General synthetic route to double-butterfly Fe/S cluster complexes via reactions of the dianions {[(μ-CO)Fe2 (CO)6]2(μ-SZS-μ)}2- with electrophiles

Article abstract of DOI:10.1021/om034208f

A simple and convenient route for the synthesis of linear and macrocyclic double-butterfly Fe/S cluster complexes has been developed, which involves a sequential reaction of Fe₃-(CO)₁₂ with the dithiol HSZSH in the presence of Et₃N, followed by treatment of the intermediate [Et₃NH]⁺ salts of dianions {[(μ-CO)Fe₂(CO)₆]₂ (μ-SZS-μ)}^2- (4) with electrophiles. For example, treatment of the [Et₃NH]⁺ salts of dianions 4 with allyl bromide and PhSBr produces the linear complexes [(μ-CH₂=CHCH₂) Fe₂(CO)₆]₂(μ-SZS-μ) (5a, Z = (CH₂)₄; 5b, Z = CH₂(CH₂ OCH₂)₂; 5c, Z = CH₂(CH₂ OCH₂)₃CH₂) and [(μ-PhS)Fe₂ (CO)₆]₂(μ-SZS-μ) (6a, Z = CH₂ (CH₂OCH₂)₂CH₂; 6b, Z = CH₂(CH₂OCH₂)₃CH₂), whereas treatment with S₂Cl₂ and ClSZSCl yields the macrocyclic complexes [Fe₂(CO)₆]₂(μ-S-S-μ)(μ-SZS-μ) (7a, Z = CH₂(CH₂OCH₂)₂CH₂; 7b, Z = CH₂(CH₂OCH₂)₃CH₂) and [Fe₂(CO)₆]₂(μ-SZS-μ)₂ (8a, Z = CH₂(CH₂OCH₂)₂CH₂; 8b, Z = CH₂(CH₂OCH₂)₃CH₂), respectively. In addition, while the [Et₃NH]⁺ salts of dianions 4 react in situ with PhNCS and SCN(CH₂)₄NCS to give the linear complexes [(μ-PhNHC=S)Fe₂(CO)₆]₂(μ-SZS-μ) (9a, Z = CH₂CH₂OCH₂CH₂; 9b, Z = CH₂(CH₂OCH₂)₂CH₂; 9c, Z = CH₂(CH₂OCH₂)₃CH₂) and macrocyclic complexes [Fe₂(CO)₆]₂[μ-S=CNH(CH₂) ₄NHC=S-μ](μ-SZS-μ) (10a, Z = (CH₂)₄; 10b, Z = CH₂(CH₂OCH₂)₂ CH₂), the in situ reactions with PhC≡CPh and PhC≡CH afford the linear complexes [(μ-σ,π-PhCH=CPh)Fe₂ (CO)₆]₂(μ-SZ S-μ) (11a, Z = CH₂ (CH₂OCH₂)₂CH₂; 11b, Z = CH₂(CH₂OCH₂)₃CH₂) and [(μ-σ,π-PhCH=CH)Fe₂(CO)₆]₂(μ-SZS -μ) (12a, Z = (CH₂)₄; 12b, Z = CH₂ (CH₂OCH₂)₂CH₂; 12c, Z = CH₂(CH₂OCH₂)₃CH₂). The possible pathways for production of these linear and macrocyclic cluster complexes are suggested, and their structures have been characterized by elemental analysis and IR and ¹H NMR spectroscopy, as well as for 5a, 7a, 8a, and 12a by X-ray diffraction analysis.

Full text of DOI:10.1021/om034208f

Organometallics 2004, 23, 823-831
823
Gen er a l Syn th etic Rou te to Dou ble-Bu tter fly F e/S
Clu ster Com p lexes via Rea ction s of th e Dia n ion s
{[(µ-CO)F e2(CO)6]2(µ-SZS-µ)}2- w ith Electr op h iles†
Li-Cheng Song,* Feng-Hua Gong, Tao Meng, J ian-Hua Ge, Li-Na Cui, and
Qing-Mei Hu
Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry,
Nankai University, Tianjin 300071, China
Received October 1, 2003
A simple and convenient route for the synthesis of linear and macrocyclic double-butterfly
Fe/S cluster complexes has been developed, which involves a sequential reaction of Fe3-
(CO)12 with the dithiol HSZSH in the presence of Et3N, followed by treatment of the
intermediate [Et3NH]+ salts of dianions {[(µ-CO)Fe2(CO)6]2(µ-SZS-µ)}2- (4) with electrophiles.
For example, treatment of the [Et3NH]+ salts of dianions 4 with allyl bromide and PhSBr
produces the linear complexes [(µ-CH2dCHCH2)Fe2(CO)6]2(µ-SZS-µ) (5a , Z ) (CH2)4; 5b, Z
) CH2(CH2OCH2)2CH2; 5c, Z ) CH2(CH2OCH2)3CH2) and [(µ-PhS)Fe2(CO)6]2(µ-SZS-µ) (6a ,
Z ) CH2(CH2OCH2)2CH2; 6b, Z ) CH2(CH2OCH2)3CH2), whereas treatment with S2Cl2 and
ClSZSCl yields the macrocyclic complexes [Fe2(CO)6]2(µ-S-S-µ)(µ-SZS-µ) (7a , Z ) CH2(CH2-
OCH2)2CH2; 7b, Z ) CH2(CH2OCH2)3CH2) and [Fe2(CO)6]2(µ-SZS-µ)2 (8a , Z ) CH2(CH2OCH2)2-
CH2; 8b, Z ) CH2(CH2OCH2)3CH2), respectively. In addition, while the [Et3NH]+ salts of
dianions 4 react in situ with PhNCS and SCN(CH2)4NCS to give the linear complexes [(µ-
PhNHCdS)Fe2(CO)6]2(µ-SZS-µ) (9a , Z ) CH2CH2OCH2CH2; 9b, Z ) CH2(CH2OCH2)2CH2;
9c, Z ) CH2(CH2OCH2)3CH2) and macrocyclic complexes [Fe2(CO)6]2[µ-SdCNH(CH2)4NHCd
S-µ](µ-SZS-µ) (10a , Z ) (CH2)4; 10b, Z ) CH2(CH2OCH2)2CH2), the in situ reactions with
PhCtCPh and PhCtCH afford the linear complexes [(µ-σ,π-PhCHdCPh)Fe2(CO)6]2(µ-SZS-
µ) (11a , Z ) CH2(CH2OCH2)2CH2; 11b, Z ) CH2(CH2OCH2)3CH2) and [(µ-σ,π-PhCHdCH)-
Fe2(CO)6]2(µ-SZS-µ) (12a , Z ) (CH2)4; 12b, Z ) CH2(CH2OCH2)2CH2; 12c, Z ) CH2(CH2-
OCH2)3CH2). The possible pathways for production of these linear and macrocyclic cluster
complexes are suggested, and their structures have been characterized by elemental analysis
1
and IR and H NMR spectroscopy, as well as for 5a , 7a , 8a , and 12a by X-ray diffraction
analysis.
In tr od u ction
particular interest. This is because that they might be
expected, like double-tetrahedral MoFeCoS clusters,12
to have new chemical reactivity patterns through the
interactions between the two subcluster cores or, like
double-cubane MoFe3S4 clusters,13 to become a new class
of biologically relevant molecules. Previously, Seyferth’s
group and we reported a series of double-butterfly Fe/S
cluster complexes, for instance 1-3, which were pre-
pared by reactions of (µ-S2)Fe2(CO)6 with alkyllithium
Butterfly Fe/S cluster complexes have recently at-
tracted growing interest, because of their novel chem-
istry1 and the closely related biological relevance to the
active site of the Fe-only hydrogenases.2 Among them,
the double-butterfly Fe/S cluster complexes3-11 are of
* To whom correspondence should be addressed. Fax: 0086-22-
23504853. E-mail: lcsong@nankai.edu.cn.
† Dedicated to Professor Dietmar Seyferth, on the occasion of his
75th birthday and in recognition of his outstanding contributions to
Organometallic Chemistry.
