@article{XuCaoBrenneretal.2015,
  author    = {Xu, Jingsan and Cao, Shaowen and Brenner, Thomas J. K. and Yang, Xiaofei and Yu, Jiaguo and Antonietti, Markus and Shalom, Menny},
  title     = {Supramolecular Chemistry in Molten Sulfur: Preorganization Effects Leading to Marked Enhancement of Carbon Nitride Photoelectrochemistry},
  series = {Advanced functional materials},
  volume    = {25},
  journal   = {Advanced functional materials},
  number    = {39},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1616-301X},
  doi       = {10.1002/adfm.201502843},
  pages     = {6265 -- 6271},
  year      = {2015},
  abstract  = {Here, a new method for enhancing the photoelectrochemical properties of carbon nitride thin films by in situ supramolecular-driven preorganization of phenyl-contained monomers in molten sulfur is reported. A detailed analysis of the chemical and photophysical properties suggests that the molten sulfur can texture the growth and induce more effective integration of phenyl groups into the carbon nitride electrodes, resulting in extended light absorption alongside with improved conductivity and better charge transfer. Furthermore, photophysical measurements indicate the formation of sub-bands in the optical bandgap which is beneficial for exciton splitting. Moreover, the new bands can mediate hole transfer to the electrolyte, thus improving the photooxidation activity. The utilization of high temperature solvent as the polymerization medium opens new opportunities for the significant improvement of carbon nitride films toward an efficient photoactive material for various applications.},
  language  = {en}
}
@article{Titov2021,
  author    = {Titov, Evgenii},
  title     = {On the low-lying electronically excited states of azobenzene dimers},
  series = {Molecules : a journal of synthetic chemistry and natural product chemistry / Molecular Diversity Preservation International},
  volume    = {26},
  journal   = {Molecules : a journal of synthetic chemistry and natural product chemistry / Molecular Diversity Preservation International},
  number    = {14},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1420-3049},
  doi       = {10.3390/molecules26144245},
  pages     = {24},
  year      = {2021},
  abstract  = {Azobenzene-containing molecules may associate with each other in systems such as self-assembled monolayers or micelles. The interaction between azobenzene units leads to a formation of exciton states in these molecular assemblies. Apart from local excitations of monomers, the electronic transitions to the exciton states may involve charge transfer excitations. Here, we perform quantum chemical calculations and apply transition density matrix analysis to quantify local and charge transfer contributions to the lowest electronic transitions in azobenzene dimers of various arrangements. We find that the transitions to the lowest exciton states of the considered dimers are dominated by local excitations, but charge transfer contributions become sizable for some of the lowest pi pi* electronic transitions in stacked and slip-stacked dimers at short intermolecular distances. In addition, we assess different ways to partition the transition density matrix between fragments. In particular, we find that the inclusion of the atomic orbital overlap has a pronounced effect on quantifying charge transfer contributions if a large basis set is used.},
  language  = {en}
}
@article{SchwarzeRiemerHoldt2018,
  author    = {Schwarze, Thomas and Riemer, Janine and Holdt, Hans-J{\"u}rgen},
  title     = {A Ratiometric Fluorescent Probe for K+ in Water Based on a Phenylaza-18-Crown-6 Lariat Ether},
  series = {Chemistry - a European journal},
  volume    = {24},
  journal   = {Chemistry - a European journal},
