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1972
The Photochemistry of tetramethyl-3-thio-1,3-cyclobutanedione
Mason Ming-Sun Shen
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Recommended Citation Shen, Mason Ming-Sun, "The Photochemistry of tetramethyl-3-thio-1,3-cyclobutanedione" (1972). Electronic Theses and Dissertations. 4833. https://openprairie.sdstate.edu/etd/4833
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TETRAMETHYL-3-THIO-l,J-CYCLOBUTANEDIONE
BY
MASON MING-SUN SHEN
A thesis submitted in partial fulfillment of the requirements for tne
degree Master of Science, Major - in Chemistry, South Dakota State University
1972
SOUTH DAKOTA STATE UNIVERSITY LIBRAR fer -th:Ls
-7 - - -- -07 - D;;;/:...; TO MY PARENTS PHOTOCHEMISTRY OF THE TETRAMETHYL-)-THI0-1,)-CYCLOBUTANEDIONE Abstract
MASON MING-SUN SHEN
Under the supervision of Professor James J. Worman
photochemical reaction of tetramethyl-3-thio-i.l,3-cyclo The butanedione in the presence of oxygen and light yields tetramethyl-1,
)-cyclobutanedione and sulfur dioxide.
kinetics and mechanism of the reaction have been studied The thoroughly in different solvents and at different concentrations.
Results this study indicate that the mechanism probably involves· of singlet oxygen and state thione although triplet thione and ground
triplet xygen are not completely eliminated. o CONTENTS l. Introduction •••••••••••••••••••••••••••••••••••••••••••••�•••;••• 1 2. Purpose •••••••••••••••••••••••••••••••••••••••••••••••••••••••••• ? ). Results Discussion and I. The preparation and purification of tetramethyl-3-thio-l, 3-cyclobutanedione ••••••••••••••••••••••••••••••••••••••••• 8 II. The photocheiaical reaction of the monothione ••••••••••••••• 9 III. The rate of reaction and kinetic studies , ••••••••••••••••• �12 IV. The identification of the products •••••••••••••••••••••••••21 T mechanism reaction v. he of the ••••••••••••••••••••••••••••••23 Conclusions •• , •••••••••••••••••••••••••••••••••••••••••••••••••••30 4. 5. Experimental
;Description of instrumentation •••••••••••••••••••••••••••••••••••31 The preparation of tetramethyl-)-thio-1, 3-cyclobutanedione, ••••••32 The purification of tetramethyl-3-thio-1, 3-cyclobutanedione ••••••32 Photodesulfurization of tetramethyl-3-thio-1,3-cyclobutanedione,.35 The isolation of the tetramethyl-1, 3-cyclobutanedione,,, •••••••••38 The identification of sulfur dioxide . , ••••••••••••••••• , •••·• · ••••• J8 Desulfurization by singlet oxygen •••••••••••••. •••••••••••••••••••39 Fluorescence and phosphorescence spectroscopy••••••••••••••••••••40 Photochemistry of tetramethyl-1,3-cyclobutanedithione ••••••••••••4 1 The purification of solvents•••••••••••••••••••••••••••••••••••••41 6, Appendix•••••••••••••••••••••••••••••••••••••••••••••••••••••••••43 References•••••••••••••••••••••••••••••••••••••••••••••••••••••••51 ?. -----
TABLES
Kinetic data for a first order reaction with an TABLE I initial concentration of 0.098 monothione 14 N •••••• •• Kinetic data for a first order reaction with an !ABLE II initial concentration of 0.075 monothione 14 M ••••••• • Kinetic data for a fir�t order reaction with an TABIE III initial concentration of 0.010 monothione 15 M •••• •••• Kinetic data for a first order reaction in the TABLE IV presence of cyclohexa.diene 15 •••• • ••••••••••••••••• ••• Kinetic data for a zero order reaction with an TABLE V initial concentration of 0.098 M monothione 16 ••••• ••• Kinetic data for a zero order reaction with an TABLE VI initial concentration of 0.075 M monothione 16 •••••••• Kinetic da"i:.a for a zero order reaction with an TABLE VII initial concentration of 0.010 M monothione 17 •••••••• Kinetic data for a zero order reaction in the TABLE VIII ene 17 presence of cyclohexadi ••••••••••• •••• • •••••••••
TABLE Summary of photodesulfurization of tetrainethyl- IX 3-thio-l, J-cyclo butanedione 37 •• • ••••••••• •••••••• •••• 1
INTRODUCTION
first law of photochemistry, formulated in the works of The - Grotthus (1817) and Draper (1843) more than a century ago, states1
Only the light which is absorbed by a molecule can effective in be l producing photochemical change in the molecule . The law and its
consequences are commonly taken for granted by photochemists today.
the advent of quantum mechanics, the effect of light on matter Until
not properly derstood.2. a result, during the prime age was � As � photochemis� (-1920) numerous and wondrous photochemical reactions ar � discovered , but both useful application of these results and _ were 3 1 formulation of a unifying theory were lacking. From 1920 to 950,
photochemistry was perhaps considered the realm of the physical chemist
4 studied the details of photoreactions the gas phase • The who 1n
availability of new spectroscopic and analytical techniques during the
l950's to the present date and the development of imp�rtant theories concerning electronically excited states, reduced the difficuity in
characterizing the complex products of photoreactions and gave promise
of control of photochemistry2. In the last decade.the chemical literature to very large was a
extent crowded with studies involving the controlled photochemistry
of organic compounds,. particularly those containing carbon and hydrogen
only. More recently many studies have been extended to those com-
containing heteroa.toms such as oxygen, nit�ogen, and sulfur. pounds 2
The photochemistry of carbon pi bonded to unconjugated oxygen in 0 ud.ied1 ketones been exhaustively st • Similar st e on Azo has udi s methines (carbon pi bonded to nitrogen also ·been reported15. a ) have Although ce of photochemistry been done on compounds a rtain amount has containing the co ated thiones5, there n� documented reports njug are on the photochemistry of carbon pi bonded to sulfur i molecules n con ing system simple \.Ulconjugated chromophore. tain this as a The preparation and reactions of unconj'ugated docu thiones are mented elsewhere16 and in worlt it also been shown this has the l;J diphenyl-3-prepanthione (!) undergoes an accelerated dimerization ? presence of light to give the d.itheitane (2). in the
(1)
instability of its ability to·dimerize the The 1 and in
it impossible to establish the reaction clear cut dark make as a photochemicaJ. phenomenon of the thiocarbonyl chromophDre. This accompanied by the fact that cyclohexanethione known to (.l) vas undergo dimerization by both ionic mechanisms6 and free radical prompted to·seek more stable thione. us a unconjugated hv O=s (�)
In 1967 the synthesis tetramethyl-3-thio-l,)-cyclobutaned.ione of 8 reported is a bright ci-ystalline solid which, unlike · . '4\:!) was • -it red .o=(>=s
<4)-
9 most other unconjugated aliphatic thiones , shows no tendency to
polymerize ordinary temperatures, and is easy to dimerize or at very sublimes readily room temperature and has characteristic, handle, It at 8 somewhat camphoracious odor It is a very good compound.. to use • ·
photochemical studies the unconjugated thiocarbonyl chrom�phore for of do not have to worry complications of dimerization, because we about the
hydrolysis, etc.