(4) Seyferth, D. Kiwan, A. M. J . Organomet. Chem. 1985, 286, 219.
(5) Song, L.-C.; Kadiata, M.; Wang, J .-T.; Wang, R.-J .; Wang, H.-G.
J . Organomet. Chem. 1988, 340, 239.
(6) Song, L.-C.; Kadiata, M.; Hu, Q.-M.; Wang, J .-T. Acta Chim. Sin.
(Engl. Ed.) 1988, 203.
(7) Song, L.-C.; Kadiata, M.; Wang, J .-T.; Wang, R.-J .; Wang, H.-G.
J . Organomet. Chem. 1990, 391, 387.
(8) Song, L.-C.; Yan, C.-G.; Hu, Q.-M.; Wang, R.-J .; Mak, T. C. W.
Organometallics 1995, 14, 5513.
(9) Song, L.-C.; Yan, C.-G.; Hu, Q.-M.; Wang, R.-J .; Mak, T. C. W.;
Huang, X.-Y. Organometallics 1996, 15, 1535.
(10) Song, L.-C.; Lu, G.-L.; Hu, Q.-M.; Yang, J .; Sun, J . J . Orga-
nomet. Chem. 2001, 623, 56.
(11) Bose, K. S.; Sinn, E.; Averill, B. A. Organometallics 1984, 3,
1126.
(12) Song, L.-C.; Guo, D.-S.; Hu, Q.-M.; Huang, X.-Y. Organo-
metallics 2000, 19, 960.
(13) Kovacs, J . A.; Bashkin, J . K.; Holm, R. H. J . Am. Chem. Soc.
1985, 107, 1784.
(1) For reviews, see for example: (a) Ogino, H.; Inomata, S.; Tobita,
H. Chem. Rev. 1998, 98, 2093. (b) Song, L.-C. In Advances in
Organometallic Chemistry; Huang, Y., Qian, Y. Eds.; Chemical Indus-
try Press: Beijing, 1987; p 181. (c) Song, L.-C. In Trends in Organo-
metallic Chemistry, Atwood, J . L., Corriu, R., Cowley, A. H., Lappert,
M. F., Nakamura, A., Pereyre, M., Eds.; Research Trends: Trivandrum,
India, 1999; Vol. 3, p 1.
(2) (a) Gloaguen, F.; Lawrence, J . D.; Rauchfuss, T. B. J . Am. Chem.
Soc. 2001, 123, 9476. (b) Gloaguen, F.; Lawrence, J . D.; Schmidt, M.;
Wilson, S. R.; Rauchfuss, T. B. J . Am. Chem. Soc. 2001, 123, 12518.
(c) Lyon, E. J .; Georgakaki, I. P.; Reibenspies, J . H.; Darensbourg, M.
Y. J . Am. Chem. Soc. 2001, 123, 3268. (d) Ott, S.; Kritikos, M.;
Åkermark, B.; Sun, L. Angew. Chem., Int. Ed. 2003, 42, 3285. (e)
Darensbour, M. Y.; Lyon, E. J .; Zhao, X.; Georgakaki, I. P. PNAS 2003,
100, 3683. (f) Razavet, M.; Davies, S. C.; Hughes, D. L.; Barclay, J . E.;
Evans, D. J .; Fairhurst, S. A.; Liu, X.; Pickett, C. J . Dalton 2003, 586.
(3) Seyferth, D.; Kiwan, A. M.; Sinn, E. J . Organomet. Chem. 1985,
281, 111.
10.1021/om034208f CCC: $27.50 © 2004 American Chemical Society
Publication on Web 01/16/2004

824 Organometallics, Vol. 23, No. 4, 2004
Song et al.
Sch em e 1
Sch em e 2
or Grignard reagents and subsequent treatment of
Resu lts a n d Discu ssion
the S-centered monoanions (µ-RS)(µ-S-)Fe2(CO)6 with
4-7
Syn t h esis a n d Ch a r a ct er iza t ion of [(µ-CH 2d
CHCH2)F e2(CO)6]2(µ-SZS-µ) (5a -c). The [Et3NH]+
salts of dianions 4 (Z ) (CH2)4, CH2(CH2OCH2)2,3CH2)
(generated from Fe3(CO)12, HSZSH, and Et3N) reacted
in situ with an excess of allyl bromide in THF at room
temperature (through nucleophilic attack of the two
negatively charged Fe atoms of 4 at two molecules of
allyl bromide followed by displacement of the two µ-CO
ligands in intermediate m 1) to produce the series of
double-butterfly cluster complexes 5a -c (Scheme 2).
organic or inorganic halides (Scheme 1).
Another synthetic route to double-butterfly Fe/S
cluster complexes has also been developed. It involves
the reactions of a new type of double-butterfly, two
µ-CO-containing dianions {[(µ-CO)Fe2(CO)6]2(µ-SZS-
µ)}2- (4) with electrophiles, such as Ph2PCl and PhC-
(O)Cl.14 To further develop the chemistry of novel
dianions 4 and to see if this route has generality for the
synthesis of double-butterfly Fe/S cluster compounds,
we carried out the reactions of dianions 4 with other
types of electrophiles, such as CH2dCHCH2Br, S2Cl2,
PhNdCdS, PhCtCH, SCN(CH2)2NCS, etc. As a result,
a series of linear and cyclic double-butterfly Fe/S cluster
complexes were produced. It follows that the route
involving dianions 4 is indeed a general route suitable
for synthesizing a wide variety of double-butterfly Fe/S
cluster complexes. Now, we report the interesting
results obtained from this study.
Products 5a -c are red air-stable materials, whose
elemental analysis and spectroscopic data are consistent
with the structures shown in Scheme 2. The H NMR
1
spectra of 5a -c showed the CH2 proton signals of the
allyl ligands as two doublets at ca. 0.5 ppm (J ≈ 12 Hz)
and ca. 2 ppm (J ≈ 6 Hz), corresponding to the anti and
syn hydrogens. An ORTEP drawing of 5a is shown in
Figure 1. Table 1 lists selected bond lengths and angles.
Compound 5a is a centrosymmetric double-butterfly
cluster complex, in which two identical butterfly Fe2-
SC3 subcluster cores are joined together through its two
(14) (a) Song, L.-C.; Fan, H.-T.; Hu, Q.-M. J . Am. Chem. Soc. 2002,
124, 4566. (b) Song, L.-C.; Fan, H.-T.; Hu, Q.-M.; Yang, Z.-Y.; Sun, Y.;
Gong, F.-H. Chem. Eur. J . 2003, 9, 170.

Double-Butterfly Fe/ S Cluster Complexes
Organometallics, Vol. 23, No. 4, 2004 825
F igu r e 1. ORTEP drawing of 5a with atom-labeling scheme.
