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925
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11
ORNL
UNCLASSIFIED





ORNL-p-925
...
TIE-
MASTER
FEB 11 iOL
DIVISION OF PHYSICAL CHEMISTRY
Abstract of a paper to be presented at Detroit, Michigan, April 4-9, 1965
Papers for the program should reach the Chairman-Elect not later than Dec. 29, 1964. No papers can be accepted,
changed or withdrawn after that date. Mail this short abstract, with three carbon copies on plain white paper, and the
long abstract or manuscript to....
CDi F-65040-2
R.B. Bernstein, Department of Chemistry, University of Wisconsin, Madison, Wisconsin.
Where (wo or more papers are submitted from one research group an order of priority must be given.
TITLE OF PAPER The Absorption Spectrum of H20 and Dg0 in the Near Infrared Region as a
Function of Temperature froid -20° to 250°C. *
AUTHORS
Complete Mail Address
ACS Division
American Chemist or Chemi-
(list address only
Member?
(underline nüme of speaker)
Member?
cal Engineer? (il rot, give
once iſ all authors
classification such as
at same address)
biologist, physicist, etc.)
W. C. Waggener
Chemistry Division
Yes
Yes
Chemist
Oak Ridge National
Laboratory
Post Office Box X
Oak Ridge, Tennessee
A. J. Weinberger
Yes
No
Chemist
R. W. Stoughton
Yes
Yes
Chemist
Work done at
ABSTRACT. Length 200 words. Please type double spaced within the ruled area. If you need more space for 200 words,
or more space for special abstracts, please continue giour abstract on a second, plain sheet.
We are studying the spectra of water in the condensed states between 0.7 and 2.0 H
and have measured the temperature dependences of the broad (2 v, + Vz) and (v1 + va + V3
absorption bands of Ho and D20 in ice to 20° below the freezing point, in the super-
cooled liquid to 150 below the freezing point, and in the liquid from the freezing point
to 250°C and ca. 39 atm. At 250°C we have observed the additional bands, (v + Vz),
(2 va + V3) and (va + vz), în saturated and superheated 120 steam.
The spectra of H20 and D20 are qualitatively similar; however, the D20 bands occur
at longer wavelengths by a factor of 1.35, are broader, more complex, less intense, and

