Publications by authors named "Roman Geier"

In this contribution a convenient synthetic method to obtain tetraacylgermanes Ge[C(O)R] (R=mesityl (1 a), phenyl (1 b)), a previously unknown class of highly efficient Ge-based photoinitiators, is described. Tetraacylgermanes are easily accessible via a one-pot synthetic protocol in >85 % yield, as confirmed by NMR spectroscopy, mass spectrometry, and X-ray crystallography. The efficiency of 1 a,b as photoinitiators is demonstrated in photobleaching (UV/Vis), time-resolved EPR (CIDEP), and NMR/CIDNP investigations as well as by photo-DSC studies.

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The synthesis of redox-active p- and o-quinones 2-phenylamino-4-phenylimino[6]helicene-1-one 1, 2-phenylamino[6]-helicene-1,4-dione 2, and 4-phenyl[6]helicene-1,2-dione 3 in their enantiopure forms by post-functionalization of (P)- and (M)-1,2-dimethoxy[6]helicene is presented. Structural characterization in solution and in the solid state was accomplished by 2D NMR spectroscopy methods and X-ray diffraction analysis, respectively. Interpretation of electrochemical redox data was accompanied by a detailed orbital picture, derived from DFT calculations.

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In this study, we demonstrate that emulsified microemulsions and micellar cubosomes are suitable as sustained delivery vehicles for water-soluble proteins. Through structural modifications, the loading efficiency of two model proteins, namely bovine serum albumin (BSA) and cytochrome c could be remarkably increased. A procedure for preparing these particles loaded with optimized amounts of sensitive substances is presented.

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