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 5a
Fe(1)-C(1)
Fe(1)-C(7)
Fe(1)-S(1)
Fe(1)-C(8)
Fe(1)-Fe(2)
1.771(5)
2.110(4)
2.2232(14)
2.429(4)
2.6530(12)
Fe(2)-C(9)
Fe(2)-S(1)
S(1)-C(10)
C(7)-C(8)
C(8)-C(9)
2.096(4)
2.2181(13)
1.800(4)
1.383(6)
1.403(6)
C(7)-Fe(1)-S(1)
C(7)-Fe(1)-C(8)
S(1)-Fe(1)-C(8)
C(7)-Fe(1)-Fe(2) 89.34(13) C(8)-C(9)-Fe(2)
S(1)-Fe(1)-Fe(2) 53.23(3) C(9)-Fe(2)-Fe(1)
C(8)-Fe(1)-Fe(2) 59.16(11) S(1)-Fe(2)-Fe(1)
86.96(13) Fe(2)-S(1)-Fe(1)
34.56(14) C(7)-C(8)-Fe(1)
82.24(11) C(9)-C(8)-Fe(1)
73.36(5)
60.0(2)
114.0(3)
89.7(3)
85.92(13)
53.41(4)
S atoms by a butylene group. The two S atoms attached
to the butylene group are bound symmetrically across
the two iron atoms (Fe(1)-S(1) ) 2.2232(14) Å; Fe(2)-
S(1) ) 2.2181 (13) Å), as are the two terminal carbon
atoms in each of the allyl ligands (Fe(1)-C(7) ) 2.110
(4) Å; Fe(2)-C(9) ) 2.096 (4) Å). The C-C bond lengths
of the allyl ligands (C(7)-C(8) ) 1.383(6) Å; C(8)-C(9)
) 1.403(6) Å) lie between the values reported for C-C
single and double bonds, indicating that the ligands are
best regarded as delocalized π-allyl ligands.15 In addi-
tion, the dihedral angle between two wings of each
butterfly subcluster core is 87.4° and the butylene bridge
is connected to S atoms (the angle C(10)-S(1)‚‚‚C(8) )
160.9°) by an equatorial type of bond.16 In fact, the basic
geometry of the subcluster cores in this double-butterfly
cluster complex is very similar to that of the single-
butterfly cluster complex (µ-EtS)(µ-CH2dCHCH2)Fe2-
(CO)6.17
Syn th esis a n d Ch a r a cter iza tion of [(µ-P h S)F e2-
(CO)6]2(µ-SZS-µ) (6a ,b), [F e2(CO)6]2(µ-S-S-µ)(µ-SZS-
µ) (7a ,b), a n d [F e2(CO)6]2(µ-SZS-µ)2 (8a ,b). While the
[Et3NH]+ salts of dianions 4 (Z ) CH2(CH2OCH2)2,3CH2)
reacted with PhSBr in THF at room temperature
(through nucleophilic attack of the two negatively
charged Fe atoms of 4 at two molecules of PhSBr and
subsequent displacement of the two µ-CO ligands in
intermediate m 2) to give the linear double-butterfly
F igu r e 2. ORTEP drawing of 7a with atom-labeling
scheme.
complexes 6a ,b, they reacted with S2Cl2 and ClSZSCl
(Z ) CH2(CH2OCH2)2,3CH2) under similar conditions
(through double nucleophilic attack of the two nega-
tively charged Fe atoms of 4 at one molecule of S2Cl2 or
ClSZSCl followed by loss of two µ-CO ligands from
intermediate m 3 or m 4) to afford the macrocyclic cluster
complexes 7a ,b and 8a ,b, respectively (Scheme 3).
Products 6a ,b, 7a ,b, and 8a ,b may be regarded as
new types of acyclic and cyclic cluster crown ethers,
which have been characterized by elemental analyses
1
and IR and H NMR spectroscopy, as well as for 7a and
8a by X-ray diffraction analyses. While the 1H NMR
spectra of 6a ,b, 7a ,b, and 8a ,b displayed the corre-
sponding H-containing organic groups, their IR spectra
exhibited several absorption bands in the range 2081-
1966 cm-1 for their terminal carbonyls and one absorp-
tion band in the region 1128-1116 cm-1 for their ether
chain functionalities.
Figure 2 shows the molecular structure of 7a ,
and Table 2 displays its bond lengths and angles. As
can be seen in Figure 2, complex 7a contains the
two butterfly subcluster cores Fe(1)Fe(2)S(1)S(3) and
Fe(3)Fe(4)S(2)S(4), which are connected by an S(1)-S(2)
bond and the ether chain C(13)C(14)O(13)C(15)C(16)-
O(14)C(17)C(18) to afford a 16-membered macrocycle.
(15) MacGillavry, C. H., Rieck, G. D., Eds. International Tables for
X-ray Crystallography; Kynoch Press: Birmingham, England, 1974;
Vol. III, p 276.
(16) (a) Seyferth, D.; Henderson, R. S.; Song, L.-C. Organometallics
1982, 1, 125. (b) Shaver, A.; Fitzpatrick, P. J .; Steliou, K.; Butler, I. S.
J . Am. Chem. Soc. 1979, 101, 1313.
(17) Seyferth, D. Womack, G. B.; Dewan, J . C. Organometallics 1985,
4, 398.

826 Organometallics, Vol. 23, No. 4, 2004
Song et al.
Sch em e 3
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 7a
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 8a
Fe(1)-C(1)
Fe(1)-C(2)
Fe(1)-S(1)
Fe(2)-S(1)
Fe(1)-Fe(2)
1.808(6)
1.800(7)
2.239(2)
2.2428(18)
2.5103(16)
Fe(1)-S(3)
Fe(2)-S(3)
Fe(3)-S(4)
Fe(3)-Fe(4)
S(1)-S(2)
2.286(2)
Fe(1)-C(1)
Fe(1)-S(1)
Fe(2)-S(1)
Fe(1)-S(2A)
Fe(1)-Fe(2)
1.793(7)
Fe(2)-S(2A)
S(1)-C(7)
S(2)-C(12)
Fe(2)-C(4)
S(2)-Fe(1A)
2.2592(19)
1.838(6)
1.842(6)
1.788(7)
2.2601(18)
2.2802(18)
2.2581(19)
2.5304(17)
2.118(2)
2.2468(19)
2.2541(19)
2.2601(18)
2.5130(14)
S(1)-Fe(1)-S(3)
S(1)-Fe(1)-Fe(2)
S(3)-Fe(1)-Fe(2)
S(4)-Fe(4)-S(2)
S(4)-Fe(4)-Fe(3)
S(2)-S(1)-Fe(1)
78.30(5) S(1)-Fe(2)-S(3)
56.01(4) S(1)-Fe(2)-Fe(1)
56.55(4) S(2)-Fe(3)-S(4)
80.86(5) S(2)-Fe(3)-Fe(4)
55.95(5) Fe(1)-S(1)-Fe(2)
111.78(7) S(2)-S(1)-Fe(2)
78.34(7)
55.87(6)
80.89(6)
55.96(6)
68.12(5)
113.78(7)
C(1)-Fe(1)-S(1)
S(1)-Fe(1)-S(2A)
C(1)-Fe(1)-Fe(2)
S(1)-Fe(1)-Fe(2)
S(2A)-Fe(1)-Fe(2)
94.1(2)
S(1)-Fe(2)-S(2A)
80.32(7)
55.92(5)
56.23(5)
114.6(2)
67.88(6)
80.46(6) S(1)-Fe(2)-Fe(1)
102.8(2)
56.20(5) C(7)-S(1)-Fe(1)
56.20(5) Fe(1)-S(1)-Fe(2)
S(2A)-Fe(2)-Fe(1)
also lengthened compared to the S-S bond (2.108(3) Å)
of the linear double cluster complex [(µ-PhS)Fe2(CO)6]2-
(µ-S-S-µ),3 obviously due to formation of its 16-
membered ring, in which the ether chain pulls the two
butterfly Fe2S2 cluster cores closer and thus makes the
S-S bond longer.
The molecular structure of 8a is shown in Figure 3,
and its bond lengths and angles are displayed in
Table 3. Similar to 7a , product 8a is composed of the
two butterfly cluster cores Fe(1)Fe(2)S(1)S(2A) and
Fe(1A)Fe(2A)S(2)S(1A) linked together by the two
ether chains C(7)C(8)O(7)C(9)C(10)O(8)C(11)C(12) and
C(7A)C(8A)O(7A)C(9A)C(10A)O(8A)C(11A)C(12A) to form
a 24-membered macrocycle. The heteroatom distances
In addition, the ether chain is bound to S(3) by the axial
bond C(13)-S(3) (the angle C(13)-S(3)‚‚‚S(1) ) 77.9°)
and to S(4) by the equatorial bond C(18)-S(4) (the angle
C(18)-S(4)‚‚‚S(2) ) 158.0°), whereas the subcluster core
Fe(1)Fe(2)S(1)S(3) is bonded to S(2) by its equatorial
bond (the angle S(2)-S(1)‚‚‚S(3) ) 159.1°) and the
subcluster core Fe(3)Fe(4)S(2)S(4) to S(1) by its axial
bond (the angle S(1)-S(2)‚‚‚S(4) ) 74.4°),16 respectively.
