Influence of Ligand Complexity on the Spectroscopic Properties of Type 1 Copper Sites: A Theoretical Study.

Multi-copper oxidases (MCOs) are enzymes of significant interest in biotechnology due to their efficient catalysis of oxygen reduction to water, making them valuable in sustainable energy production and bio-electrochemical applications. This study employs time-dependent density functional theory (TDDFT) to investigate the electronic structure and spectroscopic properties of the Type 1 (T1) copper site in Azurin, which serves as a model for similar sites in MCOs. Four model complexes of varying complexity were derived from the T1 site, including 3 three-coordinate models and 1 four-coordinate model with axial methionine ligation, to explore the impact of molecular branches and axial coordination.

Modeling adsorption reactions of ammonium perchlorate on rutile and anatase surfaces.

In this work, the effects of two TiO polymorphs on the decomposition of ammonium perchlorate (NHClO) were studied experimentally and theoretically. The interactions between AP and various surfaces of TiO were modeled using density functional theory (DFT) calculations. Specifically, the adsorption of AP on three rutile surfaces (1 1 0), (1 0 0), and (0 0 1), as well as two anatase surfaces (1 0 1), and (0 0 1) were modeled using cluster models, along with the decomposition of adsorbed AP into small molecules.

The effect of water on gold supported chiral graphene nanoribbons: rupture of conjugation by an alternating hydrogenation pattern.

In the last few years we have observed a breakpoint in the development of graphene-derived technologies, such as liquid phase filtering and their application to electronics. In most of these cases, they imply exposure of the material to solvents and ambient moisture, either in the fabrication of the material or the final device. The present study demonstrates the sensitivity of graphene nanoribbon (GNR) zigzag edges to water, even in extremely low concentrations.

Polyradical character assessment using multireference calculations and comparison with density-functional derived fractional occupation number weighted density analysis.

The biradicaloid character of different types of polycyclic aromatic hydrocarbons (PAHs) based on small band gaps is an important descriptor to assess their opto-electronic properties. In this work, the unpaired electron densities and numbers of unpaired electrons ( values) calculated at the high-level multireference averaged quadratic coupled-cluster (MR-AQCC) method are used to develop a test set to assess the capabilities of different biradical descriptors based on density functional theory. A benchmark collection of 29 different compounds has been selected.

High-Level Multireference Investigations on the Electronic States in Single-Vacancy (SV) Graphene Defects Using a Pyrene-SV Model.

The nonplanar character of graphene with a single carbon vacancy (SV) defect is investigated utilizing a pyrene-SV model system by way of complete-active-space self-consistent field theory (CASSCF) and multireference configuration interaction singles and doubles (MR-CISD) calculations. Planar structures were optimized with both methods, showing the B state to be the ground state with three energetically close states within an energy range of 1 eV. These planar structures constitute saddle points.