0000000000037962

AUTHOR

Martin Baumgarten

showing 61 related works from this author

Dicyclopentaannelated Hexa-peri-hexabenzocoronenes with a Singlet Biradical Ground State

2021

Abstract Synthesis of two dicyclopentaannelated hexa‐peri‐hexabenzocoronene (PHBC) regioisomers was carried out, using nonplanar oligoaryl precursors with fluorenyl groups: mPHBC 8 with two pentagons in the “meta”‐configuration was obtained as a stable molecule, while its structural isomer with the “para”‐configuration, pPHBC 16, could be generated and characterized only in situ due to its high chemical reactivity. Both PHBCs exhibit low energy gaps, as reflected by UV‐vis‐NIR absorption and electrochemical measurements. They also show open‐shell singlet ground states according to electron paramagnetic resonance (EPR) measurements and density functional theory (DFT) calculations. The use of…

low energy gapnot-fully benzenoid PAH010402 general chemistryPhotochemistry01 natural sciencesCatalysislaw.inventiondicyclopentaannelationopen-shell biradicallawStructural isomerMoleculeSinglet stateElectron paramagnetic resonance010405 organic chemistryChemistryCommunicationAromaticityGeneral ChemistryCommunications0104 chemical sciencesDensity functional theoryPolycyclic Aromatic Hydrocarbons | Hot Paperhexa-peri-hexabenzocoroneneGround stateAntiaromaticityAngewandte Chemie International Edition
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Magnetic Exchange Interaction in Nitronyl Nitroxide Radical-Based Single Crystals of 3d Metal Complexes: A Combined Experimental and Theoretical Study

2018

Two stable nitronyl nitroxide free radicals {R1 = 4′-methoxy-phenyl-4,4,5,5,-tetramethylimidazoline-1-oxyl-3-oxide (NNPhOMe) and R2 = 2-(2′-thienyl)-4,4,5,5-tetramethylimidazoline 3-oxide 1-oxyl (NNT)} are successfully synthesized using Ullmann condensation. The reactions of these two radicals with 3d transition metal ions, in the form of M(hfac)2 (where M = Co or Mn, hfac: hexafluoroacetylacetone), result in four metal–organic complexes Co(hfac)2(NNPhOMe)2, 1; Co(hfac)2(NNT)2·(H2O), 2; Mn(hfac)2(NNPhOMe)·x(C7H16), 3; and Mn(hfac)2(NNT)2, 4. The crystal structure and magnetic properties of these complexes are investigated by single-crystal X-ray diffraction, dc magnetization, infrared, and …

Nitroxide mediated radical polymerizationMaterials science010405 organic chemistryGeneral Chemical EngineeringRadicalGeneral Chemistry010402 general chemistryPhotochemistry01 natural sciencesNitroxide radicalArticle0104 chemical sciencesMagnetic exchangeMetallcsh:Chemistrylcsh:QD1-999visual_artvisual_art.visual_art_mediumACS Omega
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Bulky, Dendronized Iridium Complexes and their Photoluminescence

2019

Solution-processed blue emitters are essential for low-cost organic light-emitting diodes (OLEDs) but still face challenges due to their poor color purity, low efficiency and limited operational stability. Herein, by extending the conjugation of ultraviolet-emissive, facial tris(diphenylbenzimidazolyl)iridium (Ir) (fac-(dpbic)3Ir), we introduce two new types of solution-processed emitters, i.e. triisopropylsilylethynyl(TIPSE)-substituted fac-(dpbic)3Ir (2) and fac-(dpbic)3Ir-based polyphenylene dendrimers D1 and D2. The emissions of Ir-complex 2 and the dendrimers were successfully pushed toward a pure and sky blue color, respectively, due to the dominant 3π–π* nature of their emissive exci…

Steric effectsSolar cells of the next generationMaterials sciencePhotoluminescencechemistry.chemical_element02 engineering and technologyGeneral Chemistry010402 general chemistry021001 nanoscience & nanotechnologyPhotochemistry01 natural sciences0104 chemical scienceschemistryExcited stateDendrimerMaterials ChemistryOLEDIridium0210 nano-technologyPhosphorescenceDiode
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Planar Benzo[1,2-b:4,5-b′]dithiophene Derivatives Decorated with Nitronyl and Imino Nitroxides

2018

Four weakly antiferromagnetic interacting biradicals of benzo[1,2- b:4,5- b']dithiophene (BDT) and BDT extended with two thiophenes (BDTTh2) linked with nitronyl and imino nitroxides (NN and IN) as BDT-NN, BDT-IN, BDTTh2-NN, and BDTTh2-IN were designed, synthesized, and characterized. Short intermolecular π-π distances were found (3.42 A) for BDT-NN, whereas larger ones were found for BDT-IN (3.54 A) and BDTTh2-NN (3.67 A), respectively. Intramolecular magnetic interaction ( Jintra,exp/ kB) of BDT-NN (-26 K) is much larger than for BDT-IN (-5.3 K), while it is reduced for the dithiophene-extended molecule BDTTh2-NN (-2.3 K). Intermolecular interactions ( zJinter,exp/ kB) of BDT-NN (-6.5 K) …

