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91.
A mixed-valence state of the cation radical tetrathiafulvalene dimer, [(TTF)2]+*, is generated by the electrochemical oxidation of a stacked TTF dimer accommodated within an organic-pillared coordination cage. This mixed-valence species is remarkably stable (t1/2 = approximately 1 day at room temperature in aqueous solution under air) and clearly characterized by cyclic voltammogram and electronic absorption spectroscopy. 相似文献
92.
93.
Koji Nakabayashi Masaki Kawano Prof. Dr. Tatsuhisa Kato Prof. Dr. Ko Furukawa Dr. Shin‐ichi Ohkoshi Prof. Dr. Toshiya Hozumi Dr. Makoto Fujita Prof. Dr. 《化学:亚洲杂志》2007,2(1):164-170
We show a new approach to manipulating the through‐space spin–spin interaction by utilizing the confined cavity of a self‐assembled M6L4 coordination cage. The coordination cage readily encapsulates stable organic radicals in solution, which brings the spin centers of the radicals closer to each other. In sharp contrast to the fact that the radical in solution in the absence of the cage is in a doublet state, in the presence of the cage through‐space spin–spin interaction is induced through cage‐encapsulation effects in solution as well as in the solid state, resulting in the triplet state of the complex. These results were confirmed by ESR spectroscopy and X‐ray crystallography. The quantity of triplet species generated by encapsulation in the cage increases with increasing affinity of the radicals to the cage. We estimated the affinity between several types of guests and the cage in solution by cyclic voltammetry. We also demonstrate that the through‐space interaction of organic radicals within the self‐assembled coordination cage can be controlled by external stimuli such as heat or pH. 相似文献
94.
Photosensitized oxygenation of diethyl sulfide in the presence of α-keto carboxylic acids caused oxidative decarboxylation of the acids by persulfoxide and gave carboxylic acids, carbon dioxide, diethyl sulfoxide and diethyl sulfone. 相似文献
95.
An improved spectrophotometric determination of uranium(VI) is proposed using 4-(2-pyridylazo)resorcinol(PAR) in the presence of benzyldimethylstearyltrimethylammonium chloride(BSTAC) as a cationic surfactant. The calibration graph is linear in the range of 0.3-60 microg/10 ml uranium(VI), measuring the absorbance at 550 nm. The reproducibility for 19.0 microg/10 ml uranium(VI) is 0.57%. The third-derivative method using the third-derivative distance (d(3)A/dlambda(3)) among lambda(1) 530 nm, lambda(3) 594 nm and lambda(2) 565 nm was also investigated. 相似文献
96.
Photooxygenation of 1,1,3,3-tetramethyl-2-indanone triphenyl-phosphazine afforded, in addition to the parent indanone and triphenylphosphine oxide, 2,2,5,5-tetramethyl-3,4-benzo-3-penten-5-olide from a carbonyl oxide intermediate and also gave light emission. 相似文献
97.
Shinsaku Fujita 《Theoretical chemistry accounts》1990,78(1):45-63
Summary A coset representation (G(/G
i
)), which is defined algebraically by a coset decomposition of a finite groupG by its subgroupG
i
, is shown to be a method for the decomposition of a regular body into its point group orbits. This proof also shows that each member of theG(/G
i
) orbit belongs to theG
i
site-symmetry. In addition, a general equation concerning the multiplicities of such coset representations is derived and shown to involve Brester's equations and thek-value equations of framework groups as special cases. The relationship of the coset representation and the site-symmetry affords a general procedure for obtaining symmetry adapted functions. 相似文献
98.
The Bose-Einstein condensation of free relativistic particles [=(M
2
c
4
+c
2
p
2
)
1/2
–Mc
2
] is studied rigorously. For massless bosons (=cp), the condensation transition of third (second) order occurs in2 (3) dimensions (D). The molar heat capacity follows the T
2
(T
3
) law below the condensation temperature Tc [k
B
Tc=(2
2
c
2
n/1.645)
1/2
[(
2
3
c
3
n/1.202)
1/3
], reaches4.38 (10.8) R at T=Tc, and approaches the high-temperature-limit value2 (3) R with no jump (a jump equal to6.75R) in2 (3)D. For finite-mass (M) bosons, the phase transition occurs only in3D with the condensation temperature Tc always smaller than that of the corresponding nonrelativistic bosons [=(2M)
–1
p
2
]. If the mass M is reduced to zero, the condensation temperature Tc grows monotonically and reaches eventually that of massless relativistic bosons. This mass-dependence of Tc is therefore distinct from the case of nonrelativistic bosons, where Tc grows to infinity as M 0. A brief discussion is given for a possible connection with the normal-to-super transition of the independently moving Cooper pairs (bosons). 相似文献
99.
100.