The first selenosulfonate complexes CpFe(CO)2SeSO2R: Preparation and structure of CpFe(CO)2SeSO2C6H5

Article abstract of DOI:10.1016/S0277-5387(01)00831-2

Treatment of the iron selenide (μ-Se)[CpFe(CO)₂]₂ with sulfonyl chlorides RSO₂Cl (R = C₆H₅ (1), 4-C₆H₄Cl (2), 4-C₆H₄Br (3), 4-C₆H^t

Full text of DOI:10.1016/S0277-5387(01)00831-2

Polyhedron 20 (2001) 2393–2396
www.elsevier.com/locate/poly
The first selenosulfonate complexes CpFe(CO)2SeSO2R:
preparation and structure of CpFe(CO)2SeSO2C6H5
Mohammad El-khateeb *, Tara Obidate
Chemistry Department, Faculty of Science, Jordan Uni6ersity of Science and Technology, PO Box 3030, Irbid 22110, Jordan
Received 29 January 2001; accepted 2 May 2001
Abstract
Treatment of the iron selenide (m-Se)[CpFe(CO)2]2 with sulfonyl chlorides RSO2Cl (R=C6H5 (1), 4-C6H4Cl (2), 4-C6H4Br (3),
4-C6Ht4Bu (4), 4-C6H4Me (5), CH3 (6)) gave the novel iron selenosulfonato complexes CpFe(CO)2SeSO2R in good yields. The
crystal structure for 1 was determined. © 2001 Elsevier Science Ltd. All rights reserved.
Keywords: Iron; Selenosulfonato; Carbonyl; Selenium; Crystal structure
1. Introduction
In spite of the increasing number of reports which
describe the synthesis and characterization of
organometallic selenide complexes, those describing
their reactivity are still very limited. The reaction of the
organoiron selenides, (m-Sex)[Cp%Fe(CO)2]2 where
Cp%=C5H5, Bu–C5H4, Bu2C5H3, with acid chlorides
has been reported to give selenocarboxylate complexes
[12]. Recent studies in our laboratory have shown that
the reaction of the iron sulfides (m-Sx)[CpFe(CO)2]2
(x=3, 4) with sulfonyl chlorides gave the correspond-
ing thiosulfonato complexes, CpFe(CO)2SSO2R, in
good yields [22]. Here we report the extension of this
work to the reaction of the iron selenide analog, (m-
Se)[CpFe(CO)2]2, with sulfonyl chlorides in attempts to
prepare a novel selenosulfonato complexes.
The chemistry of transition metal–selenium com-
plexes is of current interest due to their important
biological and catalytic aspects [1–5]. Recently, sele-
nium has been found in a surprising number of proteins
and enzymes [4,5]. Moreover, organometallic selenium
complexes have many industrial importances, such as
solid state precursors [6–9], and solar energy technol-
ogy [7,10,11].
Transition metal selenide complexes have attracted
extensive interest in recent years [12–19]. Studies have
been focused on the preparation and characterization
of simple neutral binuclear selenium bridged complexes
of the type LnM–Sex–MLn. The reaction of
organometallic dimers with elemental selenium repre-
sents a successful route for the syntheses of such se-
lenides. Accordingly, the reaction of [Cp%M(CO)2]2 with
elemental selenium gave (m-Sex)[Cp%M(CO)2]2 where
Cp%=C5H5, tBu–C5H4, tBu2C5H3; M=Fe; x=1–4
[12,13], M=Ru; x=5 [14], and Cp%=C5Me5; M=
Mo, W; x=3, 4 [15]. The tungsten selenides (m-
Sex)[CpW(CO)3]2 where x=2, 3, 4, have been prepared
by the reaction of the anion, LiCpW(CO)3, with ele-
mental selenium [16]. The complex (m-Se2)[Fe(CO)3]2
has been prepared and characterized also [17–21].
t
t
2. Experimental
All experiments were performed under N2 atmo-
sphere using Schlenk techniques [23]. Benzene, di-
ethylether
and
hexane
were
distilled
over
sodium/benzophenone under N2 prior to use. Methyl-
ene chloride was distilled over P2O5. The reagents,
[CpFe(CO)2]2, selenium and sulfonyl chlorides (Acros)
were used as received. Iron selenide (m-Se)[CpFe(CO)2]2
was prepared as described in the literature [12].
