Synthesis of a New Class of Molecule Li+@C60O–(OH)7 as a “Cation-Encapsulated Anion Nanoparticle” by Multihydroxylation of Li-Encapsulated Fullerene

2013 ◽  
Vol 1505 ◽  
Author(s):  
Hiroshi Ueno ◽  
Yuji Nakamura ◽  
Naohiko Ikuma ◽  
Ken Kokubo ◽  
Takumi Oshima
Keyword(s):  
Fullerene Cage ◽  
Hydroxyl Groups ◽  
Polar Solvents ◽  
Marked Contrast ◽  
Endohedral Fullerenes ◽  
New Class ◽  
Research Fields ◽  
Major Isomer ◽  
Subsequent Hydrolysis ◽  
Site Selective

ABSTRACTTreatment of [Li+@C60](PF6–) with 30% fuming sulfuric acid and subsequent hydrolysis gave hydroxylated derivative Li+@C60O–(OH)7. Its structure was deduced by IR, NMR, MALDI-TOF/FAB MS, and elemental analysis. Notably, the reaction of [Li+@C60](PF6–) was site-selective, giving a single major isomer (ca. 70%) with two minor isomers, in marked contrast to the case of empty C60. Furthermore, the results clearly indicate that the internal Li cation was strongly shielded by the surface dipolar hydroxyl groups, and thus it appears that the properties of endohedral fullerenes can be controlled by the external modification of the fullerene cage. Whereas Li+@C60 is relatively insoluble, Li+@C60O–(OH)7 was found to be highly soluble in polar solvents such as DMSO and DMF. The increased solubility is especially desirable for biological/medicinal assays and applications in such research fields.

Light-Mediated Cross-Coupling of Anomeric Trifluoroborates

2021 ◽  
Author(s):  
Eric Miller ◽  
Maciej Walczak
Keyword(s):  
Cross Coupling ◽  
Hydroxyl Groups ◽  
Anomeric Effect ◽  
Computational Studies ◽  
Carbohydrate Chemistry ◽  
New Class ◽  
Free Hydroxyl ◽  
Anomeric Carbon ◽  
Stereoselective Reactions

Stereoselective reactions at the anomeric carbon constitute the cornerstone of preparative carbohydrate chemistry. Here, we report the synthesis of axial C1 trifluoroborates and stereoselective C-arylation and etherification reactions under photoredox conditions. These reactions are characterized by high anomeric selectivities for 2-deoxysugars and broad substrate scope (24 examples), including disaccharides and trifluoroborates with free hydroxyl groups. Computational studies show that high axial selectivities for these reactions originate from a combination of kinetic anomeric effect of the intermediate C1 radical and stereoelectronic stabilization of Ni(III) through the metallo-anomeric effect. Taken together, this new class of carbohydrate reagents adds the palette of anomeric nucleophile reagents suitable for efficient installation C-C and Cheteroatom bonds.

Light-Mediated Cross-Coupling of Anomeric Trifluoroborates

2021 ◽  
Author(s):  
Eric Miller ◽  
Maciej Walczak
Keyword(s):  
Cross Coupling ◽  
Hydroxyl Groups ◽  
Anomeric Effect ◽  
Computational Studies ◽  
Carbohydrate Chemistry ◽  
New Class ◽  
Free Hydroxyl ◽  
Anomeric Carbon ◽  
Stereoselective Reactions

Stereoselective reactions at the anomeric carbon constitute the cornerstone of preparative carbohydrate chemistry. Here, we report the synthesis of axial C1 trifluoroborates and stereoselective C-arylation and etherification reactions under photoredox conditions. These reactions are characterized by high anomeric selectivities for 2-deoxysugars and broad substrate scope (24 examples), including disaccharides and trifluoroborates with free hydroxyl groups. Computational studies show that high axial selectivities for these reactions originate from a combination of kinetic anomeric effect of the intermediate C1 radical and stereoelectronic stabilization of Ni(III) through the metallo-anomeric effect. Taken together, this new class of carbohydrate reagents adds the palette of anomeric nucleophile reagents suitable for efficient installation C-C and Cheteroatom bonds.

Crown-interlocked lanthanide diphthalocyaninates with switchable panchromatic absorption

2017 ◽  
Vol 21 (04-06) ◽  
pp. 406-415 ◽  
Author(s):  
Kirill P. Birin ◽  
Anna I. Poddubnaya ◽  
Elena V. Isanbaeva ◽  
Yulia G. Gorbunova ◽  
Aslan Yu. Tsivadze
Keyword(s):  
Mass Spectrometry ◽  
Polar Solvents ◽  
Maldi Tof Mass Spectrometry ◽  
New Class ◽  
Maldi Tof ◽  
Wide Range

New class of clamshell-type lanthanide (Ce(IV), La(III) and Eu(III)) diphthalocyaninates bearing 24-crown-8 linking fragment are synthesized and characterized by means of NMR, UV-vis spectroscopies and MALDI-TOF mass spectrometry. A strong solvatochromism of the complexes, allowing switching the wide-range panchromatic absorption in polar solvents, is demonstrated by means of UV-vis and NMR spectroscopies and attributed to solvent-induced changing of sandwich conformations. The photodegradation of the obtained complexes was also investigated.

