The Chemistry of Acid Rain - American Chemical Society

Chapter 11

Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on May 28, 2018 | https://pubs.acs.org Publication Date: September 3, 1987 | doi: 10.1021/bk-1987-0349.ch011

Direct Kinetic and Mechanistic Study of the OH-Dimethyl Sulfide Reaction Under Atmospheric Conditions A. J. Hynes and P. H. Wine Molecular Sciences Branch, Georgia Tech Research Institute, Georgia Institute of Technology, Atlanta, GA 30332 A pulsed l a s e r p h o t o l y s i s - p u l s e d l a s e r induced f l u o r e s cence t e c h n i q u e was employed to study the OH + CH3SCH3 r e a c t i o n in N2, air, and O2 b u f f e r g a s e s . Complex kinetics were o b s e r v e d in the p r e s e n c e o f O2. A four s t e p mechanism i n v o l v i n g hydrogen a b s t r a c t i o n , reversible a d d i t i o n to the sulfur atom, and s c a v e n g i n g o f the ( t h e r m a l i z e d ) adduct by O2 is r e q u i r e d to e x p l a i n all experimental observations. I n one atmosphere o f air, the effective b i m o l e c u l a r r a t e constant decreases m o n o t o n i c a l l y from 1.58 x 10 to 5.2 x 10 cm3 molecule-1 -1 o v e r the l o w e r t r o p o s p h e r i c t e m p e r a t u r e range 250-310K. Over the same t e m p e r a t u r e range the b r a n c h i n g ratio for h y d r o g e n a b s t r a c t i o n i n c r e a s e s m o n o t o n i c a l l y from 0.24 to 0 . 8 7 . -11

-12

S

On a g l o b a l s c a l e , n a t u r a l e m i s s i o n s o f reduced s u l f u r compounds account f o r about 50% o f the t o t a l s u l f u r f l u x i n t o the atmosphere (1-3). Hence, i t i s i m p o r t a n t to u n d e r s t a n d the n a t u r a l s u l f u r c y c l e i n o r d e r t o e s t a b l i s h a "base l i n e " f o r a s s e s s i n g the s i g n i f i c a n c e o f a n t h r o p o g e n i c p e r t u r b a t i o n s ( p r i m a r i l y SO2 e m i s s i o n s ) . DimethyIsulf i d e (DMS) i s the predominant r e d u c e d s u l f u r compound e n t e r i n g t h e atmosphere from t h e oceans ( 4 - 9 ) , and DMS o x i d a t i o n r e p r e s e n t s a major g l o b a l s o u r c e o f S ( V I ) . The a t m o s p h e r i c o x i d a t i o n o f DMS can be i n i t i a t e d by r e a c t i o n w i t h e i t h e r OH o r NO3. I n marine e n v i r o n m e n t s , however, NO3 l e v e l s a r e t y p i c a l l y v e r y low and DMS i s d e s t r o y e d p r i m a r i l y by OH:

OH +

->

CH3SCH2 + H 0

(la)

->

CH S(OH)CH

(lb)

2

CH3SCH3

3

3

0097-6156/87/0349-0133$06.00/0 © 1987 American Chemical Society

Johnson et al.; The Chemistry of Acid Rain ACS Symposium Series; American Chemical Society: Washington, DC, 1987.

THE CHEMISTRY OF ACID RAIN


134

A number o f k i n e t i c s s t u d i e s of R e a c t i o n 1 have been r e p o r t e d (10-17). I n a d d i t i o n , s e v e r a l s t e a d y s t a t e photοlys i s - e n d p r o d u c t a n a l y s i s s t u d i e s have r e c e n t l y been r e p o r t e d where c o n c l u s i o n s were drawn c o n c e r n i n g the r e l a t i v e importance o f h y d r o g e n a b s t r a c t i o n and a d d i t i o n t o the s u l f u r atom as r e a c t i o n pathways (18-20). Despite the r a t h e r l a r g e d a t a base, n e i t h e r t h e r a t e c o n s t a n t nor t h e b r a n c h i n g r a t i o f o r R e a c t i o n 1 i s w e l l d e f i n e d . V a l u e s f o r k i have been measured d i r e c t l y u s i n g b o t h f l a s h p h o t o l y s i s (10,11,13,17) and d i s charge f l o w (14,16) t e c h n i q u e s , w i t h r e p o r t e d 298K r a t e c o n s t a n t s r a n g i n g from 3.2 t o 9.8 χ 10~12cm3molecule~l-s~l- and r e p o r t e d a c t i v a t i o n e n e r g i e s r a n g i n g from -352 to +274 c a l m o l e " . A l l direct measurements were c a r r i e d out i n the absence o f t h e p o t e n t i a l l y r e a c t i v e gas 02· Two c o m p e t i t i v e k i n e t i c s s t u d i e s (12,15), b o t h of w h i c h employed one atmosphere o f a i r as t h e b u f f e r gas, r e p o r t 298K r a t e c o n s t a n t s i n agreement w i t h t h e h i g h e r v a l u e s r e p o r t e d i n t h e direct studies. W h i l e t h e r e seems t o be g e n e r a l agreement t h a t the b r a n c h i n g r a t i o f o r Channel l a i s s i g n i f i c a n t , the c o n t r i b u t i o n from Channel l b remains p o o r l y d e f i n e d . 1

