LDH-DNA
Thyveetil, M-A.; Coveney, P.V.;
Greenwell, H.C.; Suter, J.L.,
“Computer Simulation Study of the
Structural Stability and Materials
Properties of DNA-Intercalated
Layered Double Hydroxides”, J.
Amer. Chem. Soc.,
DOI:10.1021/ja077679s (2008).
LDH-DNA
N = number of water/Al
Shows distortion of helix as
LDH dehydrates.
Compared % Watson-Crick
bonds still intact at high T (upto
500K) & P (upto 100 atm), DNA
significantly stabilised when
intercalated.
cf green rusts at hydrothermal
vents in Archean
LDH-DNA
LDH-Cl Materials Properties
Analysis of thermal undulations
and stress strain to give hard to
determine materials properties.
Thyveetil, M-A.; Coveney, P.V.;
Suter, J.L.; Greenwell, H.C.,
“Emergence of undulations and
determination of materials
properties in large-scale molecular
dynamics simulations of layered
double hydroxides”, Chem. Mater.,
19, 5510-5523 (2007).
LDH-Cl Materials Properties
The system exhibits emergent
properties, which are suppressed in
smaller-scale simulations.
Undulatory modes are caused by the
collective thermal motion of atoms in
the LDH layers. At length
scales larger than 20.7 Å, these
thermal undulations cause the LDH
sheets to interact and the oscillations
are damped. The thermal undulations
provide information about the
materials properties of the system.
In this way, we obtain values for the
bending modulus of 8.3 ± 0.4 x 10-19
J with in-plane Young’s
moduli of 63.4 ± 0.5 GPa for a
hydrated system and 139 ± 1 GPa
for the LDH sheets alone.
Cinnamate LDHs
Dimer
P recursor
Dimer
P recursor
(a
)
(d
)
(b
)
(e
)
(f
)
(c
)
Newman, S.P.; Greenwell, H.C.; Coveney, P.V.;
Jones, W. “Computer simulation of interlayer
arrangement in cinnamate intercalated layered double
hydroxides” J. Mol. Structure., 647, 1-3, 75 (2003)
Cinnamate LDHs
DFT - LDH-t-BuO catalysis
O
RÕ-C-OR + RÕÕ
-OH
ÕÕ
R-OH
HT+ -O-t-Bu
Catalyst
Step 3
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Alcoh
ol
Step 1
Transest erificat ion
HT+-OR
-+
O HT
RÕ-C-ORÕÕ
OR
Intermediate
t-BuOH
Step 2
O-- HT+-OR
RÕ-C-ORÕÕ
A
O
RÕ-C-ORÕÕ
Ester
DFT - LDH-t-BuO catalysis
Greenwell, H.C.; Stackhouse, S.; Coveney, P.V.; Jones, W. “A
density functional theory study of catalytic trans-esterification by
tert-butoxide MgAl anionic clays”. J. Phys. Chem. B. 107, 15,
3476-3485 (2003).
Postulate new reaction scheme:HT+ -NO3.xH2O
Catalyst
-
O
RÕ-C-OR + RÕÕ
-OH
ÕÕ
Transesterified
Product
Catalyst
Regeneration
O-t-Bu
Catalys
+..
HT OH HO-t-Bu
t
Catalyst
R-OH
Alcoh
ol
Step 1
P roduct
Formation
Step 3
Transesterification
HT+-OR +
t-BuOHÉ OH2
-+
O HT
RÕ-C-ORÕÕ
OR
+
t-BuOHÉ OH2
Intermediate
Step 2
O-- HT+-OR
RÕ-C-ORÕÕ
+ t-BuOHÉ OH2
O
RÕ-C-ORÕÕ
Ester