Iron(iii)porphyrin electrocatalyzed enantioselective carbon-chloride bond cleavage of hexachlorocyclohexanes (HCHs): Combined experimental investigation and theoretical calculations

Article abstract of DOI:10.1039/c8dt02510j

Enantioselective electrocatalysis of α-, β-, γ- and δ-hexachlorocyclohexanes (HCHs) by tetrakis-pentafluorophenyl-Fe(iii)porphyrin is described. The first example of the combined use of electrochemical measurements and theoretical calculations to determine the mechanism of the enantioselective C-Cl bond cleavage of the electrocatalysis is reported. The electrochemical measurements demonstrate that the reactivity of the HCHs follows the order γ-HCH > α-HCH > δ-HCH > β-HCH. Steric considerations and a molecular orbital theory approach can be used to rationalize the enantioselective nature of the catalysis based on the ease of approach of each Cl atom to the central Fe(i) ion and a consideration of the nodes on the C-Cl bonds that weaken these bonds in a manner that results in bond cleavage and the formation of an Fe-Cl bond.

Full text of DOI:10.1039/c8dt02510j

View Article Online
View Journal
Dalton
Transactions
Accepted Manuscript
This article can be cited before page numbers have been issued, to do this please use: X. Liang, M. Li, J.
Mack, K. Lobb and W. Zhu, Dalton Trans., 2018, DOI: 10.1039/C8DT02510J.
This is an Accepted Manuscript, which has been through the
Volume 45 Number
1 7 January 2016 Pages 1–398
Royal Society of Chemistry peer review process and has been
accepted for publication.
Dalton
Transactions
Accepted Manuscripts are published online shortly after
An international journal of inorganic chemistry
www.rsc.org/dalton
acceptance, before technical editing, formatting and proof reading.
Using this free service, authors can make their results available
to the community, in citable form, before we publish the edited
article. We will replace this Accepted Manuscript with the edited
and formatted Advance Article as soon as it is available.
You can find more information about Accepted Manuscripts in the
author guidelines.
Please note that technical editing may introduce minor changes
to the text and/or graphics, which may alter content. The journal’s
standard Terms & Conditions and the ethical guidelines, outlined
in our author and reviewer resource centre, still apply. In no
event shall the Royal Society of Chemistry be held responsible
for any errors or omissions in this Accepted Manuscript or any
consequences arising from the use of any information it contains.
ISSN 1477-9226
PAPER
Joseph T. Hupp, Omar K. Farha et al.
Efficient extraction of sulfate from water using
framework
a Zr-metal–organic
rsc.li/dalton

Please do not adjust margins
Dalton Transactions
Page 1 of 8
View Article Online
DOI: 10.1039/C8DT02510J
Dalton Transitions
ARTICLE
Iron(III)Porphyrin Electrocatalyzed Enantioselective Carbon-
Chloride Bond Cleavage of Hexachlorocyclohexanes (HCHs): A
Combined Experimental Investigation and Theoretical Calculation
Received 00th January 20xx,
Accepted 00th January 20xx
Xu Liang,*a, b Minzhi Li,a John Mack,*c Kevin Lobbc and Weihua Zhu*a, b
DOI: 10.1039/x0xx00000x
The enantioselective electrocatalysis of α-, β-, γ- and δ-hexachlorocyclohexanes (HCHs) by tetrakis-pentafluorophenyl-
Fe(III)porphyrin is described. The first example of the combined use of electrochemical measurements and theoretical
calculations to determine the mechanism of the enantioselective C−Cl bond cleavage of the electrocatalysis is reported.
The electrochemical measurements demonstrate that the reactivity of the HCHs follows the order γ-HCH > α-HCH > δ-HCH
> β-HCH. Steric considerations and a molecular orbital theory approach can be used to rationalize the enantioselective
nature of the catalysis based on the ease of approach of each Cl atom to the central Fe(I) ion and a considerations of the
nodes on the C−Cl bonds that weaken these bonds in a manner that results in bond cleavage and the formaꢀon of an Fe−Cl
bond.
www.rsc.org/
intermediates and the mechanism of the degradation
processes[7]. Electrocatalysis with macrocyclic transition metal
complexes, such as metallophthalocyanines (MPcs)[8] and
Introduction
Organochlorides are organic compounds that contain at
least one covalent C−Cl bonds have been used in a wide range
of applications in the past decades, and the level of agriculture
has also been enhanced significantly[1]
metalloporphyrins[9] is particularly attractive due to the highly
efficient and facile procedures that are involved and the low
cost. Typically, when a phthalocyanine is used, a central
divalent metal ion is reduced electrochemically to form a
[MIPc(−2)]− species, so it can react with alkyl halides (R−X) to
form a σ-bond and a MIII-macrocycle, since this results in the
release of a chloride ion through the cleavage of a C−Cl bond.
