Synthesis and characterization of diiron ethane-1,2-dithiolate complexes with tricyclohexylphosphine, methyl diphenylphosphinite, or tris(2-thienyl)phosphine coligands

Article abstract of DOI:10.1007/s11243-019-00339-x

We have prepared three diiron ethane-1,2-dithiolate complexes [Fe₂(CO)₅L(μ-SCH₂CH₂S)] [L = P(C₆H₁₁)₃, 2; Ph₂POCH₃, 3; P(2-C₄H₃S)₃

Full text of DOI:10.1007/s11243-019-00339-x

Transition Metal Chemistry
https://doi.org/10.1007/s11243-019-00339-x
Synthesis and characterization of diiron ethane‑1,2‑dithiolate
complexes with tricyclohexylphosphine, methyl diphenylphosphinite,
or tris(2‑thienyl)phosphine coligands
Lin Yan1 · Ao Li2 · Qi‑Min Xiao2 · Xu‑Feng Liu1 · Yu‑Long Li2 · Zhong‑Qing Jiang3 · Hong‑Ke Wu4
Received: 11 January 2019 / Accepted: 15 June 2019
© Springer Nature Switzerland AG 2019
Abstract
We have prepared three diiron ethane-1,2-dithiolate complexes [Fe2(CO)5L(µ-SCH2CH2S)] [L=P(C6H11)3, 2; Ph2POCH3,
3; P(2-C4H3S)3, 4] by CO exchange of the starting complex [Fe2(CO)6(µ-SCH2CH2S)] (1) with the corresponding phosphine
ligands tricyclohexylphosphine, methyl diphenylphosphinite, or tris(2-thienyl)phosphine in the presence of Me3NO as an
oxidant for CO. The complexes have been characterized by elemental analysis, spectroscopy, and single-crystal X-ray dif-
fraction analysis.
Introduction
a signifcant role in shuttling protons to and from the iron
atoms [13]. Guided by this structural information, a great
number of diiron azadithiolate complexes of general for-
mula [Fe2(CO)6{μ-SCH2N(R)CH2S}] have been prepared
and characterized in recent decades [14–17]. In addition,
alternative ligands such as cyanides [18], phosphines [19],
thioethers [20], and N-heterocyclic carbenes (NHC) [21]
have also been introduced, in order to mimic the ligands at
the active site of these enzymes.
Since the initial characterization of the active site of [FeFe]-
hydrogenases [1–5], much efort has been devoted to the
design and synthesis of a large number of diiron complexes
of the general formula [Fe2(CO)6–n(L)n(μ-SRS)] (n =0–6)
in order to mimic the structural and functional attributes
of these enzymes. [FeFe]-hydrogenases are efcient cata-
lysts for the reduction of protons to H2 which is a promising
source of clean energy [6–8]. X-ray crystallographic studies
have revealed that the active site of [FeFe]-hydrogenases
consists of a diiron cluster with a bridging dithiolate cofac-
tor, also ligated by carbonyls, cyanides, and a cysteinyl
ligand connected to a tetrairon cluster [9, 10]. FTIR [11]
and density functional theory (DFT) [12] studies have con-
frmed that the bridging dithiolate cofactor is 2-azapropane-
1,3-dithiolate and furthermore that the nitrogen atom plays
The diiron ethane-1,2-dithiolate complex
[Fe2(CO)6(µ-SCH2CH2S)] (1) was reported more than
30 years ago [22], being prepared by heating Fe3(CO)12
with 1,2-ethanedithiol in toluene solution. The reactions of
complex 1 with other ligands have been widely studied, due
to its structural similarity with the diiron propane-1,3-dithi-
olate complex [Fe2(CO)6(µ-SCH2CH2CH2S)] [23, 24]. In
continuation of our ongoing interests in diiron chemistry,
we have investigated the synthesis of some diiron ethane-
1,2-dithiolate complexes by CO exchange of the parent com-
plex 1 with phosphine ligands. We believe that such phos-
phine ligands can mimic the cyanides found in the active
site of [FeFe]-hydrogenases. In this contribution, we report
the synthesis and characterization of three diiron ethane-
1,2-dithiolate complexes with tricyclohexylphosphine,
methyl diphenylphosphinite, or tris(2-thienyl)phosphine
coligands, together with their X-ray crystal structures.
