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1.
用INDO/SDCI方法研究了酞菁和酞菁铜的电子结构, 紫外-可见光谱, 三阶非线性光学系数及其色散效应, 发现酞菁铜中Cu^2+对γ的贡献很小, 故酞菁与酞菁铜的γ几乎相等, 我们的计算结果对此进行了合理的解释。 相似文献
2.
In the present work, 4-(4′-dodecyloxycarbonyl) phenoxy phthalonitrile was synthesized and then this phthalonitrile derivative was cyclotetramerized in dodecanol resulting a new metal-free phthalocyanine. The optical properties of this phthalocyanine were investigated. Novel metal-free phthalocyanine thin films were deposited on indium tin oxide-coated glass substrates by spinning method. Surface and microstructural properties of the films were characterized by atomic force microscopy and scanning electron microscopy. Both the transmittance and reflectance spectra of the deposited films were recorded using an NKD analyser. The optical band gap energy, the thickness of thin films, refractive index ( n) and extinction coefficient ( k) were calculated as 2.7 eV, 300 nm, 1.47 and 0.02, respectively. 相似文献
4.
Due to the well‐known optical limiting properties of indium (III) phthalocyanines (In [III] Pcs) and aiming at extending their conjugation system, a highly branched indium phthalocyanine polymer was prepared. Flash chromatography was used for obtaining a pure polymer of polydispersity index near to the unity. The structure of the prepared polymer was determined using different spectroscopic techniques. Optical limiting and open aperture Z‐scan measurements were carried out according standard procedures. Compared with many other phthalocyanines, the prepared indium‐phthalocyanine polymer shows a high optical limiting performance that is indicated by a relatively low limiting threshold of 430 mJ cm ?2 and a large nonlinear absorption coefficient ( α2 = 3.4 × 10 ?8 cmW ?1). Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
5.
Phthalocyanine coated electrodes are of interest due to their high electrochemical and electrocatalytical activities. Several possibilities to prepare electrodes coated by polymeric phthalocyanine and its precursor are described. Examples of electrochemical (reduction/reoxidation of the films) as well as electrocatalytical properties are presented. 相似文献
6.
利用AM1方法计算多种酞菁不对称取代物的电子结构与非线性光学特性,并探讨它们之间的关系。结果表明偶极矩μ,能级差△E~D~A,电荷转移△Q~D~A与二阶非线性光学系数β之间都存在一定的规律性,其中μ与β和△E~D~A与β之间的关系较为明显,并有相似趋势。 相似文献
7.
We report both the preparation and sensor evaluation of a new metal-free calixarene bridged binuclear phthalocyanine. 相似文献
8.
A new hydrothermal synthesis of manganite is described, and the magnetic and electron paramagnetic resonance (EPR) behavior of the product is reported. The magnetic susceptibility is nearly independent of temperature above 90°K and increases dramatically on cooling to 30°K. The EPR lineshape, linewidth, and g-factor at 296°K are Lorentzian (in the central region), 280 ± 10 G, and 1.997 ± 0.006, respectively. The EPR spectrum is interpreted in terms of nearly one-dimensional interactions between identical Mn moments. The results of this study support the view that all Mn ions are trivalent and that the magnetic interactions between these ions are nearly one dimensional. 相似文献
9.
The 4-[4′-(5-sulfonaphthylazo)phenoxy]phthalonitrile potassium salt was synthesized by the reaction of 4-chlorophthalonitrile
with 5-(4′-hydroxyphenylazo)-1-naphthalenesulfonic acid, and on its basis was obtained tetra-4-[4′-(5-sulfonaphthylazo)phenoxy]phthalocyanine.
The products were characterized by elemental analysis, IR and electron spectroscopy. The effect of the introduced substituent
on the spectral and other properties of the synthesized compounds was demonstrated. 相似文献
10.
Using density functional theory, we consider the adsorption of C on graphene, which gives rise to many interesting phenomena. A single-C at the bridge site shows a clearly covalent-bond feature with graphene, in which the metallic state occurs and a magnetic moment of 0.36 μ(B) was determined. For both-sided adsorption, the magnetic moment is remarkably larger than that in one-sided adsorption, and increases with concentration up to a coverage of 12.5%. High spin polarization obtained at the Fermi level indicates a high degree of passage of preferred spin, which is important for developing spin filters. 相似文献
11.
采用水热法合成超顺磁性Fe_3O_4纳米微球,随后在Fe_3O_4纳米微球表面功能化含有卤胺结构的N,N’-亚甲基双丙烯酰胺与聚丙烯酸共聚物,并进一步用次氯酸钠处理得到Fe_3O_4@poly(MBAA-co-AA)-Cl抗菌剂.该抗菌剂平均粒径200 nm,具有很好的分散性及生物相容性,对大肠杆菌和金黄色葡萄球菌均具有抗菌性.当样品浓度为6.0 g/L时,其对大肠杆菌的杀菌率和金黄色葡萄球的杀菌率分别为99.32%和98.93%;样品浓度增加为7.5 g/L时,两种细菌的失活率均可达到100%.同时该抗菌剂杀菌速度快、性能稳定、可再生,通过10次循环氯化处理后,其氧化态氯含量几乎与原始值相同,细菌的失活率也均能达到98%以上,是一种优良、高效的纳米抗菌剂. 相似文献
12.
We investigated the effects of lithium bromide (LiBr) on the structure and properties of polyamide 6 (PA6). The strong ion–dipole interactions between lithium cations and the amide groups in PA6 greatly increased the glass transition temperature ( Tg) and retarded the crystallization rate of PA6. As a result, compression-molded PA6 blends were highly transparent and had high Tg values. The rheological terminal region was obvious in the blends because the ion–dipole interactions weakened at high temperatures. This indicates that the melt processability was barely affected by LiBr. We also evaluated the optical anisotropy of the polymer to determine its suitability as a functional optical film. We found that hot-stretched blend films had large positive orientation birefringence with significantly weak wavelength dispersion, which can be attributed to the enhanced anisotropic polarizability of PA6. We also found that the stress-optical coefficient in the glassy region decreased with increasing LiBr content. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1513–1520 相似文献
14.
