6926 The Journal of Physical Chemistry, Vol. 94, No. 17, 1990
Additions and Corrections
ADDITIONS AND CORRECTIONS 1990, Volume 94
Jens Spanget-Lamen,* Jacek Waluk, and Erik W. Thulstrup: Electronic States of Chrysene. Linear and Magnetic Circular Dichroism and Quantum Chemical Calculations. Page 1803. We regret that an error in sign appeared in the denominator of eq 8. The correct equation is IPi
- PA = cos-,
( ( [ ( K i-
Ky)(Kf-Ky)Jl/2 f [ ( K , - Ki) x (K,- ~ f ) 1 I ~ 2 l / W z- Ky))
The results quoted in the paper were produced with the correct equation and are thus unaffected by this error.
R. S. Mock and E. P. Grimsrud*: Optically Enhanced Electron Capture by p-Benzoquinone and Its Methylated Derivatives. Page 355 1. Electron capture detector (ECD) response enhancements (RE) for pbenzoquinone and three methyl-substituted benzoquinones were reported in Table I over three spectral ranges, called A,, A2, and A3. Due to an experimental oversight, the measurements reported for the A, wavelength region (450-500 nm) are in error. Upon correction of this problem, ( I ) no measurable enhancements of the ECD response to the four quinones are observed in the A, region and (2) the effects of light at other wavelengths are unchanged relative to those originally reported. In view of this, quantitative evaluation of the terms X , and CP, from measurements at A, is not possible, and the discussion of these terms in the paragraph following eq 4 on page 3553 is not valid. Table 1 should be replaced by the table below. Note that the original estimates of uncertainty for kec,Tdeterminations have also been increased by these changes.
TABLE I: Summary of Results O
MQ
DMO
1 . 5 x 10-14 3.5 x 10-13 1 .o
1 .o
TMO 3.5 x 10-12 I .o
1.5300 2,6250 9 x 10-20
I .4 6 X 9 x
2.6 >6
X 10-10
X X
>I x
2.4 X 8 X 1.4 X 2.0 x 10-9
x 104
IO4
>4
10-9
> I x 10-8
7 x 10-19 6 X IO-” 1.8 X IO-* 3.3 x 10-9 > 2 x 104 > I x 10-8
9 x 10-19
6
X
I0-l’
1.3 X >4 x
IO’
> I x 10-8
“ E C coefficients of ground-state quinones at 180 OC. bOptically induced ECD response enhancements measured at A, = 400-500 nm. EAbsorptioncross sections deduced from molar absorptivity coefficients shown in Figure 3. d X 2 is the product k,,T+2 obtained from measuremcnts at X2 and eq 4. ‘Obtained from the ratios of X 2 or X, (whichcvcr is larger) and k,. These are minimum ratios of the rate coefficients since +i values will undoubtedly be less than unity. /Minimum values for EC rate coefficient of triplet-state species, deduced from X 2 or X, (whichever is larger).