* Xu-Feng Liu
nkxfiu@126.com
1
School of Materials and Chemical Engineering, Ningbo
University of Technology, Ningbo 315211, China
2
College of Chemistry and Environmental Engineering,
Sichuan University of Science and Engineering,
Zigong 643000, China
3
Department of Physics, Key Laboratory of ATMMT
Ministry of Education, Zhejiang Sci-Tech University,
Hangzhou 310018, China
4
College of Chemical Engineering, Zhejiang University
of Technology, Hangzhou 310014, China
Vol.:(0123456789)
1 3

Transition Metal Chemistry
instead of tricyclohexylphosphine; 0.045 g (73%) of complex
4 was obtained as a red solid. IR (CH2Cl2, cm−1): νC≡O 2048
(vs), 1991 (vs), 1943 (m). 1H NMR (500 MHz, CDCl3): 7.67
(s, 3H, thienylH), 7.53 (s, 3H, thienylH), 7.17 (s, 3H, thie-
nylH), 2.06 (d, J=8 Hz, 2H, SCH2), 1.63 (d, J=8 Hz, 2H,
SCH2) ppm. 31P{1H} NMR (200 MHz, CDCl3, 85% H3PO4):
30.26 (s) ppm. Anal. Calcd. for C19H13Fe2O5PS5: C, 36.56;
H, 2.10. Found: C, 36.31; H, 2.28%.
Experimental
Tricyclohexylphosphine, methyl diphenylphosphinite, tris(2-
thienyl)phosphine, and Me3NO·2H2O were commercial
products that were used as received. Complex 1 was pre-
pared according to the literature procedure [22]. IR spectra
were recorded on a Nicolet MAGNA 560 FTIR spectrom-
eter. 1H, 31P{1H}, 13C{1H} NMR spectra were obtained on a
Bruker Avance 500 MHz spectrometer. Elemental analyses
were obtained with a Perkin-Elmer 240C analyzer.
X‑ray crystal structure determination
A single crystal of each complex was mounted on a Bruker
D8 QUEST difractometer. Data were collected at 296(2)
K using a graphite monochromator with MoKα radiation
(λ = 0.71073 Å) in the ω–ϕ scanning mode. Data collec-
tion and reduction were accomplished with APEX2 software
[25]. Absorption corrections were made with the SADABS
program [26]. Using OLEX2 [27], the structure was solved
by direct methods using the SHELXS program [28] and
refned by full-matrix least-squares techniques on F2. Hydro-
gen atoms were located using geometric methods. Details of
crystal data, data collections, and structure refnements are
summarized in Table 1.
Synthesis of [Fe2(CO)5{P(C6H11)3}(µ‑SCH2CH2S)] (2)
To a solution of [Fe2(CO)6(µ-SCH2CH2S)] (0.037 g,
0.1 mmol) and tricyclohexylphosphine (0.028 g, 0.1 mmol)
in CH2Cl2 (5 mL) was added a solution of Me3NO·2H2O
(0.011 g, 0.1 mmol) in MeCN (5 mL). The mixture was
stirred at room temperature for 1 h, and then, the solvent
was reduced on a rotary evaporator. The residue was sub-
jected to TLC using CH2Cl2/petroleum ether=1:3 (v/v) as
eluent. From the main red band, 0.042 g (68%) of complex
2 was obtained as a red solid. IR (CH2Cl2, cm−1): νC≡O 2043
1
(vs), 1977 (vs), 1921 (m). H NMR (500 MHz, CDCl3):
2.27–2.18 (m, 4H, CyH), 2.06–2.03 (m, 6H, CyH, and
SCH2), 1.92–1.91 (m, 6H, CyH, and SCH2), 1.83–1.77 (m,
6H, CyH), 1.55–1.47 (m, 6H, CyH), 1.32–1.26 (m, 9H,
CyH) ppm. 31P{1H} NMR (200 MHz, CDCl3, 85% H3PO4):
71.57 (s) ppm. 13C{1H} NMR (125 MHz, CDCl3): 216.90
(d, JP–C = 10.5 Hz, PFeCO), 210.71 (FeCO), 38.38 (d,
JP–C = 16.4 Hz, CyC), 30.18 (CyC), 36.31 (SCH2), 27.89
(d, JP–C =9.9 Hz, CyC), 26.42 (CyC) ppm. Anal. Calcd. for
C25H37Fe2O5PS2: C, 48.09; H, 5.97. Found: C, 48.28; H,
6.19%.
