Chiral Nanomaterials ebook

Table of Contents

Cover

Title Page

Copyright

Chapter 1: An Introduction to Chiral Nanomaterials: Origin, Construction, and Optical Application

1.1 Introduction

1.2 Chiral Noble Metal Clusters

1.3 Chiral Plasmonic Nanostructures

1.4 Optical Application of Chiral Noble Metal Nanostructures

1.5 Perspectives

References

Chapter 2: Chirality at Nanoscale – Theory and Mechanism

2.1 Introduction

2.2 Brief Introduction to the Theoretical Background

2.3 The Twist Rod Model

2.4 Induced Chirality in Hybrid Nanostructures Made of Chiral Molecules and QDs

2.5 Induced Chirality in Hybrid Nanostructures Made of Chiral Molecules and Metal Nanoparticles

2.6 Induced Chirality in Hybrid Nanostructures Made of Chiral Quantum Dots and Metal Nanoparticles

References

Chapter 3: Plasmonic Chiral Materials

3.1 Introduction

3.2 Fabrication of Plasmonic Chiral Nanomaterials

3.3 Properties of Plasmonic Chiral Nanomaterials

3.4 Applications of Plasmonic Chiral Nanomaterials

3.5 Conclusions

Acknowledgments

References

Chapter 4: Optically Active and Chiral Semiconductor Nanocrystals

4.1 Introduction

4.2 Chiroptically Active Excitonic Nanocrystals

4.3 Effects That Emerge from Chiral Arrangement of Nanocrystals

4.4 Nanocrystals with Chiral Crystal Symmetry (Chiral Atomic Arrangement)

4.5 Nanostructures with Chiral Shape

4.6 Summary and Outlook

References

Chapter 5: Chirality in Gold Nanoclusters

5.1 Introduction

5.2 The Origin of Chirality in Au

n

(SR)

m

Nanoclusters

5.3 X-ray Structures of Chiral Au

n

(SR)

m

Nanoclusters

5.4 Separation of Racemic Gold Nanoclusters and Their Chiroptical Properties

5.5 Other Chirality Origins in Gold Nanoclusters

5.6 Conclusion

Acknowledgment

References

Chapter 6: Chiral Mesoporous Silica Materials

6.1 Introduction

6.2 Chiral Mesoporous Materials Templated by Artificial Amphiphiles

6.3 Chiral Mesoporous Materials Template by DNA

6.4 Chiral Mesoporous Materials Templated by Peptides

6.5 Chiral Mesoporous Materials Templated by Polysaccharides

6.6 Summary and Outlook

References

Chapter 7: DNA-Based Chiral Nanostructures

7.1 Introduction

7.2 Preparation of DNA-Directed Chiral Nanostructures

7.3 Typical Chiral Nanocrystals and Nanoassemblies

7.4 Origin of Chiroplasmonic Activities

7.5 Conclusions

References

Chapter 8: Applications in Catalysis

8.1 Introduction

8.2 Asymmetric Hydrogenation Reactions Catalyzed by Chiral Metal Nanoparticles

8.3 Asymmetric C−C Bond-Forming Reactions Catalyzed by Chiral Metal Nanoparticles

8.4 Summary

References

Chapter 9: Applications in Polymer Science

9.1 Introduction

9.2 Preparation of Chiral Polybissilsesquioxanes

9.3 Characterization of Chiral Polybissilsesquioxanes

9.4 Applications of Chiral Polybissilsesquioxanes

9.5 Conclusion

References

Index

End User License Agreement

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Guide

Cover

Table of Contents

Begin Reading

List of Illustrations

Chapter 1: An Introduction to Chiral Nanomaterials: Origin, Construction, and Optical Application

Figure 1.1 Scheme of chiral organic molecules.

Figure 1.2 (a) Structure of chiral l/d-penicillamine, (b) electrophoresis separation of Au clusters, (c) temperature-dependent CD response. (Yao

et al

. 2005 [45] and Yao

et al

. 2007 [46]. Reproduced with permission of American Chemical Society.)

Figure 1.3 Nanoparticles with chiral morphology. (Fan and Govorov 2012 [60]. Reproduced with permission of American Chemical Society.)

Figure 1.4 Coupling model of chiral molecules and plasmonic nanoparticles. (a) Absorption spectrum of metal nanoparticles, (b) field enhancement effect, (c) chiral signal of chiral molecules, (d) coupling between chiral molecules and plasmonic nanoparticles. (Govorov 2011 [62]. Reproduced with permission of American Chemical Society.)

Figure 1.5 Different types of chiral assembly. (Fan and Govorov 2010 [67]. Reproduced with permission of American Chemical Society.)

Figure 1.6 Chiral dimmer of ellipsoid nanoparticles (a) and LSPR hybridization (b) with symmetric mode ω+ and an antisymmetric mode ω−. (Auguie

et al

. 2011 [69]. Reproduced with permission of American Chemical Society.)

Figure 1.7 (a) Low and (b) high magnification of Ag nanoparticles and (c) corresponding CD spectrum. (Shemer

et al

. 2006 [72]. Reproduced with permission of American Chemical Society.)

Figure 1.8 Scheme of chiral plasmonic assembly based on the polymer scaffold with extraordinary optical activity [81]. (Oh

et al

. 2010 [81]. Reproduced with permission of American Chemical Society.)

Figure 1.9 (a) Scheme, (b) transmission electron microscopy, and (c) CD spectrum of chiral assembly of Au nanoparticles and amphiphilic peptides. (Song

et al

. 2013 [84]. Reproduced with permission of American Chemical Society.)

Figure 1.10 DNA-induced chiral assembly of plasmonic nanoparticles. (a) Pyramid of four different types of nanoparticles (Au nanoparticles of two sizes, Ag nanoparticles and quantum dots). (Yan

et al

. 2012 [92]. Reproduced with permission of American Chemical Society). (b) Au nanorod dimmers on planar DNA origami. (Lan

et al

. 2013 [93]. Reproduced with permission of American Chemical Society.)

Figure 1.11 (A) Scheme and (B) TEM images of dynamic chiral assembly of nanoparticles. (Shen

et al

. 2011 [99]. Reproduced with permission of American Chemical Society.)

Figure 1.12 Chiral channel-induced Ag nanoparticle assembly. (Xie

et al

. 2012 [104]. Reproduced with permission of Wiley.)

Figure 1.13 Au [email protected] core–shell nanoparticles and its application in chiral recognition. (Liu

et al

. 2013 [106]. Reproduced with permission of American Chemical Society.)

Figure 1.14 (a) Typical SEM and (b) TEM images (a, b) of chiral Au nanorod assembly and its corresponding (c) CD signal and (d) UV–vis spectrum. (Guerrero-Martinez

et al

. 2011 [80]. Reproduced with permission of Wiley.)

Figure 1.15 Scheme of detection strategy based on (a) immune-recognition. (Xu

et al

. 2012 [108]. Reproduced with permission of Royal Society of Chemistry.) and (b) DNA detection. (Li

et al

. 2012 [109]. Reproduced with permission of American Chemical Society.)

Chapter 2: Chirality at Nanoscale – Theory and Mechanism

Figure 2.1 Schematic diagram of the twist rod model.

Figure 2.2 (a) Schematic diagram of the twist rod system and its mirror system. (b) The CD spectra of mirror systems are of the same amplitude and opposite sign. The size of the nanorod is 30 nm × 30 nm × 60 nm. The nanorod center distance

R

= 90 nm.

Figure 2.3 The

g

-factors versus wavelength for twist rods with different aspect ratios. The aspect ratio of one twist rod system (30 nm × 30 nm × 60 nm) is 2 : 1, the aspect ratio of the other twist rod system (30 nm × 30 nm × 90 nm) is 3 : 1. The nanorod center distance

R

= 90 nm. The twist angle .