  number    = {40},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0947-6539},
  doi       = {10.1002/chem.201802306},
  pages     = {10116 -- 10121},
  year      = {2018},
  abstract  = {This work presents two molecular fluorescent probes 1 and 2 for the selective determination of physiologically relevant K+ levels in water based on a highly K+/Na+ selective building block, the o-(2-methoxyethoxy)phenylaza-18-crown-6 lariat ether unit. Fluorescent probe 1 showed a high K+-induced fluorescence enhancement (FE) by a factor of 7.7 of the anthracenic emission and a dissociation constant (K-d) value of 38mm in water. Further, for 2+K+, we observed a dual emission behavior at 405 and 505nm. K+ increases the fluorescence intensity of 2 at 405nm by a factor of approximately 4.6 and K+ decreases the fluorescence intensity at 505nm by a factor of about 4.8. Fluorescent probe 2+K+ exhibited a K-d value of approximately 8mm in Na+-free solutions and in combined K+/Na+ solution a similar K-d value of about 9mm was found, reflecting the high K+/Na+ selectivity of 2 in water. Therefore, 2 is a promising fluorescent tool to measure ratiometrically and selectively physiologically relevant K+ levels.},
  language  = {en}
}
@article{SchwarzeKellingSperlichetal.2021,
  author    = {Schwarze, Thomas and Kelling, Alexandra and Sperlich, Eric and Holdt, Hans-J{\"u}rgen},
  title     = {Influence of regioisomerism in 9-anthracenyl-substituted dithiodicyanoethene derivatives on photoinduced electron transfer controlled by intramolecular charge transfer},
  series = {ChemPhotoChem},
  volume    = {5},
  journal   = {ChemPhotoChem},
  number    = {10},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {2367-0932},
  doi       = {10.1002/cptc.202100070},
  pages     = {911 -- 914},
  year      = {2021},
  abstract  = {In this paper, we report on the fluorescence behaviour of three regioisomers which consist of two 9-anthracenyl fluorophores and of differently substituted dithiodicyanoethene moieties. These isomeric fluorescent probes show different quantum yields (phi(f)). In these probes, an oxidative photoinduced electron transfer (PET) from the excited 9-anthracenyl fluorophore to the dithiodicyanoethene unit quenches the fluorescence. This quenching process is accelerated by an intramolecular charge transfer (ICT) of the push-pull pi-electron system of the dithiodicyanoethene group. The acceleration of the PET depends on the strength of the ICT unit. The higher the dipole moment of the ICT unit, the stronger the observed fluorescence quenching. To the best of our knowledge, this is the first report of a regioisomeric influence on an oxidative PET by an ICT.},
  language  = {en}
}
@article{PingelArvindKoellnetal.2016,
  author    = {Pingel, Patrick and Arvind, Malavika and K{\"o}lln, Lisa and Steyrleuthner, Robert and Kraffert, Felix and Behrends, Jan and Janietz, Silvia and Neher, Dieter},
  title     = {p-Type Doping of Poly(3-hexylthiophene) with the Strong Lewis Acid Tris(pentafluorophenyl)borane},
  series = {Advanced electronic materials},
  volume    = {2},
  journal   = {Advanced electronic materials},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {2199-160X},
  doi       = {10.1002/aelm.201600204},
  pages     = {7},
  year      = {2016},
