Nanoscale Chemistry Research Team

Fullerenes Group

Head: Dr. A. Popov

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Functional Crystals in the Nanoscale Group

Head: Dr. S. Hampel

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Organic Single Crystals Group

Head: Dr. Yu. Krupskaya

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Spectroelectrochemistry Group

Head: Dr. E. Dmitrieva

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The morphology of nanoscale materials such as the size and the shape of the nanoparticles and nanocrystals can dramatically affect their properties. Research on nanoscale materials is motivated by the observation that materials, previously only known in their bulk phase, show a significant change in physical and chemical properties or even exhibit novel phenomena at the nanoscale due to a high surface-to-volume ratio and finite size effects. The thorough characterization and understanding of these properties in interplay with nanoscopic length scales will ultimately guide the way to the exploitation of these effects in applications, including high density storage media and biomedical materials. The group of nanoscale chemistry is focusing on the synthesis of inorganic, organic, and hybrid nanomaterials. For instance, we develop new methods to synthesize single-crystalline inorganic nanowires and nanocrystals directly inside the carbon nanotubes. On even a smaller scale, single metal ions and small clusters are encapsulated inside fullerenes during their formation in arc-discharge synthesis forming endohedral fullerenes. Carbon nanostructures in such hybrid materials act not only as templating matrices but also as protecting shields stabilizing the nanosized forms of inorganic materials. Unique electronic, transport, and magnetic properties of these hybrid heterostructures are achieved due to nanosize of encapsulated structures and the interface effects at the boundary with the carbon π-system are then studied in close cooperation with other groups of IFW. Reducing only one dimension to nanoscopic length scale we have to consider ultrathin layers of the materials. The charge carrier densities of ultrathin layers which are part of an electric double layer can be influenced strongly by applying an electrochemical potential. Our aim is to investigate how huge charge carrier densities will influence the electric and magnetic properties of appropriate materials. 

Fullerenes Group

The empty space inside the fullerene cage can be filled with atom, ions, clusters, or even small molecules. The fullerenes with encapsulated species are called endohedral fullerenes. Particular focus of our work is the synthesis of endohedral metallofullerenes (EMFs) with different clusters. The group in IFW Dresden pioneered in the development of the reactive atmosphere method, in which NH3 or CH4 gases are used as a source of nitrogen or hydrogen in the arc-discharge synthesis of EMF. More recent developments include the use of solid nitrogen-containing organic compounds as the sources of nitrogen. Reaction atmosphere method results in the dramatic suppression of the empty fullerene formation, leading to EMFs as the main fullerene products. We are also looking for new types of EMFs, which led to the discovery of such clusterfullerenes as Sc3CH@C80, Sc2S@C82, or TiLu2C@C80. Encapsulation of metal atoms within the carbon-based π-system results in a variety of unprecedented chemical and physical properties of EMFs. In IFW Dresden we are specifically focused on the electron-transfer mechanism in EMFs as studied by electrochemistry and spectroelectrochemistry, and on the magnetic properties of lanthanide-based EMFs, including their single molecule magnetism. Experimental studies are accompanied by quantum-chemical calculations of molecular structure, spectroscopic properties, and spin states.

Group Leader: Dr. Alexey Popov
Phone: +49 351 4659 871
Email

Syhthesis of EMFs and single-crystal X-ray diffraction: Dr. Fupin Liu
Phone: +49 351 4659 1130
Email

Computational studies of static and dynamic properties: Dr. Stanislav Avdoshenko
Phone: +49 351 4659 1130
Email

Dr.  Alexey A. Popov (Group leader)

Dr. Fupin Liuhead of the group "Synthesis and properties"

Dr. Stanislav Avdoshenkohead of the group"Computational studies"

 

