SUPPORTING INFORMATION

Transcription

1 SUPPRTING INFRMATIN The Water Bend+Libration Combination Band is an Intrinsic, Collective, and Strongly Solute-Dependent Reporter on the Hydrogen Bonding Network of Liquid Water Pramod Kumar Verma, Achintya Kundu, Matthew Puretz, Charvanaa Dhoonmoon, riana S. Chegwidden, Casey H. Londergan *,, Minhaeng Cho * Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Seoul 02841, Republic of Korea Department of Chemistry, Korea University, Seoul 02841, Republic of Korea. Department of Chemistry, Haverford College, 370 Lancaster Avenue, Haverford, Pennsylvania * Corresponding author, clonderg@haverford.edu, mcho@korea.ac.kr The supporting information has following contents, (1) Temperature dependent FTIR spectra of water HH bend and combination band (Figure S1). (2) Experimental and data manipulation procedure for density-normalized analysis of combination band spectra (Figure S2, and S3). (3) FTIR spectra of water combination band at various temperatures and five different concentration of sodium chloride (Figure S4). (4) Both peak normalized and non-normalized concentration dependent FTIR absorption spectra of water combination band in aqueous solution of sodium/anions (Figure S5, and S6). (5) Both peak normalized and non-normalized concentration dependent FTIR absorption spectra of water combination band in aqueous solution of cations/chloride (Figure S7, and S8). (6) Concentration dependent FTIR (non-normalized) absorption spectra of water combination band of aqueous solution urea and GdnHCl (Figure S9) (7) FTIR absorption spectra of liquid tetramethylurea (TMU) and diethylene glycol dimethyl ether (DEGDME) in H stretch vibration band ( cm -1 ) region (Figure S10). (8) Both peak normalized and non-normalized concentration dependent FTIR absorption spectra of water combination band of aqueous solution of sorbitol, trimethylglycine (TMG) and glycine (Figure S11, and 12) (9) Mean frequency of water combination band of different wt% of poly(ethylene glycol) dimethyl ether (PEGDME) and diethylene glycol dimethyl ether (DEGDEM; Figure S13). (10) FTIR spectra of D stretching band of HD (5%) of different wt% of poly(ethylene glycol) dimethyl ether (PEGDME) and diethylene glycol dimethyl ether (DEGDEM; Figure S14). (11) Both peak normalized and non-normalized FTIR absorption spectra of water combination band in various (0.3M) micelles (Figure S15, and S16). Present address Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi , India S1

2 FTIR spectra of water HH bend and combination band at different temperatures. HH bend 1 Temperature ( o C) Combination band Figure S1. Temperature dependent FTIR absorption spectra of water covering HH bend and bend-libration combination. S2

3 Density-normalized spectral subtractions. To clearly determine the origin of discrete or narrow features in the combination band region, a densitynormalized spectral subtraction was performed. The presence of solute changes the density of water in each solute-containing sample, so a subtraction of the combination band from pure water must be performed while taking into account the density of water and scaling to the number of water molecules present between the windows of the calcium fluoride cell infrared cell. The resulting spectrum is a soluteinfluenced difference spectrum whose features clearly indicate by their solute concentration dependence whether they arise from shifts or intensity changes in the solvent combination band, the solute, or a signal that depends on both the solvent and the solute (i.e. water-solute interaction bands). Method: Each solute solution was weighed in a pre-weighed 2 ml volumetric flask to determine the density of the solution. The known fractional mass of the solute was subtracted from the mass of the solution to find the mass of water and thus the density of water in each sample. The density of water was found using its mass and the volume of the solution. We found the ratio of the density of the water solvent to that of pure water. The differential absorption spectrum of the solution was found by subtracting a density-normalized version of the spectrum of pure, deionized water from the solution spectrum. The following features were observed in these difference spectra: Combination band frequency shifts appeared as broad first-derivative type features Combination band intensity changes appeared as positive or negative displacements along the y- (.D.) axis Solute bands appeared as positive, frequency-static features whose intensities varied linearly with solute concentration Solvent-solute bands appeared either as positive, frequency-static features whose intensities did not vary linearly with concentration, or as features whose frequencies depended clearly on solute concentration Such a procedure can be used to clearly identify the origin of features that appear in the combination band region of concentrated aqueous solution. Two examples of density-normalized difference spectra subtractions are shown below, with brief discussion of what they show: S3

