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131.
Ching-I Li Wen-Yann Yeh Shi-Ming Peng Gene-Hsiang Lee 《Journal of organometallic chemistry》2001,620(1-2):106-112
The perphenylmetallocene complexes (η5-C5Ph5)2W (1), [(η5-C5Ph5)2W]+I3− (1+I3), (η5-C5Ph5)2Mo (2) and [(η5-C5Ph5)2Mo]+I3− (2+I3) have been prepared. Hydrogenation of 1 in THF produces (η5-C5Ph5)2WH2 (4), while (η5-C5Ph5)2WHCl (3) is afforded in 1,2-dichloroethane solvent. Carbonylation of 1 produces (η5-C5Ph5)2W(CO) (5). Treatment of 1 with the strong acid CF3SO3H leads to the dicationic species [(η5-C5Ph5)2W]+2[CF3SO3]−2 (1+2Tf2) after crystallization. The structures of 2+I3 and 1+2Tf2 have been determined by an X-ray diffraction study. The magnetic susceptibility study indicates a 3E2g ground-state for 1 and 2, and a 4A2g ground-state for 1+ and 2+. 相似文献
132.
Schell J. Felder D. Nierengarten J.-F. Rehspringer J.-L. Lévy R. Hönerlage B. 《Journal of Sol-Gel Science and Technology》2001,22(3):225-236
Porous sol-gel glasses, either impregnated with pure C60 or doped with a methanofullerene derivative, have been studied and induced absorption or reverse saturable absorption (RSA) has been observed in both types of solid materials. The samples impregnated by pure C60 mainly contain well-dispersed fullerene molecules. Unlike crystalline films of C60, their absorption dynamics can be well described by a 5-level model, developed for non-interacting C60-molecules in solutions. Methanofullerene samples, on the other hand, show signs of micellar aggregation and therefore RSA dynamics that are influenced by solid state effects. We observe an important decrease of transmission at high fluences for both kinds of samples, a shortened singlet-state lifetime to that observed in solution, but nonetheless, a triplet yield, that cannot be considered as negligible. In the case of pure C60 in a sol-gel matrix, we can explain the faster de-excitation dynamics, relative to behavior in solution, mainly by the absence of stabilizing aromatic solvents and also by the interaction of the amorphous environment with the molecules. Concerning the methanofullerene samples, the acceleration of the de-excitation dynamics can be principally attributed to solid-state effects due to the micellar aggregation. 相似文献
133.
Signorini Raffaella Meneghetti Moreno Bozio Renato Brusatin Giovanna Innocenzi Plinio Guglielmi Massimo Negra Federico Della 《Journal of Sol-Gel Science and Technology》2001,22(3):245-253
Hybrid organic-inorganic materials are investigated as suitable materials for inclusion of fullerene derivatives and for fabrication of laser protection devices. A specific synthesis has been developed in order to optimize non-linear optical performances of fullerene derivatives. 3-glicydoxypropyltrymethoxysilane has been used as an inorganic and organic network former to obtain the host material. The sol-gel synthesis consists of the hydrolysis and condensation in acidic conditions of the inorganic network. Epoxy polymerization has been achieved by using zirconium or BF3 alkoxides precursors. Bulk and multilayer materials doped with a fullerene derivative have been fabricated. They show good optical requirements: high fullerenes concentration, high microstructural homogeneity, high laser damage threshold and high optical limiting efficiency. Optical limiting (OL) mechanisms have been investigated. The most effective in the sol-gel materials is the reverse saturable absorption (RSA) one. However, different mechanisms, like non-linear (NL) scattering and NL refraction contribute to a different extent. Open- and closed-aperture OL and z-scan measurements on sol-gel samples show the contribution of NL scattering and NL refraction at 690 nm. Laser damage threshold has been characterized as a function of the structure of the samples and of the optical configurations (f/66 and f/5). 相似文献
134.
新型双重电荷转移分子的二阶非线性光学性质的 理论研究 总被引:7,自引:0,他引:7
以INDO/SCI方法为基础,按完全态求和(SOS)公式编制了计算分子二阶非线性光学系数β~i~j~k和β~μ的程序。研究了1,2-二氨基-4,5-二硝基苯1和其异构体1,3-二氨基-4,6-二硝基苯2的电子光谱和二阶非线性光学性质。计算表明分子1具有与分子2几乎相等的二阶非线性极化率。但由于分子1的偶极矩明显大于分子2的,故分子1的μβ值比分子2的μβ值大的多。在此基础上,研究了2,3-二(β-苯乙烯基)-5,6-二氰基吡嗪和2,3-二(β-噻吩乙烯基)-5,6-二氰基吡嗪和2,3-二(β-噻吩乙烯基)-5,6二氰基吡嗪衍生物的电子光谱和二阶非线性光学性质。结果表明,这些化合物均具有两个相距很近的强吸收峰,它们对β值的呈加和模式。由于这类化合物特征吸收峰均位于413nm以下且具有大的μβ值,所以,它们是一类很有前途的二阶非线性光学候选材料。 相似文献
135.
