A TABLE OF QUANTUM YIELDS I N EXPERIMENTAL PHOTOCHEMISTRY1
FARRINGTON DANIELS Department o j Chemistry, University of Wisconsin, Madison, Wisconsin Received M a y 66, 1058
I n the early development of quantitative photochemistry it was believed by some that the Einstein relation would apply in many cases not only to the primary process of photoexcitations but to the overall reaction as well. Quantum yields were summarized with the purpose of testing this hypothesis. Any hope of simplicity in chemical kinetics disappeared long ago, and the present table has been assembled not to emphasize the almost universal occurrence of secondary effects which follow the primary process of quantum absorption, but to record the experimental facts of photochemistry in the simplest possible manner. The primary excitation is usually followed by rearrangements and degradation of the energy as heat, by reverse or competing reactions which make the overall quantum yield less than unity, or by continuing reactions which produce a chain and give a value greater than unity. Sometimes it is possible to study these factors from the magnitude of the quantum yield and its response to influences such as temperature, wave length, concentration, and chemical reagents. The amount of chemical reaction produced by the absorption of radiation will change with the duration of exposure, the intensity of the light, the thickness and condition of the absorbing material, and other factors. The fundamental simple relation between light and chemical action, however, is the quantum yield @, Le., the number of molecules of substance reacting for each quantum of radiation, or photon, absorbed. When this is known the extent of the chemical reaction produced by the absorption of a given amount of light is easily calculated. In table 1 are summarized the findings of most of the quantitative photochemical researches in which the results are expressed in terms of quantum yields. Many excellent researches are not included, simply because the results were not given in these terms. Photochemistry has been greatly stimulated by hypotheses in chemical kinetics, and the testing of these hypotheses has been the chief aim in many cases. For Contribution No. 2 to the Third Report of the Committee on Photoohemistry. National Research Council.
713
FARRIXGTOh7 DAKIELS
t
QUANTUM YIELDS IN EXPERIMENTAL PHOTOCHEMISTRY
71 5
FARRINGTON DANIELS
e I
3 h
c
9 U
UUAN 1U
h
OD
E
M
ILLLlJb IN
BCIXY'LfllMBN lAL YHUIULHBMISTXY
718
FARRINGTON DANIELS
-
h
2
N w.
v
v
N u3
3
a
a
$
3
a
3
c3
d
d
35
u::
719
QUANTUM YIELDS IN EXPERIMENTAL PHOTOCHEMISTRY
0
8 I
%
82
W 3 u 3
3 m 3
%
N m
W
3
m 0
ri
a 0 N
e4
6
8
B 8 RR
88
720
FARRINGTON DANIELS
-2
N v)
0
0 ( v) 3
3
m
h
l a "
d
d
b
721
QIXNTCM YIELDS IN EXPERIMENTAL PHOTOCHEMISTRY
c
v
h
m
E!
v
a
3
h * h
8
013 v v
h N
x
0
3
3 4
x 0
8
x
ztd
x"
722
FARRIKGTOK DANIELS
QUAKTUM YIELDS IN EXPERIMENTAL PHOTOCHEXISTRY
723
724
FARRINGTON DANIELS
h
h
m
k
0
V
h
h
E?
s
m
v
v
c
h
?
0
m 0 0
n
00s cod
0 0
"V
2
E?
-.?
0
0
725
QUANTUM YIELDS IN EXPERIMENTAL PHOTOCHEMISTRY
3 u 3
m oo 0 0 0
MMu3
v)
0
YOSYYY
0 0 0 0 0
Yo999 0 3 3 0
22
V
v)
3
V
h v) O O
%
A22
cr
0
0
0
0
0
-
h
'9'90 0 0 0
0
-
726
FARRINGTON DANIELS
.-.-"B
8a
-2 %.
