Biomass derived ionic liquids: synthesis from natural organic acids, characterization, toxicity, biodegradation and use as solvents for catalytic hydrogenation processes

Ionic liquids with natural organic derived anions (l-lactate, l-tartrate, malonate, succinate, l-malate, pyruvate, d-glucuronate, d-galacturonate) were easily prepared from tetrabutylammonium hydroxide and an excess of the corresponding acid with good yields. Their characterization was realized through classical NMR, IR, and elemental analysis techniques; their viscosity and TGA (thermogravimetric analysis) parameters were also determined. These ionic liquids showed good performance and recyclability in the selective catalytic hydrogenation of 1,5-cyclooctadiene (1,5-COD) into cyclooctene (COD) at room temperature under atmospheric H ₂ pressure. Antimicrobial toxicity assays toward a large panel of bacteria and fungi strains were also completed and biodegradation studies (Closed Bottle test, 28 days) were also performed.