Metal–Ligand Bonding Situation in Ruthenophanes Containing Multibridged Cyclophanes

Cation−π interactions in a set of ruthenophanes [Ru­(η6-CnHn)­(NH3)3]2+ (n = 16, 18, 20, 22, and 24) (1–9), containing multibridged cyclophanes as ligands, including [2.2]­paracyclophane and its multibridged analogs, [2n]­cyclophanes, are analyzed in terms of SAPT0/TZP and Su–Li EDA analyses. The calculations reveal that the coordination with cation [Ru­(NH3)3]2+ affects the structures of [2n]­ciclophane ligands, mainly the planarity of the coordinating ring. The EDA results show that the gradual addition of ethano bridges in [2n]­cyclophanes tends to strengthen the cation−π interaction between [Ru­(NH3)3]2+ and [2n]­cyclophane. Both Su–Li EDA and SAPT0 are in line, suggesting that the cation−π interactions present a predominant covalent character in complexes 1–9.