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1.
采用激光闪光光解技术测定了系列八烷氧基萘酞菁锌配合物ZnNc(OR)8(R=C4H9,C8H17,C12H25)激发三重态的寿命,研究了该系列化合物光敏化产生单重态氧的能力和对HL60癌细胞的光动力活性,并探讨了它们作为光敏剂在肿瘤光动力治疗中的光敏反应机制。  相似文献   

2.
在无水乙醇中, 合成了组成为RE(C5H8NS2)3(C12H8N2) (RE=La, Pr, Nd, Sm~Lu) 的固态配合物. IR光谱表明配合物中稀土离子(RE3 )与吡咯烷二硫代氨基甲酸铵 (APDC)中的硫原子和1, 10-邻菲咯琳(o-phen) 中的氮原子均双齿配位; UV光谱显示配合物中o-phen与稀土离子之间的能量传递是主要过程, 配合物的最大吸收与o-phen相比有微小的红移; FS光谱表明配合物Sm(C5H8NS2)3(C12H8N2)和Eu(C5H8NS2)3(C12H8N2)具有很强的荧光性质.  相似文献   

3.
利用真空紫外同步辐射和反射式飞行时间质谱研究了乙苯分子的光电离, 通过测量母体分子的光电离质谱(PIMS)以及母体离子和主要碎片离子的光电离效率曲线(PIEs), 确定了乙苯分子的电离能IE(C8H+10)=(8.66±0.02) eV, 主要碎片离子C7H+7和C6H+6的出现能分别为(10.81±0.02)和(10.99±0.02) eV; 利用经验公式计算出产生碎片离子C7H+7和C6H+6需要的解离能(Ed)分别为(2.15±0.04)和(2.33±0.04) eV. 结合相关的热化学参数, 推算出C8H+10, C7H+7和C6H+6的标准生成焓分别为865.5, 927.2和1037.9 kJ/mol. 为进一步研究乙苯的大气光氧化反应机理提供了参考.  相似文献   

4.
合成得到3-(5-氨基-萘氧基)邻苯二甲腈(C18H11N3O)、4-(5-氨基-萘氧基)邻苯二甲腈(C18H11N3O)、3-联苯氧基邻苯二甲腈(C20H12N2O)及4-联苯氧基邻苯二甲腈(C20H12N2O)4种未见报导的取代邻苯二甲腈,以此为前躯体合成了四[α-(5-氨基-萘氧基)]酞菁锌(C72H44N12O4Zn)、四[β-(5-氨基-萘氧基)]酞菁锌(C72H44N12O4Zn)、四[α-(联苯氧基)]酞菁锌(C80H48N8O4Zn)和四[β-(联苯氧基)]酞菁锌(C80H48N8O4Zn)4种未见报导的芳氧基取代酞菁锌配合物。通过测定它们的紫外-可见吸收光谱、荧光发射光谱,获得其最大吸收波长及其摩尔消光系数、最大发射波长、荧光量子产率(ΦF)、单线态氧量子产率(ΦΔ)及光降解速率常数并与其类似物进行了比较,探讨了它们的光物理光化学性质的构效关系。研究结果表明四[α-(联苯氧基)]酞菁锌在红光区具有大的摩尔消光系数,且具有较高的ΦΔ,有望开发成为光动力治疗用光敏剂。  相似文献   

5.
利用超声分子束、真空紫外同步辐射和反射式飞行时间质谱仪开展1,3,5-三甲基苯(TMB,C9H12)的光电离和光解离研究.利用光电离质谱和光电离效率曲线,确定母体分子的电离能,主要碎片离子C9H+11和C8H+9的出现能分别为(8.32±0.03),(11.71±0.03)和(11.59±0.03)eV.根据经验公式,计算出形成C9H1+1和C8H+9的解离能(Ed)分别为(3.39±0.06)和(3.27±0.06)eV.再利用相关的热化学参数,推算出C9H1+2,C9H+11和C8H+9的标准生成焓为786.87,897.93和956.68kJ/mol.  相似文献   

