7 Biologically Relevant Molecules Studied in Low Temperature Inert Matrices
185
O
O
H
N
H
H
H H
O
O
N
H
H
H
H
H
O
O
N
H
H
H H
H
I
I I
I II
Fig. 7.4 – the lowest energy conformers of non-ionic glycine, I, II and III
1000
1800
1600
1400
1200
1000
800
6 00
0.5
0.6
0.7
0.8
0.9
1.0
1800
1600
1400
1200
1000
800
6 00
0.5
0.6
0.7
0.8
1800
1600
1400
1200
1000
800
6 00
b
Absorbance
Absorbance
Relative intensities
Annealing 200 K
Wavenumber / cm
-1
*
Annealing 85 K
a
KBr pellet
(room temperature)
After deposition 9 K
δNH
δCH 3 s
δCH 2
twCH 2
ωCH 2
γCO
γNH
νC(H3)N
c
Calculated spectrum of the neutral dimer
γCH 2
νCN
νCC
δCCO
δOCO
τCO
CO+ COH
δCOH+νCO
νC=O
Fig. 7.3 a Rom temperature IR spectrum of crystalline sarcosine in a KBr pellet; b annealing
experiments carried out on the sarcosine low temperature solid film; c dFt(B3LYP)/6-311++g**
calculated IR spectrum of the centrosymmetric carboxylic acid dimer of non-ionic sarcosine, with
monomeric units in their most stable conformation [23]. (Reproduced from [21] with permission
from the PCCP owner Societies)