SupramolekulSupramolekuláárna štruktúra v rna štruktúra v roztokoch a zmesiach kvapalínroztokoch a zmesiach kvapalín
_______________________Seminár ÚEF 25.septembra 2007
1.) M. Sedlák: Large-Scale Supramolecular Structure in Solutions of Low Molar Mass Compounds and Mixtures of Liquids: I. Light Scattering Characterization. J. Phys. Chem. B, 110 (9), 4329 -4338, 2006.
2.) M.Sedlák: Large-Scale Supramolecular Structure in Solutions of Low Molar Mass Compounds and Mixtures of Liquids: II. Kinetics of the Formation and Long-Time Stability. J. Phys. Chem. B, 110 (9), 4339 -4345, 2006.
3.) M. Sedlák: Large-Scale Supramolecular Structure in Solutions of Low Molar Mass Compounds and Mixtures of Liquids: III Correlation with molecular properties and interactions. J. Phys. Chem. B, 110 (9), 13976-13984, 2006.
M. Sedlák: Large-scale supramolecular structure in solutions of polar and ionic molecules and macromolecules, ESF Exploratory workshop: self-assembly of guanosine, Bled, Slovenia, 13.9. -15.9.2006
M. Sedlák: Large-scale supramolecular structures, First Annual (Inaugural) Conference onThe Physics, Chemistry and Biology of Water 2006, Brattleboro, Vermont, USA, 26.10. -29.10., 2006
g(r) - pair correlation functiong(r) - pair correlation function
r r
SLS: Space resolution ~ 1/q
q: scattering vector
q = (4n/0)sin(/2)
r ~ 1/q ~ 20 - 2 000 nm
DLS resolution:
Space: 1 - 5 000 nm
Time: 100 ns - seconds
Static and Dynamic Laser Light Scattering
Static Light ScatteringStatic Light Scattering
Measured quantities:
• angular dependence I() or I(q), q = (4n/0)sin(/2)
yields: structural information d ~ 1/q ~ 20 - 2000 nm
• absolute values I(0)
yields: particle mass
particle interactions
Dynamic Light ScatteringDynamic Light Scattering
Measured quantity
• frequency dependence I(f)
f/f0 = 10 - 107 Hz / 1015 Hz
= 10-8 - 10-14
f
f0
f, Hz
I
Various types of dynamics: Spatial resolution via dynamics:
• translational diffusion Diffusion ~ 1/R
• rotational diffusion 1 nm - 5000 nm
• non-diffusive relaxations
E~
I
time
<E
>
Time autocorrelation of scattering signal
)()()( *)1( tEtEg
d
ifegfI
)(2
1)( )1(
~ 100ns - seconds
0.4 M MgSO4 (aqueous)
I/IB = Af + As
Df = coupled diffusion of cations and anions (Nernst-Hartley)
M. Sedlák, in ”Physical Chemistry of Polyelectrolytes” (T. Rageva ed.), Marcel Dekker, New York, 2001, p.1-58M. Sedlák, Langmuir 15 (1999), 4045-4051.
Rationale
• Large inhomogenities in refractive index must exist (large means ~ q-1 >> molecular dimensions or intermolecular distances)
• These are responsible for the slow dynamics
• Due to inhomogenities in the local concentration of solute and/or due to inhomogenities in the local arrangement of asymmetric solute molecules
Light scattering characterization of large-scale inhomogeneous structure
Random two-phase system (Debye-Bueche model)? Spatial correl. function <n(0)n(r)> ~ e-r/a
Discrete structures
• self-similar (fractal) ?
• asymmetric (depolarized scattering) ?
• spherical or close-to-spherical
Size distribution by ORT Optimized regularization technique
(O. Glatter et al.)
