Microwave spectroscopy of biomimetics molecules

blaredsnottyΤεχνίτη Νοημοσύνη και Ρομποτική

15 Νοε 2013 (πριν από 3 χρόνια και 10 μήνες)

95 εμφανίσεις

Microwave spectroscopy of

biomimetics molecules



I. Kleiner


Laboratoire Interuniversitaire des Systèmes atmosphériques, LISA, Uni
versités Paris 12 et Paris 7 et
CNRS, 61 av.
Général de Gaulle, 94010 Créteil,
France




This talk is concerned with the con
tributions of high resolution spectroscopy to the study of
small molecules of biological interest. A knowledge of the properties of “elementary blocks” or
“biomimetic molecules” (such as amino acids, peptides, nucleic acids, sugars etc…) can indeed
allow t
o improve the prediction of the structure and the function of larger biomolecules. Many
of the molecules of interest for biology present one (or more) large amplitude internal rotation
motion(s) due to a methyl CH
3

group. Fourier transform microwave spectr
oscopy in the gas
phase coupled with high level quantum chemical calculations has recently led to the precise and
detailed determination of molecular structures, dipole and quadrupole moments, and potential
barriers for the lowest energy conformers of a nu
mber of molecules. In this talk, we will show
results from different molecules which can be considered as prototypes of the peptide bonding,
namely:
the
ethyl acetamidoacetate
molecule
CH
3
-
CH
2
-
O
-
C(=O)
-
CH
2
-
NH
-
C(=O)
-
CH
3

(1,2),

the

N
-
acetyl alanine methyl est
er molecule
CH
3
C(=O)NHCH(CH
3
)C(=O)OCH
3

(3)

and
the
methyl carbamate
molecule
H
2
NC(O)OCH
3

(4,5).

We will also show preliminary results for the
study of a two
-
top internal rotor, the methyl acetate molecule

CH
3
-
O
-
C(=O)
-
CH
3
, for which

a
new program has been
written.



R
eferences:


(1)
R. J. Lavrich, A. R. Hight Walker, D. F. Plusquellic, I. Kleiner, R. D. Suenram, J. T.
Hougen and G. T. Fraser, Chem. Phys.
.
119
, 5497 (2003
).

(2)

I. Kleiner and J. T. Hougen, J. Chem.
Phys.,
119
, 5505 (2003).

(3)

D. J. Plusque
llic, I. Kleiner, J. Demaison, R. D. Suenram, R. J. Lavrich, F. J. Lovas, G. T.
Fraser and V. V. Ilyushin, J. Chem. Phys,
125
, 104312 (2006).

(4) J. Demaison, A. G. Csaszar, I. Kleiner, H. M
ø
llendal, J. Phys. Chem.A.,
111
, 2574 (2007).

(5) V. Ilyushin, E.
Alekseev, J. Demaison and I. Kleiner, J. Mol. Spectros.,
240
, 127 (2006).