Synthesis and structures of CpFe(CO)2(κE-ECS2Ph) and [CpFe(CO)(κ2S,E-ECS2Ph)] (E = S, Se)

Article abstract of DOI:10.1016/j.poly.2007.04.010

The iron trithiocarbonato complex CpFe(CO)₂(κS-SCS₂Ph) (1a) and its selenodithiocarbonato analogue CpFe(CO)₂(κSe-SeCS₂Ph) (1b) were generated by room temperature reactions of (μ-E_x)[CpFe(CO)₂]₂ (E = S; x = 2, 3. E = Se; x = 1) with PhSC(S)Cl. These compounds can be converted into the complexes CpFe(CO)(κ²S,E-ECS₂Ph) [E = S (2a), Se (2b)], in which the trithiocarbonato or the selenodithiocarbonato ligand is bonded to the iron in a chelate form, under photolytic conditions. The composition and structure of all products have been verified by elemental analyses, IR and ¹H NMR spectroscopies. The crystal structures for compounds 1a, 1b, and 2b show a three-legged piano-stool configuration at Fe in each complex. The spectroscopic and structural data in this work are commensurate with the electronic factor of the S- and Se-donor ligands.

Full text of DOI:10.1016/j.poly.2007.04.010

Polyhedron 26 (2007) 3920–3924
www.elsevier.com/locate/poly
Synthesis and structures of CpFe(CO)2(jE-ECS2Ph)
and [CpFe(CO)(j2S,E-ECS2Ph)] (E = S, Se)
a,
b
Mohammad El-khateeb *, Alexander Roller
a
Chemistry Department, Jordan University of Science and Technology, Irbid 22110, Jordan
b
Institute of Inorganic Chemistry, University of Vienna, Vienna, Austria
Received 11 January 2007; accepted 17 April 2007
Available online 27 April 2007
Abstract
The iron trithiocarbonato complex CpFe(CO)2(jS-SCS2Ph) (1a) and its selenodithiocarbonato analogue CpFe(CO)2(jSe-SeCS2Ph)
(1b) were generated by room temperature reactions of (l-Ex)[CpFe(CO)2]2 (E = S; x = 2, 3. E = Se; x = 1) with PhSC(S)Cl. These com-
pounds can be converted into the complexes CpFe(CO)(j2S,E-ECS2Ph) [E = S (2a), Se (2b)], in which the trithiocarbonato or the sel-
enodithiocarbonato ligand is bonded to the iron in a chelate form, under photolytic conditions. The composition and structure of all
products have been verified by elemental analyses, IR and 1H NMR spectroscopies. The crystal structures for compounds 1a, 1b,
and 2b show a three-legged piano-stool configuration at Fe in each complex. The spectroscopic and structural data in this work are com-
mensurate with the electronic factor of the S- and Se-donor ligands.
ꢀ 2007 Elsevier Ltd. All rights reserved.
Keywords: Iron chalcogenides; Cyclopentadienyl piano-stool complexes; X-ray diffraction; Trithiocarbonates; Selenodithiocarbonates; Metal carbonyls
1. Introduction
fonyl chlorides bearing strong electron-withdrawing groups
such as Cl3CSO2Cl, F3CSO2Cl and C6F5SO2Cl [6], while
the selenide (l-Se)[CpFe(CO)2]2 can react with simple alkyl
and aryl sulfonyl chlorides [7].
