Zur struktur des diethylgermanium-diphenylsiliciumoxids und zur konformation von achtringen mit silicium und germanium

Diethylgermanium-diphenylsilicon oxide [(Et₂Ge)O(Ph₂Si)O]₂ has been prepared by reaction of diethylgermanium dichloride and diphenyldihydroxysilane. Spectra and X-ray analysis showed the presence of a puckered eight-membered silicon—germanium—oxygen ring. The ethyl groups of the germanium atoms are disordered. A procedure is proposed for eight-membered rings with low symmetry to obtain a classification into clearly explaining ring forms based on exact or approximated planes put through as many ring atoms as possible. All of the 42 published eight-membered rings with silicon or germanium and oxygen, nitrogen or carbon could be classified by this method.     

Synthesis and characterization, novel across adjacent ring formed phthalocyanine

Novel mononuclear Zn(ii) 4, Co(ii) 5 and Cu(ii) 6 metallophthalocyanines have been synthesized from 4,4'(ethane-1,1-p-phenol-2,2-p-phenoxy)phthalonitrile 3, which can be obtained by the reaction of 4-nitrophthalonitrile 1 with 1,1,2,2-tetrakis(p-hydroxy-phenyl)-ethane 2. The target water-soluble derivatives of 7-9 were acquired from a boiling suspension of the compounds in aqueous 20% KOH solution. The synthesized complexes have been characterized by UV-vis, IR, (1)H NMR and MALDI-TOF-mass spectroscopies. In addition, the geometric and electronic structures of 2-6 were investigated by ab initio/DFT quantum mechanical calculations using the Gaussian 03 program with HF theory at the B3LYP/3-21G level. The redox properties of the complexes 4-6 were examined by cyclic voltammetry on platinum in DMSO/TBAP. These complexes displayed one-electron metallophthalocyanine-based and multi-electron hydroxyphenyl-based redox processes. The effect of temperature on the d.c. conductivity and impedance spectra of spin coated films of compounds were investigated at the temperatures between 300-452 K and in the frequency range of 40-105 Hz. Thermally activated conductivity dependence on temperature was observed for all compounds. A.c. results indicated that conduction mechanism can be explained by classical hopping barriers mechanism for all films.     

Indonesian propolis: chemical composition, biological activity and botanical origin

From a biologically active extract of Indonesian propolis from East Java, 11 compounds were isolated and identified: four alk(en)ylresorcinols (obtained as an inseparable mixture) (1-4) were isolated for the first time from propolis, along with four prenylflavanones (6-9) and three cycloartane-type triterpenes (5, 10 and 11). The structures of the components were elucidated based on their spectral properties. All prenylflavanones demonstrated significant radical scavenging activity against diphenylpicrylhydrazyl radicals, and compound 6 showed significant antibacterial activity against Staphylococcus aureus. For the first time Macaranga tanarius L. and Mangifera indica L. are shown as plant sources of Indonesian propolis.     

The Chemical Scaffold of Theranostic Radiopharmaceuticals: Radionuclide,Bifunctional Chelator,and Pharmacokinetics Modifying Linker

Therapeutic radiopharmaceuticals have been researched extensively in the last decade as a result of the growing research interest in personalized medicine to improve diagnostic accuracy and intensify intensive therapy while limiting side effects. Radiometal-based drugs are of substantial interest because of their greater versatility for clinical translation compared to non-metal radionuclides. This paper comprehensively discusses various components commonly used as chemical scaffolds to build radiopharmaceutical agents, i.e., radionuclides, pharmacokinetic-modifying linkers, and chelators, whose characteristics are explained and can be used as a guide for the researcher.