Dr. Hans-Joachim Räder

project leader, mass spectrometry


Max Planck Institute for Polymer Research
Ackermannweg 10
D-55128 Mainz, Germany
(+49) 6131-379-311 (phone)
(+49) 6131-379-100 (fax)
raeder@mpip-mainz.mpg.de

research topics

• Soft Landing Mass Spectrometry
• Pulsed Laser Deposition
• Electrical Field Alignment

Soft Landing and Pulsed Laser Deposition for Thin Films

Thin films are important in various applications, such as corrosion protection, surface compatibilization or molecular electronics. Traditional methods for thin film preparation require samples which can be processed either from solution or from the gas phase, therefore suitable molecules must be soluble or volatile. Large molecules like Polycyclic Aromatic Hydrocarbons (PAHs), however, are neither soluble nor volatile. PAHs can be regarded as well defined segments of graphite, thus rendering them interesting candidates for electronic applications especially with increasing size. Therefore we developed new processing techniques, which overcome the existing limitations: Matrix Assisted Laser Desorption/Ionization - Soft Landing (MALDI-SL) and Pulsed Laser Deposition (PLD). Both methods allow to “evaporate” huge molecules much beyond their thermal evaporation limit and in both cases, the phase transition from the solid state to the gas phase is achieved with the help of a Nitrogen Laser.

Soft Landing (Fig. 1) makes use of a modified sectorfield mass spectrometer and a special method of MALDI sample preparation for insoluble molecules developed by us. MALDI-SL enables not only the intact phase transition and ionization of molecules, so far considered as intractable, but also their direct purification due to their mass-to-charge ratio. Furthermore, MALDI-SL has virtually no upper molecular weight limit. So far crystalline 2 D structures on top of Highly Oriented Pyrolytic Graphite (HOPG) could be prepared and characterized by Scanning Tunneling Microscopy (STM) with PAHs like Hexabenzocoronene (C42, HBC) being at the borderline of solubility and volatility and the Superphenalene (C96) being well above the conventional processing limits.

As opposed to MALDI-SL which handles the non-volatile and insoluble molecules in form of their ions, Pulsed Laser Deposition employs the neutral molecules in the gas phase, produced by direct absorption of laser light (Fig. 2). With optimized experimental parameters, the size of applicable molecules for PLD is much higher than the thermal decomposition limit. Figure 2 shows the STM picture of a triangular PAH molecule (C60) with sub molecular resolution which could not be obtained by traditional sample preparation methods for STM. Hitherto PAH molecules with up to 222 carbon atoms could be deposited successfully.

group members

> Nataliya Mavrinskaya (PhD Student)
> Anna Cristadoro (PhD Student)
> Dr. Mainak Roy (Post Doc)
> Ali Rouhanipour (Engineer)
> Stefan Türk (Engineer)

former goup members:

> Dr. Xinli Yang
> Dr. Sarah Trimpin
> Dr. Laurence Przybilla (before Laurence Goix)
> Kimihiro Yoshimura
> Sabine Kummer
> Simone Junker
> Dr. Kai Martin
> Dr. Jochen Spickermann