PhD Students

Lukas Spree
Synthesis of EMFs and derivatives, magnetometry

Yaofeng Wang
Synthesis of EMFs and derivatives

Wei Yang
Synthesis of EMFs and derivatives

Vasilii Dubrovin
Quantum chemical calculations

Georgios Velkos
Magnetometry, XMCD

Emmanouil Koutsouflakis
Scanning tunneling microscopy

 

Technicians

Alex Beger

Marco Rosenkranz

Sandra Schiemenz

Frank Ziegs

 

Recent Alumni and Visitors

Victor Nekrasov, visiting PhD student (Moscow State University, 2019)
Yajuan Hao, visiting PhD student (Soochow University, 2018-2019)
Dr. Peter Machata, Postdoc (till 09.2019)
Svetlana Sudarkova, visiting PhD student (Moscow State University, 2018 and 2019)
Jimmy Kuo, visiting student (2-months DAAD Fellowship in 2018)
Dr. Christin Schlesier, PhD student (defense in November 2018)
Dr. Ariane Brandenburg, PhD student (defense in September 2018)
Dr. Chia-Hsiang Chen, Postdoc (till 07.2018)
Dr. Denis Krylov, PhD student (defense in June 2017)
Dr. Nataliya Samoylova, PhD student (defense in September 2017)
Dr. Katrin Junghans, PhD student (defense in May 2017)
Dr. Qingming Deng, PhD student (defense in May 2016)

Substrate‐independent magnetic bistability in monolayers of single molecule magnet Dy2ScN@C80 on metals and insulator
D. S. Krylov, S. Schimmel, V. Dubrovin, F. Liu, T. T. N. Nguyen, L. Spree, C.-H. Chen, G. Velkos, C. Bulbucan, R. Westerström, M. Studniarek, J. Dreiser, C. Hess, B. Büchner, S. M. Avdoshenko, A. A. Popov
Angew. Chem. Int. Ed. 2020,  in press DOI: 10.1002/anie.201913955

Air-stable redox-active nanomagnets with lanthanide spins radical-bridged by a metal-metal bond
F. Liu, G. Velkos, D. S. Krylov, L. Spree, M. Zalibera, R. Ray, N. A. Samoylova, C.-H. Chen, M. Rosenkranz, S. Schiemenz, F. Ziegs, K. Nenkov, A. Kostanyan, T. Greber, A. U. B. Wolter, M. Richter, B. Büchner, S. M. Avdoshenko, A. A. Popov
Nat. Commun.  2019, 10, 571. DOI: 10.1038/s41467-019-08513-6

Single-electron lanthanide-lanthanide bonds inside fullerenes toward robust redox-active molecular magnets
F. Liu, L. Spree, D. S. Krylov, G. Velkos, S. M. Avdoshenko, A. A. Popov
Acc. Chem. Res. 201952 (10), 2981-2993. DOI: 10.1021/acs.accounts.9b00373

Single molecule magnetism with strong magnetic anisotropy and enhanced Dy∙∙∙Dy coupling in three isomers of Dy-oxide clusterfullerene Dy2O@C82
W. Yang, G. Velkos, F. Liu, S. M. Sudarkova, Y. Wang, J. Zhuang, H. Zhang, X. Li, X. Zhang, B. Büchner, S. M. Avdoshenko, A. A. Popov, N. Chen
Adv. Sci. 2019, 1901352. DOI: 10.1002/advs.201901352

High blocking temperature of magnetization and giant coercivity in the azafullerene Tb2@C79N with a single-electron Tb–Tb bond
G. Velkos, D. S. Krylov, K. Kirkpatrick, L. Spree, V. Dubrovin, B. Büchner, S. M. Avdoshenko, V. Bezmelnitsyn, S. Davis, P. Faust, J. Duchamp, H. C. Dorn, A. A. Popov
Angew. Chem. Int. Ed.  201958, 5891.  DOI: 10.1002/anie.201900943