010405 organic chemistryChemistryOrganic ChemistryCrystalline materialsIntermolecular force010402 general chemistry01 natural sciences0104 chemical sciencesCrystallographyPlanarIntramolecular forceAntiferromagnetismMoleculeMagnetic interactionSpin (physics)The Journal of Organic Chemistry
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Electronic structure of large disc-type donors and acceptors

2010

Searching for new pi-conjugated charge-transfer systems, the electronic structure of a new acceptor-donor pair derived from coronene (C(24)H(12)) was investigated by ultraviolet photoelectron spectroscopy (UPS). The acceptor coronene-hexaone (C(24)H(6)O(6), in the following abbreviated as COHON) and the donor hexamethoxycoronene (C(30)H(24)O(6), abbreviated as HMC) were adsorbed as pure and mixed phases on gold substrates. At low coverage, COHON adsorption leads to the appearance of a charge-transfer induced interface state 1.75 eV below the Fermi energy. At multilayer coverage the photoemission intensity of the interface state drops and the valence spectrum of neutral COHON appears. The sa…

Valence (chemistry)Nuclear magnetic resonancePhotoemission spectroscopyChemistryBinding energyGeneral Physics and AstronomyWork functionDensity functional theoryElectronic structurePhysical and Theoretical ChemistryMolecular physicsAcceptorUltraviolet photoelectron spectroscopyPhysical Chemistry Chemical Physics
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Charge transfer in the novel donor-acceptor complexes tetra- and hexamethoxypyrene with tetracyanoquinodimethane studied by HAXPES

2012

Abstract The effect of charge transfer (CT) in complexes of the donors tetra - and hexamethoxyprene ( TMP and HMP ) with the classical acceptor tetracyanoquinodimethane ( TCNQ ) was studied using hard X-ray photoemission (HAXPES). Microcrystals of the complex were grown via vapour diffusion from donor–acceptor mixtures. The bulk sensitivity of HAXPES at a photon energy of 6 keV completely eliminates the problem of surface contamination for such delicate organic materials grown from solution. The donor molecules were produced using a novel synthesis route functionalizing polycyclic aromatic hydrocarbons at their periphery. For comparison, spectra were also taken from thin-film samples of the…

RadiationAnalytical chemistrychemistry.chemical_elementCondensed Matter PhysicsTetracyanoquinodimethaneAcceptorOxygenAtomic and Molecular Physics and OpticsXANESSpectral lineElectronic Optical and Magnetic MaterialsCrystallographychemistry.chemical_compoundchemistryMoleculePhysical and Theoretical ChemistryAbsorption (chemistry)ddc:620SpectroscopyUltraviolet photoelectron spectroscopy
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Regioselective Bromination and Functionalization of Dibenzo[hi,st]ovalene as Highly Luminescent Nanographene with Zigzag Edges.

2019

Dibenzo[hi,st]ovalene (DBOV) is a nanographene with a combination of zigzag and armchair edges, consisting of 38 sp2 carbons. Excellent optical properties with strong red emission have been demonstrated. Here we report the regioselective bromination of DBOV bearing two mesityl groups (DBOV-Mes) by treatment with N-bromosuccinimide (NBS) under mild conditions. The dibrominated DBOV was further subjected to transition-metal-catalyzed cross-coupling reactions, that is, Suzuki and Sonogashira coupling, demonstrating the edge-decoration of DBOV with different functional groups. Notably, DBOVs arylated at the bay regions showed intense red emission and enhanced fluorescence quantum yields of up t…

010405 organic chemistryChemistryOrganic ChemistrySonogashira couplingRegioselectivityHalogenationGeneral ChemistryOvalene010402 general chemistry01 natural sciencesBiochemistryRedox0104 chemical scienceschemistry.chemical_compoundRadical ionPolymer chemistryCyclic voltammetryLuminescenceChemistry, an Asian journal
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Microscopic origin of the charge transfer in single crystals based on thiophene derivatives: A combined NEXAFS and density functional theory approach

2016

We have investigated the charge transfer mechanism in single crystals of DTBDT-TCNQ and DTBDT-F4TCNQ (where DTBDT is dithieno[2,3-d;2',3'-d'] benzo[1,2-b;4,5-b']dithiophene) using a combination of near-edge X-ray absorption spectroscopy (NEXAFS) and density functional theory calculations (DFT) including final state effects beyond the sudden state approximation. In particular, we find that a description that considers the partial screening of the electron-hole Coulomb correlation on a static level as well as the rearrangement of electronic density shows excellent agreement with experiment and allows to uncover the details of the charge transfer mechanism in DTBDT-TCNQ and DTBDT-F4 TCNQ, as w…

Absorption spectroscopyExtended X-ray absorption fine structureChemistryAnalytical chemistryGeneral Physics and Astronomy02 engineering and technology021001 nanoscience & nanotechnology01 natural sciencesMolecular physicsXANES0103 physical sciencesAtomCoulombDensity functional theoryAtomic numberPhysical and Theoretical Chemistry010306 general physics0210 nano-technologyElectronic densityThe Journal of Chemical Physics
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Orbital-Resolved Partial Charge Transfer from the Methoxy Groups of Substituted Pyrenes in Complexes with Tetracyanoquinodimethane—A NEXAFS Study

