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Photochemical formation of organic compounds from mixtures of simple gases simulating the primitive atmosphere of the earth
BioSystems 6 (1975) 229-233 0 North-Holland Publishing Company,
Amsterdam
- Printed in The Netherlands
WILHELM GROTH
Institute for Physical Chemistry ‘l%e Uniuersity of Bonn, Bonn, Germany
been strengthened by many aut ears. First of all, the as
d into
was, aftek
ears as a c
cmtkr
OlQ c*
.”
‘-
tochemical dissociation of carbon dioxide and water vapour [lo]. The following reactions occur: co+0
(1)
HzO+hv-+OH+H
(2)
U&+hv+
Later, it had been shown [11,123 that H atoms react with CO to give formaldehyde or glyoxal according to (31
by various laboratory experiments. S.L. Miller [13], as well as K. Heyns et al. 1141, exposed a mixture of methane, ammonia, water vapour, and hydrogen to an electric spark discharge. From these experiments they obtained several amino acids, carboxylic acids, amines, and other organic compounds. Electric discharges were probably not the urce of ener would form ions and radic tration near the Earth’s surface. As emphasized by tlrey a er part of the ener ravioIet radiati~
2
If mixtures of carbon dioxide and water vapour are illuminated by the xenon lamp, these reactions occur simultaneously. From the primarily formed CO and the dissociation products of water vapour, aldehydes are formeteeted by Schryver‘s ree sation products agent. Their co tate as a layer on the window of the la This prccess is assumed to have played an important role in the Earth’s atmosphere. Under the influence of the Sun’s radiation, oxygen an.d carbon compounds can be formed from water and carbon dioxide. It would give an explanation for the first appearance of free oxygen in the primitive at osphere and for ~matio~ of certain carbon compounds ere probably the prerequisite for the
For this reason, the earlier ~hoto~be experiments were resumed in 1957 [2] mixtures of methane or and water vapour in well as direct photolysi
W and
1296 A, and
of
carried out in a cireul n efficiency
merits
were
of 3 X
analyze y
a paper chro
231 Mercury lamp
TABLE
2
Amounts
3 5 -liter
of amino and fatty acids (in pmoles).
flask
Experiment
No.
2 32.0 23.0 0.5
GIgr&le
ar-Alanine &Aminobutyric
3
acid
Total
55.5
Formic acid Acetic acid Propionic acid otal
4 24.5 12.0 0.2
-
3.67
72 203 17
82 234 15
58 136 9
292
331
203
-
_-____ ixt
as
---
__
3 4 6
+ +
-
_g
-
Q
+
+
-
+ __
+ c
e c
-
-
+ *
232
amino acids could be expected even under the most favorable conditions. The chromatograms of the full runs of ap proxjmateiy 30 hrs, at a temperature of 55” C corresponding to a pressure of water vapour of about 120 torr with mixtures of 400 torr methane and 200 torr ammonia, showed several spots. One of them was definitely d.etermined to be glycine; another spot could be attributed to cr-alanine. The chromatograms of the blank tests did not show any spots. That no reaction products are obtained in the mercury-sensitizing experiments with mixtures of methane, ammonia, and water vapour can be understood by comparing the cross sections of these gases for quenching the Hg resonance wave lengths. The values 3.0 X of ammonia and 1.0 X 10-l e of water are 50 and 20 times greater, respeczively, than the value 0.06 X l(lfl6 cm2 oE methane [IS] b Therefore the excited mercury atoms react neariy exclusively with the former two gases, and only H-atoms, OH-, occur as photochemiNW2-, and cal primary the other hand, methane is not attacked by radicals and H-atoms up to a temperature of 300” C [ 191, The quenching cross section of ethane (0.11 X hO--“” cm2 ) is not much greater than that of methane. Thus the quenching reaction with ethane yields only a small contribution to its dissociation. Ethyl and methyl radicals, however, are pr ably formed by the reactive of ethane with atoms arising from the ph: 8~~~ysis of ammonia and water vapour:
direct photolysis. The quantum energy available from the mercury lamp is not sufficient to dissociate ethane and water vapour directly [20,21] . Therefore, reaction products were obtained from the runs using ethane and water vapour only if mercury sensitizer was present. Under irradiation with xenon resonance wave lengths, the following primary reactions occur in mixt s of methane, ammonia, an water vapour:
Cl&
f hv
,CM, +
Considering the light intensities and the absorption coefficients at the wave ien 1469 A and 1 A, it is reasonable th radicals and H- ms are ternary. for a comparable rate. As a find product, glycine coul nitely determined, but even
[22] in 1959, who meth~e, ammonias nova and Side-
233
only one-half percent of methane had been converted into organic compounds. Therefore, more powerful sources for radiation in the extreme ultraviolet are necessary to produce experimentally higher effects on simulated primitive atmospheres and to determine quantum yields for the production of amino acids by ultraviolet light.
