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1.
含手性原子硝基苯胺衍生的的合成及SHG效应 总被引:4,自引:0,他引:4
有机非线性光学材料具有SHG活性高,响应时间快,分子结构可变性等优点。合成了20个含不对称原子氨基酸取代的苯系化合物,测试了这些化合物的旋光度。紫外一可见吸收,SHG效应,发现17个化合物具有SHG活性,初步探讨了影响SHG效应的有关因素。 相似文献
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查尔酮系化合物的合成及SHG效应 总被引:3,自引:0,他引:3
合成了22个查尔酮系化合物,测试了它们的吸收光谱,其中19个化合物的最高吸收λmax小于400nm。采用固体粉末法测试了合成产品的SHG效应,发现13个品种具有SHG活性。 相似文献
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合成了22个查尔酮系化合物,测试了它们的吸收光谱,其中19个化合物的最高吸收λmax小于400nm。采用固体粉末法测试了合成产品的SHG效应,发现13个品种具有SHG活性. 相似文献
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对硝基苯胺衍生物的合成及SHG效应 总被引:4,自引:0,他引:4
合成了十个对硝基苯胺衍生物,其中4个化合物含有手性原子。测试了它们的旋光度、和吸收光谱,含手性原子的化合物均有旋光值,十个合成产品的最高吸收波长在307 ̄390nm之间。采用固体粉末法测试了合成化合值的SHG效应,其中五个品种具有SHG活性。 相似文献
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芳胺与四种取代苯甲醛缩合,合成了20个希夫碱化合物,进行重结晶提纯,讨论了希夫碱的分解与分解抑制。测试了希夫碱化合物的紫外 可见吸收曲线及SHG效应,发现有7个化合物有倍频效应,其中两个倍频能力高于尿素,讨论了取代基对λmax、Δλ1/2max及SHG效应的影响。 相似文献
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芳醛与芳胺的缩合反应及产物的倍频效应 总被引:5,自引:0,他引:5
三种芳醛与芳胺缩合,合成了14个希夫碱化合物,讨论了催化剂、空间效应对缩合反应的影响。测试了14个希夫碱的紫外-可见吸收曲线及SHG效应,发现有一个化合物有倍频效应,并讨论了取代基对λmax及Δλ1/2max的影响 相似文献
8.
H2SO4石墨层间化合物稳定性分析研究 总被引:3,自引:0,他引:3
本文用日本理学转靶X射线分析仪D/MAX/B首次制定了H2SO4-石墨层间化合物在各种条件下的X射线衍射图谱,根据各X射线衍射图,对H2SO4-GIC的阶结构进行了详尽的分析,探讨了环境对H2SO4-GIC隐定性的影响。在测试过程中采用特殊的样品制备方法,保证了H2SO4-GIC衍射图谱的客观性. 相似文献
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可膨胀石墨中有害硫的研究 总被引:4,自引:0,他引:4
通过GIC合成工艺实验,对H2SO4-GIC的有害元素S进行了分析研究,找出了影响含硫量的因素、提出了具有最低含硫量的工艺条件,并得出了H2SO4-GIC中硫的分布情况。 相似文献
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以氯甲基化苯氧基聚丙二醇(CMPPG)为大分子引发剂,CuCl/bpy为催化体系研究了CMPPG-g-PS共聚物的合成。结果表明,该聚合过程具有活性聚合特征,借助1H-NMR表征确认了接枝共聚物具有预期结构。 相似文献
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New polymeric photobase generators containing oxime–urethane groups were prepared by the polyaddition reaction of 2,4‐tolylene diisocyanate with terephthalaldehyde dioxime in the presence or absence of a polyol component to study the ability of these polymers to generate amines through the photolysis of oxime–urethane linkage. The amines induced the crosslinking of poly(glycidyl methacrylate), as proved by the variation of the amount of the insoluble fraction of polymer films with the heating temperature and/or irradiation time. UV and IR absorption spectra indicated that the thermal crosslinking of poly(glycidyl methacrylate) was catalyzed by the photogenerated amines. The photobehavior of the polymers was followed by a reduction of the absorption band at 290 nm, which was characteristic of oxime–urethane groups, as a function of the UV irradiation time. Blue fluorescence was visualized by the treatment of irradiated films with fluorescamine. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2324–2332, 2004 相似文献
13.
Henning Nielsen 《Lipids》1981,16(4):215-222
Various peroxidized phospholipids were reacted with proteins under N2. In all cases, phospholipid is bound covalently to the proteins whose molecular size is increased. Both the amount of bound
phospholipid and the increase in molecular size of the protein depends on the nature of the phospholipid. Ultraviolet (UV)
absorption of the proteins is increased in qualitatively similar ways. Their difference spectra, which show a gradual increase
in absorption from 400 nm toward shorter wavelength, differ from that of malonaldehyde-protein complexes. The various complexes
of proteins and peroxidized phospholipids have similar fluorescence spectra showing two excitation maxima at 310–320 nm and
at 340–350 nm, respectively, and emission maximum at ca. 400 nm. This is different from both fluorescence spectra of malonaldehyde-protein
complexes and fluorescence spectra reported for proteins after reaction with peroxidized polyunsaturated fatty acids. Amino
groups of the proteins are consumed in the reaction with peroxidized phospholipids. Blocking the amino groups decreases the
binding of phospholipid considerably. Besides amino groups, other structures of the protein molecule react with the peroxidized
phospholipids. The similar features of UV absorption, fluorescence, decrease of amino groups, and covalently bound phospholipid
phosphorus of the various complexes suggest that they are formed by common type of reactions. The reactions seem to be different
from those generally believed important between peroxidized lipid and protein. Important reacting species are compounds other
than malonaldehyde.