A lithium phthalocyanine radical and the analogous aluminum phthalocyanine radical were synthesized as part of an investigation of isostructural dopants. An improved synthesis of the free base of octa(pentoxy)phthalocyanine (H 2Pc*) involves the reduction of 1,2-dicyano-4,5-dipentoxybenzene with hydroquinone. Deprotonation with lithium bis(trimethylsilyl)amide leads to the dilithium derivative Li 2Pc* and subsequent oxidation with ferrocenium yields the radical LiPc*. Treatment of H 2Pc* with Et 2AlCl gives ClAlPc* and reduction with sodium amalgam yields AlPc*, the first reported aluminum phthalocyanine radical. In the solid state LiPc* and AlPc* are electrical conductors with pressed-pellet conductivities of 8 × 10 −11 Ω −1 cm −1 and 5 × 10 −7 Ω −1 cm −1, respectively. 相似文献
15.
Peritetracene (PTA) molecules have promising applications in organic electronics and organic light-emitting diodes, but the major constraints come from their poor stability with higher energy gap. We have investigated the stability, electronic, and optical properties of different electron-donating- and electron-withdrawing-substituted PTA molecule groups using density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods. On substituting suitable electron donor and acceptor groups, the energy gap of PTA molecules reduces up to 0.37 eV with an increase in their stability. The stabilities of considered PTA molecules have been investigated using the distribution pattern of frontier molecular orbital energies. The charge transfer properties with smaller ionization potential and larger electron affinity for PTA molecule have been evaluated using Koopmans’ theorem. Enhancement in dipole moment, polarizability, and hyperpolarizability of PTA substituted with electron-donating groups shows the presence of NLO properties. Also, we have investigated the spectroscopic properties of different electron-donating- and electron-withdrawing-substituted PTA molecule groups. Our spectroscopic properties show the bathochromic shift and small hypsochromic shifts in wavelengths of PTA with substituents groups. It is therefore concluded that the –NCH3 and –NO2 substituent groups on PTA are observed to have the strongest and highest stability than the other substituent groups considered. 相似文献
17.
We review recent studies of double-decker and triple-decker phthalocyanine (Pc) molecules adsorbed on surfaces in terms of the bonding configuration, electronic structure and spin state. 相似文献
18.
A type of worm-like nanorods was successfully synthesized through conventional gold nanorods reacting with Na2S2O3 or Na2S. The generated worm-like gold nanorods comprise shrunk nanorod cores and enwrapped shells. Therefore, a gold-gold sulfide core-shell structure is formed in the process, distinguishing from their original counterparts. The formation of the gold chalcogenide layers was confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy. Experimental results showed that the thickness of the gold chalcogenide layers is controllable. Since the increase of shell thickness and decrease of gold nanorod core take place simultaneously, it allows one to tune the plasmon resonance of nanorods. Proper adjustment of reaction time, temperature, additives and other experimental conditions will produce worm-like gold nanorods demonstrating desired longitudinal plasmon wavelength (LPW) with narrow size distributions, only limited by properties of starting original gold nanorods. The approach presented herein is capable of selectively changing LPW of the gold nanorods. Additionally, the formed worm-like nanorods possess higher sensitive property in localized surface plasmon resonance than the original nanorods. Their special properties were characterized by spectroscopic methods such as Vis-NIR, fluorescence and resonance light scattering. These features imply that the gold nanorods have potential applications in biomolecular recognition study and biosensor fabrications. 相似文献
19.
Metal–carbon nanocomposites that represent FeCo alloy nanoparticles uniformly distributed over the carbon matrix, were prepared by the IR pyrolysis of precursors comprising polyacrylonitrile (PAN), iron acetylacetonate, and cobalt acetate (the metal ratio in the precursors was Fe: Co = 1: 1, 3: 1). The composition of FeCo alloy nanoparticles satisfies the tailored ratio Fe: Co. The FeCo phase is formed at synthesis temperatures in the range 500–600°С; at T ≤ 500°С only FCC-Co-base solid solutions are observed. The nanocomposites prepared at T ≥ 600°С simultaneously contain FeCo intermetallic nanoparticles and an insignificant amount of a FCC-Co phase or a cobalt-base solid solution phase. The saturation magnetization of FeCo/C metal–carbon nanocomposites is determined by the mean nanoparticle size and the alloy composition, and ranges from 36 to 64 (A m 2)/kg (when Fe: Co = 1: 1) and from 35 to 52 (A m 2)/kg (when Fe: Co = 3: 1) at synthesis temperatures in the range 600–800°С. 相似文献
20.
滴定水解法制备的Fe3O4磁流体,与单体N-异丙基丙烯酰胺(NIPAM)和α-甲基丙烯酸(MAA),在一定的条件下沉降聚合,制备了Fe3O4/P(NIPAM-MAA)复合微粒.对其形态及性能进行研究表明,复合微粒呈现核壳结构的规则球形,溶胀态和收缩态的平均粒径分别为334.7nm和141.5nm.复合颗粒中的Fe3O4颗粒质量分数为1.9%,当外磁场为104Oe时,复合微粒的饱和磁化强度(Ms)为0.6306emu/g.分散在水溶液中的复合微粒在30℃~36℃之间发生了体积相转变,表现出温度敏感性.在低pH溶液中的体积相转变十分显著,随pH逐渐增大,其体积相转变温度(VPTT)显示向高温迁移. 相似文献
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