Figure 2.4 The CD of twist rod system versus twist angle. The particle size is 30 nm × 30 nm × 60 nm and the nanorod center distance

R

= 90 nm. The wavelength is 579 nm.

Figure 2.5 The

g

-factors for twist rod systems with different interrod distances

R

= 66 nm and

R

= 108 nm. The size of the nanorod is 30 nm × 30 nm × 60 nm and the twist angle . The system with a smaller interrod distance has larger

g

-factors.

Figure 2.6 (a) Schematic diagram of the extended twist rod model to illustrate the basic mechanism of induced chirality. Here, the chiral subsystem in the box (with two nanorods with size 20 nm × 20 nm × 30 nm and twist angle with the surface distance of 10 nm) induces chiral response of the other larger nanorod 105 nm away (with size 30 nm × 30 nm × 90 nm and the corresponding absorption peak at 670 nm). (b) The CD spectrum of the extended twist rod system. Strong CD signal appears at 670 nm, the plasmonic resonance wavelength of the larger nanorod.

Figure 2.7 CD spectra of (a) d-GSH stabilized CdTe QDs at low concentration, and (b–e) size-dependent CD spectra and corresponding UV/vis spectra of d-GSH-stabilized CdTe QDs of different sizes at high concentrations. The inset in (a) shows the enlarged part in the UV light region.

Figure 2.8 (a) CD spectra of hybrid structures with MNRs of different aspect ratios; (b) CD spectra of hybrid structures with QDs of different sizes.

Chapter 3: Plasmonic Chiral Materials

Figure 3.1 Schematic illustration of the emergence of new field that relates chirality to plasmonics. ((a) Adapted from Grande and Patel 2009 [5]. Reproduced with permission of Macmillan Publishers Ltd.); ((b) Adapted from Juan

et al

. 2011 [10]. Reproduced with permission of Macmillan Publishers Ltd.)

Figure 3.2 (a) Schematic of preparation of chiral plasmonic composites by using assembled nanocrystalline cellulose as the template; scanning electron microscopy (SEM) image of prepared composite films with Au nanorod loading concentration of (b) 0 wt%, (c) 0.12 wt%, and (d) 3.39 wt%. (Adapted from Querejeta-Fernández

et al

. 2014 [23]. Reproduced with permission of American Chemical Society.)

Figure 3.3 (a) Schematic illustration of chiral nematic ordering in NCC with a half pitch

P

/2 of 150–650 nm; (b–d) polarized optical microscopy image of TEOS/NCC during slow evaporation, silica/NCC composite film, and mesoporous silica after calcination; (e) top view of a cracked film showing the relatively smooth top surface and a layered structure looking down the edge (scale bar, 10 mm). (f) Side view of a cracked film showing the stacked layers that result from the helical pitch of the chiral nematic phase (scale bar, 3 mm). ((a–f) Adapted from Shopsowitz

et al

. 2010 [24]. Reproduced with permission of Nature Publishing Group.). (g) Photograph of HAuCl

4

-loaded NCC/SiO

2

composite films. (h) Photograph of pink Au- and yellow Ag-decorated films. ((g, h) Adapted from Kelly

et al

. 2012 [25]. Reproduced with permission of American Chemical Society.)

Figure 3.4 (a) Schematic of preparation of chiral metal nanoparticle superstructures with chiral mesoporous silica (CMS) as the template. Ag nanoparticles were assembled on the as-synthesized (Ag–CMS-as), calcinated (Ag–CMS-cal) and extracted (Ag–CMS-ex) CMS templates showing three different types of chirality. (b) High-resolution transmission electron microscopy (HRTEM) images of L- and R-Ag-CMS-as. (c) HRTEM images of L- and R-Ag-CMS-cal; (d) HRTEM images of L- and R-Ag–CMS-ex. (Adapted from Xie

et al

. 2012 [27]. Reproduced with permission of Wiley.)

Figure 3.5 (A) Schematic illustration of the experimental scheme. (B) TEM images of the tubular DNA origami dressed with gold nanoparticles, which form 3D gold nanoparticle helices. (C) Histograms of the number of gold nanoparticles assembled on the tubular DNA origami. (Adapted from Shen

et al

. 2011 [36]. Reproduced with permission of American Chemical Society.)

Figure 3.6 (a) Schematic illustration of l- and d-isomers of diphenylalanine peptide nanotube (PNT). TEM images of PNT in the (b) absence and (c) presence of EG–Au nanoparticles. (d) High-magnification TEM image of PNTs with gold nanoparticle bunches attached to the surface (the inset HRTEM shows one of the bunches). (Adapted from George and Thomas 2010 [42]. Reproduced with permission of American Chemical Society.)

Figure 3.7 (a) Schematic depiction of the synthetic procedure of gold nanoparticle double helices. TEM images and 3D surface renderings of the tomographic volumes of left-handed and right-handed (b–d and e–g, respectively) gold helices (scale bars: b, e, 200 nm; c, f, 20 nm). (Adapted from Song

et al

. 2013 [22]. Reproduced with permission of American Chemical Society.)

Figure 3.8 (a) Schematic routes for preparation of 3D metamaterials with continuous gyroid networks. (Adapted from Vignolini

et al

. 2012 [55]. Reproduced with permission of Wiley.). (b, c) SEM images of gold gyroid metamaterials obtained from terpolymers of different molecular weights yielding lattice constant of 35 and 50 nm, respectively. (Adapted from Salvatore

et al

. 2013 [56]. Reproduced with permission of Wiley.)

Figure 3.9 (a) Chemical structure of gelator and chiral components. (b) Schematic of preparation of chiral gold nanoparticle plasmonic superstructures directed by gelator assembly. (c) AFM images showing left-handed and right-handed hydrogel nanofibers. (Adapted from Jung

et al

. 2014 [57]. Reproduced with permission of American Chemical Society.)

Figure 3.10 (a) Chemical structure of the anthraquinone-based oxalamide. The asymmetric carbon atom is being labeled by star sign. (b, c) Scanning electron microscopy (SEM) graphs of the P and M fibers, respectively. (d) SEM image of the P bulk nanocomposite. ((a–d) Adapted from Guerrero-Martínez

et al

. 2011 [13]. Reproduced with permission of Wiley.). (e) Schematic illustration of chiral assembly of surfactant-capped gold nanorods through supramolecular-template method. (f) Cryo-TEM image for the helical arrangement of gold NRs. Scale bar, 500 nm. ((e, f) Adapted from Wang

et al

. 2011 [58]. Reproduced with permission of Royal Society of Chemistry.)

Figure 3.11 (a) Schematics for PCR-based Au nanorods SBS assembly. PCR replication procedure in which a DNA strand can be amplified using primer, template DNA, taq plus polymerase and four different DNA bases. (b) TEM image for SBS assemblies obtained after 15 h. Scale bar, 50 nm. Cryo-TEM tomography images for SBS nanorods (c) trimer and (d) pentamer. Scale bar, 25 nm. (Adapted from Ma

et al

. 2013 [60]. Reproduced with permission of Nature Publishing Group.)

Figure 3.12 (a) Schematic illustration of the formation of double helix. TEM image of (b) the as-synthesized Au/Ag NWs, and (c) a typical (Au/Ag)@Pd double helix. (Adapted from Wang

et al

. 2011 [62]. Reproduced with permission of American Chemical Society.)

Figure 3.13 (a) Schematic illustration of reversible plasmonic CD responses based on temperature-dependent dynamic assembly and disassembly of double-strand-DNA-modified gold nanorods (orange column). (b) Reversible plasmonic CD of DNA-modified gold nanorods at 20 °C (black line) and 60 °C (red line). (c) CD intensity of gold nanorods capped with double-strand DNA at the wavelength of 750 nm cycled at 20 °C (black squares) and 60 °C (red dots). (Adapted from Li

et al

. 2012 [63]. Reproduced with permission of American Chemical Society.)