We have employed a p u l s e d l a s e r p h o t o l y s i s - p u l s e d l a s e r i n d u c e d f l u o r e s c e n c e t e c h n i q u e t o c a r r y o u t d i r e c t , r e a l time s t u d i e s o f OH r e a c t i o n s w i t h DMS and DMS-dfc i n N 2 , a i r , and O 2 b u f f e r gases. Both temperature and p r e s s u r e dependencies have been i n v e s t i gated. We f i n d t h a t the o b s e r v e d r a t e c o n s t a n t ( k b = d[0H]/[0H] [DMS]dt) depends on t h e O 2 c o n c e n t r a t i o n . Our r e s u l t s a r e c o n s i s t e n t w i t h a mechanism w h i c h i n c l u d e s an a b s t r a c t i o n r o u t e , a r e v e r s i b l e a d d i t i o n r o u t e , and an adduct + O 2 r e a c t i o n w h i c h competes w i t h adduct d e c o m p o s i t i o n under a t m o s p h e r i c c o n d i t i o n s . Q

s

Experimental A s c h e m a t i c o f t h e apparatus i s shown i n F i g u r e 1. OH was produced by 248 nm ( o r 266 nm i n some e x p e r i m e n t s ) p u l s e d l a s e r p h o t o l y s i s o f H 2 O 2 and d e t e c t e d by o b s e r v i n g f l u o r e s c e n c e e x c i t e d by a p u l s e d t u n a b l e dye l a s e r . F l u o r e s c e n c e was e x c i t e d i n t h e 0 Η ( Α 2 Σ - X^ir) 0-1 band a t 282 nm and d e t e c t e d i n the 0-0 and 1-1 bands a t 309+5 nm. K i n e t i c d a t a was o b t a i n e d by e l e c t r o n i c a l l y v a r y i n g t h e time d e l a y between t h e p h o t o l y s i s l a s e r and the p r o b e l a s e r . S u l f i d e concentra t i o n s were measured i n s i t u i n t h e slow f l o w system by UV photometry a t 228.8 nm. +

Results A l l experiments were c a r r i e d o u t under p s e u d o - f i r s t o r d e r c o n d i t i o n s w i t h DMS i n l a r g e excess o v e r OH. E x p o n e n t i a l OH decays were ob s e r v e d under a l l e x p e r i m e n t a l c o n d i t i o n s i n v e s t i g a t e d . P l o t s o f k ( t h e p s e u d o - f i r s t o r d e r OH decay r a t e ) v e r s u s DMS c o n c e n t r a t i o n were linear. V a l u e s f o r k b were o b t a i n e d from l i n e a r l e a s t squares d e t e r m i n a t i o n s of t h e s l o p e s o f k v e r s u s [DMS] p l o t s . Measured values f o r k ^ as a f u n c t i o n o f temperature, p r e s s u r e , and O 2 con c e n t r a t i o n a r e summarized i n T a b l e I . Important o b s e r v a t i o n s c o n c e r n i n g t h e d a t a r e p o r t e d i n T a b l e I a r e summarized below 1. I n the absence o f 0 , DMS r e a c t s s i g n i f i c a n t l y more r a p i d l y w i t h OH t h a n does DMS-dfc. T h i s s u g g e s t s t h a t under t h e s e experimen t a l c o n d i t i o n s (no O 2 ) h y d r o g e n a b s t r a c t i o n i s t h e dominant r e a c t i o n !

0

s

f

Q

s

2



11.

