A luminescent dinuclear silver(i)-mediated base pair based on a bulky phenoxazine-derived artific... more A luminescent dinuclear silver(i)-mediated base pair based on a bulky phenoxazine-derived artificial nucleobase is reported.
Ab initio calculations are used to study defect-free attachment of functional molecules via nitro... more Ab initio calculations are used to study defect-free attachment of functional molecules via nitrogen incorporation at sulfur vacancies. This approach allows for stable modification while keeping the extraordinary properties of MoS2 monolayers.
A selective synthesis of relevant fluorescent compounds, indolizino[3,4,5-ab]isoindoles (INIs), t... more A selective synthesis of relevant fluorescent compounds, indolizino[3,4,5-ab]isoindoles (INIs), through a Mn(i)-catalyzed C–H activation on readily available 2-phenylpyridines is described.
Pt(ii) and Pd(ii) complexes with unprecedented photophysical properties were developed. Encapsula... more Pt(ii) and Pd(ii) complexes with unprecedented photophysical properties were developed. Encapsulation in nanoparticles boosted their performance while rendering them as self-referenced oxygen sensors.
Molecular photoswitches are versatile components for materials with bistable and photoreversible ... more Molecular photoswitches are versatile components for materials with bistable and photoreversible properties. Here, we enrich the functionality of the arylazoisoxazole molecular switch by analyzing its photoresponsive protonated Z- and E-isomers.
The cyclometalation reaction of [Pt(COD)(κ1-neoPh)]+ (neoPh = 2-methyl-2-phenylpropyl) to [Pt(COD... more The cyclometalation reaction of [Pt(COD)(κ1-neoPh)]+ (neoPh = 2-methyl-2-phenylpropyl) to [Pt(COD)(κ2-neoPh)] was studied experimentally and mechanistically using DFT and MD simulations.
Thermal treatment of the bicyclo[1.1.0]tetrasilatetraamide [Si4{N(SiMe3)Dipp}4] 1 resulted in the... more Thermal treatment of the bicyclo[1.1.0]tetrasilatetraamide [Si4{N(SiMe3)Dipp}4] 1 resulted in the formation of a highly unsaturated six-vertex silicon cluster [Si6{N(SiMe3)Dipp}4] 2 with only four amine-substituents and two ligand-free silicon atoms.
Two conformers of mononuclear ruthenium-(ii)–bis-terpyridine with markedly different emission spe... more Two conformers of mononuclear ruthenium-(ii)–bis-terpyridine with markedly different emission spectra have been identified in PMMA matrix by DFT calculations.
Free energies profiles for exciton transfer processes are calculated within ab initio molecular d... more Free energies profiles for exciton transfer processes are calculated within ab initio molecular dynamics by applying restraining potentials to the Wannier centres of molecular orbitals corresponding to an electron-hole pair.
Eine Reihe von Pt(II)‐Komplexen mit tetradentaten Luminophoren wurde entworfen, synthetisiert und... more Eine Reihe von Pt(II)‐Komplexen mit tetradentaten Luminophoren wurde entworfen, synthetisiert und mit dem Ziel auf Edelmetalloberflächen aufgebracht, hochplanare selbstassemblierte Monolagen herzustellen. Tieftemperatur‐Rastertunnelmikroskopie (STM) sowie Dichtefunktionaltheorie (DFT)‐Rechnungen zeigen eine erhebliche initiale Nichtplanarität für alle Komplexe. Anschließend wurde eine metallkatalysierte Spaltung der nichtplanaren Brückeneinheit via C−N Bindungsbruch beobachtet, die einen größtenteils planaren Kernkomplex zurücklässt. Die Aktivierungsbarriere für diesen Bindungsbruch hängt stark von der chemischen Struktur sowohl der Brückengruppe als auch der Koordinationsebene ab und steigt von Cu(111) über Ag(111) zu Au(111).
A highly stabilizing Cu(ii)-mediated base pair is introduced into DNA using a large artificial nu... more A highly stabilizing Cu(ii)-mediated base pair is introduced into DNA using a large artificial nucleobase.