  abstract  = {State-of-the-art p-type doping of organic semiconductors is usually achieved by employing strong -electron acceptors, a prominent example being tetrafluorotetracyanoquinodimethane (F(4)TCNQ). Here, doping of the semiconducting model polymer poly(3-hexylthiophene), P3HT, using the strong Lewis acid tris(pentafluorophenyl)borane (BCF) as a dopant, is investigated by admittance, conductivity, and electron paramagnetic resonance measurements. The electrical characteristics of BCF- and F(4)TCNQ-doped P3HT layers are shown to be very similar in terms of the mobile hole density and the doping efficiency. Roughly 18\% of the employed dopants create mobile holes in either F-4 TCNQ- or BCF-doped P3HT, while the majority of doping-induced holes remain strongly Coulomb-bound to the dopant anions. Despite similar hole densities, conductivity and hole mobility are higher in BCF-doped P3HT layers than in F(4)TCNQ-doped samples. This and the good solubility in many organic solvents render BCF very useful for p-type doping of organic semiconductors.},
  language  = {en}
}
@article{KogikoskiJuniorDuttaBald2021,
  author    = {Kogikoski Junior, Sergio and Dutta, Anushree and Bald, Ilko},
  title     = {Spatial separation of plasmonic hot-electron generation and a hydrodehalogenation reaction center using a DNA wire},
  series = {ACS nano},
  volume    = {15},
  journal   = {ACS nano},
  number    = {12},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1936-0851},
  doi       = {10.1021/acsnano.1c09176},
  pages     = {20562 -- 20573},
  year      = {2021},
  abstract  = {Using hot charge carriers far from a plasmonic nanoparticle surface is very attractive for many applications in catalysis and nanomedicine and will lead to a better understanding of plasmon-induced processes, such as hot-charge-carrier- or heat-driven chemical reactions. Herein we show that DNA is able to transfer hot electrons generated by a silver nanoparticle over several nanometers to drive a chemical reaction in a molecule nonadsorbed on the surface. For this we use 8-bromo-adenosine introduced in different positions within a double-stranded DNA oligonucleotide. The DNA is also used to assemble the nanoparticles into nanoparticles ensembles enabling the use of surface-enhanced Raman scattering to track the decomposition reaction. To prove the DNA-mediated transfer, the probe molecule was insulated from the source of charge carriers, which hindered the reaction. The results indicate that DNA can be used to study the transfer of hot electrons and the mechanisms of advanced plasmonic catalysts.},
  language  = {en}
}
@article{GhaniOpitzPingeletal.2015,
  author    = {Ghani, Fatemeh and Opitz, Andreas and Pingel, Patrick and Heimel, Georg and Salzmann, Ingo and Frisch, Johannes and Neher, Dieter and Tsami, Argiri and Scherf, Ullrich and Koch, Norbert},
  title     = {Charge Transfer in and Conductivity of Molecularly Doped Thiophene-Based Copolymers},
  series = {Journal of polymer science : B, Polymer physics},
  volume    = {53},
  journal   = {Journal of polymer science : B, Polymer physics},
  number    = {1},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0887-6266},
  doi       = {10.1002/polb.23631},
  pages     = {58 -- 63},
  year      = {2015},
  abstract  = {The electrical conductivity of organic semiconductors can be enhanced by orders of magnitude via doping with strong molecular electron acceptors or donors. Ground-state integer charge transfer and charge-transfer complex formation between organic semiconductors and molecular dopants have been suggested as the microscopic mechanisms causing these profound changes in electrical materials properties. Here, we study charge-transfer interactions between the common molecular p-dopant 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane and a systematic series of thiophene-based copolymers by a combination of spectroscopic techniques and electrical measurements. Subtle variations in chemical structure are seen to significantly impact the nature of the charge-transfer species and the efficiency of the doping process, underlining the need for a more detailed understanding of the microscopic doping mechanism in organic semiconductors to reliably guide targeted chemical design.},
