Fig. 4. (a) IRMPD spectrum of the mass-selected [(2-PhPy)₂Pd(OAc)]⁺ complex and theoretical IR spectra of (b) ^Pd1_a, (c) ^Pd2_a and (d) ^Pd3_a. The line spectra are presented along with a Gaussian function with fwhm = 16 cm^–1. Corresponding calculated structures can be seen in Fig. S12 of the ESI.† .