Journal of the American Chemical Society, Jan 22, 2018
Acene imides are expected to possess smaller band gaps than homologous acenes while maintaining g... more Acene imides are expected to possess smaller band gaps than homologous acenes while maintaining good solubility and stability. However, the design and synthesis of large acene imides are still a big challenge. Herein, we report a one-pot synthesis of hexacene diimides (HDI) by double aromatic annulation between zirconabenzocyclopentene and tetrabrominated naphthalene diimides. HDIs with branched alkyl chains exhibit very good solubility, stability, and much smaller band gaps than hexacene. OFETs based on HDI microribbons exhibit excellent ambipolar transport behavior with the highest electron mobility of 2.17 cm2 V-1 s-1 and hole mobility of 0.30 cm2 V-1 s-1 under ambient condition.
The synthesis of new Pt(II) complexes bearing tailored cyclometalated C^N*N^C luminophores is rep... more The synthesis of new Pt(II) complexes bearing tailored cyclometalated C^N*N^C luminophores is reported along with their photophysical properties. The emission of the monomeric species can be blue shifted upon formal isosteric replacement of two C-H units by N atoms at the two cyclometalating rings. Their remarkable stability upon sublimation was demonstrated by means of scanning tunneling microscopy, which also revealed a defined self-assembly behavior leading to supramolecular arrays, showing a 3-fold symmetry in 2D-confined monolayers. The supramolecular organization is driven by van der Waals interactions of the side chains and does not depend on the nature of the luminophores, as also observed in the crystalline phases showing no significant Pt-Pt interactions in 3D. Conversely, the luminescence properties in glassy matrices at 77 K and in amorphous solids are indicative of intermolecular interactions with sizable intermetallic coupling, which was demonstrated by reproducing the...
Journal of the American Chemical Society, Jan 21, 2017
In here, we report the N-heterocyclic carbene (NHC)-induced activation of an otherwise unreactive... more In here, we report the N-heterocyclic carbene (NHC)-induced activation of an otherwise unreactive Pd/Al2O3 catalyst. Surface analysis techniques demonstrate the NHC being coordinated to the palladium particles and affecting their electronic properties. Fur-thermore, ab initio calculations provide additional insight into the electronic effect of the coordination with the NHC injecting electron density into the metal nanocluster thus lowering the barrier for bromobenzene activation. By this NHC modification, the catalyst could be successfully applied in the Buchwald-Hartwig amination of aryl chlorides, bromides, and iodides. Various heterogeneity tests could additionally show that the reaction proceeds via a heter-ogeneous active species.
The synthesis and characterization of various 6-oxo-verdazyl radicals and their diamagnetic styry... more The synthesis and characterization of various 6-oxo-verdazyl radicals and their diamagnetic styryl radical trapping products are presented.
External pulling force can be employed to manipulate optical switching properties of azobenzene m... more External pulling force can be employed to manipulate optical switching properties of azobenzene molecule which is a promising system for molecular electronics devices. We perform density functional treatment of azobenzene terminated by S-H groups with pulling force applied via restraints on the sulfur atoms. We treat the system both at zero and room temperature and among other quantities focus on
An atomistic force field has been adapted for use in molecular dynamics simulations of molecular ... more An atomistic force field has been adapted for use in molecular dynamics simulations of molecular materials that contain azobenzene (AB) functional groups. Force field parameters for bonded interactions and partial charges in the AB unit have been derived from ab initio molecular dynamics reference calculations. First applications of the new force field to liquid trans- and cis-AB are presented, both using a purely classical approach (MM) and a hybrid quantum-classical (QM/MM) simulation scheme. Detailed structural analysis confirms that QM/MM and purely MM simulations yield results that are in good agreement with each other. The force field of the AB core has been extended to include aliphatic chains that are attached via ether bridges to the two AB benzene rings. This allows for studying temperature induced phase transitions in the liquid-crystalline 8AB8 system. Using replica exchange techniques the new force field has successfully reproduced the smectic to isotropic-phase transition.