H20 in the D20 used.
The observed frequency shifts of both the (2 v1 + vz) and (vz + V2 + v3) bands in
the following condensed phases from the frequencies of these bands in the dilute gas
(literature values) are about -1.7% for liquid at 250°C; -2.1% for liquid at 100°C; -5.194
for liquid at 0°C; -5.9% for liquid at -15°; -8.4% for ice at 0°; and -9% for ice at
-20°. This environmental sensitivity of water spectra, attributed primarily to inter-
molecular H-bonding, is 25 to 30 times that observed for similar near infrared spectra
com, in which van der Waals forces appear to govern the bulk properties.
*Research sponsored by the U. S. Atomic Energy Commission under contract with the Union
Carbice Corporation.
Long Abstract
The Absorption Spectrum of H20 and D20 in the Near Infrared
Region as a Function of Temperature from -20° to 250°C
W
C. Waggener, A. J. Weinberger and R. W. Stoughton
Chemistry Division, Oak Ridge National Laboratory
Oak Ridge, Tennessee
Introduction
In an initial exploratory study of the effects of temperature upon the near
infrared bands of liquid C6H14, NH3, H20 and D20 in the region of the third har-
monic or the CH, NH, OH, and OD stretching modes we observed that these relatively
broad, complex bands differ markedly from one another. Recently, we have measured
the spectrum of co, from below its freezing point to above its critical point in
order to compare the temperature sensitivities of the above liquids in which spe-
cific interactions such as H-bonding are a factor with a liquid in which van der
Waals forces alone appear to govern the bulk properties. We are presently
(1) W. C. Waggener, A. J. Weinberger and R. W. Stoughton, Paper 21, Div. of Phys.
Chem., National ACS Meeting, Chicago, Sept. 1964.
studying the spectra of water between 0.7 and 2.0 u in considerable detail, and
over a much wider temperature and phase range than other recent investigations»)17.
(2) Yamatera, Fitzpatrick and Gordon, J. Mol. Spectry., 14, 268 (1964).
(3) Buijs and Choppin, J. Chem. Phys., 39, 2035 (1963).
(4) Luck, Ber. der Bunsengesellschaft., 67, 186 (1963).
Our immediate purpose is to correlate the observed changes in the position, shape
and intensity of these extremely complex spectra with the environmental factors
responsible for them. We hope that this type of data eventually will provide a
Research sponsored by the U. S. Atomic Energy Commission under contract with
the Union Carbide Corporation.
bridge between the well-understood vibration-rotation spectrum of water vapor at
room temperature and the still speculative vibrational band systems in the con-
densed states.
Experimental Apparatus
The absorption data were taken with a standard Cary Model 14M recording
spectrophotometer equipped with a redesigned version of the special equipment
previously described'.
(5) W. C. Waggener, Rev. Sci. Instr., 30, 788 (1959).
Both the sample cell ani. the reference cell are designed to permit gas-liquid
equilibration and have identical systems for temperature and pressure from below
-80° to 280°C and 0 to 2000 psia.
The titanium absorption cell bodies are modified to incorporate a reservoir
space above the cylindrical cell space of the original design (see Figure 1).
.
.
re 1).
The heater-cooler, in the form of a cylindrical annulus which surrounds each
cell body, is fabricated with a cooling channel and a resistance heater winding
both embedded in a matrix of pure copper. This assembly is "canned" in a gold-
plated thermal radiation sheath and is cradle-mounted as in the earlier equipment.
Helium, cooled with liquid nitrogen, is used as the cooling fluid.
The temperatures of the sample and reference cells are controlled above and
below room temperature by modulation of heating and cooling supplies respectively.
Temperature control is better than I 0.1°C, and is achieved by sensing a thermo-
couple located in either cell or heater-cooler body. A Leeds and Northrup millivolt
recorder with a stable millivolt suppression supply and a Leeds and Northrup
duration-að.just type of controller are used for each cell.
The cell windows and the contents of either absorption cell may be examined
visually for bubbles and turbidity by inserting a special borescope into one of
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the aligrment sleeves installed in the phototube compartment. The visible source
beam of the spectrophotometer provides 11).umination of selectable color and
intensity.
Experimental Procedure
Spectral measurements were made with 3.81 cm. cells using CC1, at 25°C in
the reference cell. Specially purified water samples were introduced into the
bottom of the evacuated sample cell by means of a gas-tight Hamilton syringe.
The remaining dissolved air was removed by vacuum pumping the vapor phase.
The liquid level was adjusted above the optical path during filling, and
the position of the meniscus was followed with the aid of the borescupe during
operation of the cell.
Measurements of saturated and superheated vapor at 250° were made after
carefully drawing off the liquid phase from the bottom of the cell.
Spectroscopic Measurements
Our procedure for measuring the spectrum of a sample as a function of
temperature and pressure involves adjusting the sample to hect or cool slowly
enough so that the data taken are independent of the rate of temperature change.
The chart drives for the spectrophotometer and temperature recorders are synchro-
.
nized with the clock and the spectral range of interest is scanned repetitively.
..
Wavelengths are recorded timewise with a fiducial mark at 100 A or 1000 A inter-
