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41.
Peter Jutzi Andreas Klipp Andreas Mix Beate Neumann Hans-Georg Stammler 《Silicon Chemistry》2007,3(3-4):151-156
Reaction of pentamethylcyclopentadienyl(pentachloro)disilane (2), prepared from hexachlorodisilane and potassium pentamethylcyclopentadienide
(Cp*K), with a further equivalent of Cp*K leads selectively to the title compound Cp*
2
Si
2
Cl
4 (3) which was characterized by NMR and X-ray structural data. Dehalogenation of 3 with four equivalents of sodium naphthalenide
offers an alternative route for the synthesis of decamethylsilicocene (1).
Dedicated to Professor Mitsuo Kira on the occasion of being honoured with the Wacker Silicon Award 2005. 相似文献
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Rancan F Wiehe A Nöbel M Senge MO Omari SA Böhm F John M Röder B 《Journal of photochemistry and photobiology. B, Biology》2005,78(1):17-28
The search for new efficient sensitizers for photodynamic therapy (PDT) points to improve photophysical properties like absorption in the red region and singlet oxygen quantum yield as well as to control the localization of the sensitizer within the tumour cell. Depending on their physicochemical properties and their uptake mechanism, sensitizers can reach different intracellular concentrations and localize in different subcellular compartments. Moreover, the preferential localization of a sensitizer in target organelles, like mitochondria or lysosomes, could determine the cell death mechanism after PDT. This study aimed to investigate the influence of substitutions on dihydroxychlorins with regard to intracellular uptake, subcellular localization and cell death pathway. Moreover, the effect of a liposome-based delivery system was tested. The intracellular uptake was found to be strictly dependent on the sensitizer molecular structure and the means of its delivery. The most polar sensitizer in this study (compound 3) had, depending on incubation time, an intracellular concentration 2-8 times higher than the unsubstituted chlorin 1. All investigated photosensitizers localize predominantly in lysosomes but after longer incubation times weak fluorescence intensity was also detected in mitochondria and Golgi apparatus. The cell death pathway was found to be influenced by the sensitizer intracellular concentration and the applied light doses. In general, the increasing amphiphilicity of the sensitizer molecules is correlated with an increased sensitizer uptake and an increased rate of necrotic cells after irradiation. 相似文献
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48.
Falk Ebeler Dr. Yury V. Vishnevskiy Beate Neumann Dr. Hans-Georg Stammler Priv.-Doz. Dr. Rajendra S. Ghadwal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(31):e202200739
Mesoionic dithiolates [(MIDtAr)Li(LiBr)2(THF)3] (MIDtAr={SC(NDipp)}2CAr; Dipp=2,6-iPr2C6H3; Ar=Ph 3 a , 3-MeC6H4 (3-Tol) 3 b , 4-Me2NC6H4 (DMP) 3 c ) and [(MIDtPh)Li(THF)2] ( 4 ) are readily accessible (in≥90 % yields) as crystalline solids on treatments of anionic dicarbenes Li(ADCAr) ( 2 a - c ) (ADCAr={C(NDipp)2}2CAr) with elemental sulfur. 3 a - c and 4 are monoanionic ditopic ligands with both the sulfur atoms formally negatively charged, while the 1,3-imidazole unit bears a formal positive charge. Treatment of 4 with (L)GeCl2 (L=1,4-dioxane) affords the germylene (MIDtPh)GeCl ( 5 ) featuring a three-coordinated Ge atom. 5 reacts with (L)GeCl2 to give the Ge−Ge catenation product (MIDtPh)GeGeCl3 ( 6 ). KC8 reduction of 5 yields the homoleptic germylene (MIDtPh)2Ge ( 7 ). Compounds 3 a - c and 4 – 7 have been characterized by spectroscopic studies and single-crystal X-ray diffraction. The electronic structures of 4 – 7 have been analyzed by DFT calculations. 相似文献
49.
Christian Balischewski Dr. Biswajit Bhattacharyya Dr. Eric Sperlich Dr. Christina Günter Alkit Beqiraj Prof. Dr. Tillmann Klamroth Dr. Karsten Behrens Stefan Mies Alexandra Kelling Susanne Lubahn Lea Holtzheimer Anne Nitschke Prof. Dr. Andreas Taubert 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(64):e202201068
Fifteen N-butylpyridinium salts – five monometallic [C4Py]2[MBr4] and ten bimetallic [C4Py]2[M0.5aM0.5bBr4] (M=Co, Cu, Mn, Ni, Zn) – were synthesized, and their structures and thermal and electrochemical properties were studied. All the compounds are ionic liquids (ILs) with melting points between 64 and 101 °C. Powder and single-crystal X-ray diffraction show that all ILs are isostructural. The electrochemical stability windows of the ILs are between 2 and 3 V. The conductivities at room temperature are between 10−5 and 10−6 S cm−1. At elevated temperatures, the conductivities reach up to 10−4 S cm−1 at 70 °C. The structures and properties of the current bromide-based ILs were also compared with those of previous examples using chloride ligands, which illustrated differences and similarities between the two groups of ILs. 相似文献
50.
The synthesis of glycopeptides carrying tumour-associated antigens is of interest for cancer diagnosis and treatment. Here, a very efficient route lo disaccharide threonine building block 8 is presented which allows the introduction of the sialyl-Tn antigen into a peptide. The syntheses of the undecapeptide and the sialyl-Tn-containing glycoundecapeptide, which are a part of the repeating unit of MUC1, were performed by solid-phase synthesis with an allylic anchor cleavable under neutral conditions. After detachment from the resin, the peptide and the glycopeptide arc completely deprotected giving the target compounds 13 and 15 , respectively. 相似文献