Syntheses of new Fe/S clusters via reactions of Fe3(CO) 12 and salts of heteroallyl anions of type [GCS2] - (G = Ph2PS, ArCOCH2, 2-C5H 4NNH and 2-C3H2<

Article abstract of DOI:10.1016/j.poly.2013.03.049

The reaction of Fe₃(CO)₁₂ and [NEt ₄][GCS₂] with an electrophile CH₃I in THF affords complex Fe₂(CO)₆(μ-GC(S)SCH₃) (G = Ph₂PS, 1). The reaction of Fe_3<

Full text of DOI:10.1016/j.poly.2013.03.049

Polyhedron 56 (2013) 160–171
Contents lists available at SciVerse ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Syntheses of new Fe/S clusters via reactions of Fe3(CO)12 and salts of
heteroallyl anions of type [GCS2]ꢀ (G = Ph2PS, ArCOCH2, 2-C5H4NNH and
2-C3H2NSNH) with electrophiles
⇑
Yao-Cheng Shi , Huan-Ren Cheng, Qiang Fu, Fei Gu, Yan-Hua Wu
College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China
a r t i c l e i n f o
a b s t r a c t
Article history:
The reaction of Fe3(CO)12 and [NEt4][GCS2] with an electrophile CH3I in THF affords complex Fe2(CO)6(l-
Received 26 November 2012
Accepted 19 March 2013
Available online 3 April 2013
GC(S)SCH3) (G = Ph2PS, 1). The reaction of Fe3(CO)12 with PhCOCH2CS2H and NEt3 forms a red-brown solu-
tion of [HNEt3][Fe2(CO)6( -GCS2)] identified by IR and ESI-MS (G = PhCOCH2). The reactions of the solution
with a series of electrophiles E–X such as CH3I, PhCH2Br and CH2@CHCH2Br produce complexes Fe2(CO)6
-GC(S)SE) (2, E = CH3; 3, E = CH2Ph; 4, E = CH2CH@CH2). In the absence of NEt3, the reaction of Fe3(CO)12
and PhCOCH2CS2H gives complex Fe2(CO)6( -S2C@CHCOPh) (5). The reaction of GCS2H with NEt3, Fe3
(CO)12 and CH3I yields complexes Fe2(CO)6( -GC(S)SCH3) (G = 4-MeOC6H4COCH2, 6; G = C5H5FeC5H4-
COCH2, 7). The reaction of Fe(C5H4COCH2CS2H)2, NEt3 and Fe3(CO)12 with CH3I affords complex Fe[( -C5-
l
(
l
Keywords:
l
Iron carbonyl
Iron–iron bond
Dithiocarboxylic acid
Heteroallyl anion
Hydrogenase
Synthesis
l
l
H4COCH2C(S)SCH3)Fe2(CO)6]2 (8). Unlike the above-mentioned cases, the reaction of Fe3(CO)12 and
[HNEt3][GCS2] (G = 2-C5H4NNH, 2-C3H2NSNH) with PhCOCl generates the corresponding complexes Fe2
(CO)5(
CS)(
l l l
-k2N,S:k2C-2-C5H4NN(COPh)CS)( -k2S-SCOPh) (9) and Fe2(CO)5( -k2N,S:k2C-2-C3H2NSN(COPh)
l
-k2S-SCOPh) (10). All new complexes have been characterized by elemental analysis, IR, 1H and 13
C
NMR spectroscopy as well as 31P NMR spectroscopy for 1, structures of them have been unequivocally
determined by X-ray crystallography.
Ó 2013 Elsevier Ltd. All rights reserved.
1. Introduction
reactivity. With the exception of the O-alkylation of the
l-CO
ligand by [Et3O][BF4], all reactions of the [( -RS)(
l
l
-CO)Fe2(CO)6]ꢀ
Fe/S cluster complexes have recently attracted considerable
attention, because of their interesting chemistry and particularly
their application in bionics as models for the active site of [Fe–
Fe] hydrogenases [1–3]. For this reason, reactions of organic thiols
RSH with iron carbonyls are of great significance [4]. In general,
anions can be rationalized in terms of their action as iron-
centered nucleophiles. For instance, reactions with a series of
three-electron electrophiles E–X such as PhCOCl, CH3COCl, CH2-
@CHCH2X, HC„CCH2X, Me2NC(S)Cl, Ph2PCl and EtSCl provide
neutral diiron products of type [( -RS)(l-E)Fe2(CO)6] in which
l
such reactions form butterfly complexes of type (
[5]. However, reactions of secondary and tertiary thiols RSH with
Fe3(CO)12 afford triiron products of type [Fe3(CO)9( 3-SR)( -H)]
[6,7]. Such complexes can be deprotonated with a tertiary amine
l
-RS)2Fe2(CO)6
the organic group E replaces the l-CO ligand of the anion as a
bridging group [14,15]. Interestingly, reactions of dithioacids
ArCOCH2CS2H, which can isomerize to ArCOCH@C(SH)2 and
ArC(OH)@CHCS2H, with Fe3(CO)12 in THF and with Fe2(CO)9 in
l
l
and the resulting anions of type [Fe3(CO)9(
l
3-SR)]ꢀ react with a
Et2O produce complexes of Fe2(CO)6(l-S2C@CHCOAr) (Ar = 4-
variety of electrophiles, for instance, R02PC1, R02AsC1, R0PCl2 and
C12, to give new Fe3(CO)9 cluster complexes [8,9]. Reactions of so-
dium alkanethiolates RSNa with Fe3(CO)12 in refluxing THF also
FC6H4, 4-MeOC6H4) and Fe2(CO)6( -S2CHCH2COAr) (Ar = 4-BrC6H4,
l
4-ClC6H4, 4-MeC6H4, 4-MeOC6H4), respectively [16,17]. In view of
no reports on heteroallyl anions of type G-C(@Y)-Zꢀ (G = potential
donor group; Y = S, Se; Z = S, Se, NR, CHR) with iron carbonyls, we
have initiated the project on reactions of heteroallyl anions of
type G-C(@Y)-Zꢀ with iron carbonyls to develop the synthetic
methodology of Fe cluster complexes. As part of the ongoing pro-
ject, herein we report that reactions of Fe3(CO)12 and salts of het-
eroallyl anions of type [GCS2]ꢀ (G = Ph2PS, ArCOCH2, 2-C5H4NNH
and 2-C3H2NSNH) with electrophiles [18,19].
produce anions of type [Fe3(CO)9(
l
3-SR)]ꢀ, upon acidification
l-H)] are generated [10]. In
complexes of type [Fe3(CO)9( 3-SR)(
l
contrast, reactions of thiols RSH with Fe3(CO)12 in the presence
of base such as Et3N at room temperature yield anions of type
[(l-RS)(l
-CO)Fe2(CO)6]ꢀ [11–13]. These anions have ambident
⇑
Corresponding author. Tel.: +86 0514 87857939; fax: +86 0514 87857939.
E-mail address: ycshi@yzu.edu.cn (Y.-C. Shi).
0277-5387/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.poly.2013.03.049

