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The selective multiphoton excitation of vibrotational states of 32SF6 species has been done by a pulsed CO2 laser tuned at 948 cm-1. The Littrow grating arrangement with 100 lines/mm, 22° blazing angle is used to assure the laser bandwidth to be adequately less than the SF6 isotope shifts (17 cm-1). The subsequent molecular dissociation occurs at high power densities. A FTIR spectrometer with 4 cm-1 resolution is employed to register characteristic peaks of 32SF6 and 34SF6 at 948 and 931 cm-1 respectively. The dissociation rate strongly decreases at higher pressures due to rapid deactivation of excited molecules based on momentum transfer of vibrational-translational process by collisional events between 32SF6 and buffer molecules. Moreover the selectivity decreases at higher pressures, which mainly arises from vibrational-vibrational excitations of pertinent collisions among species to cause resonant obliteration of 34SF6 molecules, consequently.