abstract
A new class of low bacterial and algal toxicity imidazolium and pyridinium halide ionic liquids (ILs), produced by a short synthesis from substituted mandelic acid derivatives is disclosed. Melting points for most of the ILs were above or close to 100 degrees C; however, one imidazolium example has a glass transition temperature below room temperature (RT; -3.3 degrees C). The series of 8 ILs enables an investigation of toxicity on modifying the heterocycle, aromatic ring substitution, ester group, and proximity of cation to aromatic ring present within mandelic acid constituent. Two pyridinium salts, methyl 2-(3,4-methylenedioxyphenyl)-2-pyridinium acetate, bromide salt and methyl 2-(3,4-methylenedioxyphenyl)-2-(2-pyridiniumacetoxy)acetate, bromide salt have low toxicity to all bacteria strains (including Vibrio fischeri), and freshwater green algae (C. Vulgaris and P. subcapitata) screened. All eight pyridinium and imidazolium ILs have low toxicity to Gram-positive (B. subtilis) and Gram-negative (E. coli, P. fluorescens, P. putida (CP1), and P. putgida (KT 2440)) bacteria strains, although a significant range in IC50 values was obtained. Mandelate derived ILs have EC50 (C. Vulgaris and P. subcapitata) values 10(3)-10(7) higher (less toxic) than other C14-C18 ionic liquids previously reported.
keywords
PHYTOPLANKTON SELENASTRUM-CAPRICORNUTUM; FUNCTIONALIZED SIDE-CHAINS; DIFFERENT HEAD GROUPS; ANTIMICROBIAL ACTIVITIES; VIBRIO-FISCHERI; ANTIBACTERIAL ACTIVITY; AQUATIC TOXICITY; DAPHNIA-MAGNA; ANION; BIODEGRADABILITY
subject category
Chemistry; Science & Technology - Other Topics; Engineering
authors
Ventura, SPM; Gurbisz, M; Ghavre, M; Ferreira, FMM; Goncalves, F; Beadham, I; Quilty, B; Coutinho, JAP; Gathergood, N
our authors
Fábio Miguel Mendes Ferreira
Science and Technology Manager
Sónia Patrícia Marques Ventura
Assistant ProfessorProjects
acknowledgements
N.G. is thankful for the support of Enterprise Ireland TD-2007-0328 for funding the work of I.B., Mo.G., and Mu.G. This material is also based upon works (N.G. and Mu.G.) supported by Science Foundation Ireland as part of the Solar Energy Conversion Strategic Research Cluster, Grant No. [07/SRC/B1160] which the authors acknowledge. This work was partly funded by Fundacao para a Ciencia e a Tecnologia (FCT) through the project PTDC/AAC-AMB/119172/2010 and the project Pest-C/CTM/LA0011/2011. The authors also are thankful for the financial support from FCT for the Postdoctoral grant SFRH/BDP/79263/2011 of S.P.M.V.