The reactions of the iron chalcogenides (l-Ex)-
[CpFe(CO)2]2 (E = S; x = 2, 3. E = Se; x = 1) with electro-
philes have been the subject of multiple investigations by us
and others [1–10]. The reactions of these chalcogenides
with acid chlorides were reported to give chalcogeno-carb-
oxylato complexes with the general formula CpFe(CO)2-
ECOR (E = S, Se) [1–4]. Starting from oxalyl chloride,
the chalcogeno-oxalato dimers [CpFe(CO)2ECO]2 have
been prepared. On the other hand, the reaction of O-alkyl
oxalyl chlorides with these chalcogenides gave the expected
O-alkyl chalcogeno-oxalato complexes CpFe(CO)2ECO-
CO2R [5]. The chalcogenosulfonato complexes CpFe-
(CO)2ESO2R [6,7] were obtained from the corresponding
chalcogenides and sulfonyl chlorides. It was found that
the sulfides (l-Sx)[CpFe(CO)2]2 react exclusively with sul-
Recent work in our laboratory has shown that the reac-
tions of these chalcogenides with chloroformates, ROCOCl,
produce the iron mono-chalcogenocarbonato complexes
CpFe(CO)2ECO2R [8,9]. The dithiocarbonato complexes
CpFe(CO)2(jS-SC(S)OR) and the selenothiocarbonato
complexes CpFe(CO)2(jSe-SeC(S)OR) were obtained from
the reactions of the chalcogenides with alkyl or aryl chloro-
thioformates ROC(S)Cl [10,11]. Photolysis of THF solu-
tions of the latter dithiocarbonato or selenothiocarbonato
complexes lead to the dissociation of one carbonyl group
and the generation of the chelate complexes CpFe-
(CO)(j2E,S-EC(S)OR) [10,11]. Reactions of the iron dimers
[Cp0Fe(CO)2]2 (Cp0 = C5H5, C5Me5) with [EtOC(S)S]2 in
cyclohexane were reported to produce the ethyl-dithiocar-
bonato complexes Cp0Fe(CO)2(jS-S2COEt) [12,13].
Photolysis of these complexes gave Cp0Fe(CO)(j2S,S-S2-
COEt), which exhibit bidentate coordination of the ethyl-
*
Corresponding author. Tel.: +962 2 7201000; fax: +962 2 7207110.
E-mail address: kateeb@just.edu.jo (M. El-khateeb).
0277-5387/$ - see front matter ꢀ 2007 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2007.04.010

M. El-khateeb, A. Roller / Polyhedron 26 (2007) 3920–3924
3921
dithiocarbonato ligand [14]. Treatment of the latter com-
plexes with phosphine or phosphite ligands gave the mixed
carbonyl-phosphine or phosphite complexes Cp0Fe(CO)-
(L)(jS-S2COEt) (L = PBu3, PPh3, P(OEt)3, P(OPh)3) [14].
The trithiocarbonato complexes CpFe(CO)2(jS-SCS2R)
have been made by substitution of the iodide ligand of
CpFe(CO)2I by the trithiocarbonate anions RSCS2ꢀ
ðR ¼ Me; Et; PhÞ [15]. The chelated forms, CpFe(CO)-
(j2S,S-S2CSR) were obtained by photolysis of the dicar-
bonyl analogs [15].
Photolyzing THF solutions of complexes 1 in the
absence of added ligand produces the chelate complexes
CpFe(CO)(j2E,S-ECS2Ph) (2) as shown in Eq. (2). The tri-
thiocarbonate ligand of 2a is bonded to the metal through
the two sulfur atoms. In a similar fashion, the dithioseleno-
carbonate ligand of 2b is bonded through the selenium and
sulfur atoms. These dark red complexes are soluble in most
organic solvents, including hydrocarbons.
In continuation of our work on the area of organoiron
complexes containing thio- and selocarbonate ligands, this
paper describes the syntheses and X-ray structures of iron
trithiocarbonate and selenodithiocarbonate complexes.
S
Fe
+
Fe
S
Ph
CO
S
OC
E
OC
E
CO
1
SPh
2
2. Results and discussion
E= S (a), Se (b).
ð2Þ
2.1. Synthesis and characterization
1
Complexes 2 have been characterized by IR, H NMR, as
well as elemental analysis. The IR spectra of 2 in CH2Cl2
show the characteristic mCO absorption in the range of
1947–1954 cmꢀ1. This absorption is similar to those of
The trithio- and the dithioselenocarbonate complexes are
obtained in good yields by the reactions of the iron chalco-
genide complexes (l-Ex)[CpFe(CO)2]2 (E = S; x = 2, 3.
E = Se; x = 1) with PhSC(S)Cl, as shown in Eq. (1).
