Alberto Fernández‐Alarcón

7‐Azaindole has been integrated as building block with complementary N−H⋅⋅⋅N hydrogen bonding sites for the synthesis of a tetrahedral molecular tecton, namely tetra(α‐carbolin‐6‐yl)methane, TACM. The self‐assembly of this molecule results in a 3D hydrogen‐bonded organic framework (HOF). This supramolecular structure constitutes a crystalline microporous material with an extraordinary thermal and chemical robustness. Single crystal X‐ray diffraction reveals how the five‐fold catenation of diamonoid systems, stabilized by hydrogen bonds and π–π interactions, form an interpenetrated network with monodimensional channels. The structural features of the crystalline material are also observed by transmission electron microscopy (TEM). Additionally, the microporosity of the activated TACM‐HOF is characterized by gas sorption (N₂, CO₂, CH₄ and H₂) experiments performed at different pressures. A selective adsorption is observed for CO₂ uptake and TACM‐HOF also presents a good adsorption capacity for H₂ among supramolecular organic frameworks.

7‐Azaindole has been integrated as building block with complementary N−H⋅⋅⋅N hydrogen bonding sites for the synthesis of a tetrahedral molecular tecton, namely tetra(α‐carbolin‐6‐yl)methane, TACM. The self‐assembly of this molecule results in a 3D hydrogen‐bonded organic framework (HOF). This supramolecular structure constitutes a crystalline microporous material with an extraordinary thermal and chemical robustness. Single crystal X‐ray diffraction reveals how the five‐fold catenation of diamonoid systems, stabilized by hydrogen bonds and π–π interactions, form an interpenetrated network with monodimensional channels. The structural features of the crystalline material are also observed by transmission electron microscopy (TEM). Additionally, the microporosity of the activated TACM‐HOF is characterized by gas sorption (N₂, CO₂, CH₄ and H₂) experiments performed at different pressures. A selective adsorption is observed for CO₂ uptake and TACM‐HOF also presents a good adsorption capacity for H₂ among supramolecular organic frameworks.

An exponential effort in the design of the hole-transporting materials (HTMs) during the last decade is motivated by their key role as p-type semiconductors for (opto)electronics. Although structure-property relationships have been successfully rationalized to decipher optimal site substitutions, aliphatic chains length or efficient aromatic cores for enhanced charge conduction, the impact of molecular shape, material morphology and dynamic disorder is generally overlooked. In this work, we characterize by means of a multi-level theoretical approach the charge transport properties of a novel planar small-molecule HTM based on the indoloindole aromatic core (IDIDF), and compare it with spherical-like spiro-OMeTAD. Hybrid DFT calculations predict moderate band dispersions in IDIDF associated to the main transport direction characterized by π-π stacked molecules, both between the indoloindole cores and the thiophene groups. Strongly coupled dimers show relevant non-covalent interactions, indicating that NCI surfaces are a necessary but not exclusive requirement for large electronic couplings. We evidence remarkable differences in the site energy standard deviation and electronic coupling distributions between the conduction paths of IDIDF and spiro-OMeTAD. Despite the spherical vs planar shape, however, theoretical calculations predict in the static crystal strong direction-dependent charge transport in the two HTMs, with ca. one-order-of-magnitude higher mobility (μ) for IDIDF. The dynamical disorder promoted by finite temperature effects in the crystal leads to a reduction of the hole transport properties in both HTMs, with maximum values of 2.42 and 4.2 × 10⁻² cm² V⁻¹ s⁻¹ for IDIDF and spiro-OMeTAD, respectively, as well as a significant increase in the transport anisotropy in the latter. Finally, the impact of the material amorphousness in the hole mobility is analysed by modelling a fully random distribution of HTM molecules. An average (lower-bound) mobility of 1.1 × 10⁻³ and 4.9 × 10⁻⁵ cm² V⁻¹ s⁻¹ is predicted for planar IDIDF and spherical spiro-OMeTAD, respectively, in good accord with the experimental data registered in thin-film devices. Our results demonstrate the strong influence of molecular shape, dynamic structural fluctuations, and crystal morphology on the charge transport, and pose indoloindole-based HTMs as promising materials for organic electronics and photovoltaics.

The front cover artwork is provided by Dr. Alberto Fernández‐Alarcón. The image symbolizes the interactions of a molecule, via its orbitals, with an electromagnetic field, to produce the spectroscopic signals observed in NMR. Read the full text of the Concept at 10.1002/cphc.202200667.

The implementation of fast relativistic methods based on density functional theory, in conjunction with localized molecular orbital (LMO) based analysis, allows straightforward interpretations of NMR parameters in terms of contributions from core shells, lone pairs, and bonds, for compounds containing elements from across the periodic table. We present a conceptual review of a frequently used LMO analysis of NMR parameters calculated in the presence of spin‐orbit interactions and other relativistic effects. An accompanying example focuses on the ¹⁵N shielding in a heavy metal complex.

Silver(I) coordination compounds display an interesting geometrical diversity, the possibility of having distinct coordination numbers (typically from 2 to 4) and the capability of forming argentophilic (Ag⋅⋅⋅Ag) interactions. These properties complicate the accurate prediction of structures of silver complexes under certain experimental conditions. In this work, we show how subtle modifications in thiolate and phosphine ligands exert important effects on the nuclearity and geometry of phosphine caped clusters [Ag(SR)]_n(n=4, 6 and 8). We rationalize these effects in terms of the electronic environment of silver centers by analyzing the electronic density of the single‐crystal X‐ray structures via the Quantum Theory of Atoms in Molecules (QTAIM) and the Non‐Covalent Interaction (NCI)‐Index. Furthermore, we characterized attractive and repulsive argentophilic contacts by means of the Interacting Quantum Atoms (IQA) energy partition. Our results provide insights on the effects of ancillary ligands in controlling the structure of silver‐thiolate clusters. Such control is relevant towards a bottom‐up approach to the atomic precise construction of higher nuclearity clusters.