Thermally-activated delayed fluorescence in Y3N@C80 endohedral fullerene: time resolved luminescence and electron paramagnetic resonance studies
M. Zalibera, D. S. Krylov, D. Karagiannis, P.-A. Will, F. Ziegs, S. Schiemenz, W. Lubitz, S. Reineke, A. Savitsky, A. A. Popov
  Angew. Chem. Int. Ed.  2018130 (1), 283–287. DOI: 10.1002/anie.201710637

Record-high thermal barrier of the relaxation of magnetization in the nitride clusterfullerene Dy2ScN@C80-Ih
D. S. Krylov, F. Liu, S. M. Avdoshenko, L. Spree, B. Weise, A. Waske, A. U. B. Wolter, B. Büchner, A. A Popov
Chem. Commun. 201753, 7901-7904. DOI: 10.1039/C7CC03580B

Single molecule magnet with an unpaired electron trapped between two lanthanide ions inside a fullerene
F. Liu, D. S. Krylov, L. Spree, S. M. Avdoshenko, N. A. Samoylova, M. Rosenkranz, A. Kostanyan, T. Greber, A. U. B. Wolter, B. Büchner, A. A. Popov
Nat. Commun. 20178, 16098. DOI: 10.1038/ncomms16098

Synthesis and Structure of LaSc2N@Cs(hept)C80 with One Heptagon and Thirteen Pentagons
Y. Zhang, K. B. Ghiassi, Q. Deng, N. Samoylova, M. M. Olmstead, A. L. Balch, A. A. Popov
 Angew. Chem. Int. Ed. 201554 (2), 495-499. DOI: 10.1002/anie.201409094

 Perfluoroalkylfullerenes
O. V. Boltalina, A. A. Popov, I. V. Kuvychko, N. B. Shustova, S. H. Straus
Chem. Rev. 2015115, 1051-1105. DOI: 10.1021/cr5002595

Methane as a selectivity booster in the synthesis of endohedral fullerenes: towards selective synthesis of the single molecule magnet Dy2TiC@C80 and its congener Dy2TiC2@C80
K. Junghans, C. Schlesier, A. Kostanyan, N. A. Samoylova, Q. Deng, M. Rosenkranz, S. Schiemenz, R. Westerström, T. Greber, B. Büchner, A. A. Popov
 Angew. Chem. Int. Ed. 2015, 54 (45), 13411-13415. DOI: 10.1002/anie.201505870

Endohedral fullerene with μ3-carbido ligand and Titanium-Carbon double bond stabilized inside a carbon cage
A. L. Svitova, K. B. Ghiassi, C. Schlesier, K. Junghans, Y. Zhang, M. M. Olmstead, A. L. Balch, L. Dunsch, A. A. Popov
Nat. Commun. 20145, 3568. DOI: 10.1038/ncomms4568

Clusters encapsulated in Endohedral Metallofullerenes: How strained are they?
Q. Deng, A. A. Popov
J. Am. Chem. Soc. 2014136 (11), 4257-4264. DOI: 10.1021/ja4122582

 Endohedral Fullerenes
A. A. Popov, S. Yang, L. Dunsch
Chem. Rev. 2013113 (8), 5989–6113DOI: 10.1021/cr300297r

Bonding between strongly repulsive metal atoms: an oxymoron made real in a confined space of endohedral metallofullerenes
A. A. Popov, S. M. Avdoshenko, A. M. Pendás, L. Dunsch
Chem. Commun. 201248, 8031-8050. DOI: 10.1039/C2CC32568C

Internal @ IFW Dresden

  • Fullerene arc-discharge generators of local design
  • Full set of chromatographic (HPLC) equipment for separation of fullerene mixtures, including recycling HPLC
  • MALDI-TOF mass-spectrometry
  • Optical spectroscopy (UV-vis-NIR, FT-IR, Raman, luminescence), with microscopes and cryostates
  • X-band EPR spectroscopy
  • Solution NMR spectroscopy
  • Electrochemistry and spectroelectrochemistry