1. Groth, W., and H. Suess, Naturwissens~haften 26, 77 (1938). 2. Groth, W., and H. v. Weyssenhoff, Naturwissen-
8. Unsold, A., “Physik d. Sternatmosphliren,” Berlin, 1937. 9. Groth, W., 2. Elektrochem. 42, 533 (1936). 10. Groth, W., 2. Phys. Chem. B37,307 (1937). 11. Frankenburger, W., 2. Elektrochem. 36, 757 (1937). 12. Groth, W., Z. Phys. Chem. B37, 315 (1937). 13. Miller, S.L., Science 117, 528 (1953); ibid., J. Am. Chem. Sot. 77, 2351 (1955); ibid., Ann. N.Y. Acad. Sci. 69, 260 (1957); ibid., Biochim. Biophys. Acta 23, 480 (1957). 14. Heyns, K., W. Walter, and E. Meyer, Naturwissenscbaften 44, 385 (1957). . Heyns, and K. Pave& 2. Naturforsch. 126. 97 (1954). 15. iller, S.L., and H.C. Urey, Science 130, 245 (1959). 16. Moore, S., and W.H. Stein, J. 893 (1954). 17. Bulen, W.A., J.E. Varner, and B.C. Sot. 52, 3852 (1930). onhoeffer, and J.H. Geib, 2. Al 39, 64 (1928); ibid., A170, 1
e Origin of Life,”
Macmillan,
Phys. Chem. (1934). 20. I&went, ., J. Chem. Pbys. 18, 1532 (1950). 21. Senftleben, pi., and J. Rehren, Z. Phys. 6hem.
rigin of Life on the eds. ), Pergamon, London, 1959. 23.
Q~~~~V~,
iofizika
6,
149 (1961). peruma, C., and 9. Flares, Abstr. 152n eeting Amer. Che . Sot., New Yor (1~~6~,
Amsterdam
- Printed in The Netherlands
WILHELM GROTH
Institute for Physical Chemistry ‘l%e Uniuersity of Bonn, Bonn, Germany
been strengthened by many aut ears. First of all, the as
d into
was, aftek
ears as a c
cmtkr
OlQ c*
.”
‘-
tochemical dissociation of carbon dioxide and water vapour [lo]. The following reactions occur: co+0
(1)
HzO+hv-+OH+H
(2)
U&+hv+
Later, it had been shown [11,123 that H atoms react with CO to give formaldehyde or glyoxal according to (31
by various laboratory experiments. S.L. Miller [13], as well as K. Heyns et al. 1141, exposed a mixture of methane, ammonia, water vapour, and hydrogen to an electric spark discharge. From these experiments they obtained several amino acids, carboxylic acids, amines, and other organic compounds. Electric discharges were probably not the urce of ener would form ions and radic tration near the Earth’s surface. As emphasized by tlrey a er part of the ener ravioIet radiati~
2
If mixtures of carbon dioxide and water vapour are illuminated by the xenon lamp, these reactions occur simultaneously. From the primarily formed CO and the dissociation products of water vapour, aldehydes are formeteeted by Schryver‘s ree sation products agent. Their co tate as a layer on the window of the la This prccess is assumed to have played an important role in the Earth’s atmosphere. Under the influence of the Sun’s radiation, oxygen an.d carbon compounds can be formed from water and carbon dioxide. It would give an explanation for the first appearance of free oxygen in the primitive at osphere and for ~matio~ of certain carbon compounds ere probably the prerequisite for the
For this reason, the earlier ~hoto~be experiments were resumed in 1957 [2] mixtures of methane or and water vapour in well as direct photolysi
W and
1296 A, and
of
carried out in a cireul n efficiency
merits
were
of 3 X
analyze y
a paper chro
231 Mercury lamp
TABLE
2
Amounts
3 5 -liter
of amino and fatty acids (in pmoles).
flask
Experiment
No.