Y.-C. Shi et al. / Polyhedron 56 (2013) 160–171
161
1957 (s);
m
(C@O) 1673 (m) cmꢀ1
.
1H NMR (300 MHz, CDCl3,
2. Experimental
TMS): 2.26 (s, 3H, CH3), 3.15, 3.60 (dd, AB type, 1H, 1H,
2JH–H = 17.4 Hz, CH2), 7.47–7.88 (3m, 5H, C6H5) ppm. 13C NMR
(75.5 MHz, CDCl3, TMS): 32.8 (CH3), 54.2 (CH2), 67.3 (CS2), 128.1,
128.8, 133.7, 136.3 (C6H5), 195.1 (C@O), 211.1 (s, 6C„O) ppm.
13C NMR (100.65 MHz, CDCl3): 32.66 (CH3), 54.01 (CH2), 67.33
(CS2), 128.00, 128.77, 133.71, 136.13 (C6H5), 195.07 (C@O),
210.94, 211.01, 211.11, 211.18, 211.23, 211.28 (6s, 6C„O) ppm.
2.1. General comments
All reactions were carried out under a prepurified N2 atmo-
sphere with standard Schlenk techniques. All solvents employed
were dried by refluxing over appropriate drying agents and stored
under an N2 atmosphere. THF was distilled from sodium-
benzophenone, petroleum ether (60–90 °C) and CH2Cl2 from
P2O5. Fe3(CO)12 [20], [NEt4][Ph2PSCS2] [21], PhCOCH2CS2H
[22,23], 4-MeOC6H4COCH2CS2H [22,23], C5H5FeC5H4COCH2CS2H
[24], Fe(C5H4COCH2CS2H)2 [24] and [HNEt3][G0NHCS2] (G0 = 2-pyr-
idyl group, 2-C5H4N; G0 = 2-thiazyl group, 2-C3H2NS) [25–27] were
prepared according to literature procedures. The progress of all
reactions was monitored by TLC (silica gel H). NMR spectra were
carried out on a Bruker Avance 600 or 500 or 400 or 300 spectrom-
eter. ESI-MS data were recorded on a Bruker Maxis spectrometer.
IR spectra were recorded on a Bruker Tensor 27 spectrometer as
KBr disks in the range 400-4000 cmꢀ1. Analyses for C, H and N
were performed on a PE 2400 Series III instrument. Melting points
were measured on a Yanagimoto apparatus and uncorrected.
2.4. Synthesis of complex 3
The same procedure, but PhCH2Br was the added electrophile,
afforded an orange solid of 3 (0.630 g), mp, 154–156 °C, in 56%
yield. Anal. Calc. for C22H14Fe2O7S2: C, 46.67; H, 2.49. Found: C,
46.84; H, 2.13%. IR (KBr disk):
m(C„O) 2069 (s), 1986 (vs, br),
1928 (s);
m
(C@O) 1688 (m) cmꢀ1
.
1H NMR (300 MHz, CDCl3,
2
TMS): 2.79, 3.67 (dd, AB type, 1H, 1H, JH–H = 18.6 Hz, CH2), 3.71,
2
4.01 (dd, AB type, 1H, 1H, JH–H = 13.5 Hz, CH2), 6.92–7.17, 7.33–
7.55 (m, 5H, m, 5H, 2C6H5) ppm. 13C NMR (75.5 MHz, CDCl3,
TMS): 54.4 (CH2), 56.4 (CH2), 68.5 (CS2), 127.6, 127.9, 128.3,
128.4, 128.9, 133.3, 134.3, 135.9 (2C6H5), 194.2 (C@O), 211.1 (s,
6C„O) ppm.
2.2. Synthesis of complex 1
2.5. Synthesis of complex 4
A 50-mL Schlenk flask equipped with a stir bar and serum cap
was charged with 1.007 g (2 mmol) of Fe3(CO)12, 0.847 g (2 mmol)
of [NEt4][SPPh2CS2] and 25 mL of THF. The mixture was stirred for
2 h at 0 °C to form a red-brown solution. To this solution was
added an excess of an electrophile (MeI, 0.426 g, 3 mmol). The
solution was stirred for 12 h at room temperature. After the sol-
vent was removed under reduced pressure, the resulting residue
was subjected to TLC (silica gel). Elution with petroleum ether
(60–90 °C) and CH2Cl2 (3:1, v/v) gave an orange band which was
recrystallized from deoxygenated petroleum ether and CH2Cl2 to
afford an orange-red solid of 1 (0.682 g), mp, 146–148 °C, in 60%
yield. Anal. Calc for C20H13Fe2O6PS3: C, 40.84; H, 2.23. Found: C,
The same procedure, but CH2@CHCH2Br was the added electro-
phile, gave an orange solid of 4 (0.588 g), mp, 110–112 °C, in 57%
yield. Anal. Calc. for C18H12Fe2O7S2: C, 41.89; H, 2.34. Found: C,
41.56; H, 2.44%. IR (KBr disk):
m
.
(C„O) 2069 (s), 2021 (vs), 1995
(s, sh);
m
(C@O) 1689 (m) cmꢀ1
1H NMR (600 MHz, CDCl3, TMS):
3.09–3.14 (m, 2H, SCH2), 3.47–3.50 (q, 1H), 3.80–3.83 (d, 1H,
2JH–H = 18 Hz), 5.14–5.15 (d, 1H, JH–H = 6 Hz), 5.25ꢀ5.28 (d, 1H,
2JH–H = 18 Hz), 5.69–5.75 (m, 1H), 7.44–7.46, 7.56–7.59, 7.82–7.84
(t, 2H, t, 1H, d, 2H, C6H5) ppm. 13C NMR (150.9 MHz, CDCl3,
TMS): 52.6 (CH2), 54.7 (CH2), 67.0 (CS2), 121.6, 127.8, 128.8,
129.9, 133.7, 136.1 (CH2@CH, C6H5), 194.8 (C@O), 211.2 (s,
6C„O) ppm.
40.84; H, 2.21%. IR (KBr disk):
m(C„O) 2067 (s), 2000 (vs, br),
1957 (s) cmꢀ1 1H NMR (300 MHz, CDCl3, TMS): 1.47 (s, 3H, CH3),
.
2.6. Synthesis of complex 5
7.42–7.60, 7.82–7.86, 8.14–8.19 (3m, 6H, 2H, 2H, 2C6H5) ppm.
31P NMR (121.6 MHz, CDCl3, 85% H3PO4): 55.8 (s) ppm. 13C NMR
(75.5 MHz, CDCl3, TMS): 35.2 (CH3), 128.5 (1JC–P = 12.5 Hz, CS2),
129.1 (1JC–P = 12.3 Hz), 132.0, 132.2, 132.3 (2C6H5), 210.2 (s,
6C„O) ppm.
A 50-mL Schlenk flask equipped with a stir bar and serum cap
was charged with 1.007 g (2 mmol) of Fe3(CO)12, 0.393 g (2 mmol)
of PhCOCH2CS2H and 25 mL of THF. The mixture was stirred for 1 h
at room temperature. After removal of the solvent in vacuo, the
resulting residue was subjected to TLC (silica gel). Petroleum ether
(60–90 °C) and CH3COCH3 (20:1, v/v) eluted an orange band which
provided an orange solid of 5 (0.398 g), mp, 104–106 °C, in 42%
yield. Anal. Calc. for C15H6Fe2O7S2: C, 38.01; H, 1.28. Found: C,
2.3. Synthesis of complex 2
A 50-mL Schlenk flask equipped with a stir bar and serum cap
was charged with 1.007 g (2 mmol) of Fe3(CO)12, 0.393 g (2 mmol)
of PhCOCH2CS2H and 25 mL of THF and cooled to 0 °C. After the
addition of 0.221 g (2.18 mmol) NEt3, the mixture was stirred for
2 h at the same temperature to form a red-brown solution (when
cooled to ꢀ78 °C, a brown solid is obtained, which is formulated
38.41; H, 1.43%. IR (KBr disk):
m
(C„O) 2082 (s), 2043 (vs), 2000
(vs);
m
(C@O) 1651 (m) cmꢀ1
.
1H NMR (600 MHz, CDCl3, TMS):
6.51 (s, 1H, CH), 7.44–7.46, 7.54–7.57, 7.82–7.83 (t, 2H, t, 1H, d,
2H, C6H5) ppm. 13C NMR (150.9 MHz, CDCl3, TMS): 111.0 (CH),
128.0, 128.7, 133.3, 137.6 (C6H5), 167.4 (CS2), 188.1 (C@O), 207.1
(s, 6C„O) ppm.
as [HNEt3][Fe2(CO)6(l-PhCOCH2CS2)] and characterized both by
IR which shows that the terminal carbonyl ligands appear as three
strong absorptions at 1970, 2002 and 2044 cmꢀ1 and the ketonic
C@O group as one medium absorption at 1684 cmꢀ1 and by ESI-
MS which indicates that Fe2(CO)6(PhCOCH2CS2) appears at
m/z = 474.8336 and Et3NH at m/z = 102.1276). To this solution
was added an excess amount of MeI (0.426 g, 3 mmol). The solu-
tion was stirred for 12 h at room temperature. After removal of
the solvent under vacuum, the resulting residue was subjected to
TLC (silica gel). Petroleum ether (60–90 °C) eluted an orange band
which provided an orange solid of 2 (0.612 g), mp, 96–98 °C, in 62%
yield. Anal. Calc. for C16H10Fe2O7S2: C, 39.21; H, 2.06. Found: C,
2.7. Synthesis of complex 6
The same procedure as 2, but 4-MeOC6H4COCH2CS2H was the
added dithioacid, afforded an orange solid of 6 (0.582 g), mp,
144–146 °C, in 58% yield. Anal. Calc. for C17H12Fe2O8S2: C, 39.26;
H, 2.33. Found: C, 39.41; H, 1.93%. IR (KBr disk):
(vs), 2013 (vs), 1945 (s);
m
(C„O) 2068
.
m
(C@O) 1670 (m) cmꢀ1
1H NMR
(300 MHz, CD3COCD3, TMS): 2.47 (s, 3H, SCH3), 3.88 (s, 3H,
2
OCH3), 3.11, 3.99 (dd, AB type, 1H, 1H, JH–H = 18.1 Hz, CH2),
7.00–7.03, 7.92–7.95 (d, 2H, d, 2H, C6H4) ppm. 13C NMR
(75.5 MHz, CD3COCD3, TMS): 32.9 (SCH3), 53.8 (OCH3), 56.1
39.38; H, 1.64%. IR (KBr disk):
m(C„O) 2061 (s), 1999 (vs, br),