The photochemistry of tetramethyl-1, 3-cyclobutanedione has (2) lO investigated thoroughly and therefore a base from been represents which to make comparison. photolysis of tetramethyl-1,J-cyclo- a The 4
by irradiation with ))6 light leads to a cl va.ge and butanedione run ea
tetramethylcyclopropanone, further reaction produce forms will tetramethylethene11•12•
co l-s¢propyl alcohol
(5)
It would realistic to e ect the photolysis of tetramethyl-3- seem xp thio-l,3-cyclo butanedione a lower light at 520 Q!) at wavelength or transition of the group, compare to the n�TT* nm (the �TT* C=S carbonyl group at )20 nm) to give transition of similar results.
0 H > -A+ o-Q=s cs 5
Another photochemical study on the carbon sulfur double bond which appeared in the recent literature is the photochemical reaction l of sulfines13, 4• Sulfines undergo a photod.esulfurization in the ----
hv ·-{ ----� [ - Sens. (0 0-0 ]
"
· C=o + SO. 2 / .' presence singlet oxygen. From this r action we also of might expect the photolysis of tetramethyl-J-thio-1,J-cyclobutanedione Q!) presence of oxygen and sensitizer to 'Wl.dergo a photodesulfuri- in the zation reaction as follows1
O=.Q=s+ 0.2 >
(4) !' o=Q=o + .so
(5) 6
. One could also expect dimerization to that reported of 4 si.'llilar · l to give unusual spiro compound. 2• for 7 the
From the foregoing discussion it is evident that the.photo-
of simple unconjugated thioca.rbonyl chromophore chemistry the has investiga.tion. In to understand more system avoided order of t.his undertook \investigation. we our PURPCSE
project was undertaken in an attempt to increase our This ·-- knowledge·of photochemical. reactiQns about compounds containing
unconjuga.ted thiocarbonyl chromophore. The ma.in areas the of
those studied include the reaction mechanisms and interest and kineti stwlies of the photochemistry of tetramethyl-3-thio-1,3- . c
lobutan on cyc edi e .
c. 8
DISCUSSION RESULTS AND
PREPARATION PURIFICATION TETRAMETHYL-3-THI0-113- I. THE AND OF
CYCLOBUTANEDIONE 8 method reported by and Davis for the The Elam synthesis of tetramethyl-J-thio-1,J -cyclobutanedione was used. Involved is a reaction tetramethyl-1,J-cyclobuta.nedione with phosphorus of pyridine. pentasulfide in
(b) (5) (4)
:following the reported method, it found that washing After was the products with solution of 0% sodium hydroxide did remove · a 1 not
tetramethyl-1,J-cyclobutanedithione completely and besides the <.Q.) monothione 4.ld.1 react with hydroxide to lower the percent�e - 1 sodium - . yield. Instead of following Elam's method completely, a little change
was made. If' one omits the wash procedure,. and chro�tographs the
products going through a silicic acid coltunn it will lead to a by . pu-rer product and the by product dithione for future 6 can be saved use. Another benefit of this revision that the starting ketone is is ..2 removed This modified method works because the completely. mainly 9
characteristic color of the products allorrs for easy separation
on the col . The monothione 4 is red, the dithione 6 orange umn is red and the to is colorless. dike ne j,
REACTION MONorHIO?lE II. THE PHOTOCHEMICAL OF THE {!!) The photochemical rea ti tetramethyl-J-thio-1,3-cyclo c on of butanedione in the presence of oxygen and light yields tetra @:) 3-cyclo butanedione methyl-1; (2). -�s 9=o.+ - o + 02 hv�· o so
• (4) ( 5)
e tion first in isopropyl alcohol solution. The r ac was run an ligh� so c a.·250 watt with no The ur e was R 40/3 Westinghouse Lamp . 23 emission 400 Visible and ultraviolet spectra taken belO\f nm • were
every tlre1ve hours or twenty-four hours during the �eaction. The
spectra. 1,2, and 3 the Appendix show the successive c s in in hange
absorption spectrum of 0.098 monothione 4 in iso yl alcohol the H prop
can observe easily the disappe ce a.t twelve hour intervais. One aran of peaks centered at 520 and 228 nm, co s to the the nm rre ponding monothione 4 also the forma.tion of dioxide intense and the sulfur peak a.t 270 isosbestic point was fotmd a.round 245 to 255 centered nm. An 10
nm and this indicated that the diketone the only major product ..2 was formed. Similar phenom na appeared in ·hexane and tetra- e carbon
s chloride olutions. e e of gas liquid chroma.tographs, nuclear An· xampl magnetic resonance spectra and infrared spectra follo the reaction wing of a 0.089 M carbon tetrachloride solution are shown in the Appendix.
In the gas liquid chromatographs the peak of retention time 770 sec
is_ for the monothione and that of 445 sec is for the diketone ,5.. 4
The decrease of the peak for 770 sec and increas.e of the peak for
445 sec indicated the decrease of concentration of onothione m Q±) and in ease the concentration of diketone .5. respectively. The cr of estimated l'ield from this chromatograph is a.round.71%. In nuclear magnetic resonance spectra, the chemical shift changes from l.JJ ppm to 1.20 ppm corresponding to the change from the monothione 4 to · diketone The yield is 75% estimated from t ese spectra. j. about h The infrared spectra s,llows he of the 1800 and 128.5 t disappearance l l cm - bands and the th intensity of 1740 1715; 1687 cm- increase e �- as the reaction proceeds from the monothione to the diketone � .,2. in The reaction was run the dark and there was no change in the visible absorption spectra of the monothione 4 which establishes
light. the reaction is dependent on The reaction was also run in the :presence of u.�ht but bubbling nitrogen through instead of oxygen, and no occur d in the visible spectra of The con change e 4. clusion can made that this reaction depends on th the presence be bo of oxygen and light. 11
Using MPF spectrophotometer the fl uoresce. nce spectra of an
the monothione 4 were taken in various solvents. In the presence and
absence of oxygen at room temperature, no measurable amount of
fluorescence could be detected by exciting the monothione 500 4 at
and observing emission from 500 to 800 If the monothione is nm nm.
going to the singlet state, self-quenching must be taking place
since no radiation process was recorded. A similar non-radiative
phenomenon was no ed taking the phosphorescent spectrum at 77°K � by in EPA. The possibility exists that the triplet of the monothione
is below 800 and therefore would not be detectable with avail- -4 nm . able instrumentation. would appear that fluorescence and phos- It phorescent spectra will not establish whether the reaction proceeds via the singlet or triplet state. The low temperature fluorescence did show a very weak emission at 540 but this inter- nm data must be preted with some cautian. It could mean that there is some singlet
4 i generated under these conditions where s f- monothione be ng e l quenching would be eliminated but small amounts of impurities also cause such low temperature emission.
ndica e emission Data obtained from the Turner Fluorometer i t d an
660 in the presence of oxygen. No such emission was noted in at nm the absence of oxygen. There is no explanation for this at present.
Using 0.101· cyclohexadiene, a triplet quencher, triplet energy M 8 52.5 kcai1 , in the isopropyl aJ.cohol solution in monothione. 0.096 11 will increase the reaction rate, and the reaction will be complete
· in 2.5 days. This is an indication that the reaction probably goes 2 1
through the singlet stat to some extent. A possibility is that the
singlet monothione � sensitizes cyclohexadiene to the triplet which turn sensitizes the oxygen to the singlet which will give a larger in concentration of singlet oxygen to react with ground state thione and therefore increase the reaction rate.