* Corresponding author. Tel.: +962-2-7095-111x23644; fax:
+962-2-7095-014.
E-mail address: kateeb@just.edu.jo (M. El-khateeb).
Nuclear magnetic resonance (NMR) spectra were
recorded on a JEOL-270 spectrophotometer. Samples
0277-5387/01/$ - see front matter © 2001 Elsevier Science Ltd. All rights reserved.
PII: S0277-5387(01)00831-2

2394
M. El-khateeb, T. Obidate / Polyhedron 20 (2001) 2393–2396
were prepared under nitrogen. Chemical shifts are in
ppm relative to TMS at 0 ppm. Infrared (IR) spectra
were recorded on a Nicolate 410-Impact Fourier-trans-
form spectrophotometer. Elemental analyses were per-
C13H10FeO4SSe: C, 39.32; H, 2.54; S, 8.08. Found: C,
39.20; H, 2.31; S, 8.02%.
2.1.2. CpFe(CO)2SeSO2-4-C6H4Cl (2)
´
Yield=82%.
M.p.=116–117 °C.
1H
NMR
formed by Laboratoire d’Analyse Ele´mentaire,
University of Montre´al, Montre´al, Que´bec, Canada.
Melting points were measured on an electrothermal
melting point apparatus and are uncorrected.
(CDCl3): l 5.23 (s, 5H, Cp); 7.44 (d, 2H, Ph); 7.80 (m,
2H, Ph). IR (CH2Cl2, cm−1) w(CO): 2043, 1997, (KBr)
w(SO): 1261, 1122. Anal. Calc. for C13H9ClFeO4SSe: C,
36.18; H, 2.10; S, 7.43. Found: C, 35.98; H, 1.95; S,
7.24%.
2.1. General procedure for the preparation of
CpFe(CO)2SeSO2R
2.1.3. CpFe(CO)2SeSO2-4-C6H4Br (3)
A 100-ml Schlenk flask was charged with the iron
sulenide (m-Se)[CpFe(CO)2]2 (0.43 g, 1 mmol) and dis-
solved in 50 ml of diethyl ether. The sulfonyl chloride
(1.2 mmol) was added via a syringe. The resulting
mixture was stirred overnight. The solvent was removed
under vacuum and redissolved in a minimum amount
of methylene chloride. This solution was introduced to
a silica gel column made up in hexane. Elution with
hexane get red of the excess sulfonyl chlorides. Elution
with a mixture of methylene chloride and hexane (1:1
volume ratio) gave a brownish band which was col-
lected and identified as CpFe(CO)2SeSO2R, followed by
a red band which was also collected and identified as
CpFe(CO)2Cl. The CpFe(CO)2SeSO2R complexes were
recrystallized from CH2Cl2/hexane.
Yield=80%.
M.p.=126–128 °C.
1H
NMR
(CDCl3): l 5.24 (s, 5H, Cp); 7.46 (d, 2H, Ph); 7.74 (d,
2H, Ph). IR (CH2Cl2, cm−1) w(CO): 2040, 1998, (KBr)
w(SO): 1262, 1122. Anal. Calc. for C13H9BrFeO4SSe: C,
32.80; H, 1.91; S, 6.74. Found: C, 32.62; H, 1.67; S,
6.52%.
2.1.4. CpFe(CO)2SeSO2-4-C6Ht4Bu (4)
1
Yield=60%. M.p.=82–83 °C. H NMR (CDCl3):
t
l 1.18 (s, 9H, Bu); 5.16 (s, 5H, Cp); 7.25 (d, 2H, Ph);
7.80 (m, 2H, Ph). IR (CH2Cl2, cm−1) w(CO): 2038,
1997, (KBr) w(SO): 1262, 1117. Anal. Calc. for
C17H18FeO4SSe: C, 45.06; H, 4.00; S, 7.07. Found: C,
44.81; H, 3.95; S, 6.78%.
2.1.5. CpFe(CO)2SeSO2-4-C6H4Me (5)
2.1.1. CpFe(CO)2SeSO2C6H5 (1)
Yield=85%.
M.p.=103–104 °C.
1H
NMR
Yield=77%.
M.p.=119–120 °C.
