Special Issue on THEORETICAL CHEMISTRY/CHEMICAL DYNAMICS

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Special Issue on THEORETICAL CHEMISTRY/CHEMICAL DYNAMICS

REGULAR ARTICLE

Microstructures and their Lifetimes in Acetamide/Electrolyte Deep Eutectics: Anion Dependence

SUMAN DAS1, BISWAROOP MUKHERJEE2 and RANJIT BISWAS1,2,

1Chemical, Biological and Macromolecular Sciences, and 2Thematic Unit for Excellence – Computational Materials Science, S N Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata, West Bengal700098, India

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Table of Contents:

Force field parameters of acetamide, nitrate, perchlorate, lithium and bromide (Table S1) ------2

Density comparison between simulations and experiments (Table S2) ------8

Distance distribution between the oxygen and nitrogen atom belonging to different pair of acetamide molecules (Figure S3) ------9

Multi-exponential fitting parameters for cluster lifetime distribution of all the DESs at both the temperatures (Table S4)------10

Table S1: Force field parameters of acetamide, nitrate, perchlorate, lithium and bromide are given below:

CHARMM representation of acetamide, CH3CONH2. Atom types and interaction parameters tabulated below.a

Partial charges andLJ Parameters for Acetamide

Atom Type (e) (Kcalmol-1) (Å)

C3 -0.27 0.0803.67

H1 0.09 0.0222.35

C6 0.55 0.0703.57

OC2 -0.55 0.1203.03

N1 -0.64 0.2003.30

HO 0.32 0.0460.40

Bond force constant for Acetamide

Bonds (Å) (KCalmol-1Å-2)

C3-H1 1.11 322

C3-C6 1.52 200

C6-OC2 1.23 650

C6-N1 1.36 430

N1-HO 1.00 480

Angle force constant for Acetamide

Angles (deg) (Kcalmol-1rad-2)

H1-C3-H1 108.4 35.5

H1-C3-C6 109.5 33.0

C3-C6-OC2 121.0 15.0

C3-C6-N1 116.5 50.0

OC2-C6-N1 122.5 75.0

C6-N1-HO 120.0 50.0

HO-N1-HO 120.0 23.0

Dihedral force constant for Acetamide

Dihedral (Kcalmol-1) n δ (deg)

H1-C3-C6-OC2 0.05 6 180.0

H1-C3-C6-N1 0.05 6 180.0

C3-C6-N1-HO 1.4 2 180.0

OC2-C6-N1-HO 1.4 2 180.0

a) The above representation and interaction parameters are from MacKerell Jr, A. D.; Wiorkiewicz-Kuczera, J.; Karplus, M.An all-atom empirical energy function for the simulation of nucleic acids.J. Am. Chem. Soc.1995,117, 11946-11975.

Representation of Nitrate ion. Atom types and interaction parameters are shown below.

Partial Atomic Charges and Lennard-Jones Parametersb

Atom Type (e) (Kcalmol-1) (Å)

NO 0.95 0.0807 3.06

O1,2,3 -0.65 0.1457 2.77

b) The Partial atomic charges and Lennard-Jones Parameters are from Lopes, J. N. C.; Deschamps, J.; Padua, A. A. H. Modeling Ionic Liquids Using a Systematic All-Atom Force Field. J. Phys. Chem. B2004,108,2038-2047.

Bond force constant parametersc

Bonds (Å) (KCalmol-1Å-2)

NO-O1/O2/O3 1.2599 525.00

Angle force constant parametersc

Angles (deg) (Kcalmol-1rad-2)

O-NO-O 120.00 120.00

c) The above interaction parameters are from Cadena, C.; Maginn, E. J.Molecular Simulation Study of Some Thermophysical and Transport Properties of Triazolim-Based Ionic Liquids. J. Phys. Chem. B2006, 110, 18026-18039.

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Representation of perchlorate ion. Atom types and interaction parameters are shown below c

Partial Atomic Charges and Lennard-Jones Parameters

Atom Type (e) (Kcalmol-1) (Å)

Cl 1.342 0.1481 3.770

O1,2,3,4 -0.5855 0.1457 2.771

Bond force constant parameters

Bonds (Å) (KCalmol-1Å-2)

Cl-O1/O2/O3/O4 1.5006 365.00

Angle force constant parameters

Angles (deg) (Kcalmol-1rad-2)

O-Cl-O 109.47 125.00

Interaction parameters for Li+ and Br-are tabulated below d

Partial Atomic Charges and Lennard-Jones Parameters

Atom Type (e) (Kcalmol-1) (Å)

Li 1.00 0.0005 2.87

Br -1.00 0.7100 4.28

d) The above interaction parameters are from Jensen, K. P.; Jorgensen W. L. Halide, Ammonium, and Alkali Metal Ion Parameters forModeling Aqueous Solutions.J. Chem. Theory Comput.2006, 2, 1499-1509.