. Unfortunately,
organochlorides often do not degrade completely in the
environment, so despite restrictions being placed on their use
in agriculture in many countries, they are still present around
the world at significant concentrations as
a ubiquitous
For example, the tunable modulation of C
−Cl bond cleavages
can be achieved by changing the macrocyclic core[10], various
contaminant in soils and waters[2]. Recent advances in the
study of the carcinogenic properties of organochlorides have
demonstrated the need for new techniques to enable the
efficient removal of organochlorides. It has been reported that
microorganisms can be used to degrade organochlorides, but
the formation of further organochloride products and the low
efficiency of the degradation has limited further progress with
this method[3]. Recently, the focus of research in this field has
substituents,
metal
center
and
even
magnetic
nanomaterials[11]. Additionally, the full dechlorination of a
toxic organochloride, DDT, was successfully carried out
through a molecular electrochemical process in 2017[12]
.
Further, as well-known organochloride derivatives,
hexachlorocyclohexanes (HCHs) describes any of several
polyhalogenated organic compounds consisting of
a
moved to C−Cl bond cleavage through photocatalysis[4]
chemical catalysis[5] and electrochemical catalysis[6]
and
,
cyclohexane ring with one chlorine and one hydrogen attached
to each of the carbon atoms, and there are many isomers for
this structure, which differ by the stereochemistry of the Cl
,
several related results have been described on catalyst
preparation, structure-property relationships, reaction
atoms[13]
.
This journal is © The Royal Society of Chemistry 2015
J. Name., 2013, 00, 1-3 | 1
Please do not adjust margins

Please do not adjust margins
Dalton Transactions
Page 2 of 8
View Article Online
DOI: 10.1039/C8DT02510J
ARTICLE
Journal Name
HCHs have been used as models for analyzing the effects investigation and theoretical calculation of enantioselective
of the different geometries of the large Cl atoms and dipolar C−Cl bond cleavage through electrochemical processes is
bonds on the stability of different cyclohexane conformations, reported. (TF5PP)Fe(III)Cl (1), an iron porphyrin containing used
such as α-, β-, γ-, and σ-HCHs (Scheme 1) are the four most strongly electron-withdrawing substituents meso-aryl rings, is
to explore the reaction mechanism in depth.
Experimental
General
All reagents and solvents for electrochemical
measurements were of commercial spectroscopically pure
grade and were used without further purification except
where noted. Cyclic voltammetry measurements were carried
abundant isomers in nature, but the reactivity of these
out in a three-electrode cell using a Chi-730D electrochemistry
enantiomers is quite different due to the differing
station. A glassy carbon disk electrode was used as the working
arrangements in the axial and equatorial (a- and e-) type bonds
electrode, and the counter and reference electrodes were
platinum mesh and a saturated calomel electrode (SCE),
respectively. An “H” type cell with a fritted glass layer to
separate the cathodic and anodic sections of the cell was used
for bulk electrolysis. Both the working and reference
electrodes were placed in one compartment while the counter
electrode was in the other cell compartment. An Agilent
HP6890 GC gas chromatography system with an HP5975-MSD
detector was used to separate and identify the products of
catalytic reductive dechlorination. The experimental
conditions and the methods used for removing
tetrabutylammonium perchlorate (TBAP) from the electrolysis
solution prior to the GC-MS measurements are described in
the literature.
Computational methods
DFT calculations were carried out for both the dianionic
species of
1 and the α-, β-, γ- and δ-HCH isomers by using the
Gaussian 09 software package[14] at the MN12-L/6-31G(d)[15]
and BP86/LANL2DZ/6-31G(d)[16] level of theory. Transition
states were identified by using semi-empirical PM6
calculations[17] for MN12-L/6-31G(d) optimized structures of
the dianionic species of
1 and the α-, β-, γ- and δ-HCH isomers,
since several attempts to use a DFT approach proved to be too
computationally expensive.
