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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