Singlet oxygen19 was generated by reacting hydrogen peroxide
0 sodium hypochlorite2 , and was reacted with the monothione. The ·and reaction was complete five minutes and gave the same product 1n j. The monothione also shaken separately with hydrogen peroxide 4 was and with sodium hypochlorite no reaction took place. This is and strong evidence that the reaction can go via a singl:-et oxygen mec'l'Janism.
Dye-photosensitizer21, methylene blue, was added into a solution of monothione 4 in an attempt to sensitize oxygen to a singlet state, but reacted with the monothione No information could obtained it 4. be from this reaction.
III. THE RATE OF THE REACTION KINETIC STUDIES AND
The reaction rate varies in different solvents and the presence of sensitizer or quencher. The 0.098 M isopropyl alcohol solution of the monothione undergoes the photodesulfurization reaction in three 4 days. A similar reaction of 0.101 M monothione in "hexane solution 4 and o.8 in carbon tetrachloride solution took five and one day, 9 M days respectively. The different rates of the reaction in the different solvents could be due to a solvent effect. The most important factor of the solvent effect however solubility of oxygen in the is the 17 different solvents. The solubility of oxygen in carbon tetra- lJ
chloride is the largest of the three� isopropyl alcohol is next and
helCalle is the lowest. This appears to be the main .reason why the
reaction will go the fastest in carbon tetrachloride, slower in
isopropyl alcohol and the slowest in hexane.
A 1.02 M carbon tetrachloride solution of the monothione under 4 the same conditions, shows no evidence that a reaction takes place even after four days. This probably is al.so related to the oxygen
·solubilities. A more detailed explanation will be given a later in section,
The order of the reaction being investigated was based ma.inly on kinetic studies. Because of the high volatility of hexane and carbon tetrachloride, it is very to get a stable decreasing ha.rd peak the ultraviolet spectra and so, this reaction was studied i1i only in isopropyl alcohol solution. The calculation done main was
by an IBM J60 computer. The program language used is PL/I. A completed program is presented in the Appendix. The data obtained
VIII, are listed in Table I through where T is the time in hours from the beginnillis of reaction, A is the absorbance, CT is the the concentration of the monothione in molarity, CK is the concentration 4
. of the diketone in molarity, and K is the rate constant for a ..5. first order reaction or a. zero order reaction in reciprocal hour or molarity per hour, respectively.
269661
SOUTH DAKOTA STATE U ·1VERSITY LIBRA X. 14
TABLE I. KINETIC DATA FOR A FIRST ORDER REACTION PHO?ODESULFURIZATION OF MONOI'HIONE 2-PROPANOL IN THE PRESENCE OF OXYGEN IN
THE CONCENTRATION OF THE SOLUTION IS .0972021 M T A CK K (HR) (M)CT (M) . (HR-1) 0 .097 12 .079 .018 .01677190 24 .055 .042 .02378635 .035 .o62 .02810740 36 .018 .079 .03509779 4860 .ooa .089 .04145069 72 .002 .095 .05344468
TABLE II. KINETIC DATA FOR A FIRST _O�ER REACTION PHCYrODESULFURIZATION OF MONOTHIONE IN 2-PROPANOL IN THE PRESENCE OF OXYGEN
THE: CONrnmrrRA.TIO?i OF THE SOLUTION IS .0751295 M T A CT CK K (HR) (M) (M) (HR-1) 0 .725 .075 12 .509 .053 .022 .02947694 24 .272 .028 .047· .04084872 .oa5 '.009 .066 .05954223 36 .025 .003 .073 .07015193 48 15
III. KINETIC DATA FOR A FIRST ORDER REACTION . TABLE PHC1rODESULFURIZATION MONOTHIONE 2-PROPANOL IN THE PRESENCEOF OF OXYGENIN THE CONCENTRATION THE SOLUTION IS .0104663 M OF T A CK K (HR) (M)CT (M) .. HR-1 ( ) .101 .010 120 .oo6 · · ..010040 .001.o04 .009. 24
TABLE IV. KINETIC DATA FOR A FIRST ORDER REACTION .. PHCfl'ODESULFURIZATION OF MONorHIONE IN 2-PROPANOL HE PRESENCE OF OXYGEN CYCLOHEXADIENE IN T AND CONCENTRATION OF THE SOLUTION IS .0957513 M . THE CK ' (HR)T A (M)CT (M) (HR-· K1 ..) .096 120 .5.92243 .054 .042 04742753 .335 .035 o61 . .0422?419• 24 .187 .019 ..076 .04437785 )6 .1:n .014 .082 .03976522 48 005 .001 .095 .08698785 60 .• 16
V. KINETIC DATA FOR A ZERO ORDER REACTION TABLE PHOI'ODESULFURIZATION OF MONOTHIONE IN 2-PROPANOL IN THE PRESENCE OF OXYGEN
CONCENTRATION OF THE SOLUTION IS .0972021 THE CT CK K M (THR ) A (M) (M) .. (M/HR) 0 .097 12 .079 .018 .00150000 24 .055 .042 .00175000 .035 .o62 .00172222 36 .018 .079 .00164583 4860 .008 .089 .00148333 72 .002 .095 .00131944
. \
·-. VI. KINETIC DATA FOR A ZERO ORDER REACTION TABLE PHOTODESULFURIZATION OF MONOTHIONE IN 2-PROPANOL THE PRESENCE OF OXYGEN IN .. CONCENTRATION OF THE SOLUTION IS .0751295 M THE CT CK K (HRT ) A (M) (M) (M/HR) 0 .725 .075 12 .509 .053 .022 .00183333 24 .272 .028 .047 .00195833 .085 009 .00183333 36 .025 . .003• .073.o66 .00152083 48 17
VII. KINETIC DATA FOR A ZERO ORDER REACTION TABLE . PHarODESULFURIZATION OF MONOTHIONE IN 2-PROPANOL IN THE PRESENCE OF OXYGEN
. .---· CONCENTRATION THE SOLUTION IS .0104663 M THID OF CK K T (HR) A (M)CT (M) (M/HR)
.101 o· ..010 .005 .00500000 12 .0.04010 .0o0401 .009 .00375000- 24
VIII. KINETIC DATA FOR ·A ZERO ORDER REACTION TABLE PHorODESULFURIZATION OF MONCYI'HIONE IN 2-PROPANOL , IN ·PRESENCE OF OXYGEN AND CYCLOHEXADIENE THE'
.. THE CONCENTRATION OF THE SOLUTION IS .0957.513 M A CT CK K (HR)T (M) (M) (M/HR) .924 ,096 0 .523 .054 .00350000 2412 .335 .035 .o61.042 .00254167 .187 .019 .076 .00211111· )6 00170833 .1:37 .014 .082 . • 4660 .005 .001 .095 .00158333 18
FIG I o.oa Pho�desulfurization
Monothione ot (1) 0.06
o.o4
0.02.
