Fabian Dietrich

MXenes are a versatile family of two-dimensional materials whose magnetic properties can be tailored through transition-metal substitution, opening promising opportunities for spintronic and magnetic sensing applications. In this work, we investigate the effect of vanadium doping on the magnetic properties of Ti 2 C MXenes by combining first-principles calculations and Monte Carlo simulations. Our results show that pristine Ti 2 C exhibits ferromagnetic (FM) intralayer and antiferromagnetic (AFM) interlayer exchange interactions, leading to a compensated AFM ground state. The incorporation of vanadium locally modifies the exchange pathways by introducing FM Ti–V and V–V couplings, while preserving the global AFM ordering. Although single V substitution induces only moderate changes in the magnetic response, double-doped configurations exhibit a significantly enhanced field-induced magnetization and magnetic susceptibility, evidencing a cooperative effect between multiple V centers. Among the studied configurations, the o -Ti 6 V 2 C 4 arrangement shows the strongest magnetic response, highlighting the importance of the relative dopant distribution in controlling the exchange topology. The enhanced low-field susceptibility persists up to room temperature, demonstrating the robustness of the V-induced magnetic perturbations against thermal fluctuations. These findings reveal that both dopant concentration and geometric distribution provide effective tuning parameters for engineering the magnetic functionality of MXenes, establishing multi-metallic Ti 2 C-based systems as promising candidates for future spintronic devices.

Functional groups and the electronic state determine the preferred binding site of methanol to the carbonyl group of chromone derivatives.

Photo‐switchable coatings for lithium ion batteries (LIB) can offer the possibility to control the diffusion processes from the electrode materials to the electrolyte and thus, for example, reducing the energy loss in the fully charged state. Fulgide derivatives, as known photo‐switches, are investigated concerning their use as coating for vanadium pentoxide, a potential cathode material for LIB. With the help of Density Functional Theory calculations, two fulgide derivatives are characterized with respect to their photophysics, their aggregation behaviour on the cathode material and the ability to form self‐assembled monolayers (SAM). Furthermore, the two states of the photo‐switchable coating are tested with respect to lithium diffusion from the cathode material, passing the SAM and entering the electrolyte. We found a difference for the energy barriers depending on the state of the photo‐switch, preferring its closed form. This behaviour can be used to prevent the loss of charge in batteries of portable devices.

Small anionic nickel clusters with ethanol are investigated with a combination of mass-selective infrared photodissociation spectroscopy in a molecular beam and density functional theory simulations at the BLYP/6-311g(d,p) and TPSSh/def2-TZVPP level. In this context, the O–H stretching vibration of the ethanol is analyzed to obtain information about the structural motif, the geometry of the metal core, and the spin state of the clusters. For the [Ni2(EtOH)]− and [Ni3(EtOH)]− clusters, we assign quartet states of motifs with a hydrogen bond from the ethanol to the linear nickel core. The aggregation of a further ethanol molecule, yielding the [Ni3(EtOH)2]− cluster, results in the formation of a cooperative hydrogen bond network between the nickel core and the two ethanol molecules.

Small cationic cobalt, and cobalt–nickel alloy clusters with ethanol attached are generated in a pulsed molecular beam experiment using a laser ablation source. While the metal center is successively varied with respect to size and composition, a full-size study of these transition metal clusters is possible. The clusters are investigated via IR photodissociation spectroscopy in the region of OH- and CH-stretching vibrations. The results are compared with theoretical data obtained from DFT calculations. Both frequency shifts and structural changes according to cluster size and composition are identified and discussed in detail, also with respect to cooperative effects. Trimeric metal clusters with an uneven number of nickel atoms show evidence for C–O cleavage of the ethanol molecule. This result is elucidated by further calculations concerning the reactivity, charge and energetic distributions.

A joint community effort to critically evaluate quantum chemical approaches to the prediction of vibrational shifts of hydrates in the gas phase.