Download (4Mb) - Etheses - Saurashtra University

Chapter III CHN Analysis, FT IR …..
Frequency
(cm -1 )
3615
3350
Table: 3.3 FT-IR assignments of pure and 0.3 wt % various amino acids doped
KDP
Pure KDP +
L-histidine
crystals.
Absorptions in wave numbers
KDP+
L-threonine
The absorption around 2380 cm -1 due to N-H symmetric stretching
vibration is absent in Pure KDP crystals. Similarly, the absorptions around
1715 cm -1 due to C=O stretching is not present in pure KDP crystals. These
two assignments are exclusively related to presence of amino acids in KDP
crystals. While, the absorptions around 1600 cm -1 , 1350 cm -1 , 1100 cm -1 , 975
cm -1 and 530 cm -1 are due to O=P-OH symmetric stretching, P=O, O-P-OH
symmetric stretching, O=P-OH bending and P-OH deformation vibrations.
141
KDP+
DL-methionine
3580 3445 3440 3481.7
2380 2343.4 2338 2394.7
2250 2320 2285.7
Assignments
Free O – H
Stretching
N – H asymmetric
stretching
N – H symmetric
stretching
P – O – H
asymmetric
stretching
1715 1750 1727 1755.4 C = O stretching
1600 1656 1659 1615 1602
1350 1305.5 1302 1302 1294.2
1100 1108.3 1097.4 1098 1079.2
975 889.3 910.3 911 990.5,938.4
O = P – OH
symmetric
stretching
P = O symmetric
stretching
O - P – OH
symmetric
stretching/
C-S-C
O = P – OH
bending
530 538.4 536.2 536 564 P–OH deformation