Optical Activity and Chiral Memory of Thiol-Capped CdTe Nanocrystals

Nakashima, Takuya; Kobayashi, Yuki; Kawai, Tsuyoshi

doi:10.1021/ja902800f

Cited by 201 publications

(223 citation statements)

References 30 publications

Supporting

Mentioning

206

Contrasting

Unclassified

Order By: Relevance

“…10 More recent reports on chiral CdTe based nanoparticles have also been published. 11,12 There is also a very recent theoretical work, which demonstrated that the electric field of the metal or semiconductor nanoparticle enhances the signal from the chiral stabiliser and other chiral species.13 Chirality is a common occurrence in the natural world and chiral compounds have very important applications in chemistry, biology, pharmacology and medicine. Therefore chiral nanoparticles have been envisaged to play an important role in science and technology.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Chiral luminescent CdS nano-tetrapods

et al. 2010

View full text Add to dashboard Cite

The utilisation of chiral penicillamine stabilisers allowed the preparation of new water soluble white emitting CdS nano-tetrapods, which demonstrated circular dichroism in the band-edge region of the spectrum.Semiconductor nanocrystals or quantum dots are remarkable for their size dependent optical and photonic properties, which differ significantly from the bulk material. These unique properties are of great interest for a number of potential applications including biomedical imaging, 1-4 sensing, 5 light-emitting diodes (LEDs), 6 photovoltaics 7 and displays. 8Previously the preparation of new chiral quantum dots which demonstrate circular dichroism (CD) activity was achieved by the microwave synthesis in the presence of the chiral penicillamine stabiliser. 9 In this case the formation of chiral defects in the nanocrystals structure leads both to the defect emission and CD response. 10 More recent reports on chiral CdTe based nanoparticles have also been published. 11,12 There is also a very recent theoretical work, which demonstrated that the electric field of the metal or semiconductor nanoparticle enhances the signal from the chiral stabiliser and other chiral species.13 Chirality is a common occurrence in the natural world and chiral compounds have very important applications in chemistry, biology, pharmacology and medicine. Therefore chiral nanoparticles have been envisaged to play an important role in science and technology. 14,15 In particular CD active luminescent nanoparticles have a great potential for the development of new chiral nanosensors.Over last years there have also been several reports on semiconductor nanomaterials with tetrapodal morphology. These amazing nanostructures have been of great interest due to their potential use in photovoltaics, 16 in the synthesis of asymmetric nano-assemblies 17 as well as prospective additives for polymer reinforcement.18 These materials have also displayed anisotropic emission 19 as a direct result of their morphology. Normally the synthesis of nanotetrapods 18,[20][21][22][23][24][25][26][27][28][29] involves the use of high temperature organic phase reactions or the utilisation of solvothermal approach. The mechanism proposed for the formation of these structures 23 engages the generation of seed nanocrystals that subsequently act as sites for preferential growth of the arms. Evidence for this mechanism may be found in the production of heterostructures using prepared pre-formed seed of one material followed by the use of additional materials to grow the arms. 28,30Here we report new chiral CdS nanotetrapods, which have been produced by heating of a basic aqueous solution of CdCl 2 , thioacetamide and racemic (Rac), D-or L-enantiomeric forms of penicillamine (Pen) under reflux.z Samples of the products have been diluted and examined using UV-VIS and photoluminescence (PL) spectroscopy to analyse the absorbance and emission characteristics of the samples. The absorbance spectra show a defined band edge at approximately 370 nm for both enantiomers of the...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Chiral luminescent CdS nano-tetrapods

et al. 2010

View full text Add to dashboard Cite

show abstract

“…The red shift of previous silicon with styrene might be due to specific interaction between silicon surface and aromatic ring of the styrene units [21]. We have reported that the emission quantum yield of silicon nanoparticles with styrene molecules (emission wavelength = 680 nm) was found to be 55 %.…”

Section: Emission Properties Of Silicon Nanoparticles With Chiral Molmentioning

confidence: 94%

“…In particular, lanthanide complexes with chiral molecules show large CPL signals, which are expected to be useful in future chiroptical applications such as three dimensional display and chiroptical memory [20]. Chiroptical memory and sensor using CdTe, and CdSe/ZnO nanoparticles rapped with chiral molecules have been suggested [21][22]. Recently, induced CD and CPL properties in CdSe quantum dots have been reported [23].…”