162
Y.-C. Shi et al. / Polyhedron 56 (2013) 160–171
(CH2), 70.9 (CS2), 114.8, 132.4 (C6H4), 194.2 (C@O), 212.8 (s, 6C„O)
ppm.
(m), 1663 (m) cmꢀ1
.
1H NMR (500 MHz, CDCl3, TMS): 7.41–7.77
3
(3m, 10H, 2C6H5), 7.90, 7.96 (dd, JH–H = 7 Hz, 2H, 2-C3H2NS)
ppm. 13C NMR (125.8 MHz, CDCl3, TMS): 114.8, 128.7, 128.9,
129.2, 129.9, 130.2, 132.9, 133.0, 134.3, 136.1, 139.6 (2C6H5, 2-
C3H2NS), 164.9 (C@O), 169.3 (C@O), 198.5 (CS), 205.9, 206.3,
212.4, 212.9, 213.7 (C„O) ppm.
2.8. Synthesis of complex 7
The same procedure, but C5H5FeC5H4COCH2CS2H (0.608 g,
2 mmol) was the added dithioacid, provided a red-brown solid of
7 (0.430 g), mp, 107–109 °C, in 36% yield. Anal. Calc. for C20H14Fe3-
O7S2: C, 40.17; H, 2.36. Found: C, 40.30; H, 2.02%. IR (KBr disk):
2.12. X-ray structure determinations of 1–10
m
(C@O) 2067 (s), 2024 (vs, br), 1956 (s); m .
(C@O) 1665 (m) cmꢀ1
Single crystals of 1–10 suitable for X-ray diffraction analyses
were grown by slow evaporation of the CH2Cl2-petroleum ether
solutions at 0–4 °C. For each of complexes, a selected single crystal
was mounted on a Bruker APEX II CCD diffractometer using graph-
1H NMR (500 MHz, CDCl3, TMS): 2.27 (s, 3H, CH3), 2.92, 3.39 (dd,
2
AB type, 1H, 1H, JH–H = 17.5 Hz, CH2), 4.18 (s, 5H, C5H5), 4.54,
4.72–4.76 (s, 2H, d, 2H, C5H4) ppm. 13C NMR (125.8 MHz, CDCl3,
TMS): 33.5 (CH3), 56.6 (CH2), 67.2 (CS2), 69.2 (C5H5), 69.6, 70.0,
72.8 (C5H4), 199.0 (C@O), 211.5 (s, 6C„O) ppm.
ite-monochromated Mo Ka radiation (k = 0.71073 Å) at 296 K. Data
collection and reduction were performed using the SAINT software
[28]. An empirical absorption correction was applied using the SAD-
ABS program [29]. The structures were solved by direct methods
using a SIR-2004 software and refined by full-matrix least-squares
based on F2 with anisotropic thermal parameters for all non-hydro-
gen using SHELXTL package of programs [30,31]. All H atoms in 1–10
were placed at geometrically idealized positions and subsequently
treated as riding atoms, with C–H = 0.93 (aromatic, olefinic), 0.97
(CH2) and 0.96 (CH3) Å and Uiso(H) values of 1.2Ueq(C) or
1.5Ueq(Cmethyl). ORTEP plots of complexes are drawn using a WINGX soft-
ware [32]. Details of crystal data, data collections and structure
refinements are summarized in Table 1 for 1–5 and Table 2 for 6–10.
2.9. Synthesis of complex 8
The same procedure, but Fe(C5H4COCH2CS2H)2 (0.422 g,
1 mmol) was used in place of C5H5FeC5H4COCH2CS2H, afforded a
red-brown solid of 8 (0.400 g), mp, 144–146 °C, in 20% yield. Anal.
Calc. for C30H18Fe5O14S4: C, 35.68; H, 1.80. Found: C, 35.82; H,
1.39%. IR (KBr disk):
m
m(C„O) 2034 (s), 1969 (vs, br), 1907 (s);
.
(C@O) 1659 (m) cmꢀ1
1H NMR (300 MHz, CD3COCD3, TMS):
2
2.59 (s, 6H, 2SCH3), 2.86, 3.82 (dd, AB type, 2H, 2H, JH–H = 18.6
Hz, 2CH2), 4.63, 4.82 (s, 4H, s, 4H, 2C5H4) ppm. 13C NMR
(75.5 MHz, CD3COCD3, TMS): 33.4 (CH3), 55.5 (CH2), 70.7 (CS2),
71.7 (C5H5), 72.0, 74.6, 74.8 (C5H4), 198.9 (C@O), 212.8 (s, 6C„O)
ppm.
3. Results and discussion
2.10. Synthesis of complex 9
3.1. Syntheses of complexes
A 50-mL Schlenk flask equipped with a stir bar and serum cap
The mixture of [NEt4][Ph2P(@S)CS2] and Fe3(CO)12 in THF is stir-
red for 2 h at 0 °C to give a red-brown solution [18,19]. The resulting
solution reacts in situ with an electrophile E–X (CH3I) to afford an or-
ange complex 1 in good yield (Eq. 1). According to an X-ray diffrac-
was charged with 0.756 g (1.5 mmol) of Fe3(CO)12
, 0.407 g
(1.5 mmol) of [HNEt3][2-C5H4NNHCS2] and 30 mL of THF. The mix-
ture was stirred for 3 h at room temperature to form a red-brown
solution. To this solution was added 0.422 g (3 mmol) of PhCOCl.
The resulting solution was stirred for 24 h at room temperature.
After the solvent was removed under reduced pressure, the result-
ing residue was subjected to TLC (silica gel). Elution with petro-
leum ether (60–90 °C) and CH2Cl2 (4:1, v/v) gave one major band
which was recrystallized from deoxygenated petroleum ether
and CH2Cl2 to afford a dark-brown solid of 9 (0.397 g), mp, 178–
180 °C, in 42% yield. Anal. Calc. for C25H14Fe2N2O7S2: C, 47.65; H,
2.24; N, 4.45. Found: C, 47.93; H, 1.97; 4.44%. IR (KBr disk):
tion analysis of 1, cluster anions of type [Fe2(CO)6(l
-GCS2)]ꢀ (M),
are proposed as active intermediates (Scheme 1). In order to extend
the chemistry of M, the reaction of Fe3(CO)12 with [HNEt3][PhC-
OCH2CS2] generated in situ from PhCOCH2CS2H and NEt3 in THF is
undertaken [33–35]. When the solution is cooled to ꢀ78 °C, the
red-brown solid [HNEt3][Fe2(CO)6(l-GCS2)] (G = PhCOCH2) is
formed. This air-sensitive solid has been characterized by the fol-
lowing spectroscopies. The IR spectroscopy shows that the terminal
carbonyl ligands appear as three strong absorptions at 1970, 2002
and 2044 cmꢀ1 and the ketonic C@O group as one medium absorp-
tion at 1684 cmꢀ1. The ESI-MS indicates that Fe2(CO)6(PhCOCH2CS2)
occurs at m/z = 474.8336 and HNEt3 at m/z = 102.1276. Further-
m
(C„O) 2069 (s), 2007(vs), 1963 (vs);
m(C@O) 1708 (m), 1665
(m) cmꢀ1
.
1H NMR (500 MHz, CDCl3, TMS): 7.42–7.67 (m, 10H,
2C6H5), 7.91–8.05 (m, 4H, C5H4N) ppm. 13C NMR (125.8 MHz,
CDCl3, TMS): 112.3, 118.1, 128.6, 129.1, 129.3, 130.0, 130.9,
133.0, 134.1, 134.2, 136.4, 137.5, 153.8 (2C6H5, 2-C5H4N), 158.4
(C@O), 171.5 (C@O), 198.7 (CS), 206.9, 212.8, 213.6 (C„O) ppm.
more, [HNEt3][Fe2(CO)6(
trophile E–X such as CH3I, PhCH2Br and CH2@CHCH2Br to produce
orange complexes [Fe2(CO)6( -PhCOCH2CS2E)] (2, E = CH3; 3,
l-PhCOCH2CS2)] reacts in situ with an elec-
l
E = CH2Ph; 4, E = CH2CH@CH2) (Scheme 2). Therefore, this new
methodology is firmly established. Notably, the reaction of
Fe3(CO)12 or Fe2(CO)9 with PhCOCH2CS2H in the absence of NEt3 in
2.11. Synthesis of complex 10
A 50-mL Schlenk flask equipped with a stir bar and serum cap
was charged with 1.007 g (2 mmol) of Fe3(CO)12, 0.491 g (2 mmol)
of [HNEt3][2-C3H2NSNHCS2] and 30 mL of THF. The mixture was
stirred for 3 h at room temperature to form a red-brown solution.
To this solution was added 0.562 g (4 mmol) of PhCOCl. The result-
ing solution was stirred for 24 h at room temperature. After the
solvent was removed in vacuo, the resulting residue was subjected
to TLC (silica gel). Elution with petroleum ether and CH2Cl2 (1:1,
v/v) provided one major band which gave a dark-brown solid of
10 (0.573 g), mp, >360 °C, in 45% yield. Anal. Calc. for C23H12Fe2N2-
O7S3: C, 43.42; H, 1.90; N, 4.40. Found: C, 43.10; H, 1.81; N, 4.33%.
THF at room temperature yields an orange complex (l-PhC-
OCH@CS2)Fe2(CO)6 (5) and a side product S2Fe3(CO)9 [16,17]. How-
ever, 5 as a by-product is also generated in ca. 15% yield from the
reaction of Fe3(CO)12 with PhCOCH2CS2H and NEt3 in THF. Similarly,
the reaction of Fe3(CO)12, 4-MeOC6H4COCH2CS2H and NEt3 with
CH3I gives an orange complex 6 (Scheme 3). Interestingly, the reac-
tion of C5H5FeC5H4COCH2CS2H, NEt3 and Fe3(CO)12 with CH3I af-
fords a red-brown complex 7. In fact, except 5, these complexes
may be viewed as Fe2(CO)6 complexes of dithioacid esters of type
GCS2E. The complexes of type Fe2(CO)6(
CH2CH@CH2 and CH2COCH3) have been synthesized via the
Fe2(CO)6( -S)2CH2/LDA/R-X reaction sequence by Seyferth et al.
l-HCS2R) (R = Me, Et, CH2Ph,
IR (KBr disk):
m(C„O) 2061 (s), 2002 (vs), 1953 (s);
m(C@O) 1684
l