The S-S bond (2.118(2) Å) of 7a is lengthened from the
single S-S bond (2.037(5) Å) in elemental sulfur.18 It is
(18) Anderson, E. L.; Fehlner, T. P.; Foti, A. E.; Salahub, D. R. J .
Am. Chem. Soc. 1980, 102, 7422.

Double-Butterfly Fe/ S Cluster Complexes
Organometallics, Vol. 23, No. 4, 2004 827
Sch em e 4
S(1)-S(1A), S(2)-S(2A), O(7)-O(7A), and O(8)-O(8A)
are in the range 7.122-8.815 Å. While one ether chain
is bonded to S(1) and S(2) by the equatorial bond C(7)-
S(1) (the angle C(7)-S(1)‚‚‚S(2A) ) 158.8°) and axial
bond C(12)-S(2) (the angle C(12)-S(2)‚‚‚S(1A) ) 79.8°),
the other ether chain is bound to S(1A) and S(2A) by
the equatorial bond C(7A)-S(1A) (the angle C(7A)-
S(1A)‚‚‚S(2) ) 158.5°) and axial bond C(12A)-S(2A) (the
angle C(12A)-S(2A)‚‚‚S(1) ) 79.8°),16 respectively. How-
ever, in contrast to 7a , product 8a has two identical
ether chains, whose structure is centrosymmetric. To
our knowledge, both 7a and 8a are so far the first
crystallographically characterized cyclic double-butterfly
Fe2S2 clusters.
afford the double-butterfly cluster compounds 9a -c,
whereas the [Et3NH]+ salts of dianions 4 (Z ) (CH2)4,
CH2(CH2OCH2)2CH2) reacted with diisothiocyanate
SCN(CH2)4NCS under similar conditions to yield the
macrocyclic double-butterfly clusters 10a ,b (Scheme 4).
Clusters 9a -c might be suggested as being derived from
nucleophilic attack of the two negatively charged Fe
atoms of 4 at the central C atoms of two molecules of
PhNCS followed by loss of two µ-CO ligands of dianions
m 5 and protonation of the N-centered dianions m 6 by
Syn th esis a n d Ch a r a cter iza tion of [(µ-P h NHCd
S)Fe2(CO)6]2(µ-SZS-µ) (9a-c), [Fe2(CO)6]2[µ-SdCNH-
(CH 2)4NHCdS-µ](µ-SZS-µ) (10a ,b), [(µ-σ,π-P h CH d
CP h )Fe2(CO)6]2(µ-SZS-µ) (11a,b), an d [(µ-σ,π-P h CHd
CH)F e2(CO)6]2(µ-SZS-µ) (12a -c). We further found
that the [Et3NH]+ salts of dianions 4 not only reacted
with the electrophiles having one and two leaving
groups to produce the linear and cyclic double-butterfly
clusters of types 5-8 as described above, but also they
could react with the electrophiles that have no leaving
group to yield the corresponding linear and cyclic
double-butterfly clusters. For example, the [Et3NH]+
salts of 4 (Z ) CH2(CH2OCH2)1-3CH2) reacted with
phenyl isothiocyanate in THF at room temperature to
F igu r e 3. ORTEP drawing of 8a with atom-labeling
scheme.

828 Organometallics, Vol. 23, No. 4, 2004
Song et al.
Sch em e 5
the counterion [Et3NH]+; similarly, clusters 10a ,b could
be regarded as produced through nucleophilic attack of
the two negatively charged Fe atoms of 4 at the central
C atoms in two NdCdS functional groups of one
molecule of the diisothiocyanate followed by loss of
two µ-CO ligands from dianions m 7 and protonation of
the N-centered dianions m 8 by the [Et3NH]+ cation
(Scheme 4).
Clusters 9a -c and 10a ,b have been characterized by
elemental analysis and spectroscopy. For example, while
their 1H NMR spectra showed one singlet at about 9
ppm for 9a -c and about 7 ppm for 10a ,b assigned to
their NH groups, their IR spectra displayed one absorp-
tion bond in the range 940-1026 cm-1 for their coordi-
nated thiocarbonyl CdS groups.19 In fact, the formation
of PhNHCdS and SdCHN(CH2)4NHCdS ligands in the
above-mentioned reactions could be strongly supported
by the crystal structure of the single-butterfly cluster
(µ-p-MeC6H4Se)(µ-PhCH2NHCdS)Fe2(CO)6, produced
from reaction of the [Et3NH]+ salt of the monoanion [(µ-
p-MeC6H4Se)(µ-CO)Fe2(CO)6 ]- with PhCH2NCS.20
Similarly, the [Et3NH]+ salts of dianions 4 (Z )
(CH2)4, CH2(CH2OCH2)2,3CH2) reacted with diphenyl-
acetylene and phenylacetylene in refluxing THF to give
the double-butterfly cluster complexes 11a ,b and 12a -
c, respectively (Scheme 5).
Apparently, 11a ,b were presumably formed by nu-
cleophilic attack of the two negatively charged Fe atoms
in 4 at the triply bonded C atoms of two molecules of
diphenylacetylene, followed by loss of two µ-CO ligands
from the C-centered dianions m 9 and protonation of
another C-centered dianion m 10 by the [Et3NH]+ cation;
similarly, 12a -c might be produced by protonation of
the C-centered danions m 12 by the [Et3NH]+ cation,
which were formed by nucleophilic attack of the two
negatively charged Fe atoms of 4 at â-C atoms of two
phenylacetylene molecules (both steric considerations
and the ability of the phenyl group to stabilize R-carb-
anions favor â-attack of the iron nucleophile), followed
by loss of two µ-CO ligands from the initially formed
C-centered dianions m 11 (Scheme 5).
1
In the H NMR spectra of complexes 11a ,b and 12a -
c, the endo-PhCH signals for 11a ,b are overlapped with
their CH2O signals as a multiplet from 3.6 to 3.7 ppm,
whereas the endo-PhCH signals for 12a -c are found
as an upfield doublet (δH ∼4.3 ppm, J trans ≈ 13 Hz) and
the endo-FeCH signals for 12a -c appear as a low-field
doublet (δH ∼8.4 ppm, J trans ≈ 13 Hz). These data agree
with the corresponding data reported by Seyferth and
King the for single-butterfly complexes (µ-σ,π-PhCHd
CH)(µ-tBuS)Fe2(CO)6,21 (µ-σ,π-PhCHdCPh)(µ-tBuS)Fe2-
(19) (a) Patin, H.; Magnani, G.; Mahe´, C.; Le Marouille, J .-Y.;
Southern, T. G.; Benoit, A.; Grandjean, D. J . Organomet. Chem. 1980,
197, 315. (b) Song, L.-C.; Yan, C.-G.; Hu, Q.-M.; Wu, B.-M.; Mak, T. C.
W. Organometallics 1997, 16, 632.
(20) Song, L.-C.; Lu, G.-L.; Hu, Q.-M.; Fan, H.-T.; Chen, J .; Sun, J .;
Huang, X.-Y. J . Organomet. Chem. 2001, 627, 255.

Double-Butterfly Fe/ S Cluster Complexes
Organometallics, Vol. 23, No. 4, 2004 829
ing angle in 5a (87.4°) and the subcluster cores are also
linked through S atoms by an equatorial type of bond16
(the angle C(15)-S(1)‚‚‚C(7) ) C(15A)-S(1A)‚‚‚C(7A) )
151.4°).
