TY - JOUR A1 - Poppenberg, J. A1 - Richter, S. A1 - Traulsen, Ch. H.-H. A1 - Darlatt, Erik A1 - Baytekin, B. A1 - Heinrich, Thomas A1 - Deutinger, P. M. A1 - Huth, K. A1 - Unger, Wolfgang A1 - Schalley, Ch. T1 - Programmable multilayers of nanometer-sized macrocycles on solid support and stimuli-controlled on-surface pseudorotaxane formation N2 - Mechanically interlocked molecules (MIMs) such as rotaxanes and catenanes are capable of mechanical motion on the nanoscale and are therefore promising prototypes for molecular machines in recent nanotechnology. However, most of the existing examples are isotropically distributed in solution, which prohibits concerted movement and with it the generation of macroscopic effects. Thus, arranging them in ordered arrays is of huge interest in recent research. We report the deposition of quite densely packed multilayers of tetralactam macrocycles on gold surfaces by metal-coordinated layer-by-layer self-assembly. Linear dichroism effects in angle-resolved NEXAFS spectra indicate a preferential orientation of the macrocycles. The sequence of the metal ions can be programmed by the use of different transition metal ions at each deposition step. Additionally, reversible on-surface pseudorotaxane formation was successfully realized by repeated uptake and release of axle molecules inside the macrocycles cavities. KW - NEXAFS KW - XPS KW - Supramolecular Chemistry KW - Multilayers KW - Pyridine KW - UV/Vis KW - Macrocycles KW - Pseudorotaxanes PY - 2013 DO - https://doi.org/10.1039/c3sc50558h VL - 4 IS - 8 SP - 3131 EP - 3139 AN - OPUS4-42668 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, S. A1 - Traulsen, C. H.-H. A1 - Heinrich, Thomas A1 - Poppenberg, J. A1 - Leppich, C. A1 - Holzweber, Markus A1 - Unger, Wolfgang A1 - Schalley, C.A. T1 - Sequence-programmable multicomponent multilayers of nanometer-sized tetralactam macrocycles on gold surfaces N2 - Multicomponent multilayers have been deposited on gold surfaces by metal-ion-mediated layer-by-layer self-assembly of differently functionalized tetralactam macrocycles. The layer stack can be programmed with respect to the sequences of metal ions and macrocycles by the deposition sequence. KW - Organic layer KW - XPS KW - SIMS KW - NEXAFS PY - 2013 DO - https://doi.org/10.1021/jp405492v SN - 1932-7447 SN - 1089-5639 VL - 117 IS - 37 SP - 18980 EP - 18985 PB - Soc. CY - Washington, DC AN - OPUS4-32576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Unger, Wolfgang T1 - Metrology for Nano-Analysis: Establishing Reference Methods for Characterizing Nano-Materials T2 - Workshop on Advanced Characterization of Nanomaterials CY - Zaragoza, Spain DA - 2013-09-19 PY - 2013 AN - OPUS4-29865 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Unger, Wolfgang T1 - Der FB "Oberflächenanalytik und Grenzflächenchemie" der BAM: Referenzmaterialien für die Nanoanalytik und ausgewählte Beispiele angewandter Forschung T2 - TU Berlin , Institut für Optik und Atomare Physik, AG Kannengießer, Wintersemester 2013/2014, Forschungsseminar "Moderne analytische Methoden der Physik" CY - Berlin, Germany DA - 2013-10-29 PY - 2013 AN - OPUS4-29870 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Unger, Wolfgang T1 - Metrology for Surface Chemical Analysis: Status and Challenges T2 - ECASIA 2013 CY - Cagliari, Italy DA - 2013-10-14 PY - 2013 AN - OPUS4-29873 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Unger, Wolfgang T1 - The Activities of the CCQM Surface Analysis Working Group (SAWG) - Achievements and Challenges in Metrology in Surface and Thin Film Analysis T2 - EURAMET TC-MC Plenary Meeting CY - Braunschweig, Germany DA - 2013-02-07 PY - 2013 AN - OPUS4-27656 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senoner, Mathias A1 - Unger, Wolfgang T1 - Summary of ISO/TC 201 technical report: ISO/TR 19319:2013 - Surface chemical analysis - Fundamental approaches to determination of lateral resolution and sharpness in beam-based methods N2 - This Technical Report revises ISO/TR 19319:2003 - Surface chemical Analysis-Auger electron spectroscopy and X-ray photoelectron spectroscopy-Determination of lateral