 3.26−3.19 (m, 4H), 2.08 (br s, 4H), 2.05 (s, 4H), 1.97 (br d, J = 13.2 Hz, 4H), 1.89 (br s, 20H), 1.77−1.66 (m, 8H), 1.46 (br t, J = 9.6 Hz, 4H). 13C NMR (100 MHz, CDCl3) δ 164.4, 160.5, 131.1, 127.6, 122.2, 119.6, 117.8, 98.8, 79.8, 72.7, 47.1, 41.6, 41.5, 35.1, 32.8, 30.3, 27.9, 24.2. HRMS (ESI, m/z) Calcd for C68H69N4O4 [M + H]+ 1005.5313. Found 1005.5307. Synthesis of Macrocycle 2. The title compound was synthesized in 72% yield as yellow solids in a similar manner to the preparation of 1, where (S,S)-1,2-cyclohexanediamine was used instead of (R,R)-1,2cyclohexanediamine. Mp > 300 °C (decomposed). FT-IR (ATR, cm−1): 2902, 2853, 1619, 1552, 1502, 1448, 1377, 1190, 969, 881, 811. 1H NMR (400 MHz, CDCl3) δ 13.27 (br s, 4H), 8.13 (s, 4H), E



■

Article

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.cgd.8b01617. 1

H and 13C NMR spectra of compounds 1 and 2, and crystal data (PDF)

Accession Codes

CCDC 1874756 and 1874757 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by emailing [email protected], or by contacting The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: + 44 1223 336033.

■

AUTHOR INFORMATION

Corresponding Authors

*Tel.: +81-87-899-7434. Fax: +81-87-894-0181. E-mail: [email protected] (M.T.). *E-mail: [email protected] (K.Y.). ORCID

Masahide Tominaga: 0000-0003-3199-1882 Masatoshi Kawahata: 0000-0003-2865-4113 Kentaro Yamaguchi: 0000-0002-2629-716X

Figure 5. TEM images obtained from a methanol/chloroform (3:1, v/ v) solution of 1 (0.25 mM) after (a, b) 0.25 h and (c) 1.0 h. TEM images obtained from a methanol/chloroform (3:1, v/v) solution of 1 and 2 at a ratio of 1:1 (0.25 mM) after (d, e) 0.25 h and (f) 1.0 h.

Present Address §

M.K.: Showa Pharmaceutical University, 3−3165 HigashiTamagawagakuen, Machida, Tokyo 194−8543, Japan.

Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS This work was supported by JSPS KAKENHI Grant Number JP16K05801. HRMS was performed at the Center for Analytical Instrumentation, Chiba University.

■

REFERENCES

(1) Morissette, S. L.; Almarsson, Ö .; Peterson, M. L.; Remenar, J. F.; Read, M. J.; Lemmo, A. V.; Ellis, S.; Cima, M. J.; Gardner, C. R. HighThroughput Crystallization: Polymorphs, Salts, Co-Crystals and Solvates of Pharmaceutical Solids. Adv. Drug Delivery Rev. 2004, 56, 275−300. (2) Gal, A.; Weiner, S.; Addadi, L. A Perspective on Underlying Crystal Growth Mechanisms in Biomineralization: Solution Mediated Growth versus Nanosphere Particle Accretion. CrystEngComm 2015, 17, 2606−2615. (3) Lin, N.; Liu, X. Y. Correlation between Hierarchical Structure of Crystal Networks and Macroscopic Performance of Mesoscopic Soft Materials and Engineering Principles. Chem. Soc. Rev. 2015, 44, 7881−7915. (4) Fleischman, S. G.; Kuduva, S. S.; McMahon, J. A.; Moulton, B.; Bailey Walsh, R. D.; Rodríguez-Hornedo, N.; Zaworotko, M. J. Crystal Engineering of the Composition of Pharmaceutical Phases: Multiple-Component Crystalline Solids Involving Carbamazepine. Cryst. Growth Des. 2003, 3, 909−919. (5) Schultheiss, N.; Newman, A. Pharmaceutical Cocrystals and Their Physicochemical Properties. Cryst. Growth Des. 2009, 9, 2950− 2967. (6) Chen, J.; Sarma, B.; Evans, J. M. B.; Myerson, A. S. Pharmaceutical Crystallization. Cryst. Growth Des. 2011, 11, 887−895. (7) Delaire, J. A.; Nakatani, K. Linear and Nonlinear Optical Properties of Photochromic Molecules and Materials. Chem. Rev. 2000, 100, 1817−1845.