2 32.0 23.0 0.5
GIgr&le
ar-Alanine &Aminobutyric
3
acid
Total
55.5
Formic acid Acetic acid Propionic acid otal
4 24.5 12.0 0.2
-
3.67
72 203 17
82 234 15
58 136 9
292
331
203
-
_-____ ixt
as
---
__
3 4 6
+ +
-
_g
-
Q
+
+
-
+ __
+ c
e c
-
-
+ *
232
amino acids could be expected even under the most favorable conditions. The chromatograms of the full runs of ap proxjmateiy 30 hrs, at a temperature of 55” C corresponding to a pressure of water vapour of about 120 torr with mixtures of 400 torr methane and 200 torr ammonia, showed several spots. One of them was definitely d.etermined to be glycine; another spot could be attributed to cr-alanine. The chromatograms of the blank tests did not show any spots. That no reaction products are obtained in the mercury-sensitizing experiments with mixtures of methane, ammonia, and water vapour can be understood by comparing the cross sections of these gases for quenching the Hg resonance wave lengths. The values 3.0 X of ammonia and 1.0 X 10-l e of water are 50 and 20 times greater, respeczively, than the value 0.06 X l(lfl6 cm2 oE methane [IS] b Therefore the excited mercury atoms react neariy exclusively with the former two gases, and only H-atoms, OH-, occur as photochemiNW2-, and cal primary the other hand, methane is not attacked by radicals and H-atoms up to a temperature of 300” C [ 191, The quenching cross section of ethane (0.11 X hO--“” cm2 ) is not much greater than that of methane. Thus the quenching reaction with ethane yields only a small contribution to its dissociation. Ethyl and methyl radicals, however, are pr ably formed by the reactive of ethane with atoms arising from the ph: 8~~~ysis of ammonia and water vapour:
direct photolysis. The quantum energy available from the mercury lamp is not sufficient to dissociate ethane and water vapour directly [20,21] . Therefore, reaction products were obtained from the runs using ethane and water vapour only if mercury sensitizer was present. Under irradiation with xenon resonance wave lengths, the following primary reactions occur in mixt s of methane, ammonia, an water vapour:
Cl&
f hv
,CM, +
Considering the light intensities and the absorption coefficients at the wave ien 1469 A and 1 A, it is reasonable th radicals and H- ms are ternary. for a comparable rate. As a find product, glycine coul nitely determined, but even
[22] in 1959, who meth~e, ammonias nova and Side-
233
only one-half percent of methane had been converted into organic compounds. Therefore, more powerful sources for radiation in the extreme ultraviolet are necessary to produce experimentally higher effects on simulated primitive atmospheres and to determine quantum yields for the production of amino acids by ultraviolet light.
1. Groth, W., and H. Suess, Naturwissens~haften 26, 77 (1938). 2. Groth, W., and H. v. Weyssenhoff, Naturwissen-
8. Unsold, A., “Physik d. Sternatmosphliren,” Berlin, 1937. 9. Groth, W., 2. Elektrochem. 42, 533 (1936). 10. Groth, W., 2. Phys. Chem. B37,307 (1937). 11. Frankenburger, W., 2. Elektrochem. 36, 757 (1937). 12. Groth, W., Z. Phys. Chem. B37, 315 (1937). 13. Miller, S.L., Science 117, 528 (1953); ibid., J. Am. Chem. Sot. 77, 2351 (1955); ibid., Ann. N.Y. Acad. Sci. 69, 260 (1957); ibid., Biochim. Biophys. Acta 23, 480 (1957). 14. Heyns, K., W. Walter, and E. Meyer, Naturwissenscbaften 44, 385 (1957). . Heyns, and K. Pave& 2. Naturforsch. 126. 97 (1954). 15. iller, S.L., and H.C. Urey, Science 130, 245 (1959). 16. Moore, S., and W.H. Stein, J. 893 (1954). 17. Bulen, W.A., J.E. Varner, and B.C. Sot. 52, 3852 (1930). onhoeffer, and J.H. Geib, 2. Al 39, 64 (1928); ibid., A170, 1
e Origin of Life,”
Macmillan,
Phys. Chem. (1934). 20. I&went, ., J. Chem. Pbys. 18, 1532 (1950). 21. Senftleben, pi., and J. Rehren, Z. Phys. 6hem.
rigin of Life on the eds. ), Pergamon, London, 1959. 23.
Q~~~~V~,
iofizika
6,
149 (1961). peruma, C., and 9. Flares, Abstr. 152n eeting Amer. Che . Sot., New Yor (1~~6~,