Preliminary report of this work was presented at the ISF/AOCS World Congress, New York, 1980. 相似文献
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采用紫外可见光谱作为检测2,4-二硝基苯酚的方法,pH6或pH3时,2,4-二硝基苯酚的特征吸收峰分别为370 nm及260 nm处;在pH 3~6之间,两特征峰共存。文章提出一种简单的归一拟合方法,首先推导出260 nm处的吸收值与浓度的线性关系,再将pH不同的2,4-二硝基苯酚在370 nm处的吸收值校正到260 nm处。开发了一种简单快捷无需调节pH测定2,4-二硝基苯酚浓度的方法。 相似文献
16.
《Journal of Industrial and Engineering Chemistry》2014,20(4):1280-1284
Zn/Al-layered double hydroxides (LDHs) containing the organic anion of 2,4-dihydroxybenzophenone-5-sulfonate (DHBS) have been synthesized by co-precipitation method. Surface, structural, thermal and absorption properties of the ZnAl-DHBS-LDHs nanohybrids were characterized by BET analysis, scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry and differential thermal analysis and UV–visible spectroscopy. The results revealed that organic UV absorbent-DHBS has been intercalated into the interlayer spaces of ZnAl-LDHs and the intercalation of DHBS in LDHs interlayer galleries resulted to higher thermal stability and better UV absorption ability; these show that the hybrid ZnAl-DHBS-LDHs phase has potential applications as a UV absorber. 相似文献
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三嗪型紫外线吸收剂的合成及性能 总被引:1,自引:1,他引:1
用格氏试剂偶联法合成了4个有代表性的三嗪型紫外线吸收剂:2,4-双(2,4-二羟基苯基)-6-(4-甲氧基苯基)-1,3,5-三嗪、2,4-双(2,4-二羟基苯基)-6-苯基-1,3,5-三嗪、2-(2,4-二羟基苯基)-4,6-二苯基-1,3,5-三嗪和2,4,6-三(2,4-二羟基苯基)-1,3,5-三嗪,测定了它们的紫外光谱。其中,2,4-双(2,4-二羟基苯基)-6-(4-甲氧基苯基)-1,3,5-三嗪在UVB和UVA都有较强吸收,εmax=36000L/(mol.cm)(λmax=313nm),εmax=36333L/(mol.cm)(λmax=344nm),是其中最好的紫外线吸收剂。 相似文献
19.
Justyna Popi Agnieszka Gunia-Krzyak Karolina Soczyska Paulina Koczurkiewicz-Adamczyk Kamil Piska Katarzyna Wjcik-Pszczoa Dorota elaszczyk Anna Krupa Pawe mudzki Henryk Marona Elbieta Pkala 《International journal of molecular sciences》2021,22(1)
Excessive UV exposure contributes to several pathological conditions like skin burns, erythema, premature skin aging, photodermatoses, immunosuppression, and skin carcinogenesis. Effective protection from UV radiation may be achieved with the use of sunscreens containing UV filters. Currently used UV filters are characterized by some limitations including systemic absorption, endocrine disruption, skin allergy induction, and cytotoxicity. In the research centers all over the world new molecules are developed to improve the safety, photostability, solubility, and absorption profile of new derivatives. In our study, we designed and synthesized seventeen novel molecules by combining in the structures two chromophores: xanthone and (E)-cinnamoyl moiety. The ultraviolet spectroscopic properties of the tested compounds were confirmed in chloroform solutions. They acted as UVB or UVA/UVB absorbers. The most promising compound 9 (6-methoxy-9-oxo-9H-xanthen-2-yl)methyl (E)-3-(2,4-dimethoxyphenyl)acrylate) absorbed UV radiation in the range 290–369 nm. Its photoprotective activity and functional photostability were further evaluated after wet milling and incorporation in the cream base. This tested formulation with compound 9 possessed very beneficial UV protection parameters (SPFin vitro of 19.69 ± 0.46 and UVA PF of 12.64 ± 0.32) which were similar as broad-spectrum UV filter tris-biphenyl triazine. Additionally, compound 9 was characterized by high values of critical wavelength (381 nm) and UVA/UVB ratio (0.830) thus it was a good candidate for broad-spectrum UV filter and it might protect skin against UVA-induced photoaging. Compound 9 were also shown to be photostable, non-cytotoxic at concentrations up to 50 µM when tested on five cell lines, and non-mutagenic in Ames test. It also possessed no estrogenic activity, according to the results of MCF-7 breast cancer model. Additionally, its favorable lipophilicity (miLogP = 5.62) does not predispose it to penetrate across the skin after topical application. 相似文献