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  1. Article ; Online: Buckling up zigzag nanobelts.

    Esser, Birgit / Hermann, Mathias

    Nature chemistry

    2021  Volume 13, Issue 3, Page(s) 209–211

    Language English
    Publishing date 2021-02-10
    Publishing country England
    Document type Journal Article
    ZDB-ID 2464596-5
    ISSN 1755-4349 ; 1755-4330
    ISSN (online) 1755-4349
    ISSN 1755-4330
    DOI 10.1038/s41557-021-00642-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Book ; Thesis: In-vitro-Untersuchungen zu Empfindlichkeit und Resistenzverhalten von Pseudomonas aeruginosa

    Fechner, Hermann Mathias

    eine Studie über die Wirksamkeit von 12 Chemotherapeutika gegenüber 203 Isolaten von Pseudomonas aeruginosa am Klinikum der Universität Ulm

    1996  

    Author's details vorgelegt von Hermann Mathias Fechner
    Language German
    Size 109 S. : graph. Darst.
    Document type Book ; Thesis
    Thesis / German Habilitation thesis Ulm, Univ., Diss., 1997
    HBZ-ID HT010190708
    Database Catalogue ZB MED Medicine, Health

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    In stock of ZB MED Cologne/Königswinter

    Shelf markLoan statusLocation
    99 D 1111 order for loan Magazin

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  3. Article ; Online: Conjugated Nanohoops Incorporating Donor, Acceptor, Hetero- or Polycyclic Aromatics.

    Hermann, Mathias / Wassy, Daniel / Esser, Birgit

    Angewandte Chemie (International ed. in English)

    2021  Volume 60, Issue 29, Page(s) 15743–15766

    Abstract: In the last 13 years several synthetic strategies were developed that provide access to [n]cycloparaphenylenes ([n]CPPs) and related conjugated nanohoops. A number of potential applications emerged, including optoelectronic devices, and their use as ... ...

    Abstract In the last 13 years several synthetic strategies were developed that provide access to [n]cycloparaphenylenes ([n]CPPs) and related conjugated nanohoops. A number of potential applications emerged, including optoelectronic devices, and their use as templates for carbon nanomaterials and in supramolecular chemistry. To tune the structural or optoelectronic properties of carbon nanohoops beyond the size-dependent effect known for [n]CPPs, a variety of aromatic rings other than benzene were introduced. In this Review, we provide an overview of the syntheses, properties, and applications of conjugated nanohoops beyond [n]CPPs with intrinsic donor/acceptor structure or such that contain acceptor, donor, heteroaromatic or polycyclic aromatic units within the hoop as well as conjugated nanobelts.
    Language English
    Publishing date 2021-03-22
    Publishing country Germany
    Document type Journal Article ; Review
    ZDB-ID 2011836-3
    ISSN 1521-3773 ; 1433-7851
    ISSN (online) 1521-3773
    ISSN 1433-7851
    DOI 10.1002/anie.202007024
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  4. Article: Conjugated Nanohoops with Dibenzo[a,e]pentalenes as Nonalternant and Antiaromatic π-Systems

    Esser, Birgit / Wössner, Jan S. / Hermann, Mathias

    Synlett

    2022  Volume 33, Issue 08, Page(s) 737–753

    Abstract: Conjugated nanohoops are excellent as candidates for studying structure–property relationships, as optoelectronic materials, and as hosts for supramolecular chemistry. Whereas carbon nanohoops containing aromatics have been well studied, antiaromatic ... ...

    Abstract Conjugated nanohoops are excellent as candidates for studying structure–property relationships, as optoelectronic materials, and as hosts for supramolecular chemistry. Whereas carbon nanohoops containing aromatics have been well studied, antiaromatic units had not been incorporated until our group recently did so, using dibenzo[ a e ]pentalene (DBP). The nonalternant electronic character of the DBP units significantly influences the optoelectronic properties of such nanohoops. Here, we summarize our synthetic strategies toward DBP-containing nanohoops, together with their structural and electronic properties, chirality, and host–guest chemistry. We demonstrate how incorporating antiaromatic units leads to unique properties and opens new synthetic avenues, making such nanohoops attractive as potential electronic materials. 1

    Introduction 2

    Synthesis 3

    Structural Properties 4

    Electronic Properties 5

    Chirality 6

    Host–Guest Chemistry
    Keywords nanohoops ; antiaromaticity ; ambipolar materials ; chiroptical properties ; cycloparaphenylenes ; fullerene complexes
    Language German
    Publishing date 2022-01-14
    Publisher Georg Thieme Verlag KG
    Publishing place Stuttgart ; New York
    Document type Article
    ZDB-ID 2042012-2
    ISSN 1437-2096 ; 0936-5214
    ISSN (online) 1437-2096
    ISSN 0936-5214
    DOI 10.1055/a-1740-7139
    Database Thieme publisher's database

