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51.
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53.
The complexation of lanthanide(III) cations with 1,2-propanediaminetetraacetate (1,2-PDTA) in aqueous solution has been investigated by 10Na, 35Cl, 2H and 11O NMR shift measurements. It has been shown that the contact shifts are dominant for 17O, 16Cl and 2H (only for the heavier lanthanide series) and the pseudocontact shifts are dominant for 25Na. It is suggested that the 1,2-PDTA ligand is bound pentadentately via the two nitrogens and the three carboxylates for the lighter lanthanide complexes, hexdentately via the two nitrogens and the four carboxylates for the heavier ones. The numbers of the water coordinated were determined. The small amount of chloride anion in inner coordination sphere was observed. 相似文献
54.
An ortho substituent group has a significant effect on thermal decomposition of aryltriazenes. When the ortho methoxy-substituted phenyltriazenes were treated with methyl iodide at 110-130 °C, 1,5-H shift products were obtained in fair to moderate yields. 相似文献
55.
Y. Z. Song J. M. Xie Y. Song Y. Ye 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2007,81(10):1669-1676
The geometric parameters, vibrational frequencies, and thermochemical values of p-quinonimine (p-AQ) and p-aminophenol (p-AP) were computed ab initio (IIF) and by the density functional theory (DFT) method with the 6-31G(d, p) basis set. Cyclic voltammetry with a golden electrode of p-AP solutions in phosphate buffers at pH 7.30 showed that the standard electrode potential of half reaction for p-QI and p-AP was 0.728 V. The standard electrode potentials of half reactions for p-QI and p-AP were calculated using the free energies and solvation energies of p-QI, p-AP, p-benzoquinone (p-BQ), and hydroquinone (p-HQ). The results showed that the standard electrode potential of half reaction for p-QI and p-AP was 0.743 V at the B3LYP/6-31G(d, p) level and 0.755 V at the HF/6-31G(d, p) level. The standard electrode potentials computed at the B3LYP/6-31G(d, p) and HF/6-31G(d, p) levels were close to their experimental values.
The article is published in the original. 相似文献
56.
叙述了用θ-2θ型X射线衍射仪精确测定电解质溶液结构的新实验技术。设计制作了具有恒温功能的超厚液体样品池,并建立了样品池窗口强度的校正方法。优化了液体X射线衍射数据和结构参数精细化的计算机程序,获得了非常令人满意的实验结果。由θ-2θ型X射线衍射仪精确测定的径向分布函数与θ-θ型衍射仪自由散射比较,表明DRF分辨率有所提高。 相似文献
57.
The Cr-Cr singly-bonded dimers [{η5-RC5H4Cr(CO)3}2] (1, R=Me; 2, R=CO2Et) reacted with an equivalent of elemental selenium in THF at room temperature to give the linear Cr2Se complexes [{η5-RC5H4Cr(CO)2}2Se] (3, R=Me; 4, R=CO2Et), whereas the linear Cr2Se complex (5, R=MeCO) reacted with excess NaBH4, Ph3PCHPh or 2,4-dinitrophenylhydrazine under respective conditions to afford the linear Cr2Se derivatives [{η5-RC5H4Cr(CO)2}2Se] (6, R=MeCH(OH); 7, R=PhCHCMe; 8, R=2,4-(NO2)2C6H3NHNCMe). Similarly, while the butterfly Cr2Se2 complexes [{η5-RC5H4Cr(CO)2}2Se2] (9, R=Me; 10, R=CO2Et) could be produced either by reaction of dimers 1 and 2 with an excess amount of elemental selenium, or by reaction of the linear complexes 3 and 4 with an equivalent of elemental selenium, the butterfly Cr2Se2 derivatives [{η5-RC5H4Cr(CO)2}2Se2] (12, R=MeCH(OH); 13, R=PhCHCMe; 14, R=2,4-(NO2)2C6H3NHNCMe) were yielded by reaction of the butterfly Cr2Se2 complex (11, R=MeCO) with an excess quantity of NaBH4, Ph3PCHPh and 2,4-dinitrophenylhyazine. Both the linear complexes 3, 4, 6-8 and the butterfly complexes 9, 10, 12-14 are new, which have been fully characterized by elemental analysis, spectroscopy and X-ray crystallography. 相似文献
58.
The effects of hydrodynamic interactions on the friction tensors for two particles in solution are studied. The particles have linear dimensions on nanometer scales and are either simple spherical particles interacting with the solvent through repulsive Lennard-Jones forces or are composite cluster particles whose atomic components interact with the solvent through repulsive Lennard-Jones forces. The solvent dynamics is modeled at a mesoscopic level through multiparticle collisions that conserve mass, momentum, and energy. The dependence of the two-particle relative friction tensors on the interparticle separation indicates the importance of hydrodynamic interactions for these nanoparticles. 相似文献
59.
Luo J Zheng QY Chen CF Huang ZT 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(20):5917-5928
A series of inherently chiral calix[4]arenes with cone and partial cone conformations and with crown ether moieties of variable size have been readily synthesized. By taking advantage of the carboxy appendage on the lower rim, these were condensed with the chiral auxiliary (S)-BINOL to form diastereomers which, in most cases, could be separated by preparative TLC, or more desirably, by column chromatography on silica gel (diastereomeric excess >99 % based on HPLC analysis). Seven enantiopure antipodes of inherently chiral calix[4]crowns were obtained after hydrolysis. It has been found that both the size of the crown moiety and alkylation of the last phenolic hydroxy group (accompanied with or without a change in the conformation) affect the separation of the diastereomers. 相似文献
60.
Zi-Shu Yang Yuhang Yao Adam C. Sedgwick Cuicui Li Ye Xia Yan Wang Lei Kang Hongmei Su Bing-Wu Wang Song Gao Jonathan L. Sessler Jun-Long Zhang 《Chemical science》2020,11(31):8204
We report here porphodilactol derivatives and their corresponding metal complexes. These systems show promise as “all-in-one” phototheranostics and are predicated on a design strategy that involves controlling the relationship between intersystem crossing (ISC) and photothermal conversion efficiency following photoexcitation. The requisite balance was achieved by tuning the aromaticity of these porphyrinoid derivatives and forming complexes with one of two lanthanide cations, namely Gd3+ and Lu3+. The net result led to a metalloporphodilactol system, Gd-trans-2, with seemingly optimal ISC efficiency, photothermal conversion efficiency and fluorescence properties, as well as good chemical stability. Encapsulation of Gd-trans-2 within mesoporous silica nanoparticles (MSN) allowed its evaluation for tumour diagnosis and therapy. It was found to be effective as an “all-in-one” phototheranostic that allowed for NIR fluorescence/photoacoustic dual-modal imaging while providing an excellent combined PTT/PDT therapeutic efficacy in vitro and in vivo in 4T1-tumour-bearing mice.We report here porphodilactol derivatives and their corresponding metal complexes as “all-in-one” phototheranostics by controlling the relationship between intersystem crossing (ISC) and photothermal conversion efficiency following photoexcitation. 相似文献