External

  • Single-crystal X-ray diffraction (mainly at BESSY)
  • Computational studies at supercomputor centers (mainly ZIH TU Dresden)
  • XAS/XMCD studies at synchrotron facilities (PSI, SOLEIL, BESSY)

 

Functional crystals on the nanoscale

Scaling a material down to nanometer-size reveals several opportunities to increase physical properties compared to bulk material or even create new ones. When quantum effects come into play electrical conductivity, magnetic permeability and chemical reactivity change as a function of particle size. Our approach uses carbon nanotubes (CNT) as a reaction container for the synthesis of intermetallic nanoparticles. With the given diameter of the tube particle size becomes adjustable. Furthermore the presence of the CNT-surrounding eases the reduction to metallic particle and protects nanoparticles from chemical influences (e.g. oxidation). Depending on the used material one obtains single particles or nano wires inside the inner cavity of the CNT. CNT have been filled for example with elements of main group IV in their metallic state. 3 different procedures to post synthetically fill the inner cavity of the CNT were used and by variation of the reaction parameters the appearance of filling particles, degree of filling and the purity of the samples in terms of coating to filling particle ratio can be tailored. These filled CNT with high rates of filling are promising for sensoric and energy storage applications.

 

The interest on 2D materials is rapidly growing and chemical approaches offer absolute control over the structure of 2D materials at the molecular-level. The chemical approach will serve as strategy to develop new multifunctional systems, featuring exceptional physical or chemical properties with optimal control over the correlation between structure and function. Our research currently focusses on the chemical vapor transport (CVT) in sealed ampules. One example is the CVT of bismuth chalcogenides nanostructures (Bi2Ch3; Ch = S, Se, Te) which can be synthesized by catalyst-free decomposition sublimation. The nanostructures directly grow on Si/SiO2 substrates by a vapor−solid growth mechanism and show high degree of crystallinity with dimensions of >10 μm in length and simultaneously <10 nm in height (nanoribbons). In order to optimize the growth process in a reproducible way we realize parallel thermodynamic calculations. The electrical transport data are evidence that this approach offers the chance to synthesize and investigate crystals with high quality and to measure surface state properties.

LUKSIAK: Lithium-basierte, umweltfreundliche, kostengünstige und stabile Ionen-Akku-Kathodenmaterialien

Projektlaufzeit: 01.01.2019 - 30.06.2021

Der anti-Perowskit (Li2Fe)SO (A-P) besitzt vielversprechende Eigenschaften für die Anwendung als Kathodenmaterial in Lithium-Ionen-Akkus. Mit einer Ladungsdichte von mehr als 200 mAh • g‒1 übertrifft A-P bereits die meisten herkömmlichen Materialien. (Li2Fe)SO kann mit hoher Ladegeschwindigkeit (1 C) im Akku zyklisiert werden, wobei der Kapazitätsverlust nur gering ausfällt. In unseren ersten Voruntersuchungen erreichten wir eine hohe Energiedichte mit 500 Wh • kg‒1 für einen Akku mit einer Lithium-Metall Anode und einer A-P Kathode. Im Weiteren besticht diese Materialklasse durch eine einfache und schnelle Synthese, wobei nur kostengünstige, nicht-toxische Edukte eingesetzt werden.

Um das Leistungsvermögen dieser neuen Materialklasse vollständig auszuschöpfen, soll die chemische Zusammensetzung durch Dotierung (Al, Mg) oder durch die Substitution gegen andere Elemente modifiziert werden. Im Hinblick für eine zukünftige industrielle Nutzung soll eine Aufskalierung und eine Optimierung der Synthese untersucht werden. Im Weiteren sollen die Leistungsparameter der hergestellten Test-Akkus optimiert werden. Wir streben eine Erhöhung der bereits hohen Ladegeschwindigkeit und der Ladungsdichte (auf über 300 mAh • g‒1) an. Außerdem soll die Akku-Lebensdauer auf über 1000 Zyklen sowie die Energiedichte auf über 600 Wh • kg‒1 gesteigert werden. Ausgehend aus diesen wissenschaftlichen Erkenntnissen soll ein Demonstrator entwickelt werden, der den vorgegebenen Parametern der Elektrofahrzeugindustrie erreicht oder gar übertrifft.