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  5. Article: Increased Antiaromaticity through Pentalene Connection in [n]Cyclo-1,5-dibenzopentalenes

    Wössner, Jan S. / Kohn, Julia / Wassy, Daniel / Hermann, Mathias / Grimme, Stefan / Esser, Birgit

    Organic letters. 2022 Jan. 14, v. 24, no. 4

    2022  

    Abstract: Conjugated nanohoops incorporating nonalternant hydrocarbons have altered optoelectronic properties compared to [n]cycloparaphenylenes or other purely aromatic hoops. We synthesized [n]cyclo-1,5-dibenzopentalenes (n = 4, 5), in which nonalternant dibenzo[ ...

    Abstract Conjugated nanohoops incorporating nonalternant hydrocarbons have altered optoelectronic properties compared to [n]cycloparaphenylenes or other purely aromatic hoops. We synthesized [n]cyclo-1,5-dibenzopentalenes (n = 4, 5), in which nonalternant dibenzo[a,e]pentalenes are connected through their pentalene units. This leads to an increase in antiaromatic character and low-lying LUMO energies. Calculations show puckered or entangled conformations of the precursor macrocyclic Pt-complexes. Our study proves dibenzopentalene as a versatile nonalternant building block for conjugated nanohoops with modifiable antiaromaticity and optoelectronic properties.
    Keywords cycloparaphenylenes ; energy ; exhibitions ; hydrocarbons
    Language English
    Dates of publication 2022-0114
    Size p. 983-988.
    Publishing place American Chemical Society
    Document type Article
    ISSN 1523-7052
    DOI 10.1021/acs.orglett.1c03900
    Database NAL-Catalogue (AGRICOLA)

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  6. Article ; Online: Increased Antiaromaticity through Pentalene Connection in [

    Wössner, Jan S / Kohn, Julia / Wassy, Daniel / Hermann, Mathias / Grimme, Stefan / Esser, Birgit

    Organic letters

    2022  Volume 24, Issue 4, Page(s) 983–988

    Abstract: Conjugated nanohoops incorporating nonalternant hydrocarbons have altered optoelectronic properties compared to [ ...

    Abstract Conjugated nanohoops incorporating nonalternant hydrocarbons have altered optoelectronic properties compared to [
    Language English
    Publishing date 2022-01-14
    Publishing country United States
    Document type Journal Article
    ISSN 1523-7052
    ISSN (online) 1523-7052
    DOI 10.1021/acs.orglett.1c03900
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: Enantiopure nanohoops through racemic resolution of diketo[

    Wassy, Daniel / Hermann, Mathias / Wössner, Jan S / Frédéric, Lucas / Pieters, Grégory / Esser, Birgit

    Chemical science

    2021  Volume 12, Issue 30, Page(s) 10150–10158

    Abstract: Strained conjugated nanohoops are attractive synthetic targets due to the bending of their π-system, which leads to intriguing optoelectronic properties, among others. By incorporating non-mirror-symmetric aromatic panels, chiral nanohoops can be ... ...

    Abstract Strained conjugated nanohoops are attractive synthetic targets due to the bending of their π-system, which leads to intriguing optoelectronic properties, among others. By incorporating non-mirror-symmetric aromatic panels, chiral nanohoops can be obtained. We herein present a strategy to enantiopure nanohoops by racemic resolution through chiral derivatization of diketone-embedded hoops. The resulting diketo[
    Language English
    Publishing date 2021-06-22
    Publishing country England
    Document type Journal Article
    ZDB-ID 2559110-1
    ISSN 2041-6539 ; 2041-6520
    ISSN (online) 2041-6539
    ISSN 2041-6520
    DOI 10.1039/d1sc02718b
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Cations and Anions of Dibenzo[a,e]pentalene and Reduction of a Dibenzo[a,e]pentalenophane.

    Hermann, Mathias / Böttcher, Tobias / Schorpp, Marcel / Richert, Sabine / Wassy, Daniel / Krossing, Ingo / Esser, Birgit

    Chemistry (Weinheim an der Bergstrasse, Germany)

    2021  Volume 27, Issue 15, Page(s) 4964–4970

    Abstract: Dibenzo[a,e]pentalene (DBP) is a non-alternant conjugated hydrocarbon with antiaromatic character and ambipolar electrochemical behavior. Upon both reduction and oxidation, it becomes aromatic. We herein study the chemical oxidation and reduction of a ... ...