Table S2: Density comparison between simulations and experiments.

Mixtures / Experimental Density
(gm/cc); ~313 K / Simulated Density
(gm/cc); 303 K / % Deviation / Experimental Density
(gm/cc); ~343 K / Simulated Density
(gm/cc); 350 K / % Deviation
CH3CONH2+LiBr / 1.237e / 1.34 / 7.68 / - / 1.30 / -
CH3CONH2+LiNO3 / 1.17e / 1.30 / 10 / - / 1.17 / -
CH3CONH2+LiClO4 / 1.23f / 1.30 / 5.4 / 1.20f / 1.22 / 1.6

e) The above experimental density is obtained from Biswas, R.; Das, A.; Shirota, H. Low-Frequency Collective Dynamics in Deep Eutectic Solvents of Acetamide and Electrolytes: A Femtosecond Raman-Induced Kerr Effect Spectroscopy Study. J. Chem. Phys.2015, 141,134506-1-134506-11. Note that the experimental densities were measured at 313 K and this explains the relatively large deviations between simulations and experiments observed here.

f) The above experimental density is obtained from Guchhait, B.; Das, S.; Biswas, R. Interaction and Dynamics of (Alkylamide + Electrolyte) Deep Eutectics: Dependence on Alkyl Chain-length, Temperature and Anion Identity.J. Chem Phys, 2014,140, 104514-1-104514-12.

Figure S3: The upper panel shows the distance distribution between the oxygen and nitrogen atom belonging to different pair of acetamide molecules whose centre of mass distance lies within 7Å. The lower panel shows the angle () distribution for same. Both the distributions are calculated for all DESs at 303 K. The details are discussed in the text.

Table S4:Multi-exponential fitting parameters for cluster lifetime distribution of all the DESs at both the temperatures.

/ / (ps) / / (ps) / / (ps) / / (ps) / β / (ps)
/ / / 0.19 / 1.2 / 0.26 / 19.0 / 0.45 / 140.8 / 0.10 / 15267.8 / 1.0 / 1595.3
/ 1.0 / 909.1 / - / - / - / - / - / - / 1.0 / 909.1
/ 0.07 / 10.4 / 0.26 / 81.3 / 0.27 / 909.1 / 0.40 / 2000.0 / 1.0 / 1067.3
/ / 0.18 / 1.0 / 0.20 / 7.2 / 0.59 / 36.4 / 0.03 / 555.5 / 1.0 / 39.8
/ 0.07 / 8.0 / 0.93 / 131.6 / - / - / - / - / 1.0 / 123.0
/ 0.30 / 11.1 / 0.70 / 78.7 / - / - / - / - / 1.0 / 58.4
/ / / 0.19 / 1.0 / 0.27 / 10.0 / 0.41 / 53.7 / 0.13 / 625.0 / 1.0 / 106.1
/ 0.26 / 24.5 / 0.74 / 666.7 / - / - / - / - / 1.0 / 500.0
/ 1.0 / 357.1 / - / - / - / - / - / - / 1.0 / 357.1
/ / 0.19 / 1.0 / 0.22 / 6.8 / 0.49 / 29.9 / 0.10 / 137.0 / 1.0 / 30.0
/ 0.05 / 0.9 / 0.11 / 5.5 / 0.60 / 39.4 / 0.24 / 175.4 / 1.0 / 66.4
/ 0.11 / 1.4 / 0.26 / 11.5 / 0.50 / 63.7 / 0.13 / 285.7 / 1.0 / 72.1
/ / / 0.23 / 1.2 / 0.40 / 16.2 / 0.28 / 97.1 / 0.09 / 1000.0 / 1.0 / 124.0
/ 0.15 / 1.0 / 0.15 / 9.3 / 0.35 / 104.1 / 0.35 / 555.6 / 1.0 / 232.5
/ 0.10 / 250.0 / 0.90 / 5000.0 / - / - / - / - / 1.0 / 4525.0
/ / 0.21 / 1.0 / 0.26 / 7.1 / 0.46 / 27.6 / 0.07 / 145.0 / 1.0 / 24.9
/ 0.17 / 0.7 / 0.17 / 6.1 / 0.23 / 37.9 / 0.43 / 153.8 / 1.0 / 76.0
/ 0.07 / 1.7 / 0.19 / 29.3 / 0.34 / 250.0 / 0.40 / 2000.0 / 1.0 / 890.7

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