Figure 3.14 (a) Schematic illustration (top) and SEM image (bottom) of gold nanoparticle (14 nm) arrays by using micellar nanolithography. (b) Schematic illustration of DSG method. (c) Schematic illustration of array of complex 3D structures by using DSG. (d) TEM image of hybrid insulator–metal nanohooks. (e) Model of the designed structure, TEM image showing the grown structure and optical image of solution with dispersed nanoparticles. (Adapted from Mark

et al

. 2013 [67]. Reproduced with permission of Nature Publishing Group.)

Figure 3.15 Circular dichroism spectra and schematic illustration of self-assembled pyramids with (a, b) four 10 nm gold nanoparticles (type 1) and three 15 nm gold nanoparticles + 25 nm gold nanoparticle (type 2); (c, d) two 15 nm gold nanoparticles + two quantum dots (type 3), and 15 nm gold nanoparticles + 25 nm gold nanoparticle + two quantum dots (type 4) [inset: CD spectra in the 300–450 nm region]; and (e, f) 15 nm gold nanoparticles + 25 nm gold nanoparticle + silver nanoparticle + quantum dot as

S

- (type 5) and

R

-enantiomers (type 6). (Adapted from Yan

et al

. 2012 [76]. Reproduced with permission of American Chemical Society.)

Figure 3.16 Circular dichroism of self-assembled right- (left-) handed 10 nm (a, b) or larger (c, d) gold particle helices gold nanohelices in experiment (a, c) and theory (b, d). Inset: TEM images (scale bar, 20 nm). (Adapted from Kuzyk

et al

. 2012 [21]. Reproduced with permission of Nature Publishing Group.)

Figure 3.17 (a) Schematic depiction of the gold nanoparticle double helix with relevant metrics indicated. (b) CD spectra of left- and right-handed gold nanoparticle double helices before and after gold enhancement. Left-handed gold helices without gold enhancement (blue); right-handed gold helices without gold enhancement (red); gold enhanced left-handed gold helices (orange); gold enhanced right-handed gold helices (green). (c) Simulation of the effect of sphere diameter on CD response. The sphere diameter was sampled at 7.0, 8.0, 9.0, and 11.0 nm. The other parameters remained constant. (d) Simulation of the effect of interhelical spacing on CD response. The interhelical distance was sampled at 4.0, 7.0, and 10.0 nm. The other parameters remained constant. (e) Simulation of the effect of interparticle distance on CD response. The interparticle distance was sampled at 1.0, 1.5, and 2.0 nm. The other parameters remained constant. (Adapted from Song

et al

. 2013 [22]. Reproduced with permission of American Chemical Society.)

Figure 3.18 (a) Experimental CD spectra of right-handed (P; red) and left-handed (M; blue) nanocomposites. Solid lines represent the twist bundles composed of gold NRs (length 45 nm, width 17 nm); dashed lines show the twist bundles composed of gold nanospheres (diameter 15 nm). (b) Gold NRs are attached to the surface of the cylinder and arranged in a helical way. The inset is a represented model of chiral nanocomposites. (c) Simulated CD and (d) molar extinction coefficient using the coupled dipole model described. (e) g-factors of various chiral NP systems. (f) Evolution of the g-factor with the concentration of gold NR. (Adapted from Guerrero-Martínez

et al

. 2011 [13]. Reproduced with permission of Wiley.)

Figure 3.19 Schematic illustration and corresponding CD spectra of end-to-end and side-by-side assemblies of gold nanorods. (Han

et al

. 2014 [61]. Reproduced with permission of American Chemical Society.)

Figure 3.20 Schematic routes for preparation of 3D metamaterials with continuous gyroid networks: (a) double gyroid; (b) hollow double gyroid; (c) alternating gyroid; (d) normalized near-field profiles (yellow = 1, black = 0) and energy flux (arrows) of silver, aluminum, and gold; (e) far-field simulation results of electric field polarization rotation angle for the Au Drude metal (black) and silver (red) of a A-GYR slab composed of two unit cells. (f) Reflectance (solid lines) and transmittance (broken lines) of the slab. (Adapted from Hur

et al

. 2011 [77]. Reproduced with permission of Wiley.)

Figure 3.21 (a) Experimental setup to measure magnetochiral dichroism. (b) Magnetization curve measured parallel to the axis of the left-handed Ni nanohelices measured with a superconducting quantum interference device (SQUID) magnetometer. The inset plot shows the wide field magnetization curve. The inset SEM shows the cross section of arrays of nickel two-turn chiral nanostructure. (c) Natural circular dichroism spectra of two-turn Ni nanohelices with left-handedness (red) and right-handedness (black). (d) Magnetic circular dichroism (MCD) of unstructured plain film (blue) and left-handedness (red) and right-handedness (black) of Ni nanohelices at −0.3 T (squares), 0.0 T (triangles), and +0.3 T (circles), respectively. (e) Magnetochiral dichroism (MchD) of left-handed (red) and right-handed (black) nanohelix arrays at magnetic field strengths of 0.08 and 0.16 T. (Eslami

et al

. 2014 [78]. Reproduced with permission of American Chemical Society.)

Figure 3.22 (a) Detection of MCLR by chiral plasmonic technique. The CD and UV–vis absorption curves with increasing concentrations of MCLR solution. (b) Calibration curves for MCLR detection, obtained for ΔCD = (CD

526 nm

− CD

399 nm

) and

A

= (

A

523 nm

+

A

404 nm

) as a function of logarithmic MCLR concentrations. ((a, b) Adapted from Wang

et al

. 2010 [88]. Reproduced with permission of Wiley. (c) Schematic of the assembled heteropyramid NPs. Adapted from Yan

et al

. 2015 [89]. Reproduced with permission of Elsevier.)

Chapter 4: Optically Active and Chiral Semiconductor Nanocrystals

Figure 4.1 (a) Absorption spectra (and onset of emission spectra) of CdS nanocrystals stabilized with d-penicillamine (blue), l-penicillamine (green), and

rac

-penicillamine (red). Excitation wavelength for all emission spectra is 365 nm. (b) CD spectra of the d-, l-, and

rac

-penicillamine-stabilized CdS QDs.

Figure 4.2 (a) Ideal tetrahedron of CdTe NCs used in calculations and (b) model of the chiral tetrahedral apex: Cd (green); Te (brown); O (red); S (cyan). (Zhou

et al

. 2010 [7]. Reproduced with permission of American Chemical Society.) (c) Top and side views of the proposed bonding of d-penicillamine to the surface of wurtzite (Cd = brown, S = yellow, C = gray, O = red, N = blue, H = white, balls = topmost atoms). In the top view, horizontal rows of vertical CdS units are visible at the top and bottom of the figure, and surface S atoms have been removed from the middle row and one has been replaced by the S atom of d-penicillamine, so as to illustrate the bonding pattern found in this study.

Figure 4.3 (a) Photoluminescence and (b) CPL spectra of apoferritin (blue) and [email protected] (red). All spectra were obtained using excitation at 325 nm. Photographs of (c) apoferritin and (d) [email protected] (e) Kuhn's anisotropy factor (

g

Lum

) as a function of wavelength.

Figure 4.4 (a) Normalized CD spectra of l-cysteine capped CdSe QDs of different radii (2.5, 3.0, and 3.3 nm). The particles were synthesized with achiral surfactants, which were later exchanged to cysteine. (Tohgha

et al

. 2013 [11, 12]. Reproduced with permission of Royal Society of Chemistry.) (b) CPL (upper curves) and total luminescence (lower curve) spectra of aqueous solution l-Cys-CdSe (red dots, Ø = 2.9 nm) and d-Cys-CdSe (blue dots, Ø = 2.9 nm) QDs ([CdSe] = 1 mM, 295 K), upon excitation at 451 nm, respectively.