A luminescent dinuclear silver(i)-mediated base pair based on a bulky phenoxazine-derived artific... more A luminescent dinuclear silver(i)-mediated base pair based on a bulky phenoxazine-derived artificial nucleobase is reported.
Ab initio calculations are used to study defect-free attachment of functional molecules via nitro... more Ab initio calculations are used to study defect-free attachment of functional molecules via nitrogen incorporation at sulfur vacancies. This approach allows for stable modification while keeping the extraordinary properties of MoS2 monolayers.
A selective synthesis of relevant fluorescent compounds, indolizino[3,4,5-ab]isoindoles (INIs), t... more A selective synthesis of relevant fluorescent compounds, indolizino[3,4,5-ab]isoindoles (INIs), through a Mn(i)-catalyzed C–H activation on readily available 2-phenylpyridines is described.
Pt(ii) and Pd(ii) complexes with unprecedented photophysical properties were developed. Encapsula... more Pt(ii) and Pd(ii) complexes with unprecedented photophysical properties were developed. Encapsulation in nanoparticles boosted their performance while rendering them as self-referenced oxygen sensors.
Molecular photoswitches are versatile components for materials with bistable and photoreversible ... more Molecular photoswitches are versatile components for materials with bistable and photoreversible properties. Here, we enrich the functionality of the arylazoisoxazole molecular switch by analyzing its photoresponsive protonated Z- and E-isomers.
The cyclometalation reaction of [Pt(COD)(κ1-neoPh)]+ (neoPh = 2-methyl-2-phenylpropyl) to [Pt(COD... more The cyclometalation reaction of [Pt(COD)(κ1-neoPh)]+ (neoPh = 2-methyl-2-phenylpropyl) to [Pt(COD)(κ2-neoPh)] was studied experimentally and mechanistically using DFT and MD simulations.
Thermal treatment of the bicyclo[1.1.0]tetrasilatetraamide [Si4{N(SiMe3)Dipp}4] 1 resulted in the... more Thermal treatment of the bicyclo[1.1.0]tetrasilatetraamide [Si4{N(SiMe3)Dipp}4] 1 resulted in the formation of a highly unsaturated six-vertex silicon cluster [Si6{N(SiMe3)Dipp}4] 2 with only four amine-substituents and two ligand-free silicon atoms.
Two conformers of mononuclear ruthenium-(ii)–bis-terpyridine with markedly different emission spe... more Two conformers of mononuclear ruthenium-(ii)–bis-terpyridine with markedly different emission spectra have been identified in PMMA matrix by DFT calculations.
Free energies profiles for exciton transfer processes are calculated within ab initio molecular d... more Free energies profiles for exciton transfer processes are calculated within ab initio molecular dynamics by applying restraining potentials to the Wannier centres of molecular orbitals corresponding to an electron-hole pair.
Eine Reihe von Pt(II)‐Komplexen mit tetradentaten Luminophoren wurde entworfen, synthetisiert und... more Eine Reihe von Pt(II)‐Komplexen mit tetradentaten Luminophoren wurde entworfen, synthetisiert und mit dem Ziel auf Edelmetalloberflächen aufgebracht, hochplanare selbstassemblierte Monolagen herzustellen. Tieftemperatur‐Rastertunnelmikroskopie (STM) sowie Dichtefunktionaltheorie (DFT)‐Rechnungen zeigen eine erhebliche initiale Nichtplanarität für alle Komplexe. Anschließend wurde eine metallkatalysierte Spaltung der nichtplanaren Brückeneinheit via C−N Bindungsbruch beobachtet, die einen größtenteils planaren Kernkomplex zurücklässt. Die Aktivierungsbarriere für diesen Bindungsbruch hängt stark von der chemischen Struktur sowohl der Brückengruppe als auch der Koordinationsebene ab und steigt von Cu(111) über Ag(111) zu Au(111).
A highly stabilizing Cu(ii)-mediated base pair is introduced into DNA using a large artificial nu... more A highly stabilizing Cu(ii)-mediated base pair is introduced into DNA using a large artificial nucleobase.