.. ..
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vals. It is then a simple matter to correlate the spectral record with temperature
.
.
..
and plot any parameters as a function of temperature.
.....
mura
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.
The above method minimizes the time and effort required for data-taking while
.
optimizing the precision of the measured or related parameters.
.
-aaw**
2.5
Laboratory distilled HO was put through an all-quartz double distillation
apparatus prior to use. Commercial D2O (99.8 mo1%) was purified with respect to
a trace of organic material by distillation from acid KyCr207, alkaline KMnO4
and an empty quartz flask in successive stages.
-ngo,
h e
T
The data for water were obtained in experiments run at 0.2 - 0.3°/min. There
was no discernible difference in the fit of data obtained by alternate heating
and cooling cycles over the same temperature range. In these experiments the
scanning speed was 10 A/sec. with a chart display of 300 A/in.
An aspect of the versatility of our cell assembly is the ability to freeze
a sample in situ and examine the corresponding spectrum of the solid. Samples
-
-
were carefully frozen over periods of 1 to 2 hours, the process being followed
either visually with the borescope or spectrophotometrically using dispersed
radiation (0.589 ) through the sample.
The light loss due to scattering in a sample at the freezing point was large
but uniform (90-95%) over the region of interest (0.7 - 2.0 u) and nearly con-
stant with time, the established baseline rising less than 0.001 of an absorbance
.
-
-
-
unit per minute under stress of the heating effect of the undispersed radiation
from the infrared source lamp.
Results and Discussion
The two families of curves in Figure 2 permit a direct comparison of the
effect of temperature on the suctra of liquid H,O and D,O under saturation pres-
sures from near the freezing point to 250°C. The spectra are qualitatively
similar; however the D20 bands occur at longer wavelengths by a factor of 1.35,
are broader, more complex, less intense, and generally less temperature sensi-
tive. The additional breadth and complexity of the Dgo bands is attributed, at
least in part, to the presence of light water contaminant.
The (3 v3) bands at 0.85 and 1.12 u are clearly visible in Figure 1 but are
of low intensity. However the (2 v + v) and (v + v + v) bands were amenable
to close scrutiny. All bands tend to increase in intensity and shift toward
lower wavelength (higher energy) with increasing temperature. The (vy + V2 + Vz)
22
7.
IT
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hely
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bands, in particular, exhibit two prominent components which are involved in the
large frequency shifts near the freezing points.
Figure 3 presents the results of a study of the temperature deper.dence of
the position of maximum absorption of the (vz + V2 + V3) band ir. liquid water.
These data reveal clearly the presence of the two components. The low frequency
component, most intense at the freezing point and below", decreases with rising
teriperature while the high frequency component of the band is becoming prominent.
-:-
E
Both components are partially resolved into two peaks or equal intensity at 43°C.
Figure 4 shows a similar study of the higher energy (2 V2 + vz) bands. While
the separation of components is less apparent, nevertheless, the similarities in
the behavior of dv/dt with T from - 159 to 250° for the bands are striking.
The liquid state spectra become less broad and complex as the temperature
rises to 250° (see Figure 2). Figure 5 is a graph of the temperature dependence
of the (2 V1 + Vz) band widths. The breadths of these bands at the freezing
point are a factor of 80 to ico greater than similar infrared bands in liquid con.
Also, these bands narrow rather than broaden with increasing temperature, an indi-
cation that the effect of H-bonding is over-riding the kinetic broadening which
must occur in the absence of specific interaction.
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The temperature dependence of the molar absorptivity of the (2 vn + Vz) band
maxima of liquid water (see Figure 6) is linear and anounts to +0.6%/°C at the
freezing point.
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1.1.'....
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amistin
Figure 7 shows the pressure dependence of H,O vapor spectrum at 250°C. The
uppermost curve is that of saturated stean at 250° and 39.9 atm. The (2 v7 + V3)
and (vz + va + vz) bands are clearly visible but of low intensity as the vapor
density is 1/40 that of the liquid. A comparison of the molar absorptivities of
the band maxima with the corresponding liquid spectra indicates that intensities
of these bands are quenched a factor of 30 to 35 in the more condensed phase.
"In addition to the results shown in the figures, data have been obtained below
the normal freezing points and for ice.
-6-
The (2 v2 + vz) and (v2 + vz) bands which were a factor of 40 too intense
for study in the liquid phase show, at 3.4 atmospheres, the rotational fine
structure which characterize these bands in the dilute gas state. The contours
of the three sub-bands persist in each case up to the saturation pressure.
We are continuirg to analyze these data at present and plan to extend this
study to include measurements at 300° anü with shorter cells.
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438
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UNCLASSIFIED
ORNL- LR-OWG. 318418