publications

1.          Yang, X. Y.; Dou, X.; Rouhanipour, A.; Zhi, L. J.; Rader, H. J.; Mullen, K., Two-dimensional graphene nanoribbons. Journal of the American Chemical Society 2008, 130, (13), 4216-+.
2.         Tsao, H. N.; Rader, H. J.; Pisula, W.; Rouhanipour, A.; Mullen, K., Novel organic semiconductors and processing techniques for organic field-effect transistors. Physica Status Solidi a-Applications and Materials Science 2008, 205, (3), 421-429.
3.         Glowatzki, H.; Gavrila, G. N.; Seifert, S.; Johnson, R. L.; Rader, J.; Mullen, K.; Zahn, D. R. T.; Rabe, J. P.; Koch, N., Hexa-peri-hexabenzocoronene on Ag(111): Monolayer/multilayer transition of molecular orientation and electronic structure. Journal of Physical Chemistry C 2008, 112, (5), 1570-1574.
4.         Glowatzki, H.; Gavrila, G. N.; Seifert, S.; Johnson, R. L.; Rader, J.; Mullen, K.; Zahn, D. R. T.; Rabe, J. P.; Koch, N., Hexa-peri-hexabenzocoronene on Ag(111): Monolayer/multilayer transition of molecular orientation and electronic structure. Journal of Physical Chemistry C 2008, 112, 1570-1574.
5.         Cristadoro, A.; Ai, M.; Rader, H. J.; Rabe, J. P.; Mullen, K., Electrical field-induced alignment of nonpolar hexabenzocoronene molecules into columnar structures on highly oriented pyrolitic graphite investigated by STM and SFM. Journal of Physical Chemistry C 2008, 112, (14), 5563-5566.
6.         Cristadoro, A.; Lieser, G.; Rader, H. J.; Mullen, K., Field-force alignment of disc-type pi systems. Chemphyschem 2007, 8, (4), 586-591.
7.         Trimpin, S.; Rader, H. J.; Mullen, K., Investigations of theoretical principles for MALDI-MS derived from solvent-free sample preparation - Part I. Preorganization. International Journal of Mass Spectrometry 2006, 253, (1-2), 13-21.
8.         Trimpin, S.; Keune, S.; Rader, H. J.; Mullen, K., Solvent-free MALDI-MS: Developmental improvements in the reliability and the potential of MALDI in the analysis of synthetic polymers and giant organic molecules. Journal of the American Society for Mass Spectrometry 2006, 17, (5), 661-671.
9.         Rader, H. J.; Rouhanipour, A.; Talarico, A. M.; Palermo, V.; Samori, P.; Mullen, K., Processing of giant graphene molecules by soft-landing mass spectrometry. Nature Materials 2006, 5, (4), 276-280.
10.      Rader, H. J.; Mullen, K., Soft landing of rapid ions. Nachrichten Aus Der Chemie 2006, 54, (7), 746-750.
11.      Jung, S. H.; Pisula, W.; Rouhanipour, A.; Rader, H. J.; Jacob, J.; Mullen, K., A conjugated polycarbazole ring around a porphyrin. Angewandte Chemie-International Edition 2006, 45, (28), 4685-4690.
12.      Yang, X.; Rader, H. J.; Rouhanipour, A.; Mullen, K., Soft deposition of organic macromolecules with fast atom bombardment mass spectrometry. European Journal of Mass Spectrometry 2005, 11, (3), 287-293.
13.      Simpson, C. D.; Mattersteig, G.; Martin, K.; Gherghel, L.; Bauer, R. E.; Rader, H. J.; Mullen, K., Nanosized molecular propellers by cyclodehydrogenation of polyphenylene dendrimers. Journal of the American Chemical Society 2004, 126, (10), 3139-3147.
14.      Cho, B. K.; Jain, A.; Nieberle, J.; Mahajan, S.; Wiesner, U.; Gruner, S. M.; Turk, S.; Rader, H. J., Synthesis and self-assembly of amphiphilic dendrimers based on aliphatic polyether-type dendritic cores. Macromolecules 2004, 37, 4227-4234.