2012

It is demonstrated that the near-edge X-ray absorption fine structure (NEXAFS) provides a powerful local probe of functional groups in novel charge transfer (CT) compounds and their electronic properties. Microcrystals of tetra-/hexamethoxypyrene as donors with the strong acceptor tetracyano-p-quinodimethane (TMP/HMP-TCNQ) were grown by vapor diffusion. The oxygen and nitrogen K-edge spectra are spectroscopic fingerprints of the functional groups in the donor and acceptor moieties, respectively. The orbital selectivity of the NEXAFS pre-edge resonances allows us to precisely elucidate the participation of specific orbitals in the charge transfer process. Upon complex formation, the intensit…

ChemistryResonanceGeneral ChemistryPhotochemistryBiochemistryAcceptorTetracyanoquinodimethaneCatalysisXANESSpectral linechemistry.chemical_compoundPartial chargeColloid and Surface ChemistryAtomic orbitalSelectivityJournal of the American Chemical Society
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Cover Picture: Scaffold-Optimized Dendrimers for the Detection of the Triacetone Triperoxide Explosive Using Quartz Crystal Microbalances (ChemPlusCh…

2012

CrystalScaffoldExplosive materialChemistryDendrimerNanotechnologyCover (algebra)General ChemistryQuartzChemPlusChem
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Oligofluorene with multiple spiro-connections: its and their use in blue and white OLEDs

2019

Bond rotation within molecules is regarded as one of the nonradiative decay pathways and is detrimental to high photoluminescence quantum yields. In this work, a bulky and rigid blue emitter (Spiro-F) with five spiro-carbon linkages is synthesized. Spiro-F can serve not only as an active component of blue organic light-emitting diodes (OLEDs), but also as a host and blue emitter of white OLEDs. The WOLED offers a low turn-on voltage of 3.5 V and a high current efficiency of 3.6 cd A−1, together with CIE coordinates of (0.29, 0.33). This work proves the potential of super-rigid oligofluorene emitters for OLEDs.

PhotoluminescenceChemistrybusiness.industry02 engineering and technologyGeneral Chemistry010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesCatalysis0104 chemical sciencesActive componentMaterials ChemistryOLEDMoleculeOptoelectronics0210 nano-technologybusinessDiodeCommon emitterNew Journal of Chemistry
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Spiro-fused bis-hexa-peri-hexabenzocoronene.

2018

A spiro-fused hexa-peri-hexabenzocoronene dimer was synthesized, and its physicochemical properties were studied by UV-Vis absorption and emission spectroscopy as well as cyclic voltammetry. Chemical oxidation of SB-HBC afforded its radical cation and dication derivatives, which could be reversibly reduced to the neutral state.

010405 organic chemistryChemistryDimerMetals and AlloysHexa-peri-hexabenzocoroneneGeneral Chemistry010402 general chemistry01 natural sciencesCatalysis0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsDicationchemistry.chemical_compoundRadical ionPolymer chemistryMaterials ChemistryCeramics and CompositesEmission spectrumCyclic voltammetryAbsorption (chemistry)Neutral stateChemical communications (Cambridge, England)
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Formation of an intermolecular charge-transfer compound in UHV codeposited tetramethoxypyrene and tetracyanoquinodimethane

2010

Ultrahigh vacuum (UHV)-deposited films of the mixed phase of tetramethoxypyrene and tetracyanoquinodimethane $({\text{TMP}}_{1}{\text{-TCNQ}}_{1})$ on gold have been studied using ultraviolet photoelectron spectroscopy (UPS), x-ray diffraction (XRD), infrared (IR) spectroscopy, and scanning tunneling spectroscopy (STS). The formation of an intermolecular charge-transfer (CT) compound is evident from the appearance of new reflexes in XRD (${d}_{1}=0.894\text{ }\text{nm}$ and ${d}_{2}=0.677\text{ }\text{nm}$). A softening of the CN stretching vibration (redshift by $7\text{ }{\text{cm}}^{\ensuremath{-}1}$) of TCNQ is visible in the IR spectra, being indicative of a CT on the order of $0.3e$ f…

Materials scienceOrder (ring theory)Infrared spectroscopyCondensed Matter PhysicsTetracyanoquinodimethaneElectronic Optical and Magnetic Materialschemistry.chemical_compoundCrystallographyNuclear magnetic resonancechemistryContent (measure theory)Molecular orbitalSpectroscopyHOMO/LUMOUltraviolet photoelectron spectroscopyPhysical Review B
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Hydrophobic Encapsulated Phosphonium Salts-Synthesis of Weakly Coordinating Cations and their Application in Wittig Reactions

2015

Large and rigid tetraarylphosphonium tetrafluoroborate salts have been synthesized representing weakly coordinating cations with diameters of several nanometers. Divergent dendritic growth by means of thermal Diels-Alder cycloaddition was employed for the construction of the hydrophobic polyphenylene framework up to the third generation. X-ray crystal structure analysis of first-generation phosphonium tetrafluoroborate supported the rigidity of the non-collapsible shell around the phosphorus center and gave insight into solid-state packing and cation-anion distances. Copper(I)-catalyzed azide-alkyne ligation served as reliable method for the preparation of a first-generation triazolylphenyl…