Electrochemical experiments
The electrochemical properties of complexes 2–4 were
studied by cyclic voltammetry (CV) in MeCN solution.
Electrochemical measurements were taken under nitrogen
using a CHI 620 Electrochemical work station. The support-
ing electrolyte n-Bu4NPF6 was recrystallized several times
from CH2Cl2 solution by the addition of hexane. CV scans
were obtained in a three-electrode cell with a glassy carbon
electrode (3 mm diameter) as the working electrode, a plati-
num wire as the counter electrode, and a nonaqueous Ag/
Ag+ electrode as the reference electrode. The potential scale
was calibrated against the Fc/Fc+ couple, and all values are
reported versus this reference.
Synthesis of [Fe2(CO)5(Ph2POCH3)(µ‑SCH2CH2S)] (3)
The procedure was similar to that for complex 2, except that
methyl diphenylphosphinite (0.022 g, 0.1 mmol) was used
instead of tricyclohexylphosphine; 0.039 g (70%) of com-
plex 3 was obtained as a red solid. IR (CH2Cl2, cm−1): νC≡O
2046 (vs), 1987 (vs), 1935 (m). 1H NMR (500 MHz, CDCl3):
7.71 (s, 4H, PhH), 7.47 (s, 6H, PhH), 3.59 (d, J = 11 Hz,
3H, CH3), 2.01 (s, 2H, SCH2), 1.73 (s, 2H, SCH2) ppm.
31P{1H} NMR (200 MHz, CDCl3, 85% H3PO4): 168.07 (s)
ppm. Anal. Calcd. for C20H17Fe2O6PS2: C, 42.89; H, 3.06.
Found: C, 42.68; H, 3.14%.
Results and discussion
Synthesis and characterization of complexes 2–4
The synthetic route to complexes 2–4 is shown in Scheme 1.
Treatment of the starting complex 1 with one equivalent of
the corresponding phosphine ligand tricyclohexylphosphine,
methyl diphenylphosphinite, or tris(2-thienyl)phosphine in
the presence of Me3NO as an oxidant for CO aforded the
target complexes in satisfactory yields. All three complexes
are air-stable red solids, soluble in medium-polarity solvents
such as CH2Cl2 and THF.
Synthesis of [Fe2(CO)5{P(2‑C4H3S)3}(µ‑SCH2CH2S)] (4)
The procedure was similar to that for complex 2, except
that tris(2-thienyl)phosphine (0.028 g, 0.1 mmol) was used
1 3

Transition Metal Chemistry
Table 1 Crystal data and
structure refnements details for
the complexes 2–4
Complex
2
3
4
Empirical formula
Formula weight
Temperature (K)
Crystal system
Space group
a (Å)
b (Å)
c (Å)
α (°)
β (°)
C25H37Fe2O5PS2
624.33
296(2)
Monoclinic
P21/n
11.7852(6)
11.7247(6)
21.7489(12)
90
103.700(2)
90
2919.7(3)
4
1.420
1.223
C20H17Fe2O6PS2
560.12
296(2)
Orthorhombic
Pbca
16.3721(7)
15.7473(7)
17.8364(8)
90
90
90
4598.5(4)
8
1.618
C19H13Fe2O5PS5
624.26
296(2)
Triclinic
P-1
9.2969(4)
10.4370(4)
13.4614(6)
88.5670(10)
75.6860(10)
72.6510(10)
1206.38(9)
2
1.719
1.731
628.0
0.2×0.2×0.2
MoKα (λ=0.71073)
4.742–55.172
−12≤h≤12
−13≤k≤13
−17≤l≤17
γ (°)
V (Å3)
Z
Dcalc (g cm−3
)
µ (mm−1
F(000)
)
1.547
2272.0
1304.0
Crystal size (mm3)
Radiation
0.3×0.2×0.18
MoKα (λ=0.71073)
4.43–61.512
−16≤h≤16
−16≤k≤16
−31≤l≤31
0.32×0.22×0.18
MoKα (λ=0.71073)
4.254–50.226
−19≤h≤18
−18≤k≤18
−21≤l≤21
2θ range (°)
hkl range
Refections collected
96939
90360
51965
Independent refections
Data/restraints/parameters
Goodness of ft on F2
8453 [Rint =0.0427]
8453/0/316
1.029
4099 [Rint =0.0484]
4099/0/281
1.185
5518 [Rint =0.0297]
5518/18/289
1.062
Final R indexes (I>2σ(I))
Final R indexes (all data)
Largest dif peak and hole/e Å−3
0.0357/0.0769
0.0603/0.0847
0.40/−0.34
0.0244/0.0657
0.0362/0.0793
0.46/−0.48
0.0761/0.2307
0.0798/0.2355
2.35/−1.37
Scheme 1 Synthesis of the
complexes 2–4
Me3NO
L
S
S
S
S
CO
L
L = P(C6H11)3, 2
= Ph2POCH3, 3