HYNES AND WINE

The OH and Dimethyl Sulfide Reaction

135

F i g u r e 1. Schematic o f t h e a p p a r a t u s . A C - a b s o r p t i o n c e l l , BPFbandpass f i l t e r , CdL-cadmium lamp, C M - c a p a c i t a n c e manometer, IDf r e q u e n c y d o u b l e r , DG-three c h a n n e l d e l a y g e n e r a t o r , DC-dye l a s e r , EM-emergy m o n i t o r , GI-gas i n l e t , HS-harmonic s e p a r a t o r , HV-high v o l t a g e , ΡA-picoammeter, PD-photodiode, PM-photomultip l i e r , PL-photolysis l a s e r , RC-reaction c e l l , SA-signal a v e r a g e r , T - c h r o t t l e , YL-Nd:YAG l a s e r , 7-54F-Corning 7-54 g l a s s filter.


136

THE CHEMISTRY OF ACID RAIN

Table I.

Observed B i m o l e c u l a r Rate C o n s t a n t s as a F u n c t i o n o f Temperature, P r e s s u r e , and 0 Concentration 9

Sulfide

T(K)

P(Torr)

M

Range o f .. k (s ) 1

( a )

k , +2a obs (10- cm molecule^ls" ) -

12

3


1

CH SCH 3

CD SCD 3

3

3

+

1.7

9.53

+

0.28

160-•13700

4.80

+

0.11

53-•7500

4.75

+

0.15

262

700

air

498- •24900

1?.5

279

700

air

372- •24200

298

40

298

500

N

2

SF

6

298

50

air

151-•8610

4.68

+

0.08

298

130

air

1960- •21800

5.04

+

0.14

298

340

air

310-•28900

5.18

0.34

298

590

air

596- •56100

5.80

+

298

750

air

1850- •65700

6.28

+

0.10

321

700

air

420-•22300

5.43

+

0.30

261

700

air

1080- •50500

11.6

+

1.1

854- •48500

13.5

+

1.2 2.0

266

700

275

700

276 287 287

700

298

450

298

100

°2

0.16

606-•54200

11.9

+

700

°2 air

1650- •47300

9.63

± 0.63

700

air

777-•20100

5.29

+

0.44

593-•23100

6.99

+

0.53

1520- •18900

1.82

+

0.11

193- •19800

2.10

+

0.15

°2 N

2 air

298

300

air

336-•17300

2.68

+

0.09

298

500

air

804-•11700

2.97

+

0.13

298

700

air

672-•18900

3.40

+

0.13

1290- •21200

6.50

+

0.72

817-•16500

3.02

+

0.18

298

700

317

700

321

700

340

700

340

700

361

700

(a) e r r o r s a r e 2σ and r e p r e s e n t

°2 air °2 air °2 air

0.27

620-•13600

3.72

1030- -11470

2.32

+

0.11

547--7880

2.30

+

0.28

1110- -15200

2.66

cision

only


0.11

11.

HYNES AND

137


WINE

pathway. We have c a r r i e d out c o n v e n t i o n a l FP-RF k i n e t i c s t u d i e s o f OH r e a c t i o n s w i t h a s e r i e s of s u l f i d e s i n argon b u f f e r gas ( 2 1 ) ; r e a c t i v i t y t r e n d s and a c t i v a t i o n e n e r g i e s o b s e r v e d i n t h e s e e x p e r i ments s u p p o r t t h e dominance o f Channel l a when no O 2 i s p r e s e n t . 2. A t 298K, k b i n c r e a s e s as a f u n c t i o n of a i r p r e s s u r e f o r b o t h DMS and DMS-d6 r e a c t i o n s w i t h OH. The s l o p e s o f k b versus ^ a i r pl°ts a r e v i r t u a l l y e q u a l f o r t h e two s u l f i d e s . 3. I n b o t h a i r and O 2 a t 700 T o r r t o t a l p r e s s u r e , k ^ in c r e a s e s d r a m a t i c a l l y w i t h d e c r e a s i n g temperature. A l l experimental o b s e r v a t i o n s are c o n s i s t e n t w i t h the f o l l o w i n g mechanism ( w r i t t e n f o r C H 3 S C H 3 b u t i d e n t i c a l f o r C D 3 S C D 3 ) : 0

s

Q

s


0

OH

+

CH3SCH3

>

CH3SCH2

OH + C H 3 S C H 3 + M CH S(OH)CH

3

+ M

CH S(OH)CH

3

+ 0

3

3

>

H0

(la)