Y.-C. Shi et al. / Polyhedron 56 (2013) 160–171
163
Table 1
Crystal data and structure refinements for 1–5
1
2
3
4
5
Formula
Mr
C
20H13Fe2O6PS3
C16H10Fe2O7S2
490.08
C22H14Fe2O7S2
566.17
C18H12Fe2O7S2
516.12
C15H6Fe2O7S2
474.04
588.18
Crystal system
Space group
Monoclinic
P21/c
Monoclinic
P21/c
Monoclinic
P21/c
Triclinic
P1
Triclinic
P1
ꢀ
ꢀ
Unit cell dimensions
a (Å)
b (Å)
c (Å)
10.2367(4)
20.5928(15)
11.4028(11)
90
102.6923(14)
90
2345.0(3)
4
1.666
13.535(3)
12.169(2)
12.172(2)
90
106.439(2)
90
1922.9(6)
4
1.693
9.4551(14)
24.9746(16)
11.9135(14)
90
125.508(2)
90
2290.1(5)
4
1.642
9.4085(12)
10.196(2)
11.5406(13)
100.8749(16)
109.666(4)
93.385(2)
1014.8(3)
2
6.4205(9)
7.7079(10)
18.892(3)
83.5465(14)
82.8080(16)
76.8723(16)
899.9(2)
2
a
(°)
b (°)
c
(°)
V (Å3)
Z
Dc (g cmꢀ3
)
1.689
1.672
1.750
1.877
l
(mmꢀ1
)
1.607
1.760
1.490
F(000)
1184
984
1144
520
472
Index ranges
ꢀ12 6 h 6 13
ꢀ26 6 k 6 25
ꢀ146l 6 14
20167
ꢀ14 6 h 6 17
ꢀ15 6 k 6 15
ꢀ15 6 l 6 15
11644
ꢀ11 6 h 6 12
ꢀ32 6 k 6 32
ꢀ15 6 l 6 15
18735
ꢀ12 6 h 6 12
ꢀ9 6 k 6 13
ꢀ13 6 l 6 14
6478
ꢀ8 6 h 6 8
ꢀ9 6 k 6 9
ꢀ24 6 l624
7891
Reflections measured
Unique reflections
5387
4287
5261
4399
4031
Reflections (I > 2r(I))
4591
3552
4396
3876
3427
Independent reflections (Rint
)
0.0499
0.0271
0.0736
0.0242
0.0416
2hmax (°)
55.06
54.88
55.18
55.10
54.90
Data/restraints/parameters
R1
5387/0/290
0.0320
4287/0/245
0.0304
5261/0/299
0.0531
4399/0/262
0.0375
4031/0/235
0.0355
wR2
0.0839
0.0768
0.1442
0.1181
0.0996
Goodness-of-fit (GOF)
1.05
0.37 and ꢀ0.52
1.09
0.33 and ꢀ0.28
1.06
1.13 and ꢀ0.60
1.08
0.61 and ꢀ0.60
1.08
0.40 and ꢀ0.49
Largest diff peak and hole (e Åꢀ3
)
Table 2
Crystal data and structure refinements for 6–10
6
7
8
9
10
Formula
Mr
C
17H12Fe2O8S2
C20H14Fe3O7S2
1094.90
C30H18Fe5O14S4ꢁCH2Cl2
630.22
C25H14Fe2N2O7S2
636.26
C23H12Fe2N2O7S3
598.00
520.11
Crystal system
Space group
a (Å)
b (Å)
c (Å)
triclinic
triclinic
triclinic
monoclinic
P21/c
9.6572(13)
27.5152(15)
13.4486(13)
90
132.3600(10)
90
2640.6(5)
4
monoclinic
P 21/c
13.9769(13)
10.1673(10)
17.7971(17)
90
92.7272(11)
90
2526.2(4)
4
ꢀ
ꢀ
ꢀ
P1
P1
P1
8.5446(15)
11.0896(12)
12.5605(14)
67.6236(11)
71.6757(12)
76.7429(12)
1036.6(2)
2
9.9597(14)
13.779(2)
16.842(2)
79.9814(14)
88.3595(11)
87.9915(19)
2274.1(5)
4
13.4793(13)
13.5227(15)
13.7259(11)
73.0054(12)
65.7957(14)
65.7196(14)
2057.0(3)
2
a
(°)
b (°)
c
(°)
V (Å3)
Z
Dc (g cmꢀ3
)
1.666
1.641
1.747
2.111
1.768
2.116
1.585
1.304
1.673
1.443
l
(mmꢀ1
)
F(000)
524
1200
1092
1272
1280
Index ranges
ꢀ116h611
ꢀ146k614
ꢀ166l616
8990
ꢀ126h612
ꢀ176k617
ꢀ216l621
20066
ꢀ176h617
ꢀ176k617
ꢀ176l617
17882
ꢀ126h611
ꢀ356k635
ꢀ176l615
23220
ꢀ176h618
ꢀ136k613
ꢀ226l623
21513
Reflections measured
Unique reflections
4602
10314
9194
6099
5785
Reflections (I > 2r(I))
3897
7430
4218
3586
4765
Rint
0.0229
0.0283
0.0535
0.0692
0.0302
2hmax (°)
54.76
55.34
55.02
55.16
55.06
Data/restraints/parameters
R1
4602/13/265
0.0378
10314/0/579
0.0356
9194/0/507
0.0640
6099/0/343
0.0460
5785/0/334
0.0265
wR2
0.1221
0.1033
0.1996
0.1032
0.0781
Goodness-of-fit (GOF)
1.06
1.34 and ꢀ0.55
0.95
0.50 and ꢀ0.34
0.95
0.94 and ꢀ0.85
0.98
0.34 and ꢀ0.31
1.03
0.24 and ꢀ0.35
Largest diff peak and hole (e Åꢀ3
)
[36,37]. Moreover, the complexes of dithioesters of type R0CS2R have
been prepared by Patin and coworkers via reactions of dithioesters
such as PhCS2Me and 2-C4H3SCS2Me with Fe2(CO)9 [38–40]. Even so,
the easy availability of the starting materials and the high clarity of
the mechanism render this new approach remarkably promising. As
expected, this new methodology can also be applied to tetrathiodi-
carboxylic acids such as Fe(C5H4COCH2CS2H)2. Thus, a red-brown
bis(Fe2(CO)6) complex 8 is obtained (Eq. 2).
Very recently, the novel chemistry of Fe2(CO)6(
pared from the reaction of Fe3(CO)12 and [NEt4][Ph2PCS2] has been
l
-Ph2PCS2ꢀ) pre-