Kontakt: Dr. S. Hampel

Group Leader: Dr. Silke Hampel

Email

Phone: +49 351 4659 323

Organic single crystals

Group Leader: Dr. Yulia Krupskaya

Email

Phone: +49 351 4659 666

Spectroelectrochemistry

Spectroelectrochemistry as the combination of electrochemistry and different spectroscopic methods delivers detailed structural information on the intermediates and products in electrochemical reactions. By using different spectroelectrochemical methods formation and stabilization of charged species, follow-up processes, and mechanism of the electron transfer reaction can be investigated. To consolidate the spectroelectrochemical facilities of IFW and increase their visibility to other research groups and industrial partners, the Center of Spectroelectrochemistry was founded at the IFW Dresden in 2009 inspired by Prof. Dr. Lothar Dunsch.

The aims of the Center of Spectroelectrochemistry: 

- Basic research in spectroelectrochemistry 

- Development of spectroelectrochemical techniques  

- Application of spectroelectrochemical studies for applied research 

- International exchange of scientists for spectroelectrochemical research

- International training courses in spectroelectrochemistry

The center has expertise in various electrochemical and spectroscopic techniques and their combinations for in situ measurements, including in situ ESR, NMR, UV-vis-NIR, luminescence, IR, and Raman spectroelectrochemistry. These methods are applied to study the electrochemical electron transfer processes and intermediates of π-conjugated organic structures(small organic molecules, oligomers, conducting polymers etc.), carbon nanostructures (nanotubes, empty and endohedral fullerenes, and their functional derivatives etc.), hybrid molecular structures(organometallic compounds, coordination complexes, endohedral metallofullerenes etc.).

Group Leader: Dr. Evgenia Dmitrieva

Email: e.dmitrieva@ifw-dresden.de

Phone: +49 351 4659 658

E. Dmitrieva, M. Rosenkranz, J.S. Danilova, E.A. Smirnova, M.P. Karushev, I.A. Chepurnaya, A.M. Timonov
Radical formation in polymeric nickel complexes with N2O2 Schiff base ligands: An in situ ESR and UV-vis-NIR spectroelectrochemical study
Electrochimica Acta | 2019 | Volume: 283 | P. 1742-1752 | URL

E. Dmitrieva, M. Rosenkranz, Y. Alesanco, A. Viñuales
Spectroelectrochemical study of alkyl-aryl asymmetric viologens in poly(vinyl alcohol) (PVA) – borax electrolyte
Electrochimica Acta | 2018 | Volume: 323 | P. 134792 | URL

Z. Morávková, E. Dmitrieva
The First Products of Aniline Oxidation - SERS Spectroelectrochemistry
ChemistrySelect | 2017 | Volume: 4 | Issue: 30 | P. 8847 –8854 | URL

The Center of Spectroelectrochemistry in IFW has state-of-the-art equipment and expertise for in situ studies of the electrochemical electron transfer using IR, Raman, ESR, NMR, UV-vis-NIR and luminescence techniques. This list of spectroelectrochemical techniques available in the Center is quite unique, also on an international level.

Electrochemistry + spectroscopic method(s):

  • In situ ESR spectroelectrochemistry
  • In situ UV-vis-NIR spectroelectrochemistry
  • In situ ESR/UV-vis-NIR spectroelectrochemistry
  • In situ NMR spectroelectrochemistry
  • In situ Luminescence spectroelectrochemistry
  • In situ IR spectroelectrochemistry
  • In situ Raman spectroelectrochemistry