CpFe(CO)(j2S,E-EC(S)OR) (1941–1957 cmꢀ1
)
[10,11]
and are lower than those of the starting complexes 1. The
latter difference might be attributed to the weak p-acid
character of the chelate trithio- or selenodithio-carbonate
ligand compared to that of carbonyl ligand. Complexes 2
OC
Fe
S
CO
Ph
Fe
Ex
+
Cl
S
OC
1
exhibit H NMR spectra showing a singlet in the range
CO
of 4.65–4.66 ppm for the Cp-protons. This chemical shift
range is lower than that for the corresponding Cp reso-
nances in complexes 1 and is similar to the analogous range
reported for CpFe(CO)(j2S,E-EC(S)OR) complexes (4.63–
4.69 ppm) [10,11].
ð1Þ
S
+
Fe
CO
Fe
Ph
S
OC
E
OC
Cl
CO
1
E= S (a), Se (b).
The orange complex 1a and the brown complex 1b are air
stable as solids and in solution. They are soluble in com-
mon polar organic solvents but insoluble in hydrocarbons.
1
The identities of 1 and 2 have been confirmed by IR, H
NMR spectroscopy, elemental analysis and crystal struc-
ture determination. The H NMR spectra of 1 reveal one
Fig. 1. An ORTEP representation of the structure of CpFe(CO)2-
(jS-SCS2Ph) (1a). The thermal ellipsoids are drawn at the 50% probability
level.
1
singlet in the range of 5.06–5.11 ppm for the Cp-proton res-
onances. These chemical shifts fall within the typical range
reported for analogous thiocarbonato and selenocarbonato
complexes of iron [8–11]. The protons of the phenyl group
appear as two multiplets in the ratio of 3:2, as expected.
The bands at 2050 and 2002 cmꢀ1 in the IR spectrum of
1a are due to m(CO) of the two terminal carbonyl groups.
For 1b, these bands are found at lower wavenumbers
(2040, 1990 cmꢀ1) due to stronger r-donor and/or weaker
p-acceptor properties of the selenodithiocarbonate ligand
compared to the trithiocarbonate ligand. A similar shift
for simple thiocarboxylato versus selenocarboxylato com-
plexes has been reported [2–5].
Fig. 2. An ORTEP representation of the structure of CpFe(CO)2(jSe-
SeCS2Ph) (1b). The thermal ellipsoids are drawn at the 50% probability
level.

3922
M. El-khateeb, A. Roller / Polyhedron 26 (2007) 3920–3924
Table 1
2
˚
Selected bond lengths (A) and bond angles (ꢁ) in CpFe(CO)2(jS-SCS2Ph) (1a), CpFe(CO)2(jSe-SeCS2Ph) (1b) and CpFe(CO)(j Se,S-SeCS2Ph) (2b)
1a
1b
2b
Fe–C1
Fe–C2
Fe–C3
Fe–C4
Fe–C5
Fe–C6
Fe–C7
Fe–S1
S1–C8
S2–C8
S3–C9
S3–C8
C6–O1
C7–O2
2.0871(17)
2.1035(16)
2.1111(16)
2.0960(16)
2.0871(172)
1.7879(16)
1.7831(17)
2.2706(4)
1.7232(16)
1.6379(16)
1.7675(18)
1.7733(16)
1.134(2)
Fe–C1
Fe–C2
Fe–C3
Fe–C4
Fe–C5
Fe–C6
Fe–C7
Fe–Se1
Se1–C8
S2–C8
S1–C8
S1–C9
C6–O1
C7–O2
2.0928(17)
2.0830(19)
2.0840(18)
2.0985(17)
2.1072(17)
1.7783(18)
1.7834(17)
2.3844(3)
1.8908(3)
1.6293(16)
1.7568(17)
1.7692(14)
1.137(2)
Fe–C8
Fe–C9
Fe–C10
Fe–C11
Fe–C12
Fe–C13
Fe–Se1
Fe–S1
Se1–C1
S1–C1
S2–C1
S2–C2
C13–O1
2.070(11)
2.063(12)
2.095(14)
2.045(14)
2.051(14)
1.732(14)
2.3872(18)
2.310(2)
1.800(9)
1.734(9)
1.736(8)
1.792(10)
1.129(16)
1.134(2)
1.133(2)
C6–Fe–C7
C7–Fe–S1
C6–Fe–S1
C8–S1–Fe
C9–S3–C8
S2–C8–S1
S2–C8–S3
S1–C8–S3
94.16(8)
89.86(6)
89.93(5)
110.37(7)
103.73(7)
128.91(9)
123.37(10)
107.72(8)
C6–Fe–C7
C7–Fe–Se1
