Infrared absorption spectra of the Li2F2 rhombic dimer isolated in Xe, Ar, and Ar-mixed matrices suggest that rotational stereodynamics occurs for Li2F2 in its Xe trapping site. Providing evidence for this, the absorbance peak for the B-3u fundamental at 617 cm(-1) changes little upon annealing and heating processes, which cause the B-2u peak at 534 cm(-1) to lose most of its absorbance strength-despite their common provenience. The explanation is rooted in (a) the volume compatibility of Li2F2 and the Xe vacancy, (b) the D-2h symmetry of Li2F2, (c) the state-specific generation of rotational stereodynamics by vibrational relaxation of the 534 cm(-1) B-2u mode, and (d) the IR transparency manifested by Li2F2 isolated in Xe crystallites providing rough alignments between the B-2u transition dipole and the spectrometer IR beam. Analogous behavior appears to occur for the Xe-isolated LiF monomer.