= P(2-C4H3S)3, 4
OC
OC
Fe
Fe
Fe
Fe
OC
OC
CO
CO
OC
OC
CO
CO
1
The IR spectra of complexes 2–4 each show three absorp-
tion bands in the region of 2048–1921 cm−1, which can be
assigned to the stretching vibrations of the terminal carbonyl
ligands, close to those of analogous complexes [29]. The
ν(C≡O) values are redshifted compared to those of the par-
ent complex 1 (2079, 2039, 2009, 1996 cm−1) [22] as well as
other all-carbonyl complexes [30], which is expected since
the phosphine ligands are more strongly electron donating
than CO [31]. The 1H NMR spectrum of complex 3 displays
two singlets at 2.01 and 1.73 ppm for the methylene protons,
probably due to the diferent steric efects of the phosphine
coligand. The 31P{1H} NMR spectra of complexes 2 and 4
each show single resonances at 71.57 and 30.26 ppm, respec-
tively, similar to those of some phosphine-substituted diiron
analogues [32, 33], but signifcantly larger than those of the
corresponding free phosphines. Meanwhile, the 31P{1H}
NMR spectrum of complex 3 exhibits a single resonance
at 168.07 ppm, notably diferent to those of complexes 2
and 4 because of the P–O bond in complex 3, but consistent
with the complex [Fe2(CO)5{P(OEt)3}(µ-SCH2CH2CH2S)]
(171.09 ppm) [19]. The 13C{1H} NMR spectrum of complex
2 shows a doublet at 216.90 ppm with a coupling constant
1
whereas the H NMR spectrum of complex 4 shows two
doublets at 2.06 and 1.63 ppm for the corresponding protons,
1 3

Transition Metal Chemistry
JP–C =10.5 Hz for the terminal carbonyls of the PFe(CO)2
moiety, plus a singlet at 210.71 ppm for the terminal carbon-
yls of the Fe(CO)3 unit.
P21/n with four molecules in the unit cell and one mole-
cule in the asymmetric unit. As shown in Fig. 1, complex
2 contains a diiron unit, which is coordinated by a bridging
ethane-1,2-dithiolate ligand, fve terminal carbonyls, and
a tricyclohexylphosphine ligand. The phosphorus atom of
the latter is located in an apical position of the distorted
octahedral Fe2 atom, similar to the related phosphine-
containing diiron complexes [Fe2(CO)5(Ph2PCH2Ph)
(µ-SCH2CH2S)] [34], [Fe2(CO)5{P(2-C6H4OCH3)3}
{µ-SCH2CH(CH2O2CFc)}] (Fc = ferrocenyl) [35], and
[Fe2(CO)5(PPh3)(µ-SCH2CH2CH2S)] [19]. The Fe1–Fe2
bond distance [2.4909(3) Å] is slightly shorter than that
X‑ray crystal structures of complexes 2–4
In order to determine the structures of the complexes,
X-ray quality crystals were obtained by slow evapora-
tion of CH2Cl2/hexane solutions at 4 °C and analyzed by
X-ray difraction analysis. The ORTEP views are shown in
Figs. 1, 2, and 3, and selected geometric data are listed in
Table 2. Complex 2 crystallizes in monoclinic space group
Fig. 1 ORTEP view of complex
2 with 50% probability level
ellipsoids. Hydrogen atoms
have been omitted for clarity
Fig. 2 ORTEP view of complex
3 with 50% probability level
ellipsoids. Hydrogen atoms
have been omitted for clarity
1 3

Transition Metal Chemistry
Fig. 3 ORTEP view of complex
4 with 50% probability level
ellipsoids. Hydrogen atoms
have been omitted for clarity
Table 2 Selected bond distances (Å) and angles (°) for the complexes
2–4
the phosphine-substituted Fe (1.756 Å) is shorter than that
of the unsubstituted Fe (1.784 Å), which can be attributed
to the phosphine ligand having stronger electron-donating
properties than CO [31]. The cyclohexyl rings of the tricy-
clohexylphosphine adopt a chair conformation in the crystal
structure.