1H
NMR
(CDCl3): l 2.37 (s, 3H, Me); 5.19 (s, 5H, Cp); 7.24 (d,
2H, Ph); 7.75 (m, 2H, Ph). IR (CH2Cl2, cm−1) w(CO):
2038, 1999, (KBr) w(SO): 1262, 1115. Anal. Calc. for
C14H12FeO4SSe: C, 40.91; H, 2.94; S, 7.08. Found: C,
40.79; H, 2.78; S, 7.31%.
(CDCl3): l 5.23 (s, 5H, Cp); 7.46 (m, 3H, Ph); 7.95 (m,
2H, Ph). IR (CH2Cl2, cm−1) w(CO): 2042, 1993, (KBr)
w(SO): 1261 (m), 1121 (m). Anal. Calc. for
Table 1
Selected crystal data and refinement parameters for CpFe(CO)2-
SeSO2C6H5 (1)
2.1.6. CpFe(CO)2SeSO2Me (6)
Yield=60%. M.p.=98–99 °C. H NMR (CDCl3):
1
l 3.34 (s, 3H, Me); 5.22 (s, 5H, Cp). IR (CH2Cl2,
cm−1) w(CO): 2037, 1993, (KBr) w(SO): 1263, 1115.
Anal. Calc. for C8H8FeO4SSe: C, 28.69; H, 2.41; S,
9.57. Found: C, 27.98; H, 2.43; S, 9.03%.
Empirical formula
Formula weight
Crystal size (mm)
Crystal system
C13H10FeO4SSe
397.08
0.38×0.33×0.22
orthorhombic
Pbca
Space group
Unit cell dimensions
2.2. Crystallographic analysis
,
a (A)
11.192(13)
12.132(12)
20.93(2)
2842(5)
,
b (A)
,
c (A)
Single crystals suitable for X-ray were obtained by
recrystallization of 1 from CH2Cl2/hexane mixtures.
The crystallographic data are shown in Table 1. The
measurements were at 293(2) K on a Nonius CAD-4
diffractometer. Unit cell parameters were determined
from 25 reflections (17BqB23°). There were 2702
independent reflections with 1493 observed reflections
(\2|(I)). The structure was solved by direct method
using SHELXS-97 [24] and DIFMAP synthesis using
SHELXTL-96 [25]. All non-hydrogen atoms are an-
isotropic. Hydrogen atoms are isotropic.
3
,
V (A )
Z
8
Index ranges
Dcalc (Mg m−3
Radiation type
−13BhB13, −14BkB14, −25BlB25
1.8559
)
Cu Ka
12.908
1.54056
17.00–23.00
0.0511
v (mm−1
)
,
u (A)
q Range (°)
R[F2\2|(F2)]
ꢀR(F2) a
0.1266
a ꢀ=1/[|2(F2)+(0.0802P)2], where P=(Fo2+2Fc2)/3.

M. El-khateeb, T. Obidate / Polyhedron 20 (2001) 2393–2396
2395
ligands in the ranges 1261–1263 and 1115–1122 cm−1
.
These SO bands are similar to those obtained for
CpRu(PP)SSO2R (PP=dppm, dppe) [26], and for com-
plexes containing the sulfinato (RSO2) group [27–29].
1
The H NMR spectra of 1–6 show a singlet due to the
cyclopentadienyl ligand protons in the range 5.19–5.24
ppm. This peak is higher than that observed for the
thiocarboxylate complexes CpFe(CO)2SCOR (5.08–
5.11 ppm) [12] and similar to that of the thiosulfonato
complexes CpFe(CO)2SSO2R (5.21–5.28 ppm) [22].
These IR and NMR spectral results reflect a relatively
lower electron density around the iron atom in com-
plexes 1–6 compared to that of the selenocarboxylates,
CpFe(CO)2SeCOR and higher than that of the thiosul-
fonates, CpFe(CO)2SSO2R.