香豆素类衍生物的合成 总被引:10,自引:0,他引:10
由人免疫缺陷病毒 ( HIV)感染引起的免疫缺陷综合症 ( AIDS)——艾滋病 ,是人类致命疾病之一。世界各国都在致力于寻找抗艾滋病药物 ,其中一个研究热点是通过大规模筛选寻找生物活性较强的小分子非肽类抑制剂 ,然后进行结构优化 ,以期找到新一代的抗艾滋病药物。香豆素类衍生物是一类具有抗病毒等许多生物活性的化合物 ,一直被人们所重视。 1 992年 ,从马来西亚热带雨林植物 Calophllum L anigerum中分离出具有抗艾滋病病毒活性的香豆素类化合物 Calanolides[1] 。同时 ,由于香豆素类化合物合成相对简单 ,生物利用度高 ,促使人们在这个… 相似文献
136.
Masumi Torii Yuki Hitora Hikaru Kato Yuhei Koyanagi Teppei Kawahara Fitje Losung Remy E.P. Mangindaan Sachiko Tsukamoto 《Tetrahedron》2018,74(52):7516-7521
Four new sulfonated serinol derivatives, siladenoserinols M–P (1–4), were isolated from a tunicate of the family Didemnidae collected in Indonesia. Their chemical structures were elucidated by the interpretation of NMR and mass spectroscopic data. Two of them (2 and 4) were revealed to be disulfonate serinol derivatives, and the others were monosulfonates. Siladenoserinols A (5) and B (6), which we previously isolated from the same tunicate, inhibited the p53–Hdm2 interaction with an IC50 value of 2.0?μM. However, 1–4 did not inhibit the activity. The result suggested that the acetyl group in the bicyclic ketal unit and/or the glycerophospholipid moiety in 5 and 6 were responsible for the inhibition of the p53–Hdm2 interaction. 相似文献
137.
《Electrophoresis》2018,39(19):2398-2405
The enantioseparation of twelve pairs of structurally related 1‐aryl‐1‐indanone derivatives was studied in the normal‐phase mode using three different polysaccharide‐type chiral stationary phases, namely Chiralpak IB, Chiralpak IC, and Chiralpak ID. n‐Hexane/2‐propanol and n‐hexane/ethanol were employed as mobile phases. Among all the investigated chiral columns, Chiralpak IC exhibited the most universal and the best enantioseparation ability toward all the racemates, particularly with the mobile phase composed of n‐hexane/2‐propanol (90/10, v/v). Then the effects of column temperature on retention and enantioselectivity were examined in the range of 25–40°C. Satisfactory enantioseparation was obtained at ambient temperature. The natural logarithm of retention and separation factors (ln k and ln α) versus the reciprocal of absolute temperature (1/T) (Van't Hoff plots) were found to be linear for all racemates, indicating that the retention and separation mechanisms were independent of temperature in the range investigated. Then, the thermodynamic parameters (ΔΔH°, ΔΔS°, and ΔΔG°) were calculated from Van't Hoff plots. These values indicated that the solute transfer from the mobile to stationary phase was enthalpically favorable, and the process of enantioseparation was mainly enthalpy controlled. At last, the impact of small changes in molecular structures of the tested 1‐indanone derivatives on enantioseparation was also discussed. 相似文献
138.
采用普通溶液法合成了配合物[Zn(eiqnthz)_2]·DMF(1)和[Zn3(piqnthz)_2Cl_2]·2H_2O(2)(Heiqnthz=N,N′-乙酰异喹啉甲酰肼,H2piqnthz=N,N′-丙酰异喹啉甲酰肼)。通过X射线单晶衍射分析、X射线粉末衍射分析、红外光谱分析、热重分析以及荧光光谱分析等分析方法对2个配合物进行结构测定和性质表征。结构分析表明配合物1是单核结构,单斜晶系,空间群为C2/c,锌离子周围有4个氮原子和2个氧原子与之配位,形成一个畸变的N4O2八面体构型。配合物2属于单斜晶系,C2/c空间群,三核结构。中心原子Zn(1)、Zn(2)、Zn(3)均为5配位,Zn(1)、Zn(3)位于分子两端并且是变形四角锥配位构型,Zn(2)位于中间形成三角双锥配位构型,整体呈V字型。荧光分析表明Heiqnthz、H2piqnthz与锌(Ⅱ)离子配位后其荧光都发生较大的红移。 相似文献
139.
140.
In this paper, a mild and green protocol has been developed for the synthesis of quinazoline derivatives. The catalytic activity of 7‐aminonaphthalene‐1,3‐disulfonic acid‐functionalized magnetic Fe3O4 nanoparticles (Fe3O4@SiO2@Propyl–ANDSA) was investigated in the one‐pot synthesis of new derivatives of tetrahydrotetrazolo[1,5‐a]quinazolines and tetrahydrobenzo[h]tetrazolo[5,1‐b]quinazolines from the reaction of aldehydes, 5‐aminotetrazole, and dimedone or 6‐methoxy‐3,4‐dihyronaphtalen‐1(2H)‐one at 100 °C in H2O/EtOH as the solvent. The catalyst was characterized before and after the organic reaction. Fe3O4@SiO2@Propyl–ANDSA showed remarkable advantages in comparison with previous methods. Advantages of the method presented here include easy purification, reusability of the catalyst, green and mild procedure, and synthesis of new derivatives in high yields within short reaction time. 相似文献