We report the infrared spectra of Li+(CH4)(n), n = 1-9, clusters in the C-H stretching region using vibrational predissociation spectroscopy. Vibrational frequencies and geometries were calculated at the B3LYP/6-31+G* level with zero-point corrected binding energies at the MP2/6-31+G* level. Experiments and calculations indicated a first solvent shell size of four CH4. Second solvent shell ligands were identified by smaller frequency shifts and changes in relative intensity, suggesting a reduced influence of Li+ beyond the first shell. Perturbation of the CH4 vibrational modes appears to be dominated by the Li+center dot center dot center dot CH4 electrostatic interaction, while CH4 center dot center dot center dot CH4 interactions between first and second shell molecules have no measurable effect. (C) 2010 Elsevier B.V. All rights reserved.