164
Y.-C. Shi et al. / Polyhedron 56 (2013) 160–171
COPh
S
(OC)3Fe
Me-S
Fe(CO)3
1. Fe3(CO)12
2. MeI
+
Ph2P(=S)CS2-NEt4
S-
(OC)3Fe
G'NH
Fe(CO)3
S
C
PhCOCl
(OC)2Fe
G'NH
Fe(CO)3
S
(OC)2Fe
Fe(CO)3
Ph2P=S
(1)
C
S
S-
C
C
G'N
S
Eq. 1. Synthesis of complex 1.
(M')
COPh
Fe3(CO)12
(9-10)
-
GCS2
(OC)3Fe
S
Fe(CO)3
(OC)3Fe
Fe(CO)3
Fe3(CO)12
Scheme 4. Syntheses of complexes 9 and 10 (G0 = 2-C5H4N, 9; G0 = 2-C3H2NS, 10).
E-X
- X-
-
GCS2
C
S
S
C
E-S
(Scheme 4). With a view to broadening the chemistry of M0, the
reaction of Fe3(CO)12 and [HNEt3][2-C3H2NSNHCS2] is also per-
G
G
(M)
Scheme 1. Formation of [Fe2(CO)6(l
-GCS2)]ꢀ (M) and reaction of M with electro-
phile E–X (G = Ph2PS, ArCOCH2).
formed. Convincingly, the brown solution of [HNEt3][Fe2(CO)5(
l-
GCS)(l
-Sꢀ)] (G = 2-C3H2NSNH, G0 = 2-C3H2NS) reacts with PhCOCl
to afford a dark-brown complex 10. On the basis of the above work,
a possible mechanism leading to 9 and 10 is described in Scheme 4:
first, the reaction of Fe3(CO)12 and [HNEt3][G0NHCS2] yields an an-
(OC)3Fe
E-S
Fe(CO)3
l l-Ph2
-G0NHCS2ꢀ) analogous to Fe2(CO)6(
1. Et3N/Fe3(CO)12
2. E-X
ion of type Fe2(CO)6(
PCS2ꢀ); then, it undergoes a fragmentation to give an intermediate
of type [(
-G0NHCS)Fe2(CO)5( -Sꢀ)] (M0), with cleavage of a C–S
bond and loss of CO; finally, M0 is trapped by PhCOCl to form a
product [Fe2(CO)5( -SCOPh)]. Although com-
-G0N(COPh)CS)(
plexes of type ( -R2NC@S) have been synthesized
-R0S)Fe2(CO)6(
by Seyferth and coworkers via reactions of [(
-R0S)Fe2(CO)6
-CO)]ꢀ generated in situ from the mixture of Fe3(CO)12/HSR0/
PhCOCH2CS2H
S
C
l
l
CH2COPh
(2-4)
l
l
l
l
l
(
l
(OC)3Fe
S
Fe(CO)3
S
Et3N with N,N-dialkylthiocarbmoyl chlorides R2NC(@S)Cl (R0 = tBu;
R = Me, Et), unfortunately, they have not been characterized by
X-ray crystallography [12]. From the green chemistry point of
view, inexpensive and readily available starting materials (amines
G0NH2, acyl chlorides and CS2) will make this new method without
the unpleasant odor of thiols more fascinating.
Fe3(CO)12 or Fe2(CO)9
THF
C
CHCOPh
(5)
Scheme 2. Syntheses of complexes 2–5 (E = CH3, 2; E = PhCH2, 3; E = CH2@CHCH2,
4).
3.2. X-ray structures of complexes
The structures of all complexes have been determined by X-ray
diffraction analyses. The selected geometric parameters have been
listed in Table 3 for 1–5 and Table 4 for 6–10. As shown in Fig. 1, 1
contains the Ph2P(@S)C(S)SMe ligand functioning as a six-electron
donor, which doubly bridges the Fe2(CO)6 core, viz. in a k2C,S:k2S
manner. Each Fe atom conforms to the 18-electron rule and has a
distorted octahedral geometry with three of six coordination sites
occupied by carbonyl groups. Therefore, two Fe(CO)3 units are
inequivalent. The Fe–Fe distance is 2.6266(4) Å, indicating the
presence of a single bond [18,41]. The S1 atom asymmetrically
binds the two Fe(CO)3 units with Fe1–S1 and Fe2–S1 distances of
2.2024(6) and 2.2910(6) Å. The S2 atom of the SMe unit links the
Fe2 atom with the Fe2–S2 bond length of 2.2894(6) Å. The Fe1–
C7 bond of 2.0306(18) Å proves the existence of a single bond
[18,39–41]. Consistent with this, the S1–C7 bond of 1.7857(18) Å
is of single bond and slightly shorter than the S2–C7 bond
(1.796(2) Å). However, the related values of 4-tBuC6H4C(@S)SMe
are 1.630 (C@S), 1.724 (C–SMe) and 1.788 (S–Me) Å [42]. Thus,
the C7 atom in 1 is sp3-hybridized, this fact is in agreement with
the below-described 13C NMR spectroscopy. In addition, the P1–
S3 distance of 1.9523(8) Å is in accordance with the presence of
a double bond [19,43]. As displayed in Fig. 2, the bonding mode
of the functional group CS2 in 2 is also a k2C,S:k2S fashion. The
Fe–Fe single bond length is 2.6265(6) Å and very close to that of
1. The S1 atom asymmetrically binds the two Fe(CO)3 units with
Fe1–S1 and Fe2–S1 distances of 2.2022(7) and 2.2787(8) Å. Unlike
1, the Fe2–S2 bond of 2.2914(7) Å is longer than the Fe2–S1 bond.
The C7 atom links four atoms with Fe1–C7, S1–C7, S2–C7 and C7–
C8 distances of 2.006(2), 1.785(2), 1.785(2) and 1.515(3) Å. The
(OC)3Fe
Me-S
Fe(CO)3
S
1. Et3N/Fe3(CO)12
2. Me-I
GCS2H
C
G
(6-7)
Scheme 3. Syntheses of complexes 6–7 (G = 4-MeOC6H4COCH2, 6; G =
C5H5FeC5H4COCH2, 7).
(OC)3Fe
Me-S
Fe(CO)3
1. Et3N/Fe3(CO)12
2. MeI
Fe(C5H4COCH2CS2H)2
S
C
CH2COC5H4 2Fe
(8)
Eq. 2. Synthesis of complex 8.
reported [18]. Since the 2-pyridyl group may act as a donor group
like Ph2P, the reaction of Fe3(CO)12 with [HNEt3][2-C5H4NNHCS2] is
carried out in order to obtain new findings. After the mixture is
quenched by PhCOCl, a dark-brown complex 9 is isolated. An X-
ray diffraction study on 9 proves the presence of anions of type
[Fe2(CO)5(l-GCS)(l
-Sꢀ)] (M0, G = 2-C5H4NNH, G0 = 2-C5H4N)

