A synthetic strategy to construct large geodesic structures of phenine (1,3,5‐trisubstituted benzene) was devised. In this strategy, five pentagons were assembled on an omphalos pentagon, and bridging peripheral pentagons furnished five additional hexagons. Thirty phenine units were synthetically assembled to afford a large C220H180 molecule with a phenine framework isoreticular to a hemispherical, bisected segment of C60. Although a hemispherical structure of the phenine framework was suggested by solution‐phase NMR spectra, crystallographic analysis revealed an oval‐like deformation of the molecular shape. In‐depth structural analyses, including theoretical calculations, showed that structural fluctuations observed as variations in the biaryl torsion angles allowed structural deformations and, at the same time, that the dynamic fluctuations resulted in the spectroscopic observation of a hemisphere as a time‐averaged structure. 相似文献
A new linear hexaphosphine, rac‐cis,cis,trans‐ bis{[(diphenylphosphinomethyl)phenylphosphinomethyl]phenylphosphino}methane ( P6 ), was synthesized and isolated as a pure isomer, confirmed by transforming to the corresponding phosphine sulfide. The methylene‐bridged linear hexaphosphine readily organized flexible gold(I) and silver(I) hexanuclear chains, [M6(μ‐ P6 )2]X6 (X6=(OTf)6, M=Au ( 1 ), Ag ( 2 ); X6=Cl2(PF6)4, M=Au ( 3 )). The hexaphosphine also supported a tetrasilver(I) complex [Ag4(μ‐ P6 )2](OTf)4 ( 4 ), which was readily transformed by treatment with AgOTf into 3 , revealing a drastic alternation of the two P6 arrangement. The hexagold(I) chains exhibited a considerably red‐shifted absorption (~410 nm) and emission (540–580 nm) to 1[5dσ*→6pσ] and from 3[5dσ*→6pσ] excited states of the metal centers, respectively. The new linear hexaphosphine could be a useful tool to construct linear metal clusters as subnano building blocks. 相似文献
The donor-acceptor-donor (D-A-D) conjugated molecules 1,4-bis(diarylaminophenylethynyl)anthraquinone (1,4-Am(2)Aq) and 1,4-bis(ferrocenylethynyl)anthraquinone (1,4-Fc(2)Aq), undergo a double proton cyclization reaction with bis(trifluoromethanesulfone)imide acid (TFSIH) to yield 1,4-bis(diarylaminophenyl or ferrocenyl) dipyrylium salts [1,4-R(2)Pyl(2)](TFSI)(2) (R=Am or Fc) with novel planar pentacyclic structures similar to the aromatic benzo[e]pyrene-type skeleton. [1,4-Am(2)Pyl(2)](TFSI)(2) could be reduced to give the neutral molecule [1,4-Am(2)Pyl(2)](0), which is stable and maintains the benzo[e]pyrene-type skeleton. To the best of our knowledge, this is the first oxygen-atom-containing polycyclic aromatic hydrocarbon with 22 (4n+2) π-electrons. The obtained condensed-ring benzo[e]pyrene-type skeleton compounds show physical and chemical properties that are significantly different from those of [1,5-Am(2)Pyl(2)](TFSI)(2), which has a perylene-type skeleton. 相似文献
Crystal extractor: Heterostructured porous coordination polymer crystals fabricated using epitaxial growth have two contradictory porous functions, namely size selectivity and high storage. The crystals not only extract linear petroleum molecules from a mixture with its branched isomer, even at very low concentrations of linear isomer (1?wt?%), but also shows improved accumulation of the molecules in its pores. 相似文献
Reactions of selenazadienes with chloroacetonitrile yielded 1,3‐selenazol‐5‐carbonitriles in moderate to high yields. Reactions of the selenazadienes with chloroacetyl chloride and then with amines gave 1,3‐sele‐nazole‐5‐carboxamides. 相似文献
The Cu-catalyzed azide-alkyne cycloaddition by the reaction of various ethynylstibanes with benzylazide in the presence of CuBr (5 mol%) under aerobic conditions led to the formation of trisubstituted 5-organostibano-1H-1,2,3-triazoles. Further, the acyl-induced deantimonation of 5-stibanotriazoles with acyl chlorides in the presence of N,N-dimethyl-4-aminopyridine and triethylamine afforded the corresponding trisubstituted 5-acyltriazoles in moderate-to-good yields. 相似文献
A new strategy to synthesize monodispersed porous coordination polymer (PCP) nanocrystals at room temperature was developed and utilized for the formation of PCP thin films on gold substrates with fine control over the crystal sizes using the coordination modulation method. Hybridization of these PCP thin films with an environment-controlled quartz crystal microbalance system allowed determining the adsorption properties for organic vapors (methanol and hexane). In the case of high sensitivity (at the low-concentration dosing of analytes), the sensor response depended on the crystal size but not on the type of analyte. In contrast, at the high-concentration dosing, a clear dependence of the sorption kinetics on the analyte was observed due to significant sorbate-sorbate interaction. 相似文献
The purpose of this study was to compare the compatibility of ROCEPHINE? Intravenous, the original manufacturer's ceftriaxone sodium preparation for injection, and seven generic versions thereof, with various calcium chloride injection 2%. The influence of calcium ion concentration, storage time and shaking strength on the appearance and quantity of insoluble microparticles in mixed solutions was examined using a light obscuration particle counter. In all products, the observed number of insoluble microparticles was proportional to the calcium ion concentration, storage time and shaking strength after the addition of calcium chloride solution. In several of the generic products, the number of insoluble microparticles was significantly higher than those of the original product, while in others it was lower. We evaluated the quality of the original and 7 generic preparations, measured the content of impurity and pH of the various ceftriaxone solutions, as impurity content and pH of solution are possible factor affecting compatibility. Three impurities were found in all products. The impurity content of several generic products, as estimated from their peak area on high performance liquid chromatography (HPLC), was significantly lower than that of the original product. pH of solution was difference between products. Although it was difficult that impurity and pH of solution verify critical factor affecting compatibility. The results show that there are differences in the appearance of insoluble microparticles between the original product and seven generic products, when calcium chloride injection 2% solution is added to the product. 相似文献
Highly effective : We report herein the first and highly efficient total syntheses of norzoanthamine and zoanthamine in full detail, which involves stereoselective synthesis of the requisite triene for an intramolecular Diels–Alder reaction via three‐component coupling reactions, the intramolecular Diels–Alder reaction, and subsequent crucial bis‐aminoacetalization as the key steps.
TAMA300, an interferometric gravitational-wave detector with 300-m baseline length, has been developed and operated with sufficient sensitivity to detect gravitational-wave events within our galaxy and sufficient stability for observations; the interferometer was operated for over 10 hours stably and continuously. With a strain-equivalent noise level of h approximately 5x10(-21)/sqrt[Hz], a signal-to-noise ratio of 30 is expected for gravitational waves generated by a coalescence of 1.4M-1.4M binary neutron stars at 10 kpc distance. We evaluated the stability of the detector sensitivity with a 2-week data-taking run, collecting 160 hours of data to be analyzed in the search for gravitational waves. 相似文献