Transient Crystal Structure of Oscillating Quartz

Piezoelectric quartz oscillators are widely used to provide a stable clock signal for watches and other electric circuits. The electrically induced mechanical vibration of quartz will be caused by ionic displacements of cationic Si and anionic O sublattices against each other. However, the transient and small ionic displacements during the mechanical vibration cannot be observed by usual X-ray structure analysis. The electrically induced mechanical vibration of quartz is resonantly amplified under an alternating electric field with the resonant frequency. We have revealed the amplified lattice strain and ionic displacements in a resonantly vibrating quartz crystal under an alternating electric field by time-resolved X-ray diffraction. The details of the experiment and application of the technique to other piezoelectric oscillators are introduced in this chapter

Intramolecular electron transfer in multi-redox systems based on cyclic [3]spirobifluorenylene compound

Cyclic [3]spirobifluorenylene with bulky alkyl groups at the ends (1) was designed and synthesized to investigate the electron transfer phenomena in a -conjugated system including orthogonal -conjugated chains. The three bifluorenyl units in 1 are conjugated to each other via spiro-conjugation, resulting in the splitting of the HOMO levels to a small extent. Therefore, the SOMO–HOMO gap of the radical cation species is small, which is considered to allow the facile intramolecular electron transfer. The electronic properties of 1 and its partial structures were characterized by absorption and fluorescence measurements and electrochemical analysis. From the electrochemical oxidation, the interchain Coulombic repulsion was observed. In the TD-DFT calculations for the radical cation species of 1, the geometry-featured interchain electronic transitions were visualized by NTO calculations. The radical cation species of 1 generated by chemical oxidation with SbCl5 exhibited a broadened and lower-energy shifted NIR absorption band compared to those of its partial structures. Considering the results of the TD-DFT calculations, the NIR band of the radical cation of 1 was attributed to the intramolecular electron transfer processes among the bifluorenyl units in the macrocycle. ESR experiments also indicated the delocalization of a spin of 1·+ in the whole molecule via hole hopping. This work demonstrates the usefulness of spiro-conjugation as a bridging unit in molecular wires to facilitate smooth electron transfer

Structures and Properties of Saturn-Like Complexes Composed of Oligothiophene Macrocycle with Methano[60]fullerene and [70]Fullerene

Ď -Expanded oligothienylene macrocycle with a large inner cavity incorporates fullerenes such as methano[60]fullerene (C61H2) and [70]fullerene (C70) inside to form Saturn-like complexes. Although the oligothiophene macrocycle weakly interacts with fullerenes in solution, it forms stable Saturn-like fullerene complexes in the solid state. X-ray analysis of the Saturn-like complexes exhibited short contacts between the sulfur atoms of the oligothiophene macrocycle and fullerene-carbons, which hinder the rotation of fullerenes. As a result, the non-covalent interaction between the oligothiophene macrocycle and fullerenes was employed in crystal structure determination of fullerenes. UV-vis-NIR spectra of the Saturn-like complexes showed weak donor-acceptor interaction between the oligothiophene macrocycle and fullerenes.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Crystallographic Structure Determination of Both [5,6]- and [6,6]-Isomers of Lithium-Ion-Containing Diphenylmethano[60]fullerene

Organic functionalization of lithium-ion-containing [60]­fullerene, Li⁺@C₆₀, was performed by using diphenyl­(diazo)­methane as a stable, readily available diazo compound to obtain lithium-ion-containing [5,6]- and [6,6]-diphenylmethano[60]­fullerenes, Li⁺@C₆₁Ph₂. The bis­(trifluoromethanesulfonyl)­imide (TFSI) salts of [5,6]- and [6,6]-Li⁺@C₆₁Ph₂ were successfully separated by using a cation exchange column with eluent containing LiTFSI. Improved separation protocol and high crystallinity of ionic components in less polar solvents enabled separate crystallization of each isomer. Both [5,6]-open and [6,6]-closed structures of Li⁺@C₆₁Ph₂ were determined by synchrotron radiation X-ray crystallography. Elucidating the [5,6]-open methano[60]­fullerene (fulleroid) structure will contribute to materials research on fulleroids

Synthesis and Crystal Structure of Li⁺@Fluoreno[60]fullerene: Effect of Encapsulated Lithium Ion on Electrochemistry of Spiroannelated Fullerene

The reaction of [Li⁺@C₆₀]­TFSI^– (TFSI = bis­(trifluoromethanesulfonyl)­imide) with 9-diazofluorene directly produced a [6,6]-adduct of lithium-ion-containing fluoreno[60]­fullerene, [6,6]-[Li⁺@C₆₀(fluoreno)]­TFSI^–, which was crystallographically characterized. Cyclic voltammetry of the compound showed a reversible one-electron reduction wave at −0.51 V (vs Fc/Fc⁺) and an irreversible reduction wave for the second electron. The latter was attributed to opening of the three-membered ring due to strong stabilization of the resulting sp³-carbanion by the encapsulated Li⁺ and formation of a 14π-electron aromatic fluorenyl anion

Facile Multiple Alkylations of C₆₀ Fullerene

The reduction of fullerene (C60) with sodium dispersion in the presence of an excess amount of dipropyl sulfate was found to yield highly propylated fullerene, C60(nC3H7)n (max. n = 24), and C60(nC3H7)20 was predominantly generated as determined by mass spectroscopy

The Effect of L-Ascorbic Acid-2-Phosphate Magnesium on Chicks Injected a Radical Initiator

Effect of L-ascorbic acid phosphate magnesium (APM) on chicks injected radical initiator, 2, 2′-azobis(2-amidinopropane) dihydrochloride (AAPH), was examined. Chicks were fed APM as ascorbate resource for 7 days. Birds were administrated AAPH by intraperitoneal injection after APM feeding. The changes of ascorbate and thiobarbituric acid reactive substances (TBARS) in plasma and liver were determined before, and 3 and 6 hours after AAPH injection. Both plasma and liver ascorbate increased by APM feeding. After AAPH injection, liver ascorbate decreased, but plasma ascorbate increased in both control and APM-fed birds. AAPH administration raised liver TBARS, but decreased plasma TBARS. Both plasma and liver TBARS were lower in APM group than control group before and after AAPH administration. Peroxyl radical trapping activity in plasma was elevated by APM feeding as compared to control group. APM was utilized as ascorbate, and was effective for prevention of oxidative stresses derived from AAPH by increasing plasma and liver ascorbate and plasma radical trapping activity

Isolation and structure determination of missing fullerenes Gd@C 74 (CF 3 ) n through in situ trifluoromethylation

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