2

CH S(OH)CH 3

+ M

3

(lb)

OH + C H 3 S C H 3

> >

2

+

g

(-lb)

products

(2)

> l o s s by r e a c t i o n w i t h H 2 O 2 and d i f f u s i o n from the d e t e c t o r f i e l d of view

OH

(3)

As mentioned above, i n the absence of O 2 a l l o b s e r v e d OH removal ap p e a r s t o be v i a t h e a b s t r a c t i o n r o u t e , i . e . R e a c t i o n l a . A p p a r e n t l y , R e a c t i o n - l b i s v e r y f a s t compared to the time s c a l e o f our e x p e r i ments. However, the adduct l i f e t i m e must be l o n g enough t h a t i t can be scavenged by O 2 i n c o m p e t i t i o n w i t h d e c o m p o s i t i o n b a c k to r e a c t ants. The d r a m a t i c dependence o f k ^ on temperature i s q u a l i t a t i v e l y c o n s i s t e n t w i t h the above mechanism. The a c t i v a t i o n energy f o r R e a c t i o n - l b i s e x p e c t e d t o be q u i t e l a r g e , s o t h e f r a c t i o n o f adduct m o l e c u l e s scavenged by O 2 can i n c r e a s e d r a m a t i c a l l y o v e r a r e l a t i v e l y s m a l l temperature range. A t h i g h O 2 l e v e l s , t h e adduct can be assumed to be i n s t e a d y state. A p p l y i n g the s t e a d y s t a t e a p p r o x i m a t i o n t o t h e above mechan ism, one o b t a i n s : 0

,

_

obs

s

k, (T) + X C O i k , (T) + k ( T ) } [ 0 j la la lb l_ 1 T

1 + X(T)[0 ]

γ/ \

'

2

M

1

k (T) * 9

=

" k_ (T) lb

We assume t h a t o v e r the l i m i t e d temperature range 260 r a t e c o n s t a n t s can be e x p r e s s e d i n A r r h e n i u s form: = A

k (T) ±

1

exp

//>

τ

;

- 360K, a l l

(-E /RT).

(5)

±

We have t a k e n the 13 r a t e c o n s t a n t s f o r OH + DMS-d5 measured i n 700 T o r r a i r and 700 T o r r 0 ( T a b l e I) and f i t k g ( T , [ 0 D to E q u a t i o n 4 u s i n g a l e a s t squares f i t t i n g c r i t e r i o n . The s u p e r s c r i p t D i n d i c a t e s the C D 3 S C D 3 a n a l o g o f e q u a t i o n s 1-4. V a l u e s f o r k ^ ( T ) were 2

b s

2

a


138

T H E CHEMISTRY OF ACID RAIN

taken from the FP-RF results (21). A j , Α^(Ξ A ^ / A ^ ) and Εχ(Ξ E^-E^ ) were taken as independent variables. By analogy with known activation energies f o r OH addition to C H 3 S H (22), C H 3 S D (22), and C H 3 S S C H 3 (13)» E Ç was fixed at -0.7 kcal/mole. As shown i n Figure 2, equation 4 f i t s the experimental data very well (median residual = 5.3%); we conclude, therefore, that the proposed mechanism does include a l l important reactions. Best f i t parameters are A Ç ^ = 3.04 χ 10~l cm molecule~ls~l, A5 = 5.53 χ 10" cm molecule , and E§/R = 7460K. b

b


2

3

31

3

_1

Implications f o r Atmospheric Chemistry Our results demonstrate that both the e f f e c t i v e rate constant ( k ) and the branching r a t i o (addition versus abstraction) f o r reaction (1) change dramatically as a function of temperature over the lower tropospheric temperature range 250-310K. I t should be be kept i n mind that, f o r purposes of atmospheric modeling, addition followed by decomposition back to OH + C H 3 S C H 3 i s treated as no reaction. The " e f f e c t i v e " addition pathway represents only those adduct molecules which are scavenged by O 2 . A majority of our experiments employed DMS-dg as the s u l f i d e reactant because more information concerning elementary reaction rates could be obtained i n this matter (this aspect of our study i s not discussed i n d e t a i l i n this paper). However, enough experiments were carried out with DMS to demonstrate that, within experimental uncertainty, k values for OH reactions with DMS and DMS-dg d i f f e r only by the difference i n the abstraction rates. The pressure dependence data i n a i r at 298K strongly supports t h i s approximation. Substituting the appropriate Arrhenius parameters into equation 4 leads to the following expression for the temperature dependence of obs 760 Torr a i r (units are cm molecule^s"!) : o b g

o b g

k

f

o

r

t

h

e 0

H

+

D

M

S

r

e

a

c

t

i

o

n

i

n

3

1Q

k

=

°

1Q

Texp(-234/T) +8.64x10 exp(7230/T) + 2.68x10 exp(7810/T)

b S

n

1 . 0 4 x l 0 T + 88.1exp(7460/T) (6)