Results and discussions
Electrochemical Characterization
Tetrakis-pentafluorophenyl
-Fe(III)porphyrin
(
1)
was
selected for study, since the electron withdrawing meso-
substituents stabilize electrogenerated anion radical species
that can be used to catalyze the C–Cl bond cleavage of HCHs
through
electrochemical
catalysis.
Reductive
cyclic
voltammetry (CV) measurements were carried out for
(TF5PP)Fe(III)Cl in DMF containing 0.1 M TBAP as a supporting
electrolyte at room temperature (Figure 1). Three reversible
processes are observed at −0.04, −0.85 and −1.35 V, with
metal and porphyrin ring reduction steps leading to the
formation of a [FeIPor]2− species. As has been reported
previously, reduced metalloporphyrin π-anions generally
in the chair conformer cyclohexane system. The reaction
mechanism for the C−Cl bond cleavage reacꢀon during
molecular
electrochemical
catalysis
with
reduced
metalloporphyrin anion species is still not fully understood. In
this study, the first example of a combined experimental
2 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2015
Please do not adjust margins

Please do not adjust margins
Dalton Transactions
Page 3 of 8
View Article Online
DOI: 10.1039/C8DT02510J
Journal Name
ARTICLE
while the doubly reduced [FeIPor]– anion has a split Soret band
at 384 and 423 nm in the absence of HCHs as shown in Figure
2, along with an additional broad absorption band at 590 nm in
the Q band region. Similar spectral transformations were
observed upon addition of 5.0 eq of β-HCH, and this indicates
that there is no significant interaction between β-HCH and
doubly reduced [FeIPor]– anion under these reaction
conditions. Interestingly, significant spectral changes were
observed upon the addition of 5.0 eq of γ-HCH. There is a
decrease in the intensity of the Soret band at 423 nm, and a
shoulder band absorption is observed at 440 nm. When α- and
σ-HCHs were used instead, similar spectral changes were
observed, but the intensity of the shoulder band weakens so
that γ-HCH > α-HCH > σ-HCH. This can be attributed to the
decrease in the number of a-type C–Cl bonds in the HCH
system.
enhance the rate of electrochemical reactions[9]
. Upon
addition of 1.0 eq of hexchlorocyclohexane (HCH), little or no
change is observed in the CV measurements for β-HCH. When
σ-, α- and γ-HCHs were used, however, which have one, two
and three a-type C−Cl bond, respecꢀvely, there is a stepwise
increase in the peak current, and this clearly illustrates that
there is
a relationship between the intensity of the
electrochemical response and the number of a-type bonds. An
increase in the reduction peak current for the
[FeIPor]−/[FeIPor)]2− process is observed as a function of
increasing HCHs concentration (Figure 1, right), where ip and ip0
are the measured cathodic peak currents obtained from the
CV of the porphyrin in the presence and absence of different
concentration of HCHs. The order of the ip/ip0 ratio in DMF
solutions containing the same concentration of
1 is γ-HCH > α-
HCH > σ-HCH > β-HCH. This also provides evidence that the
observed trends in the reaction rates between the doubly
reduced [FeIPor]2− species and the different HCHs is related to
which isomers contain the largest number of a-type C−Cl
bonds.
Controlled-Potential Bulk Electrolysis
Controlled-potential bulk electrolysis was carried out in
DMF solution containing
1
(2.0 × 10–4 M), 0.1 M TBAP and 15.0
Spectroelectrochemical Characterization
eq α-, β-, and γ-HCH (3.0 × 10–3 M). The bulk electrolysis
potential was set at –1.70 V which is sufficient to generate the
triply reduced dianion species [FeIPor]2– and also to reduce the
anticipated homogeneously generated σ-bonded [FeIIIPor]+-
HCH products. After 6 h of electrolysis, no change was
observed by GC-MS when β-HCH was used as the starting
material, while in contrast, α- and γ-HCH had disappeared
from solution within 5 and 4 h, respectively (Figure 3). The
In situ spectroelectrochemical measurements were also
carried out. The [FeIPor]2– dianion species was
electrogenerated from [FeIIIClPor] in the presence of four
different types of HCH, and the spectral changes were
monitored to provide
a better understanding of the
mechanism of the C–Cl bond cleavage. The UV-visible
absorption spectra of the electrochemical reduced [FeIPor]–
anion are shown in Figure 2. The controlled potential was set
presence
of
pentachlorocyclohexane
(PCCH),
at –1.05V so that
species[18]
The progress of the catalytic reaction was
1
can be completely reduced to the [FeIPor]2–
tetrachlorocyclohexadiene (TCDN) and trichlorobenzene (TCB)
and their geometric isomers was confirmed as intermediates
or final products of the C–Cl bond cleavage reaction of α-HCH
.