C
't
m
I
F
C
wF4
c r g
727
QUANTUM YIELDS IN EXPERIMENTAL PHOTOCHEMISTRY
2 0
728
FARRINGTON DANIELS
s v
iii E E E 0 0 0
0 0 0
- m m
h
229
v
%
N m
Q
s
5:
0
9
u
QNANTUM YIELDS IN EXPERIMENTAL PHOTOCHEMISTRY
729
730
FARRINGTON DANIELS
these purposes it is often unnecessary t o express the results in absolute units (quantum yields). I n many cases the quantum yield varies with temperature, concentration, and intensity. Part'icularly in chain reactions the quantum yield may vary considerably wibh slight changes in the reacting system and with traces of impurities. Special conditione, such as concentration, are given in the last, column of table 1. When the temperature is not given it may usually be taken as room temperature (about ZOOC.). Parentheses around a quant'umyield indicate a lesser degree of accuracy. When there is uncertainty regarding @, the original article should be consulted. The references are given in parentheses in the last column and include references to earlier investigations. REFERESCES (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (34)
AKEROYD AND KORRISH: J. Chem. SOC.1936, 890. ALLMAKD, CUBLIFFE,A X D lf.4DDISON: J. Chem. S O C . 131,655 (1927). .kLLlMABD AXD STYLE:J. Chem. soc. 1930, 596, 606. ANDERSON,CRUMPLER, AND HAXMICK: J. Chem. SOC.1936, 1679. BAUERAND DANIELS:J. Am. Chem. SOC.66, 378, 2014 (1934). J. Am. Chem. SOC.61, 109 (1929). BAXTERANDDICKIBSON: BECKMAN AND DICKITSON: J. Am. Chem. SOC.62, 124 (1930). BENTOXAND CUNNIKGHAM: 3. Am. C,hem. SOC.36, 2227 (1935). BERTHOEDA N D PORRET:Helv. Chim. Acta 17, 237 (1934). BLACET, FIELDING, A N D ROOF:J . ilm. Chem. S O C . 69,2375 (1937). BLACETAND ROOF: J. Am. Chem. 6oc. 68, 73 (1936). BLACET AND ROOF: J. Am. Chem. SOC.68, 278 (1936). J. Chem. SOC.1936, 1638. BLOCHASD XORRIBH: BODENSTEIK AND KISTIAKOWSKY: Z. physik. Chem. 116, 371 (1925). BODENSTEIN . ~ N DLIEXEWEG: Z. physik. Chem. 119, 123 (1926). BODENSTEIX AND L ~ T K E M E Y EZ. R :physik. Chem. 114, 208 (1925); LEWISAND RIDEAL:J. Am. Chem. SOC.48, 2555 (1926). BODENSTEIN A N D WINTER:Sitzber. preuss. rlkad. Wiss., p. 2 (1936). BONHOEFFER: Z. Physik 13, 94 (1923). BOOHERA N D ROLLEFSOK: J. Am. Chem. SOC.66, 2288 (1934). BOOKA N D EGGERT:Z . Elektrochem. 29, 521 (1923). BOWENAND HORTON:J. Chem. 6 O C . 1936, 1685. CARRICO A X D DICKISSOX:J . Am. Chem. Soc. 67, 1343 (1935). CHAPYAS:J. Am. Chem. SOC.67, 416 (1935). COEHNASD CORDES:Z. physik. Chem. B9, 1 (1930). CRAGGS A K D ALLMASD: J. Chem. Soc. 1936, 241. CRIST: J. Am. Chem. Soc. 64,3939 (1932). DAMONABD DANIELS:J. Am. Chern. Soc. 65,2363 (1933). DAVIS,JAHN, AND BURTON: 3. Am. Chem. Soc. 60, 10 (1938). DERIGHTA N D WIIG: J. Am. Chem. Soc. 67, 2411 (1936). DHARA N D BHARGAVA: J.Phys. Chem. 39, 1231 (1935). DICKINSON ASD CARRICO: J. Am. Chem. Soc. 66, 1473 (1934). DICKINSOSAND JEFFREYS:J. Am. Chem. SOC.62, 4288 (1930). DICKIKSON ABD LEERMAKERS: J. Am. Chem. SOC.64, 3852 (1932). DICKINSON A N D RAVITZ:3. Am. Chem. SOC. 62, 4770 (1930).
QUANTUM YIELDS IN EXPERIMENTAL PHOTOCHEMISTRY
731
