Neutral and positively charged calcium ammonia complexes are investigated by means of high-level quantum chemical calculations. We report optimal structures, binding energies, and vibrational spectra for Ca(NH 3 ) 1−8 0,+ . The bigger Ca(NH 3 ) 6−8 0,+ complexes can be classified as solvated electron precursors (SEPs) and are best described as a Ca(NH 3 ) 6−8 2+ core with two or one peripheral electrons. In their ground state, only ∼10% of the outer electron density is estimated to be within the calcium van der Waals radius. For these systems, we calculated several lowlying electronic states, where electrons populate diffuse outer orbitals. The Aufbau principle for the outer electrons is found to be identical to previously studied SEPs: 1s, 1p, 1d, 1f, 2s, and 2p. We show that going from Ca(NH 3 ) 5 , which has an incomplete first coordination shell and the two valence electrons that are mainly in the valence sphere of calcium, to Ca(NH 3 ) 6 , both the vibrational and electronic features change abruptly. Infrared, visible, and ultraviolet spectroscopy can be used to identify and characterize calcium SEPs.

Ground and excited electronic states of V(NH3)0,±6 complexes, investigated with ab initio electronic structure theory, consist of a V(NH3)62+ core with up to three electrons distributed over its periphery.

The neutral and charged yttrium metal–ammonia complexes, [Y(NH3)8]0,±, are investigated quantum mechanically. It is shown that all of them bear a [Y(NH3)8]3+ core with two, three or four peripheral electrons.

Simultaneous control of the kinetics and thermodynamics of two different types of covalent chemistry allows pathway selectivity in the formation of hydrogelating molecules from a complex reaction network. This can lead to a range of hydrogel materials with vastly different properties, starting from a set of simple starting compounds and reaction conditions. Chemical reaction between a trialdehyde and the tuberculosis drug isoniazid can form one, two, or three hydrazone connectivity products, meaning kinetic gelation pathways can be addressed. Simultaneously, thermodynamics control the formation of either a keto or an enol tautomer of the products, again resulting in vastly different materials. Overall, this shows that careful navigation of a reaction landscape using both kinetic and thermodynamic selectivity can be used to control material selection from a complex reaction network.

Peroxisome proliferator receptor gamma (PPARγ), a type II nuclear receptor, fundamental in the regulation of genes, glucose metabolism, and insulin sensitization has been shown to be impacted by per- and poly-fluoroalkyl substances (PFASs). To consider the influence of PFASs upon PPARγ, the molecular interactions of 27 PFASs have been investigated. Two binding sites have been identified on the PPARγ homodimer structure: the dimer pocket and the ligand binding pocket, the former has never been studied prior. Molecular dynamics calculations were performed to gain insights about PFASs-PPARγ binding and the role of acidic and basic residues. The electrostatic interactions for acidic and basic residues far from the binding site were probed, together with their effect on PPARγ recognition. Short-range electrostatic and van der Waals interactions with nearby residues and their influence on binding energies were investigated. As the negative effects of perfluorooctane sulfonate acid were previously shown to be alleviated by one of its natural ligands, l -carnitine, here, the utility of l -carnitine as a possible inhibitor for other PFASs has been considered. A comparison of the binding patterns of l -carnitine and PFASs provides insights toward mitigation strategies for PFASs.

a b s t r a c tThe lowest excited electronic states of the permanganate ion MnO 4 À are calculated using a hierarchy of coupled cluster response approaches, as well as time-dependent density functional theory. It is shown that while full linear response coupled cluster with singles and doubles (or higher) performs well, that permanganate represents a stern test for approximate coupled cluster response models, and that problems can be traced to very large orbital relaxation effects. TD-DFT is reasonably robust although errors around 0.6 eV are still observed. In order to further investigate the strong correlations prevalent in the electronic ground state large-scale RASSCF calculations were also performed. Again very large orbital relaxation in the correlated wavefunction is observed. Although the system can qualitatively be described by a single configuration, multi-reference diagnostic values show that care must be taken in this and similar metal complexes.

Multi-reference configuration interaction and coupled cluster calculations were carried out for the ground and several low-lying excited electronic states for PdO, PdO+, and PdO-. Spin-orbit coupling, core-correlation effects, and large correlation-consistent basis sets were employed. We report bond lengths, spectroscopic constants, energetics, and potential energy curves for all of the considered states. Our calculations settle the assignment for the previously recorded peaks of the experimental PdO- photoelectron spectrum. We found that the spin-orbit effects mix considerably the Λ-S states of PdO, changing dramatically the order of its low-lying electronic states. The ground states of these species were found to be 4Σ- for PdO+, 3Σ- for PdO, and 2Π for PdO-. Going from PdO to PdO+, the electron detaches from a σ orbital which is localized on the metal. Going from PdO to PdO-, the additional electron attaches a π orbital, which is more localized on oxygen. For PdO- we found six electronic states bound with respect to PdO.

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