FIG II
"""' o.o, PhotodesulfUrization � "'"' J of Monothione � � (2) v
QJ o.o4 � .�
�r 0 � D.02
+:� ( Mour.s) 19
.ooq
.001· FIG III - � Photodesul.f\J.rization "'-.J .005 of Monothione (J) \) � 0 v • 00� OI s: <> � +- 0 s: 0 �
.oo\_._--��----�--�------��------1,.---�----�.a...------.11 , 2 � 4 � T;,_.e:., (Hours)
.09 FIG IV
PhotodesulfUrization
-.os of Monothione (4)
.03 0�
�
1Qs: 0 -�
12. 24 20
The calculation is based on the ultraviolet spectra. The n-+TT* transition of carbon sulfur double bond an absorption at has 520 with a equal to 9.65 and the calculation is based on the nm e decrease of this peak function of decrease the concentration of as a monothione 4. The expression is as followsa
CT m l e,T x where is the concentration of monothione CT is the absorption at 520 at time t At nm is the molar absorptivity of monothione &r l pa.th length through the sample and is equal to 1. is the The concentration of diketone expressed by the formula j can be below;
where is the concentration of diketone CK A and A the absorption at time o and t respectively 0 t are a.nd are the molar absorptivities of monothione and � 8K diketone, respectively.
The first order rate constant and zero order rate constant are calculated based on the following equa.tions a 21
plots of time vs concentration (FIG.I and II) show that The reaction of 0.098 M and 0.075 monothione solution the the M in presence of oxygen are zero order monothione And the plots 1n 4. o� -time vs log concentration show that the reaction of 0.010 M
solution and 0.097 monothione solution the presence aonothione M 1n cycolhexadiene are first order in monothione·. !!:• The detailed of
expl.ana.tion of his data will be the reaction mechanism section. t 1n
IV• I IFICATION OF THE: PRODUCTS THE DENT identification bas been done infra.red spectroscopy, The by nu.cl.ear resonance spectroscopy, gas liquid chromatography magnetic mixed melting point. The identification of the sulfur and by di e9 howeverl problem. ox1d was a The first indication of the
formation of sulfur dioxide was found in the condensate which
:resulted from the evaporation of the isopropyl alcohol from the
of !f; 1n isopropyl alcohol in the ·presence of oxygen and reaction light. ultraviolet spectrum of the condensate is shown in The (b). The ultraviolet absorption maximum at �7� resembled FIG. V nm · properties of an authentic sample of FIG . the spectral so , v _ 2 (a), which had ·absorption maximum at 76 The 6 nm blue an 2 nm. shift the reaction &le probably is due··to the slight difference in polarity of the two solutions. The other evidence for the pro in duet:ion of sul:.tur dioxide came from wet chemical techniques. The
during the reaction interval gas coming out of the reaction was
trapped a 1% sodium hydroxide and this solution gave much by Af'ter neutralization by hydrochloric acid, the solution information. 22
- ,.0 - • ,..... (/) C'd +> � 0 � (l) 'd . "O 0 ·rf � >< A 0 .,� ft-I "O 0 S.. rd e b0 CJ ';J(/) 0. (f) () or-I ....,, +> (l} s= ...... 0 •rl 1! > ro M +> � M :::> 'B"'
> d � 2.3
was tes ed an and the t by using iodine solution22 itdecolorized iodine. The reaction must be as follows1
This is viden e for the presence of sulfur additional e c dioxide.
The sodium hydroxide used to trap the gas comin out of the rea tio g c n
by using p was also tested barium hydroxide and a white preci itate
formed. This white precipitate dis�olved when the solution was
acidified using hydrochloric acid. The rea tio fo l c n is as l ows a
+ 2NaOH so2
The sulfite known to be so ble barium is lu 1n acid solution. This
data strongly supports the presence f sulfur dioxide rea ti n .. o as a c o
product.
THE MECHANISM THE REACTION V. OF
Two summarized in Scheme l and in Scheme possible mechanisms are
2. In Scheme 1, the thione 4 is first ex ted to t� singlet state. ci
·The singlet state thione t a sensitizer to ex ite triplet can ac as c oxygen to th inglet state and the singlet thione will go to the triplet e s
state. The singlet oxygen will then react with ground state thione
and could form a reaction intermediate 8. This intermediate 8
mmedi tely to form the pr ucts diketone ..2 and sulfur could decompose i a od 24
hv =S 0=
4
-� �s + 1 o-o� I
�s + 10-0� --�> o-=
,, -8 !
so + =O so + . � 01 ----+- so"
Scheme l 25
hv O= s
4 1
t_is + 10-0� > J8
SO -+ O= =o
5 . + _SO . i2 0.2. so.2..
Scheme 2 26 monoxide. The sulfur monoxide can then react with the oxygen stream and form sulfur dioxide.
Scheme the monothione 4 is excited to the singlet state In 2, and then after an intersystem crossing produces the triplet state.
The triplet thione can react with the oxygen stream which is in a triplet state give the intermediate 8. This will collapse to and produce the di eton and sulfur monoxide which leads to sulfur k e j, dioXide. The reaction of singlet oxygen�O in the presence of monothione
4 both in the dark and under light is comp eted in five minutes l and gives diketone This means that the thione will react with i• singlet oxygen readily even in the ground state.
incre e in the concentration of the thione will slow down An as the reaction and this is probably due to the limited solubility of oxyge in th certain insignificant amount n e solvent. �This would give a singlet oxygen to xeact with excess thione and no detectable of amowt of products would fo\.llld. Self-quenching of the thione at be large concentration could also inhibit the reaction. The kinetic data indicated that the reaction is a zero oroer tion mono reac in thione 4; om the mechanisms it bimolecular reaction but fr should be.a by reacting monothione 4 with singlet oxygen (Scheme 1) or by reacting triplet monothione with tri et oxygen (Scheme 2). e l tio pl An xp ana n this apparent anoma.lous behavior could be follow the low of as sa 27
produces limited a.mount and; there- intensity lamp only a. of photons
fore1 the rate determining step could be the first step, that is, to
excite ground monothione 4 t.o the first excited singlet. The state
comparatively large e ces of monothione makes the reac io x s amount 4 t n
only dependent on the number of p to and this is a constant rate ho ns
throughout the reactio . This makes t e reaction pse o r er n h a ud ze o ord in Only a.t the very end of the reaction do it appear monothione 4. es order· monothione in other at a low to be first iri .!±. or irords very concentration. FIG. I t o h IV). At this time, monothione 4 (See hr ug the third step is the t determining step. ra e £act that the presence of cyclohexadiene will cre e the The in as is seen at fL.""St someuha.t anomalous. If it were reaction rate
quenching triplet of the thione, it must certa.inly slotr down the tbs reaction and his is definitely not observed. kinetic t The data .. h cyclohexadiene the reaction is first suggest that in t e presence of
order. This co d interpreted to mean that cyclohexadiene is u.l be helping to generat-e more s let oxygen. plausible sc e is show ing A h me
'belcnn o=Q·s hv 28
Sufficient singlet oxygen wuuld then be available to allow for first order kinetics. The oxygen solubility dependent rate of the reaction also supports the singlet oxygen mechanism. If the reaction goes through triplet thione reacting with triplet oxygen Scheme 2), the comparatively ( large excess amount of oxygen (as we suggested to explain the kinetic data should not affect the reaction rate. This is contraxy to what ) we observed. It is impossible from the present data. to completely eliminate the reaction of triplet thione with triplet oxygen but most of the data suggests a singlet oxygen mechanism. In order to eliminate triplet oxygen, we must determine the triplet energy of the thione and then choose a quencher with slightly lower energy. Cyclohexadiene has a triplet energy of 52.5 kcal