Y.-C. Shi et al. / Polyhedron 56 (2013) 160–171
165
Table 3
Selected geometric parameters (Å, °) for 1–5
1
2
3
4
5
Fe1–Fe2
Fe1–S1
Fe2–S1
Fe2–S2
Fe1–C7
2.6266(4)
2.2024(6)
2.2910(6)
2.2894(6)
2.0306(18)
1.7857(18)
1.796(2)
Fe1–Fe2
Fe1–S1
Fe2–S1
Fe2–S2
Fe1–C7
2.6265(6)
2.2022(7)
2.2787(8)
2.2914(7)
2.006(2)
1.785(2)
1.785(2)
1.807(3)
1.515(3)
71.75(2)
59.31(7)
82.87(7)
Fe1–Fe2
Fe1–S1
Fe2–S1
Fe2–S2
Fe1–C7
2.6225(7)
2.1954(9)
2.2817(9)
2.2865(8)
2.014(3)
1.783(3)
1.784(3)
1.826(3)
1.514(4)
71.68(3)
59.77(9)
83.43(9)
Fe1–Fe2
Fe1–S1
Fe2–S1
Fe2–S2
Fe1–C7
2.6124(6)
2.1728(8)
2.2612(7)
2.2752(8)
1.996(3)
1.775(3)
1.786(2)
1.823(3)
1.506(3)
72.16(2)
59.75(8)
82.87(8)
Fe1–Fe2
Fe1–S1
Fe1–S2
Fe2–S1
Fe2–S2
2.4760(5)
2.2907(7)
2.2840(7)
2.2894(8)
2.2868(7)
2.7197(10)
1.777(2)
1.776(2)
1.336(3)
65.45(2)
65.60(2)
99.90(12)
S1–C7
S2–C7
S1–C7
S2–C7
S1–C7
S2–C7
S1–C7
S2–C7
S1ꢁꢁꢁS2
S1–C7
C20–S2
S3–P1
Fe1–S1–Fe2
Fe1–S1–C7
Fe2–S2–C7
1.811(2)
S2–C16
C7–C8
Fe1–S1–Fe2
Fe1–S1–C7
Fe2–S2–C7
S2–C16
C7–C8
Fe1–S1–Fe2
Fe1–S1–C7
Fe2–S2–C7
S2–C16
C7–C8
Fe1–S1–Fe2
Fe1–S1–C7
Fe2–S2–C7
S2–C7
C7–C8
Fe1–S1–Fe2
Fe1–S2–Fe2
S1–C7–S2
1.9523(8)
71.512(18)
60.14(6)
83.05(6)
Table 4
Selected geometric parameters (Å, °) for 6–10
6
7
8
9
10
Fe1–Fe2
Fe1–S1
Fe2–S1
Fe2–S2
Fe1–C7
S1–C7
S2–C7
S2–C17
C7–C8
2.6331(6)
2.1943(9)
2.2826(8)
2.2767(8)
2.004(3)
1.786(3)
1.788(3)
1.810(3)
1.517(4)
Fe1–Fe2
Fe1–S1
Fe2–S1
Fe2–S2
Fe1–C7
S1–C7
S2–C7
S2–C8
C7–C9
Fe4–Fe5
Fe4–S3
Fe5–S3
Fe5–S4
Fe4–C27
S3–C27
2.6402(7)
2.1980(9)
2.2678(8)
2.2922(8)
2.013(3)
1.783(3)
1.793(3)
1.811(3)
1.510(4)
2.6338(6)
2.1965(8)
2.2822(8)
2.2774(8)
2.016(3)
1.780(3)
1.787(3)
1.808(3)
1.517(4)
72.47(3)
59.68(9)
82.99(9)
72.01(3)
59.84(9)
82.96(9)
Fe1–Fe2
Fe1–S1
Fe2–S1
Fe2–S2
Fe1–C7
S1–C7
S2–C7
S2–C8
C7–C9
Fe3–Fe4
Fe3–S3
Fe4–S3
Fe4–S4
Fe3–C23
S3–C23
2.6171(16)
2.196(2)
2.267(2)
2.298(2)
2.010(7)
1.770(6)
1.791(7)
1.800(9)
1.526(9)
2.6331(15)
2.201(2)
2.274(2)
2.306(2)
2.020(7)
1.784(6)
1.786(7)
1.822(8)
1.503(10)
71.78(7)
57.97(10)
82.4(2)
Fe1–Fe2
Fe1–S2
Fe2–S1
Fe2–S2
Fe1–N2
Fe1–C1
Fe1–C2
Fe1–C6
Fe2–C4
Fe2–C6
S1–C6
S2–C19
N1–C6
2.5874(7)
2.2614(11)
2.3362(9)
2.2725(10)
1.972(3)
1.828(4)
1.746(4)
1.924(3)
1.806(4)
2.164(3)
1.709(3)
1.833(4)
1.419(4)
1.385(4)
1.459(4)
1.483(4)
1.479(5)
1.199(3)
69.60(3)
167.44(15)
62.41(10)
73.14(12)
150.92(14)
78.31(11)
Fe1–Fe2
Fe1–S2
Fe2–S1
Fe2–S2
Fe1–N2
Fe1–C1
Fe1–C2
Fe1–C6
Fe2–C4
Fe2–C6
S1–C6
S2––C17
N1–C6
N1–C7
N1–C10
C10–C11
C17–C18
C10–O6
Fe1–S2–Fe2
C1–Fe1–C6
C6–S1–Fe2
S1–C6–Fe2
C4–Fe2–C6
Fe1–C6–Fe2
2.5967(4)
2.2473(6)
2.3255(6)
2.2671(6)
1.9585(16)
1.832(3)
1.757(2)
1.925(2)
1.806(2)
2.1826(17)
1.7084(18)
1.831(2)
1.439(2)
1.381(2)
1.424(2)
1.481(3)
1.479(3)
1.208(2)
N1–C7
N1–C12
C12–C13
C19–C20
C12–O6
Fe1–S2–Fe2
C1–Fe1–C6
C6–S1–Fe2
S1–C6–Fe2
C4–Fe2–C6
Fe1–C6–Fe2
S4–C27
S4–C28
S4–C23
S4–C24,
C22–C23
Fe1–S1–Fe2
Fe1–S1–C7
Fe2–S2–C7
Fe3–S3–Fe4,
Fe3–S3–C23
Fe4–S4–C23
C27–C29
Fe1–S1–Fe2
Fe1–S1–C7
Fe2–S2–C7
Fe4–S3–Fe5
Fe4–S3–C27
Fe5–S4–C27
70.226(17)
166.89(10)
63.36(6)
72.24(6)
149.06(9)
78.15(6)
Fe1–S1–Fe2
Fe1–S1–C7
Fe2–S2–C7
72.02(3)
59.43(9)
82.97(9)
72.07(7)
59.8(2)
82.7(2)
S2–C16 bond of 1.807(3) Å is slightly longer than the S2–C7 bond.
It is worth noting that the corresponding values in the related com-
pound Fe2(CO)6(2-C4H3SCS2Me) are 2.618(1) (Fe1–Fe2), 2.188(1)
(Fe1–S1), 2.270(1) (Fe2–S1), 2.282(1) (Fe2–S2), 2.007(3) (Fe1–
C7), 1.772(3) (S1–C7), 1.781(3) (S2–C7) and 1.803(4) (S2–Me) Å
[39]. For 3 (Fig. 3), the Fe–Fe single bond length is 2.6225(7) Å.
The bond lengths about the S1 atom are 2.1954(9) (Fe1–S1) and
2.2817(9) (Fe2–S1) Å. Furthermore, the bond lengths about the
C7 atom are 2.014(3) (Fe1–C7), 1.783(3) (S1–C7), 1.784(3) (S2–
C7) and 1.514(4) (C7–C8) Å while those of the S2 atom are
2.2865(8) (Fe2–S2) and 1.826(3) (S2–C16) Å. Fig. 4 indicates that
the functional group CS2 in 4 links the Fe2(CO)6 core in the same
pattern as those in 1–3. The corresponding geometric parameters
are easily compared with those of 1–3. Unlike 1–4, each Fe atom
in 5 (Fig. 5) is linked by three carbonyls, two S atoms and one other
iron atom and possesses a distorted octahedral geometry. The Fe–
Fe distance of 2.4760(5) Å is slightly shorter than that found in an
[16,17]. The S1ꢁ ꢁ ꢁS2 separation of 2.7197(10) Å suggests some de-
gree of S–S interaction (non-bonding minimum separation 3.7 Å).
As in 2–4, the functional group CS2 of 6 (Fig. 6) shows the same
bonding mode. The measured distance of an Fe–Fe single bond is
2.6331(6) Å. The others are 2.1943(9), 2.2826(8), 2.004(3),
1.786(3), 1.788(3), 1.517(4), 2.2767(8) and 1.810(3) Å. Interest-
ingly, as shown in Fig. 7, the asymmetric unit of 7 contains two
independent molecules labeled as 7a and 7b. For 7a, the S1 atom
asymmetrically bridges the two Fe(CO)3 units with Fe1–S1 and
Fe2–S1 distances of 2.1980(9) and 2.2678(8) Å. The Fe–Fe single
bond length is 2.6402(7) Å. Four Fe1–C7, S1–C7, S2–C7 and C7–
C9 bond lengths about C7 atom are 2.013(3), 1.783(3), 1.793(3)
and 1.510(4) Å, respectively. The MeS group is coordinated to Fe2
atom with the Fe2–S2 bond length of 2.2922(8) Å. In addition,
the S2–Me bond length is 1.811(3) Å. For 7b, the corresponding
values are 2.6338(6), 2.1965(8), 2.2822(8), 2.2774(8), 2.016(3),
1.780(3), 1.787(3), 1.517(4) and 1.808(3) Å. Consequently, they
possess almost same bond lengths. Two O7@C10 and C11–C12
bonds form a torsion angle of ꢀ16.23(4)° whereas O14@C30 and
C31–C32 make an angle of 171.54(4)°. Such a big difference sug-
gests that they belong to conformers [44–48]. Fig. 8 displays that
8 has two Fe2(CO)6(COCH2CS2Me) units. The Fe1–Fe2 bond of
2.6171(16) Å is shorter than the Fe3–Fe4 bond (2.6331(15) Å)
whereas the latter is very close to those of 1–4 and 6–7. As in
analogous
compound
(l-4-FC6H4COCH@CS2)Fe2(CO)6
(2.4872(3) Å) [16]. The two sulfur atoms almost symmetrically
bridge the Fe–Fe bond. The C7–C8 distance of 1.336(3) Å is in
accordance with a carbon–carbon double bond which is generally
at 1.34 Å. This bond length is also close to that found in the related
complex (1.328(2) Å). The Fe–S distances as well as the Fe–S–Fe
angles are in the range observed in related Fe2S2 complexes