C6–Fe–Se1
C8–Se1–Fe
C8–S1–C9
S2–C8–Se1
S2–C8–S1
S1–C8–Se1
94.21(8)
89.26(6)
88.95(6)
106.98(5)
104.03(8)
128.14(10)
124.59(10)
107.26(8)
C13–Fe–Se1
C13–Fe–S1
Se1–Fe–S
Se1–C1–S1
Se1–C1–S2
S1–C1–S2
C1–S2–C2
95.8(4)
92.8(4)
77.63(7)
112.8(5)
121.8(5)
125.4(5)
102.2(4)
2.2. Crystal structures
similar to that of 1b. The Fe–S bond length in 2b of
˚
2.310(2) A is longer than that of 1a. The Fe–CO bond
˚
The structures of complexes 1a and 1b are shown in
Figs. 1 and 2, respectively. Selected bond distances and
angles for these complexes are collected in Table 1. These
complexes display a three-legged piano-stool configuration
at Fe. The Fe–C(Cp) and Fe–C(CO) bond lengths in 1a
and 1b are similar to those found in CpFe(CO)2-containing
length of 2b (1.732(14) A) is shorter than the corresponding
lengths observed for 1a and 1b in line with higher p-back
donation from the Fe-d orbitals to the empty p*-orbital
of CO in 2b compared to those of 1a and 1b.
3. Experimental
˚
complexes [5,8–10]. The Fe–S bond distance of 2.2677(4) A
in 1a is comparable to that found in CpFe(CO)2SX com-
plexes [X = SO2CCl3 (2.2803(13) A), CO2Et (2.2675(10)
3.1. General
˚
˚
˚
A), CO-2-C6H4NO2 (2.266(1) A), C(S)O–C6H4Cl (2.2765
All manipulations were performed using standard
Schlenk and inert-atmosphere techniques under an argon
atmosphere. Diethyl ether, hexane, and benzene were dried
over sodium and benzophenone, and were freshly-distilled
under nitrogen prior to use. Dichloromethane was heated
under reflux over P2O5, and was freshly-distilled under
nitrogen prior to use. The compounds (l-Sx)[CpFe(CO)2]2
[1] and (l-Se)[CpFe(CO)2]2 [2] were prepared by previously
published procedures. The iron dimer [CpFe(CO)2]2, the
PhSC(S)Cl precursor, selenium, and sulfur were purchased
from Aldrich and were used as received.
˚
(5) A)] [5,8,16,17]. The Fe–Se bond distance in 1b of
2.3839(4) A is also comparable to that found in CpFe-
(CO)2SeY complexes [Y = SO2Ph (2.394(3) A), CO2Et
(2.3829(8) A), C(S)O-4-C6H4Cl (2.3985(2) A)] [7,10,18].
The crystal structure of 2b is presented in Fig. 3.
Selected bond distances and angles of 2b are listed in Table
˚
˚
˚
˚
˚
1. The Fe–Se bond distance in 2b is 2.3872(18) A, which is
Nuclear magnetic resonance (NMR) spectra were
recorded on a Bruker 400 MHz spectrometer. Chemical
shifts are given in ppm relative to TMS at 0 ppm. Infrared
(IR) spectra were recorded on a Nicolat-Impact 410 FT-IR
spectrometer. Elemental analyses of C, H and S were per-
formed in the Institute of Organic Chemistry, Vienna
University, Austria. Melting points were reported on an
electrothermal melting point apparatus and are uncor-
rected. The photolytic reactions were carried out using a
conventional tungsten lamp (100 W).
Fig. 3. An ORTEP representation of the structure of CpFe(CO)(j2Se,S-
SeCS2Ph) (2b). The thermal ellipsoids are drawn at the 30% probability
level.

M. El-khateeb, A. Roller / Polyhedron 26 (2007) 3920–3924
3923
3.2. General procedure for the preparation of
CpFe(CO)2(jE-ECS2Ph) (1)
for C14H10FeO2S2Se: C, 41.10; H, 2.46; S, 15.67. Found: C,
41.00; H, 2.36; S, 15.71%.
