Inorganic Chemistry
Article
data are taken in an Agilent technologies spectrophotometer model
8453 fitted with a diode-array detector. Resonance Raman data are
collected with a Trivista 555 spectrograph (Princeton Instruments)
using 415 nm excitation from a Kr+ laser (Coherent, Sabre Innova
SBRC-DBW-K). X-ray diffraction data for compound 3 are collected
by using a VENTURE PHOTON100 CMOS Bruker diffractometer
with Microfocus IμS source Cu Kα radiation. A crystal is mounted on
a CryoLoop (Hampton Research) with Paratone-N (Hampton
Research) as cryoprotectant and then flash frozen in a nitrogen-gas
stream at 100 K. For compounds, the temperature of the crystal is
maintained at the selected value (100 K) by means of an N-Helix
series Cryostream cooling device to within an accuracy of 1 K. The
data are corrected for Lorentz polarization and absorption effects. The
structures are solved by direct methods using SHELXS-9788 and
refined against F89 by full-matrix least-squares techniques using
SHELXL-2018 with anisotropic displacement parameters for all non-
hydrogen atoms. Hydrogen atoms are located on a difference Fourier
map and introduced into the calculations as a riding model with
isotropic thermal parameters. All calculations are performed by using
the Crystal Structure crystallographic software package WINGX.90
B. Construction of the Modified Electrode (EPG Electrode)
for Heterogeneous Electrochemical Experiments. A 100 μL
aliquot of 1 mM catalyst in methanol has been deposited on a freshly
cleaned EPG electrode mounted on an RRDE setup. Once the solvent
is fully evaporated, the surface has been rinsed with methanol and
milli-Q water and thoroughly dried under N2 atmosphere before each
of the electrochemical experiments.
atoms. Frequency calculations are performed on each optimized
structure (in the gas phase) using the same basis set to ensure that it
was a minimum on the potential energy surface. Calculated IR spectra
are obtained from the frequency calculations.
ASSOCIATED CONTENT
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sı
* Supporting Information
The Supporting Information is available free of charge at
Details of the experimental procedure, materials, syn-
thesis of the complexes with their spectroscopic and
crystallographic characterization, additional electro-
chemical and spectroscopic data, optimized coordinates
Accession Codes
CCDC 1922834 contains the supplementary crystallographic
data for this paper. These data can be obtained free of charge
bridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
C. Cyclic Voltammetry (CV) Experiments. All homogeneous
cyclic voltammograms are performed in dry acetonitrile containing 1
mM catalysts, and TBAP (100 mM) is used as the supporting
electrolyte. In the case of the concentration (of the catalysts)
dependent catalysis, the concentration of TBAP has been kept 100
times with respect to the catalyst’s concentration. A stock of 200 mM
substrate (here, TBAH) in acetonitrile is prepared and used in the
electrochemical experiments. Heterogeneous pH-dependent LSVs are
done in sodium phosphate buffer (containing 100 mM Na2HPO4 and
100 mM KPF6) as mentioned. In all of the cases, platinum and sealed
aqueous Ag/AgCl (saturated KCl) are used as counter and reference
electrodes, respectively.
D. Electron Paramagnetic Resonance (EPR) and rR Spec-
troscopy. EPR and rR spectroscopy are performed followed by
electrochemical oxidation of the (i) catalyst (1 mM) dissolved in
acetonitrile (containing 100 mM TBAP) and (ii) catalyst (1 mM) in
the presence of 7 mM TBAH in acetonitrile containing 100 mM
TBAP. Typically, a 1 mM solution of the catalyst in dry and degassed
acetonitrile has been electrolyzed under the anaerobic condition at
the mentioned potentials using a Hg-pool electrode (area 2.7 cm2) as
the working electrode and platinum and sealed aqueous Ag/AgCl
(saturated KCl) as counter and reference electrodes, respectively.
Control potential electrolysis has been performed until the total
charge consumption reaches 1 C. The samples are collected from the
electrolytic solution and frozen in liquid N2, and then ESR and rR
data are recorded at 77 K.
AUTHOR INFORMATION
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Corresponding Authors
Ally Aukauloo − Université Paris Saclay, ICMMO CNRS
8182, F-91405 Orsay, Cedex, France; Institute for integrative
Biology of the Cell (I2BC), CEA, CNRS Université Paris-
Saclay, UMR 9198, F-91191 Gif-sur-Yvette, France;
Abhishek Dey − School of Chemical Sciences, Indian
Association for the Cultivation of Science, Jadavpur, Kolkata
Authors
Samir Chattopadhyay − School of Chemical Sciences, Indian
Association for the Cultivation of Science, Jadavpur, Kolkata
Arnab Ghatak − School of Chemical Sciences, Indian
Association for the Cultivation of Science, Jadavpur, Kolkata
700032, India
Youngju Ro − Université Paris Saclay, ICMMO CNRS 8182,
F-91405 Orsay, Cedex, France
Régis Guillot − Université Paris Saclay, ICMMO CNRS
8182, F-91405 Orsay, Cedex, France
Anisotropic Simulation (AniSimu/FA Version: 2.4.0) software
from JEOL is used to simulate the EPR data. A∥, g∥, and g⊥ values are
obtained from the simulation.
Zakaria Halime − Université Paris Saclay, ICMMO CNRS
8182, F-91405 Orsay, Cedex, France
E. In-Situ FTIR-Spectroelectrochemical Experiments. FTIR-
spectroelectrochemical experiments are performed using a RT-
OTTLE cell in dry acetonitrile containing 4 mM of catalysts. The
concentration of TBAP has been kept 100 times corresponding to the
concentration of the catalysts. During the FTIR spectroelectrochem-
ical experiments under catalytic turnover, 7 mM TBAH is used as the
substrate. A solution of 400 mM TBAP in acetonitrile (during
noncatalytic conditions) and 400 mM TBAP + 7 mM TBAH in
acetonitrile (during catalytic conditions) are used to collect the blank
spectrum during the FTIR experiments.
F. DFT Calculations. Gaussian 03 software package is used to
perform the calculations on the Inorganic HPC cluster at IACS.91 The
spin-unrestricted formalism is used to optimize the geometries using
both the M06-2X functional and the 6-311G* basis set for all of the
Complete contact information is available at:
Funding
This work was supported by the Department of Science and
Technology Grant (SERB EMR-080063), DST/TMD/HFC/
2K18/90(G), the LABEX CHARMMMAT, and the French
Infrastructure for integrated Structural Biology (FRISBI)
ANR-10-INSB-05−01.
Notes
The authors declare no competing financial interest.
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Inorg. Chem. 2021, 60, 9442−9455