Solvent bonding, factors affecting solubility

Another factor affecting the nucleophilicity of these ions is their solvation, particularly in protic solvents. A protic solvent is one that has acidic protons, usually in the form of O—H or N—H groups. These groups form hydrogen bonds to negatively charged nucleophiles. Protic solvents, especially alcohols, are convenient solvents for nucleophilic substitutions because the reagents (alkyl halides, nucleophiles, etc.) tend to be quite soluble. 

Factors Affecting Adhesive and Solvent Bonding 9.2.2.1 Solubility... 

Scheme 4 shows small-scale syntheses of solvated iodides [64-66]. Strongly donating solvents such as AT-methylimidazole (N-Melm) can accomplish complete anion/cation separation as shown for [Sm(N-MeIm)8]I3 under anaerobic conditions [67]. The chief factors which affect the often enhanced reactivity of the higher homologous halides are their higher solubility [48a], a thermodynamically more labile Ln-X bond (Fig. 4), the soft Lewis basicity of the iodide anion, and different solubility properties of the eliminated alkali metal salt. 

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