We have used state-of-the-art ab initio RASPT2 computations using a 16 orbitals, 18 electrons active space to produce an extended three dimensional map of the potential energy surfaces (PESs) of the ground and first nπ * excited state of azobenzene along CNNC torsion and the two CNN bending angles, which are the most relevant coordinates for the trans-cis photoisomerization process. Through comparison with fully unconstrained optimizations performed at the same level of theory, we show that the three selected coordinates suffice to correctly describe the photoisomerization mechanism and the S 1-S 0 crossing seam. We also provide a map of the non-adiabatic coupling between the two states in the region where they get closer in energy. Eventually, we show that treating the two CNN bending angles as independent coordinates is fundamental to break the symmetry and couple the two electronic states. The accuracy of the S 0 and S 1 PESs and couplings was validated with semiclassical dynamics simulations in the reduced space of the scanned coordinates, showing results in good agreement with published full-coordinates dynamics.

The desymmetrization of N-(2-tert-butylphenyl)maleimides was realized by means of a Michael reaction of N-(tert-butoxycarbonyl)-3-phenyloxindoles leading to the corresponding axially chiral succinimides in high yields. The use of a squaramide cinchonidine organocatalyst was fundamental to achieve the simultaneous remote control of the stereogenic axis and adjacent quaternary and tertiary stereocenters.

The understanding of crystal formation in thin films and the precise knowledge of the relation between structure and surface diffusion are two important requirements for the efficient (nano)fabrication of organic electronic devices. Here a computational approach for simulating vapor-phase deposition is employed to obtain and investigate three types of crystalline thin films on graphite. All systems, namely pentacene, perfluoropentacene, and their 1:1 blend, which forms an alternate cocrystal, are constituted by recumbent molecules in accordance with experimental findings. The contributions of intermolecular interactions and of molecular rearrangements occurring during the deposition are analyzed to rationalize the final morphologies. Then, the generated structures are employed to evaluate the energy barriers that prevent molecular diffusion at terraces and step-edges, and to study the reorganization of the films upon high-temperature annealing. The broad agreement with experimental observations and the possibility of evaluating the potential energy surface at the molecular detail render the proposed approach a promising tool to make predictions for other systems.

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