monitored by measuring the UV-visible spectra as a function of
time. The [FeIPor]– species has a single Soret band at 423 nm in
DMF and three visible region bands at 500, 566, and 630 nm,
(
Figure 3). In contrast, TCDN was not observed when γ-HCH
was used instead. The distribution of the geometric isomers of
This journal is © The Royal Society of Chemistry 2015
J. Name., 2013, 00, 1-3 | 3
Please do not adjust margins

Please do not adjust margins
Dalton Transactions
Page 4 of 8
View Article Online
DOI: 10.1039/C8DT02510J
ARTICLE
Journal Name
in which the Cl atom is lost. The reason for this is clear. The
3dz2 electron density is distributing in a highly antibonding
LUMO and is hence weakening one or more C−Cl bonds. Raised
energy transitions at the semi-empirical PM6 level make it
possible for transition states to be identified for C–Cl bond
cleavage in close proximity to the Fe atom (Figure 4, top). An
a-type Cl atom is most suitable for this for steric reasons, in
particular an a-type chlorine with no adjacent e-type chlorine
atoms. Although the approach of e-type C–Cl bonds is less
favored for steric reasons, it is also possible when there is
either none or only one adjacent e-type C–Cl bonds. As shown
in the bottom left part of Figure 4, the abstraction of an axial
chlorine atom from the highest energy conformation of δ-HCH
can be readily achieved in this manner, but a similar approach
is not possible in the case of β-HCH due to hindered access of
the e-type Cl atom to the central FeI ion (Figure 4, bottom
right). This provides an obvious reason why there is no
electrochemical reaction when β-HCH is used under the same
reaction conditions.
Transition State and Energy Calculation
The essential requirement for the formation of
a
pentachlorocyclohexyl radical is the release of a Cl radical
(representative atomic spin densities are provided in the ESI†)
through an interaction with the singly occupied 3dz2 orbital of
the Fe(I) ion, so the approach of the C–H bond to the iron
center to form an unstable Fe–C bond is also possible if the
adjacent Cl atom is transferred to the porphyrin ring (Figure 5).
The formation of a positively charged carbon atom is required
on the porphyrin ring after the subsequent abstraction of the
chlorine atom to complete this pathway, but in terms of
energetics the simple abstraction of a chlorine atom by the
iron center is generally more energetically favorable when the
transition states that were identified in PM6 calculations are
taken into consideration (Table 1). In the context of the higher
energy conformation of δ-HCH (Figure 5), the second process
is energetically less favorable by ca. 30 kcal/mol.
trichlorobenzenes could be determined by GC-MS through
comparison with standard samples, and the 1,2,4-
trichlorobenzene was confirmed to be present at a higher ratio
(Figure 3 and Figure S1, see ESI†). Finally, in order to confirm
whether trichlorobenzenes are the final C–Cl bond cleavage
products, reductive electrochemical measurements were
carried out in DMF containing 0.1 M TBAP (Figure S2, see ESI†).
Little to no electrochemical changes were observed for all of
the reductive electrochemical measurements of [FeIIIClPor]
1
upon addition of 1.0 eq of 1,3,5-, 1,2,4- and 1,2,3-
trichlorobenzenes, and this indicates that the electrochemical
catalyzed C–Cl bond cleavage reactions stop at this point due
to the greater stability aromatic sp2 hybridized C(sp2)–Cl bond
Molecular Orbital Calculations
The relative reactivities of the four isomeric HCH
structures can be readily rationalized based on an inspection
of the angular nodal patterns of the antibonding LUMO of the
HCH (Figure 6) that interacts with the 3dz2 orbital of the Fe(I)
ion. The formation of transition states based on Fe−Cl bond
formation is facilitated by the presence of a LUMO on the HCH
which is anti-bonding with respect to several of the C–Cl
bonds. The local cleavage mechanism for the C–Cl bond
(
Figure S2, see ESI†).