Figure 4.5 (A, B) High-resolution TEM images of individual NCs; blue arrows mark the

c

-axis direction of the NC. Scale bars are 5 nm. In (A), a sketch of a single Hg–S helix (not to scale) has been placed on the image to correlate the direction of the Hg–S spirals with the crystal

c

axis. (C) Schematic illustration of the opposite spirals of atoms with a fraction of one spiral reconstructed inside the frame of the hexagonal unit cell.

Figure 4.6 (a) A 3D reconstruction from a electron holography experiment of a chiral tellurium nanostructure and (b) a computer model of its chiral geometry. (c) Experimental versus simulated CD dissymmetry spectra for two sizes of these chiral Te nanostructures.

Chapter 5: Chirality in Gold Nanoclusters

Figure 5.1 A cartoon structure of the Au

n

(SR)

m

nanoclusters illustrating the inner core (i.e., kernel), the Au–S interface, and the outermost carbon tails.

Figure 5.2 Three possible origins of chirality in the Au

n

(SR)

m

nanoclusters.

Figure 5.3 Structurally characterized magic sizes of Au

n

(SR)

m

nanoclusters. The chiral ones are highlighted in red.

Figure 5.4 The chiral structure of the Au

20

(SPh-

t

-Bu)

16

nanocluster. (a–d) Structure anatomy of the Au

20

(SR)

16

nanocluster. (e) Chiral structures of the two enantiomers. Magenta: Au atoms in the kernel. Blue: Au atoms at the surface. Yellow: sulfur. Carbon tails are omitted for clarity.

Figure 5.5 Chiral structure of the Au

28

(SPh-

t

-Bu)

20

nanocluster. Magenta: Au in the kernel. Blue: Au in the surface. Yellow: sulfur. Carbon tails are omitted for clarity.

Figure 5.6 Achiral structure of the Au

36

(SPh-

t

-Bu)

24

nanocluster. (a) From left to right, Au

20

kernel in Au

28

(SR)

20

, Au

28

kernel in Au

36

(SR)

24

, and the proposed Au

36

kernel in Au

44

(SR)

28

. (b) Chiral Au

28

S

20

framework and achiral Au

36

S

24

framework.

Figure 5.7 Chiral structure of the Au

38

(SCH

2

CH

2

Ph)

24

nanocluster. (a) Au

23

kernel formed by face fusion of two icosahedra. (b) Two chiral Au

38

(SR)

24

isomers. Magenta: Au in the kernel. Blue: Au in the surface. Yellow: sulfur. Carbon tails are omitted for clarity.

Figure 5.8 Achiral structure of the Au

25

(SCH

2

CH

2

Ph)

18

nanocluster. (a) Au

13

icosahedral kernel. (b) Au

25

S

18

framework. (c) The different rotation directions of the dimeric staple motifs on the opposite pole cancel out the chirality, making Au

25

S

18

a mesomer. Magenta: Au in the kernel. Blue: Au in the surface. Yellow: sulfur. Carbon tails are omitted for clarity. Redrawn from the cif file of Au

25

(SR)

18

.

Figure 5.9 Chiral structure of the Au

102

(SPh-

p

-COOH)

44

nanocluster. Magenta: Au in the kernel. Blue: Au in the surface. Yellow: sulfur. Carbon tails are omitted for clarity. Redrawn from the cif file of Au

102

(SR)

44

.

Figure 5.10 The Au

107

kernel structure of the Au

133

(SR)

52

nanocluster.

Figure 5.11 Chirality in the Au

133

(SPh-

t

-Bu)

52

nanocluster induced by chiral arrangement of –S–Au–S– staples at the Au–S interface (a–d).

Figure 5.12 Chirality in Au

133

(SPh-

t

-Bu)

52

nanocluster induced by chiral arrangement of carbon tails on the surface.

Figure 5.13 Separation of racemic Au

38

(SR)

24

nanoclusters by chiral-HPLC. (a) HPLC chromatogram; (b) UV–vis absorption spectra; (c) CD spectra; (d) the corresponding anisotropy factor.

Figure 5.14 Separation of racemic Au

28

(SR)

20

nanoclusters by chiral HPLC. (a) Structure of two isomers; (b) CD spectra of separated enantiomers; (c) UV–vis spectra.

Figure 5.15 (a) CD spectra of Au

25

(SR)

18

protected by left- and right-handed PET* ligands. (b) Cartoon of the Au

25

(PET*)

18

nanocluster.

Figure 5.16 The influence of the type of chiral ligand on the CD spectra of Au

25

(SR)

18

(a–c).

Figure 5.17 The structure of the chiral [Au

20

(PP

3

)

4

]

4+

cluster. (a) Top view of the chiral Au

20

kernel; (b) side view; (c) overview of PP

3

ligand bonding on the Au

20

kernel. Magenta: Au in the kernel. Green: Au in the Au

7

unit. Orange: phosphine; Gray: carbon. Redrawn from the cif file of the [Au

20

(PP

3

)

4

]

4+

cluster.

Figure 5.18 Chiroptical signals of [Au

11

(

R

-BINAP)

4

X

2

]

+

and [Au

11

(

S

-BINAP)

4

X

2

]

+

enantiomers and achiral [Au

11

(PPh

3

)

8

X

2

]

+

clusters.

Chapter 6: Chiral Mesoporous Silica Materials

Figure 6.1 Different interactions between the surfactants and the polymerized silica precursors. (Qiu and Che 2011 [22]. Reproduced with permission of Royal Society of Chemistry.)

Figure 6.2 (a

1

) Chiral diaminocyclohexane-based organogel molecules. (a

2

and a

3

) SEM and TEM images of the left-handed silica transcripted by molecule 1 + 2. (Seddon

et al

. 2002 [24]. Reproduced with permission of Wiley.) (b

1

) Chiral molecule, 1,2-bis(10,12-tricosadiyonyl)-

sn

-glycero-3-phosphatidylcholine. (b

2

and b

3

) TEM images of the silica–lipid helical tubules and ribbons, the tubule edge showing lattice fringes corresponding to a lamellar hybrid mesostructures. Scale bar = 50 nm. (Jung

et al

. 2000 [25]. Reproduced with permission of American Chemical Society.)

Figure 6.3 Schematic illustration of the two types of interaction between the head group of C14-l-AlaS with TMAPS (a

1

), and C14-l-AlaA with APS (a

2

). (b

1

–b

5

) Morphology and mesostructure of a typical CMS. (Che

et al

. 2004 [30]. Reproduced with permission of Nature Publishing Group.)

Figure 6.4 (a) Schematic drawing of a “twisted tube.” (b) Chiral channels with the twisted tube marked by colored lines. (c) The cross section of the tube. (d) Schematic drawing of a “spiral tube.” (Ohsuna

et al

. 2005 [31]. Reproduced with permission of Wiley.)

Figure 6.5 (a) Illustration of the formation of different kinds of silica nanostructures using the chiral cationic surfactants as templates via the sol–gel method. (b) SEM images of the corresponding left-handed twisted mesoporous silica naonribbons (b

1

), left-handed double-helical mesoporous silica nanofibers (b

2

), left-handed single-stranded loosely coiled silica nanofibers (b

3

), and double twisted silica nanoribbons (b

4

). (Yang

et al

. 2006 [32]. Reproduced with permission of Royal Society of Chemistry.)

Figure 6.6 Molecular structures of the seven chiral amphiphiles and the corresponding morphologies and structures characterized by SEM and TEM images: (a) C

16

-l-Ala (313 K), (b) C

16

-l-Val (293 K), (c) C

16

-l-Ile (293 K), (d) C

16

-l-Met (293 K), (e) C

16

-l-Phe (293 K), (f) C

16

-l-Pro (323 K), (g) C

16

-d-Phe (293 K). (Qiu

et al

. 2008 [41]. Reproduced with permission of American Chemical Society.)

