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Highlights: [•] We study the potential energy surface of the acetone–carbon dioxide complex with ab initio methods. [•] We analyze the contributions to the interaction energy with variational and perturbative approaches. [•] We describe non-conventional structures in which dispersion energy plays a key role. [•] We show that current density functional theory methods are unsuitable to describe this type of complexes. [ABSTRACT FROM AUTHOR]

Perylenediimides (PDIs) are the focus of a huge number of research lines for their awesome properties which can be modulated over a wide range by chemical modification of their structure. However, industrial applications require reduced costs in materials preparation and transformation. In this contribution we explore the ability of sulfur-substituted PDIs to vary their electronic character from strong electron-donating to strong electron-accepting in just one reaction. [Display omitted] • Change in the UV–vis absorption depending on the oxidation state of the sulfur substituent. • Modulation of the fluorescence quantum yield with the oxidation state of the sulfur substituents. • Tunability of the electronic character of the perylenediimides as a function of the oxidation state of the sulfur atom. [ABSTRACT FROM AUTHOR]

• Efficient methodology for post-synthetic functionalization of polyaniline with phosphorus-containing compounds. • The electroactivity of modified polyaniline depends on the phosphorus precursor. • DFT results proved that the reaction occurs through the imine groups and the phosphorus atoms. P-postmodified polyaniline was obtained by reacting phosphorus trichloride (PCl 3) and chlorodiphenylphosphine (PPh 2 Cl) and polyaniline (PANI), under mild conditions. The reaction was found to be very selective, as only the imine groups were involved in the P-functionalization, and efficient as well, affording a P-loading of 3 at.% and 5 at.% for PPh 2 Cl and PCl 3 , respectively. All the polymers were characterized by different techniques and the results were endorsed by theoretical calculations. Experimental and Density Functional Theory results proved that the reaction occurs through the imine groups and the phosphorus atoms, generating N P bonds. The electrochemical properties of the N P modified materials were evaluated and the catalytic activity towards oxygen reduction reaction was measured. It was found that a high concentration of phenyl groups from PPh 2 Cl (about 3 at.%) affected negatively the activity of the catalyst since they prevented the access of the oxygen molecules to the catalytic active sites. However, a lower amount of PPh 2 groups (1 at.%) or the use of PCl 3 avoided this hindrance and resulted in an improved catalytic activity with respect to pristine PANI. [ABSTRACT FROM AUTHOR]