  language  = {en}
}
@phdthesis{Bilkay2012,
  author    = {Bilkay, Taybet},
  title     = {Thiophen und Benzodithiophen basierte organische Halbleiter f{\"u}r aus L{\"o}sung prozessierbare Feldeffekttransistoren},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66164},
  school      = {Universit{\"a}t Potsdam},
  year      = {2012},
  abstract  = {Diese Arbeit befasst sich mit der Synthese und Charakterisierung von organol{\"o}slichen Thiophen und Benzodithiophen basierten Materialien und ihrer Anwendung als aktive lochleitende Halbleiterschichten in Feldeffekttransistoren. Im ersten Teil der Arbeit wird durch eine gezielte Modifikation des Thiophengrundger{\"u}stes eine neue Comonomer-Einheit f{\"u}r die Synthese von Thiophen basierten Copolymeren erfolgreich dargestellt. Die hydrophoben Hexylgruppen in der 3-Position des Thiophens werden teilweise durch hydrophile 3,6-Dioxaheptylgruppen ersetzt. {\"U}ber die Grignard-Metathese nach McCullough werden statistische Copolymere mit unterschiedlichen molaren Anteilen vom hydrophoben Hexyl- und hydrophilem 3,6-Dioxaheptylgruppen 1:1 (P-1), 1:2 (P-2) und 2:1 (P-3) erfolgreich hergestellt. Auch die Synthese eines definierten Blockcopolymers BP-1 durch sequentielle Addition der Comonomere wird realisiert. Optische und elektrochemische Eigenschaften der neuartigen Copolymere sind vergleichbar mit P3HT. Mit allen Copolymeren wird ein charakteristisches Transistorverhalten in einem Top-Gate/Bottom-Kontakt-Aufbau erhalten. Dabei werden mit P-1 als die aktive Halbleiterschicht im Bauteil, PMMA als Dielektrikum und Silber als Gate-Elektrode Mobilit{\"a}ten von bis zu 10-2 cm2/Vs erzielt. Als Folge der optimierten Grenzfl{\"a}che zwischen Dielektrikum und Halbleiter wird eine Verbesserung der Luftstabilit{\"a}t der Transistoren {\"u}ber mehrere Monate festgestellt. Im zweiten Teil der Arbeit werden Benzodithiophen basierte organische Materialien hergestellt. F{\"u}r die Synthese der neuartigen Benzodithiophen-Derivate wird die Schl{\"u}sselverbindung TIPS-BDT in guter Ausbeute dargestellt. Die Difunktionalisierung von TIPS-BDT in den 2,6-Positionen {\"u}ber eine elektrophile Substitution liefert die gew{\"u}nschten Dibrom- und Distannylmonomere. Zun{\"a}chst werden {\"u}ber die Stille-Reaktion alternierende Copolymere mit alkylierten Fluoren- und Chinoxalin-Einheiten realisiert. Alle Copolymere zeichnen sich durch eine gute L{\"o}slichkeit in g{\"a}ngigen organischen L{\"o}sungsmitteln, hohe thermische Stabilit{\"a}t und durch gute Filmbildungseigenschaften aus. Des Weiteren sind alle Copolymere mit HOMO Lagen h{\"o}her als -6.3 eV, verglichen mit den Thiophen basierten Copolymeren (P-1 bis P-3), sehr oxidationsstabil. Diese Copolymere zeigen amorphes Verhalten in den Halbleiterschichten in OFETs auf und es werden Mobilit{\"a}ten bis zu 10-4 cm2/Vs erreicht. Eine Abh{\"a}ngigkeit der Bauteil-Leistung von dem Zinngehalt-Rest im Polymer wird nachgewiesen. Ein Zinngehalt von {\"u}ber 0.6 \% kann enormen Einfluss auf die Mobilit{\"a}t aus{\"u}ben, da die funktionellen SnMe3-Gruppen als Fallenzust{\"a}nde wirken k{\"o}nnen. Alternativ wird das alternierende TIPS-BDT/Fluoren-Copolymer P-5-Stille nach der Suzuki-Methode polymerisiert. Mit P-5-Suzuki als die aktive organische Halbleiterschicht im OFET wird die h{\"o}chste Mobilit{\"a}t von 10-2 cm2/Vs erzielt. Diese Mobilit{\"a}t ist somit um zwei Gr{\"o}ßenordnungen h{\"o}her als bei P-5-Stille, da die Fallenzust{\"a}nde in diesem Fall minimiert werden und folglich der Ladungstransport verbessert wird. Sowohl das Homopolymer P-12 als auch das Copolymer mit dem aromatischen Akzeptor Benzothiadiazol P-9 f{\"u}hren zu schwerl{\"o}slichen Polymeren. Aus diesem Grund werden einerseits Terpolymere aus TIPS-BDT/Fluoren/BTD-Einheiten