0000000000593922
AUTHOR
Beate Müller
MALDI-TOF characterization of macromonomers
Methacryloyl endfunctionalized oligostyrene macromonomers were characterized by matrix assisted laser desorption ionization/time of flight (MALDI-TOF) spectroscopy and by isocratic and gradient high performance liquid chromatography (HPLC). The molar mass distribution derived by the different techniques coincide for the investigated oligomers. Mixing experiments revealed that the MALDI-TOF peak areas do not necessarily represent the mixing ratio of the components. Combination of gradient HPLC and MALDI-TOF has resolved the chemical composition of the coupling products formed by reaction of the living anion with oxygen.
From Hexaphenylbenzene to 1,2,3,4,5,6-Hexacyclohexylcyclohexane
The hydrogenation of hexaphenylbenzene was studied, affording novel partially hydrogenated hexacyclohexylbenzene (HCB) as well as fully hydrogenated 1,2,3,4,5,6-hexacyclohexylcyclohexane (HCC) as an unprecedented “oligocyclohexyl” molecule. The reaction process was analyzed by mass spectrometry with atmospheric pressure chemical ionization and high-performance liquid chromatography. From a crude product mixture, two different crystals with flake- and block-shapes could be grown and analyzed by X-ray crystallography, revealing their structures as HCB and HCC. While a geared arrangement of cyclohexyl substitutes was found in HCB, two isomeric structures were identified in HCC crystal with cha…
Quantification of fluorescent dyes in organ tissue samples via HPLC analysis
Abstract The determination of regional blood flow via the accumulation of fluorescent microspheres is a concept regularly used in medical research. Typically, the microbeads get extracted from the tissue of interest and are then quantified by measuring the absorption or fluorescence of the incorporated dyes without further separation from the medium. However, in that case the absorption spectra of different dyes can overlap when used simultaneously, leading to an overestimation of the concentration. Additionally, background absorption from the medium can be problematic. Therefore, a high performance liquid chromatography method for the simultaneous detection of four dyes (orange, crimson, y…
Synthesis of Nonplanar Graphene Nanoribbon with Fjord Edges
As a new family of semiconductors, graphene nanoribbons (GNRs), nanometer-wide strips of graphene, have appeared as promising candidates for next-generation nanoelectronics. Out-of-plane deformation of π-frames in GNRs brings further opportunities for optical and electronic property tuning. Here we demonstrate a novel fjord-edged GNR (FGNR) with a nonplanar geometry obtained by regioselective cyclodehydrogenation. Triphenanthro-fused teropyrene 1 and pentaphenanthro-fused quateropyrene 2 were synthesized as model compounds, and single-crystal X-ray analysis revealed their helically twisted conformations arising from the [5]helicene substructures. The structures and photophysical properties …
CCDC 2000869: Experimental Crystal Structure Determination
Related Article: Marcel Dillenburger, Zijie Qiu, Cheng-Wei Ju, Beate Müller, Svenja Morsbach, Dieter Schollmeyer, Akimitsu Narita, Klaus Müllen|2020|J.Am.Chem.Soc.|142|12916|doi:10.1021/jacs.0c04956
CCDC 2000868: Experimental Crystal Structure Determination
Related Article: Marcel Dillenburger, Zijie Qiu, Cheng-Wei Ju, Beate Müller, Svenja Morsbach, Dieter Schollmeyer, Akimitsu Narita, Klaus Müllen|2020|J.Am.Chem.Soc.|142|12916|doi:10.1021/jacs.0c04956