Neudecker, Tim
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Preferred name
Neudecker, Tim
Official Name
Neudecker, Tim
Alternative Name
Stauch, Tim (geb.)
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GND
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Item-typ:Veröffentlichung, Nitrile‐Substituted 2‐(Oxazolinyl)‐Phenols: Minimalistic Excited‐ State Intramolecular Proton Transfer (ESIPT)‐Based Fluorophores(Royal Society of Chemistry, 2020-05-04); ; ; Herein, we present minimalistic single-benzene, excited-state intramolecular proton transfer (ESIPT)-based fluorophores as powerful solid-state emitters. The very simple synthesis gave access to all four regioisomers of nitrile-substituted 2-(oxazolinyl)-phenols (MW = 216.1). In respect of their emission properties they can be divided into aggregation-induced emission enhancement (AIEE) luminophores (1-CN and 2-CN), dual state emission (DSE) emitters (3-CN) and aggregation-caused quenching (ACQ) fluorophores (4-CN). Remarkably, with compound 1-CN we discovered a minimalistic ESIPT-based fluorophore with extremely high quantum yield in the solid state ΦF = 87.3% at λem = 491 nm. Furthermore, quantum yields in solution were determined up to ΦF = 63.0%, combined with Stokes shifts up till 11.310 cm−1. Temperature dependent emission mapping, crystal structure analysis and time-dependent density functional theory (TDDFT) calculations gave deep insight into the origin of the emission properties.Wissenschaftlicher ArtikelBand:8Heft:2742 39 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Alliacane-Type Secondary Metabolites from Submerged Cultures of the Basidiomycete Clitocybe nebularis(American chemical society, 2022-09-21); ; ; ; Seven sesquiterpenoids, named nebucanes A–G (1–7), featuring a rare alliacane scaffold with unprecedented furan or pyrrole functions, were isolated from the fermentation broth of Clitocybe nebularis. Their structures were established on the basis of 1D/2D NMR spectroscopic analyses, HR-(+)-ESIMS spectra, and comparison of measured and calculated CD spectra for determination of the absolute configuration. Assessing the biological activities, nebucane D (4) exhibited antifungal effects against Rhodotorula glutinis, while nebucane G (7) displayed significant cytotoxicity against MCF-7 and A431 cell lines.Wissenschaftlicher ArtikelBand:85Heft:1063 113 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Modeling Molecules under Pressure with Gaussian Potentials(American chemical society, 2020-12-22); ; ; ; The computational modeling of molecules under high pressure is a growing research area that augments experimental high-pressure chemistry. Here, a new electronic structure method for modeling atoms and molecules under pressure, Gaussians On Surface Tesserae Simulate HYdrostatic Pressure (GOSTSHYP) approach, is introduced. In this method, a set of Gaussian potentials is distributed evenly on the van der Waals surface of the investigated chemical system, leading to a compression of the electron density and the atomic scaffold. Since no parameters other than pressure need to be specified, GOSTSHYP allows straightforward geometry optimizations and ab initio molecular dynamics simulations of chemical systems under pressure for nonexpert users. Calculated energies, bond lengths, and dipole moments under pressure fall within the range of established computational methods for high-pressure chemistry. A Diels–Alder reaction and the cyclotrimerization of acetylene showcase the ability of GOSTSHYP to model pressure-induced chemical reactions. The connection to mechanochemistry is pointed out.Wissenschaftlicher ArtikelBand:17Heft:135 49 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, A mechanochemical model for the simulation of molecules and molecular crystals under hydrostatic pressureA novel mechanochemical method for the simulation of molecules and molecular crystals under hydrostatic pressure, the eXtended Hydrostatic Compression Force Field (X-HCFF) approach, is introduced. In contrast to comparable methods, the desired pressure can be adjusted non-iteratively and molecules of general shape retain chemically reasonable geometries even at high pressure. The implementation of the X-HCFF approach is straightforward, and the computational cost is practically the same as for regular geometry optimization. Pressure can be applied by using any desired electronic structure method for which a nuclear gradient is available. The results of the X-HCFF for