Figure 6.7 Illustration of the chirality produced from chiral molecules. (a) Chiral molecules tend to be packed at a nonzero angle between adjacent molecules. (Qiu

et al

. 2008 [41]. Reproduced with permission of American Chemical Society). (b) Molecular origin of the helical structures of the CMS originated from the helical propellerlike packing of the chiral amphiphilic molecules. (Shimizu

et al

. 2005 [42]. Reproduced with permission of American Chemical Society.)

Figure 6.8 (a

1

and a

2

) SEM and TEM images of the single-axis nanofiber. (b

1

and b

2

) SEM and TEM images of the dual-axis nanofiber. (Wang

et al

. 2006 [47]. Reproduced with permission of Wiley.)

Figure 6.9 (a) Simulation of the shape of the end of a rodlike sample and the corresponding TEM images (b). Integrating the equation of the curve in (a) gives the surface area of the end of the helical rods, which indicates the reduction in surface area. (c) Illustration of the formation of the helical mesostructured rods from hexagonally arrayed straight rodlike micelles. (Yang

et al

. 2006 [48]. Reproduced with permission of American Chemical Society.)

Figure 6.10 (a) Illustration of the effect of chiral additives on the formation of right- and left-handed chiral mesostructured TSPP–silica hybrid. SEM images (b), XRD pattern (c), and DRCD/UV–vis spectra (d) of the right-handed (up, blue line) and left- handed (down, red line) excess TSPP–silica hybrid. (Qiu

et al

. 2011 [57]. Reproduced with permission of Royal Society of Chemistry.)

Figure 6.11 Molecular structures of the nine achiral amphiphiles and the corresponding morphologies and structures characterized by SEM and TEM images: (a) C

14

-GlyNa, (b) C

16

-2-ALBA, (c) C

12

-SarNa, (d) C

12

-PO

4

Na

2

, (e) SDS, (f) C

14

Na, (g) CTAB, (h) C

18

MIMBr, and (i) C

16

-PyrBr. (Qiu and Che 2008 [58]. Reproduced with permission of American Chemical Society.)

Figure 6.12 Illustration of the asymmetric molecular shapes of the achiral amphiphiles. (Qiu and Che 2008 [58]. Reproduced with permission of American Chemical Society.)

Figure 6.13 (a) Temperature dependence of CMSs synthesized with different chiral

N

-acylamino acids. (b) Temperature dependence of the ln(

l/r

) value of CMSs with different chiral

N

-acylamino acids shows different slopes decreasing in order C

16

-l-Phe < C

16

-l-Met > C

16

-l-Ile > C

16

-l-Val > C

16

-l-Ala. (Qiu

et al

. 2008 [41]. Reproduced with permission of American Chemical Society.)

Figure 6.14 (a) Basicity dependence of the ee of the CMSs formed with C

16

-l-Phe at different temperatures. (b) Effect of basicity on the enantiopurity of the CMSs. (Adapted from Qiu and Che 2010 [64]. Reproduced with permission of The Chemical Society of Japan.)

Figure 6.15 Mechanical analysis of the helicity of CMS based upon the helical micellar packing of amphiphiles. (Qiu and Che 2008 [58]. Reproduced with permission of American Chemical Society.)

Figure 6.16 SEM (a) and TEM images (b) of the mesoporous materials synthesized using C

14

-l-AlaS as template at different temperatures 0 °C (a

1

and b

1

), 10 °C (a

2

and b

2

), 15 °C (a

3

and b

3

), 20 °C (a

4

and b

4

). (Jin

et al

. 2008 [74]. Reproduced with permission of Wiley.)

Figure 6.17 Synthesis-space diagram of C

16

-l-Ala template mesoporous silicas. The H

2

O/C

16

-l-Ala molar ratio and TEOS/C

16

-l-Ala molar ratio were kept at 1722 and 7, respectively. L: lamellar; I: bicontinuous ; P: 2D hexagonal

p

6

mm

; C: chiral mesophase. (Jin

et al

. 2008 [70]. Reproduced with permission of Elsevier.)

Figure 6.18 SEM (a), TEM (b), and structure schematic model (c) of the silica mesoporous crystal with 2D-rectangular

p

2

gg

mesostructure. (Qiu

et al

. 2008 [76]. Reproduced with permission of Wiley.)

Figure 6.19 Chiral nanotube with channels oriented parallel (a) and perpendicular (b) to the center axis of the nanotube. SEM images (a

1

and b

1

) and TEM images (a

2

and b

2

) of the samples. ((a

2

, b

1

, b

2

) Wu

et al

. 2007 [56]. Reproduced with permission of American Chemical Society; (a

1

) Yu

et al

. 2008 [77]. Reproduced with permission of Wiley.)

Figure 6.20 (A) Illustration of the helical arrangement of the quaternary ammonium groups on the silica wall of CMS guiding the of guest molecules, PPAS (a), TPPS (b) and DNA (c). (B) DRCD and UV/Vis spectra of PPAS (B

1

) and TPPS (B

2

) loaded in the extracted L-CMS (blue line) and R-CMS (red line). (Qiu

et al

. 2009 [79]. Reproduced with permission of Wiley.)

Figure 6.21 Schematic illustration, TEM images, and the corresponding DRCD/UV–vis spectra of Ag nanoparticles loaded in as-made CMS (a), postgrafted calcined CMS (b), and extracted CMS (c). (Xie

et al

. 2012 [84]. Reproduced with permission of Wiley.)

Figure 6.22 (A) Schematic illustration of the hierarchical chiral structure with in CMS. (B and C) TEM images and the DRCD spectra of the Ag nanowire loaded L- (dark line) and R-CMS (gray line). (Xie and Che 2012 [87]. Reproduced with permission of Wiley.)

Figure 6.23 Chiral gelator molecules (a

1

, b

1

, c

1

) and the corresponding morphology of the resulting helical TiO

2

fibers and nanotubes (a

2

, b

2

, c

2

and c

3

). ((a

2

) Jung

et al

. 2002 [90]. Reproduced with permission of American Chemical Society. (b

2

) Kobayashi

et al

. 2002 [91]. Reproduced with permission of American Chemical Society. (c

2

and c

3

) Zhang

et al

. 2012 [92]. Reproduced with permission of American Chemical Society.)

Figure 6.24 Formation mechanism, morphologies, structures, and the corresponding ETOAs of the as-made and calcined TiO

2

helical fibers. (a) Schematic drawing shows that the formation of the right-handed lipid–TiO

2

hybrid through the coordination interaction between titanium and carboxylic acid of the lamellar structured C

18

-d-Glu helical fibers. (b) SEM and TEM images of the right-handed as-made lipid–TiO

2

helical fiber. (c) TEM and the corresponding structural model of the right-handed calcined chiral crystalline TiO

2

. (d) DRCD/UV–vis spectra of the antipodal as-prepared and calcined chiral TiO

2

fibers. (Liu

et al

. 2012 [97]. Reproduced with permission of Nature Publishing Group.)

Figure 6.25 Illustration of the multiple liquid-crystals formed by stiff rodlike helix, from blue phase, cholesteric phase, to 2D hexagonal phase, to 3D hexagonal phase and 3D orthorhombic phase. (Liu

et al

. 2015 [105]. Reproduced with permission of Wiley.)

Figure 6.26 Illustration of DNA transcription into DNA–silica fibers based on the costructure directing route. Here, the TMAPS is chosen as the costructure directing agent and TEOS as silica source. (Jin

et al

. 2009 [110]. Reproduced with permission of Royal Society of Chemistry.)

Figure 6.27 Morphology and structure of the multihelical DNA–silica fibers (a) and the multihelical DNA–silica arrays (b) characterized by SEM (a

1

, a

2

, b

1

, b

2

) and TEM images (a

3

, b

3

). (Cao

et al

. 2012 [113]. Reproduced with permission of Royal Society of Chemistry.)

Figure 6.28 SEM images (a) and DRCD and UV/Vis spectra (b) of the antipodal impellerlike HDSA with left-handedness (25 °C) and right-handedness (0 °C). (Liu

et al

. 2011 [119]. Reproduced with permission of Wiley.)