Exp er im en ta l Section
Gen er a l Com m en ts. All reactions were carried out under
an atmosphere of prepurified nitrogen by using standard
Schlenk and vacuum-line techniques. Tetrahydrofuran (THF)
was distilled from Na/benzophenone ketyl under nitrogen and
bubbled for ca. 30 min before use. Fe3(CO)12,23 HSZSH (Z )
(CH2)4, CH2(CH2OCH2)nCH2 (n ) 1-3)),24 PhSBr,25 ClSZSCl
(Z ) CH2(CH2OCH2)nCH2 (n ) 2, 3)),26 SCN(CH2)4NCS,27 and
PhCtCH28 were prepared according to literature procedures.
CH2dCHCH2Br, S2Cl2, and PhNCS were of commercial origin
and used without further purification. Preparative TLC was
carried out on glass plates (25 × 15 × 0.25) coated with silica
gel G (10-40 µm). IR spectra were recorded on a Bio-Rad FTS
F igu r e 4. ORTEP drawing of 12a with atom-labeling
scheme.
Ta ble 4. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 12a
1
135 infrared spectrophotometer. H NMR spectra were taken
on a Bruker AC-P200 NMR spectrometer. C/H analyses were
performed with an Elementar Vario EL analyzer. Melting
points were determined on a Yanaco MP-500 apparatus and
were uncorrected.
Fe(1)-C(8)
Fe(1)-S(1)
Fe(1)-Fe(2)
Fe(2)-C(7)
Fe(3)-S(2)
2.235(6)
Fe(3)-Fe(4)
Fe(4)-S(2)
S(1)-C(15)
C(7)-C(8)
C(8)-C(9)
2.5517(13)
2.2563(17)
1.824(5)
1.393(8)
1.502(8)
2.2737(17)
2.5395(14)
1.974(6)
Sta n d a r d in Situ P r ep a r a tion of th e [Et3NH]+ Sa lts of
Dia n ion s {[(µ-CO)F e2(CO)6]2(µ-SZS-µ)}2- (4‚[Et3NH]2). A
100 mL three-necked flask fitted with a magnetic stir bar, a
rubber septum, and a nitrogen inlet tube was charged with
1.00 g (2.0 mmol) of Fe3(CO)12, 30 mL of THF, 1.0 mmol of
HSZSH (Z ) (CH2)4, CH2(CH2OCH2)nCH2 (n ) 1-3)) and 0.28
mL (2.0 mmol) of Et3N. The mixture was stirred at room
temperature for 45 min to give a brown-red solution of ca. 1
mmol of the intermediate salts 4‚[Et3NH]2, which was utilized
immediately in the following preparations.
2.2751(17)
S(1)-Fe(1)-Fe(2)
S(1)-Fe(2)-Fe(1)
C(7)-C(8)-C(9)
C(7)-C(8)-Fe(1)
C(9)-C(8)-Fe(1)
S(2)-Fe(3)-Fe(4)
55.43(5) S(2)-Fe(4)-Fe(3)
56.28(5) Fe(2)-S(1)-Fe(1)
126.2(6)
65.5(3)
121.3(4)
55.38(5) Fe(2)-C(7)-Fe(1)
56.08(5)
68.28(5)
68.54(5)
127.9(4)
77.1(3)
Fe(4)-S(2)-Fe(3)
C(8)-C(7)-Fe(2)
C(8)-C(7)-Fe(1)
77.4(2)
(CO)6,21 and (µ-σ,π-CH2dCH)(µ-RS)Fe2(CO)6.22 Thus,
1
from the H NMR data for the vinyl ligand in double-
P r ep a r a tion of [(µ-CH2dCHCH2)F e2(CO)6]2[µ-S(CH2)4S-
µ] (5a ). To the above-prepared solution of 4‚[Et3NH]2 (Z )
(CH2)4) was added 0.70 mL (8.0 mmol) of CH2dCHCH2Br, and
the mixture was stirred at room temperature for 16 h. The
solvent was removed under reduced pressure. The residue was
subjected to TLC separation using CH2Cl2/petroleum ether (1/4
v/v) as eluent. From the main red band, 0.190 g (25%) of 5a
was obtained as a red solid, mp 125 °C dec. Anal. Calcd for
cluster complexes 11a ,b and 12a -c, it was determined
that overall addition of the diiron unit and the proton
to the two molecules of acetylenes occurred in a cis
fashion. This is completely consistent with the addition
mode between the [Et3NH]+ salts of single-butterfly
anions [(µ-RS)(µ-CO)Fe2(CO)6]- and acetylenes to form
the corresponding single-butterfly complexes (µ-σ,π-R1-
CHdCR2)(µ-RS)Fe2(CO)6.21
C
22H18Fe4O12S2: C, 34.68; H, 2.38. Found: C, 34.45; H, 2.28.
IR (KBr disk): νCtO 2059 (vs), 2025 (vs), 1965 (vs) cm-1 1H
.
The molecular structure of 12a is shown in Figure 4,
while selected bond lengths and angles are presented
in Table 4. Complex 12a , similar to 5a , is also a
centrosymmetric double-butterfly cluster complex, which
contains two butterfly Fe2SC2 subcluster cores coupled
together by a butylene group. However, in contrast to
5a , the two S atoms attached to the butylene group and
the two C atoms of substituted vinyl ligands in 12a
are asymmetrically bonded to the two iron atoms
(Fe(1)-S(1) ) 2.2737(17) Å; Fe(2)-S(1) ) 2.2509(17) Å;
Fe(1)-C(8) ) 2.235(6) Å; Fe(2)-C(7) ) 1.974(6) Å). It
is noteworthy that the C-C bond length of the substi-
tuted vinyl ligand (C(7)-C(8) ) 1.393(8) Å) is obviously
longer than the normal value for a C-C double bond,
which demonstrates that the C-C double bond in each
of the substituted vinyl ligands is coordinated to the two
iron atoms in a σ,π-manner (Fe(2)-C(7) σ-bond length
1.974(6) Å; Fe(1)-C(7) and Fe(1)-C(8) π-bond lengths
2.087(6) and 2.235(6) Å, respectively). Finally, it is also
worth noting that the dihedral angle between the two
butterfly wings Fe(2)-Fe(1)-S(1) and Fe(1)-Fe(2)-
C(7)-C(8) (109.5°) is much larger than the correspond-
NMR (200 MHz, CDCl3): 0.48 (d, J ) 11.9 Hz, 4H, 4 anti-
FeCHH), 1.69 (s, 4H, CH2CH2CH2CH2), 1.98 (d, J ) 5.6 Hz,
4H, 4 syn-FeCHH), 2.44 (s, 4H, 2CH2S), 4.70-4.85 (m, 2H, 2
allylic CH) ppm.
P r ep a r a t ion of [(µ-CH 2dCH CH 2)F e2(CO)6]2[µ-SCH 2-
(CH2OCH2)2CH2S-µ] (5b). The same procedure was followed
as for 5a , but 4‚[Et3NH]2 (Z ) CH2(CH2OCH2)2CH2) was used.
From the main red band, 0.259 g (32%) of 5b was obtained as
a red oil. Anal. Calcd for C24H22Fe4O14S2: C, 35.07; H, 2.70.
Found: C, 34.48; H, 2.96. IR (KBr disk): νCtO 2061 (s), 2020
(vs), 1950 (vs); νC-O-C 1110 (m) cm-1 1H NMR (200 MHz,
.
CDCl3): 0.51 (d, J ) 10.2 Hz, 4H, 4 anti-FeCHH), 1.97 (d, J )
6.1 Hz, 4H, 4 syn-FeCHH), 2.65 (s, 4H, 2CH2S), 3.62 (s, 8H,
4CH2O), 4.60-5.05 (m, 2H, 2 allylic CH) ppm.