P-10 und P-11 aufgebaut und andererseits wird versucht die TIPS-BDT-Einheit in die Seitenkette des Styrols einzubringen. Mit der Einf{\"u}hrung von BTD in die Hauptpolymerkette werden insbesondere die Absorptions- und die elektrochemischen Eigenschaften beeinflusst. Im Vergleich zu dem TIPS-BDT/Fluoren-Copolymer reicht die Absorption bis in den sichtbaren Bereich und die LUMO Lage wird zu niederen Werten verschoben. Eine Verbesserung der Leistung in den Bauteilen wird jedoch nicht festgestellt. Die erfolgreiche erstmalige Synthese von TIPS-BDT als Seitenkettenpolymer an Styrol P-13 f{\"u}hrt zu einem l{\"o}slichen und amorphen Polymer mit vergleichbaren Mobilit{\"a}ten von Styrol basierten Polymeren (µ = 10-5 cm2/Vs) im OFET. Ein weiteres Ziel dieser Arbeit ist die Synthese von niedermolekularen organol{\"o}slichen Benzodithiophen-Derivaten. {\"U}ber Suzuki- und Stille-Reaktionen ist es erstmals m{\"o}glich, verschiedenartige Aromaten {\"u}ber eine σ-Bindung an TIPS-BDT in den 2,6-Positionen zu kn{\"u}pfen. Die UV/VIS-Untersuchungen zeigen, dass die Absorption durch die Verl{\"a}ngerung der π-Konjugationsl{\"a}nge zu h{\"o}heren Wellenl{\"a}ngen verschoben wird. Dar{\"u}ber hinaus ist es m{\"o}glich, thermisch vernetzbare Gruppen wie Allyloxy in das Molek{\"u}lger{\"u}st einzubauen. Das Einf{\"u}hren von F-Atomen in das Molek{\"u}lger{\"u}st resultiert in einer verst{\"a}rkten Packungsordnung im Fluorbenzen funktionalisiertem TIPS-BDT (SM-4) im Festk{\"o}rper mit sehr guten elektronischen Eigenschaften im OFET, wobei Mobilit{\"a}ten bis zu 0.09 cm2/Vs erreicht werden.},
  language  = {de}
}
@misc{AstFischerMuelleretal.2013,
  author    = {Ast, Sandra and Fischer, Tobias and M{\"u}ller, Holger and Mickler, Wulfhard and Schwichtenberg, Mathias and Rurack, Knut and Holdt, Hans-J{\"u}rgen},
  title     = {Integration of the 1,2,3-Triazole "Click" Motif as a potent signalling element in metal ion responsive fluorescent probes},
  series = {Chemistry - a European journal},
  volume    = {19},
  journal   = {Chemistry - a European journal},
  number    = {9},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0947-6539},
  doi       = {10.1002/chem.201201575},
  pages     = {2990 -- 3005},
  year      = {2013},
  abstract  = {In a systematic approach we synthesized a new series of fluorescent probes incorporating donoracceptor (D-A) substituted 1,2,3-triazoles as conjugative -linkers between the alkali metal ion receptor N-phenylaza-[18]crown-6 and different fluorophoric groups with different electron-acceptor properties (4-naphthalimide, meso-phenyl-BODIPY and 9-anthracene) and investigated their performance in organic and aqueous environments (physiological conditions). In the charge-transfer (CT) type probes 1, 2 and 7, the fluorescence is almost completely quenched by intramolecular CT (ICT) processes involving charge-separated states. In the presence of Na+ and K+ ICT is interrupted, which resulted in a lighting-up of the fluorescence in acetonitrile. Among the investigated fluoroionophores, compound 7, which contains a 9-anthracenyl moiety as the electron-accepting fluorophore, is the only probe which retains light-up features in water and works as a highly K+/Na+-selective probe under simulated physiological conditions. Virtually decoupled BODIPY-based 6 and photoinduced electron transfer (PET) type probes 35, where the 10-substituted anthracen-9-yl fluorophores are connected to the 1,2,3-triazole through a methylene spacer, show strong ion-induced fluorescence enhancement in acetonitrile, but not under physiological conditions. Electrochemical studies and theoretical calculations were used to assess and support the underlying mechanisms for the new ICT and PET 1,2,3-triazole fluoroionophores.},
  language  = {en}
}