pressure-dependent intramolecular structural changes in the investigated molecules and molecular crystals as well as a simple pressure-induced dimerization reaction are chemically intuitive and fall within the range of other established computational methods. Experimental spectroscopic data of a molecular crystal under pressure are reproduced accurately.Wissenschaftlicher ArtikelBand:153Heft:1343 109 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Substitution Effect on 2-(Oxazolinyl)-phenols and 1,2,5-Chalcogenadiazole-Annulated Derivatives: Emission-Color-Tunable, Minimalistic Excited-State Intramolecular Proton Transfer (ESIPT)-Based Luminophores(American chemical society, 2021-09-28); ; ; ; Minimalistic 2-(oxazolinyl)-phenols substituted with different electron-donating and -withdrawing groups as well as 1,2,5-chalcogenadiazole-annulated derivatives thereof were synthesized and investigated in regard to their emission behavior in solution as well as in the solid state. Depending on the nature of the incorporated substituent and its position, emission efficiencies were increased or diminished, resulting in AIE or ACQ characteristics. Single-crystal analysis revealed J- and H-type packing motifs and a so-far undescribed isolation of ESIPT-based fluorophores in the keto form.Wissenschaftlicher ArtikelBand:86Heft:2146 48 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Twist and Return−Induced Ring Strain Triggers Quick Relaxation of a (Z)-Stabilized Cyclobisazobenzene(American chemical society, 2018-07-31); ; ; ; Continuous irradiation of the thermodynamically stable (Z,Z)-cyclobisazobenzene does not lead to accumulation of a (Z,E) or (E,E) isomer as one might expect. Our combined experimental and computational investigation reveals that Z → E photoisomerization still takes place on an ultrafast time scale but induces large ring strain in the macrocycle, which leads to a very fast thermal back-isomerization, preventing photostationary accumulation of (E)-isomers.Wissenschaftlicher ArtikelBand:9Heft:1657 41 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, A Two-Step Baromechanical Cycle for Repeated Activation and Deactivation of MechanophoresMechanophores that are embedded in a polymer backbone respond to the application of mechanical stretching forces by geometric changes such as bond rupture. Typically, these structural changes are irreversible, which limits the applicability of functional materials incorporating mechanophores. Using computational methods, we, here, present a general method of restoring a force-activated mechanophore to its deactivated form by using hydrostatic pressure. We use the spiropyran-merocyanine (SP-MC) interconversion to show that repeated activation of the SP mechanophore and deactivation of MC can be achieved by alternating mechanical stretching and hydrostatic compression, respectively. In the baromechanical cycle, MC acts as a “barophore” that responds to hydrostatic pressure by bond formation. The activation and deactivation of SP/MC are understood in terms of strain and electronic effects. Beneficially, this two-step baromechanical cycle can be observed in real time by using UV/vis spectroscopy. Our calculations pave the way for improving the applicability and reusability of force-responsive materials.Wissenschaftlicher ArtikelBand:12Heft:3941 54 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Mechanical Switching of Aromaticity and Homoaromaticity in Molecular Optical Force Sensors for PolymersThe sensing of mechanical stress in polymers is indispensable for investigating the origin and propagation of cracks that lead to material failure and for designing mechanically responsive polymers. Here the unique approaches of using the force-induced switching of aromaticity and homoaromaticity in molecular optical force sensors for the real-time measurement of mechanical forces acting in stretched polymers are suggested. The mechanical switching of aromaticity in Dewar benzene is an irreversible event, whereas the degree of π-orbital overlap in homoaromatic compounds like homotropylium can be adjusted progressively over a wide range of forces. Using computational methods, it is demonstrated that both approaches lead to significant changes in the visible part of the UV/Vis spectra of the force sensors upon application of weak forces (pN–nN). Polymers that incorporate such molecular force sensors therefore change their color well before material failure occurs.Wissenschaftlicher ArtikelBand:24Heft:2969 143