Erratum: Experimental Evidence for p Ka-Driven Asynchronicity in C-H Activation by a Terminal Co(III)-Oxo Complex (Journal of the American Chemical Society (2019) 141:9 (4051?4062) DOI: 10.1021/jacs.8b13490)

Article abstract of DOI:10.1021/jacs.0c02031

It has been brought to our attention that our previous analysis of kinetic data for C-H activation was incomplete. For the reaction of PhB(^tBuIm)₃Co^IIIO (3) with various substrates, the observed rate constants, k_obs, were originally determined by plotting the natural log of the UV-vis absorbance at 470 nm at time t (A_t) divided by the initial absorbance (A₀) versus time in seconds to give k_obs as the slope of the linear fit of the data. However, this method implicitly assumes that the absorbance at infinite time, A_inf, is equal to 0. This is not true for these reactions due to absorbances from the reaction products, resulting in an underestimation of the true k_obs values for each substrate. In order to obtain more accurate kobs values, the data were reanalyzed by fitting the absorbance versus time data at 470 nm to an exponential function, A_t = A_inf + (A₀ - A_inf) e^-kt. This method explicitly accounts for A_inf in the fitting parameters, providing more accurate values for the k_obs for each substrate. For the Eyring analysis of the reaction between 3 and 9,10-dihydroanthracene, the noise and subsequent error in the measurements precluded good exponential fits of the variable-temperature data. Therefore, these data were analyzed by finding k_obs as the slope of the linear fit of a plot of ln((A_t - A_inf)/(A₀ - A_inf)) versus t in seconds, where A_inf was estimated from reactions carried out in a cuvette at room temperature. These new analyses result in the following corrections to the original Article.

Full text of DOI:10.1021/jacs.0c02031

pubs.acs.org/JACS
Addition/Correction
Correction to “Experimental Evidence for pKa‑Driven Asynchronicity
in C−H Activation by a Terminal Co(III)−Oxo Complex”
McKenna K. Goetz and John S. Anderson*
J. Am. Chem. Soc. 2019, 141 (9), 4051−4062. DOI: 10.1021/jacs.8b13490
Cite This: https://dx.doi.org/10.1021/jacs.0c02031
Read Online
sı
*
Metrics & More
Article Recommendations
Supporting Information
ACCESS
t has been brought to our attention that our previous
Ianalysis of kinetic data for C−H activation was incomplete.
Figure 1. UV−vis spectra of the reaction between 3 (dark red trace)
and 10 equiv of DHA to produce 1 and anthracene (purple trace).
Gray traces indicate 1 min time points. Inset: Pseudo-first-order
kinetic analysis of the reaction monitored at 470 nm.
For the reaction of PhB(tBuIm)3CoIIIO (3) with various
substrates, the observed rate constants, kobs, were originally
determined by plotting the natural log of the UV−vis
absorbance at 470 nm at time t (At) divided by the initial
absorbance (A0) versus time in seconds to give kobs as the slope
of the linear fit of the data. However, this method implicitly
assumes that the absorbance at infinite time, Ainf, is equal to 0.
This is not true for these reactions due to absorbances from
the reaction products, resulting in an underestimation of the
true kobs values for each substrate. In order to obtain more
accurate kobs values, the data were reanalyzed by fitting the
absorbance versus time data at 470 nm to an exponential
function, At = Ainf + (A0 − Ainf) e−kt. This method explicitly
accounts for Ainf in the fitting parameters, providing more
accurate values for the kobs for each substrate. For the Eyring
analysis of the reaction between 3 and 9,10-dihydroanthracene,
the noise and subsequent error in the measurements precluded
good exponential fits of the variable-temperature data.
Therefore, these data were analyzed by finding kobs as the
slope of the linear fit of a plot of ln((At − Ainf)/(A0 − Ainf))
versus t in seconds, where Ainf was estimated from reactions
carried out in a cuvette at room temperature. These new
Figure 2. Plots of log(kobs) vs (A) BDEC−H of substrate and (B) pKa
of substrate. Each kobs value is that for the reaction of 3 with 10 equiv
of substrate either determined directly or from the k2 value (see
Experimental Section and Supporting Information). Linear fit in (B):
log(kobs) = −0.18pKa + 2.1, R2 = 0.65.
analyses result in the following corrections to the original
Article:
https://dx.doi.org/10.1021/jacs.0c02031
J. Am. Chem. Soc. XXXX, XXX, XXX−XXX
© XXXX American Chemical Society
A