    Abstract Dibenzo[a,e]pentalene (DBP) is a non-alternant conjugated hydrocarbon with antiaromatic character and ambipolar electrochemical behavior. Upon both reduction and oxidation, it becomes aromatic. We herein study the chemical oxidation and reduction of a planar DBP derivative and a bent DBP-phane. The molecular structures of its planar dication, cation radical and anion radical in the solid state demonstrate the gained aromaticity through bond length equalization, which is supported by nucleus independent chemical shift-calculations. EPR spectra on the cation radical confirm the spin delocalization over the DBP framework. A similar delocalization was not possible in the reduced bent DBP-phane, which stabilized itself by proton abstraction from a solvent molecule upon reduction. This is the first report on structures of a DBP cation radical and dication in the solid state and of a reduced bent DBP derivative. Our study provides valuable insight into the charged species of DBP for its application as semiconductor.
    Language English
    Publishing date 2021-02-12
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1478547-X
    ISSN 1521-3765 ; 0947-6539
    ISSN (online) 1521-3765
    ISSN 0947-6539
    DOI 10.1002/chem.202005131
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  9. Article ; Online: Dibenzo[a,e]pentalenophanes: Bending a Non-Alternant Hydrocarbon.

    Hermann, Mathias / Wassy, Daniel / Kratzert, Daniel / Esser, Birgit

    Chemistry (Weinheim an der Bergstrasse, Germany)

    2018  Volume 24, Issue 29, Page(s) 7374–7387

    Abstract: In cyclophanes, an aromatic moiety is incorporated into a (strained) cyclic structure. Of particular interest as model systems for bent carbon nanostructures are those containing polycyclic aromatic hydrocarbons. Dibenzo[a,e]pentalene (DBP) is a non- ... ...

    Abstract In cyclophanes, an aromatic moiety is incorporated into a (strained) cyclic structure. Of particular interest as model systems for bent carbon nanostructures are those containing polycyclic aromatic hydrocarbons. Dibenzo[a,e]pentalene (DBP) is a non-alternant polycyclic hydrocarbon with small band gap and tunable optoelectronic properties. However, changing these properties by bending of the DBP structure has yet to be investigated. Herein, we report the synthesis, optoelectronic, and structural properties of (2,7)dibenzo[a,e]pentalenophanes with four different bridge sizes and bending angles of the DBP unit, accompanied by (TD)DFT calculations. The last, strain-inducing dehydration reaction was accomplished by using Burgess' reagent. The HOMO and LUMO levels and the magnetic shielding of protons pointing inside the cyclophane cavity grew stepwise with increasing ring strain. Single-crystal X-ray structures of the smallest three derivatives revealed a near semi-circle and a bend angle of the DBP unit of almost 88° for the smallest derivative. We demonstrated the synthetic versatility of our approach by varying the substituents at the DBP unit, allowing for further tuning of optoelectronic properties. The synthetic strategy presented herein may pave the way for the synthesis of conjugated DBP nanorings.
    Language English
    Publishing date 2018-05-23
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1478547-x
    ISSN 1521-3765 ; 0947-6539
    ISSN (online) 1521-3765
    ISSN 0947-6539
    DOI 10.1002/chem.201800322
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  10. Article: Calix[n]phenothiazines: Optoelectronic and Structural Properties and Host–Guest Chemistry

    Schmidt, Maximilian / Hermann, Mathias / Otteny, Fabian / Esser, Birgit

    Organic Materials

    2020  Volume 02, Issue 03, Page(s) 235–239

    Abstract: Calixarenes are of interest as receptors for ions and small molecules and as organic materials. Exchanging the arene units through heteroaromatics allows changing their optoelectronic and host–guest properties. We herein present calix[ n ]phenothiazines ( ...

    Abstract Calixarenes are of interest as receptors for ions and small molecules and as organic materials. Exchanging the arene units through heteroaromatics allows changing their optoelectronic and host–guest properties. We herein present calix[ n ]phenothiazines ( n  = 3, 4) as novel macrocycles, accessible in two-step syntheses. The phenothiazine units show reversible redox events and emissive properties, and N -hexyl-substituted calix[3]phenothiazine binds to both ammonium ions and a bisimidazole as neutral guests.
    Keywords Calixarenes ; macrocycles ; phenothiazine ; host–guest chemistry ; conformational flexibility
    Language English
    Publishing date 2020-07-01
    Publisher Georg Thieme Verlag KG
    Publishing place Stuttgart ; New York
    Document type Article
    ZDB-ID 2933949-2
    ISSN 2625-1825 ; 2625-1825
    ISSN (online) 2625-1825
    ISSN 2625-1825
    DOI 10.1055/s-0040-1714295
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