Figure 6.29 Schematic illustration of the right-to-left handedness reversion at 25 °C along with the reaction proceeding. (Liu

et al

. 2013 [127]. Reproduced with permission of Royal Society of Chemistry.)

Figure 6.30 (a) Schematic illustration of the hierarchical chirality seen from different view directions. (b) The induced water-dependent plasmonic CD signals of silver nanoparticles incorporated in the HDSA. (Liu

et al

. 2013 [128]. Reproduced with permission of Wiley.)

Figure 6.31 Morphology and diverse OAs of CDSF. (a

1

, a

2

) Low- and high-magnification SEM images of the CDSF. (b) DRCD/UV–vis spectra of the as-made CDSF (red line), the calcined CDSF (blue line), and after immersed in water (dotted line). (Liu

et al

., 2014 [134] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4007082/. Used under CC BY 3.0 Unported License https://creativecommons.org/licenses/by/3.0/.)

Figure 6.32 Structural formula (a), simplified ball-stick model (b), and geometries in packing behavior (c) of the two peptides showing the effect of proline in the final

g

parameter of peptide. (Huang

et al

. 2014 [147]. Reproduced with permission of Wiley.)

Figure 6.33 Schematic illustration of the formation of different chiral structures with the variation of

g

value. (a) The β-sheet conformations forming through the intermolecular hydrogen bonds. (b

1

–b

4

)

g

value increasing along with the decreasing of hydrophilicity. (c

1

–c

4

) Structure transfer with different

g

values. (d

1

–d

4

) TEM images of the resulting mesostructured peptide–silica composition with decreasing

g

values of 1–4 . (Huang

et al

. 2014 [148]. Reproduced with permission of Wiley.)

Figure 6.34 (a) Structure formula of polypeptide. (b) Morphology of the screwed plates characterized by SEM image. (Bellomo and Deming 2006 [155]. Reproduced with permission of American Chemical Society.)

Figure 6.35 Structure formula of cellulose (a) and chitin (b).

Figure 6.36 (a) Illustration model of the Bouligand structure, the left picture illustrates the arcs from oblique cut sections. (Lenau and Barfoed 2008 [170]. Reproduced with permission of Wiley.). (b) TEM images of the typical Bouligand structures in the fruit shell of

Pollia condensata

. (c) Photography of the

P

.

condensata

shell showing the metallic blue color. ((b, c) Reproduced with permission of Vignolini

et al

. 2012 [170].)

Figure 6.37 Structure, OA, and the corresponding appearance of the colored freestanding cellulose–silica film. (a) Low- and (b) high-magnification SEM images showing the typical layered chiral nematic structure. (c) Transmission spectra of the calcined silica film. (d) Photography of the films with different reflective peaks shown in (c). (e) CD spectra of a green chiral film before (green line) and after (black line) immersed in water. (Shopsowitz

et al

. 2010 [179]. Reproduced with permission of American Chemical Society.)

Chapter 7: DNA-Based Chiral Nanostructures

Figure 7.1 The electrophoresis results of the nanoparticle–DNA conjugates. Lane 1: 10 nm Au NPs; Lane 2–3: 10 nm Au NPs–ssDNA; Lane 4: 10 nm Ag NPs; Lane 5: 10 nm Ag NPs–DNA; Lane 6: 5 nm QDs; Lane 7: 5 nm QDs–DNA.

Figure 7.2 A schematic illustration of scaled-up self-assembly of heterogeneous Au NPs through interface PCR. (a) Asymmetric PCR; (b) symmetric PCR [24].

Figure 7.3 Schematics for PCR-based Au nanorod assemblies [28]. (a) The replication procedure for PCR in which a DNA strand can be amplified under primer, template DNA, taq plus polymerase, and four different bases. (b) PCR-based gold NRs end-to-end (ETE) assembly. (c) PCR-based Au NRs side-by-side (SBS) assembly.

Figure 7.4 (A) Illustration of the DNA-programmed synthesis of heterodimer assemblies and chiral core–shell NPs with Ag shell grown on the DNA template. (B) CD and UV–vis absorption of growth of chiral core–shell NPs with varying shell thickness by adding into various volume of AgNO

3

. (C) Representative HRTEM images of chiral core–shell NPs (a, b), and achiral [email protected] NPs (c, d) [29].

Figure 7.5 (a) Schematics of chiral NP superstructures. (B) Circular dichroism spectra of products of PCR for increasing number of cycles. (c) Typical nanoparticle assemblies of different PCR cycles [23].

Figure 7.6 (a) Schematic illustration of PCR-assembled [email protected] core–shell (CS) NPs and [email protected] CS NPs with different shell thicknesses [35]. (b) Sequential postassembly deposition of Ag and Au shell [36].

Figure 7.7 Chiral sensor based on C–Ag

+

–C recognition between 10 nm Au NPs and 25 nm Au NPs [38].

Figure 7.8 Tomography 3D reconstruction of heterochains with different lengths. (a–c): 5 cycles, (d, e): 10 cycles, (f–h): 20 cycles [42].

Figure 7.9 CD spectra of heterochains from 2 to 5 cycles (a), from 5 to 20 cycles (b), and from 20 to 40 cycles (c). (d) Control group (0 cycles): mixtures of Au 25 NPs-F 50-PEG and Au 10 NPs-R 50-PEG in PCR buffer solution without PCR [42].

Figure 7.10 PCR-based Au nanorod ladder assemblies and chiroptical simulations [28]. Representative TEM images for SBS assemblies after 0 (a), 2 (b, c), 5 (d), 10 (e), and 15 (f) PCR cycles. Tomography images for NR trimer (g) and pentamer (h). UV–vis (i) and CD spectra (j) for SBS assemblies for 0–30 PCR cycles. (k) The wavelength λ

p

, λ

n

and λ

L

for SBS assemblies in CD and UV–vis spectra for different number of PCR cycles,

n

. (l) The maximum of anisotropy factor

g

max

plots for different cycles,

n

. Calculations of absorption (m) and CD spectra (n) for NRs SBS structures. The number of NRs

n

was set from 1 to 5 NRs.

Figure 7.11 (A) Examples of chiral pyramids [45]. (B) Circular dichroism spectra of self-assembled pyramids made from (a) four Au

1

(type 1) and three Au

2

+ Au

3

(type 2); (b) two Au

2

+ two QDs (type 3), and Au

2

+ Au

3

+ two QDs (type 4) [inset: CD spectrum in 300–450 nm region]; and (c) Au

2

+ Au

3

+ Ag + QD as

S

- (type 5) and

R

-enantiomers (type 6) [12].

Figure 7.12 Schematic representation of the detection of DNA-based frame changes of pyramids. (a) “off”–“on” mode; (b) “on”–“off” mode [46].

Figure 7.13 (a, b) Representative TEM images for Py1 and Py2. The inset corresponds to 3D tomographic reconstruction images of Py1 and Py2. (c, d) Synchrotron small-angle X-ray scattering (S-SAXS) and dynamic light scattering size distributions of Py1 and Py2. (e, f) CD and UV–vis spectra of Py1 and Py2 and statistical analysis of the number of Au NPs assemblies in these two systems [46].

Figure 7.14 (a, b) Representative TEM images for Py3 and Tr3. The inset corresponds to the schematic structures of Py3 and Tr3. (c) Agarose gel image and TEM images of Py3 and its products at different experimental stages. The direction of migration is top to bottom. (1–2) 10 and 20 nm Au NPs; (3) heterodimers of Au NPs; (4, 5) 10 and 20 nm Ag NPs; (6) heterodimers of Ag NPs; (7) Py3 formed by mixing heterodimers of Au NPs and Ag NPs; (8) heterotrimers of Tr3. The scale bars are 10 nm. (d, e) Absorption spectra of Py3and Tr3 and statistical analysis of the number of Au NPs assemblies in these two systems [46].