166
Y.-C. Shi et al. / Polyhedron 56 (2013) 160–171
Fig. 1. Ortep plot of 1. Displacement ellipsoids are drawn at the 30% probability level.
Fig. 2. Ortep plot of 2. Displacement ellipsoids are drawn at the 30% probability level.
1–4 and 6–7, the S1 atom links one Fe2(CO)6 unit asymmetrically.
Similarly, the S3 atom binds the other. The torsion angle between
the O7@C10 and C11–C12 bonds is 173.0(8)° while the O8@C21
bond with the C16–C20 bond forms a torsion angle of 170.1(7)°.
This suggests that the ketonic O8C21 group does not involve the
conjugation of the substituted Cp group. This conclusion is further
supported by the C10–C11 and C20–C21 bonds of 1.449(10) and
1.502(10) Å, the latter is typical of a single bond [44–48]. As shown
in Fig. 9, 9 is an Fe2(CO)5 complex with two terminal carbonyl li-
gands on Fe1 and three on Fe2, it contains the bridging, three-elec-
tron SCOPh and five-electron G0N(COPh)CS ligands. The angle of
C6ꢁ ꢁ ꢁS2–C19 = 143.11(14)° reveals that the benzoyl group attached
to the S2 atom is at an equatorial position, namely, 9 is an e-type
isomer resulting from one of two axial (a) and equatorial (e) orien-
tations of the organic group on sulfur with respect to the Fe2S
plane [11–13,49]. The Fe1–Fe2 bond distance (2.5874(7) Å) is sig-
nificantly shorter than those in 1–8. The Fe1–N2 bond distance is
1.972(3) Å. Interestingly, the bond distances (Fe1–C6 = 1.924(3) Å,
Fe2–C6 = 2.164(3) Å, Fe2–S1 = 2.3362(9) Å, S1–C6 = 1.709(3) Å)
indicate that the C6S1 thioacyl group as a three-electron donor is
attached to Fe1 and Fe2 atoms in a
the bondings in the reported complexes such as (
4-S)Fe2(CO)6( -PhNHC@S) (C@S, 1.698(5) Å) and (
Se)Fe2(CO)6( -PhCH2NHC@S) (C@S, 1.691(4) Å) are r, r
r
,
p
-bonded manner. However,
-MeS)Fe2(CO)6-
-p-MeC6H4-
-modes
l
(l
l
l
l
in nature [49,50]. The Fe1–C6 bond distance is markedly shorter
than those of Fe–C single bonds in 1–4 and 6–8, displaying that

Y.-C. Shi et al. / Polyhedron 56 (2013) 160–171
167
Fig. 3. Ortep plot of 3. Displacement ellipsoids are drawn at the 30% probability level.
Fig. 4. Ortep plot of 4. Displacement ellipsoids are drawn at the 30% probability level.
the Fe1–C6 bond is of some double-bond character [50]. Further-
more, the Fe1–C1 bond of 1.828(4) Å is significantly longer than
the other Fe–CO bonds, suggesting that the C6 atom of the thioacyl
ligand with some carbene character has a large tran influence. In
agreement with this, the bond angle of C1–Fe1–C6 exhibits a value
of 167.44(15)°, which is close to 180°. The S2 atom spans the two
Fe atoms slightly asymmetrically, with 2.2614(11) and
2.2725(10) Å bond lengths of Fe1–S2 and Fe2–S2. Notably, the
five-membered chelating ring Fe1C6N1C7N2 is planar and makes
two dihedral angles of 61.05(15) and 64.67(17)° with three-mem-
bered rings Fe2C6S1 and Fe1Fe2C6. The short distance of S1ꢁ ꢁ ꢁS2
(2.9887(12) Å) shows the existence of an intramolecular contact
in 9. Fig. 10 displays that 10 is an Fe2(CO)5 complex consisting of
the bridging, three-electron SCOPh and five-electron G0N(COPh)CS
ligands. The C6ꢁ ꢁ ꢁS2–C17 angle of 146.28(8)° reveals that the ben-
zoyl group bound to the S2 atom is at an equatorial position, viz. 10
is an e-type isomer. The Fe1–Fe2 bond distance of 2.5967(4) Å is
very close to that of 9. The Fe1–N2 bond distance of 1.9585(16) Å
is slightly shorter than that in 9. As in 9, the thioacyl group links
Fe1 and Fe2 atoms in a
r, p-bonding mode (Fe1–C6 = 1.925(2) Å,
S1–C6 = 1.7084(18) Å, Fe2–S1 = 2.3255(6) Å, Fe2–C6 = 2.1826(17)
Å). The S2 atom bridges the two metals asymmetrically (Fe1–
S2 = 2.2473(6) Å, Fe2–S2 = 2.2671(6) Å). As also noted in 9, the
Fe1–C1 bond distance of 1.832(3) Å and the C1–Fe1–C6 bond angle
of 166.89(10)° indicate that the C6 atom of the thioacyl ligand with
some carbene character has a significant tran influence. Similarly,
the five-atom Fe1C6N1C7N2 ring in 10 is planar and forms two
dihedral angles of 61.59(8)° and 65.78(8)° with three-membered
rings Fe2C6S1 and Fe1Fe2C6, there is an intramolecular contact be-
tween two S atoms (the distance of S1ꢁ ꢁ ꢁS2 is 2.9623(8) Å) in 10.

168
Y.-C. Shi et al. / Polyhedron 56 (2013) 160–171
Fig. 5. Ortep plot of 5. Displacement ellipsoids are drawn at the 30% probability level.
Fig. 6. Ortep plot of 6. Displacement ellipsoids are drawn at the 20% probability level.
Fig. 7. Ortep plot of 7. Displacement ellipsoids are drawn at the 20% probability level.

Y.-C. Shi et al. / Polyhedron 56 (2013) 160–171
169
Fig. 8. Ortep plot of 8. Displacement ellipsoids are drawn at the 20% probability level.
Fig. 9. Ortep plot of 9. Displacement ellipsoids are drawn at the 30% probability level.
3.3. Spectroscopies of complexes
displays one AB quartet at 7.90 and 7.96 ppm. However, the COCH2
group in 4 shows two doublets at 3.80–3.83 (1H, 2JH–H = 18 Hz) and
5.25–5.28 ppm (1H, 2JH–H = 18 Hz). In addition, the 1H NMR spectra
of all complexes exhibit the corresponding signals for their aryl
and other groups. In the 13C{1H} NMR spectra, each of 1–8 exhibits
the only singlet in the range of 207–213 ppm corresponding to ter-
minal carbonyl C atoms, suggesting that the carbonyl ligands are
undergoing rapid exchange between two Fe(CO)3 groups on the
NMR time scale at room temperature [18,19]. 9 shows three sing-
lets at 206.9, 212.8 and 213.6 ppm for terminal carbonyl C atoms
while 10 displays five singlets at 205.9, 206.3, 212.4, 212.9 and
213.7 ppm. The ketonic C@O group exhibits a singlet at 195.1 for
2, 194.2 for 3, 194.8 for 4, 188.1 for 5, 194.2 for 6, 199.0 for 7
and 198.9 ppm for 8. Two COPh groups as two singlets occur at
158.4 and 171.5 ppm for 9 and 164.9 and 169.3 ppm for 10. It is
worth noting that in the 13C{1H} NMR spectra the C@S group ap-
pears as a singlet at 198.7 ppm for 9 and at 198.5 ppm for 10. Com-
pared with dithioester RCS2R0 (230 ppm) and xanthate ROCS2R0
All novel complexes described above have also been character-
ized by elemental analyses and spectroscopies. The IR spectra show
characteristic absorption bands in the region 1907–2082 cmꢀ1 for
their terminal CO ligands. Additionally, the signal of the ketonic
C@O group appears at 1673 cmꢀ1 for 2, 1687 cmꢀ1 for 3,
1689 cmꢀ1 for 4, 1651 cmꢀ1 for
5
and 1670 cmꢀ1 for 6,
1665 cmꢀ1 for 7, 1659 cmꢀ1 for 8 while those of two C@O groups
do at 1708 and 1665 cmꢀ1 for 9 and 1684 and 1663 cmꢀ1 for 10.
The 1H NMR spectrum of 2 exhibits for two magnetically nonequiv-
alent protons of the COCH2 group one AB quartet at 3.15 and
3.60 ppm and one singlet at 2.26 ppm assignable to the CH3 group.
For 3, the CH2 group of the benzyl group as one AB quartet appears
at 2.79 and 3.67 ppm while the CH2 group of the COCH2 group at
3.71 and 4.01 ppm. Like 2, each of 6–8 shows for two magnetically
nonequivalent protons of the COCH2 group one AB quartet. Fur-
thermore, in the 1H NMR spectrum of 10, the 2-thiazyl group also