(550 nm and this is too high for the triplet of the thione. ) experiment which would establish that excited thione Jul is definitely genera.ting singlet oxygen would be to coat the inside of a glass tube with a thin layer of thione and then pass oxygen gas . through the exciting the thione at 520 h e tube.while nm. T e ffluent oxygen could then be passed into a singlet oxygen acceptor. such as . . 24 antb:racene to form a known addition product well • Detailed work on the dit ·one 6 will al.so give some interesting information. Some preliminary work lltdicated a ·hexane solution of dithione 6 in the presence of oxygen and light react twice as will 29 fast as the monothione under similar conditions. This suggests 4 that the two.thiocarbonyl groups could excite twice the amount of singlet oxygen and this would increase the reaction rate. 30
CONCLUSIONS
The phot esulf atio of tetramethyl-3-thio-1•3-cyclo od uriz n butanedione 4 been thoroughly studied. The products were - . ha.s ide tified as tetramethyl-l;J-cyclobutaned.ione .2,·a.nd sulfur n dioxide. The kinetic studies indicated that the react on iso- i 1n propyl alcohol in the presence of oxygen is zero order monothione 1n
and this is o bly due to the limited amo t of singlet oxygen !t. pr ba un generated by the s et first order reaction in mono- ingl thione. A - thione .!! is obtained in the presence of cyclohexadiene. The mechanism of the reaction probably involves singlet oxygen although a triplet oxygen mechanism is not completely eliminated. The photochemistry of dJketone also been studied and shows that §. has a reac on takes place to give the diketone or similar ti _2; but m e detailed studies must be done before photodesulfurization of thione
be defined as a general. tion. can reac
... ·- EXPERIMENTAL lESCRIPl'ION OF INSTRUMENTATION1
- Visible and ultra.violet spectra were on a Beckman ratio run DK-2A rding spectrophotometer. Samples were in reco l:'\m silica. cells as d11ute solutions various solvents. in Infrared spectra were on either the Perkin-Elmer Infrared run 700 Spectrophotometer or the Perkin-Elmer 521 ting Infrared Spectro- gra phOtometer. Samples were neat, as nujol mulls, or as KBr pellets.· run pellets we� prepared on a. Carver Laboratory Press Model KBr 13.
Nuclear magnetic resonance spectra were obtained by use of a analytical nuclear magnetic resonance spectrometer. Va.r.ian A-60 Samples were nea.t or as solutions carbon tetra.chlorid run in e. liquid chromatography on a Beckman GC-2A. Gas was run Either nitrogen or helium used as the carrier gas a.t a gas was pressure 15 ,.. column us d 1/4 The temperature was The was a. inch ps�. 16o0c. e by £eet column pa.eked with 15% SE-30 on 42-60 mesh chrome- 10 aJ.umiiiwn sarb P.
Melting points were obtained using Thiele tube contain a. ing · oil� and uncorrected. para.fin are Fluorescence and phosphorescence spectra:. ware run a Perkin- on EI..er spectrophotometer; at the University of Wyoming� Laramie; MPF-2A
Wyoming. experimental work performed at South Dakota State The was Un1vers1ty; Brookings; South Dakota. 32
THE PRF.,PARATI TETRAMETHYL-3-THI0-1, 3-CYCLOBUTANEDI ONE 4) 1 ON OF ( The procedure used here was a modification of the one used by Elam Da.vis8• and A solution of 150 g (0.67 mole) of phosphorus pentasulfide
(Fisher Scientific co.) and 210 g (1.5 of tetramethyl-1,3- mole ) cyclo edione (Aldrich Chemical. Co.) in 500 of pyridine was but.an ml
with stirring. The reaction was stopped after minutes. reUuxed 40 The hot sol�tion was allowed to settle. The settled solution was decanted. The solid was heated to �oiling with 125 of fresh ml pyridine� then cooled and decanted. The combined pyridine solutions were distilled.ra.pidly without fractionating at 35 to .50 mm (Hg) order to remove the last of the inorganic material. The 1n pyridine removed vacuo (J by fractional. distillation (FIG-. VI) lras in O mm Hg) until the temperature reached The distillation residue was 6o0c. taken in 150 of h xan and the solution was decanted up ml warm e e , from sma.ll amol.Ult of and cooled to 20 C. The crystaJ.s of a tar 0 . diketone were removed by filtration and washed with a small amount j of hexane until the color been The filtrate all red had removed. was disti1led and a fraction collected between. 160-170 0 c.·
THE PURIFICATION TETIWlETHYL-3-THIO-l;-3-CYCLOBUTANEDIONE (4)1 OF The products o ed above not very pure and usually a btain are are mixture of the monothione dithione and diketone ,2, because of the 4, 6 similarity of the boiling points. The best way to s�parate them is to 33
Heat ln!3 b 1-. ''-ant le Distillat ion 2 . :n l 25Fl0as1 {' Disti llation 3. Head 8 C'.!1 2 . 5 gl(4�ass c(n) -pa c:<:ed. 5 1nm 'nr!l :3 lass 4. tu5 bings 7
Ther"!lor:-ne l, er 5. Cool 6. ins water intake Coo lin::; vra ter 7. out let
Vacuum pump 8. Cooling jaC!{et 9. 10 . ml Dis'tillation Fl250as k
The Column Dist i llation Equ ipment for Pyr1d 1ne FIG VI
1n preparat ion of tetra�ethyl-3-thio-1, 3-cyclo
butanedione . column chromatography. A colunm, cm long with a J diameter, use 80 cm was pa.eked ha.lf fUll with silicic acid Matheson Coleman Bell and ( & ) hexane used the eluting solvent.. The crude products were dissolved as in amount of hexane. The hexane solution pou:red the a minimum was into coiumn. After the red solution was run onto the silicic acid column, all the sample eluted hexane. About one hour later, the solution was with was separated three layers. The first lower orange layer is the into dithione 6, the second red layer is the monothione 4 and the light last layer the diketone .5.• To separate 10 g of the products yellow is \ es e1ution with 5 liters of h e over a three day period. usually tak exan The purified so1utions then evaporated under vacuwn and in the were of the monothione a d solid was obtained, yj.eld 50%. A 10% case re yield of dithione 6 was a.lso obtained. The rema.1ning material. the was ma.inly unreacted starting material.. The products were checked
gas chromatography and �MR . If the samples showed contamination, by a second run through the column was necessary.
T monothione 4 melted at 15(-158 0 C1 rared . he purified inf -1 ' a.t 1800, 1770, 1450, 1290 and 1125 cm ; rimr spectrum. absorptions singlet. at ppm; visible and ultraviolet absorptions 1n cci4, i.:33 in 228 ( 8700),( 270 nm (JOO), 318 nm (100), and .520 hexane, A. nm � max & (9.65). ma purified d.ithione 6 melted at 123.5-125°ci infrared absorp- A -1 tions at 1460, 1265 and 1075 cm nmr spectrum cc1 , singlet at r in _ 4 l.4o ppmJ visible and u1traviolet hexane 227 absorptions in A.max 21600), 298 nm (409), and 500 nm (22.4). ma ( & • 35
PHOTOIE3ULFURIZATION TETRAMETHYL-3-THIO-l, 3-CYCLOBUTANEDIONE 4 OF ( ) 1
A method was devised for our purposes where irradiation of the solution could take place through a Kimax filter and in the presence
Qxygen Linde , was first passed of a stream of oxygen (FIG . VII) . - ( ) through a reducing valve at 5 lbs per sq inch of pressure Then • . uare . it was forced through a calciwn chloride drying tube to remove any trace of water, finally it was bubbled through the reaction tube shown in Figure VII.