CELL-AND- RESERVOIR CAVITY
al.
TEFLON
SEAL
RING
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btii.
IA
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SAPPHIRE
WINDOW
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'LIQUID LEVEL
PIPING CONNECTION
METAL CORE
CENTER LINE OF LIGHT BEAM
Figure
! SCHEMATIC' DESIGN OF THE COMBINED CELL-AND RESERVOIR CAVITY OF
THE HIGH TEMPERATURE - PRESSURE SPECTROPHOTOMETRIC CELL
UNCLASSIFIED
ORNL-DWG. 64.8-413

TTTTT
(111)
HO
ATM
39.2
16.6
250
204
159
116
70
5.9
1.22
0.3 -
-
:::
ABSORBANCE (3.81 CM CELL)
1201)
0,0 (99.8 MOL %)
°C ATM (114)
250 39.4-
204 | 16.6
160 6.0-
116 1.7
71 0.3
27
| 0.0
(201)
(003)
1003)
III ILI
.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.
WAVELENGTH (MICRONS )
TEMPERATURE DEPENDENCE OF THE ABSORPTION
SPECTRUM OF LIQUID WATER UNDER SATURATION PRESSURI
FROM NEAR THE FREEZING POINT TO 250°C. REFERENCE
CELL CONTAINED CCIA (LIQ. 25°C, 1 ATM ).
Figure 2.
UNCLASSIFIED
ORNL-DWG. 64-8607
8700 TTTTTTTTTT

46550
8650
som
er godt
|_0.227 + 0.005 cm,
:
6500
8600
tagirone
6450
8550
S
endaleanselemarked
6400
| 0.216 + 0.004 cm/°C
Vmax (cm') H2O
Vmax (cm-) D20
тттттті
-6300
84004
6250
ooroorsaang sobom ooooo
8350
34 cm /ac
+6200
-
43° C
OSSOVER TEMPERATURE
8300
TitleLIIIII6450
Ö 40 80 120 160 200 2400100
TEMPERATURE (°C)
Temperature Dependence of the Position of
Maximum Absorption of the (v + Vz+V3) Band in Liquid
Water: • H20 ;•D20 (99.8 mol %).
Figure 3. a
UNCLASSIFIED
ORNL-DWG. 64-8606
10,4505TTTTTTTTT

10,4006
10,350 -0.313.
-7750
) H2O
v 10,300
00.283 4 0.008 cm/Cumbernalelo
Vmax (cm
East .co com o 8o 8o 8 000 89000 8°.
Vmax (cm-') D20
I 5.2 cm /°C
TONTT
10,200
7600
10,150
A
7550
20
10,100
40
IIIIIIIIIIII7500
20 80 120 160 200 240
TEMPERATURE (°C)
Temperature Dependence of the Position of Maximum
Absorption of the (20, +Vz ) Band in Liquid Water :
• H2O ; • D20 (99.8 moi %).
Figure 4.
UNCLASSIFIED
ORNL-DWG. 64-8994
-TT

800
600F
Awa(cm-4)
400
400+
2000
40
80
_
120
1
160
200
240
Temperature Dependence of the (207+ V3) Bandwidth in
Liquid Water : o H20; D20 ( 99.8 mol %).
Figure 5.
.
UNCLASSIFIED
ORNL-DWG. 64-8993
T
O
RNI DWG. 68 9993

Emax (liter mol-'cm') x 103
W 25-
HO
B
120
160
200
240
Occordio
°C
Temperature Dependence of the Molar Absorptivity of the
.cz
(99.8 mol %).
.......
Figure 6.
a
UNCLASSIFIED
ORNL-DWG. 64-8555
RESOLUTION (Å)

(011)
NOTE:
VIBRATIONAL QUANTUM
NOS. Vivre. FOR THE UPPER STATE
OF EACH COMBINATION BAND ARE
IN BRACKETS: THE LOWER STATE
IS (000), FOLLOWING MECKE.
J. PHYSIK 81, 313 (1933).
39.9 ATM--
M
-36 Å
(101)
21.8 ATM
ABSORBANCE (381 CM CELL)
14
14 Å
to
ē.
- 4ått
H-58
(111)
(201)
W
41021) 3.4 ATM
0.06ee suhe
23
8
DO
1.4 1.6 1.8
2.2 2.4
WAVELENGTH (MICRONS).
PRESSURE DEPENDENCE OF THE ABSORPTION SPECTRUM OF WATER VAPOR AT 250°C.
REFERENCE CELL CONTAINED CCIA (LIQ., 25°C, 1 ATM.).
Figure 7.
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DATE FILMED
4/ 7 /65







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-LEGAL NOTICE

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.,:
M
indra,
This roport was prepared as an account of Government sponsored work. Neither the United
Statos, nor the Commission, nor any person acting on behalf of the Commission:
A. Makes any warranty or representation, expressed or implied, with respect to the accu-
racy, complotonosu, or unofulnoss of the information containod in this report, or that the use
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B. Assumos uny liabilities with respect to the use of, or for damayes resulting from the
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As used in the abovo, "person acting on behalf of the Commission” includes any em-
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disseminates, or provides access to, any information pursuant to his employment or contract
with the Commission, or his employment with ouch contractor.
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