Spherical or close-to-spherical discrete objectsSpherical or close-to-spherical discrete objects
20 000 g
Number of solute particles per domain
R = 30 nm R = 300 nm
Lower estimate ~ 104 ~ 107
Upper estimate ~ 106 ~ 109
Number of solute particles per domain
R = 30 nm R = 300 nm
Lower estimate ~ 104 ~ 107
Upper estimate ~ 106 ~ 109
H2O + acetic acid
0 2 4 6 8 10 120.0
0.1
0.2
0.3
0.4
0.5
B
A
I/IB (9
0o )
t, min
0 10 20 30 400
1
2
3
4
5
I/IB (9
0o )
t, min
H2O
acetic acid
0 2 4 6 8 10 12
t, min
0.5
0.4
0.3
0.2
0.1
0.0I
/ IB (
90°)
0 2 4 6 8 10 120.0
0.1
0.2
0.3
0.4
0.5
B
A
I/IB (9
0o )
t, min
0 10 20 30 400
1
2
3
4
5
I/IB (9
0o )
t, min
H2O + acid
0 10 20 30 40
t, min
5
4
3
2
1
0
I / I
B (
90°)
c = 6 mass % of acid
Kinetics of the supramolecular domain formationKinetics of the supramolecular domain formation
H2O + DMSO
0.0 0.2 0.4 0.6 0.80.02
0.1
1
8
As
sin2(/2)
8
1
0.1
0.02 0.0 0.2 0.4 0.6 0.8
sin 2(/2)
AS
0 100 200 3000
2
4
6
8
0
75
150
225
300
Rh,
nm
As (
37.5
o )t, days
8
6
4
2
0
AS (
37.5
°)
300
225
150
75
0 100 200 300
t, days
0
Rh,
nm
c = 10.5 mass % of DMSO
Kinetics of the supramolecular domain formationKinetics of the supramolecular domain formation
Monovalent (1:1) electrolytes Multivalent electrolytes
0.0 0.2 0.4 0.6 0.8
0.1
1
10
100
200
As /
Af
sin2(/2)
0.0 0.2 0.4 0.6 0.8
sin 2(/2)
200
100
10
1
0.1
As / Af
0.0 0.2 0.4 0.6 0.8
0.1
1
10
100
200A
s / A
f
sin2(/2)
0.0 0.2 0.4 0.6 0.8
sin 2(/2)
200
100
10
1
0.1
As / Af
c = 0.4M
Aqueous solutions:
AlCl36H2O
Al(NO3)39H2O
MgSO47H2O
CdSO48/3H2O and
Al2(SO4)318H2O
As= 0 MgSO47H2O in methanol
KCl in water
NaI in water
KI in water
KI in glycerine
KI in ethyleneglycol
KI in dimethylformamide
KI in dimethylsulfoxide
As= 0 KI in methanol
As= 0 KI in acetonitrile
Effect not due to Coulomb attraction
• no correlation with ion valency
• no correlation with solvent dielectric permittivity
Comparison of osmotic coefficients of monovalent and multivalent salts in selected solvents.
.
Simple ion pairing due to Coulomb attraction
• correlation with ion valency
• correlation with solvent dielectric permittivity
Aqueous solutions of citric acid ionized to different degrees:
no ionization (), 4% (), 38% (), 60% (), and 90% ionization ()
CH2 COOH
C COOH
CH2 COOH
OH
citric acid
Effect not due to Coulomb attraction
•no correlation with ion valency
Scattering from supramolecular domains in aqueous solutions of selected non-ionic solid compounds
urea
pyrogallol
hydroquinone
D-glucose
saccharose
OH
OH
OH
c = 4.5 mass %
OHOH
O C30
NH2
NH2
OCH2OH
HH
OHH
OH
OH
HOH
H
OCH2OH
HH
OHH
OH
OH
H
H
O
O
OH
H
H
OHCH2OH
HCH2OH
Scattering from supramolecular domains in aqueous liquid mixtures
dimethylsufoxide
dioxane
acetonitrile
acetic acid
methanol
ethanol
ethyleneglycol
glycerol
CH3
SO
CH3
O
O
CH3 NC
CH3 COOH
CH2OH CH2 OH
CH2OH CH
OH
CH2 OH
CH3 OH
CH2 OHCH3
Mixtures of nonpolar or weakly polar compounds
methanol-benzene
10
5
1 0.0 0.2 0.4 0.6 0.8 1.0
sin 2(/2)
I / I
B
methanol-benzene
-4 -3 -2 -1 0 1 2
log (t, ms)
0.5
0.4
0.3
0.2
0.1
0.0
g(1) (t
)
t A(t
), a
.u.
Mixtures of strongly polar compounds
Protic mixtures: at least one component protic O-H, N-H, S-H, Halogen-H
O
O
O
O
H
OHH
OHOO
H
OH
HOH
H
OH
H
OH
............
...
...
...
...
...
...
...
...
H O
H
H O
H
H OH
H
O
HH
O
H
K+
I
IH
O
H
H
O
H
H
O
H
......
.
...
...
.........
..
...
....
..
O C30
NH2
NH2
urea
water methanol
As/Af (37.5°) As/Af
0.4M KI 6.5 0.92 0 0.79
0.12M KBr 10.2 0.93 0 0.81
0.4M MgSO47H2O 118 0.57 0 0.20
10 mass % dioxane 155 ---- 0 ----
20 mass % acetonitrile > 30 ---- 0 ----0.0 0.2 0.4 0.6 0.80.03
0.1
1 E
I/I B
sin2(/2)
0.3
1
10 D
I/I B
0.3
1
10
C
I/I B
0.01
0.1
B
I/I B
0.1
1
A
I/I B
1
0.1
0.1
0.0110
1
0.3
10
1
0.3
1
0.1
0.030.0 0.2 0.4 0.6 0.8
sin 2(/2)
I / I
B
I /
I B
I /
I B
I /
I B
I /
I B
Scattering from supramolecular domains in dioxane mixtures
water
ethyleneglycol
glycerol
0.0 0.2 0.4 0.6 0.8
0.01
0.1
1
10
As
sin2(/2) As = 0 methanol
As = 0 ethanol
CH2OH CH2 OH
CH2OH CH
OH
CH2 OH
H O H
O
O
CH3 OH
CH2 OHCH3
0.0 0.2 0.4 0.6 0.8
sin 2(/2)
10
1
0.1
0.01
AS
OCH2OH
HH
OHH
OH
OH
HOH
H glucose
OCH2
HH
OHH
OH
OH
H
H
OO
CH2
HH
OHH
OH
OH
H
H
OO
CH2
HH
OHH
OH
OH
H
H
O
dextran
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