Figure 6. Schematic representation of self-assembly behavior and crystal structures of the macrocycles.

23.0934(18), b = 9.2966(7), c = 16.8823(13) Å, β = 102.773(3)°, V = 3534.8(5) Å3, 19682 observed and 4725 independent [I > 2σ(I)] reflections, 441 parameters, 1 restraint, final R1 = 0.0849, wR2 = 0.2292, S = 1.043 [I > 2σ(I)]. CCDC 1874756. Crystallographic Data for 1·2-a. C68.91H68.91Cl2.74N4O4, Mr = 1114.24; triclinic, space group P1̅, Z = 2, Dcalc = 1.226 g·cm−3, a = 12.0075(6), b = 14.2139(7), c = 18.8695(10) Å, α = 95.127(2)°, β = 103.665(2)°, γ = 102.656(2)°, V = 3019.3(3) Å3, 40445 observed and 9935 independent [I > 2σ(I)] reflections, 812 parameters, 18 restraints, final R1 = 0.0471, wR2 = 0.1212, S = 1.032 [I > 2σ(I)]. CCDC 1874757. F



Article

(8) Castet, F.; Rodriguez, V.; Pozzo, J.-L.; Ducasse, L.; Plaquet, A.; Champagne, B. Design and Characterization of Molecular Nonlinear Optical Switches. Acc. Chem. Res. 2013, 46, 2656−2665. (9) Bendikov, M.; Wudl, F.; Perepichka, D. F. Tetrathiafulvalenes, Oligoacenenes, and Their Buckminsterfullerene Derivatives: The Brick and Mortar of Organic Electronics. Chem. Rev. 2004, 104, 4891−4945. (10) Takimiya, K.; Osaka, I.; Mori, T.; Nakano, M. Organic Semiconductors Based on [1]Benzothieno[3,2-b][1]benzothiophene Substructure. Acc. Chem. Res. 2014, 47, 1493−1502. (11) Davey, R. J.; Allen, K.; Blagden, N.; Cross, W. I.; Lieberman, H. F.; Quayle, M. J.; Righini, S.; Seton, L.; Tiddy, G. J. T. Crystal Engineering − Nucleation, the Key Step. CrystEngComm 2002, 4, 257−264. (12) Vekilov, P. G. Dense Liquid Precursor for the Nucleation of Ordered Solid Phases from Solution. Cryst. Growth Des. 2004, 4, 671−685. (13) Vekilov, P. G. Nucleation. Cryst. Growth Des. 2010, 10, 5007− 5019. (14) Aakeröy, C. B.; Seddon, K. R. The Hydrogen Bond and Crystal Engineering. Chem. Soc. Rev. 1993, 22, 397−407. (15) Nassimbeni, L. R. Physicochemical Aspects of Host-Guest Compounds. Acc. Chem. Res. 2003, 36, 631−637. (16) Desiraju, G. R. Crystal Engineering: From Molecule to Crystal. J. Am. Chem. Soc. 2013, 135, 9952−9967. (17) Erdemir, D.; Lee, A. Y.; Myerson, A. S. Nucleation of Crystals from Solution: Classical and Two-Step Models. Acc. Chem. Res. 2009, 42, 621−629. (18) Davey, R. J.; Schroeder, S. L. M.; ter Horst, J. H. Nucleation of Organic CrystalsA Molecular Perspective. Angew. Chem., Int. Ed. 2013, 52, 2166−2179. (19) ten Wolde, P. R.; Frenkel, D. Enhancement of Protein Crystal Nucleation by Critical Density Fluctuations. Science 1997, 277, 1975− 1978. (20) Haas, C.; Drenth, J. The Interface between a Protein Crystal and an Aqueous Solution and Its Effects on Nucleation and Crystal Growth. J. Phys. Chem. B 2000, 104, 368−377. (21) Jeon, Y.-M.; Heo, J.; Mirkin, C. A. Dynamic Interconversion of Amorphous Microparticles and Crystalline Rods in Salen-Based Homochiral Infinite Coordination Polymers. J. Am. Chem. Soc. 2007, 129, 7480−7481. (22) Umemura, A.; Diring, S.; Furukawa, S.; Uehara, H.; Tsuruoka, T.; Kitagawa, S. Morphology Design of Porous Coordination Polymer Crystals by Coordination Modulation. J. Am. Chem. Soc. 2011, 133, 15506−15513. (23) Son, D. H.; Hughes, S. M.; Yin, Y.; Alivisatos, A. P. Cation Exchange Reactions in Ionic Nanocrystals. Science 2004, 306, 1009− 1012. (24) Langille, M. R.; Zhang, J.; Personick, M. L.; Li, S.; Mirkin, C. A. Stepwise Evolution of Spherical Seeds into 20-Fold Twinned Icosahedra. Science 2012, 337, 954−957. (25) Schwahn, D.; Ma, Y.; Cölfen, H. Mesocrystal to Single Crystal Transformation of D,L-Alanine Evidenced by Small Angle Neutron Scattering. J. Phys. Chem. C 2007, 111, 3224−3227. (26) Harano, K.; Homma, T.; Niimi, Y.; Koshino, M.; Suenaga, K.; Leibler, L.; Nakamura, E. Heterogeneous Nucleation of Organic Crystals Mediated by Single-Molecule Templates. Nat. Mater. 2012, 11, 877−881. (27) Wang, Y.; Tang, L.; Yu, J. Investigation of Spontaneous Transition from Low-Molecular-Weight Hydrogel into Macroscopic Crystals. Cryst. Growth Des. 2008, 8, 884−889. (28) Moffat, J. R.; Smith, D. K. Metastable Two-Component Gel Exploring the Gel−Crystal Interface. Chem. Commun. 2008, 2248− 2250. (29) Tominaga, M.; Kunitomi, N.; Katagiri, K.; Itoh, T. Adamantane-Based Oxacyclophanes Containing Pyrazines: Synthesis, Crystal Structure, and Self-Assembly Behavior. Org. Lett. 2015, 17, 786−789.