The reaction tube contains two parts, one is a L tube with a glass frit M) and 19/22 female glass joint one end and (Pyrex 20 in another part is a 19/22 Kima.x reflux condenser where the glass frit acted as a support . The reaction solution was supported by the oxygen stream to prevent its dropping. The oxygen stream was passed through another reflwc condenser containing glass beads in order to condense the so1ution hich was being carried out by the oxygen stream. The gas coming out was conducted by glass tubing into a flask which contained 100 of 1% Na OH solution. ml The solutions used this experiment were a isopropyl alcohol 1n solutions, hexane solutions and carbon tetra.chloride solution�, a summary of these reactions is shown in Table IX. Tua e 1. Calcium 0hlori1e Dryin� �1Jb e �. L Pyrex Fr it Corning) 3 Glass . Reaction Tub e (20� 4. Solut ion 5 . Reaction (Shadow) 6. Rs f lux Condeneer �JO ml Erle ��ey er Flask 7 . Sourse (25� watt Li�ht R g. We stinghouse 40 /3 'Jas La �p ) FloT11 �ate �-�e t er 9. ock l�. Three �Va y St ope
1 --��-i....:!-�-Y�
The Photodesulfurizat ion FIG VII Ap?ara�us 37
Summary of photodesulfurization of tetramethyl-J-thio- · TABLE IX1 l,)-cyclobutaned.1one 1
-
Solvent Concentration Sensitizer Completion ... (M) Time (days)
Isopropyl alcohol 0.098 J
Isopropyl alcohol �.075 2
Isopropyl alcohol 0.011 1
\'. I opr pyl 0.101 s o M &1.cohol 0.096 cyclohexad.iene 2.5
Iaopropyl 0.099 M alcohol 0.101 methylene blue
Hexane 0.101 5
Hexane 0.010 i .5
carbon tetrachloride 0.089 1
carbon tetrachloride 0.009 0. 5 38
these reactions run in the presence and absence of All were 22 and in the presence and absence of ax.ygen except for the light carbon tetrachloride solution.
The reaction was followed by ultraviolet and visible spectros copy and gas liquid chromatography. Samples for analysis were taken every twelve or twenty-four hours.
THE ISOLATION OF THE TETRANETHYL-1,3-CYCLOBUTANEDIONE (5) 1
After the reaction was completed as determined by ultraviolet and visible spectroscopy, that is the disappearance of the absorption at 520 nm and at 228 nm was complete, the solution was evaporated at room temperature _!!! vacuo and the concentrated solution was left in the cold room for twenty-four hours. A yellowish product crystalized out. The compound was then recrystal.ized from warm hexane . The infrared, nuclear magnetic resonance spectra and gas liquid chromatographic retention time were recorded and all of them indicated the product to be identical with an authentic sample of the diketone (2), yield 75%.
The mixed melting point also was taken. The pure diketone · ..2 ° . ° melted at 113-114. 5 c; the product melted at 107-111 9. The mixed ° melting point was llo-113 c.
THE IDENTIFICATION OF SULFUR DIOXIDE 1
The identification of one of the products "sulfur dioxide from " 39 the photo1ys1s of tetramethyl-l-thio-1, J-cyclobuta.nedione Qt) was done two different methods1 by I. condensate from the evaporation of the completed The reaction solution was first used for identification of sulfur dioxide. ultraviolet spectrum of the condensated isopropyl The alcohol solution had an absorption at 270 nm. This was compared to the 276 nm absorption of an authentic sample of sulfur dioxide (Matheson Co. ). II. stream evolving from the photolysis (FIG. II) The oxygen was trapped by 100 1% sodium hydroxide solution during the ml reaction period. The sodium hydroxide solution was analyzed for the presence of sulfite. After the excess sodium hydroxide was neutralized with hydrochloric acid, the presence of sodium sulfite 13 can be proven titration and decolorization of iod.ine. . by he presenc of sulfur dioxide al.so can be proven by the III . T precipitat.1.on with barium hydroxide. The trapped gas sodium in hydroxide solution can form a white prec�pi��te with barium. hy droxide9 this indicates the presence of sulfate or sUlfite ion.
This precipitate will dissolve after acidification with hydro chloric aci.d, and this proves it must be sulfite.
SINGLET OXYGEN1 DE5ULFURIZATION BY The preparation of singlet oxygen has been reported by Foote 20 and co-workers This involves a reaction of sodium hypo his • chlori with hydrogen peroxide. The· sodium hypochlorite (5.2.5%) te 40
used provided by the Hilex Company. The hydrogen peroxide (30% was ) supplied by J. T. Baker Chemical Company. The procedure used was was
as follows1
isopropyl alcohol solution of 0.102 M tetramethyl-3- A_?O ml thio-1 ,3-cyclobutanedione placed a 250 separatary {!!) was in ml funnel and 50 of 5.25% sodium hypochlorite solution placed ml was another separatary funnel. Both funnels were attached to a 250 1n 3 neck fiask containing 50 of 30% hydrogen peroxide which was Ill ml being stirred magnetically. The s�ium hypochlorite solution was added dropwise 1nto\ the reaction flask and a large amolUlt of gas , formed immediately. The red monothione solution introduced 4 was next into the reaction flask, and the reaction started. The gas evolving from the reaction wa.s trapped by 100 1% sodium hydroxide ml solution. positive analysis for sulfur dioxide was obtained as A previously described. - This reaction both in the dark and exposed to light completed five minutes. Tetramethyl-1,J-cyclo was in butanedione was isolated by evaporating the isopropyl alcohol . (2) . and water mixture. It was identical in all respects with that of an authentic sample. There were n·o apparent reactions when the red monothione was � shaken with hydrogen peroxide only or with sodium hypochlorite.
FLUORESCENCE PHCSPHORESCEliCE SPECTRCSCOPY1 AND The fluorescence of the monothione 4 done both the was in 22 presence and absence of oxygen • Irradiation of the monothione 4 41
in isopropyl alcohol solution in the absence of oxygen does not
have fluorescence the light source has a wavelength longer any i:f' the presence of oxygen, there is a fluorescence - than 400 nm. In 660 if monothione 4 solution is irradiated at 620 at # nm the - nm. This on B work was done the Turner Mod.el Fluorometer. the Pefkin-Elmer MPF spectrophotometer no detectable Using room temperature fluorescence could be detected when the sample
ted at . 500 was irradia nm. A temperature fluorescence spectrum did indicate a very 1ow weak e ion at 54o miss nm. ° The 77 K phosphorescence spectrum was taken at in EPA exciting monothione at 500 No phosphorescence detected from the 4 nm . was 500 to 800 nm.