Quantum Chemical Calculations
A series of modelling calculations were carried out to study
the interaction between the [FeIPor]2–species and the various
HCH conformations to identify transition states (Table 1).
Details for these transition states including the results of
normal coordinate analyses and Cartesian coordinates are
provided as supplemtary information (Table S1, see ESI†) . Low
spin resulting in a singly occupied 3dz2 MO on the central FeI
ion was assumed, since DFT calculations indicated that this
provides an energetically favored triplet multiplicity for the
ring and metal reduced [FeIPor]2– species. Various DFT
methods including MN12-L and BP86/LANL2DZ/6-31G(d)
mixed basis based scans of HCHs, demonstrated that the
increasing proximity of Cl to the porphyrin Fe center resulted
in a marked weakening of both local and remote C−Cl bonds,
sometimes resulting in extremely low or barrierless transitions
cleavage
of
HCHs
through
the
formation
of
pentachlorocyclohexyl and chlorine radicals requires
unhindered access of a chlorine atom to the electrochemically
reduced iron porphyrin center. An example of the spin
densities for this process is provided as supplementary
information. The LUMO for the solitary γ-HCH ring flip
conformation has larger nodes on the a-type Cl atoms and
smaller nodes on two of the e-type Cl atoms (Figure 6). Thus
there are three major orientations and two minor ones with
which an interaction with the central Fe(I) ion is likely to result
4 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2015
Please do not adjust margins

Please do not adjust margins
Dalton Transactions
Page 5 of 8
View Article Online
DOI: 10.1039/C8DT02510J
Journal Name
ARTICLE
in reactivity. Statistically, this increases the possibility of a on the remaining substituent, the 1,3-diaxial interactions make
successful interaction compared to α-HCH since for α-HCH, the this conformation highly disfavored in energy terms as is clear
lower energy conformation has large LUMO nodes on only two from the A value of 2.15 kcal/mol (Figure 6), which is
a-type Cl atoms and smaller nodes on two e-type Cl atoms, determined using the difference in the Gibbs free energy for a-
while the higher energy conformation has large LUMO nodes and e-type C–Cl bonds in mono-substituted cyclohexanes and
on four a-type Cl atoms (Figure 6). This means that although a consideration of the number of both types of bond in the
there are several possibilities for a successful orientation structures of the various structures in Figure 6. The lower
leading to reactivity from a steric standpoint, overall an energy conformation of δ-HCH has favorable LUMO nodes on
interaction with the FeI ion is not as likely as it is for γ-HCH.
Although the higher energy conformation of δ-HCH has e-
strong LUMO nodes on five Cl atoms and a small LUMO node
four substituents, but the steric requirements for these three
This journal is © The Royal Society of Chemistry 2015
J. Name., 2013, 00, 1-3 | 5
Please do not adjust margins

Please do not adjust margins
Dalton Transactions
Page 6 of 8
View Article Online
DOI: 10.1039/C8DT02510J
ARTICLE
Journal Name
Table 1. Relative energies (kcal/mol) of the transition states formed by the dianionic species of 1 and α-, β-, γ- and δ-HCHs that were
identified during PM6 calculations. All energies are in kcal/mol
Fe−H interacꢀon
HCH-1 associated
0.1
Lower energy conformera
15.4
---
23.8
19.4
16.3
31.5
29.2
Higher energy conformera
---
---
---
29.2
22.7
α-HCH
β-HCH
γ-HCH
δ-HCH
0.0
1.1
Fe−Cl bond formaꢀon
α-HCH
β-HCH
γ-HCH
0.1
0.0
-8.0
18.0
---
−5.4
4.6
8.2
−4.3
---
1.5
δ-HCH
-15.8
−4.2
7.8
---
−3.4
a - The energies of the transition states were calculated relative to the free energies of the 1 and HCH isomer structures prior to their
interaction.
6 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2015
Please do not adjust margins

Please do not adjust margins
Dalton Transactions
Page 7 of 8
View Article Online
DOI: 10.1039/C8DT02510J
Dalton Transitions
ARTICLE
type Cl atoms to interact with the porphyrin are too high, due the C–Cl bonds are all weakened equally, no individual bond is
to their equatorial nature and the presence of further adjacent weakened sufficiently for facile cleavage.
e-type Cl atoms. As such, there is effectively only one node
available that can easily react with the FeI ion, since the
Conclusions
weakening of two of the C−Cl bonds is not possible due to the
absence of nodal planes. For the highly energetically favored
The use of molecular electrocatalysis for the
all-e-type Cl atom conformation of β-HCH
(Figure 6),
dechlorination of α-, β-, γ- and δ-hexachlorocyclohexanes
(HCHs) in the presence of the dianionic species of tetrakis-
pentafluorophenyl-Fe(III)porphyrin has been analyzed through
electrochemical measurements and theoretical calculations.
