Stability and structure of benzene dimer cation (C6H6)+2 in the gas phase

摘要: The gas‐phase equilibria of the clustering reaction (C6H6)+n−1+C6H6 =(C6H6)+n were studied with a pulsed electron‐beam high‐pressure mass spectrometer. enthalpy changes −ΔH0n−1,n for n=2–4 determined to be 20.6±1.0, 7.8±0.5, and ∼7 kcal/mol, respectively. structure dimer cation (C6H6)+2 was by ab initio spin‐restricted open‐shell Hartree–Fock molecular orbital (ROHF MO) calculations. Two isomers, ‘‘axial C2 ’’ ‘‘parallel C2v, are calculated located at potential‐energy minima. axial is 3.0 kcal/mol more stable than parallel C2v ROHF/6‐31G**//ROHF/3‐21G.