Journal of the American Chemical Society
pubs.acs.org/JACS
Addition/Correction
and the fits to these data were qualitatively poor, suggesting
that caution must be employed in quantitatively interpreting
data for this substrate. Nevertheless, the data were fit to an
exponential to maintain consistency between different
substrates.
Page 4059. In the Experimental Section under the
subsection Procedure for Kinetic Studies, the text originally
read: “To determine the observed rate kobs values, the data
were analyzed by plotting the natural log of the absorbance at
470 nm at time t divided by the initial absorbance versus time
in seconds to give kobs as the slope of the linear fit of the data.
For diphenylmethane, this plot was generated using the
absorbance at 556 nm due to a convoluting absorbance at 470
nm from the radical product generated.” This text should be
replaced with the following:
“To determine the observed rate kobs values, the data were
analyzed by plotting the absorbance at 470 nm at time t versus
time in seconds and fitting the data to an exponential function,
At = Ainf + (A0 − Ainf) e−kt, where Ainf is the absorbance at
infinite time, A0 is the initial absorbance, and k is the observed
rate constant, kobs. For diphenylmethane, this plot was
generated using the absorbance at 556 nm due to a
convoluting absorbance at 470 nm upon injection of
substrate.”
Figure 3. Hammett substituent plot for the reaction of 3 with 9-(4-X-
phenyl)-9H-fluorenes. The red line shows the linear fit of the data: ρ
= 0.87(3), R2 = 0.996.
Table of Contents. The log(kobs) vs substrate pKa plot has
been updated with the more accurately determined kobs values.
The corrected graphic is shown here:
Page 4059. In the Experimental Section under the
subsection Determination of Activation Parameters for the
Reaction between 3 and DHA, the text originally read: “To
determine the observed rate kobs values, the data were analyzed
by plotting the natural log of the absorbance at 470 nm at time
t divided by the initial absorbance versus time in seconds to
give kobs as the slope of the linear fit of the data.” This text
should be replaced with the following:
“To determine the observed rate kobs values, the data were
analyzed by plotting ln((At − Ainf)/(A0 − Ainf)) (where Ainf
was estimated from reactions carried out in a cuvette at room
temperature) versus time in seconds to give kobs as the slope of
the linear fit of the data.”
Supporting Information. Figures S3, S5, S8−S10, S12, S14−
S16, S18, and S21−S24 have been replaced with new
representative exponential fits. Figures S4, S11, S13, S17,
S20, and S29 have been updated accordingly. Figure S6 has
been replaced with the new fits for the variable-temperature
Pages 4053−4055. The more accurately determined kobs
values have been changed in Table 1, Figure 1, Table 2, Figure
2, Table 3, and Figure 3. The updated tables, figures, and
captions are given here. Any values from these tables, figures,
and captions mentioned explicitly in the text should be those
from these updated tables, figures, and captions. We would also
like to note that exponential fits of the data for diphenyl-
methane were sensitive to the inclusion of initial time points,
Table 1. Thermodynamic Data for Selected Transition Metal Oxo/Hydroxo Complexes and Their Reactivity Parameters with
DHA
ΔH⧧
ΔS⧧
KIE
(kH/kD)
pKa
b
E0 (V vs
c
BDFEO−H
(kcal/mol)
a
a
a
complex
(kcal/mol)
(e.u.)
k2 (M−1 s−1
)
(DMSO)
Fc/Fc+)
ref
d
e
PhB(tBuIm)3CoIIIO
[(H3 buea)FeIVO]−
13(2)
n.r.
5(1)
14(2)
n.r.
n.r.
5.4(2)
n.r.
−20(6)
n.r.
−49(4)
−14(6)
n.r.
n.r.
−30(2)
n.r.
0.0584(8)
n.r.
0.026(2)
0.48(4)
0.14
1.8(5)× 10−5
186
9.2(6)
n.r.
6.8
2.6
10
n.r.
29
35(5)
20
∼15
11
15
28.3
n.r.
∼11
∼18
<−2
n.r.
−0.23
0.036
−0.11
−1.51
n.r.
−0.33
−0.076
>2.2
84.6
87
89
this work
35
27
27
19
17
20
36, 37
38
e
[(H3 buea)MnIVO]−
e
[(H3 buea)MnIIIO]2−
77
f
[FeIVO(TMC)(MeCN)]2+
84(1)
∼80
90(3)
84.8
n.r.
g
(Cz)MnVO
h
LCuIIIOH
[RuIVO(bpy)2 py]2+
125
13(2)
i
FeIVO(TPFPP)
n.r.
n.r.
n.r.
a
b
Values for reaction with DHA at room temperature. pKa value for Mn+−O/Mn+−OH adjusted using the correlation between pKa values in
c
d
−
DMSO, MeCN, THF, and H2O as necessary. E0 for Mn+−OH/M(n‑1)+−OH adjusted versus Fc/Fc+ as necessary. PhB(tBuIm)3 = tris(1-tert-
e
f
butylimidazol-2-ylidene)phenylborate. H3 buea3− = tris[(N3-tert-butylureayl)-N-ethylene]aminato. TMC = 1,4,8,11-tetramethyl-1,4,8,11-
g
h
tetraazacyclotetradecane. Cz3− = octakis(para-tert-butylphenyl)corrolazinato. L2− = N,N′-bis(2,6-diisopropylphenyl)-2,6-pyridinedicarboxamide.
i
TPFPP2− = meso-tetrakis(pentafluorophenyl)porphinato. Entries depicting n.r. indicate values not reported to the best of our knowledge. See
original Article for references.
B
https://dx.doi.org/10.1021/jacs.0c02031
J. Am. Chem. Soc. XXXX, XXX, XXX−XXX