A solution of PhSC(S)Cl (1.20 mmol) in 10.0 mL of
diethyl ether was dropwise added to a solution of the iron
chalcogenides (l-Ex)[CpFe(CO)2]2 (1.00 mmol) in 50.0 mL
of diethyl ether. The deep red solution was stirred for 2 h
under protection of light. The solution was stripped to dry-
ness and the resulting solid was redissolved in a minimum
amount of dichloromethane and introduced to a silica gel
column made up in hexane. Elution with hexane removes
the unreacted PhSC(S)Cl. A red band of the product was
eluted with diethyl ether:hexane solution (1:1 v:v ratio), fol-
lowed by another red band which was also collected and
identified as CpFe(CO)2Cl. The products CpFe(CO)2-
(jE-ECS2Ph) were recrystallized from dichloromethane/
hexane.
3.3. General procedure for the preparation of
CpFe(CO)(j2E,S-ECS2Ph) (2)
A THF solution (30 mL) of CpFe(CO)2(jE-ECS2Ph)
(0.25 mmol) was irradiated under a stream of N2 for
15 min. The colour of the reaction mixture turned from
orange to dark red. The volatile components were removed
by vacuum and the resulting solids were purified by column
chromatography using silica gel columns. The columns
were eluted with (1:5 v:v ratio) of CH2Cl2/hexane to sepa-
rate the products, which were subsequently recrystallized
by slow evaporation of hexane solutions.
3.3.1. CpFe(CO)(j2S,S-SCS2Ph) (2a)
Yield: 75%. m.p. = 121–122 ꢁC. IR (CH2Cl2, cmꢀ1):
1
3.2.1. CpFe(CO)2(jS-SCS2Ph) (1a)
1955(s) (mC”O). H NMR (CDCl3): d 4.64 (s, 5H, C5H5);
Yield: 85%. m.p. = 57–59 ꢁC. IR (CH2Cl2, cmꢀ1):
7.30 (m, 3H, C6H5); 7.51 (m, 2H, C6H5). Anal. Calc. for
C13H10FeOS3: C, 46.71; H, 3.02; S, 28.78. Found: C,
46.31; H, 3.09; S, 27.80%.
1
2044(s), 1999(s) (mC”O). H NMR (CDCl3): d 5.11 (s, 5H,
C5H5); 7.45 (m, 3H, C6H5); 7.55 (m, 2H, C6H5). Anal. Calc.
for C14H10FeO2S3: C, 46.42; H, 2.78; S, 26.55. Found: C,
46.31; H, 2.62; S, 26.80%.
3.3.2. CpFe(CO)(j2S,Se-SeCS2Ph) (2b)
Yield: 78%. m.p. = 98–99 ꢁC. IR (CH2Cl2, cmꢀ1):
1
3.2.2. CpFe(CO)2(jSe-SeCS2Ph) (1b)
2049(s) (mC”O). H NMR (CDCl3): d 4.61 (s, 5 H, C5H5);
Yield: 83%. m.p. = 130–131 ꢁC. IR (CH2Cl2, cmꢀ1):
7.48 (m, 3H, C6H5). Anal. Calc. for C13H10FeOS2Se: C,
40.96; H, 2.64; S, 16.83. Found: C, 41.25; H, 2.62; S,
15.21%.
1
2038(s), 1993(s) (mC”O). H NMR (CDCl3): d 5.14 (s, 5H,
C5H5); 7.48 (m, 3H, C6H5); 7.56 (m, 2H, C6H5). Anal. Calc.
