Density Functional Theory Modeling of Solid-State Nuclear Magnetic Resonances for Polycyclic Aromatic Hydrocarbons

Experimental solid-state nuclear magnetic resonance (SS-NMR) has been used to analyze different theoretical models for polycyclic aromatic hydrocarbon crystals of similar structure (naphthalene, anthracene, phenanthrene, picene, and triphenylene). We compare the accuracy of four modeling approaches to compute SS-NMR chemical shifts using ab initio density functional theory (DFT). Models based on X-ray cell parameters, on optimization of the cell with the Perdew, Burke, and Ernzerhof (PBE) approximation, and on two methods adding dispersion forces were compared (using Pearson's and mean absolute deviation correlation factors). Even though the intermolecular distances and cell volumes are different depending on the model, there is an overall good agreement between theoretical and experimental C-13 chemical shifts for all of them. An analysis of intermolecular distances and deviation from planarity in different models and their influence on theoretical chemical shieldings is also performed.