EGGERTAND BORINSKI:Z. Physik 26, 865 (1925); ELGINAND TAYLOR:J. Am. Chem. SOC.61,2059 (1929). EMELEUS AND JOLLEY:J . Chem. SOC.1936, 1612. FARKAS: Z. physik. Chem. B23, 89 (1933). FARKAS AND HARTECK: 2. physik. Chem. B26,257 (1934). FISKAND NOYES:J. Am. Chem. SOC.68, 1707 (1936). FORBES AND HEIDT: J. Am. Chem. SOC.66, 2407 (1933). FORBES AND HEIDT: J. Am. Chem. SOC. 66, 1671 (1934). FORBES, HEIDT,AND SICKMAN: J . Am. Chem. S O C . 67, 1935,2331 (1935). FRANKENBURGER AND KLINGHARDT: Z . physik. Chem. B16,421 (1932). FUGASSI:J. Am. Chem. SOC.69, 2092 (1937). GHOSHAND BHATTACHARYYA: 2. physik. Chem. B31,420 (1936). GHOSH,BHATTACHARYYA, AND BHATTACHARYYA: 8. physik. Chem. B32, 145 (1936). (48) G H O S HSARAYANMURTI, ~ AND RAY: Z. physik. Chem. B29,236 (1935). (49) GHOSHAND RAY: Z. physik. Chem. B32, 158 (1936). (50) GIBSONAND IREDALE: Trans. Faraday SOC.32,571 (1936). (51) GORINAND TAYLOR:J. Am. Chem. SOC. 66, 2042 (1934). (52) GREGORY AND STYLE:Trans. Faraday SOC. 32, 724 (1936). (53) GROTH:Z. physik. Chem. B38,366 (1937). (54) HARRISAND KANISKY:J. Am. Chem. SOC.67, 1154 (1935). (55) HEIDT: J. Am. Chem. SOC. 64,2840 (1932). (56) HEIDT: J. Am. Chem. Soo. 67, 1710 (1935). (57) HoLhiEs AND DANIELS:J . Am. Chem. Soo. 66, 630 (1934). (58) HOWEAND SOYES: J. Am. Chem. SOC.68, 1404 (1936). (59) IRED.4LE AND STEPHEN: Trans. Faraday SOC. 33, 800 (1937). (60) JOST: Z. physik. Chem. 134,92 (1928). (61) JUNGERS AND TAYLOR:3. Chem. Phys. 3, 338 (1935). (62) KIRKBRIDE A N D NORRISH:J. Chem. SOC. 1933, 119. (63) KISTIAKOWSKY: J. Am. Chem. SOC.49,976 (1927). (64) KISTIAKOWSKY: J. Am. Chem. Soc. 62, 102 (1930). (65) KOBLITZAND SCHUMACHER: z. physik. Chem. B36, 11 (1937). (66) KORNFELD AND WEEGYANN: 2 . Elektrochem. 36, 789 (1930). (67) KRAUSKOPF . ~ N DROLLEFSON: J. Am. Chem. SOC. 68, 443 (1936). (68) KCCHLER . ~ N DPATAT:hlonatsh. 68,275 (1936). (69) LEERMAKERS: J. Am. Chem. SOC.66, 1537 (1934). (70) LEERMAKERS: J. Am. Chem. SOC.66, 1899 (1934). (71) LEIGHTOX A N D B L A C E JT.:Am. Chem. Sac. 66, 1766 (1933). (72) LEIGHTON, W. G., AND FORBES:J. Am. Chem. SOC. 62, 3139 (1930). (73) LEIGHTON AND LUCY:J . Chem. Phys. 2 , 756 (1934). (74) LEIGHTONA N D MORTENSON: J. Am. Chem. SOC.68, 448 (1936). (75) LEIGHTONAND STEINER: J. Am. Chem. SOC.68,1823 (1936). (76) LEWIS: J. Phys. Chem. 32,270 (1928). J . Am. Chem. Sac. 64,94 (1932). (77) LINDA N D LIVINGSTON: (78) LINDA N D LIVIXGSTON: J. Am. Chem. SOC.66, 1036 (1933). (79) LYONSAND DICKINSON:J. A m . Chem. SOC.67,443 (1935). (80) MARSHALL: J. Phys. Chem. 30, 1078 (1926); J. Am. Chem. SOC.64, 4460 (1932). (81) MCDONALD: J . Chem. SOC.1928, 1. (82) MELVILLE:Proc. Roy. SOC.(London) A139, 541 (1933). (83) MEYERSA N D BECKYAN: J. Am. Chem. Soc. 67,89 (1935). (84) MITCHELLAND HINSHELWOOD: Proc. Roy. soc. (London) A169, 32 (1937). (85) LMONTGOMERY AND ROLLEFSON: J . Am. Chem. SOC. 66, 4025 (1933). (35) (36) (37) (38) (39) (40) (41) (42) (43) (44) (45) (46) (47)
732
FARRINGTON DANIELS
(86) M U L L E R A X D SCHUIIACHER: Z. physik. Chem. B36, 285 (1937). (87) NEWLING,STAVELY, .4XD ~IOELWYN-HVGHES: Trans. Faraday Soc. 29, 1155 (1933). (88) SORRISH: J . Chem. Soc. 1927, 761; 1929, 1158, 1611. (89) ~ O R R I S H , CRONE, 'YND S A L T M A R S H : J. Chcm. SOC.1934, 1456 (1934). (90) XORRISH, CROKE, A N D SALTY-ARSH: J. Chem. Sot., 1933, 1533. (91) SOI~RISH LYD I\;IRKBRIDE: J. Chern. Soc. 1932, 1518. (92) SORTOX: J. Am. Chem. Soc. 6 6 , 2294 (1934). (93) SOYES: J. Chem. Phys. 6 , 807 (1937). J. ilm. Chem. Soc. 66, 1754 (1933). (94) OGG,LEICHTON,ASD BERGSTHOX: (95) OGG,LEIGHTOS,AND BERGSTROY: J. Am. Chem. SOC.66, 318 (1934). (96) P.4TAT AND K O C H : Elektrochem. 41, 494 (1935). (97) QURESHIAKD TAKIR: J. Phys. Chem. 36,2670 (1932). (98) RABINOWITSCH: Z. physik. Chem. B19, 190 (1932). (99) IiYITCHIE .