P r ep a r a tion of [(µ-CH2dCHCH)F e2(CO)6]2[µ-SCH2-
(CH2OCH2)3CH2S-µ] (5c). The same procedure was followed
as for 5a , but 4‚[Et3NH]2 (Z ) CH2(CH2OCH2)3CH2) was
utilized. From the main red band, 0.208 g (24%) of 5c was
(23) King, R. B. Organometallic Syntheses, Transition-Metal Com-
pounds; Academic Press: New York, 1965; Vol. I, p 95.
(24) (a) Martin, D. J .; Greco, C. C. J . Org. Chem. 1968, 33, 1275. (b)
Pedersen, C. J . J . Am. Chem. Soc. 1967, 89, 7017.
(25) Harpp, D. N.; Mathiaparanam, P. J . Org. Chem. 1972, 37, 1367.
(26) Morris. J . L.; Rees, C. W.; J . Chem. Soc., Perkin Trans. 1 1987,
211.
(21) Seyferth, D.; Hoke, J . B.; Womack, G. B. Organometallics 1990,
9, 2662.
(27) Martha, W., Ed. The Merck Index, 11th ed.; Merck: Rahway,
NJ , 1988; p 293.
(22) King, R. B.; Treichel, P. M.; Stone, F. G. A. J . Am. Chem. Soc.
1961, 83, 3600.
(28) Hessler, J . C. Organic Syntheses; Wiley: New York, 1955;
Collect. Vol. 3, p 438.

830 Organometallics, Vol. 23, No. 4, 2004
Song et al.
obtained as a red oil. Anal. Calcd for C26H26Fe4O15S2: C, 36.06;
(200 MHz, CDCl3): 2.32-2.68 (m, 8H, 4CH2S), 3.38-3.87 (m,
24H, 12CH2O) ppm.
H, 3.02. Found: C, 36.00; H, 2.95. IR (KBr disk): νCtO 2061
1
(s), 2016 (vs), 1955 (vs); νC-O-C 1108 (m) cm-1. H NMR (200
P r ep a r a tion of [(µ-P h NHCdS)F e2(CO)6]2(µ-SCH2CH2-
OCH2CH2S-µ) (9a ). To the above-prepared solution of 4‚[Et3-
NH]2 (Z ) CH2CH2OCH2CH2) was added 0.24 mL (2.0 mmol)
of PhNdCdS, and the mixture was stirred at room tempera-
ture for 12 h. Solvent was removed under reduced pressure.
The residue was subjected to TLC separation. Acetone/
petroleum ether (1/4 v/v) eluted the first main red band, which
gave 0.387 g (40%) of 9a as an orange solid, mp 68-70 °C.
Anal. Calcd for C30H20Fe4N2O13S4: C, 37.22; H, 2.08; N, 2.89.
Found: C, 37.21; H, 2.11; N, 2.85. IR (KBr disk): νCtO 2065
(vs), 2024 (vs), 1989 (vs); νN-H 3380 (m); νC-O-C 1107 (m); νCdS
MHz, CDCl3): 0.49 (d, J ) 12.5 Hz, 4H, 4 anti-FeCHH), 1.98
(d, J ) 5.6 Hz, 4H, 4 syn-FeCHH), 2.62-2.67 (m, 4H, 2CH2S),
3.63 (s, 12H, 6CH2O), 4.70-4.85 (m, 2H, 2 allylic CH) ppm.
P r ep a r a tion of [(µ-P h S)F e2(CO)6]2[µ-SCH2(CH2OCH2)2-
CH2S-µ] (6a ). To the above-prepared solution of 4‚[Et3NH]2
(Z ) CH2(CH2OCH2)2CH2) was added 0.378 g (2.0 mmol) of
PhSBr, and the mixture was stirred at room temperature for
12 h. Solvent was removed under reduced pressure. The
residue was subjected to TLC separation using CH2Cl2/
petroleum ether (1/1 v/v) as eluent. From the main red band,
0.342 g (36%) of 6a was obtained as a red solid, mp 146 °C
1
943 (w) cm-1. H NMR (200 MHz, CDCl3): 2.86-2.94 (m, 4H,
dec. Anal. Calcd for
C
30H22Fe4O14S4: C, 37.61; H, 2.31.
2CH2S), 3.93 (t, J ) 6.4 Hz, 4H, 2CH2O), 7.24-7.31 (m, 10H,
2C6H5), 8.73 (s, 2H, 2NH) ppm.
Found: C, 37.53; H, 2.25. IR (KBr disk): νCtO 2070 (s), 2032
1
(vs), 1990 (vs), 1968 (vs); νC-O-C 1125 (s) cm-1. H NMR (200
P r ep a r a tion
of [(µ-P h NHCdS)F e2(CO)6]2[µ-SCH2-
MHz, CDCl3): 2.52 (t, J ) 6.4 Hz, 4H, 2CH2S), 3.50-3.62 (m,
8H, 4CH2O), 7.13-7.24 (m, 10H, 2C6H5) ppm.
(CH2OCH2)2CH2S-µ] (9b). The same procedure was followed
as for 9a , but 4‚[Et3NH]2 (Z ) CH2(CH2OCH2)2CH2) was
utilized. The residue was subjected to TLC separation using
acetone/petroleum ether (1/10 v/v) as eluent. From the main
red band, 0.705 g (70%) of 9b was obtained as an orange solid,
mp 68-71 °C. Anal. Calcd for C32H24Fe4N2O14S4: C, 37.97; H,
2.39; N, 2.77. Found: C, 37.85; H, 2.48; N, 3.04. IR (KBr
disk): νCtO 2064 (vs), 2024 (vs), 1989 (vs); νN-H 3379 (m); νC-O-C
1113 (m); νCdS 940 (w) cm-1. 1H NMR (200 MHz, CDCl3): 2.80
(s, 4H, 2CH2S), 3.63-3.85 (m, 8H, 4CH2O), 7.26 (s, 10H,
2C6H5), 8.69 (s, 2H, 2NH) ppm.
P r ep a r a tion of [(µ-P h S)F e2(CO)6]2[µ-SCH2(CH2OCH2)3-
CH2S-µ] (6b). The same procedure was followed as for 6a , but
4‚[Et3NH]2 (Z ) CH2(CH2OCH2)3CH2) was used. From the
main red band, 0.410 g (41%) of 6b was obtained as a red oil.
Anal. Calcd for C32H26Fe4O15S4: C, 38.35; H, 2.61. Found: C,
38.22; H, 2.55. IR (KBr disk): νCtO 2071 (s), 2033 (vs), 1993
1
(vs); νC-O-C 1116 (m) cm-1. H NMR (200 MHz, CDCl3): 2.56
(s, 4H, 2 CH2S), 3.58 (s, 12H, 6CH2O), 7.24 (s, 10H, 2C6H5)
ppm.
P r epar ation of [Fe2(CO)6]2(µ-S-S-µ)[µ-SCH2(CH2OCH2)2-
CH2S-µ] (7a ). To the above-prepared solution of 4‚[Et3NH]2
(Z ) CH2(CH2OCH2)2CH2) was added 0.16 mL (2.0 mmol) of
S2Cl2, and the mixture was stirred at room temperature for 4
h. Solvent was removed under reduced pressure. The residue
was subjected to TLC separation using acetone/petroleum
ether (1/10 v/v) as eluent. From the main red band, 0.103 (13%
yield) of 7a was obtained as a red solid, mp 155 °C dec. Anal.