Complex
2
3
4
Fe1–Fe2
Fe1–S1
Fe1–S2
Fe2–S1
Fe2–S2
Fe2–P1
S1–C6
S2–C7
2.4909(3)
2.2597(6)
2.2674(5)
2.2605(5)
2.2579(5)
2.2582(5)
1.826(2)
2.5093(4)
2.2471(6)
2.2500(7)
2.2473(6)
2.2467(6)
2.2005(6)
1.821(3)
2.5188(9)
2.2477(14)
2.2578(14)
2.2420(14)
2.2544(13)
2.2074(13)
1.832(6)
1.822(6)
1.530(9)
55.77(4)
79.75(5)
56.00(4)
55.98(4)
56.13(4)
79.94(5)
153.65(4)
68.25(4)
67.87(4)
112.6(4)
111.0(4)
Complex 3 crystallizes in orthorhombic space group Pbca
with eight molecules in the unit cell and one molecule in the
asymmetric unit. As shown in Fig. 2, similar to complex 2,
complex 3 contains a diiron cluster with a bridging ethane-
1,2-dithiolate ligand, plus fve terminal carbonyls and an
apically coordinated methyl diphenylphosphinite ligand. The
Fe1–Fe2 bond distance [2.5093(4) Å] is slightly longer than
that of complex 2, but shorter than some diiron complexes
with monophosphine [37] or diphosphine [38, 39] ligands.
Complex 4 crystallizes in triclinic space group P-1 with
two molecules in the unit cell and one molecule in the
asymmetric unit. As shown in Fig. 3, complex 4 consists
of a diiron cluster with a bridging ethane-1,2-dithiolate
ligand, plus fve terminal carbonyls and an apically coor-
dinated tris(2-thienyl)phosphine ligand. The Fe1–Fe2 bond
distance [2.5188(9) Å] is longer than those of complexes
2 and 3, suggesting that tris(2-thienyl)phosphine is more
electron donating than tricyclohexylphosphine and methyl
diphenylphosphinite.
1.817(2)
1.492(3)
1.825(3)
1.507(4)
C6–C7
S1–Fe1–Fe2
S1–Fe1–S2
S2–Fe1–Fe2
S1–Fe2–Fe1
S2–Fe2–Fe1
S2–Fe2–S1
P1–Fe2–Fe1
Fe1–S1–Fe2
Fe2–S2–Fe1
C7–C6–S1
C6–C7–S2
56.575(14)
79.291(19)
56.420(14)
56.545(15)
56.786(14)
79.47(2)
160.337(17)
66.880(16)
66.794(16)
112.58(14)
112.11(15)
56.063(17)
79.82(2)
56.017(17)
56.059(17)
56.144(18)
79.89(2)
149.14(2)
67.878(18)
67.839(19)
112.34(17)
112.01(17)
Electrochemical studies
of complex 1 [2.505(2) Å] [36], showing that the tricy-
clohexylphosphine ligand does not appreciably afect the
Fe–Fe bond. The Fe1–Fe2 bond distance is in fact nota-
bly shorter than that in natural [FeFe]-hydrogenases
(2.55–2.62 Å) [9, 10]. The average Fe–C bond distance of
The electrochemical properties of complexes 2–4 were
studied by CV in acetonitrile solution. The electrochemi-
cal data for the complexes 1–4 are listed in Table 3.