Figure 7.15 (a) Scheme of Ag pyramids self-assembled by DNA frame for multiple analyses of disease biomarkers [48]. (b) Fabrication of Ag NP ornamented–Au NP pyramids and sensing applications [49].

Figure 7.16 (a) Left- and right-handed nanohelices (diameter 34 nm, helical pitch 57 nm) of DNA origami gold nanoparticle helices and principle of circular dichroism [51]. (b) Surface-bound left-handed helix [2].

Figure 7.17 Schematic illustration of the assembly and disassembly of

core–satellites

Au NR–Au NPs superstructures [53].

Figure 7.18 TEM images and optical properties of NP heterodimers [58]. (a, b) The typical TEM images of heterodimers assembled by DNA (a) and NaCl (b); (c, d) The UV–vis and CD spectra of NPs heterodimers triggered by DNA (c) and NaCl (d); (e, f) The calculated spectra of NPs heterodimers triggered by DNA (e) and NaCl (f).

Figure 7.19 Optical properties of NP dimers with different interparticle distances [58]. Typical high-resolution TEM images (a–c), CD and UV/vis spectra (d) and DLS diameter (e) of three kinds of heterodimers with various interparticle distances (3.4 nm (a), 8.8 nm (b), and 14.3 nm (c)).

Figure 7.20 Structural characteristics and optical properties of NPs dimers assembled with different sizes of NPs [58]. (a–d) TEM images of NPs dimers of Au

1

-Au

1

, Au

1

-Au

2

, Au

1

-Au

3

and Au

2

-Au

2

. (e) CD and UV–vis spectra of NPs dimers of Au

1

-Au

1

, Au

1

-Au

2

, Au

1

-Au

3

and Au

2

-Au

2

. Absorbance of Au

1

dimer (black line), Au

1

-Au

2

dimer (reseda line), Au

1

-Au

3

dimer (red line), Au

2

-Au

2

dimer (blue line); CD of Au

1

dimer (black line); Au

1

-Au

2

dimer (reseda line), Au

1

-Au

3

dimer (red line), Au

2

-Au

2

dimer (blue line). (f) The kinetic profile of DNA induced NPs dimers. The wavelength shift of CD (λ

c

) and UV–vis (λ

a

) and the intensity of CD (

I

c

) and UV–vis (

I

a

) changes for four kinds of dimers.

Figure 7.21 Chiroptical characteristics and geometries for heterodimer and homodimer [33]. Experimental (a, c) and theoretical (b, d) spectra of CD (a, b) and UV–vis absorption (c, d) for heterodimers (13 nm of Ag NPs and 28 nm of Au NPs, red line) and monodispersed naked NPs (13 nm of Ag NPs, black line and 28 nm of Au NPs, gray line). (e, f) Spectra of CD (e) and UV–vis absorption (f) for Ag NPs–Au NPs heterodimers (13 nm of Ag NPs and 28 nm of Au NPs, red line), Ag NPs homodimers (13 nm, black line), Ag NPs homodimers (20 nm, blue line), Au NPs homodimers (13 nm, pink line), and Au NPs homodimers (28 nm, green line). (g) Representative TEM images of the assembled heterodimers. (h) Zoomed-in TEM image of a heterodimer. (i) The scissor-like geometry of NP dimer in solution with dihedral angles between the long axes of NPs marked. (j–m) TEM tomography images of assembled heterodimers. The two constitutive NPs are not parallel to each other, but have a dihedral angle, between the long NP axes marked with dashed lines and dot lines.

Figure 7.22 Structural characteristics of nanorod assemblies [37]. (a) Schematics of gold NRs dimers made with SCA, SCI, and DNA. (b) Yields of NR dimers for SCA (black), SCI (red), and DNA (blue) assemblies, respectively, under optimized conditions and reaction times. TEM images for dimers made by SCA (c), SCI (d), and DNA (e), respectively. SEM images for NR dimers made by SCA (f), SCI (g), and DNA (h), respectively. 3D TEM tomography images for front view (i), back view (j), and tilted view (k) of NR dimers assembled with SCA. Schematics of (−) enantiomer (l) and (+) enantiomers (m). Geometrical parameters

d

,

s

, denote twist angle between NRs (in degrees), intrananorod gap (in nanometers), and vertical offset of NRs with respect to each other (in nanometers), respectively.

Figure 7.23 Optical properties of a single NR dimer obtained by single particle spectroscopy [37]. (a) TEM images different magnifications of the specific single twisted dimer used in optical measurements taken from the TEM grid. (b) Dark-field scattering image of single dimer in (a). The optical properties of a single dimer for (c) dark-field scattering spectrum and (d) circular dichroism spectrum.

Figure 7.24 Schematics of dimer and trimer for (−)-enantiomer and (+)-enantiomer [28]. The depicted geometry was used in the computer calculation, with angles −9.0°, −7.1°, −8.0°, −7.0°, respectively, according to TEM tomography.

Figure 7.25 (A) Simulations of

E

-field of chiral NR trimer and pentamer. (a–c)

E

-field of chiral NR trimer. (d–f)

E

-field of chiral NR pentamer. (B) The excitation beam was set under LCP and RCP excitation for a specific incident direction,

z

= 0° and φ

x

= 90° [28].

Chapter 8: Applications in Catalysis

Scheme 8.1 Homogeneous catalysts versus immobilized catalysts.

Scheme 8.2 Examples of metal nanoparticle catalysis.

Scheme 8.3 Asymmetric hydrogenation of imines catalyzed by Pd on silk fibroin fiber.

Scheme 8.4 Asymmetric hydrogenation of carbonyl compounds catalyzed by tartaric-acid-modified Raney Ni.

Scheme 8.5 Orito reactions.

Scheme 8.6 Asymmetric hydrogenation of α-ketoesters catalyzed by Pt/CNTs.

Scheme 8.7 Representative examples of good chiral modifiers for a wide variety of substrates.

Scheme 8.8 Proposed reaction mechanism for the Orito reaction.

Scheme 8.9 Asymmetric hydrogenation of diarylpropenoic acids over cinchonidine-modified Pd catalyst.

Scheme 8.10 Asymmetric hydrogenation of diarylpropenoic acids over cinchonidine-modified Pd/Al

2

O

3

.

Scheme 8.11 Asymmetric hydrogenation of olefins over cinchonidine-modified Pd catalyst.

Scheme 8.12 Asymmetric hydrogenation of isophorone catalyzed by DHVIN-modified Pd.

Scheme 8.13 Asymmetric hydrogenation of isophorone catalyzed by Pd and proline, and initially proposed mechanism.

Scheme 8.14 Revised reaction mechanism.

Scheme 8.15 Preparation of nickel boride nanoparticles.

Scheme 8.16 Asymmetric reduction of ketones catalyzed by BH

3

Ni-oxazaborolidine.

Scheme 8.17 Asymmetric hydrogenation of aromatic ketones catalyzed by chiral Ru nanoparticles.

Scheme 8.18 Asymmetric hydrogenation of aromatic ketones catalyzed by chiral Ir nanoparticles.

Scheme 8.19 Asymmetric hydrogenation of unsaturated ketone catalyzed by chiral Ir nanoparticles.

Scheme 8.20 Asymmetric hydrogenation of heteroaromatic methyl ketones catalyzed by chiral Ir nanoparticles.

Scheme 8.21 Asymmetric hydrogenation of aromatic ketones catalyzed by chiral Ru nanoparticles.

Scheme 8.22 Asymmetric transfer hydrogenation of ketones catalyzed by chiral Fe nanoparticles.

Scheme 8.23 Proposed active species in Fe-catalyzed asymmetric transfer hydrogenation.

Scheme 8.24 Asymmetric hydrosilylation of styrene, catalyzed by BINAP–Pd nanoparticles.

Scheme 8.25 Asymmetric hydrosilylation of aromatic ketones catalyzed by nano-CuO with BINAP.

