964 resultados para I-3(-)


Relevância:

40.00% 40.00%

Publicador:

Resumo:

Mo(VI) oxo complexes have been persistently sought after as epoxidation catalysts. Further, Mo(V) oxo clusters of the form M4(µ3-X)4 (M = transition metal, X = O, S) have been rigorously studied due to their remarkable structures and also their usefulness as models for electronic studies. The syntheses and characterizations of new Mo(VI) and Mo(V) oxo complexes have been described in this dissertation. Two new complexes MoO2Cl2Ph2P(O)CH2COOH and MoO2Cl2Ph2P(O)C6H4tBuS(O) were synthesized from reactions of “MoO2Cl2” with ligands Ph2P(O)CH2COOH and Ph2P(O)C6H4tBuS(O). Tetrameric packing arrangements comprised of hydrogen bonds were obtained for the complex MoO2Cl2Ph2P(O)CH2COOH and the ligand Ph2P(O)CH2COOH. Further the stability of an Mo-O bond was preferred over the Mo-S bond even though this resulted in the formation of a more strained seven membered ring. Tetranuclear Mo(V) complexes of the form [Mo4(µ3-O)4(µ-O2PR2)4O4], (PR2 = PPh2, PMe2) were synthesized using reactions of MoO2(acac)2 with diphenyl and dimethyl phosphinic acids, in ethanol. In the crystal structure of these complexes four Mo=O units are interconnected by four triply bridging oxygen atoms and bridging phosphinate ligands. The complex exhibited fourfold symmetry as evidenced by a single 31P NMR peak for the P atoms in the coordinated ligands. Reaction of WO2(acac)2 with Ph2POOH in methanol resulted in a dimeric W(VI) complex [(CH3O)2(O)W(µ-O)( µ-O2PPh2)2W(O)(CH3O)2] which contained a packing disorder in its crystal structure. Similar reactions of MoO2(acac)2 with benzoic acid derivatives resulted in dimeric complexes of the form [Mo2O2(acac)2(µ-O)(µ-OC2H5)(µ-O2CR)] (R = C6H5, (o-OH)C6H4, (p-Cl)C6H4, (2,4-(OH)2)C6H3, (o-I)C6H4) and one tetrameric complex [Mo2O2(acac)2(µ-O)(µ-OC2H5)(µ-O2C)C6H4(p-µ-O2C)Mo2O2(acac)2(µ-O)(µ-OC2H5)] with terephthalic acid. 1H NMR proved very useful in the prediction of the formation of dimers with the substituted benzoic acids, which were also confirmed by elemental analyses. The reductive capability of ethanol proved instrumental in the syntheses of Mo(V) tetrameric and dimeric clusters. Synthetic details, IR, 1H and 31P NMR spectroscopy and elemental analyses are reported for all new complexes. Further, single crystal X-ray structures of MoO2Cl2Ph2P(O)CH2COOH, MoO2Cl2Ph2P(O)C6H4tBuS(O), [Mo4(µ3-O)4(µ-O2PR2)4O4], (PR2 = PPh2, PMe2), [(CH3O)2(O)W(µ-O)( µ-O2PPh2)2W(O)(CH3O)2] and [Mo2O2(acac)2(µ-O)(µ-OC2H5)(µ-O2CR)] (R = C6H5, (o-OH)C6H4) are also presented.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Export of mRNA from the nucleus is linked to proper processing and packaging into ribonucleoprotein complexes. Although several observations indicate a coupling between mRNA 3' end formation and export, it is not known how these two processes are mechanistically connected. Here, we show that a subunit of the mammalian pre-mRNA 3' end processing complex, CF I(m)68, stimulates mRNA export. CF I(m)68 shuttles between the nucleus and the cytoplasm in a transcription-dependent manner and interacts with the mRNA export receptor NXF1/TAP. Consistent with the idea that CF I(m)68 may act as a novel adaptor for NXF1/TAP, we show that CF I(m)68 promotes the export of a reporter mRNA as well as of endogenous mRNAs, whereas silencing by RNAi results in the accumulation of mRNAs in the nucleus. Moreover, CF I(m)68 associates with 80S ribosomes but not polysomes, suggesting that it is part of the mRNP that is remodeled in the cytoplasm during the initial stages of translation. These results reveal a novel function for the pre-mRNA 3' end processing factor CF I(m)68 in mRNA export.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

composed by A. Kaiser

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Boberach: Ein jüdischer Einwohner Frankfurts, dem nach einem Aufenthalt von 21 Jahren zunächst das Frankfurter Bürgerrecht in Aussicht gestellt worden war, beschwert sich darüber, daß er wegen seines Auftretens in Volksversammlungen verhaftet und ausgewiesen wurde und verlangt ein Gerichtsverfahren oder Genugtuung, nachdem er sich um Schutz durch seine württembergische Heimatbehörde bemüht hat

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Vorbesitzer: Dominikanerkloster Frankfurt am Main

Relevância:

40.00% 40.00%

Publicador:

Resumo:

33 Briefe zwischen Julius S. Bach und Max Horkheimer, 1937-1941; 1 Brief von Julius S. Bach an Mary von Meldelsohn, 28.08.1940; 24 Briefe zwischen Richard Bach und Max Horkheimer, 1938-1940; 1 Abschrift eines Briefes von Oscar W. Gross an Emil de Leuw, 1938; 1 Brief von A. Bailer an Mr. Iggersheimer, 01.05.1940; 1 Brief von Max Horkheimer an Bailliere, Tindall & Cox London, 05.07.1949; 1 Brief von Beatrix Baird an Max Horkheimer; 5 Briefe zwischen Leonard Balet und Max Horkheimer, 1938-1949; 2 Briefe zwischen John Simon Guggenheim Memorial Foundation New York und Max Horkheimer, 22.11.1948, 05.01.1949; 1 Brief von W. H. de Graaff, Ladislaus Bálint an Max Horkheimer, 11.05.1938; 6 Briefe zwischen Bank of Manhattan Company New York und Max Horkheimer, 1934-1935; 6 Briefe zwischen Ladislaus Bálint und Max Horkheimer, 1934-1935; 2 Briefe zwischen der Bank of the Manhatten Company in New York und Max Horkheimer, 14./15.11.1934; 5 Briefe zwischen der Bankers Trust Company und Max Horkheimer, 1934; 1 Brief von R. Bárány an Max Horkheimer, 05.05.1933; 5 Briefe zwischen Hans Baron und Max Horkheimer, 1936; 3 Briefe zwischen Salo W. Baron und Max Horkheimer, 1941-1942, 16.04.1940; 1 Brief zwischen A. Barratt Brown und Max Horkheimer, 01.10.1936;