TETRAMETHYT.t-1,3-CYCLOBUTANEDITHIONE PHOl'�HEMISTRY OF (6)1 A s:lmilar reaction, photodesulfur�ation of the dithione 6
also been done . A 0.099 M hexane solution of the dithione (6) has irradiated by visible light in the presence of � oxygen stream, was ._ The o -red solution was decolorized after three days irradiation. range The gas l.iquid chromatograph indicated the presence of the diketone
2 and some other undefined products. Further studies should be
done before a complete report can be written.
THE PURIFICATION OF SOLVENTS1 Four liters of hexane was stirred with one liter of concentrated
sulfuric acid for seventy-two hours after which the sulfuric acid
was changed with a fresh one and - the mixture was stirred another 42
forty-eight hours. The upper· layer was removed . and washed with two of water three times. After the water was separated, the liters hexane dried over a.nhydrotis magnesium sulfate with swirlin was g for two hours. The hexane then filtered, passed through a was
ge1 and then through an column (80 x 3 cm . silica. aluminum cm ) prior distillation. to
· Carbon tetrachloride was mixed with anhydrous phosphorus pentoxide. The mixture was distilled into a vessel anhydrous with potassium carbonate powder t fo__r storage. The solution samples 1n i were taken from this vessel. 4J
APPENDIX This section contains the ultraviolet and visible spectra,
infra.red spe.ctra, nuclear magnetic resonance spectra and gas liquid chroma ographs which describe the photochemical reaction of . tetra ·aethyl-3-thio-l, 3-cyclobutanedione it proceeds. In the Q!) as Results and .Discussion Section these spectra referred to are in order varify conclusions made on the reaction mechanism to . PL/I computer pro ram is al.so attached for the documented A g kinetic calculations. �- ·
· � _. - :--; �- ·=-:-: :: i · • . . ·1 . . : j
. . - , TJ LT RAV IOLS1' 3 "?E'.';1·RA . . .
Ult re. violet S1)ectr.a f o llo-;-: the .... �-�-:--!:_ l·-.: · · · · • - . · : �r : ;: .. ! t i�� . ohotodesulfuriza r6action - . ' . . --·- , 3-cy�lo ·-·-·-·-· of tetra�ethyl-3-t�io-l •• .•• j _ .. ; . j ;· . ·.. : :. ... : :·.. . . - ...... I : but ane� ione t • �-:_- : i .. · : .. in iso,rooyl alc ohol . . •:·; •.-)._• t I•• ··:.::•• .. I . 9re sence of e • I • sol ut i on in th . --� � ·�·:.-_f -�:· ; ! - . . . oxyr_:;en . ' ......
0urves :
450 {SJ . 1 Begini�g of the re�cti:n
2 -C_3 : Tal�Em every l� hours SP�0T RU �.': 1. Vis ih le s�ectrg, of the � Reaction co�Jlet� react ion ta�en every twelve ho�rs .
f.:� �
. ,. - : I t·
•• I •
...... : . . ...··.:· : - ; · . . '[: - .. - ...... - • • - · - . : j . . · . :: : : .. ·; : . � l - ...... · · · __ _ - _ ._· . · . ·_: � - : ! ..· : : ,::· - •L , :-t-:-r • I ..: .i . . ·: : i ;· ' • : . . • • ; j . . ___ ! : . ! � : .' . --=..:. -
:·· ·• ' '�' -·· · ·- ,· ··: ·_ : I ;�L..:�'. :. �o). .... C-.J v "" . r.,."' - · - : . •I :-'.·- :- � •· : � :_:-;::v.� -. ·- - .. i : I
- , . ., .. -...... - -- ...... • . j· :. I ••·•
�o �IO �10 }I O no .ir9 .ll O
..... S��CT 2. spectra . . n..... R T:! Ult rav iolet of the SPECT RJ� 3. Ultraviol3t s?ectra of t � react ion taken every twelve hours . react 1011 t e..ker'l every t,;·rnlve h0�n's . (Ten ti�cs dilut ion of spe ctru� 2 )
+.- \..11 $(l) ,--J {J) 0. >-· �::: r, ' :.� 0 ,.... 0 \.0 0 X! C' .. . 0 '< "· (...... -�. ..-l ....� � <) {\) ,..J � .. n-; .,-I c �· .;.) �-1 0 .. r' .--' f C)
rl
' . I • I • I • ' . I • I • l • I .. I • : r� � .... I • z I • 0 c� u � :r: ..... 0 z CJ .J Ul � 3
.... - . � . : � . . .. :
�' �. 1.t> (\) 1-' ·I :> r, I C1 -f ...-J: <\� • -·--,'1.0 �.? ?.� I I �b 1 ---
' • I ; I• .1 ' • • · NMR SPECTRAi 1 ,, ,1, : , : . . i' � �-=::," ! ' . .. . : ..... -! ·- • ! ' ·: .· . \_ , ·. ! ' magnetic resonance ; . - . : ·Nuclear - . - _! - . , '•I . . �· ...... -: : . �.. . I ;. : spectra following the reaction ·.i I ..i -<.-- . :.-·: ,. !. in carbon i tetrachloride . 1.: : : . I ! . solution every twelve hours. . . . !I . . . i ! . i •'� . . � I . . P.• � .. . -· �. , � . ! � . : . . . _, :! �; : I .. !;. ,: .·: , - - • : SCLVE�T . ..- . -·: ' I' I: .. ,, ,_;�!.� - - - .. • ' i .,.., ...... , ...... -� _ ) _ :I • . .: -..tit. ...: "i - - ·c : ...�=, . l .J. . . !1· · -r.. ' I - ....- - - - - • I - '- • . , .... . _.,J ·H . 1: �C • t J rl' T;?. • ;•.-.. ·•11• 1 -..,,:-· I · ' ... . \ Hz: � ) .,...,; "" • .. ,...... ,,. r; , � -- <' . --�"' .-i . ,-; I - ...... , · ,. ' \ w . .• r....::: . :... . - - r.: ·.- l ·''• • I -:: 1 ffi'-' ·w:- . .,,,..,1�; , . � _ _ . S'.'.'f:�? ii.'.�E _i _:t""- 1i- �oe . f ,- \ � - - , 1 '1 - . • - ""'\ I' •• ' ·-�)� ._: l . . I �.I.:.:.? 11. :... 11. ·1· - H:z: . 1 , ,. ·,. .... I e ' I J\. • __t..' t� (._ -\ ...,,_ ;;:? C.-;�.:T.. - - Ht !I . : ...... , 1 I - L • . . �:�er.::�.·-· ,.. ?. - -I ) I • . !:.: ...... :... .-.� 1- ...... -._... ..; ·· . ___..�� .'�' .'. ?, - .... o .__,.__,..;;-_...._ ..._...._.��-�--..._. ·- _ _ - ... ,._.) . � i: ().) . o 1 0 =...... ---.