Scheme 8.26 Asymmetric hydrosilylation of ketones catalyzed by CuFe

2

O

4

with BINAP.

Scheme 8.27 Asymmetric hydrosilylation of aromatic ketones catalyzed by CuFe

2

O

4

@KIT-6 with Xyl-P-Phos.

Figure 8.1 Microencapsulation technique.

Scheme 8.28 MC Pd-catalyzed asymmetric allylation.

Schemes 8.29 Synthesis of chiral Pd nanoparticles.

Figure 8.30 Chiral diphosphite ligands.

Scheme 8.31 Asymmetric allylic alkylation of

rac

-

13

with dimethyl malonate by Pd catalyst.

Scheme 8.32 Asymmetric Suzuki–Miyaura coupling reactions catalyzed by chiral Pd nanoparticles.

Scheme 8.33 Preparation of Fe

3

O

4

/Pd nanoparticles modified by chiral NHC

16

.

Scheme 8.34 Asymmetric α-arylation of ketones with aryl halides.

Scheme 8.35 Preparation of a molecular catalyst and a Pd nanoparticle catalyst on Fe

3

O

4

.

Scheme 8.36 Asymmetric allylation of 4-nitrobenzaldehyde with allyltributyltin.

Scheme 8.37 Chiral diphosphine ligands.

Scheme 8.38 Asymmetric hydroformylation of olefins by BINAP-Rh/SiO

2

.

Scheme 8.39 Synthesis of chiral Rh nanoparticles

9

and

22

.

Scheme 8.40 Asymmetric hydroformylation of styrene catalyzed by Rh nanoparticles.

Scheme 8.41 Asymmetric Pauson–Khand-type reactions catalyzed by Co/Rh nanoparticles.

Scheme 8.42 Asymmetric 1,4-addition reaction catalyzed by Rh/Ag nanoparticles.

Scheme 8.43 Asymmetric Henry reactions catalyzed by NAP–MgO.

Scheme 8.44 Asymmetric Michael reactions with nitroalkanes catalyzed by NAP–MgO.

Scheme 8.45 Asymmetric aldol reactions catalyzed by NAP–MgO.

Scheme 8.46 Asymmetric Michael reactions with malonates catalyzed by NAP–MgO.

Scheme 8.47 Asymmetric aldol reactions catalyzed by nano-CuO.

Figure 8.2 Au nanoparticles encapsulated in a chiral SAM/mesoporous MCF-17 support.

Scheme 8.48 Asymmetric intermolecular cyclopropanation catalyzed by [email protected]/MCF-17.

Scheme 8.49 Asymmetric intramolecular cyclopropanation catalyzed by [email protected]/MCF-17.

Chapter 9: Applications in Polymer Science

Figure 9.1 Molecular structures of the bissilsesquioxanes.

Figure 9.2 Molecular structures of the LMWAs.

Figure 9.3 Molecular structures of the bissilsesquioxanes.

Figure 9.4 FESEM (a–c) and TEM (d) images of left-handed multiple helical mesoporous 1,4-phenylene-silica nanofibers; FESEM image (e) of right-handed multiple helical mesoporous 1,4-phenylene-silica nanofibers. (Wu

et al

. 2009 [39]. Reproduced with permission of American Chemical Society.)

Figure 9.5 (a) FESEM and (c) TEM images of the left-handed helical 1,4-phenylene-bridged polybissilsesquioxane nanotubes prepared using

LL-5

; (b) FESEM and (d) TEM images of the right-handed helical 1,4-phenylene-bridged polybissilsesquioxane nanotubes prepared using

DD-5

[40].

Figure 9.6 FESEM (a and c) and TEM (b and d) images of 4,4′-biphenylene-silicas. (a and b)

S1

; (c and d)

S2

. (Li

et al

. 2011 [43]. Reproduced with permission of Royal Society of Chemistry.)

Figure 9.7 FESEM (a) and TEM (b) images of the helical 1,4-phenylene-bridged polybissilsesquioxane nanorods prepared using

L-9

; FESEM (c) and TEM (d) images of the nanorods prepared using

D-9

. (Liu

et al

. 2011 [44]. Reproduced with permission of Royal Society of Chemistry.)

Figure 9.8 TEM images of the reaction mixture after different reaction times: (a) 0 s; (b) 90 s; (c) 3.0 min, and (d) 4.0 min. (Chen

et al

. 2008 [46]. Reproduced with permission of Royal Society of Chemistry.)

Figure 9.9 FESEM (a–c) and TEM (d) images of left-handed helical 4,4′-biphenylene-bridged polybissilsesquioxane nanotubes prepared from

D-11

using a water/ethanol volume ratio of 2.2 : 1.8; FESEM (e and f) and TEM (g and h) images of right-handed helical 4,4′-biphenylene-bridged polybissilsesquioxane nanotubes prepared from

L-11

using a water/ethanol volume ratio of 2.2 : 1.8. (Wang

et al

. 2010 [50]. Reproduced with permission of Elsevier.)

Figure 9.10 Schematic illustration of the formation of single-handed helical polybissilsesquioxane nanostructures.

Figure 9.11 Simulated nanorings with different twist angles. (Zhu

et al

. 2012 [62]. Reproduced with permission of Wiley.)

Figure 9.12 Simulated CD spectra, simulated at the B3LYP/6-311++G** level and right-handed stacking of phenylene rings.

Figure 9.13 Optimized structures for compounds:

BTSB

,

2-2

,

2-3a

,

2-3b

, and

3-3

. L: left-handed; R: right-handed. (C: gray; H: white; Si: purple; O: red.) (Li

et al.

2011 [43]. Reproduced with permission of Royal Society of Chemistry.)

Figure 9.14 Simulated CD spectra for compounds

BTSB

,

2-2

,

2-3a

,

2-3b

and

3-3

. (Li

et al.

2011 [43]. Reproduced with permission of Royal Society of Chemistry.)

Figure 9.15 Preparation of single-handed helical inorganic nanotubes using polysilsesquioxanes as starting materials.

List of Tables

Chapter 2: Chirality at Nanoscale – Theory and Mechanism

Table 2.1 Comparison between the experimental (Exp.) and theoretical (Theor.) results of anisotropic factors (

g

EE

and

g

SS

) of CD peaks corresponding to LSPR of EE and SS assembled GNRs with different aspect ratios

Table 2.2 Comparison between the experimental (Exp.) and theoretical (Theor.) results of anisotropic factors (

g

EE

and

g

SS

) of CD peaks corresponding to TSPR of end-to-end (EE) and side-by-side (SS) assembled GNRs with different aspect ratios

Table 2.3 Comparison between the theoretical and experimental results of the CD response with changing the aspect ratio of Au NRs

Table 2.4 Comparison between the theoretical and experimental results of the CD response with changing the size of the chiral QDs

Chapter 5: Chirality in Gold Nanoclusters

Table 5.1 Summary of the point groups of Au

n

(SR)

m

nanoclusters

Chapter 7: DNA-Based Chiral Nanostructures

Table 7.1 Comparison of

g

factor among different chiral dimers

Chapter 8: Applications in Catalysis

Table 8.1 Relationship of the catalyst shape, ee, and TOF in the asymmetric hydrogenation of ethyl pyruvate.

Table 8.2 Asymmetric allylic alkylation of

rac

-

13

with dimethyl malonate catalyzed by Pd

Chiral Nanomaterials

Preparation, Properties and Applications

Editor

Prof. Zhiyong Tang

National Center for Nanoscience and Technique

No. 11 Beiyitiao

Zhongguancun

Haidian District

100190 Beijing

China

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Chapter 1An Introduction to Chiral Nanomaterials: Origin, Construction, and Optical Application

Zhengtao Li, Lin Shi and Zhiyong Tang

The National Center for Nanoscience & Technology, No. 11 Beiyitiao, Zhongguancun, Beijing, 100190, China

1.1 Introduction