6.
用量子化学从头计算方法, 研究了Ti8C12分别与H2O, C2H4作用形成Ti8C12(H2O)8, Ti8C12(C2H4)4的反应。计算结果表明, 在Ti8C12(H2O)8中, 电子由H2O向Ti8C12转移, 在Ti8C12(C2H4)4中, 电子由Ti8C12向C2H4转移。从Ti8C12生成Ti8C12(H2O)8能量降低, 稳定性增加, 生成Ti8C12(C2H4)4能量升高, 稳定性减小。  相似文献   

7.
用量子化学从头计算方法, 研究了Ti8C12分别与H2O, C2H4作用形成Ti8C12(H2O)8, Ti8C12(C2H4)4的反应。计算结果表明, 在Ti8C12(H2O)8中, 电子由H2O向Ti8C12转移, 在Ti8C12(C2H4)4中, 电子由Ti8C12向C2H4转移。从Ti8C12生成Ti8C12(H2O)8能量降低, 稳定性增加, 生成Ti8C12(C2H4)4能量升高, 稳定性减小。  相似文献   

8.
中文:采用密度泛函理论方法(B3LYP和BP86)在6-311+G(d,p)基组水平上系统研究了新颖的铍-铍金属链夹心配合物[Ben(C4H4)2]2- 及 [Ben(C4H4)2]Li2 (n=2–8) 的几何结构、电子结构、成键特征及热力学稳定性。结果表明,具有交错式D4d 对称性的[Ben(C4H4)2]2-及[Ben(C4H4)2]Li2 为体系势能面上的真正极小。自然键轨道(NBO)、分子中的原子(AIM)及分子轨道分析表明该系列夹心配合物中铍-铍间主要以共价键为主,而配体与铍-铍链之间则主要以离子键为主。核独立化学位移(NICS)分析表明配体在该系列配合物中具有π芳香性。稳定的夹心配合物锂盐[Ben(C4H4)2]Li2 (n=2–8)有望通过C4H4Li2/C5H5-配体交换反应进行制 备,该系列配合物将进一步丰富多核夹心配合物研究领域。  相似文献   

9.
用量子化学从头计算方法,研究了Ti8C12分别与H2O,C2H4作用形成Ti8C12(H2O)8,Ti8C12(C2H4)4的反应.计算结果表明,在Ti8cC12(H2O)8中,电子由H2O向Ti8cC12转移,在Ti8cC12(C2H4)4中,电子由Ti8cC12向C2H4转移.从Ti8cC12生成Ti8cC12(H2O)8能量降低,稳定性增加,生成Ti8cC12(C2H4)4能量升高,稳定性减小.  相似文献   

10.
牛淑云  张亚玲  来巍  杨忠志  杨光第  叶玲 《化学学报》2001,59(12):2170-2175
以Nd(NO3).6H2O和NH2C6H4COOH为原料,经[Nd(C7H6NO2)3.H2O]的自组装,得到了具有三维网络结构的配位聚合物[Nd(C7H6NO2)3.H2O]n。该聚合物晶体属单斜晶系,空间群P2(1)/n,a=0.98069(5)nm,b=2.2736(2)nm,c=0.98254(8)nm,β=100.053(5)°,V=2.1571(3)nm^3,Z=4。最后的一致性因子R=0.038。磁性研究表明,该化合物在低温下表现出反铁磁性质。测定了化合物的UV-vis-NIR和IR光谱,进行了分析和指认。  相似文献   