The reactivity of the metal selenide towards sulfonyl
chlorides may attributed to the presence of the electron-
rich selenium atom. We found that the iron sulfides
(m-Sx)[CpFe(CO)2]2 react only with strong electrophilic
sulfonyl chlorides and this was attributed to the strong
S–S bond in the sulfide bridge complexes [22]. In
contrast to this, the iron selenide (m-Se)[CpFe(CO)2]2
react with moderate electrophilic sulfonyl chlorides
(R=CH3, C6H5, 4-ClC6H4, 4-BrC6H4, 4-CH3C6H4) to
give selenosulfonate complexes. However, the reaction
of the iron selenide with strong electrophilic sulfonyl
chlorides (R=2,5-(NO2)2C6H3, CF3, CCl3, C6F5) re-
sults only in the formation of the complex
CpFe(CO)2Cl and no selenosulfonate was isolated. The
selenosulfonates produced from the later sulfonyl chlo-
rides are highly unstable and decomposed during the
course of the reaction.
Fig. 1. ORTEP drawing of CpFe(CO)2SeSO2C6H5 (1). Selected bond
,
length (A) and angles (°): Fe–C1=2.105(8), Fe–C2=2.079(8), Fe–
C3=2.070(8), Fe–C4=2.105(8), Fe–C5=2.130(7), Fe–C6=
1.778(9), Fe–C7=1.778(8), Fe–Se=2.394(3), Se–S=2.201(3),
S–O1=1.453(6), S–O2=1.442(6), C6–Fe–Se=94.4(3), C7–Fe–
Se=85.9(3), S–Se–Fe=107.58(9), O–S–O=118.0(4), C6–Fe–
C7=94.9.
3. Results and discussion
Novel iron selenosulfonato complexes CpFe(CO)2-
SeSO2R have been prepared from the reaction of the
iron selenide (m-Se)[CpFe(CO)2]2 with sulfonyl chlorides
RSO2Cl (R=C6H5, 4-C6H4Cl, 4-C6H4Br, 4-C6Ht4Bu,
4-C6H4Me, CH3) in diethyl ether at room temperature
(Eq. (1)). The complex CpFe(CO)2Cl was also obtained
from this reaction as a side product. These two prod-
ucts were separated by column chromatography using
1:1 volume ratio of methylene chloride/hexane as elu-
ent. To the best of our knowledge, complexes 1–6 are
the first transition metal complexes containing the se-
lenosulfonato ligand.
The structure of 1 was determined and is shown in
Fig. 1. The compound has an Fe–Se bond length of
,
2.394(3) A which is shorter than the Fe–Se bond found
i
,
in Fe(Se-2,6- Pr2C6H3)2L2 (L=PMe2Ph: 2.421 A, L=
,
1/2Et2PCH2CH2PPh2: 2.415 A, L=1-methylimidazole:
2.444 A) [30,31]. The Se–S bond length (2.201(3) A) is
also longer than the S–S bond of CpFe(CO)2SSO2CCl3
,
,
,
(2.022(2) A). The S–O bond lengths (1.453(6) and
,
1.442(6) A) are similar to those observed for
(1)
CpFe(CO)2SSO2CCl3 and those for complexes of the
type CpRu(PPh3)(CO)E where E=SS(O)CH2Ph,
SS(O)CHMe2 and SS(O)2-4-C6H4Me [32,33].
The selenosulfonato complexes 1–6 are air stable as
solids and sensitive in solutions. They are soluble in
common organic solvents and insoluble in hexanes.
1
They were characterized by IR, H NMR spectroscopy
4. Supplementary material
and elemental analysis. The IR spectra of 1–6 contain
two strong bands in the ranges 2038–2043 and 1993–
1999 cm−1 corresponding to the stretching frequencies
of the two terminal carbonyl ligands. These bands are
higher than those of the corresponding selenocarboxy-
lates, CpFe(CO)2SeCOR (2030–2035, 1965–1973
cm−1) and lower than those for the thiosulfonates,
CpFe(CO)2SSO2R (2047–2064, 1991–1998 cm−1). The
spectra also contain two bands for the selenosulfonato
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC No. 155388. Copies of this infor-
mation may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge, CB2
1EZ, UK (fax: +44-1233-336-033; e-mail: deposit@
ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).

2396
M. El-khateeb, T. Obidate / Polyhedron 20 (2001) 2393–2396
[15] H. Brunner, J. Wachter, H. Wintergerst, J. Organomet. Chem.
Acknowledgements
235 (1982) 77.
[16] P.G. Jones, C. Thone, Inorg. Chem. 35 (1996) 6625.
[17] P. Muthar, M. Hossain, K. Das, U.C. Sintta, J. Chem. Soc.,
Chem. Commun. (1993) 46.