1 3

Transition Metal Chemistry
Table 3 Electrochemical data for the complexes 1–4
Complex
Epc1 (V)
Epc2 (V)
Epa (V)
1
2
3
4
−1.70
−1.97
−1.94
−1.88
−2.11
–
−2.20
−2.10
+0.88
+0.28
+0.42
+0.41
Fig. 5 Cyclic voltammogram of complex 3 (1.0 mM) with HOAc
(0–10 mM) in 0.1 M n-Bu4NPF6/MeCN at a scan rate of 100 mV s−1
Fig. 4 Cyclic voltammogram of complex 2 (1.0 mM) with HOAc
(0–10 mM) in 0.1 M n-Bu4NPF6/MeCN at a scan rate of 100 mV s−1
Complex 2 shows a single irreversible reduction peak
at − 1.97 V, which can be ascribed to the reduction of
FeIFeI to FeIFe0 [40]. This peak is shifted negatively by
0.27 V compared to the frst reduction process of com-
plex 1 (− 1.70 V), refecting the fact that the tricyclohex-
ylphosphine ligand is more strongly electron donating than
CO [31]. Meanwhile, complex 3 shows two irreversible
reduction peaks at − 1.94 and − 2.20 V; the second reduc-
tion can be ascribed to the reduction of FeIFe0 to Fe0Fe0
[40], again shifted to more negative potential compared
to complex 1 (− 2.11 V). Similarly, complex 4 shows two
reduction peaks at − 1.88 and − 2.10 V. In addition, com-
plexes 2–4 each show an irreversible oxidation at + 0.28,
+ 0.42, and + 0.41 V, respectively, which can be ascribed
to the oxidation of FeIFeI to FeIFeII [40]. These peaks are
negatively shifted by 0.46–0.60 V compared to complex
1, as observed previously for other phosphine-containing
diiron complexes [30, 34, 36].
Fig. 6 Cyclic voltammogram of complex 4 (1.0 mM) with HOAc
(0–10 mM) in 0.1 M n-Bu4NPF6/MeCN at a scan rate of 100 mV s−1
increase signifcantly with sequential addition of acetic
acid. The sharp increase in current intensity suggests an
electrocatalytic process for the reduction of protons to H2
[41, 42].
Conclusions
We further studied the electrocatalytic properties for
proton reduction to H2 catalyzed by complexes 2–4 in the
presence of acetic acid (0–10 mM). As shown in Figs. 4, 5,
and 6, upon addition of 2 mM acetic acid, the frst reduc-
tion peak is slightly increased but does not grow stead-
ily with sequential addition of more acid. However, new
reduction peaks at −2.13, −2.32, and −2.39 V appear and
In conclusion, we have presented the synthesis and charac-
terization of three diiron ethane-1,2-dithiolate complexes
with monosubstituted phosphine coligands. The X-ray
crystal structures of the complexes revealed that they con-
sist of a diiron core with a bridging ethane-1,2-dithiolate
ligand, fve terminal carbonyls, and an apically coordi-
nated phosphine ligand.
1 3

Transition Metal Chemistry
20. Song LC, Yan J, Li YL, Wang DF, Hu QM (2009) Inorg Chem
48:11376
Supplementary material
21. Capon JF, Hassnaoui SE, Gloaguen F, Schollhammer P, Talarmin
J (2005) Organometallics 24:2020
CCDC 1890166‒1890168 contain the supplementary crys-
tallographic data for this paper. These data can be obtained
free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
22. Winter A, Zsolnai L, Huttner G (1982) Z Naturforsch 37b:1430
23. Justice AK, Nilges MJ, Rauchfuss TB, Wilson SR, De Gioia L,
Zampella G (2008) J Am Chem Soc 130:5293
24. Olsen MT, Bruschi M, De Gioia L, Rauchfuss TB, Wilson SR
(2008) J Am Chem Soc 130:12021
Acknowledgements This research was supported by Zhejiang Provin-
cial Natural Science Foundation of China under Grant LY19B020002,
National Natural Science Foundation of China under Grant 21501124,
Science & Technology Department of Sichuan Province under Grant
2018JY0235, Education Department of Sichuan Province under Grant
18ZA0337, and Sichuan University of Science & Engineering under
Grant S201910622022.
