If an ion pair such as Li+NO−3 forms a solvate in a liquid solvent S of formula Snmax⋅Li+NO−3 it is possible to prepare each of the nmax-different solvates in low temperature matrices by using a range of solvent–argon matrix compositions. Each successive S molecule coordinated to the lithium reduces the cation distortion of the nitrate ion through a combination of cation charge neutralization and coordination-shell steric forces which act to increase the cation–anion bond length. As a result the splitting of the ν3(e) nitrate degeneracy (Δν3) of 262 cm−1 collapses in a surprisingly uniform stepwise manner as n increases for the matrix-isolated solvates. In this study Δν3 has been measured for the nmax different Li+NO−3 solvates for each of the solvents glyme, THF, DMF, and H2O which appear to display nmax values of 3, 4, 4, and 5, respectively (glyme is bidentate so nmax=3 but CNmax=6). Thus, part of the infrared spectrum of each solvate has been observed and assigned, the nmax solvation stages enumerated and the magnitude of the effect of each solvent molecule on the strength of the cation–anion interaction (δΔν3) noted. A comparison of the matrix data with liquid solution ν3(e) measurements indicates that, in general, CNmax (matrix)≳CNmax (solution) and that solution equilibria involving different solvates can be identified and characterized. The new H2O matrix data are remarkable both in the clarity with which the bands for five different hydrates were observed and in the very close correspondence of the observed δΔν3 values, for n=1, 2, and 3, with the values previously reported from an overlap-population analysis for the N–O bonds as deduced from an ab initio SCF calculation. The matrix data for the flexible ‘‘bidentate’’ ligand (glyme) show that there is at least a 50% chance of the ligand isomerizing to the bidentate cis structure during coordination, while the data for the liquid glyme solution suggest that two of the three ligands assume a bidentate form.