Reaction conditionsTetrafluoroborateOrganic Chemistrychemistry.chemical_elementGeneral ChemistryCrystal structureCopperCatalysisThird generationCycloadditionchemistry.chemical_compoundchemistryPolymer chemistryWittig reactionOrganic chemistryPhosphoniumChemistry - A European Journal
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Dipolar Relaxation in Functionalized Poly-p-phenylenes Bearing Ultrastrong Dipoles Perpendicular to the Backbone

2018

Local polymer dynamics are studied in polymers bearing dipoles rigidly attached to the backbone. The compounds are based on cyano-substituted dihydrobenzimidazoles bearing ultrastrong dipole moments (∼12 D per repeat unit) incorporated in a poly-p-phenylene backbone, giving rise to polymers with rigid dipoles perpendicular to the chain. They belong to type B polymers according to the Stockmayer classification. They are ideal model systems for studying rotational isomers in the gas phase and the self-assembly and local dynamics in the solid state. Gas phase calculations (DFT) provided the dipole moments, the energetic barriers, and the backbone conformation as a function of the dipole streng…

chemistry.chemical_classificationQuantitative Biology::BiomoleculesBearing (mechanical)Materials sciencePolymers and PlasticsOrganic ChemistryIntermolecular forcePolymerMolecular physicslaw.inventionDielectric spectroscopyInorganic ChemistryDipolechemistrylawMoment (physics)Materials ChemistryPerpendicularPhysics::Atomic PhysicsRepeat unitMacromolecules
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Investigation of Many‐Body Effects in the Quasi‐Two‐Dimensional Electronic System of Organic Charge‐Transfer Salts

2019

SuperconductivityX-ray absorption spectroscopyMaterials scienceCondensed matter physicslawCharge (physics)Electronic structureScanning tunneling microscopeCondensed Matter PhysicsElectronic systemsMany bodyElectronic Optical and Magnetic Materialslaw.inventionphysica status solidi (b)
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Theoretical study of new acceptor and donor molecules based on polycyclic aromatic hydrocarbons

2011

Functionalized polcyclic aromatic hydrocarbons (PAHs) are an interesting class of molecules in which the electronic state of the graphene-like hydrocarbon part is tuned by the functional group. Searching for new types of donor and acceptor molecules, a set of new PAHs has recently been investigated experimentally using ultraviolet photoelectron spectroscopy (UPS). In this work, the electronic structure of the PAHs is studied numerically with the help of B3LYP hybrid density functionals. Using the DELTA-SCF method, electron binding energies have been determined which affirm, specify and complement the UPS data. Symmetry properties of molecular orbitals are analyzed for a categorization and a…

Chemical Physics (physics.chem-ph)Materials scienceCondensed Matter - Mesoscale and Nanoscale PhysicsKoopmans' theoremFOS: Physical sciencesElectronic structureCharge-transfer complexAcceptorAtomic and Molecular Physics and OpticsCondensed Matter::Materials ScienceElectron affinity (data page)Chemical physicsPhysics - Chemical PhysicsMesoscale and Nanoscale Physics (cond-mat.mes-hall)Molecular orbitalPhysics::Chemical PhysicsPhysical and Theoretical ChemistryAtomic physicsHOMO/LUMOSpectroscopyBasis setJournal of Molecular Spectroscopy
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Layered Thiadiazoloquinoxaline-Containing Long Pyrene-Fused N-Heteroacenes

2018

Three thiadiazoloquinoxaline-containing long pyrene-fused N-heteroacenes with 8, 13, and 18 rings were designed and synthesized. They show high electron affinities (EAs) of approximately 4.1 eV, which were derived from the onset of the reduction peaks in cyclic voltammetry. Crystal structure analysis revealed in-plane extension through close contacts between thiadiazole units as well as layered packing, enabling in-plane and interlayer electron transport. Organic field-effect transistor devices provided electron mobilities, which suggest a potential way to enhance the charge transport in long N-heteroacenes.

Materials science010405 organic chemistryTransistorGeneral MedicineGeneral ChemistryElectronCrystal structure010402 general chemistry01 natural sciencesElectron transport chainAffinitiesCatalysis0104 chemical scienceslaw.inventionCrystallographychemistry.chemical_compoundchemistrylawPyreneCyclic voltammetryHigh electronAngewandte Chemie International Edition
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The Generation Effect: Cavity Accessibility in Dense‐Shell Polyphenylene Dendrimers

2014

Size exclusion is a widespread phenomenon in supra- and macromolecular chemistry. Herein, the size exclusion properties of polyphenylene dendrimers on the surface of high fundamental frequency quartz crystal microbalances are reported. For this purpose, a new dense fifth-generation polyphenylene dendrimer, which was previously not possible owing to the high steric demand of the dendron arms, was synthesized. By increasing the volume and size of subjected analytes an affinity shift from smaller to larger dendrimers can be obtained.

Steric effectsCrystalMolecular recognitionMaterials scienceChemical engineeringDendrimerPolymer chemistrySize-exclusion chromatographySupramolecular chemistryShell (structure)General ChemistryQuartzChemPlusChem
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Hexasubstituted Benzenes with Ultrastrong Dipole Moments

2015

Hexasubstituted benzenes have been synthesized with the highest known dipole moments, as determined by dielectric spectroscopy and DFT methods. Based on the preparation of 4,5-diamino-3,6-dibromophthalonitrile, combined with a novel method to synthesize dihydrobenzimidazoles, these benzene derivatives have dipole moments in excess of 10 debye. Such dipole moments are desirable in ferroelectrics, nonlinear optics, and in organic photovoltaics. Structure determination was achieved through single-crystal X-ray crystallography, and the optical properties were determined by UV/Vis absorption and fluorescence spectroscopy.

Organic solar cellChemistryNonlinear optics02 engineering and technologyGeneral ChemistryElectrophilic aromatic substitution010402 general chemistry021001 nanoscience & nanotechnology01 natural sciencesCatalysisFluorescence spectroscopy0104 chemical sciencesDielectric spectroscopyDipoleNuclear magnetic resonanceBenzene derivativesPhysical chemistry0210 nano-technologyAbsorption (electromagnetic radiation)Angewandte Chemie International Edition
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Scaffold-Optimized Dendrimers for the Detection of the Triacetone Triperoxide Explosive Using Quartz Crystal Microbalances

2012

CrystalScaffoldMaterials scienceExplosive materialDendrimerAnalytical chemistryNanotechnologyGeneral ChemistryQuartzChemPlusChem
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Tailoring the Emission of Fluorinated Bipyridine-Chelated Iridium Complexes

2018

New functionalized tris(2′,6′-difluoro-2,3′-bipyridinato-N,C4′)iridium(III) ((dfpypy)3Irs) complexes, including small molecules and their dendrimer embedded analogoues, were synthesized and characterized. It is demonstrated that both the fac-(dfpypy)3Ir-based polyphenylene dendrimers and (triisopropylsilyl)ethynyl (TIPSE)-substituted (dfpypy)3Ir complexes induce large bathochromic shifts (∼50 nm) of emission bands compared with fac-(dfpypy)3Ir. This is due to the pronounced 3π–π* character of emissive excited states and the extended conjugation. A further remarkable feature is the small bathochromic shift of the emissions of fac-tris(2-phenylpyridine)iridium (fac-(ppy)3Ir)-based polyphenyle…

Materials science010405 organic chemistryGeneral Chemical Engineeringchemistry.chemical_elementGeneral Chemistry010402 general chemistryPhotochemistry01 natural sciencesSmall moleculeArticle0104 chemical scienceslcsh:ChemistryBipyridinechemistry.chemical_compoundchemistrylcsh:QD1-999Excited stateDendrimerBathochromic shiftChelationIridiumPhosphorescenceACS Omega
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A black-box approach to the construction of metal-radical multispin systems and analysis of their magnetic properties

2020

An interaction of M(hfac)2 (M = Mn or Ni) with N-(bis(4,4,5,5-tetramethyl-3-oxido-1-oxyl-4,5-dihydro-1H-imidazol-2-yl)methylene)-2-methyl-propan-2-amine oxide (a nitronyl nitroxide diradical with theC[double bond, length as m-dash]N(O)-tert-Bu coupler) was investigated under various conditions. It was found that prolongation of reaction time caused transformation of the initial diradical into new diradicals with the uniqueC[double bond, length as m-dash]N-OH coupling unit and formation of binuclear Mn(ii) and Ni(ii) complexes, which were characterized by X-ray diffraction analysis. The resulting binuclear heterospin complexes have a complicated magnetic structure with six paramagnetic cente…

Inorganic ChemistryParamagnetismNitroxide mediated radical polymerizationCrystallographyMaterials scienceMagnetic structureDiradicalAb initio quantum chemistry methodsExchange interactionDensity functional theoryElectronic structureDalton Transactions
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Cruciform Electron Acceptors Based on Tetraindeno-Fused Spirofluorene

2017

Two cruciform tetraindenospirofluorene-based acceptors embedding carbonyl (Spiro-4O) and dicyanovinylene (Spiro-8CN) functionalities are synthesized in high yields. Single-crystal X-ray analysis reveals a one-dimensional π–π stacking arrangement for Spiro-4O, while Spiro-8CN adopts a unique two-dimensional isotropic π-interaction. Cyclic voltammetry suggests a high electron affinity of −3.76 eV for Spiro-8CN. Such a packing motif and low LUMO energy for Spiro-8CN are important for bulk electron transport.

chemistry.chemical_classification010405 organic chemistryStackingGeneral ChemistryElectron acceptor010402 general chemistryCondensed Matter Physics01 natural sciencesElectron transport chain0104 chemical sciencesCrystallographychemistryElectron affinity (data page)CruciformGeneral Materials ScienceCyclic voltammetryHOMO/LUMOCrystal Growth & Design
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Tuning the hole injection barrier in the intermolecular charge-transfer compoundDTBDT-F4TCNQ at metal interfaces

2014

Molecular monolayers of the charge-transfer salt dithienobenzodithiophene-tetrafluorotetracyanoquinodimethane (DTBDT-F${}_{4}$TCNQ) have been deposited on C(R$15\ifmmode\times\else\texttimes\fi{}3$)/W(110), Co/W(110), and hcp Co(0001) using molecular beam epitaxy in an ultrahigh vacuum. The integrity of the deposited molecules has been confirmed by scanning tunneling microscopy. Scanning tunneling spectroscopy has been used to determine the energetic positions of the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbital of acceptor and donor in the pure and in the mixed phase. The mixed charge transfer phase exhibits a new HOMO close to the Fermi edge depicting a charge tra…

Materials sciencebusiness.industryBand gapScanning tunneling spectroscopyBinding energyCondensed Matter PhysicsElementary chargeAcceptorElectronic Optical and Magnetic Materialslaw.inventionCrystallographylawOptoelectronicsMolecular orbitalScanning tunneling microscopebusinessHOMO/LUMOPhysical Review B
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Hexasubstituierte Benzolderivate mit ultrastarken Dipolmomenten

2016

Materials science02 engineering and technologyGeneral Medicine010402 general chemistry021001 nanoscience & nanotechnology0210 nano-technology01 natural sciences0104 chemical sciencesAngewandte Chemie
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The magnetic properties of ferrocene based macromolecules

1993

Abstract Magnetic susceptibility data for conjugatively linked biferrocenes and a methylene bridged ferrocene polymer are presented. In 9,10-di((2-ferrocenyl)vinyl)anthracene a rigid divinylanthracene bridge is connecting two ferrocene units, and the oxidation of both iron centers leads to an antiferromagnetic coupling. In contrast, ferromagnetic coupling between iron centers is indicated for 2,2'-cis,trans-di((2-ferrocenyl)vinyl)biphenyl, where a twist around the phenyl-phenyl bond in the divinylbiphenyl bridging molecule is likely to occur.

BiphenylAnthraceneStereochemistryMechanical EngineeringMetals and AlloysCondensed Matter PhysicsMagnetic susceptibilityElectronic Optical and Magnetic Materialschemistry.chemical_compoundCrystallographychemistryFerroceneFerromagnetismMechanics of MaterialsMaterials ChemistryMoleculeMethyleneMacromoleculeSynthetic Metals
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Breaking the semi-quinoid structure: spin-switching from strongly coupled singlet to polarized triplet state.

2014

2,7-TMPNO (4,5,9,10-tetramethoxypyrene-2,7-bis(tert-butylnitroxide)) was found to exist in semi-quinoid form with unprecedented strong intramolecular magnetic exchange interaction of 2 J/kB = 1185 K operating over a distance of 10 A. Structural transformations with the activation energy of ΔEeq = 949 K were observed by varying the temperature, from more quinoid structure at low temperature to more biradicaloid structure at higher temperature. Moreover, this molecule undergoes a transient spin transition from singlet to polarized triplet state upon photoexcitation revealed by TREPR spectroscopy. The spin Hamiltonian parameters were determined to be S = 1, g = 2.0065, D = -0.0112 cm(-1), and …

ChemistryOrganic ChemistrySpin transitionGeneral ChemistryMolecular physicsCatalysislaw.inventionPhotoexcitationlawComputational chemistryIntramolecular forceSinglet stateTriplet stateElectron paramagnetic resonanceSpin (physics)SpectroscopyChemistry (Weinheim an der Bergstrasse, Germany)
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Dicyanobenzothiadiazole Derivatives Possessing Switchable Dielectric Permittivities

2017

Benzothiadiazoles are important electron acceptors and are frequently employed as electron-deficient components of donor-acceptor polymers. We report the effect of nitrile functionalities on the reactivity, steric hindrance, optoelectronic properties, and dielectric permittivity in dicyanobenzothioadiazole (DCNBT). Dielectric spectroscopy in the bulk and in solution assisted by DFT-calculations revealed that these molecules can be engineered to engender maximum values of the dipole moment and of dielectric permittivity due to the strong electron-withdrawing effect of the nitrile groups. The self-assembly in the bulk was investigated by X-ray scattering performed on single crystals, fibers (…

chemistry.chemical_classificationMaterials scienceNitrileRelative permittivity02 engineering and technologyPolymerDielectric010402 general chemistry021001 nanoscience & nanotechnology01 natural sciences0104 chemical sciencesDielectric spectroscopyDipolechemistry.chemical_compoundchemistryChemical physicsLiquid crystalPhase (matter)Organic chemistryGeneral Materials Science0210 nano-technologyACS Applied Materials & Interfaces
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CCDC 1421613: Experimental Crystal Structure Determination

2016

Related Article: Jakob Wudarczyk, George Papamokos, Vasilis Margaritis, Dieter Schollmeyer, Felix Hinkel, Martin Baumgarten, George Floudas, Klaus Müllen|2016|Angew.Chem.,Int.Ed.|55|3220|doi:10.1002/anie.201508249

Space GroupCrystallographyCrystal SystemCrystal Structure45-Diamino-36-dibromophthalonitrileCell ParametersExperimental 3D Coordinates
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CCDC 1533973: Experimental Crystal Structure Determination

2017

Related Article: Jakob Wudarczyk, George Papamokos, Tomasz Marszalek, Thomas Nevolianis, Dieter Schollmeyer, Wojciech Pisula, George Floudas, Martin Baumgarten, and Klaus Müllen|2017|ACS Applied Materials and Interfaces|9|20527|doi:10.1021/acsami.7b03060

Space GroupCrystallography47-bis(13-thiazol-5-yl)-213-benzothiadiazole-56-dicarbonitrileCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1408336: Experimental Crystal Structure Determination

2017

Related Article: Debin Xia, Xin Guo, Manfred Wagner, Martin Baumgarten, Dieter Schollmeyer, Klaus Müllen|2017|Cryst.Growth Des.|17|2816|doi:10.1021/acs.cgd.7b00272

Space GroupCrystallographyCrystal SystemCrystal Structure33'99'-tetra-t-butyl-66'-spirobi[diindeno[12-b:2'1'-h]fluorene]-1212'1515'-tetrone unknown solvateCell ParametersExperimental 3D Coordinates
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CCDC 1816642: Experimental Crystal Structure Determination

2018

Related Article: Ben-Lin, Hu Ke Zhang, Cunbin An, Dieter Schollmeyer, Wojciech Pisula, Martin Baumgarten|2018|Angew.Chem.,Int.Ed.|57|12375|doi:10.1002/anie.201803230

Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters259121519-hexakis{[triisopropylsilyl]ethynyl}[125]thiadiazolo[34-i][125]thiadiazolo[3''4'':6'7']quinoxalino[2'3':910]phenanthro[45-abc]phenazineExperimental 3D Coordinates
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CCDC 1533972: Experimental Crystal Structure Determination

2017

Related Article: Jakob Wudarczyk, George Papamokos, Tomasz Marszalek, Thomas Nevolianis, Dieter Schollmeyer, Wojciech Pisula, George Floudas, Martin Baumgarten, and Klaus Müllen|2017|ACS Applied Materials and Interfaces|9|20527|doi:10.1021/acsami.7b03060

Space GroupCrystallographyCrystal SystemCrystal Structure47-bis(13-thiazol-2-yl)-213-benzothiadiazole-56-dicarbonitrileCell ParametersExperimental 3D Coordinates
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CCDC 1862382: Experimental Crystal Structure Determination

2019

Related Article: Kubandiran Kolanji, Lars Postulka, Bernd Wolf, Michael Lang, Dieter Schollmeyer, and Martin Baumgarten|2019|J.Org.Chem.|84|140|doi:10.1021/acs.joc.8b02499

Space GroupCrystallography48-dimethoxybenzo[12-b:45-b']bis(thiophene)Crystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1421614: Experimental Crystal Structure Determination

2016

Related Article: Jakob Wudarczyk, George Papamokos, Vasilis Margaritis, Dieter Schollmeyer, Felix Hinkel, Martin Baumgarten, George Floudas, Klaus Müllen|2016|Angew.Chem.,Int.Ed.|55|3220|doi:10.1002/anie.201508249

Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters56-Diaminobenzene-1234-tetracarbonitrile NN-dimethylformamide solvateExperimental 3D Coordinates
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CCDC 1862545: Experimental Crystal Structure Determination

2019

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters22'-[(48-dimethoxybenzo[12-b:45-b']bisthiene-26-diyl)bis(thiene-52-diyl)]bis(4455-tetramethyl-45-dihydro-1H-3lambda5-imidazole-13-diolate) diradicalExperimental 3D Coordinates
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CCDC 1421615: Experimental Crystal Structure Determination

2016

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters56-Diaminobenzene-1234-tetracarbonitrile tetrahydrofuran solvateExperimental 3D Coordinates
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CCDC 1862543: Experimental Crystal Structure Determination

2019

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters22'-(48-dimethoxybenzo[12-b:45-b']bisthiene-26-diyl)bis(4455-tetramethyl-3-oxo-45-dihydro-1H-3lambda5-imidazol-1-olate) diradicalExperimental 3D Coordinates
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CCDC 1857365: Experimental Crystal Structure Determination

2019

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Space GroupCrystallographyCrystal Systemmer-tris(26-difluoro-3-(5-(trimethylsilyl)pyridin-2-yl)pyridin-4-yl)-iridiumCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1408340: Experimental Crystal Structure Determination

2017

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameterstetraspiro{33'99'-tetra-t-butyl-1212'1515'-tetrahydro-66'-spirobi[diindeno[12-b:2'1'-h]fluorene]-129'':12'9''':159'''':15'9'''''-tetrakis(fluorene)} unknown solvateExperimental 3D Coordinates
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CCDC 1857364: Experimental Crystal Structure Determination

2019

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Space GroupCrystallographyfac-tris(26-difluoro-3-(5-(trimethylsilyl)pyridin-2-yl)pyridin-4-yl)-iridium dichloromethane solvateCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
researchProduct

CCDC 1862542: Experimental Crystal Structure Determination

2019

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Space GroupCrystallographyCrystal System22'-[(48-dimethoxybenzo[12-b:45-b']bisthiene-26-diyl)bis(thiene-52-diyl)]bis(13-bis{[t-butyl(dimethyl)silyl]oxy}-4455-tetramethylimidazolidine) dichloromethane solvateCrystal StructureCell ParametersExperimental 3D Coordinates
researchProduct

CCDC 1533971: Experimental Crystal Structure Determination

2017

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters47-bis(4-hexylthiophen-2-yl)-213-benzothiadiazole-56-dicarbonitrileExperimental 3D Coordinates
researchProduct

CCDC 1421617: Experimental Crystal Structure Determination

2016

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22-Dimethyl-23-dihydro-1H-benzimidazole-4567-tetracarbonitrile tetrahydrofuran solvateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 1533733: Experimental Crystal Structure Determination

2017

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters47-bis(thiophen-2-yl)-213-benzothiadiazole-56-dicarbonitrileExperimental 3D Coordinates
researchProduct

CCDC 1533970: Experimental Crystal Structure Determination

2017

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters47-dibromo-213-benzothiadiazole-56-dicarbonitrileExperimental 3D Coordinates
researchProduct

CCDC 1408347: Experimental Crystal Structure Determination

2017

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters22'2''2'''-(33'99'-tetra-t-butyl-66'-spirobi[diindeno[12-b:2'1'-h]fluorene]-1212'1515'-tetraylidene)tetrapropanedinitrile dichloromethane unknown solvateExperimental 3D Coordinates
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CCDC 1489370: Experimental Crystal Structure Determination

2017

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Space GroupCrystallography3-(4'-(5-(4-t-butylphenyl)-134-oxadiazol-2-yl)biphenyl-4-yl)-4-(4-(36-di-t-butyl-9H-carbazol-9-yl)phenyl)-25-diphenylcyclopenta-24-dien-1-one chloroform solvateCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
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CCDC 950752: Experimental Crystal Structure Determination

2014

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Space GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates(45910-tetramethoxypyrene-27-bis(t-butylnitroxide)) biradical
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CCDC 1948965: Experimental Crystal Structure Determination

2019

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Space GroupCrystallographytris(13-bis(4-((tri-isopropylsilyl)ethynyl)phenyl)-13-dihydro-2H-benzimidazol-2-ylidene)-iridium dichloromethane unknown solvateCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
researchProduct

CCDC 1862544: Experimental Crystal Structure Determination

2019

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Space GroupCrystallographyCrystal SystemCrystal Structure22'-(48-dimethoxybenzo[12-b:45-b']bis(thiene-26-diyl))bis(4455-tetramethyl-45-dihydro-1H-imidazol-1-olate) diradicalCell ParametersExperimental 3D Coordinates
researchProduct

CCDC 1816643: Experimental Crystal Structure Determination

2018

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Space GroupCrystallography1117232941475359-octakis((2-[triisopropylsilyl]ethynyl))-2050-dithia-3715192125333745495155-dodecaazaheptadecacyclo[37.21.2.2927.0238.0436.0634.0832.01426.01624.01822.04362.04456.04654.04852.05761.01364.03163]tetrahexaconta-1(61)246(34)79(64)1012141618212325272931(63)32353739(62)40424446485153555759-hentriacontaene tetrahydrofuran solvateCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
researchProduct

CCDC 1814647: Experimental Crystal Structure Determination

2018

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters47-dibromo-22-diheptyl-13-dimethyl-23-dihydro-1H-benzimidazole-56-dicarbonitrileExperimental 3D Coordinates
researchProduct

CCDC 1533734: Experimental Crystal Structure Determination

2017

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters47-bis[(4-t-butylphenyl)ethynyl]-213-benzothiadiazole-56-dicarbonitrileExperimental 3D Coordinates
researchProduct

CCDC 1848515: Experimental Crystal Structure Determination

2018

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Space GroupCrystallography11'-spiro-bi-(581114-tetra-t-butyl-1H-tetrabenzo[efhiklno]fluoreno[3456-qrabc]coronene) n-pentane solvateCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates
researchProduct

CCDC 1893173: Experimental Crystal Structure Determination

2020

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Space GroupCrystallographyCrystal System311-bis(4-t-butylphenyl)-614-dimesityldibenzo[hist]ovaleneCrystal StructureCell ParametersExperimental 3D Coordinates
researchProduct

CCDC 1814646: Experimental Crystal Structure Determination

2018

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters47-dibromo-22-diheptyl-23-dihydro-1H-benzimidazole-56-dicarbonitrileExperimental 3D Coordinates
researchProduct

CCDC 1421616: Experimental Crystal Structure Determination

2016

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Space GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates47-Dibromo-22-dimethyl-23-dihydro-1H-benzimidazole-56-dicarbonitrile
researchProduct

CCDC 1814648: Experimental Crystal Structure Determination

2018

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Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters47-bis(4-chlorophenyl)-22-diheptyl-13-dimethyl-23-dihydro-1H-benzimidazole-56-dicarbonitrileExperimental 3D Coordinates
researchProduct

CCDC 1010016: Experimental Crystal Structure Determination

2015

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Space GroupCrystallographyCrystal SystemCrystal Structuretetrakis(4-(2345-tetraphenyl)phenyl)phosphonium tetrafluoroborate dichloromethane solvate tetrahydrateCell ParametersExperimental 3D Coordinates
researchProduct