4 Figure S2. Density-normalized difference spectrum in the combination band region for ammonium chloride as solute. The broad, first-derivative feature whose intensity increases with ammonium chloride concentration indicates an increasing shift to lower wavenumber with higher solute concentration. The baseline shift indicates an increase in the intensity of the water combination band as it shifts to lower frequency. There are no discrete features appearing in this difference spectrum. Figure S3. Density-normalized difference spectrum in the combination band region for guanidinium chloride as solute. The broad, first-derivative feature indicates a slight shift to lower wavenumber with higher solute concentration. The baseline shift indicates a decrease in the intensity of the water combination band at higher concentration of solute. There are some weak, positive discrete features (specifically one at about 2210 cm -1 ) that appear with increasing solute concentration: their frequencies do not change and their intensities depend linearly on the solute concentration, so these features are assigned to the denaturant itself. There are no water association bands in this spectrum (as with most difference spectra analyzed in this study). S4

5 FWHM of water combination band / cm -1 FTIR spectra of water combination band at different temperatures and five different concentration of sodium chloride Temperature / o C (C) 56 o C 5M 14 o C 0M 2400 (D) [NaCl] / moll Figure S4. Temperature dependent FTIR spectra of water combination bands at 20 µm pathlength. FTIR spectra of water combination band at 40 µm pathlength in aqueous solutions of sodium chloride. The FWHM obtained from Lorentzian fitting of the water combination band at different temperature (C) and various concentration of NaCl (D). S5

6 (normalized) Concentration dependent FTIR spectra of water combination band of aqueous solution of nine different anions (sodium salt) (C) C -2 CH 3 C - 2 S (D) S 2-2 (E) (F) Cl - 3 F - (G) Br - (H) I - (I) Cl M 1 M 2 M 3 M 5 M Figure S5. FTIR (peak normalized) absorption spectra of water combination band of aqueous solution of sodium carbonate, sodium acetate, sodium sulfate (C), sodium thiosulfate (D), sodium fluoride (E), sodium chloride (F), sodium bromide (G), sodium iodide (H) and sodium perchlorate (I). (C) C -2 CH 3 3 C - 2 S -2 4 (D) (E) (F) S 2-2 F - 3 Cl - (G) (H) Br - I - (I) Cl M 1 M 2 M 3 M 5M Figure S6. FTIR (non-normalized) absorption spectra of water combination band of aqueous solution of sodium carbonate, sodium acetate, sodium sulfate (C), sodium thiosulfate (D), sodium fluoride (E), sodium chloride (F), sodium bromide (G), sodium iodide (H) and sodium perchlorate (I). S6

7 (normalized) (normalized) Concentration dependent FTIR spectra of water combination band of aqueous solution of eight different cations (chloride salt) (C) (D) Cs + Rb + K + Na + (E) Li + (F) Ca +2 (G) Mg +2 (H) Zn +2 0 M 1 M 3 M 5 M Figure S7. FTIR (peak normalized) absorption spectra of water combination band of aqueous solution of cesium chloride, rubidium chloride, potassium chloride (C), sodium chloride (D), lithium chloride (E), calcium chloride (F), magnesium chloride (G) and zinc chloride (H). 0.6 Rb (C) K + (D) Na + Cs + (E) Li + (F) Ca +2 (G) Mg +2 (H) Zn +2 0 M 1 M 3 M 5 M Figure S8. FTIR (non-normalized) absorption spectra of water combination band of aqueous solution of cesium chloride, rubidium chloride, potassium chloride (C), sodium chloride (D), lithium chloride (E), calcium chloride (F), magnesium chloride (G) and zinc chloride (H). S7