11.
The present study reports the effect a cell permeabilizer, polyethylenimine (PEI) has on the photodynamic effect of methylene blue (MB) and nuclear fast red (NFR) in the presence of hydrogen peroxide (H2O2). The photosensitized destruction of the algae Chlorella vulgaris under irradiation with visible light is examined. The photodynamic effect was investigated under aerobic and anaerobic conditions. The presence of a permeabilizer during the photosensitized destruction of C. vulgaris does not enhance the activity of the MB, MB/H2O2 system or the NFR, NFR/H2O2 system under aerobic conditions. However under anaerobic conditions we have determined that when a cell permeabilizer was added to the MB/H202 system, the photosensitized destruction of C. vulgaris proceeded via a combination of Type I and Type II mechanisms. The presence of PEI enforces MB/H2O2 to be active toward the destruction of C. vulgaris whether oxygen is present or absent. Under aerobic and anaerobic conditions the activity of NFR was suppressed in the presence of PEI as a result of electrostatic interactions between the photosensitizer and the cell permeabilizer. The decrease in fluorescence recorded is indicative of destruction of the chlorophyll a pigment.  相似文献   

12.
We report the synthesis of porphyrazines (pzs), or tetraazaporphyrins, of the form H2[pz(An;B4-n)], where A is [S(CH2)3COOR]2 (R = n-Pr,H) and B is a fused beta,beta'-diisopropyloxybenzo group, including the compounds with n = 4 (6), n = 3 (7) and the trans compound with n = 2 (8) (Scheme 1). The synthesis employs Linstead crossover macrocyclization of dimethyl 6,7-dicyano-5,8-dithia-6(Z)-dodecenedioate, MNT(C4O2Me)2 (2), with 1-imino-4,7-bis(1-methylethoxy)-1H-isoindole-3-amine (4). These pigments were characterized by 1H NMR, 13C NMR, absorbance/fluorescence spectroscopy, mass spectrometry, and microanalysis. An X-ray crystal structure of 8 is presented. Of particular note, 6-8 display intense near-IR absorbance and dual UV-visible/near-IR emission which are very important in potential biomedical applications, both for cancer therapy (photodynamic therapy, PDT) and cancer diagnosis (optical tumor imaging). For example, the trans-porphyrazine 8 has an intense long-wavelength absorption at ca. 800 nm (log epsilon = 4.18) and S1 fluorescence at approximately 820 nm, where mammalian tissue is effectively penetrated by light. Transformation of the ester group permits a wide range of functionality and solubility to be generated without change in optical properties. As an example, hydrolysis of these compounds by LiOH in THF/H2O gives the corresponding carboxylato-functionalized pigments 9-11, which are described. The last of these dissolves without aggregation in fetal calf serum.  相似文献   

13.
A study has been carried out to define the importance of the peripheral benzodiazepine receptor (PBR) as a binding site for a series of chlorin-type photosensitizers, pyropheophorbide-a ethers, the subject of a previous quantitative structure-activity relationship study by us. The effects of the PBR ligand PK11195 on the photodynamic activity have been determined in vivo for certain members of this series of alkyl-substituted ethers: two of the most active derivatives (hexyl and heptyl), the least active derivative (dodecyl [C12]) and one of intermediate activity (octyl [C8]). The photodynamic therapy (PDT) effect was inhibited by PK11195 for both of the most active derivatives, but no effect on PDT activity was found for the less active C12 or C8 ethers. The inhibitory effects of PK11195 were predicted by the binding of only the active derivatives to the benzodiazepine site on albumin, ie. human serum albumin (HSA)-Site II. Thus, as with certain other types of photosensitizers, it has been demonstrated with this series of pyropheophorbide ethers that in vitro binding to HSA-Site II is a predictor of both optimal in vivo activity and binding to the PBR in vivo.  相似文献   