Journal of the American Chemical Society
pubs.acs.org/JACS
Addition/Correction
Table 2. Kinetic Data for the Reaction of 3 with Various C−H Substrates
a
b
c
substrate
kobs (10−4 s−1
)
k2 (10−2 M−1 s−1
)
KIE (kH/kD)
pKa (DMSO)
BDEC−H (kcal/mol)
d
9,10-dihydroanthracene
xanthene
9.2(4)
14.1(8)
1.0(3)
1.5(4)
0.60(7)
5.84(8)
n.d.
n.d.
1.2(4)
0.27(2)
9.2(6)
n.d.
n.d.
n.d.
n.d.
30.1
30.0
25.8
32.3
35
76.3
75
77
84.5
74.3
1,1,3,3-tetraphenylpropene
diphenylmethane
d
1,3-cyclohexadiene
9-X-9H-fluorene
X = H
X = Bu
X = Ph
95(3)
11(3)
3700(500)
61(4)
n.d.
n.d.
3.1(1)
n.d.
n.d.
22.6
24.4
17.9
82
79.9
74
t
a
b
Determined using 10 equiv of substrate per equiv of Co complex either directly or from the k2 value. Data taken from the Bordwell pKa table.43
c
d
Data taken from the CRC’s Handbook of Bond Dissociation Energies.44 Rates corrected for stoichiometry. Entries depicting n.d. indicate values
that were not determined. See original Article for references.
Table 3. Rates for Substrates Used in Hammett Analyses
a
b
kobs (10−2 s−1
)
σp
−
substrate
9-(4-X-phenyl)-9H-fluorene
X = OMe
X = Me
X = H
22(3)
28(4)
37(5)
−0.26
−0.17
0.00
CF3
140(40)
0.65
3-X-xanthene
X = Me
X = H
0.11(2)
0.141(8)
−0.17
0.00
a
b
Values obtained using 10 equiv of substrate. Hammett parameters
obtained from Hansch, Leo, and Taft.45 See original Article for
references.
kinetic data for the reaction of 3 with DHA, and Figure S7 has
been updated accordingly.
The conclusions of the paper remain unchanged after the re-
evaluation of the kinetic data, and indeed a slightly better
correlation between pKa and rate constants is observed.
ASSOCIATED CONTENT
* Supporting Information
The Supporting Information is available free of charge at
https://pubs.acs.org/doi/10.1021/jacs.0c02031.
■
sı
Supplementary derivations, figures, tables, and schemes
(updated) (PDF)
ACKNOWLEDGMENTS
■
We thank Professor David M. Stanbury of Auburn University
for bringing to our attention our incomplete treatment of the
kinetic data and for his suggestions and insight regarding our
updated analysis.
C
https://dx.doi.org/10.1021/jacs.0c02031
J. Am. Chem. Soc. XXXX, XXX, XXX−XXX