The reactivity of the HCHs follows the order γ-HCH > α-HCH >
δ-HCH > β-HCH. Steric considerations related to differing
numbers of a- and e-type bonds in the possible ring flip
conformations for each isomer and the ease of approach of
each chlorine atom to the central Fe(I) ion, along with the
effect of the magnitude of the nodes on each C−Cl bond in the
LUMOs of the HCHs on relative bond strengths, can be used to
accessibility to the FeI ion of the porphyrin center is highly
problematic for steric reasons. From the standpoint of the
number of a-type C−Cl bonds alone, the β-HCH would be
expected to be the most reactive in terms of the LUMO alone,
since the LUMO has nodes over all of the Cl atoms (Figure 6
)
and a favorable transition state was identified in the PM6
calculations (Table 1). This conformation is highly energetically
disfavored, however, due to the 1,3-diaxial interactions that
result in an A value of 2.43 kcal/mol. Further to this, there may
also be symmetry considerations that come into play, since if
This journal is © The Royal Society of Chemistry 2015
J. Name., 2013, 00, 1-3 | 7
Please do not adjust margins

Please do not adjust margins
Dalton Transactions
Page 8 of 8
View Article Online
DOI: 10.1039/C8DT02510J
ARTICLE
Journal Name
13 J. Moisey, A. Fisk, K. Hobson, R. Norstrom, Environ. Sci.
Technol., 2001, 35, 1920.
fully rationalize the enantioselective nature of the
electrocatalysis.
14 M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A.
Robb, J. R. Cheeseman, G. Scalmani, V. Barone, B. Mennucci,
G. A. Petersson, H. Nakatsuji, M. Caricato, X. Li, H. P.
Hratchian, A. F. Izmaylov, J. Bloino, G. Zheng, J. L.
Sonnenberg, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J.
Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H.
Nakai, T. Vreven, J. A. Montgomery Jr., J. E. Peralta, F.
Ogliaro, M. Bearpark, J. J. Heyd, E. Brothers, K. N. Kudin, V.
N. Staroverov, R. Kobayashi, J. Normand, K. Raghavachari, A.
Rendell, J. C. Burant, S. S. Iyengar, J. Tomasi, M. Cossi, N.
Rega, M. J. Millam, M. Klene, J. E. Knox, J. B. Cross, V.
Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. E. Stratmann,
O. Yazyev, A. J. Austin, R. Cammi, C. Pomelli, J. W. Ochterski,
R. L. Martin, K. Morokuma, V. G. Zakrzewski, G. A. Voth, P.
Salvador, J. J. Dannenberg, S. Dapprich, A. D. Daniels, Ö.
Farkas, J. B. Foresman, J. V. Ortiz, J. Cioslowski and D. J. Fox,
Gaussian 09, Revision D.01, Gaussian, Inc., Wallingford, CT,
2009.
Acknowledgements
Financial support was provided by the National Scientific
Foundation of China (No. 21701058), NSFC of Jiangsu province
of China (no. BK20160499) and the fund from the State Key
Laboratory of Coordination
Chemistry (SKLCC1710,
SKLCC1817), the fund from Key Laboratory of Functional
Inorganic Material Chemistry (Heilongjiang University) of
Ministry of Education to XL and WZ, and a National Research
Foundation (South Africa) CSUR grant (93627) to JM. The
theoretical calculations were carried out at the Centre for High
Performance Computing in Cape Town.
15 R. Peverati, D.G. Truhlar, Phys. Chem. Chem. Phys., 2012,
14., 13171.
Notes and references
16 a) A. D. Becke, Phys. Rev. A, 1988, 38, 3098; b) J. Perdew,
Phys. Rev. B, 1986, 33, 8822.
17 J. J. P. Stewart, J. Mol. Model., 2007, 13, 1173.
1
a) G. Famiglini, P. Palma, E. Pierini, H. Trufelli and A.
Cappiello, Anal. Chem., 2008, 80, 3445; b) N. Durán, E.