Table 2
Crystallographic data and refinement details for CpFe(CO)2(jS-SCS2Ph) (1a), CpFe(CO)2(jSe-SeCS2Ph) (1b), and CpFe(CO)(j2Se,S-SeCS2Ph) (2b)
Compound
1a
1b
2b
Empirical formula
Formula weight
Crystal size (mm)
Crystal system
Space group
Volume (A )
Z
Unit cell dimensions
C
362.25
14H10FeO2S3
C14H10FeO2S2Se
409.15
0.40 · 0.30 · 0.28
monoclinic
P21/c
C13H10FeOS2Se
381.14
0.30 · 0.14 · 0.12
monoclinic
P21/c
0.60 · 0.40 · 0.40
monoclinic
P21/c
1464.56(7)
4
3
˚
1488.16(9)
4
1423.32(11)
4
˚
a (A)
10.3722(3)
12.0814(4)
11.7589(3)
96.320(1)
ꢀ14 6 h 6 14,
ꢀ17 6 k 6 17,
ꢀ16 6 l 6 16
4302/181
736
1.643
1.453
0.71073
0.0267
10.3802(4)
12.0808(4)
11.9470(4)
96.626(2)
ꢀ14 6h 6 14,
ꢀ17 6 k 6 17,
ꢀ16 6 l 6 16
4348/181
808
1.826
3.735
0.71073
0.0218
14.6540(6)
8.1790(4)
12.8734(5)
112.710(2)
ꢀ17 6 h 6 17,
ꢀ9 6 k 6 9,
ꢀ15 6 l 6 15
2504/163
752
1.779
3.893
0.71073
0.0817
˚
b (A)
˚
c (A)
b (ꢁ)
Index ranges
Data/parameters
F(000)
Dcalc (g/cm3)
l (mmꢀ1
)
˚
k (A)
R1a
wRb2
0.0796
1.036
0.0551
1.016
0.2780
1.057
Goodness-of-fitc
P
P
a
R1 = iFoj ꢀ jFci/ jFoj.
P
P
2
2
1=2
b
c
wR2 ¼ f ½wðF 2o ꢀ F c2Þ ꢁ= ½wðF 2oÞ ꢁg
.
P
Goodness-of-fit ¼ f ½wðF 2o ꢀ F c2Þ ꢁ=ðn ꢀ pÞg1=2, where n is the number of reflections and p is the total number of parameters refined.
2

3924
M. El-khateeb, A. Roller / Polyhedron 26 (2007) 3920–3924
3.4. X-ray crystal structure analysis
Acknowledgements
Details of data collections and structure refinement for
complexes 1a, 1b and 2b are collected in Table 2. Single
crystals suitable for X-ray structure determination were
obtained by re-crystallization of 1a and 1b from THF/
hexane mixtures, and from hexane for 2b. X-ray diffrac-
tion measurements were performed on X8APEXII CCD
diffractometer with graphite monochromated Mo Ka
M.E. thanks the Jordan University of Science and Tech-
nology for financial support and the Alexander von Hum-
boldt Foundation for a scholarship. We thank Prof. V.
Arion for his help in the crystallographic analysis.
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˚
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[11] M. El-khateeb, Polyhedron 25 (2006) 1387.
[12] M. Moran, I. Cuadrado, J.R. Masaguer, J. Losada, C. Foces-Foces,
F.H. Cano, Inorg. Chim. Acta 143 (1988) 59.
[13] M. Moran, I. Cuadrado, C. Munoz-Reja, J.R. Masaguer, J. Losada,
J. Chem. Soc., Dalton Trans. (1988) 149.
[14] M. Moran, I. Cuadrado, J.R. Masaguer, J. Losada, J. Organomet.
Chem. 352 (1987) 255.
[15] R. Bruce, G. Knox, J. Organomet. Chem. 6 (1966) 67.
[16] Bruker Programs, SAINT-NT, version 6.0; SAINT, version 7.12A;
SADABS, version 2.10; XPREP, version 5.1, Bruker AXS Inc., Madison,
WI, USA, 2003.
4. Supplementary material
[17] G.M. Sheldrick, SHELXS97: Program for Crystal Structure Solution,
University of Go¨ttingen, Germany, 1997.
[18] G.M. Sheldrick, SHELXL97: Program for Crystal Structure Refine-
ment, University of Go¨ttingen, Germany, 1997.
[19] C.K. Johnson, Report ORNL-5138, OAK Ridge National Labora-
tory, OAK Ridge, TN, 1976.
[20] International Tables for X-ray Crystallography; vol. C. Kluwer
Academic Press, Dodrecht, The Netherlands, 1992. Tables 4.2.6.8 and
6.1.1.4.
CCDC 632056, 632055 and 632057 contain the supple-
mentary crystallographic data for 1a, 1b and 2b. These data
can be obtained free of charge via http://www.ccdc.ac.uk/
conts/retrieving.html, or from the Cambridge Crystallo-
graphic Data Centre, 12 Union Road, Cambridge CB2
1EZ, UK; fax: (+44) 1223-336-033; or e-mail:
deposit@ccdc.cam.ac.uk.