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A route towards covalent functionalization of chemically inert 2H-MoS2 exploiting sulfur vacancies is explored by means of (TD)DFT and GW/BSE calculations. Functionalization via nitrogen incorporation at sulfur vacancies is shown to result in more stable covalent binding than via thiol incorporation. In this way, defective monolayer MoS2 is repaired and the quasiparticle band structure as well as the remarkable optical properties of pristine MoS2 are restored. Hence, defect-free functionalization with various molecules is possible. Our results for covalently attached azobenzene, as a prominent photo-switch, pave the way to create photoresponsive two-dimensional (2D) materials.

Rolf Trauzettels Vorlesungen und Seminare zur Geschichte, Philosophie, Sprache und Literatur des vormodernen China, das in seinem mentalitatsgeschichtlich gepragten Verstandnis auch nach dem Unterg...

Solid-state excitonic excitations play an increasingly important role in optoelectronic and light harvesting processes due to their ubiquitous presence in dipolar two-dimensional materials. Here we...

A computational approach is presented which allows the calculation of free energies profiles for exciton transfer processes within the framework of ab initio molecular dynamics (AIMD) simulations, sampling both the electronic and the nuclear degrees of freedom. To achieve this, restraining potentials are imposed on the centres of maximally localized Wannier orbitals. The resulting quantum-mechanical orbital forces are derived analytically and implemented in an AIMD program. In analogy to classical umbrella sampling techniques, these restraints are used to control an exciton transfer by incrementally moving the Wannier centres corresponding to the electron-hole pair along a suitable reaction coordinate. The new method is applied to study exciton transfer between two stacked penta(3-methylthiophene) molecules as a function of intermolecular distance. From the resulting free energy profiles, exciton transfer rates and diffusion constants are estimated, which prove to be in line with experimental results.

A route towards covalent functionalization of chemically inert 2H-MoS

Solid-state excitonic excitations play an increasingly important role in optoelectronic and light harvesting processes due to their ubiquitous presence in dipolar two-dimensional materials. Here we show that long-lived solid-state excitons induce chemical reactions in adsorbed molecules and thus convert light into chemical energy. For the model system (NO)

A molecular rotor based on N-heterocyclic carbenes (NHCs) has been rationally designed following theoretical predictions, experimentally realized, and characterized. Utilizing the structural tunability of NHCs, a computational screening protocol was first applied to identify NHCs with asymmetric rotational potentials on a surface as a prerequisite for unidirectional molecular rotors. Suitable candidates were then synthesized and studied using scanning tunneling microscopy/spectroscopy (STM/STS), analytical theoretical models, and molecular dynamics simulations. For our best NHC rotor featuring a mesityl N substituent on one side and a chiral naphthylethyl substituent on the other, unidirectional rotation is driven by inelastic tunneling of electrons from the NHC to the STM tip. While electrons preferentially tunnel through the mesityl N substituent, the chiral naphthylethyl substituent controls the directionality. Such NHC-based surface rotors open up new possibilities for the design and construction of functionalized molecular systems with high catalytic applicability and superior stability compared with other classes of molecular rotors.

Chemical treatments to enhance photoluminescence (PL) in MoS2 have been explored extensively by experimental means in recent years. However, satisfactory theoretical explanations of the underlying mechanisms remain elusive. In this work, the surface reactions of the superacid bis(trifluoromethane)-sulfonimide (TFSI), hydrogen peroxide (H2O2), molecular oxygen (O2), and sulfuric acid (H2SO4) on a defective MoS2 monolayer have been studied using first principles calculations. An oxygen transfer reaction into a sulfur vacancy with a low activation barrier and thus significant reaction rates already at room temperature has been found. Band structure unfolding techniques show that the incorporation of oxygen atoms into sulfur vacancies restores the band structure of pristine MoS2, which is predicted to have a high PL quantum yield. PL spectroscopy is used to examine the effect of chemical treatment on PL intensity. Our experimental findings support our theoretical predictions, as PL in MoS2 is enhanced by up to a factor 20 after treatment with H2O2 or H2SO4, while the spectral shape is only slightly altered.

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. Ab initio calculations provide further 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 heterogeneous active species.

