“…Fourth, only organic compounds have been explored, because the binding ability of the aromatic rings belonging to organometallic complexes can be influenced by the metal. In Figure 5, we show two examples (CSD codes FEPBOS 30 and MAFQIU 31 ) where the combination of both interactions determines the crystal packing. It is worth mentioning that a similar search performed for pyrrole, which has unfavorable hydrogen-bond/π-π synergy, has not revealed any hit.…”