8 FTIR spectra of water combination band of aqueous solution of urea and GdnHCl. 1M Urea 3M Urea 6M Urea 8M Urea 1M GdnHCl 3M GdnHCl 6M GdnHCl Figure S9. FTIR (non-normalized) absorption spectra of water combination band in aqueous solution of urea, and GdnHCl. FTIR spectra of liquid tetramethyl urea (TMU) and liquid diethylene glycol dimethyl ether (DEGDME) in H stretch band region. 5 0 TMU DEGDME Figure S10. FTIR absorption spectra of tetramethyl urea (TMU) and diethylene glycol dimethyl ether (DEGDME) in the H stretching band region ( cm -1 ). H stretching region exhibits a broad poorly resolved band which consists of nonhydrogen bonded H groups (3615 cm -1 ) and hydrogen bonded H groups (3420 cm -1 ; this band subsist of symmetric and antisymmetric stretching modes) and to overtone of the symmetric bending vibrations of water molecules (3250 cm -1 ). Note that H stretching vibration mode frequencies are shifted to lower wavenumber for water molecules forming stronger H- bonds than in bulk water. In case of neat TMU, there are bands appearing in 3549, 3487 and 3283 cm -1 confirming presence of residual water in the liquid TMU solution. In case of DEGDME, the bands in the H stretching region are very weak and hence we believe that water is negligibly present in the liquid DEGDME solution. S8

9 (normalized) FTIR spectra of water combination band of aqueous solution of sorbitol, trimethylglycine (TMG) and glycine M Sorbitol 3M Sorbitol 5M sorbitol 0.5 1M TMG 3M TMG 5M TMG 0.5 (C) 1M Glycine 3M Glycine Wavenumber /cm -1 Figure S11. FTIR (peak normalized) absorption spectra of water combination band in aqueous solution of sorbitol, trimethylglycine and glycine (C). The FTIR spectra of water combination band in neat water is shown in cyan shaded area. 0 M 1 M 3 M 5 M Sorbitol TMG (C) Glycine Wavenumber /cm -1 Figure S12. FTIR (non-normalized) absorption spectra of water combination band in aqueous solution of sorbitol, trimethylglycine and glycine (C). S9

10 (normalized) (normalized) Mean frequency / cm -1 First moment frequency of water combination band as a function of poly(ethylene glycol) dimethyl ether (PEGDME) and diethylene glycol dimethyl ether (DEGDME) % 30% 50% 70% 80% 85% PEGDME Crowder DEGDME Figure S13. Mean frequency of water combination band of aqueous solutions of poly(ethylene glycol) dimethyl ether (PEGDME) and diethylene glycol dimethyl ether (DEGDEM). The concentration of PEGDME and DEGDME varies from 10 wt% to 85 wt% of crowder. The horizontal dash line corresponds to mean frequency of combination band in neat water. FTIR (normalized) spectra of the D stretch of HD (5%) of different wt% of poly(ethylene glycol) dimethyl ether (PEGDME) and diethylene glycol dimethyl ether (DEGDME). 0.6 D 10% 30% 50% 70% 80% 85% PEGDME DEGDME Figure S14. FTIR (normalized) spectra of the D stretch mode of HD in different wt% of PEGDME and DEGDME. Cyan shaded area is for the D stretch of HD. S10

11 (normalized) FTIR spectra of the water combination band in various micelles (0.3M). 0.3M SDS 0.3M SDBS 0.3M TX M DTAB 0.6 Figure S15. FTIR (peak normalized) spectra of the water combination band (peak normalized) in aqueous solution of 0.3M anionic sodium dodecyl sulfate (SDS), 0.3M anionic sodium dodecylbenzenesulfonates (SDBS), 0.3M non-ionic polyethylene glycol tert-octylphenyl ether (TX-100) and 0.3M cationic dodecyltrimethylammonium bromide (DTAB). Cyan shaded area corresponds to water combination band in neat water. 0.3M SDS 0.3M SDBS 0.3M TX M DTAB Figure S16. FTIR (non-normalized) spectra of the water combination band (non-nornalized) in aqueous solution of 0.3M anionic sodium dodecyl sulfate (SDS), 0.3M anionic sodium dodecylbenzenesulfonates (SDBS), 0.3M non-ionic polyethylene glycol tert-octylphenyl ether (TX-100) and 0.3M cationic dodecyltrimethylammonium bromide (DTAB). S11