15.      Laine, O.; Trimpin, S.; Rader, H. J.; Mullen, K., Changes in post-source decay fragmentation behavior of poly(methyl methacrylate) polymers with increasing molecular weight studied by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. European Journal of Mass Spectrometry 2003, 9, (3), 195-201.
16.      Trimpin, S.; Grimsdale, A. C.; Rader, H. J.; Mullen, K., Characterization of an insoluble poly(9,9-diphenyl-2,7-fluorene) by solvent-free sample preparation for MALDI-TOF mass spectrometry. Analytical Chemistry 2002, 74, (15), 3777-3782.
17.      Simpson, C. D.; Brand, J. D.; Berresheim, A. J.; Przybilla, L.; Rader, H. J.; Mullen, K., Synthesis of a giant 222 carbon graphite sheet. Chemistry-a European Journal 2002, 8, (6), 1424-1429.
18.      Kricheldorf, H. R.; Langanke, D.; Stricker, A.; Rader, H. J., Polylactones, 53 - Formation of cyclic polyesters in the combined ringexpansion polymerization/ring-opening polycondensation of lactones. Macromolecular Chemistry and Physics 2002, 203, (2), 405-412.
19.      Gherghel, L.; Kubel, C.; Lieser, G.; Rader, H. J.; Mullen, K., Pyrolysis in the mesophase: A chemist's approach toward preparing carbon nano- and microparticles. Journal of the American Chemical Society 2002, 124, (44), 13130-13138.
20.      Yoshimura, K.; Przybilla, L.; Ito, S. J.; Brand, J. D.; Wehmeir, M.; Rader, H. J.; Mullen, K., Characterization of large synthetic polycyclic aromatic hydrocarbons by MALDI- and LD-TOF mass spectrometry. Macromolecular Chemistry and Physics 2001, 202, (2), 215-222.
21.      Trimpin, S.; Rouhanipour, A.; Az, R.; Rader, H. J.; Mullen, K., New aspects in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: a universal solvent-free sample preparation. Rapid Communications in Mass Spectrometry 2001, 15, (15), 1364-1373.
22.      Trimpin, S.; Eichhorn, P.; Rader, H. J.; Mullen, K.; Knepper, T. P., Recalcitrance of poly(vinylpyrrolidone): evidence through matrix-assisted laser desorption-ionization time-of-flight mass spectrometry. Journal of Chromatography A 2001, 938, (1-2), 67-77.
23.      Przybilla, L.; Francke, V.; Rader, H. J.; Mullen, K., Block length determination of a poly(ethylene oxide)-b-poly(p-phenylene ethynylene) diblock copolymer by means of MALDI-TOF mass spectrometry combined with fragment-ion analysis. Macromolecules 2001, 34, (13), 4401-4405.
24.      Leuninger, J.; Trimpin, S.; Rader, H. J.; Mullen, K., Novel approach to ladder-type polymers: Polydithiathianthrene via the intramolecular acid-induced cyclization of methylsulfinyl-substituted poly (meta-phenylene sulfide). Macromolecular Chemistry and Physics 2001, 202, (14), 2832-2842.
25.      Jordan, R.; Martin, K.; Rader, H. J.; Unger, K. K., Lipopolymers for surface functionalizations. 1. Synthesis and characterization of terminal functionalized poly(N-propionylethylenimine)s. Macromolecules 2001, 34, (26), 8858-8865.
26.      Przybilla, L.; Brand, J. D.; Yoshimura, K.; Rader, H. J.; Mullen, K., MALDI-TOF mass spectrometry of insoluble giant polycyclic aromatic hydrocarbons by a new method of sample preparation. Analytical Chemistry 2000, 72, (19), 4591-4597.
27.      Weidmann, J. L.; Kern, J. M.; Sauvage, J. P.; Muscat, D.; Mullins, S.; Kohler, W.; Rosenauer, C.; Rader, H. J.; Martin, K.; Geerts, Y., Poly[2]catenanes and cyclic oligo[2]catenanes containing alternating topological and covalent bonds: Synthesis and characterization. Chemistry-a European Journal 1999, 5, (6), 1841-1851.
28.      Remmers, M.; Muller, B.; Martin, K.; Rader, H. J.; Kohler, W., Poly(p-phenylene)s. Synthesis, optical properties, and quantitative analysis with HPLC and MALDI-TOF mass spectrometry. Macromolecules 1999, 32, (4), 1073-1079.