25. APEX2, version 2009.7-0, Bruker AXS, Inc., Madison, 2007
26. Sheldrick GM (2001) SADABS: program for absorption correc-
tion of area detector frames. Bruker AXS Inc., Madison
27. Dolomanov OV, Bourhis LJ, Gildea RJ, Howard JAK, Puschmann
H (2009) J Appl Crystallogr 42:339
28. Sheldrick GM (2008) Acta Crystallogr A 64:112
29. Lian M, He J, Yu XY, Mu C, Liu XF, Li YL, Jiang ZQ (2018) J
Organomet Chem 870:90
30. Abul-Futouh H, Almazahreh LR, Harb MK, Görls H, El-khateeb
M, Weigand W (2017) Inorg Chem 56:10437
References
31. Zhao PH, Li XH, Liu YF, Liu YQ (2014) J Coord Chem 67:766
32. Li YL, He J, Wei J, Wei J, Mu C, Wu Y, Xie B, Zou LK, Wang Z,
Wu ML, Li HM, Gao F, Zhao PH (2017) Polyhedron 137:325
33. Chen FY, He J, Mu C, Liu XF, Li YL, Jiang ZQ, Wu HK (2019)
Polyhedron 160:74
1. Tard C, Pickett CJ (2009) Chem Rev 109:2245
2. Gloaguen F, Rauchfuss TB (2009) Chem Soc Rev 38:100
3. Lubitz W, Ogata H, Rüdiger O, Reijerse E (2014) Chem Rev
114:4081
34. Chen XQ, Liu XF, Jiang ZQ, Zhang YX, Li X, Tian XN, Liu XH
(2016) J Coord Chem 69:1439
4. Rauchfuss TB (2015) Acc Chem Res 48:2107
5. Li Y, Rauchfuss TB (2016) Chem Rev 116:7043
6. Cammack R (1999) Nature 397:214
35. Lu DT, He J, Yu XY, Liu XF, Li YL, Jiang ZQ (2018) Polyhedron
149:1
7. Lemon BJ, Peter JW (1999) Biochemistry 38:12969
8. Frey M (2002) ChemBioChem 3:153
36. Ortega-Alfaro MC, Hernández N, Cerna I, López-Cortéz JG,
Gómez E, Toscano RA, Alvarez-Toledano C (2004) J Organomet
Chem 689:885
9. Peters JW, Lanzilotta WN, Lemon BJ, Seefeldt LC (1998) Science
282:1853
37. He J, Deng CL, Li Y, Li YL, Wu Y, Zou LK, Mu C, Luo Q, Xie
B, Wei J, Hu JW, Zhao PH, Zheng W (2017) Organometallics
36:1322
10. Nicolet Y, Piras C, Legrand P, Hatchikian CE, Fontecilla-Camps
JC (1999) Structure 7:13
11. De Lacey AL, Stadler C, Cavazza C, Hatchikian EC, Fernandez
VM (2000) J Am Chem Soc 122:11232
38. Zhao PH, Ma ZY, Hu MY, He J, Wang YZ, Jing XB, Chen HY,
Wang Z, Li YL (2018) Organometallics 37:1280
39. Zhao PH, Hu MY, Li JR, Ma ZY, Wang YZ, He J, Li YL, Liu XF
(2019) Organometallics 38:385
12. Fan H, Hall MB (2001) J Am Chem Soc 123:3828
13. Berggren G, Adamska A, Lambertz C, Simmons TR, Esselborn J,
Atta M, Gambarelli S, Mouesca JM, Reijerse E, Lubitz W, Happe
T, Artero V, Fontecave M (2013) Nature 499:66
14. Lawrence JD, Li H, Rauchfuss TB (2001) Chem Commun 1482
15. Li H, Rauchfuss TB (2002) J Am Chem Soc 124:726
16. Lawrence JD, Li H, Rauchfuss TB, Bénard M, Rohmer MM
(2001) Angew Chem Int Ed 40:1768
40. Song LC, Ge JH, Zhang XG, Liu Y, Hu QM (2006) Eur J Inorg
Chem 2006:3204
41. Gloaguen F, Lawrence JD, Rauchfuss TB (2001) J Am Chem Soc
123:9476
42. Chong D, Georgakaki IP, Mejia-Rodriguez R, Sanabria-Chinchilla
J, Soriaga MP, Darensbourg MY (2003) Dalton Trans 4158
17. Ott S, Kritikos M, Åkermark B, Sun L, Lomoth R (2004) Angew
Chem Int Ed 43:1006
Publisher’s Note Springer Nature remains neutral with regard to
jurisdictional claims in published maps and institutional afliations.
18. Lyon EJ, Georgakaki IP, Reibenspies JH, Darensbourg MY (2001)
J Am Chem Soc 123:3268
19. Li P, Wang M, He C, Li G, Liu X, Chen C, Åkermark B, Sun L
(2005) Eur J Inorg Chem 2005:2506
1 3