Observation of Simultaneous v_(1)(SF_(6)) + v_(3)(NF_(3)) and v_(2)(SF_(6)) + v_(3)(NF_(3)) Transitions Enhanced by the Resonance Dipole-Dipole Interaction with the v_(1) + v_(3) and v_(2) + v_(3) States of the SF_(6) Molecule

摘要

IR spectra of the solution of SF_(6) molecules in liquid NF_(3) at 84 K have been recorded. In a solvent transmission window of 1500-1750 cm~(-1), two wide absorption bands with pronounced peaks in the high-frequency part are observed. The profile of these bands is explained by the influence of the resonance dipole-dipole (RDD) interaction of the states of the simultaneous transition v_(1)(SF_(6)) + v_(3)(NF_(3)) and v_(2)(SF_(6)) + v_(3)(NF_(3)) with the states (v_(1) + v_(3)) and (v_(2) + v_(3)) of the SF_(6) molecules, respectively. The use of three isotopic modifications ~(32)SF_(6), ~(33)SF_(6), and ~(34)SF_(6) has allowed us to vary the resonance detuning and thus to change the strength of the RDD interaction. With the liquid near the melting point being represented as a close-packed cubic crystal, the profile was calculated and its spectral characteristics were determined. The frequencies of the main peaks coincide with the experimental values accurate to the error.