Values f o r k at ten degree i n t e r v a l s have been calculated from equation 6, as have branching ratios f o r abstraction ( B ) and addition ( B ^ ) . The branching ratios were calculated from the relationships Q b g

a b s

a

B

k

/ k

12

abs - l a o b s " 9. 6 x l O - e x p ( - 2 3 4 / T ) / ^ ^

Β ΑΆ = 1 - Β , add abs The results are tabulated i n Table I I .


(7)

(8)

139


HYNES AND WINE

2 op

1

1

1

I

I

1

1

I

I

Γ


~Ο····02

IL

I

2.6

3.0

3.4

I

=1

3.8

1000/T0O F i g u r e 2. R e s u l t s o b t a i n e d from u s i n g e q u a t i o n 4 t o s i m u l a t e t h e dependence o f k b on L O 2 ] l t e m p e r a t u r e f o r t h e OH + CD3SCD3 reaction. A l l b i m o l e c u l a r r a t e c o n s t a n t s were measured at a t o t a l p r e s s u r e o f 700 T o r r . The b e s t f i t parameters A Ç , A^, and E^/R a r e g i v e n i n t h e t e x t . E r r o r b a r s a r e 2σ, p r e c i s i o n only. a

0

n

(

s

B


140

THE CHEMISTRY OF ACID RAIN Table I I .


τ (Κ)

10^k

Values

f o r Κ , , Β , , and Β ,, obs abs add

, (cm^molecule "'"s obs

250 260 270 280 290 300 310

B

15.8 14.5 12.5 9.8 7.4 5.9 5.2

abs

B

0.24 0.27 0.32 0.42 0.58 0.75 0.87

add

0.76 0.73 0.68 0.58 0.42 0.25 0.13

Under a t m o s p h e r i c c o n d i t i o n s t h e a b s t r a c t i o n r o u t e i s thought t o r e s u l t i n production o f CH3S + H C 0 v i a the f o l l o w i n g r e a c t i o n sequence ( 1 7 , 2 0 ) : 2

OH + C H S C H 3

CH SCH 3

+ 0

2

CH SCH 0 3

2

2

2

3

—

->

2

4- M

>

+ NO

->

2

3

CH SCH 0 3

2

2

(la)

2

+ M

CH SCH 0 + N 0

(9)

2

(10)

CH S + CH 0 + M

(11)

3

>

CH SCH 0 + M 3

H 0 + CH SCH

2

3

2

The u l t i m a t e f a t e o f C H 3 S i s unknown, a l t h o u g h B a l l a , e t a l . (23) report d i r e c t k i n e t i c evidence that t h i s r a d i c a l reacts very r a p i d l y w i t h NO and N 0 b u t n e g l i g i b l y s l o w l y w i t h 0 . P o s s i b l e r o u t e s f o r the adduct + 0 r e a c t i o n i n c l u d e t h e f o l l o w i n g : 2

2

2

-> C H S C H 3

3

+ H0

(12a)

2

(DMSO)

OH

I

CH SCH 3

3

+ 0

2

-> C H 0 3

2

+ CH S0H

(12b)

3

C H S 0 H i s p r o b a b l y c o n v e r t e d t o C H S 0 H ( m e t h a n e s u l f o n i c a c i d ) by r e a c t i o n w i t h 0 w h i l e t h e a t m o s p h e r i c f a t e o f DMSO i s u n c l e a r . DMSO has a v e r y low v a p o r p r e s s u r e and may be r a p i d l y removed v i a heterogeneous processes. A t 298K o u r r e s u l t s demonstrate t h a t r e a c t i o n 1 i n one atmos p h e r e o f a i r p r o c e e d s 70% v i a a b s t r a c t i o n and 30% v i a ( i r r e v e r s i b l e ) addition. P h o t o o x i d a t i o n s t u d i e s have been r e p o r t e d by N i k i , e t a l . (18) and Hatakeyama and Akimoto (19), where 298K S 0 y i e l d s from OH i n i t i a t e d o x i d a t i o n o f C H 3 S C H 3 were r e p o r t e d t o b e 22% and 21%, respectively. L a r g e y i e l d s o f m e t h a n e s u l f o n i c a c i d were o b s e r v e d i n both studies. At present, there i s i n s u f f i c i e n t information to a l l o w S 0 p r o d u c t i o n t o be a s s o c i a t e d w i t h e i t h e r t h e a b s t r a c t i o n 3

3

3

2

2

2


11.