[18] P. Muthar, M. Hossain, K. Das, U.C. Sintta, Organometallics 12
(1993) 2393.
The authors thank the Deanship of Research, Jordan
University of Science & Technology for financial sup-
port, grant no. 106/2000. Mrs. F. Be´langer-Garie´py
(University of Montre´al) is greatly thanked for deter-
mining the X-ray structure.
[19] P. Muthar, M. Hossain, K. Das, U.C. Sintta, M. Mahon, J.
Organomet. Chem. 471 (1994) 185.
[20] W.J. Evans, G.W. Rabe, J.W. Ziller, R.J. Doedens, Inorg.
Chem. 33 (1994) 2719.
[21] D.Y. Chung, S.P. Huang, K.-W. Kim, M.G. Kanatzides, Inorg.
Chem. 34 (1995) 4292.
References
[22] M. El-khateeb, A. Shaver, A.-M. Lebius, J. Organomet. Chem.
622 (2001) 293.
[1] J. Arnold, Prog. Inorg. Chem. 43 (1995) 353.
[2] D. Coucouvanis, Acc. Chem. Res. 24 (1991) 1.
[3] R.R. Chianelli, Catal. Rev. Sci. Engl. 26 (1984) 361.
[4] T.C. Standtman, Annu. Rev. Biochem. 59 (1990) 111.
[5] F. Ursini, Biol. Chim. Biophys. Acta 62 (1985) 839.
[6] M. Bochmann, A.P. Colman, K.J. Webb, M.B. Hursthouse, M.
Mazid, Angew. Chem., Int. Ed. Engl. 30 (1991) 973.
[7] W. Hirpo, S. Dhingra, A.C. Sutorik, M.G. Kanatzidis, J. Am.
Chem. Soc. 115 (1993) 1597.
[23] D. Shriver, M. Drezdzon, The Manipulation of Air Sensitive
Compounds, 2nd ed., Wiley Interscience, Toronto, 1986.
[24] G.M. Sheldrick, SHELXS-97, Program for the Solution of Crystal
Structures, University of Go¨ttingen, Germany, 1997.
[25] G.M. Sheldrick, SHELXL-96, Program for the Refinement of
Crystal Structures, University of Go¨ttingen, Germany, 1996.
[26] M. El-khateeb, B. Wolfsberger, W.A. Schenk, J. Organomet.
Chem. 612 (2000) 14.
[8] M.G. Kanatzidis, S.P. Huang, Coord. Chem. Rev. 130 (1994)
509.
[27] W.A. Schenk, J. Frisch, W. Adam, F. Prechtl, Inorg. Chem. 31
(1992) 3329.
[9] M. Bochmann, K.J. Webb, J.E. Hails, D. Wolverson, Eur. J.
Solid State Inorg. Chem. 29 (1992) 155.
[28] S.L. Miles, D.L. Miles, R. Bau, T.C. Flood, J. Am. Chem. Soc.
100 (1976) 7279.
[10] C.X. Qin, I. Shih, Phosphorus Sulfur Relat. Elem. 38 (1988) 409.
[11] Y. Park, G. Kanatzidis, Chem. Mater 3 (1991) 781.
[12] I. Jibril, O. Abu-Nimreh, Synth. React. Inorg. Met.-Org. Chem.
26 (1996) 1409.
[29] T.C. Flood, F.J. Disanti, D.L. Miles, Inorg. Chem. 15 (1976)
1910.
[30] C.E. Forde, R.H. Morris, R. Ramachandran, Inorg. Chem. 33
(1994) 5647.
[13] W.A. Herman, J. Rohrmann, H. Hecht, J. Organomet. Chem.
290 (1985) 53.
[31] C.E. Forde, A.J. Lough, R.H. Morris, R. Ramachandran, Inorg.
Chem. 35 (1996) 2747.
[14] I. Jibril, F.T. Esmadi, H. El-Masri, L. Zsolnai, G. Huttner, J.
Organomet. Chem. 510 (1996) 109.
[32] A. Shaver, P.-Y. Plouffe, Inorg. Chem. 33 (1992) 4327.
[33] A. Shaver, P.-Y. Plouffe, J. Am. Chem. Soc. 113 (1991) 7780.
.