Site-Selective Functionalization of Hydroxyl Groups in Carbohydrate Derivatives

2018 ◽  
Vol 118 (23) ◽  
pp. 11457-11517 ◽  
Author(s):  
Victoria Dimakos ◽  
Mark S. Taylor
Keyword(s):  
Hydroxyl Groups ◽  
Selective Functionalization ◽  
Site Selective

scholarly journals Ion Pairs of 1-Butyl-3-Methylimidazolium Triflate Do Not Dissociate in Propan-1-ol: A Vibrational Spectroscopic Viewpoint

2020 ◽  
Vol 10 (5) ◽  
pp. 1620
Author(s):  
Johannes Kiefer ◽  
Marcus Stuckenholz ◽  
Claudia Caroline Rullich ◽  
Bernd Rathke
Keyword(s):  
Principal Component Analysis ◽  
Ionic Liquid ◽  
Spectral Decomposition ◽  
Ion Pairs ◽  
Principal Component ◽  
Hydroxyl Groups ◽  
Infrared Absorption Spectroscopy ◽  
High Dilution ◽  
Polar Solvents ◽  
Imidazolium Ionic Liquids

Adding imidazolium ionic liquids to polar solvents such as alkyl alcohols usually results in the dissociation of ion pairs as cation–anion interactions are replaced, e.g., by ion⋯OH hydrogen bonds. In this Communication, we apply Raman scattering and infrared absorption spectroscopy to an example binary system comprising 1-butyl-3-methylimidazolium trifluoromethanesulfonate (triflate) and propan-1-ol. The spectra are analyzed using principal component analysis (PCA), excess spectroscopy, and spectral decomposition. The results provide evidence that the ion pairs of the ionic liquid do not dissociate in propan-1-ol, even at high dilution. Moreover, there are clear signs that the propan-1-ol hydrogen bonding network is disrupted in the presence of the ionic liquid as the hydroxyl groups predominantly interact with the sulfonate oxygen atoms.

scholarly journals Surface Chemical Modification of Multiwalled Carbon Nanotubes by a Wet-Mechanochemical Reaction

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Lifei Chen ◽  
Huaqing Xie ◽  
Yang Li ◽  
Wei Yu
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Domain Size ◽  
Mechanochemical Reaction ◽  
Hydroxyl Groups ◽  
Polar Solvents ◽  
Multiwalled Carbon ◽  
Functionalized Surfaces ◽  
Alcohol Solvent ◽  
Surface Chemical Modification

A wet-mechanochemical reaction for surface modification of multiwalled carbon nanotubes (CNTs) has been developed. In the treatment, CNTs reacted with potassium hydroxide in alcohol solvent at room temperature under mechanical milling. The results from Fourier transmission infrared spectroscopy demonstrate that the nonreactive surfaces of CNTs have been modified successfully by multiple hydroxyl groups. Functionalized carbon nanotubes exhibit higher zeta potential values indicating their high dispersibility in polar solvents. XRD studies corroborate that the surface functionalization does not affect the basic crystal domain size of CNTs. TEM observations reveal that CNTs have been cut into shorter ones by the milling. Shortened CNTs with functionalized surfaces show good dispersion properties.

scholarly journals Device Applications of Synthetic Topological Insulator Nanostructures

Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 225 ◽  
Author(s):  
Chenxi Yue ◽  
Shuye Jiang ◽  
Hao Zhu ◽  
Lin Chen ◽  
Qingqing Sun ◽  
...  
Keyword(s):  
Topological Insulator ◽  
Condensed Matter ◽  
Electronic Devices ◽  
Surface States ◽  
Volume Ratio ◽  
Conducting Surface ◽  
New Class ◽  
Research Fields ◽  
Quantum Matter ◽  
Device Applications

This review briefly describes the development of synthetic topological insulator materials in the application of advanced electronic devices. As a new class of quantum matter, topological insulators with insulating bulk and conducting surface states have attracted attention in more and more research fields other than condensed matter physics due to their intrinsic physical properties, which provides an excellent basis for novel nanoelectronic, optoelectronic, and spintronic device applications. In comparison to the mechanically exfoliated samples, the newly emerging topological insulator nanostructures prepared with various synthetical approaches are more intriguing because the conduction contribution of the surface states can be significantly enhanced due to the larger surface-to-volume ratio, better manifesting the unique properties of the gapless surface states. So far, these synthetic topological insulator nanostructures have been implemented in different electrically accessible device platforms via electrical, magnetic and optical characterizations for material investigations and device applications, which will be introduced in this review.

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