Chemical treatments to enhance photoluminescence (PL) in MoS2 have been explored extensively by experimental means in recent years. However, satisfactory theoretical explanations of the underlying mechanisms remain elusive. In this work, the surface reactions of the superacid bis(trifluoromethane)-sulfonimide (TFSI), hydrogen peroxide (H2O2), molecular oxygen (O2), and sulfuric acid (H2SO4) on a defective MoS2 monolayer have been studied using first principles calculations. An oxygen transfer reaction into a sulfur vacancy with a low activation barrier and thus significant reaction rates already at room temperature has been found. Band structure unfolding techniques show that the incorporation of oxygen atoms into sulfur vacancies restores the band structure of pristine MoS2, which is predicted to have a high PL quantum yield. PL spectroscopy is used to examine the effect of chemical treatment on PL intensity. Our experimental findings support our theoretical predictions, as PL in MoS2 is enhanced by up to a factor 20 after treatment with H2O2 or H2SO4, while the spectral shape is only slightly altered.

The present paper analyzes the rhetorical functions of verbal parallels in selected pre-imperial Qín 秦 (prior to 221 B.C.E.) and early imperial Qín (221–206 B.C.E.) and Western Hàn 漢 (206/202 B.C.E.–9 C.E.) memorials. Following the lead of Richard L. Schultz (The Search for Quotation: Verbal Parallels in the Prophets, 1999), it furnishes evidence that the authors of these petitions and remonstrances, which normally had to be submitted to the throne in writing before they could be orally presented to kings or emperors, employed quotations not only to embellish their statements or to give authority to them but also utilized them as argumentative figures of thought. In the samples under review, citations serve as elementary links in the argumentative chain of the quoting texts and even add a second layer of meaning to them, thus providing access to their argumentative “deep structure”. Moreover, when employed as structural devices, verbal parallels organize the memorials by introducing new argumentative steps not only from the point of view of contents but also formally through being topicalized and embedded into causal clauses and therefore can serve as criteria for dividing these texts into sense-units.

We combined an asymmetric cyclometalated C^N^N Pt(II) complex with three different classes of monodentate ancillary ligands, namely a bulky phosphine, a tilted pyridine, and either a tilted or a coplanar isocyanide. The controlled planarization of the coordination environment yields green, orange or red phosphors. Electronic structure calculations using DFT reveal the excimeric intermolecular interactions in the excited triplet state, resulting in tunable photophysical properties. Finally, we assess the suitability of the ancillary ligands for optoelectronic applications by investigating the molecular integrity upon sublimation with the aid of scanning tunneling microscopy (STM). The ancillary ligand controls the surface-induced chiral self-assembly of the molecules on metallic substrates, as well as the availability of loose coordination sites. The concordance between the photoluminescence spectra and electroluminescence profiles for solution-processed and vapour-deposited devices confirm the predictions attained by STM regarding molecular integrity and processability.

Preface Introduction Raji C. Steineck and Christian Schwermann Composite Authorship in Western Zhou Bronze Inscriptions: The Case of the "Tianwang gui" Inscription Christian Schwermann Authorship in the Canon of Songs (Shi Jing) Alexander Beecroft The Compiler as the Narrator: Awareness of Authorship, Authorial Presence and Author Figurations in Japanese Imperial Anthologies, with a Special Focus on the Kokin wakashu Simone Muller Fluidity of Belonging and Creative Appropriation: Authorship and Translation in an Early Sinic Song ("Kongmudoha Ka") Marion Eggert Appropriating Genius: Jin Shengtan's Construction of Textual Authority and Authorship in his Commented Edition of Shuihu Zhuan (The Water Margin Saga) Roland Altenburger Enlightened Authorship: The Case of Dogen Kigen Raji C. Steineck Index

There are two accounts of authorship in early China, a 'traditional' one and a 'modern' one. The traditional view implies that from the very beginning Chinese writers have both a strong awareness that texts can be created by a single person and a clear commitment to the concept of individual authorship. The inscription on the "Tiānwang guǐ", i.e. the "guǐ-Tureen of Tiānwang", belongs to the earliest Western Zhōu bronze epigraphs. It can be dated to the reign of King Wǔ (Wǔ wang, r. 1049/45-1043 B.C.E.) and have been produced shortly after the Muyě in 1045 B.C.E., when the Zhōu conquered the preceding Shāng dynasty. The inscription commemorates the accomplishments of one of its authors after King Wǔ's conquest of the Shāng. The inscription poses a philological problem that is particularly relevant to our interpretation and understanding of the text. Keywords: authorship; earliest Western Zhōu bronze epigraphs; early China; guǐ-Tureen of Tiānwang; reign of King Wǔ; Shāng dynasty; Tiānwang guǐ