Experimental interrogation of the multidimensional He+ICl(E,v†) and He+ICl(β,v†) intermolecular potential energy surfaces

Resonant two-photon excitation of the T-shaped and linear He⋯IC35l(X,v″=0) complexes is used to access the intermolecular vibrational levels bound within the He+ICl(β,v†=0–2) and He+ICl(E,v†=11,12) intermolecular potentials. The excitation utilizes different metastable intermolecular vibrational levels within the He+ICl(A,v′=15) and He+ICl(B,v′=2,3) potentials to access levels with varying intermolecular vibrational excitation in the ion-pair states. In addition to providing data revealing properties of the He+ICl(E,v†) and He+ICl(β,v†) potentials, the transition energies of the observed features permit the relative binding energies of the T-shaped and linear ground-state He⋯ICl(X,v″=0) conformers to be accurately measured. The binding energies of the T-shaped and linear He⋯IC35l(X,v″=0) conformers are 16.6(3) and 22.0(2) cm−1, respectively. These values and the observed transition energies are then used to set the binding energies of the T-shaped He⋯IC35l complexes in the He+ICl(A,v′=15), He+ICl(B,v′=3),...