Section: Introductionmentioning

confidence: 99%

Luminescent Silicon Nanoparticles Surface-Modified with Chiral Molecules

Miyano

Nakanishi

Wada

et al. 2015

J. Photopol. Sci. Technol.

View full text Add to dashboard Cite

Active surface of luminescent silicon nanoparticles was terminated by the photochemical reaction of chiral molecules, (S)-or (R)-5-allyl-2-oxabicyclo[3,3,0]oct-8-ene ((S) -or (R) -AOBE) under UV light. The particle size and shapes were characterized using Transmission Electron Microscope (TEM). The average particle size was found to be 5.7 nm. Circular dichroism (CD) signals with large dissymmetry factors from silicon nanoparticles terminated with (S) -and (R) -AOBE were observed at around 300 nm and 500 nm, which were much larger than those of (S)-and (R)-AOBE molecules. The silicon nanoparticles covered with (S)-or (R)-AOBE provided red luminescence based on the indirect electronic transition. Effective circular polarized luminescence (CPL) was not observed from indirect transition band.

show abstract

“…The NPs prepared via the hot-soap method were firstly dispersed in chloroform, which were subjected to the ligand-exchange with TCB by a simultaneous phase transfer method to give aqueous dispersions. 21 1-Butylimidazolium Tf 2 N (bmimTf 2 N) was chosen as a representative IL. All NPs were dispersed in bmimTf 2 N by a simple liquidliquid extraction technique from aqueous dispersions of equivolume.…”

mentioning

confidence: 99%

A Versatile Surface Design to Disperse Nanoparticles in Ionic Liquids and Organic Solvents

Taniguchi¹,

Yasue²,

Kawai³

et al. 2016

Chemistry Letters

Self Cite

View full text Add to dashboard Cite

Thiocholine bromide was proposed as a cationic capping ligand for a variety of metal and semiconductor nanoparticles with a good dispersibility in an ionic liquid (IL). The stability of NPs was improved in the IL compared to that in water, which was verified by an improved emission property of semiconductor nanoparticles and higher thermal stability of gold nanoparticles. The cationic thiocholine was further demonstrated as a surface ligand for CdTe nanoparticle dispersible in organic media in combination with various anions. Ionic liquids (ILs) have received considerable interest for the last two decades as a novel class of liquid materials because of unique properties that are tunable through a vast range of combinations of ionic components.1,2 Some of the recent studies have been directed to materials chemistry. 36 The combinations of ILs with nanoparticles (NPs) are of particular interest from the viewpoint of various practical applications, for which performances partly emerge by the synergetic interaction between the function inherent to NPs and the self-organizing property of ILs.7,8 A wide range of NPs including metallic, metal oxide, and semiconductor NPs, with or without surface-capping ligands, were stably dispersed in ILs. 79 Since the dispersion of NPs based on the electrical double layer repulsion cannot be expected in such ionic media, 10 IL-based solvation is most likely responsible for the colloidal stability of NPs in ILs. 79Surface-capping ligands of NPs not only passivate the active inorganic surface but also mediate interactions between the NPs and surrounding media as a buffer layer. In this context, NPs stabilized with imidazolium-functionalized ligands showed good stability in ILs. 1113 Even the electrostatic repulsion between the NPs is considered to be ineffective in ILs. 7 The formation of a double layer on the charged surface 14 in ILs might sufficiently protect NPs from agglomeration.7 Recent force measurement and neutron scattering studies proposed that ionic components of ILs form a solvation layering structure up to 5 nm in a layer-by-layer manner. 1517 We have reported that luminescent CdTe 18 and Au NPs 19 were stably dispersed in ILs with bis(trifluoromethanesulfonyl)amide (Tf 2 N) anion. These NPs were capped with cationic thiols such as 2-(dimethylamino)ethanethiol hydrochloride (DMAET) and thiocholine bromide (TCB). The use of Tf 2 N anion as a counter ion of these cationic thiols enabled the NP-dispersion over 40 wt % of gold content. 19 In the present work, the versatility of cationic thiocholine (TC) as a capping ligand of NPs is demonstrated in two ways. Firstly, we expand the range of NPs stably dispersed in ILs including anisotropic-shaped NPs. Secondly, the TCcapped CdTe NPs as a representative thiol-capped NP are dispersed in polar media in combination with various counter anions.Metal and semiconductor NPs were prepared according to the reported methods (see Supporting Information (SI)). TCBcapped NPs including Au, 20 PbS, ZnSe, CdTe, 18 and CdSe NPs were direct...

show abstract

Optical Activity and Chiral Memory of Thiol-Capped CdTe Nanocrystals

Cited by 201 publications

References 30 publications

Chiral luminescent CdS nano-tetrapods

Chiral luminescent CdS nano-tetrapods

Luminescent Silicon Nanoparticles Surface-Modified with Chiral Molecules

A Versatile Surface Design to Disperse Nanoparticles in Ionic Liquids and Organic Solvents

Contact Info

Product

Resources

About