Calcd for C18H12Fe4O14S4: C, 26.89; H, 1.50. Found: C, 26.85;
H, 1.45. IR (KBr disk): νCtO 2080 (s), 2067 (s), 2045 (vs), 2022
P r ep a r a tion
of [(µ-P h NHCdS)F e2(CO)6]2[µ-SCH2-
(CH2OCH2)3CH2S-µ] (9c). The same procedure was followed
as for 9a , but 4‚[Et3NH]2 (Z ) CH2(CH2OCH2)3CH2) was
employed. From the main red band, 0.698 g (66%) of 9c was
obtained as an orange solid, mp 55-57 °C. Anal. Calcd for
34H28Fe4N2O15S4: C, 38.66; H, 2.67; N, 2.65. Found: C, 38.74;
H, 2.78; N, 3.04. IR (KBr disk): νCtO 2064 (vs), 2024 (vs), 1988
(vs); νN-H 3379 (m); νC-O-C 1111 (m); νCdS 941 (w) cm-1 1H
NMR (200 MHz, CDCl3): 2.84 (s, 4H, 2CH2S), 3.65-3.95 (m,
12H, 6CH2O), 7.30 (s, 10H, 2C6H5), 8.74 (s, 2H, 2NH) ppm.
P r ep a r a tion of [F e2(CO)6]2[µ-SdCNH(CH2)4NHCdS-µ]-
(µ-S(CH2)4S-µ) (10a ). To the above-prepared solution of 4‚
[Et3NH]2 (Z ) (CH2)4) was added 0.172 g (1.0 mmol) of
SCN(CH2)4NCS, and the mixture was stirred at room temper-
ature for 12 h. Solvent was removed under reduced pressure.
The residue was subjected to TLC separation using acetone/
petroleum ether (1/1 v/v) as eluent. From the main red band,
0.146 g (17%) of 10a was obtained as a red oil. Anal. Calcd for
C
.
1
(vs), 1998 (vs), 1980 (vs); νC-O-C 1127 (m) cm-1. H NMR (200
MHz, CDCl3): 2.24-2.30, 2.70-2.75 (m, m, 4H, 2CH2S), 3.27-
3.78 (m, 8H, 4CH2O) ppm.
P r epar ation of [Fe2(CO)6]2(µ-S-S-µ)[µ-SCH2(CH2OCH2)3-
CH2S-µ] (7b). The same procedure was followed as for 7a , but
4‚[Et3NH]2 (Z ) CH2(CH2OCH2)3CH2) was employed. From the
main red band, 0.149 g (18% yield) of 7b was obtained as a
red solid, mp 148 °C dec. Anal. Calcd for C20H16Fe4O15S4: C,
28.33; H, 1.90. Found: C, 28.20; H, 1.91. IR (KBr disk): νCtO
2081 (s), 2069 (s), 2046 (vs), 2022 (vs), 1999 (vs), 1980 (vs);
C
22H18Fe4N2O12S4: C, 30.94; H, 2.12; N, 3.28. Found: C, 31.11;
H, 2.19; N, 3.39. IR (KBr disk): νCtO 2069 (v), 2025 (vs), 1963
1
ν
C-O-C 1128 (m) cm-1. 1H NMR (200 MHz, CDCl3): 2.13-2.20,
(vs); νCdS 1026 (m) cm-1. H NMR (200 MHz, CDCl3): 1.35-
2.70-2.79 (m, m, 4H, 2CH2S), 3.26-3.83 (m, 12H, 6CH2O)
ppm.
2.10 (m, 8H, 2CH2CH2CH2CH2), 2.40-2.65 (m, 4H, 2CH2S),
2.80-2.95 (m, 4H, 2CH2N), 6.56 (s, 2H, 2HN) ppm.
P r ep a r a tion of [F e2(CO)6]2[(µ-SCH2(CH2OCH2)2CH2S-
µ)]2 (8a ). After the above-prepared solution of 4‚[Et3NH]2 (Z
) CH2(CH2OCH2)2CH2) was cooled to -10 °C, 0.252 g (1.0
mmol) of ClCH2(CH2OCH2)2CH2SCl was added. The mixture
was stirred at room temperature for 12 h. Solvent was removed
under reduced pressure. The residue was subjected to TLC
separation using acetone/petroleum ether (1/3 v/v) as eluent.
From the main red band, 0.132 g (14%) of 8a was obtained as
a red solid, mp 146-148 °C. Anal. Calcd for C24H24Fe4O16S4:
C, 31.33; H, 2.63. Found: C, 31.19; H, 2.89. IR (KBr disk):
νCtO 2071 (s), 2036 (vs), 1995 (vs), 1966 (vs); νC-O-C 1119 (s)
cm-1. 1H NMR (200 MHz, CDCl3): 2.27-2.71 (m, 8H, 4CH2S),
3.44-3.96 (m, 16H, 8CH2O) ppm.
P r ep a r a tion of [F e2(CO)6]2[µ-SdCNH(CH2)4NHCdS-µ]-
(µ-SCH2(CH2OCH2)2CH2S-µ) (10b). The same procedure was
followed as for 10a , but 4‚[Et3NH]2 (Z ) CH2(CH2OCH2)2CH2)
was utilized. From the main red band, 0.118 g (13%) of 10b
was obtained as a red oil. Anal. Calcd for C24H22Fe4N2O12S4:
C, 31.54; H, 2.43; N, 3.06. Found: C, 31.70; H, 2.22; N, 3.25.
IR (KBr disk): νCtO 2063 (s), 2017 (vs), 1944 (vs); νC-O-C 1093
1
(m); νCdS 1025 (m) cm-1. H NMR (200 MHz, CDCl3): 1.35-
2.12 (m, 4H, CH2CH2CH2CH2), 2.24-2.80 (m, 4H, 2CH2S),
2.75-3.18 (m, 4H, 2CH2N), 3.71 (br.s, 8H, 4CH2O), 6.62 (s,
2H, 2HN) ppm.
P r ep a r a tion of [(µ-σ,π-P h CHdCP h )F e2(CO)6]2[µ-SCH2-
(CH2OCH2)2CH2S-µ] (11a ). To the above-prepared solution
of 4‚[Et3NH]2 (Z ) CH2(CH2OCH2)2CH2) was added 0.356 g
(2.0 mmol) of PhCtCPh. The mixture was refluxed for 45 min.
Solvent was removed under reduced pressure. The residue was
subjected to TLC separation using acetone/petroleum ether
(1/10 v/v) as eluent. From the main red band, 0.200 g (18%) of
11a was obtained as a red solid, mp 67-69 °C. Anal. Calcd
for C46H32Fe4O14S2: C, 50.40; H, 2.94. Found: C, 50.08; H, 3.13.