Esposito. App. Catal. B: Environ., 2000, 28, 83.
18 a) K. Kadish, E. Caemelbecke, F. D'Souza, C. Medforth, K.
Smith, A. Tabard, R. Guilard, Inorg. Chem., 1995, 34, 2984; b)
K. Araki, H. Toma, J. Electroanal. Chem., 1991, 297, 301; c) K.
Araki, H. Toma, Electrochim. Acta, 1999, 44, 1577.
2
a) A. Solano, C. Araújo, J. Melo, J. Peralta-Hernandez, D.
Silva, C. Martínez-Huitle. App. Catal. B: Environ., 2013, 7, 112;
b) F. Moreira, R. Boaventura, E. Brillas, V. Vilar. App. Catal. B:
Environ., 2017, 202, 217.
3
4
a) E. Brillas, C. Martínez-Huitle. App. Catal. B: Environ., 2015,
166–167, 603; b) J. Nelson, J. Jiang, S. Zinder, Environ. Sci.
Technol., 2014, 48, 3776.
a) S. Pavlostathis, M. Prytula, Environ. Sci. Technol., 2000, 34
4001; b) X. Fan, L. Zang, M. Zhang, H. Qiu, Z. Wang, J. Yin, H.
Jia, S. Pan, C. Wang, Chem. Mater., 2014, 26, 3169; c) M.
Humayun, Y. Qu, F. Raziq, R. Yan, Z. Li, X. Zhang, L. Jing,
Environ. Sci. Technol., 2016, 50, 13600.
5
6
a) E. Patterson, C. Cramer, D. Truhlar, J. Am. Chem. Soc.,
2001, 123, 2025; C. Baumanis, J. Bloh, R. Dillert, D.
Bahnemann, J. Phys. Chem. C, 2011, 51, 25442; b) H. Choi, S.
Al-Abed, S. Agarwal, Environ. Sci. Technol., 2009, 43, 4137; c)
N. Lombard, U. Ghosh, B. Kjellerup, K. Sowers, Environ. Sci.
Technol., 2014, 48, 4353.
a) K. McCauley, D. Pratt, S. Wilson, J. Shey, T. Burkey, van der
Donk, J. Am. Chem. Soc., 2005, 127, 1126; b) X. Mao, A.
Ciblak, M. Amiri, A. Alshawabkeh, Environ. Sci. Technol.,
2011, 45 6517; c) A. Matsunaga, A. Yasuhara, Environ. Sci.
Technol., 2003, 37, 3435.
7
8
9
a) J. Fritsch, K. McNeill, Inorg. Chem., 2005, 44, 4852; b) W.
Zhu, T. Huang, M. Qin, M. Li, J. Mack, X. Liang, J. Electroanal.
Chem., 2016, 774, 58; c) K. Jeon, N. Lee, S. Bae, W. Goddard
III, H. Kim, W. Lee, J. Phys. Chem. A, 2015, 119, 5714.
a) A. Krzemińska, P. Paneth, Environ. Sci. Technol., 2016, 50
,
6293; b) J. Wen, B. Yu, T. Huang, J. Mack, M. Wildervanck, T.
Nyokong, M. Li, W. Zhu, X. Liang, J. Electroanal. Chem., 2017,
803, 111.
a) J. Shao, A. Thomas, B. Han, C. Hansen, J. Porphyrins
Phthalocyanines, 2010, 14, 133; b) M. Li, L. Liang, C. Ni, X.
Liang, W. Zhu, J. Electroanal. Chem., 2016, 766, 135.
10 a) L. Ukrainczyk, M. Chibwe, T. Pinnavaia, S. Boyd, Environ.
Sci. Technol., 1995, 29, 439; b) P. Afanasiev, A. Sorokin, Acc.
Chem. Res.; 2016, 49, 583; c) C. Gantzer, L. Wackett, Environ.
Sci. Technol., 1991, 25, 715–722.
11 W. Zhu, T. Huang, M. Li, L. Zheng, S. Bao, X. Liang,
ChemistrySelect, 2017, 2, 645.
12 X. Liang, T. Huang, M. Li, J. Mack, M. Wildervanck, T.
Nyokong, W. Zhu, Appl. Cat. A, 2017, 545, 44.
8 | J. Name., 2012, 00, 1-3
This journal is © The Royal Society of Chemistry 2015
Please do not adjust margins