Ionic Liquids containing metallic nucleus

In this PhD thesis, new methods to solubilize metal salts in ionic liquids (ILs) were developed and the behavior of the new metal containing ILs was studied. To incorporate metals in ILs, till now, anions (chloride, bromide, dicyanamide) able to give strong complexes with metals or the introduction of specific functional groups on cation or anion able to interact with the metal cation have been used. In all these cases, chemical nature of metal is changed by the interaction with other atoms and formation of new chemical bonds. To have weakly coordinated or relatively “free” cations in ILs, new kind of salts, with very soft anions have been used. New metallic salts, with Tf2N- as anion, were dissolved in suitable ionic liquids obtaining high concentrated solutions. Experiments performed using different classes of ILs evidenced that ILs having the same anion of the added metal salt generally assure a relevant solubility. A new common anion effect was invoked. The physical-chemical properties of the metal containing solutions were determined as function of concentration and temperature. Moreover, new ILs bearing cations or anions able to interact with the metal center were synthesized. In this contest basic 1,4-diazabicyclo[2.2.2]octane (dabco) based ILs bearing different alkyl chains and having as counter anion dicyanamide were synthesized and characterized as well as imidazolium based ILs functionalized with hydroxyl substituted alkyl chains (glycerol) or polymerizable groups (allyl, vinyl and styril groups). The interaction between dicyanamide anion and metals, especially in copper-catalyzed reactions was investigated. Since the purity degree of ILs is very important for their application in synthesis, especially when ILs must be used in metal catalyzed reactions, or when kinetics studies have to be performed, a new cheap and easily accessible method to purify ILs from organic solvents and unreacted reagents was developed and applied. Highly “pure” ILs, so generated, were used in the kinetic study of oxidation reactions performed using with singlet oxygen.