29.      Przybilla, L.; Rader, H. J.; Mullen, K., Post-source decay fragment ion analysis of polycarbonates by matrix assisted laser desorption ionization time-of-flight mass spectrometry. European Mass Spectrometry 1999, 5, (2), 133-143.
30.      Muscat, D.; Kohler, W.; Rader, H. J.; Martin, K.; Mullins, S.; Muller, B.; Mullen, K.; Geerts, Y., Synthesis and characterization of poly[2]-catenanes containing rigid catenane segments. Macromolecules 1999, 32, (6), 1737-1745.
31.      Allgaier, J.; Martin, K.; Rader, H. J.; Mullen, K., Many-arm star polymers synthesized using chlorosilane linking agents: Their structural quality concerning arm number and polydispersity. Macromolecules 1999, 32, (10), 3190-3194.
32.      Servaty, S.; Kohler, W.; Meyer, W. H.; Rosenauer, C.; Spickermann, J.; Rader, H. J.; Wegner, G.; Weier, A., MALDI-TOF-MS copolymer analysis: Characterization of a poly(dimethylsiloxane)-co-poly(hydromethylsiloxane) as a precursor of a functionalized silicone graft copolymer. Macromolecules 1998, 31, (8), 2468-2474.
33.      Rader, H. J.; Schrepp, W., MALDI-TOF mass spectrometry in the analysis of synthetic polymers. Acta Polymerica 1998, 49, (6), 272-293.
34.      Klarner, G.; Former, C.; Martin, K.; Rader, J.; Mullen, K., Connective CC double bond formation for the synthesis of donor- and acceptor-substituted poly(p-phenylenevinylene)s. Macromolecules 1998, 31, (11), 3571-3577.
35.      Francke, V.; Rader, H. J.; Geerts, Y.; Mullen, K., Synthesis and characterization of a poly(para-phenyleneethynylene)-block-poly(ethylene oxide) rod-coil block copolymer. Macromolecular Rapid Communications 1998, 19, (6), 275-281.
36.      Hoger, S.; Spickermann, J.; Morrison, D. L.; Dziezok, P.; Ruder, H. J., Aggregates of shape persistent macrocyclic amphiphiles detected by MALDI-TOF spectroscopy. Macromolecules 1997, 30, (10), 3110-3111.
37.      Beer, F.; Gugel, A.; Martin, K.; Rader, J.; Mullen, K., High-yield reactive extraction of giant fullerenes from soot. Journal of Materials Chemistry 1997, 7, (8), 1327-1330.
38.      Spickermann, J.; Rader, H. J.; Mullen, K.; Muller, B.; Gerle, M.; Fischer, K.; Schmidt, M., MALDI-TOF characterization of macromonomers. Macromolecular Rapid Communications 1996, 17, (12), 885-896.
39.      Spickermann, J.; Martin, K.; Rader, H. J.; Mullen, K.; Schlaad, H.; Muller, A. H. E.; Kruger, R. P., Quantitative analysis of broad molecular weight distributions obtained by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry. European Mass Spectrometry 1996, 2, (2-3), 161-165.
40.      Sheiko, S. S.; Eckert, G.; Ignateva, G.; Muzafarov, A. M.; Spickermann, J.; Rader, H. J.; Moller, M., Solid-like states of a dendrimer liquid displayed by scanning force microscopy. Macromolecular Rapid Communications 1996, 17, (5), 283-297.
41.      Schweer, J.; Sarnecki, J.; MayerPosner, F.; Mullen, K.; Rader, H. J.; Spickermann, J., Pulsed-laser polymerization/matrix-assisted laser desorption/ionization mass spectrometry: An approach toward free-radical propagation rate coefficients of ultimate accuracy? Macromolecules 1996, 29, (13), 4536-4543.
42.      Schadler, V.; Spickermann, J.; Rader, H. J.; Wiesner, U., Synthesis and characterization of alpha,omega-macrozwitterionic block copolymers of styrene and isoprene. Macromolecules 1996, 29, (14), 4865-4870.