resolution, analysis area and sample area viewed by the analyser. The revised Technical Report gives a short introduction to basic models of image formation and introduces functions which characterize the performance of imaging instruments with respect to lateral resolution and sharpness. The determination of lateral resolution by imaging of square-wave gratings and the determination of sharpness by imaging of narrow stripes and straight edges are described in detail. Finally, physical factors affecting lateral resolution, analysis area and sample area viewed by the analyser are discussed. KW - CTF KW - ESF KW - Lateral resolution KW - LSF KW - MTF KW - Narrow stripe KW - Noise KW - PSF KW - Resolution criterion KW - Sharpness KW - Square-wave grating KW - Straight edge PY - 2013 DO - https://doi.org/10.1002/sia.5294 SN - 0142-2421 SN - 1096-9918 VL - 45 IS - 9 SP - 1313 EP - 1316 PB - Wiley CY - Chichester AN - OPUS4-29012 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Girard-Lauriault, P.-L. A1 - Dietrich, Paul A1 - Gross, Thomas A1 - Wirth, Thomas A1 - Unger, Wolfgang T1 - Chemical characterization of the long-term ageing of nitrogen-rich plasma polymer films under various ambient conditions N2 - Nitrogen rich plasma polymer films (L-PPE:N) were prepared by low-pressure RF plasma using a 1:1 mixture of ethylene and ammonia and aged for 345 d in four different ambient conditions: (i) at room temperature (RT) in air; (ii) at RT in nitrogen; (iii) at -20?°C in air and; (iv) at –20 °C in nitrogen. The films were analyzed by X-ray photoelectron spectroscopy (XPS) and by time-of-flight secondary ion mass spectrometry (ToF-SIMS) at various intervals over the duration of the experiment. The ageing of primary amines, NH2, was followed by chemical derivatization with 4-trifluoromethyl benzaldehyde. Storage at –20 °C, mostly independently of ambient atmosphere, slowed down ageing to almost undetectable levels as evaluated by the analytical methods used for this study. KW - Ageing KW - Plasma polymers KW - Primary amines KW - ToF-SIMS KW - XPS PY - 2013 DO - https://doi.org/10.1002/ppap.201200118 SN - 1612-8850 SN - 1612-8869 VL - 10 IS - 4 SP - 388 EP - 395 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-28006 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lippitz, Andreas A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang T1 - Plasma bromination of HOPG surfaces: a NEXAFS and synchrotron XPS study N2 - Br bonding on plasma brominated graphite surfaces has been studied by using Near Edge X-ray Absorption Fine Structure (NEXAFS) and X-ray Photoelectron Spectroscopy (XPS). Br2 and bromoform were used as plasma gases in an r.f. cw low pressure plasma process. Kr plasma had been used to study separately the physical and chemical plasma etching effects. At early steps of plasma bromination which lead to only small XPS Br surface concentration values a quick decay of aromaticity has been observed. At low Br surface concentration radical or even electrophilic addition of bromine onto sp2 carbon atoms is discussed as the dominating reaction pathway. At higher Br surface concentrations the inherent formation of sp3 defects in the graphene network by chemical etching processes promotes nucleophilic substitution of bromine at sp3 carbons as a competing reaction pathway. Both reaction pathways lead to C–Br species characterized by the same Br 3d XPS binding energy. However more than one Br 3d component in XP spectra has been found at lower Br2 plasma induced Br surface concentrations and complexation of bromine at HOPG is assumed as a third way of interaction with Br2 plasma. KW - HOPG KW - Graphite KW - Plasma bromination KW - Low pressure plasma KW - NEXAFS KW - XPS PY - 2013 DO - https://doi.org/10.1016/j.susc.2013.01.020 SN - 0039-6028 VL - 611 SP - L1 EP - L7 PB - Elsevier CY - Amsterdam AN - OPUS4-27928 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Unger, Wolfgang T1 - Imaging SIMS: Status and selected applications at BAM T2 - DGMS Workshop "Imaging MS" CY - Berlin, Germany DA - 2013-03-10 PY - 2013 AN - OPUS4-28044 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -