@article{KarKoerzdoerfer2018, author = {Kar, M. and K{\"o}rzd{\"o}rfer, Thomas}, title = {Computational screening of methylammonium based halide perovskites with bandgaps suitable for perovskite-perovskite tandem solar cells}, series = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr}, volume = {149}, journal = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr}, number = {21}, publisher = {American Institute of Physics}, address = {Melville}, issn = {0021-9606}, doi = {10.1063/1.5037535}, pages = {7}, year = {2018}, abstract = {We aim to find homovalent alternatives for lead and iodine in CH3NH3PbI3 perovskites that show bandgaps suitable for building novel perovskite-perovskite tandem solar cells. To this end, we employ a computational screening for materials with a bandgap between 1.0 eV and 1.9 eV, using density functional theory calculations at the Perdew-Burke-Ernzerhof and Heyd-Scuseria-Ernzerhof levels of theory. The room-temperature stability of the materials and their phases that satisfy the bandgap criteria is evaluated based on the empirical Goldschmidt tolerance factor. In total, our screening procedure covers 30 different perovskite structures in three phases (orthorhombic, cubic, tetragonal) each. We find 9 materials that are predicted to be stable at room temperature and to have bandgaps in an energy range suitable for application in tandem solar cells. Published by AIP Publishing.}, language = {en} } @misc{KoerzdoerferBredas2014, author = {K{\"o}rzd{\"o}rfer, Thomas and Bredas, Jean-Luc}, title = {Organic electronic materials: recent advances in the DFT description of the ground and excited states using tuned range-separated hybrid functionals}, series = {Accounts of chemical research}, volume = {47}, journal = {Accounts of chemical research}, number = {11}, publisher = {American Chemical Society}, address = {Washington}, issn = {0001-4842}, doi = {10.1021/ar500021t}, pages = {3284 -- 3291}, year = {2014}, abstract = {CONSPECTUS: Density functional theory (DFT) and its time-dependent extension (TD-DFT) are powerful tools enabling the theoretical prediction of the ground- and excited-state properties of organic electronic materials with reasonable accuracy at affordable computational costs. Due to their excellent accuracy-to-numerical-costs ratio, semilocal and global hybrid functionals such as B3LYP have become the workhorse for geometry optimizations and the prediction of vibrational spectra in modern theoretical organic chemistry. Despite the overwhelming success of these out-of-the-box functionals for such applications, the computational treatment of electronic and structural properties that are of particular interest in organic electronic materials sometimes reveals severe and qualitative failures of such functionals. Important examples include the overestimation of conjugation, torsional barriers, and electronic coupling as well as the underestimation of bond-length alternations or excited-state energies in low-band-gap polymers. In this Account, we highlight how these failures can be traced back to the delocalization error inherent to semilocal and global hybrid functionals, which leads to the spurious delocalization of electron densities and an overestimation of conjugation. The delocalization error for systems and functionals of interest can be quantified by allowing for fractional occupation of the highest occupied molecular orbital. It can be minimized by using long-range corrected hybrid functionals and a nonempirical tuning procedure for the range-separation parameter. We then review the benefits and drawbacks of using tuned long-range corrected hybrid functionals for the description of the ground and excited states of pi-conjugated systems. In particular, we show that this approach provides for robust and efficient means of characterizing the electronic couplings in organic mixed-valence systems, for the calculation of accurate torsional barriers at the polymer limit, and for the reliable prediction of the optical absorption spectrum of low-band-gap polymers. We also explain why the use of standard, out-of-the-box range-separation parameters is not recommended for the DFT and/or TD-DFT description of the ground and excited states of extended, pi-conjugated systems. Finally, we highlight a severe drawback of tuned range-separated hybrid functionals by discussing the example of the calculation of bond-length alternation in polyacetylene, which leads us to point out the challenges for future developments in this field.}, language = {en} } @article{SuttonKoerzdoerferGrayetal.2014, author = {Sutton, Christopher and K{\"o}rzd{\"o}rfer, Thomas and Gray, Matthew T. and Brunsfeld, Max and Parrish, Robert M. and Sherrill, C. David and Sears, John S. and Bredas, Jean-Luc}, title = {Accurate description of torsion potentials in conjugated polymers using density functionals with reduced self-interaction error}, series = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr}, volume = {140}, journal = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr}, number = {5}, publisher = {American Institute of Physics}, address = {Melville}, issn = {0021-9606}, doi = {10.1063/1.4863218}, pages = {9}, year = {2014}, abstract = {We investigate the torsion potentials in two prototypical pi-conjugated polymers, polyacetylene and polydiacetylene, as a function of chain length using different flavors of density functional theory. Our study provides a quantitative analysis of the delocalization error in standard semilocal and hybrid density functionals and demonstrates how it can influence structural and thermodynamic properties. The delocalization error is quantified by evaluating the many-electron self-interaction error (MESIE) for fractional electron numbers, which allows us to establish a direct connection between the MESIE and the error in the torsion barriers. The use of non-empirically tuned long-range corrected hybrid functionals results in a very significant reduction of the MESIE and leads to an improved description of torsion barrier heights. In addition, we demonstrate how our analysis allows the determination of the effective conjugation length in polyacetylene and polydiacetylene chains.}, language = {en} } @article{MaromKoerzdoerferRenetal.2014, author = {Marom, Noa and K{\"o}rzd{\"o}rfer, Thomas and Ren, Xinguo and Tkatchenko, Alexandre and Chelikowsky, James R.}, title = {Size effects in the interface level alignment of dye-Sensitized TiO2 clusters}, series = {The journal of physical chemistry letters}, volume = {5}, journal = {The journal of physical chemistry letters}, number = {14}, publisher = {American Chemical Society}, address = {Washington}, issn = {1948-7185}, doi = {10.1021/jz5008356}, pages = {2395 -- 2401}, year = {2014}, abstract = {The efficiency of dye-sensitized solar cells (DSCs) depends critically on the electronic structure of the interfaces in the active region. We employ recently developed dispersion-inclusive density functional theory (DFT) and GW methods to study the electronic structure of TiO2 clusters sensitized with catechol molecules. We show that the energy level alignment at the dye-TiO2 interface is the result of an intricate interplay of quantum size effects and dynamic screening effects and that it may be manipulated by nanostructuring and functionalizing the TiO2. We demonstrate that the energy difference between the catechol LUMO and the TiO2 LUMO, which is associated with the injection loss in DSCs, may be reduced significantly by reducing the dimensions of nanostructured TiO2 and by functionalizing the TiO2 with wide-gap moieties, which contribute additional screening but do not interact strongly with the frontier orbitals of the TiO2 and the dye. Precise control of the electronic structure may be achieved via "interface engineering" in functional nanostructures.}, language = {en} } @article{KoerzdoerferParrishMarometal.2012, author = {K{\"o}rzd{\"o}rfer, Thomas and Parrish, Robert M. and Marom, Noa and Sears, John S. and Sherrill, C. David and Bredas, Jean-Luc}, title = {Assessment of the performance of tuned range-separated hybrid density functionals in predicting accurate quasiparticle spectra}, series = {Physical review : B, Condensed matter and materials physics}, volume = {86}, journal = {Physical review : B, Condensed matter and materials physics}, number = {20}, publisher = {American Physical Society}, address = {College Park}, issn = {1098-0121}, doi = {10.1103/PhysRevB.86.205110}, pages = {9}, year = {2012}, abstract = {Long-range corrected hybrid functionals that employ a nonempirically tuned range-separation parameter have been demonstrated to yield accurate ionization potentials and fundamental gaps for a wide range of finite systems. Here, we address the question of whether this high level of accuracy is limited to the highest occupied/lowest unoccupied energy levels to which the range-separation parameter is tuned or whether it is retained for the entire valence spectrum. We examine several pi-conjugated molecules and find that orbitals of a different character and symmetry require significantly different range-separation parameters and fractions of exact exchange. This imbalanced treatment of orbitals of a different nature biases the resulting eigenvalue spectra. Thus, the existing schemes for the tuning of range-separated hybrid functionals, while providing for good agreement between the highest occupied energy level and the first ionization potential, do not achieve accuracy comparable to reliable G(0)W(0) computations for the entire quasiparticle spectrum.}, language = {en} } @article{SuttonKoerzdoerferCoropceanuetal.2014, author = {Sutton, Christopher and K{\"o}rzd{\"o}rfer, Thomas and Coropceanu, Veaceslav and Bredas, Jean-Luc}, title = {Toward a robust quantum-chemical description of organic mixed-valence systems}, series = {The journal of physical chemistry : C, Nanomaterials and interfaces}, volume = {118}, journal = {The journal of physical chemistry : C, Nanomaterials and interfaces}, number = {8}, publisher = {American Chemical Society}, address = {Washington}, issn = {1932-7447}, doi = {10.1021/jp410461v}, pages = {3925 -- 3934}, year = {2014}, abstract = {The electronic coupling between redox sites in mixed-valence systems has attracted the interest of the chemistry community for a long time. Many computational studies have focused on trying to determine its magnitude as a function of the nature of the redox sites and of the bridge(s) between them. However, in most instances, the quantum-chemical methodologies that have been employed suffer from intrinsic errors that lead to either an overlocalized or an overdelocalized character of the electronic structure. These deficiencies prevent an accurate depiction of the degree of charge (de)localization in the system and, as a result, of the extent of electronic coupling. Here we use nonempirically tuned long-range corrected density functional theory and show that it provides a robust, efficient approach to characterize organic mixed-valence systems. We first demonstrate the performance of this approach via a study of representative Robin-Day class-II (localized) and class-III (delocalized) complexes. We then examine a borderline class-II/class-III complex, which had proven difficult to describe accurately with standard density functional theory and Hartree-Fock methods.}, language = {en} } @article{MaromCarusoRenetal.2012, author = {Marom, Noa and Caruso, Fabio and Ren, Xinguo and Hofmann, Oliver T. and K{\"o}rzd{\"o}rfer, Thomas and Chelikowsky, James R. and Rubio, Angel and Scheffler, Matthias and Rinke, Patrick}, title = {Benchmark of GW methods for azabenzenes}, series = {Physical review : B, Condensed matter and materials physics}, volume = {86}, journal = {Physical review : B, Condensed matter and materials physics}, number = {24}, publisher = {American Physical Society}, address = {College Park}, issn = {1098-0121}, doi = {10.1103/PhysRevB.86.245127}, pages = {16}, year = {2012}, abstract = {Many-body perturbation theory in the GW approximation is a useful method for describing electronic properties associated with charged excitations. A hierarchy of GW methods exists, starting from non-self-consistent G(0)W(0), through partial self-consistency in the eigenvalues and in the Green's function (scGW(0)), to fully self-consistent GW (scGW). Here, we assess the performance of these methods for benzene, pyridine, and the diazines. The quasiparticle spectra are compared to photoemission spectroscopy (PES) experiments with respect to all measured particle removal energies and the ordering of the frontier orbitals. We find that the accuracy of the calculated spectra does not match the expectations based on their level of self-consistency. In particular, for certain starting points G(0)W(0) and scGW(0) provide spectra in better agreement with the PES than scGW.}, language = {en} } @article{KoerzdoerferParrishSearsetal.2012, author = {K{\"o}rzd{\"o}rfer, Thomas and Parrish, Robert M. and Sears, John S. and Sherrill, C. David and Bredas, Jean-Luc}, title = {On the relationship between bond-length alternation and many-electron self-interaction error}, series = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr}, volume = {137}, journal = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr}, number = {12}, publisher = {American Institute of Physics}, address = {Melville}, issn = {0021-9606}, doi = {10.1063/1.4752431}, pages = {8}, year = {2012}, abstract = {Predicting accurate bond-length alternations (BLAs) in long conjugated molecular chains has been a major challenge for electronic-structure theory for many decades. While Hartree-Fock (HF) overestimates BLA significantly, second-order perturbation theory and commonly used density functional theory (DFT) approaches typically underestimate it. Here, we discuss how this failure is related to the many-electron self-interaction error (MSIE), which is inherent to both HF and DFT approaches. We use tuned long-range corrected hybrids to minimize the MSIE for a series of polyenes. The key result is that the minimization of the MSIE alone does not yield accurate BLAs. On the other hand, if the range-separation parameter is tuned to yield accurate BLAs, we obtain a significant MSIE that grows with chain length. Our findings demonstrate that reducing the MSIE is one but not the only important aspect necessary to obtain accurate BLAs from density functional theory.}, language = {en} } @article{GallandiKoerzdoerfer2015, author = {Gallandi, Lukas and K{\"o}rzd{\"o}rfer, Thomas}, title = {Long-Range Corrected DFT Meets GW: Vibrationally Resolved Photoelectron Spectra from First Principles}, series = {Journal of chemical theory and computation}, volume = {11}, journal = {Journal of chemical theory and computation}, number = {11}, publisher = {American Chemical Society}, address = {Washington}, issn = {1549-9618}, doi = {10.1021/acs.jctc.5b00820}, pages = {5391 -- 5400}, year = {2015}, abstract = {We propose an entirely nonempirical and computationally efficient scheme to calculate highly reliable vibrationally resolved photoelectron spectra for molecules from first principles. To this end, we combine nonempirically tuned long-range corrected hybrid functionals with non-self-consistent many-body perturbation theory in the G(0)W(0) approximation and a Franck-Condon multimode analysis based on DFT-calculated frequencies. The vibrational analysis allows for a direct comparison of the GW-calculated spectra to gas-phase ultraviolet photoelectron measurements of neutral and anionic molecules, respectively. Direct comparison of the calculated peak maxima with experiment yields mean absolute errors below 0.1 eV for ionization potentials, electron affinities, and fundamental gaps, clearly outperforming commonly used G(0)W(0) approaches at similar numerical costs.}, language = {en} } @article{SunRynoZhongetal.2016, author = {Sun, Haitao and Ryno, Sean and Zhong, Cheng and Ravva, Mahesh Kumar and Sun, Zhenrong and K{\"o}rzd{\"o}rfer, Thomas and Bredas, Jean-Luc}, title = {Ionization Energies, Electron Affinities, and Polarization Energies of Organic Molecular Crystals: Quantitative Estimations from a Polarizable Continuum Model (PCM)-Tuned Range-Separated Density Functional Approach}, series = {Journal of chemical theory and computation}, volume = {12}, journal = {Journal of chemical theory and computation}, publisher = {American Chemical Society}, address = {Washington}, issn = {1549-9618}, doi = {10.1021/acs.jctc.6b00225}, pages = {2906 -- 2916}, year = {2016}, abstract = {We propose a new methodology for the first principles description of the electronic properties relevant for charge transport in organic molecular crystals. This methodology, which is based on the combination of a nonempirical, optimally tuned range separated hybrid functional with the polarizable continuum model, is applied to a series of eight representative molecular semiconductor crystals. We show that it provides ionization energies, electron affinities, and transport gaps in very good agreement with experimental values, as well as with the results of many-body perturbation theory-within the GW approximation at a fraction of the computational cost. Hence, this approach represents an easily applicable and computationally efficient tool to estimate the gas-to crystal phase shifts of the frontier-orbital quasiparticle energies in organic electronic materials.}, language = {en} } @article{BoisKoerzdoerfer2016, author = {Bois, Juliana and K{\"o}rzd{\"o}rfer, Thomas}, title = {0 How Bond Length Alternation and Thermal Disorder Affect the Optical Excitation Energies of pi-Conjugated Chains: A Combined Density Functional Theory and Molecular Dynamics Study}, series = {Journal of chemical theory and computation}, volume = {12}, journal = {Journal of chemical theory and computation}, publisher = {American Chemical Society}, address = {Washington}, issn = {1549-9618}, doi = {10.1021/acs.jctc.5b01070}, pages = {1872 -- 1882}, year = {2016}, abstract = {We dissect the sources of error leading to inaccuracies in the description of the geometry and optical excitation energies of pi-conjugated polymers. While the ground-state bond length alternation is shown to be badly reproduced by standard functionals, the recently adapted functionals PBEh* and omega PBE* as well as the double hybrid functional XYGJ-OS manage to replicate results obtained at the CCSD(T) level. By analysis of the bond length alternation in the excited state, a sensitive dependence of the exciton localization on the long-range behavior of the functional and the amount of Hartree-Fock exchange present is shown. Introducing thermal disorder through molecular dynamics simulations allows the consideration of a range of thermally accessible configurations of each oligomer, including trans to cis rotations, which break the conjugation of the backbone. Thermal disorder has a considerable effect when combined with functionals that overestimate the delocalization of the excitation, such as B3LYP. For functionals with a larger amount of exact exchange such as our PBEh* and omega PBE*, however, the effect is small, as excitations are often localized enough to fit between twists in the chain.}, language = {en} } @article{GallandiMaromRinkeetal.2016, author = {Gallandi, Lukas and Marom, Noa and Rinke, Patrick and K{\"o}rzd{\"o}rfer, Thomas}, title = {Accurate Ionization Potentials and Electron Affinities of Acceptor Molecules II: Non-Empirically Tuned Long-Range Corrected Hybrid Functionals}, series = {Journal of chemical theory and computation}, volume = {12}, journal = {Journal of chemical theory and computation}, publisher = {American Chemical Society}, address = {Washington}, issn = {1549-9618}, doi = {10.1021/acs.jctc.5b00873}, pages = {605 -- 614}, year = {2016}, abstract = {The performance of non-empirically tuned long-range corrected hybrid functionals for the prediction of vertical ionization potentials (IPs) and electron affinities (EAs) is assessed for a set of 24 organic acceptor molecules. Basis set extrapolated coupled cluster singles, doubles, and perturbative triples [CCSD(T)] calculations serve as a reference for this study. Compared to standard exchange-correlation functionals, tuned long-range corrected hybrid functionals produce highly reliable results for vertical IPs and EAs, yielding mean absolute errors on par with computationally more demanding GW calculations. In particular, it is demonstrated that long-range corrected hybrid functionals serve as ideal starting points for non-self-consistent GW calculations.}, language = {en} } @article{KnightWangGallandietal.2016, author = {Knight, Joseph W. and Wang, Xiaopeng and Gallandi, Lukas and Dolgounitcheva, Olga and Ren, Xinguo and Ortiz, J. Vincent and Rinke, Patrick and K{\"o}rzd{\"o}rfer, Thomas and Marom, Noa}, title = {Accurate Ionization Potentials and Electron Affinities of Acceptor Molecules III: A Benchmark of GW Methods}, series = {Journal of chemical theory and computation}, volume = {12}, journal = {Journal of chemical theory and computation}, publisher = {American Chemical Society}, address = {Washington}, issn = {1549-9618}, doi = {10.1021/acs.jctc.5b00871}, pages = {615 -- 626}, year = {2016}, abstract = {The performance of different GW methods is assessed for a set of 24 organic acceptors. Errors are evaluated with respect to coupled cluster singles, doubles, and perturbative triples [CCSD(T)] reference data for the vertical ionization potentials (IPs) and electron affinities (EAs), extrapolated to the complete basis set limit. Additional comparisons are made to experimental data, where available. We consider fully self-consistent GW (scGW), partial self-consistency in the Green's function (scGW0), non-self-consistent G0W0 based on several mean-field starting points, and a "beyond GW" second-order screened exchange (SOSEX) correction to G0W0. We also describe the implementation of the self-consistent Coulomb hole with screened exchange method (COHSEX), which serves as one of the mean-field starting points. The best performers overall are G0W0+SOSEX and G0W0 based on an IP-tuned long-range corrected hybrid functional with the former being more accurate for EAs and the latter for IPs. Both provide a balanced treatment of localized vs delocalized states and valence spectra in good agreement with photoemission spectroscopy (PES) experiments.}, language = {en} } @unpublished{MegowKoerzdoerferRengeretal.2015, author = {Megow, J{\"o}rg and K{\"o}rzd{\"o}rfer, Thomas and Renger, Thomas and Sparenberg, Mino and Blumstengel, Sylke and May, Volkhard}, title = {Reply to "Comment on 'Calculating Optical Absorption Spectra of Thin Polycrystalline Organic Films: Structural Disorder and Site-Dependent van der Waals Interaction"}, series = {The journal of physical chemistry : C, Nanomaterials and interfaces}, volume = {119}, journal = {The journal of physical chemistry : C, Nanomaterials and interfaces}, number = {32}, publisher = {American Chemical Society}, address = {Washington}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.5b05536}, pages = {18818 -- 18820}, year = {2015}, language = {en} } @article{MegowKoerzdoerferRengeretal.2015, author = {Megow, J{\"o}rg and K{\"o}rzd{\"o}rfer, Thomas and Renger, Thomas and Sparenberg, Mino and Blumstengel, Sylke and Henneberger, Fritz and May, Volkhard}, title = {Calculating Optical Absorption Spectra of Thin Polycrystalline Organic Films: Structural Disorder and Site-Dependent van der Waals Interaction}, series = {The journal of physical chemistry : C, Nanomaterials and interfaces}, volume = {119}, journal = {The journal of physical chemistry : C, Nanomaterials and interfaces}, number = {10}, publisher = {American Chemical Society}, address = {Washington}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.5b01587}, pages = {5747 -- 5751}, year = {2015}, abstract = {We propose a new approach for calculating the change of the absorption spectrum of a molecule when moved from the gas phase to a crystalline morphology. The so-called gas-to-crystal shift Delta epsilon(m) is mainly caused by dispersion effects and depends sensitively on the molecules specific position in the nanoscopic setting. Using an extended dipole approximation, we are able to divide Delta epsilon(m)= -QW(m) in two factors, where Q depends only on the molecular species and accounts for all nonresonant electronic transitions contributing to the dispersion while W-m is a geometry factor expressing the site dependence of the shift in a given molecular structure. The ability of our approach to predict absorption spectra is demonstrated using the example of polycrystalline films of 3,4,9,10-perylenetetracarboxylic diimide (PTCDI).}, language = {en} } @article{BaierMetznerKoerzdoerferetal.2014, author = {Baier, Heiko and Metzner, Philipp and K{\"o}rzd{\"o}rfer, Thomas and Kelling, Alexandra and Holdt, Hans-J{\"u}rgen}, title = {Efficient palladium(II) precatalysts bearing 4,5-dicyanoimidazol-2-ylidene for the Mizoroki-Heck reaction}, series = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, journal = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, number = {18}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-1948}, doi = {10.1002/ejic.201402040}, pages = {2952 -- 2960}, year = {2014}, abstract = {The new N-heterocyclic carbene (NHC) complex [PdCl2{(CN)(2)IMes}(PPh3)] (2) ({(CN)(2)IMes}: 4,5-dicyano-1,3-dimesitylimidazol-2-ylidene) and the NHC palladacycle [PdCl(dmba){(CN)(2)IMes}] (3) (dmba: N,N-dimethylbenzylamine) have been synthesized by thermolysis of 4,5-dicyano-1,3-dimesityl-2-(pentafluorophenyl) imidazoline (1) in the presence of suitable palladium(II) precursors. The acyclic complex 2 was formed by ligand exchange using the mononuclear precursor [PdCl2(PPh3)(2)] and the palladacycle 3 was formed by cleavage of the dinuclear chloro-bridged precursor [Pd(mu-Cl)(dmba)](2). The new NHC precursor 1-benzyl-4,5-dicyano-2-(pentafluorophenyl)-3-picolylimidazoline (5) was formed by condensation of pentafluorobenzaldehyde with N-benzyl-N'-picolyldiaminomaleonitrile (4). The NHC palladacycle [PdCl2{(CN)(2)IBzPic}] (6) ({(CN)(2)IBzPic}: 1-benzyl-4,5-dicyano-3-picolylimidazol-2-ylidene) was prepared by in situ thermolysis of 5 in the presence of [PdCl2(PhCN)(2)]. The three palladium(II) complexes were characterized by NMR and IR spectroscopy, mass spectrometry and elemental analysis. In addition, the molecular structures of 2 and 3 were determined by X-ray diffraction. The pi-acidity of (CN)(2)IBzPic was compared with (CN)(2)IMes and perviously reported pi-acidic imidazol-2-ylidenes by NBO analysis. The Mizoroki-Heck (MH) reactions of various aryl halides with n-butyl acrylate were performed in the presence of complexes 2, 3 and 6. The new precatalysts showed high activity in the MH reactions giving good-to-excellent product yields with 0.1 mol-\% pre-catalyst. The nature of the catalytically active species of 2, 3 and 6 was investigated by poisoning experiments with mercury and transmission electron microscopy. It was found that palladium nanoparticles formed from the precatalysts were involved in the catalytic process.}, language = {en} } @article{AstSchwarzeMuelleretal.2013, author = {Ast, Sandra and Schwarze, Thomas and M{\"u}ller, Holger and Sukhanov, Aleksey and Michaelis, Stefanie and Wegener, Joachim and Wolfbeis, Otto S. and K{\"o}rzd{\"o}rfer, Thomas and D{\"u}rkop, Axel and Holdt, Hans-J{\"u}rgen}, title = {A highly K+-Selective Phenylaza-[18]crown-6-Lariat-Ether-Based Fluoroionophore and its application in the sensing of K+ Ions with an optical sensor film and in cells}, series = {Chemistry - a European journal}, volume = {19}, journal = {Chemistry - a European journal}, number = {44}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0947-6539}, doi = {10.1002/chem.201302350}, pages = {14911 -- 14917}, year = {2013}, abstract = {Herein, we report the synthesis of two phenylaza-[18]crown-6 lariat ethers with a coumarin fluorophore (1 and 2) and we reveal that compound 1 is an excellent probe for K+ ions under simulated physiological conditions. The presence of a 2-methoxyethoxy lariat group at the ortho position of the anilino moiety is crucial to the substantially increased stability of compounds 1 and 2 over their lariat-free phenylaza-[18] crown-6 ether analogues. Probe 1 shows a high K+/Na+ selectivity and a 2.5-fold fluorescence enhancement was observed in the presence of 100 mm K+ ions. A fluorescent membrane sensor, which was prepared by incorporating probe 1 into a hydrogel, showed a fully reversible response, a response time of 150 s, and a signal change of 7.8\% per 1 mm K+ within the range 1-10 mm K+. The membrane was easily fabricated (only a single sensing layer on a solid polyester support), yet no leaching was observed. Moreover, compound 1 rapidly permeated into cells, was cytocompatible, and was suitable for the fluorescent imaging of K+ ions on both the extracellular and intracellular levels.}, language = {en} } @article{KellerRackwitzCauetetal.2014, author = {Keller, Adrian and Rackwitz, Jenny and Cauet, Emilie and Lievin, Jacques and K{\"o}rzd{\"o}rfer, Thomas and Rotaru, Alexandru and Gothelf, Kurt V. and Besenbacher, Flemming and Bald, Ilko}, title = {Sequence dependence of electron-induced DNA strand breakage revealed by DNA nanoarrays}, series = {Scientific reports}, volume = {4}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/srep07391}, pages = {6}, year = {2014}, language = {en} } @article{XiongWłodarczykGallandietal.2018, author = {Xiong, Tao and Włodarczyk, Radosław Stanisław and Gallandi, Lukas and K{\"o}rzd{\"o}rfer, Thomas and Saalfrank, Peter}, title = {Vibrationally resolved photoelectron spectra of lower diamondoids}, series = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistry}, volume = {148}, journal = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistry}, number = {4}, publisher = {American Institute of Physics}, address = {Melville}, issn = {0021-9606}, doi = {10.1063/1.5012131}, pages = {9}, year = {2018}, abstract = {Vibrationally resolved lowest-energy bands of the photoelectron spectra (PES) of adamantane, diamantane, and urotropine were simulated by a time-dependent correlation function approach within the harmonic approximation. Geometries and normal modes for neutral and cationic molecules were obtained from B3LYP hybrid density functional theory (DFT). It is shown that the simulated spectra reproduce the experimentally observed vibrational finestructure (or its absence) quite well. Origins of the finestructure are discussed and related to recurrences of autocorrelation functions and dominant vibrations. Remaining quantitative and qualitative errors of the DFT-derived PES spectra refer to (i) an overall redshift by ∼0.5 eV and (ii) the absence of satellites in the high-energy region of the spectra. The former error is shown to be due to the neglect of many-body corrections to ordinary Kohn-Sham methods, while the latter has been argued to be due to electron-nuclear couplings beyond the Born-Oppenheimer approximation [Gali et al., Nat. Commun. 7, 11327 (2016)].}, language = {en} } @article{AbouserieZehbeMetzneretal.2017, author = {Abouserie, Ahed and Zehbe, Kerstin and Metzner, Philipp and Kelling, Alexandra and G{\"u}nter, Christina and Schilde, Uwe and Strauch, Peter and K{\"o}rzd{\"o}rfer, Thomas and Taubert, Andreas}, title = {Alkylpyridinium Tetrahalidometallate Ionic Liquids and Ionic Liquid Crystals: Insights into the Origin of Their Phase Behavior}, series = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, journal = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-1948}, doi = {10.1002/ejic.201700826}, pages = {5640 -- 5649}, year = {2017}, abstract = {Six N-alkylpyridinium salts [CnPy](2)[MCl4] (n = 4 or 12 and M = Co, Cu, Zn) were synthesized, and their structure and thermal properties were studied. The [C4Py](2)[MCl4] compounds are monoclinic and crystallize in the space group P2(1)/n. The crystals of the longer chain analogues [C12Py](2)[MCl4] are triclinic and crystallize in the space group P (1) over bar. Above the melting temperature, all compounds are ionic liquids (ILs). The derivatives with the longer C12 chain exhibit liquid crystallinity and the shorter chain compounds only show a melting transition. Consistent with single-crystal analysis, electron paramagnetic resonance spectroscopy suggests that the [CuCl4](2-) ions in the Cu-based ILs have a distorted tetrahedral geometry.}, language = {en} } @article{AbouserieZehbeMetzneretal.2017, author = {Abouserie, Ahed and Zehbe, Kerstin and Metzner, Philipp and Kelling, Alexandra and G{\"u}nter, Christina and Schilde, Uwe and Strauch, Peter and K{\"o}rzd{\"o}rfer, Thomas and Taubert, Andreas}, title = {Alkylpyridinium Tetrahalidometallate Ionic Liquids and Ionic Liquid Crystals: Insights into the Origin of Their Phase Behavior}, series = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, journal = {European journal of inorganic chemistry : a journal of ChemPubSoc Europe}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-1948}, doi = {10.1002/ejic.201700826}, pages = {5640 -- 5649}, year = {2017}, abstract = {Six N-alkylpyridinium salts [CnPy](2)[MCl4] (n = 4 or 12 and M = Co, Cu, Zn) were synthesized, and their structure and thermal properties were studied. The [C4Py](2)[MCl4] compounds are monoclinic and crystallize in the space group P2(1)/n. The crystals of the longer chain analogues [C12Py](2)[MCl4] are triclinic and crystallize in the space group P (1) over bar. Above the melting temperature, all compounds are ionic liquids (ILs). The derivatives with the longer C12 chain exhibit liquid crystallinity and the shorter chain compounds only show a melting transition. Consistent with single-crystal analysis, electron paramagnetic resonance spectroscopy suggests that the [CuCl4](2-) ions in the Cu-based ILs have a distorted tetrahedral geometry.}, language = {en} } @article{KarKoerzdoerfer2020, author = {Kar, Manaswita and K{\"o}rzd{\"o}rfer, Thomas}, title = {Computational high throughput screening of inorganic cation based halide perovskites for perovskite only tandem solar cells}, series = {Materials Research Express}, volume = {7}, journal = {Materials Research Express}, number = {5}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {2053-1591}, doi = {10.1088/2053-1591/ab8c0d}, pages = {1 -- 10}, year = {2020}, abstract = {We search for homovalent alternatives for A, B, and X-ions in ABX(3) type inorganic halide perovskites suitable for tandem solar cell applications. We replace the conventional A-site organic cation CH3NH3, by 3 inorganic cations, Cs, K, and Rb, and the B site consists of metals; Cd, Hg, Ge, Pb, and Sn This work is built on our previous high throughput screening of hybrid perovskite materials (Kar et al 2018 J. Chem. Phys. 149, 214701). By performing a systematic screening study using Density Functional Theory (DFT) methods, we found 11 suitable candidates; 2 Cs-based, 3 K-based and 6 Rb-based that are suitable for tandem solar cell applications.}, language = {en} } @article{BalischewskiChoiBehrensetal.2021, author = {Balischewski, Christian and Choi, Hyung-Seok and Behrens, Karsten and Beqiraj, Alkit and K{\"o}rzd{\"o}rfer, Thomas and Gessner, Andre and Wedel, Armin and Taubert, Andreas}, title = {Metal sulfide nanoparticle synthesis with ionic liquids state of the art and future perspectives}, series = {ChemistryOpen}, volume = {10}, journal = {ChemistryOpen}, number = {2}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {2191-1363}, doi = {10.1002/open.202000357}, pages = {272 -- 295}, year = {2021}, abstract = {Metal sulfides are among the most promising materials for a wide variety of technologically relevant applications ranging from energy to environment and beyond. Incidentally, ionic liquids (ILs) have been among the top research subjects for the same applications and also for inorganic materials synthesis. As a result, the exploitation of the peculiar properties of ILs for metal sulfide synthesis could provide attractive new avenues for the generation of new, highly specific metal sulfides for numerous applications. This article therefore describes current developments in metal sulfide nano-particle synthesis as exemplified by a number of highlight examples. Moreover, the article demonstrates how ILs have been used in metal sulfide synthesis and discusses the benefits of using ILs over more traditional approaches. Finally, the article demonstrates some technological challenges and how ILs could be used to further advance the production and specific property engineering of metal sulfide nanomaterials, again based on a number of selected examples.}, language = {en} } @misc{KarKoerzdoerfer2020, author = {Kar, Manaswita and K{\"o}rzd{\"o}rfer, Thomas}, title = {Computational high throughput screening of inorganic cation based halide perovskites for perovskite only tandem solar cells}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {5}, issn = {1866-8372}, doi = {10.25932/publishup-51683}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-516831}, pages = {11}, year = {2020}, abstract = {We search for homovalent alternatives for A, B, and X-ions in ABX(3) type inorganic halide perovskites suitable for tandem solar cell applications. We replace the conventional A-site organic cation CH3NH3, by 3 inorganic cations, Cs, K, and Rb, and the B site consists of metals; Cd, Hg, Ge, Pb, and Sn This work is built on our previous high throughput screening of hybrid perovskite materials (Kar et al 2018 J. Chem. Phys. 149, 214701). By performing a systematic screening study using Density Functional Theory (DFT) methods, we found 11 suitable candidates; 2 Cs-based, 3 K-based and 6 Rb-based that are suitable for tandem solar cell applications.}, language = {en} }