-·" . ,,..o-1119 ...... '':' • �. ���·------.. __!/1, _ ��·---�-"--J:�-· ' ·...... · . __::�--.. . . • .. # ' . . • • . • . • ; :: . 'i' � , . •· I • y ·> : . _ : ;,::. : _ : . . . . - • . :·< · :·; .. . : • • • . ..: . . • ...... 'I'i . . I ... I: · : I . . . . I.... ·L . . � . • . �: ·I : : !. : . :• • : I . . .. . /;_: . '.t : l.. i �:';;,. · j .. ; i:;�\t_�\ �.. I . . . • . ··: . . �: i ..• . I ! � I : · � .. : I i .. : -: . . I . ,;:'.··:[�;. 2{:tl . • I ' . .· . . ·• ; • ....I• ' . · ·. . .. ·. . . I . . ' . ; . . · ! q-•; -�"- l · � I . � �. . . . ; . . : . I i . � ·. ·' 1· : . . "' .. ' . · •. • ' ·• . . . I . . � �.: i . � . . . .• ; . �- · · . ! - : I : , . I I . .. . · · . · 1 . • · . . f : · ' . • :� · :-· . ·:· : . . . ; . ·· I . l• . , .. · . - . : . . i I. i' : .• • .. •. .! .: i . ' . . • ·. . ! · , .;o f• . I · . . i ...... - . ·� : , �: . . . � . • ! · . . I l . : . I . [ r. . ..-.•• • t · • . . · .. . · . .. ; . . . j :. : . . ' rf' . � :.-. l· ::� ? - ; · - • .. • • • .. . t . � . · I'! : l • . f i l I · ' i. • .. 'I . 1 ; I J ...... �'j l'r/).· ; · � . ..f' ��· ��� . �J �., JI� :') .r . i.. . . .;I . . n . • · · 1 I · -r i i --- 1 __ II • I i � 2.C to , 9 3.0 2.0 l.O 0 NMR of 10. _ NMR SPECTRUM 9. spectrum PECTRUM spectrum of 12 after irradiation for 4 after irradiation for !! �n 24 in the presence of o2 the presence of o2 hours hours( 1 .26 (l.� , s , CH3 and 1.26 , , s , CHJ ). s , CH3) . .::: '° START •• PRCCEDURE OPTI ONS (NAIN) 1o DECLARE Al9S9} FLOAT1 CT!999 ) FLOAT, CKC 999 ) FLOAT, R{999) FLOAT, • : l !-.!-� c ( 9 9 9 } C :-:.':i R A C T E R { t� ) ., . LCC?.. DO L=l TO 41& G�T EDI7( Uh\;.�E( U 00 I= l TO J.3) }{13A C4) ),. GET ECIT{i�1AlHF(l},F CS13) ),. T=O ,. ?UT ? .4 GE L ! ST( ' PH OT ODE SUr=iJRI ZAT I ON OF MO NOTH I ONE IN 2-PROPANOL 1)7• ? UT ED I T\ NAf·' E ) {SK 1 P ( 1 ) , 13A { 4) ) , • ?i,;T EDIT( t THE CONCENTRAT ION Of THc SOLUTION IS 1,Al/9.. 65, ' M• )(S KI P 1 • i� : F ( l 0 t 7 ) 1 .!:i. ) , , . . ? U T · SK IP LlST{ • T A CT CK K' ),. ?�T SKI? LIST( ' CHR) (M) (HR- 1)• ),. ED IT{ f,Al,Al/9o65}{SK!P(2l,X( 2) �F{(M)3) ,X(5) .F( 5�3),X(5),F( 5 13) ),. PUT :.. { 1 )=/-1.1,. = _,_ 1 • · CJ C ,j = Z T 0 N BY l , • T T 12 GET EDIT(A(J) ) {F{5,3} ),. CK (J) =(A( ll-A( J)) / 9.65 , . • R ( J ) = 1 / T �L JG (A ( 1 ) I A ( J) ) t EDI TCT,AtJ},A(J)/9o 6 51C K (J) ,R(J)) (SKIP1X(2) ,F(3J1XC5),FC5 ,3), P�T . , X ·. '/. t 5} 1 = ( 5 , 3) , X ( 5) , f { 5 , 3 ) ( 5 > , F ( D , S ) ) , • EN O, • c \� J LOO? to • • F 1 : .; I S H E ;·� D· S TAR T , • ·)r0:3ra·-n to cal�:...< l�.ts t�9 �� 1 11et tc . ? �01?�\ · .: c�·l!y.Ater. data for a first �rder reac �ion. � 51 REFERENCES 1. G. Calvert and N• Pitts, Jr. , "Photochemistry", John Wiley J. J. Sons, Inc. , New York, 1966. -- & 2. N. J. Turro, "Molecular Photochemistry", A. Benjamin, Inc. , New York, 1965. w. . Ellis a.nd A. A. Wells, "The Chemical Action of Ultraviolet ) c.Ray s", Reinhold, New York, 1941 . P. Borrell, Reports Chem. Soc, (London), 60, 62 (1963 Ann . ). 4. N\NJ Ohno, Y. Ohnishi, M. Fukuyama, and G. Tsuchihashi, J. S. Chem.A. Soc,, 90, 7038 (1968). Am, ANIH Katritzky, R. Mayer, Morgenstern and M, J. Sewell, 6. A. Soc., 5953 (1965J.). J. Chem. Worman and P.a. Nichols, Midwest Regional ACS Meeting, ?. J. J. City, Mo. , Oct. 1969, Abs . No, 40J. Kansas 8. Elam and H. E, Davis, J. Org, Chem. , 32, 1562 (1967 . E, U. ) MN" 9. Mayer, J, Morgenstern and I. Fabian, Angew. Chem,, 76 , R. 157 (1964) . � Photochemistry", Reinhold D. Neckers, "Mee istic Organic 10, Publc.ishi ng Co., 1967. Turro, G.W. Byers, P.A. Leermakers, J. Chem, Soc., 11 K. J. 55 Am. � 9 (1964) . 12. N, Turro, P. A. Leermakers, H. R. Wilson, D. Neckers, J. �. Byers, and G. F. Vesley, Chem. Soc., !t(, 2613 (1965) . G . w. J. Am. Zwanenburg, A. Wag aar, and Strating, Tet. Letters, en J, 1), B. 4683 (1970) . �.. 14. R. H. Schlessinger, and A. G. Schultz, Tet. Letters, 4513 (1969). orman and E. Schmidt, Midwest Regional ACS Meeting, Lincoln W · 1 J J 5, lf�br. aska, , 1970, Abs. No. 542. Oct. l6. P. Nichols, M. Thesis, South Dakota State University, c . s. Sou Dakota, J e 1970. Brookings, th un , 52 17. A. Seidell, ..So lubilities of Inorganic and Metal Organic Com pounds", Fourth Edition, D. Van Nostrand Co. Inc. , New York, 1965. 18. A. Weissberger, "Technique of Organic Chemistry" , Vol . XIV, 102 (1969) • .-. 19. Foote, Account Chemical Research, 104· (1968). c . s. 2z, 20. Foote, Wexler, Ando, Higgins , J, Am, Chem, c. s. s. w. R. Soc,, 90, 975 (1968) , -� . K, Gollnick and G. O, Schenck "1,4 Cycload.dition Reaction•• , 21. J. Hamer, Ed , , Academic Press Inc. , New York, 1967, 22, Bubbl ing nitrogen gas through the solution to remove oxygen , 2), Personal contact with Westinghouse Electric Corporation, R, L. Allen, Field Sales Engineer, March 29, 1971. 24, R. Peterson, M. Kal.bog and Irving, Ann. N. Y, c . s. c . s. Acad, Sci,, 171, 133 (1970), NINW