HYNES AND WINE


141

r o u t e o r the a d d i t i o n r o u t e . However, i t s h o u l d be n o t e d t h a t o u r r e s u l t s s u g g e s t t h a t a b s t r a c t i o n i s the dominant r e a c t i o n pathway f o r Τ > 300K w h i l e a d d i t i o n i s the dominant pathway f o r Τ < 270K. Hence, temperature dependent p r o d u c t a n a l y s i s s t u d i e s s h o u l d shed some l i g h t on t h e d e t a i l e d pathways f o r S 0 and CH^SO^H p r o d u c t i o n . 2


Acknowledgment T h i s work was s u p p o r t e d by t h e N a t i o n a l S c i e n c e g r a n t n o . ATM-82-17232.

Foundation through

Literature Cited 1. 2. 3. 4.

Cullis, D. F.; Hirschler, M. M. Atmos. Environ. 1980, 14, 1263. Moller, D. Atmos. Environ. 1984, 18, 19. Moller, D. Atmos. Environ. 1984, 18, 29. Barnard W. R.; Andreae, M. O.; Watkins, W. E.; Bingemer, H; Georgii, H.-W. J. Geophys. Res. 1982, 87, 8787. 5. Andreae, M. O.; Barnard, W. R.; Amnions, J . M. Ecol. Bull. 1983, 35, 167. 6. Andreae, M. O.; Raemdonck, H. Science 1983, 221, 744. 7. Cline, J . D.; Bates, T. S. Geophys. Res. Lett. 1983, 10, 949. 8. Turner, S. M.; Liss, P. S. J. Atmos. Chem. 1985, 2, 223. 9. Andreae, M. O.; Ferek, R. J.; Bermond, F.; Byrd, K. P.; Engstrom, R. T.; Hardin, S.; Houmere, P. D.; Le Marres, F.; Raemdonck, H.; Chatfield, R. B. J. Geophys. Res. 1985, 90, 12891. 10. Atkinson, R.; Perry, R. Α.; Pitts, Jr., J . Ν. Chem. Phys. Lett. 1978, 54, 14. 11. Kurylo, M. J. Chem. Phys. Lett. 1978, 58, 233. 12. Cox, R. Α.; Sheppard, D. Nature 1980, 289, 330. 13. Wine, P. H.; Kreutter, Ν. M.; Gump, C. Α.; Ravishankara, Α. R. J. Phys. Chem. 1981, 85, 2660. 14. MacLeod, H.; Poulet, G.; LeBras, G. J . Chem Phys. 1983, 80, 287. 15. Atkinson, R.; Pitts, Jr., J. N.; Aschmann, S. M. J. Phys. Chem. 1984, 88, 1584. 16. Martin, D.; Jourdain, J . L . ; LeBras, G. Int. J. Chem. Kinet. 1985, 17, 1247. 17. Wallington, T. J.; Atkinson, R.; Tuazon, E. C.; Aschmann, S. M. Int. J. Chem. Kinet. 1986, 18, 837. 18. Niki, H.; Maker, P. D.; Savage, C. M.; Breitenbach, L. P. Int. J. Chem. Kinet. 1983, 15, 647. 19. Hatakeyama, S.; Akimoto, H. J. Phys. Chem. 1983, 87, 2387. 20. Grosjean, D. Environ. Sci. Tech. 1984, 18, 460. 21. Hynes, A. J.; Wine, P. H.; Semmes, D. H. J. Phys. Chem. 1986, 90, 4148. 22. Wine, P. H.; Thompson, R. J.; Semmes, D. H. Int. J . Chem. Kinet. 1984, 16, 1623. 23. Balla, R. J.; Nelson, H. H.; McDonald, J. R. Chem. Phys. 1986, 109, 101. RECEIVED June 2, 1987


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