Supporting Information for

Environmentally benign tetramethylguanidinium cation based ionic liquids

Akhil Pratap Singh,

1, 2 Devilakshmi Sithambaram,

1 Rutvi Sanghavi,

1 Piyush Kumar Gupta,

1

Rama Shanker Verma,1

Mukesh Doble,1

Ramesh L. Gardas,2

and Sanjib Senapati1,*

1Bhupat and Jyoti Mehta School of Biosciences, Department of Biotechnology,

2Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India

Phone: +91-44-2257-4122. Fax: +91-44-2257-4102.

E-mail: sanjibs@iitm.ac.in.

Electronic Supplementary Material (ESI) for New Journal of Chemistry.This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2017

Figure S1. The 1H NMR (500MHz, D2O) spectra of [TMG][BEN].

Figure S2. The 1H NMR (500MHz, D2O) spectra of [TMG][SAL].

Figure S3. The 1H NMR (500MHz, D2O) spectra of [TMG][LAC].

Figure S4. The 1H NMR (500MHz, D2O) spectra of [TMG][DHP].

Figure S5. The 1H NMR (500MHz, D2O) spectra of [TMG][NO3].

Figure S6. The 1H NMR (500MHz, D2O) spectra of [TMG][HCOO].

Figure S7. The 1H NMR (500MHz, D2O) spectra of [TMG][ACE].

Figure S8. The 1H NMR (500MHz, D2O) spectra of [TMG][PRO].

Figure S9. The 1H NMR (500MHz, D2O) spectra of [TMG][BUT].

Figure S10. The 1H NMR (500MHz, D2O) spectra of [TMG][VAL].

Table S1. Thermal Properties of the [TMG] cation based ILs: Melting (Tm) and

Decomposition (Tdec), Temperatures

Ionic Liquids Tm (C) Tdec (C)

[TMG][BEN] 110 208

[TMG][SAL] 125 235

[TMG][LAC] <-50 168

[TMG][DHP] > 150 230

[TMG][NO3] 86 238

[TMG][HCOO] 75 180

[TMG][ACE] 95 164

[TMG][PRO] 60 154

[TMG][BUT] 65 150

[TMG][VAL] 55 167

Figure S11. Effect of increasing concentration of [TMG] based ILs on the viability of

HEK-293 cell line after 24 hours of exposure. Results are shown for ILs with (a) varying

cation-anion combination, and (b) varying anion side-chain. Color scheme: (---■---)

[TMG][BEN], (---●---) [TMG][SAL], (---▲---) [TMG][LAC], (---▼---) [TMG][DHP], (--

-◄---) [TMG][NO3], (---■---) [TMG][HCOO],(---●---) [TMG][ACE], (---▲---

)[TMG][PRO], (---▼---) [TMG][BUT], and (---◄---) [TMG][VAL].

(a)

(b)

Figure S12. Effect of increasing concentration of [TMG] based ILs on the viability of HEK- 293 cell line after 48 hours of exposure. Results are shown for ILs with (a) varying cation-

anion combination, and (b) varying anion side-chain. Color scheme is similar to Fig. S1.

(a)

(b)

Figure S13. Viability of confluent DLD-1 cells exposed to different ILs at 10 mM

concentration for (a) 24 hours and (b) 48 hours. Data represents mean ± SD of two

independent experiments. The t-test was performed to obtain a level of significance from

control. Statistical significance between various ILs were denoted by **** p<0.0001, ***

p<0.001, ** p<0.01, * p<0.05 with respect to control for each IL.

(a)

(b)

Figure S14. Biodegradability assessment of the selected ILs using using Bacillus subtilis

NCIM 2718. 1H NMR spectra at the beginning and after 7 days of incubation for (a)

[TMG][PRO] (7 mM), (b) [TMG][BUT] (15 mM) and (c) [TMG][VAL] (7 mM).