43.      Rader, H. J.; Spickermann, J.; Kreyenschmidt, M.; Mullen, K., MALDI-TOF mass spectrometry in polymer analytics .2. Molecular weight analysis of rigid-rod polymers. Macromolecular Chemistry and Physics 1996, 197, (10), 3285-3296.
44.      Martin, K.; Spickermann, J.; Rader, H. J.; Mullen, K., Why does matrix-assisted laser desorption/ionization time-of-flight mass spectrometry give incorrect results for broad polymer distributions? Rapid Communications in Mass Spectrometry 1996, 10, (12), 1471-1474.
45.      Rader, H. J.; Spickermann, J.; Mullen, K., MALDI-TOF MASS-SPECTROMETRY IN POLYMER ANALYTICS .1. MONITORING THE POLYMER-ANALOGOUS SULFONATION REACTION OF POLYSTYRENE. Macromolecular Chemistry and Physics 1995, 196, (12), 3967-3978.
46.      Bunz, U. H. F.; Enkelmann, V.; Rader, J., TRICARBONYL[ETA(5)-1,2,3,4,5-PENTAKIS(PROPYN-1-YL)CYCLOPENTADIENYL]-MANG ANESE. Organometallics 1993, 12, (12), 4745-4747.
47.      Kistenmacher, A.; Adam, M.; Baumgarten, M.; Pawlik, J.; Rader, H. J.; Mullen, K., SYNTHESIS OF NEW SOLUBLE TRIPHENODITHIAZINES AND INVESTIGATION OF THEIR DONOR PROPERTIES. Chemische Berichte-Recueil 1992, 125, (6), 1495-1500.
48.      Gugel, A.; Becker, M.; Hammel, D.; Mindach, L.; Rader, J.; Simon, T.; Wagner, M.; Mullen, K., PREPARATIVE-SCALE SEPARATION OF C-60 AND C-70 ON POLYSTYRENE GEL. Angewandte Chemie-International Edition in English 1992, 31, (5), 644-645.
49.      Bohnen, A.; Rader, H. J.; Mullen, K., CHARGING MECHANISMS OF EXTENDED PI-SYSTEMS - A CYCLOVOLTAMMETRIC APPROACH TO THE CLASSIFICATION OF REDOX POLYMERS AND CONDUCTING POLYMERS. Synthetic Metals 1992, 47, (1), 37-63.
50.      Anton, U.; Bohnen, A.; Koch, K. H.; Naarmann, H.; Rader, H. J.; Mullen, K., ON THE RELATION BETWEEN CHARGE-STORAGE CAPACITY AND PI-TOPOLOGY OF DIFFERENT OLIGONAPHTHYLENES. Advanced Materials 1992, 4, (2), 91-93.
51.      Adam, M.; Enkelmann, V.; Rader, H. J.; Rohrich, J.; Mullen, K., A DONOR CAGE WITH 2 TETRATHIAFULVALENE UNITS. Angewandte Chemie-International Edition in English 1992, 31, (3), 309-310.
52.      Bohnen, A.; Heitz, W.; Mullen, K.; Rader, H. J.; Schenk, R., REDOX-CHEMICAL INVESTIGATIONS OF SOLUBLE OLIGO (PARA-PHENYLENE)S. Makromolekulare Chemie-Macromolecular Chemistry and Physics 1991, 192, (8), 1679-1693.
53.      Adam, M.; Rader, H. J.; Rohrich, J.; Scherer, U.; Wolf, P.; Mullen, K., OLIGOMERIC TETRATHIAFULVALENES. Synthetic Metals 1991, 42, (1-2), 1623-1626.
54.      Adam, M.; Wolf, P.; Rader, H. J.; Mullen, K., CONJUGATED TRIS-TETRATHIAFULVALENES. Journal of the Chemical Society-Chemical Communications 1990, (22), 1624-1625.
55.      Schenk, R.; Hucker, J.; Hopf, H.; Rader, H. J.; Mullen, K., BIS-STILBENE SYSTEMS - REDUCTION TO THE TETRAANIONS. Angewandte Chemie-International Edition in English 1989, 28, (7), 904-906.
56.      Rader, H. J.; Scherer, U.; Wolf, P.; Mullen, K., CONJUGATED BIS-TETRATHIAFULVALENES - DONORS FOR A NEW CLASS OF CONDUCTING RADICAL CATION SALTS. Synthetic Metals 1989, 32, (1), 15-23.
57.      Heinz, W.; Rader, H. J.; Mullen, K., CHANGING THE SIZE OF A CAVITY VIA AN ELECTRON-TRANSFER - SYNTHESIS AND REDUCTION OF 1,5,22,26-TETRAOXA-[5,5]-(2,8)-DIBENZO[A,E]CYLOOCTATETRAENOPHANE. Tetrahedron Letters 1989, 30, (2), 159-162.
58.      Alexander, J.; Ehrenfreund, M.; Fiedler, J.; Huber, W.; Rader, H. J.; Mullen, K., STACK-TYPE REDOX SYSTEMS - SYNTHESIS VIA REPEATED CARBANION ALKYLATION AND ELECTRON-TRANSFER STUDIES. Angewandte Chemie-International Edition in English 1989, 28, (11), 1531-1533.