14.
Ti(C5H5)2(C8H4S8) (1), Ti(C5Me5)2(C8H4S8) (2), [NMe4][Ti(C5H5)(C8H4S8)2] (3), and [NMe4][Ti(C5Me5)(C8H4S8)2] (4) [C8H4S8(2-) = 2-(4,5-ethylenedithio)-1,3-dithiole-2-ylidene)-1,3-dithiole-4,5- dithiolate(2-)] were prepared by reaction of Ti(C5H5)2Cl2, Ti(C5Me5)2Cl2, Ti(C5H5)Cl3, or Ti(C5Me5)Cl3 with Li2C8H4S8 or [NMe4]2[C8H4S8] in THF. They were oxidized by iodine, the ferrocenium cation, or TCNQ (7,7,8,8-tetracyano-p-quinodimethane) in CH2Cl2 or in acetone to afford one-electron-oxidized and over-one-electron-oxidized species, [Ti(C5H5)2(C8H4S8)].I3, [Ti(C5H5)2(C8H4S8)][PF6], [Ti(C5Me5)2(C8H4S8)].I3, [Ti(C5Me5)2(C8H4S8)][PF6], [Ti(C5H5)(C8H4S8)2].I0.9, [Ti(C5H5)(C8H4S8)2][TCNQ]0.3, [Ti(C5Me5)(C8H4S8)2].I2.4, and [Ti(C5Me5)(C8H4S8)2][TCNQ]0.3, with the C8H4S8 ligand-centered oxidation. They exhibited electrical conductivities of 1.6 x 10(-1) to 7.6 x 10(-4) S cm-1 measured for compacted pellets at room temperature. The crystal structure of 2 was clarified to consist of isolated dimerized units of the molecules through some sulfur-sulfur nonbonded contacts: monoclinic, P2(1)/c, a = 9.534(2) A, b = 18.227(2) A, c = 17.775(2) A, beta = 94.39(1) degrees, Z = 4.  相似文献   

15.
Gadolinium (Gd) complexes of benzene (C(6)H(6)) and (1,3,5,7-cyclooctatetraene) (C(8)H(8)) were produced in a laser-vaporization supersonic molecular beam source and studied by single-photon pulsed-field ionization zero electron kinetic energy (ZEKE) spectroscopy. Adiabatic ionization energies and metal-ligand stretching frequencies were measured for the first time from the ZEKE spectra. Metal-ligand bonding and electronic states of the neutral and cationic complexes were analyzed by combining the spectroscopic measurements with ab initio calculations. The ground states of Gd(C(6)H(6)) and [Gd(C(6)H(6))](+) were determined as (11)A(2) and (10)A(2), respectively, with C(6v) molecular symmetry. The ground states of Gd(C(8)H(8)) and [Gd(C(8)H(8))](+) were identified as (9)A(2) and (8)A(2), respectively, with C(8v) molecular symmetry. Although the metal-ligand bonding in Gd(C(6)H(6)) is dominated by the covalent interaction, the bonding in Gd(C(8)H(8)) is largely electrostatic. The bonding in the benzene complex is much weaker than that in the cyclooctatetraene species. The strong bonding in Gd(C(8)H(8)) arises from two-electron transfer from Gd to C(8)H(8), which creates a strong charge-charge interaction and converts the tub-shaped ligand into a planar form. In both systems, Gd 4f orbitals are localized and play little role in the bonding, but they contribute to the high electron spin multiplicities.  相似文献   

16.
Mo_2(C_8H_8)_3是由Mo(CO)_6和环辛四烯在正癸烷中回流而制得。它的晶体属单斜晶系,空间群为P2_1,单胞参数为:a=7.772(3),b=11.964(5),c=10.445(2),β=100.33(2)°,V=955(1)~3,根据Z=2和fw=504.31计算密度Dc=1.75g/cm~3。在Enraf-Nonius CAD4衍射仪上用MoKα射线收集了I>2σ(I)的独立衍射点2393个。晶体结构用直接法(MULTAN)程序解出,所有非氢原子的位置参数和各向异性热振动参数经全矩阵最小二乘法修正,最后的偏离因子R_1(F)=0.030,R_2(F)=0.035。分子中钼—钼的距离为2.293(1),形成了Mo-Mo四重键。Mo_2(C_8H_8)_3存在两种晶型;一是与W_2(C_8H_8)_3同晶;另一是与Cr_2(C_8H_8)_3同晶。  相似文献   

17.
Abstract The mode of cell death following photodynamic therapy was investigated from the perspective of programmed cell death or apoptosis. Human prostate carcinoma cells (PC3), human non-small cell lung carcinoma (H322a) and rat mammary carcinoma (MTF7) were treated by photodynamic therapy. An examination of extracted cellular DNA by gel electrophoresis showed the characteristic DNA ladder indicative of internucleosomal cleavage of DNA during apoptosis. The magnitude of the response and the photodynamic therapy dosage required to induce DNA fragmentation were different in PC3 and MTF7. The MTF7 cells responded with rapid apoptosis at the dose of light and drug that yielded 50% cell death (LD50). In contrast, PC3 showed only marginal response at the LD50 but had a marked response at the LD85. Thus, apoptosis did not ensue as quickly in PC3 as in MTF7. The H322a cells were killed by photodynamic therapy but failed to exhibit any apoptotic response. The results also suggested that apoptosis in these cell lines has a minor requirement for de novo protein synthesis and no requirement for de novo RNA synthesis. This study indicates that although apoptosis can occur during photodynamic therapy-induced cell death, this response is not universal for all cancer cell lines.  相似文献   

18.
The steric factors that allow trivalent [(C(5)Me(5))(3)U] (1) to function as a three-electron reductant with C(8)H(8) to form tetravalent [{(C(5)Me(5))(C(8)H(8))U}(2)(μ-C(8)H(8))] (2) have been explored by examining the synthesis and reactivity of the intermediate, "[(C(5)Me(5))(2)(C(8)H(8))U]" (3), and the slightly less crowded analogues, [(C(5)Me(5))(C(5)Me(4)H)(C(8)H(8))U] and [(C(5)Me(4)H)(2)(C(8)H(8))U], that have, successively one less methyl group. The reaction of [{(C(5)Me(5))(C(8)H(8))U(μ-OTf)}(2)] (4; OTf=OSO(2) CF(3)) with two equivalents of KC(5)Me(5) in THF gave ring-opening to "[(C(5)Me(5))(C(8)H(8))U{O(CH(2))(4)(C(5) Me(5))}]" consistent with in situ formation of 3. Reaction of 4 with two and four equivalents of KC(5)Me(4)H generates two equivalents of [(C(5)Me(5))(C(5)Me(4)H)(C(8)H(8))U] (5) and [(C(5)Me(4)H)(2)(C(8)H(8))U] (6), respectively, which in contrast to 3 were isolable. Tetravalent 5 reduces phenazine and PhEEPh (E=S, Se, and Te) to form the tetravalent uranium reduction products, [{(C(5)Me(5))(C(8)H(8))U}(2)(μ-C(12)H(8)N(2))] (7), [{(C(5)Me(5))(C(8)H(8))U}(2)(μ-SPh)(2)] (8), [{(C(5)Me(5))(C(8)H(8))U}(2)(μ-SePh)(2)] (9), and [{(C(5)Me(5))(C(8)H(8))U}(2)(μ-TePh)(2)] (10), consistent with sterically induced reduction. In contrast, the less sterically crowded 6 does not react with these substrates.  相似文献   

19.
In several recent studies it has been shown that protein kinase C (PKC) activity may either potentiate or antagonize cell killing by different cytotoxic agents. These apparently conflicting observations suggest that the effects of PKC activity on cell survival may depend on the different properties of different cell types but do not exclude the possibility that the effects may also depend on the nature of the cytotoxic agent. In this context the effects of PKC activation and PKC inhibition or down-regulation on Chinese hamster ovary (CHO) cell survival after photodynamic treatment and ionizing radiation were studied. It appeared that PKC activation by short-term incubation with 12-0-tetradecanoyl-phorbol-13-acetate (TPA) protected CHO cells against ionizing radiation but, in contrast, sensitized the cells to photodynamic treatment. Conversely, inhibition of PKC by H7 and down-regulation of PKC activity by prolonged incubation with TPA sensitized CHO cells to ionizing radiation but protected the cells against photodynamic treatment. These results demonstrate that in one particular cell type PKC activity may have opposite effects on cell survival following cellular damage, depending on the nature of the cytotoxic agent .  相似文献   

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