Journal of the American Chemical Society, Jan 22, 2018
Acene imides are expected to possess smaller band gaps than homologous acenes while maintaining g... more Acene imides are expected to possess smaller band gaps than homologous acenes while maintaining good solubility and stability. However, the design and synthesis of large acene imides are still a big challenge. Herein, we report a one-pot synthesis of hexacene diimides (HDI) by double aromatic annulation between zirconabenzocyclopentene and tetrabrominated naphthalene diimides. HDIs with branched alkyl chains exhibit very good solubility, stability, and much smaller band gaps than hexacene. OFETs based on HDI microribbons exhibit excellent ambipolar transport behavior with the highest electron mobility of 2.17 cm2 V-1 s-1 and hole mobility of 0.30 cm2 V-1 s-1 under ambient condition.
The synthesis of new Pt(II) complexes bearing tailored cyclometalated C^N*N^C luminophores is rep... more The synthesis of new Pt(II) complexes bearing tailored cyclometalated C^N*N^C luminophores is reported along with their photophysical properties. The emission of the monomeric species can be blue shifted upon formal isosteric replacement of two C-H units by N atoms at the two cyclometalating rings. Their remarkable stability upon sublimation was demonstrated by means of scanning tunneling microscopy, which also revealed a defined self-assembly behavior leading to supramolecular arrays, showing a 3-fold symmetry in 2D-confined monolayers. The supramolecular organization is driven by van der Waals interactions of the side chains and does not depend on the nature of the luminophores, as also observed in the crystalline phases showing no significant Pt-Pt interactions in 3D. Conversely, the luminescence properties in glassy matrices at 77 K and in amorphous solids are indicative of intermolecular interactions with sizable intermetallic coupling, which was demonstrated by reproducing the...
Journal of the American Chemical Society, Jan 21, 2017
In here, we report the N-heterocyclic carbene (NHC)-induced activation of an otherwise unreactive... more In here, we report the N-heterocyclic carbene (NHC)-induced activation of an otherwise unreactive Pd/Al2O3 catalyst. Surface analysis techniques demonstrate the NHC being coordinated to the palladium particles and affecting their electronic properties. Fur-thermore, ab initio calculations provide additional insight into the electronic effect of the coordination with the NHC injecting electron density into the metal nanocluster thus lowering the barrier for bromobenzene activation. By this NHC modification, the catalyst could be successfully applied in the Buchwald-Hartwig amination of aryl chlorides, bromides, and iodides. Various heterogeneity tests could additionally show that the reaction proceeds via a heter-ogeneous active species.
The synthesis and characterization of various 6-oxo-verdazyl radicals and their diamagnetic styry... more The synthesis and characterization of various 6-oxo-verdazyl radicals and their diamagnetic styryl radical trapping products are presented.
External pulling force can be employed to manipulate optical switching properties of azobenzene m... more External pulling force can be employed to manipulate optical switching properties of azobenzene molecule which is a promising system for molecular electronics devices. We perform density functional treatment of azobenzene terminated by S-H groups with pulling force applied via restraints on the sulfur atoms. We treat the system both at zero and room temperature and among other quantities focus on
An atomistic force field has been adapted for use in molecular dynamics simulations of molecular ... more An atomistic force field has been adapted for use in molecular dynamics simulations of molecular materials that contain azobenzene (AB) functional groups. Force field parameters for bonded interactions and partial charges in the AB unit have been derived from ab initio molecular dynamics reference calculations. First applications of the new force field to liquid trans- and cis-AB are presented, both using a purely classical approach (MM) and a hybrid quantum-classical (QM/MM) simulation scheme. Detailed structural analysis confirms that QM/MM and purely MM simulations yield results that are in good agreement with each other. The force field of the AB core has been extended to include aliphatic chains that are attached via ether bridges to the two AB benzene rings. This allows for studying temperature induced phase transitions in the liquid-crystalline 8AB8 system. Using replica exchange techniques the new force field has successfully reproduced the smectic to isotropic-phase transition.
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