Modelling and Simulation of Ecotoxicity of Ionic Liquids Using QSAR

• Main Author: Masri, Asiah Nusaibah
• Format: Final Year Project
• Language: English
• Published: Universiti Teknologi PETRONAS 2010
• Subjects: TP Chemical technology
• Online Access: http://utpedia.utp.edu.my/10092/1/2010%20Bachelor%20-%20Modeling%20And%20Simulation%20Of%20Ecotoxicity%20For%20Ionic%20Liquids%20Using%20QSAR.pdf; http://utpedia.utp.edu.my/10092/
• Institution: Universiti Teknologi Petronas

Development of safer and environm~ntally friendly processes and products is required to achieve sustainable production and consumption patterns. Ionic liquids are compounds of high interest for industry because of their attractive properties as solvents, but the water solubility of these compounds may lead to aquatic pollution and related risks. Experimental toxicity evaluation (Daphnia magna EC50) is a measurement of aquatic toxicity but there are theoretically over l trillion ionic liquids, which makes it necessary to estimate their properties by means of quantitative structure-activity relationships (QSARs). In this work, a novel QSAR based on multilinear regression analysis method is applied to estimate the ecotoxicity of ionic liquids. A data set of Daphnia magna EC50 was assembled to develop a novel group contribution method for estimating the EC50 of ionic liquids. The ionic liquids are the combination of different anion and cation which are bromide (B(), chloride (Cr), tetrafluoroborate (BF 4), hexafluorophosphate (PF6-) and bis((trifluoromethyl)sulfonyl)imide (TF2N-) as anions with imidazolium (im), pyridinium (py), dirnethylamino pyridinium (DMApy), piperidino pyridinium (pipy), ammonium (N) and pyrrolidinium (pyr) as cations. However, due to complexicity of equations and time consuming to apply multilinear regression analysis by hand calculation, SPSS software 11.5 was used to apply the method. 44 data of ionic liquids were assembled and the results illustrated that the data range covered for log EC50 values in between 2.07 and -4.33. From the results, the contributions of anion, cation and alkyl substitutions has been established and found a good fitting value for predicting the EC50 with fl = 0.934, fladi = 0.910 and variance= 0.022. From the results, it can be concluded that the toxicity contribution in increasing order for anions ts hexafluorophosphate (PF6") < chloride (Cr) < tetrafluoroborate (BF4") < bis((trifluoromethyl)sulfonyl)irnide (TF2N), for cations is ammonium (N) < pyrrolidinium (pyr) < irnidazolium (im) < pyridinium (py) < dimethylamino pyridinium (DMApy) < piperidino pyridinium (pipy), and while for alkyl is R < R1 with R is long n-alkane chain and R1 is an additional short chain (methyl). However, further investigations are necessary to increase the number of data in the training set in order to reduce the confidence range of some group contributions (e.g., pyrrolidinium based ionic liquids). In addition, other cations and anions need to be studied to increase the application of the novel group contribution method.