170
Y.-C. Shi et al. / Polyhedron 56 (2013) 160–171
Fig. 10. Ortep plot of 10. Displacement ellipsoids are drawn at the 30% probability level.
(213 ppm), each CS2 unit of 1–8 shows a high-field resonance, this
References
is in agreement with the above X-ray diffraction analyses [37,40].
[1] J.F. Capon, F. Gloaguen, F.Y. Pétillon, P. Schollhammer, J. Talarmin, Coord.
Chem. Rev. 253 (2009) 1476.
[2] C. Tard, C.J. Pickett, Chem. Rev. 109 (2009) 2245.
4. Conclusions
[3] F. Gloaguen, T.B. Rauchfuss, Chem. Soc. Rev. 38 (2009) 100.
[4] X. Zhao, Y.-M. Hsiao, C.-H. Lai, J.H. Reibenspies, M.Y. Darensbourg, Inorg. Chem.
41 (2002) 699.
Two new routes to Fe/S cluster complexes have been exploited.
Reactions of cluster salts of anions [Fe2(CO)6(l
-GCS2)]ꢀ (G = Ph2PS,
[5] W. Hieber, P. Spacu, Z. Anorg, Allg. Chem. 233 (1937) 353.
[6] J.A. DeBeer, R.J. Haines, J. Chem. Soc. D (1970) 288.
[7] J.A. DeBeer, R.J. Haines, J. Organomet. Chem. 24 (1970) 757.
[8] A. Winter, L. Zsolnai, G. Huttner, Chem. Ber. 115 (1982) 1286.
[9] A. Winter, L. Zsolnai, G. Huttner, J. Organomet. Chem. 250 (1983) 409.
[10] J. Takács, L. Markó, J. Organomet. Chem. 247 (1983) 223.
[11] D. Seyferth, G.B. Womack, J.C. Dewan, Organometallics 4 (1985) 398.
[12] D. Seyferth, G.B. Womack, C.M. Archer, J.C. Dewan, Organometallics 8 (1989)
430.
[13] D. Seyferth, G.B. Womack, C.M. Archer, J.P. Fackler Jr., D.O. Marler,
Organometallics 8 (1989) 443.
[14] L.-C. Song, Acc. Chem. Res. 38 (2005) 21.
[15] L.-C. Song, Sci. China Ser. B: Chem. 52 (2009) 1.
[16] C. Alvarez-Toledano, E. Delgado, B. Donnadieu, E. Hernández, G. Martín, F.
Zamora, Inorg. Chim. Acta 351 (2003) 119.
[17] C. Alvarez-Toledano, J. Enríquez, R.A. Toscano, M. Martínez-García, E. Cortés-
Cortés, Y.M. Osornio, O. García-Mellado, R. Gutiérrez-Pérez, J. Organomet.
Chem. 577 (1999) 38.
[18] Y.-C. Shi, H.-R. Cheng, H. Tan, J. Organomet. Chem. 716 (2012) 39.
[19] Y.-C. Shi, F. Gu, Chem. Commun. 49 (2013) 2255.
[20] R.B. King, Organometallic Syntheses: Transition-Metal Compounds, Academic
Press, New York, 1965. 95.
ArCOCH2) generated from Fe3(CO)12 and salts of heteroallyl anions
[NEt4][Ph2P(@S)CS2] and [HNEt3][GCS2] formed from NEt3 and
dithiocarboxylic acid GCS2H (G = PhCOCH2, 4-MeOC6H4COCH2,
C5H5FeC5H4COCH2) with a series of electrophiles have led to the
syntheses of new Fe/S cluster complexes 1–4 and 6–7. This meth-
odology can be also extended to tetrathiodicarboxylic acids, for
example, the reaction of Fe3(CO)12, Fe(C5H4COCH2CS2H)2 and
NEt3 with MeI gives 8. Interestingly, reactions of Fe3(CO)12 with
dithiocarbamate salts [HNEt3][GCS2] (G = 2-C5H4NNH, 2-C3H2-
NSNH) yield cluster salts of type [HNEt3][Fe2(CO)5(
l-GC@S)
(l-S)]. Trapping the S-centered cluster anions with PhCOCl affords
9 and 10. All the complexes have been structurally determined by
X-ray crystallography. Without doubt, the new chemistry of cluster
anions of type
group; Y = S, Se; Z = S, Se, NR,CHR) will be further developed.
[l
-(G-C(@Y)-Z)Fe2(CO)6]ꢀ (G = potential donor
[21] O. Dahl, O. Larsen, Acta Chem. Scand. 23 (1969) 3613.
[22] C.-Y. Liu, J.-J. Lih, Fresenius Z Anal. Chem. 332 (1988) 171.
[23] W. Weigand, G. Bosl, K. Polborn, Chem. Ber. 123 (1990) 1339.
[24] J. Buchweitz, R. Gompper, K. Polborn, C. Robl, M.-T. Sailer, W. Weigand, Chem.
Ber. 127 (1994) 23.
Acknowledgments
We are grateful to the Mao Zedong Foundation of China, Project
funded by the Priority Academic Program Development of Jiangsu
Higher Education Institutions (PAPD), Natural Science Foundation
of China (No. 20572091) and Natural Science Foundation of Jiangsu
Province (No. 05KJB150151) for financial support of this work.
[25] G. L’abbé, Synthesis (1987) 525.
[26] E.B. Knott, J. Chem. Soc. (1956) 1644.
[27] A.E.S. Fairfull, D.A. Peak, J. Chem. Soc. (1955) 796.
[28] Bruker, SAINT-Plus, Bruker AXS Inc., Madison, Wisconsin, USA, 2003.
[29] G.M. Sheldrick, SADABS, University of Göttingen, Germany, 2004.
[30] M.C. Burla, R. Caliandro, M. Camalli, B. Carrozzini, G.L. Cascarano, L. DeCaro, C.
Giacovazzo, G. Polidori, R. Spagna, J. Appl. Crystallogr. 38 (2005) 381.
[31] G.M. Sheldrick, Acta Crystallogr. A64 (2008) 112.
[32] L.J. Farrugia, J. Appl. Crystallogr. 32 (1999) 837.
Appendix A. Supplementary data
[33] L.-C. Song, J. Cheng, J. Yan, C.-R. Liu, Q.-M. Hu, Organometallics 29 (2010) 205.
[34] L.-C. Song, C.-H. Qi, H.-L. Bao, X.-N. Fang, H.-B. Song, Organometallics 31 (2012)
5358.
[35] G. Hogarth, Dinuclear iron compounds, in: R.H. Crabtree, D.M.P. Mingos (Eds.),
Comprehensive Organometallic Chemistry III, Elsevier, 2007, pp. 221–243.
[36] D. Seyferth, G.B. Womack, L.-C. Song, M. Cowie, B.W. Hames, Organometallics 2
(1983) 928.
[37] D. Seyferth, G.B. Womack, M.K. Gallagher, M. Cowie, B.W. Hames, J.P. Fackler
Jr., A.M. Mazany, Organometallics 6 (1987) 283.
[38] B. Dadamoussa, A. Darchen, P. L’Haridon, C. Larpent, H. Patin, J.-Y. Thepot,
Organometallics 8 (1989) 564.
CCDC 893108–893115 and 908931–908932 contain the supple-
mentary crystallographic data for 1–3, 6–10 and 4–5. These data
can be obtained free of charge via http://www.ccdc.cam.ac.uk/con-
ts/retrieving.html, or from the Cambridge Crystallographic Data
Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223-
336-033; or e-mail: deposit@ccdc.cam.ac.uk. Supplementary data
associated with this article can be found, in the online version, at
http://dx.doi.org/10.1016/j.poly.2013.03.049.

Y.-C. Shi et al. / Polyhedron 56 (2013) 160–171
171
[39] A. Benoit, J.-Y.L.M. Rouille, C. Mahe, H. Patin, J. Organomet. Chem. 218 (1981)
C67.
[40] A. Lagadec, B. Misterkiewicz, H. Patin, A. Mousser, J.-Y.L. Marouille, J.
Organomet. Chem. 315 (1986) 201.
[41] R.S. Paley, Iron: organometallic chemistry, in: Encyclopedia of Inorganic
Chemistry, Wiley, 2006, pp. 1–84.
[42] W.A. Schenk, D. Rüb, C. Burschka, J. Organomet. Chem. 328 (1987) 287.
[43] D. Seyferth, K.S. Brewer, T.G. Wood, M. Cowie, R.W. Hilts, Organometallics 11
(1992) 2570.
[45] Y.-C. Shi, H.-M. Yang, H.-B. Song, Y.-H. Liu, Polyhedron 23 (2004) 1541.
[46] Y.-C. Shi, S.-H. Zhang, H.-J. Cheng, W.-P. Sun, Acta Crystallogr. C62 (2006)
m407.
[47] Y.-C. Shi, H.-J. Cheng, S.-H. Zhang, Polyhedron 27 (2008) 3331.
[48] Y.-C. Shi, Y.-Y. Hu, J. Coord. Chem. 62 (2009) 1302.
[49] L.-C. Song, Q.-M. Hu, H.-T. Fan, B.W. Sun, M.-Y. Tang, Y. Chen, Y. Sun, C.-X. Sun,
Q.-J. Wu, Organometallics 19 (2000) 3909.
[50] L.-C. Song, G.-L. Lu, Q.-M. Hu, H.-T. Fan, J.-B. Chen, J. Sun, X.-Y. Huang, J.
Organomet. Chem. 627 (2001) 255.
[44] Y.-C. Shi, H.-M. Yang, W.-B. Shen, C.-G. Yan, X.-Y. Hu, Polyhedron 23 (2004) 15.