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Twin jet deposition has been employed with conventional matrix isolation for the study of isolated complexes of crown ethers with small neutral guests. For each system, from 1,4 dioxane to 18-crown-6, a single 1:1 complex was isolated. The dominant spectral feature of the complex was the stretching mode of the diatomic acid, shifted to lower energies from the parent position. For example, the complex of HF with 18-crown-6 absorbs at $3290cm-1$, while the complex of CIF with 18-crown-6 absorbs at about $665cm-1$. In addition, considerable broadening of the absorption was noted, compared to complexes of these acids with single-oxygen donors. The shifts observed here are quite similar to those observed for single 0-atom donors, suggesting that the cooperativity observed for crown ether complexes of metal cations is not important for the current complexes.