P r ep a r a tion of [F e2(CO)6]2[(µ-SCH2(CH2OCH2)3CH2S-
µ)]2 (8b). The same procedure was followed as for 8a , but 4‚
[Et3NH]2 (Z ) CH2(CH2OCH2)3CH2) was employed. From the
main red band, 0.148 g (15%) of 8b was obtained as a red solid,
mp 148 °C dec. Anal. Calcd for C28H32Fe4O18S4: C, 33.36; H,
3.20. Found: C, 33.30; H, 3.15. IR (KBr disk): νCtO 2068 (s),
1
2031 (vs), 1994 (vs), 1975 (s); νC-O-C 1127 (s) cm-1. H NMR

Double-Butterfly Fe/ S Cluster Complexes
Organometallics, Vol. 23, No. 4, 2004 831
Ta ble 5. Cr ysta l Da ta a n d Str u ctu r a l Refin em en t Deta ils for 5a , 7a , 8a , a n d 12a
5a
22H18Fe4O12S2
7a
8a
12a
mol formula
mol wt
C
C
18H12Fe4O14S4
C
24H24Fe4O16S4
C
32H22Fe4O12S2
761.8
803.92
920.07
886.02
temp/K
cryst syst
space group
a/ Å
b/Å
c/Å
293(2)
triclinic
P1h
293(2)
triclinic
P1h
293(2)
triclinic
P1h
293(2)
triclinic
P1h
7.949(4)
8.814(4)
11.157(5)
98.568(8)
98.011(8)
110.770(8)
706.9(6)
1
9.301(6)
11.760(8)
14.532(10)
103.889(11)
97.842(11)
104.773(10)
1458.5(17)
2
8.224(3)
9.766(3)
11.153(4)
88.962(6)
81.064(6)
88.230(6)
884.4(5)
1
7.689(2)
13.441(4)
19.125(6)
75.116(5)
87.337(5)
74.286(6)
1838.3(9)
2
R/deg
â/deg
γ/deg
V/ Å3
Z
Dc/g cm-3
abs coeff/mm-1
F(000)
1.790
2.218
382
1.831
2.298
800
1.728
1.911
464
1.601
1.719
892
limiting indices
-7 e h e 9
-10 e k e 11
-10 e l e 13
ω-2θ
-11 e h e 10
-9 e k e 13
-17 e l e 10
ω-2θ
-10 e h e 10
-12 e k e 6
-13 e l e 13
ω-2θ
-9 e h e 8
-11 e k e 15
-18 e l e 22
ω-2θ
scan type
no. of rflns
3350
7291
5103
7198
no. of indep rflns
2643
5041
3574
6370
Rint
0.0243
0.0204
0.0331
0.0324
2θmax/deg
52.88
2643/0/181
0.0392
50.00
5041/304/399
0.0434
52.86
3574/0/217
0.0504
50.06
6370/0/451
0.0516
no. of data/restraints/params
R
Rw
0.0706
0.1437
0.1161
0.1025
goodness of fit
0.931
0.501 and -0.323
1.087
0.816 and -0.783
1.065
0.515 and -0.411
1.014
0.381 and -0.320
largest diff peak and hole/e Å-3
IR (KBr disk): νCtO 2066 (s), 2036 (vs), 1990 (vs); νC-O-C 1125
P r ep a r a tion of [(µ-σ,π-P h CHdCH)F e2(CO)6]2[µ-SCH2-
(CH2OCH2)3CH2S-µ] (12c). The same procedure was followed
as for 12a , but 4‚[Et3NH]2 (Z ) CH2(CH2OCH2)3CH2) was
utilized. From the main red band, 0.444 g (45%) of 12c was
1
(m); νCdC 1001 (w) cm-1. H NMR (200 MHz, CDCl3): 2.63 (s,
4H, 2CH2S), 3.66-3.77 (m, 10H, 4CH2O, 2PhCH), 6.69-7.24
(m, 20H, 4C6H5) ppm.
P r ep a r a tion of [(µ-σ,π-P h CHdCP h )F e2(CO)6]2[µ-SCH2-
(CH2OCH2)3CH2S-µ] (11b). The same procedure was followed
as for 11a , but 4‚[Et3NH]2 (Z ) CH2(CH2OCH2)3CH2) was used.
From the main red band, 0.182 g (16%) of 11b was obtained
as a red solid, mp 54-55 °C. Anal. Calcd for C48H36Fe4O15S2:
C, 50.56; H, 3.18. Found: C, 50.54; H, 3.38. IR (KBr disk):
νCtO 2064 (s), 2033 (vs), 1990 (vs); νC-O-C 1116 (m); νCdC 992
obtained as a red solid, mp 135 °C dec. Anal. Calcd for C36H30-
Fe4O15S2: C, 43.67; H, 3.05. Found: C, 43.60; H, 3.06. IR (KBr
disk): νCtO 2068 (vs), 2036 (vs), 1988 (vs); νCdC 1596 (w); νC-O-C
1124 (s) cm-1. 1H NMR (200 MHz, CDCl3): 2.57 (s, 4H, 2CH2S),
3.69 (s, 12H, 6CH2O), 4.32 (d, J ) 13.8 Hz, 2H, 2 endo-PhCH),
7.24 (s, 10H, 2C6H5), 8.44 (d, J ) 13.8 Hz, 2H, 2 exo-FeCH)
ppm.
(w) cm-1 1H NMR (200 MHz, CDCl3): 2.62 (s, 4H, 2CH2S),
.
X-r a y Str u ctu r e Deter m in a tion s of 5a , 7a , 8a , a n d 12a .
Single crystals of 5a , 7a , 8a , and 12a suitable for X-ray
diffraction analyses were grown by slow evaporation of their
CH2Cl2/petroleum ether solutions at -20 °C for 7a and at
about 4 °C for 5a , 8a , and 12a . Each crystal was mounted on
a Bruker SMART 1000 automated diffractometer with a
graphite monochromator with Mo KR radiation (λ ) 0.710 73
Å). The structures were solved by direct methods and expanded
by Fourier techniques. The final refinements were accom-
plished by the full-matrix least-squares method with aniso-
tropic thermal parameters for non-hydrogen atoms. The
calculations were performed using the SHELXTL-97 program.
Details of the crystal data, data collections, and structure
refinements are summarized in Table 5.
3.64-3.75 (m, 14H, 6CH2O, 2PhCH), 6.69-7.24 (m, 20H,
4C6H5) ppm.
P r epar ation of [(µ-σ,π-P h CHdCH)Fe2(CO)6]2(µ-S(CH2)4S-
µ) (12a ). To the above-prepared solution of 4‚[Et3NH]2 (Z )
(CH2)4) was added 0.408 g (4.0 mmol) of PhCtCH. The mixture
was refluxed for 1 h and stirred at room temperature for 3 h.
Solvent was removed under reduced pressure. The residue was
subjected to TLC separation using CH2Cl2/petroleum ether
(1/1 v/v) as eluent. From the main red band, 0.450 g (51%)
of 12a was obtained as a red solid, mp 167 °C dec. Anal.
Calcd for C32H22Fe4O12S2: C, 43.38; H, 2.50. Found: C, 43.42;
H, 2.49. IR (KBr disk): νCtO 2068 (vs), 2036 (vs), 1985 (vs);
1
νCdC 1597 (w) cm-1. H NMR (200 MHz, CDCl3): 1.82 (s, 4H,
SCH2CH2CH2CH2S), 2.38 (s, 4H, 2CH2S), 4.35 (d, J ) 13.8 Hz,
2H, 2 endo-PhCH), 7.27 (s, 10H, 2C6H5), 8.46 (d, 2H, J ) 13.8
Hz, 2 exo-FeCH) ppm.
P r ep a r a tion of [(µ-σ,π-P h CHdCH)F e2(CO)6]2[µ-SCH2-
(CH2OCH2)2CH2S-µ] (12b). The same procedure was followed
as for 12a , but 4‚[Et3NH]2 (Z ) CH2(CH2OCH2)2CH2) was used.
From the main red band, 0.374 g (40%) of 12b was obtained
as a red solid, mp 121 °C dec. Anal. Calcd for C34H26Fe4O14S2:
C, 43.16; H, 2.77. Found: C, 42.97; H, 3.01. IR (KBr disk):
Ack n ow led gm en t. We are grateful to the National
Natural Science Foundation of China and the Research
Fund for the Doctoral Program of Higher Education of
China for financial support.
Su p p or tin g In for m a tion Ava ila ble: All crystal data,
atomic coordinates and thermal parameters and bond lengths
and angles for 5a , 7a , 8a , and 12a as CIF files. This material
is available free of charge via the Internet at http://pubs.
acs.org.
ν
CtO 2069 (vs), 2038 (vs), 1988 (vs); νCdC 1597 (w); νC-O-C 1126
1
(s) cm-1. H NMR (200 MHz, CDCl3): 2.57 (t, J ) 6.0 Hz, 4H,
2CH2S), 3.70(s, 4H, 4CH2O), 4.33 (d, J ) 13.8 Hz, 2H, 2 endo-
PhCH), 7.26 (s, 10H, 2C6H5), 8.45 (d, J ) 13.8 Hz, 2H, 2 exo-
FeCH) ppm.
OM034208F