(30) Tominaga, M.; Takahashi, E.; Ukai, H.; Ohara, K.; Itoh, T.; Yamaguchi, K. Solvent-Dependent Self-Assembly and Crystal Structures of a Salen-Based Macrocycle. Org. Lett. 2017, 19, 1508− 1511. (31) Huang, J.; Yu, L. Effect of Molecular Chirality on Racemate Stability: α-Amino Acids with Nonpolar R Groups. J. Am. Chem. Soc. 2006, 128, 1873−1878. (32) Gavezzotti, A.; Rizzato, S. Are Racemic Crystals Favored over Homochiral Crystals by Higher Stability or by Kinetics? Insights from Comparative Studies of Crystalline Stereoisomers. J. Org. Chem. 2014, 79, 4809−4816. (33) Borisova, N. E.; Reshetova, M. D.; Ustynyuk, Y. A. Metal-Free Methods in the Synthesis of Macrocyclic Schiff Bases. Chem. Rev. 2007, 107, 46−79. (34) Belowich, M. E.; Stoddart, J. F. Dynamic Imine Chemistry. Chem. Soc. Rev. 2012, 41, 2003−2024. (35) Hodačová, J.; Buděsí̌ nský, M. New Synthetic Path to 2,2’Bipyridine-5,5′-dicarbaldehyde and Its Use in the [3 + 3] Cyclocondensation with trans-1,2-Diaminocyclohexane. Org. Lett. 2007, 9, 5641−5643. (36) Feng, H.-T.; Zheng, Y.-S. Highly Sensitive and Selective Detection of Nitrophenolic Explosives by Using Nanospheres of a Tetraphenylethylene Macrocycle Displaying Aggregation-Induced Emission. Chem. - Eur. J. 2014, 20, 195−201. (37) Cooper, A. I. Porous Molecular Solids and Liquids. ACS Cent. Sci. 2017, 3, 544−553. (38) Banthia, S.; Samanta, A. Long and Short Brick Network Architecture: Role of Water Molecules Acting as Three-Connecting Spacers. Cryst. Growth Des. 2006, 6, 360−362. (39) Brock, C. P.; Schweizer, W. B.; Dunitz, J. D. On the Validity of Wallach’s Rule: On the Density and Stability of Racemic Crystals Compared with Their Chiral Counterparts. J. Am. Chem. Soc. 1991, 113, 9811−9820. (40) Steed, K. M.; Steed, J. W. Packing Problems: High Z’ Crystal Structures and Their Relationship to Cocrystals, Inclusion Compounds, and Polymorphism. Chem. Rev. 2015, 115, 2895−2933. (41) Sheldrick, G. M. SHELXT − Integrated Space-Group and Crystal-Structure Determination. Acta Crystallogr., Sect. A: Found. Adv. 2015, A71, 3−8. (42) Sheldrick, G. M. Crystal Structure Refinement with SHELXL. Acta Crystallogr., Sect. C: Struct. Chem. 2015, C71, 3−8.

G


Self-Assembly Behavior Shifting to Crystal Formation of Chiral

Recommend Documents