Reactions of butterfly complex anions of the type [(μ-RTe)(μ-CO)Fe2(CO)6]- with electrophiles. A new route to μ4-Se-containing double-butterfly clusters. Crystal structures of (μ-p-MeC6H4Te)(μ-PhCH2SC=S)Fe2 (CO)6

Article abstract of DOI:10.1021/om020132w

The nucleophilic reaction of anions [(μ-RTe)(μ-CO)Fe₂(CO)₆]^- (3) with CS₂ and subsequent treatment with organic halides R′X gave a series of R′S-containing single-butterfly complexes (μ-RTe)(μ-R′SC=S)Fe₂(CO)₆ (4a-d, R = Ph,p-MeC₆H₄; R′ = Me, PhCH₂), whereas 3 reacted with R′NCS followed by treatment with CF₃CO₂H or Mel to afford the R′HN- and R′MeN-containing single-butterfly complexes (μ-RTe)(μ-R′HNC=S)Fe₂(CO)₆ and (μ-RTe)(μ-R′MeNC= S)Fe₂(CO)₆ (5a-d, R = Ph, p-MeC₆H₄; R′ = Ph, PhCH₂). Interestingly, a series of double-butterfly μ₄-Se-containing complexes [(μ-RTe)Fe₂(CO)₆]₂ (μ₄-Se) (6a-e, R = Et, Ph,p-MeC₆H₄, o-MeC₆H₄, p-BrC₆H₄) could be produced via a simple and new synthetic route involving a doubly nucleophilic reaction of anions 3 with an electrophile SeCl₂. New complexes 4a-d, 5a-d, and 6a-e derived from anions 3 have been fully characterized by elemental analysis and IR, ¹H NMR, ¹²⁵Te NMR, and ⁷⁷Se NMR (for 6a-e) spectroscopies. The ¹²⁵Te NMR spectra of the new complexes displayed only one singlet, indicating that they consist of only one isomer, either a(R) or e(R). This has been confirmed by crystal X-ray diffraction analyses of 4d (R = p-MeC₆H₄; R′ = PhCH₂), 6b (R = Ph), and 6e (R = p-BrC₆H₄), in which the R groups are attached to bridged Te atoms by an equatorial type of bond.

Full text of DOI:10.1021/om020132w

2468
Organometallics 2002, 21, 2468-2472
Rea ction s of Bu tter fly Com p lex An ion s of th e Typ e
[(µ-RTe)(µ-CO)F e2(CO)6]- w ith Electr op h iles. A New
Rou te to µ4-Se-Con ta in in g Dou ble-Bu tter fly Clu ster s.
Cr ysta l Str u ctu r es of
(µ-p-MeC6H4Te)(µ-P h CH2SCdS)F e2(CO)6 a n d
[(µ-RTe)F e2(CO)6]2(µ4-Se) (R ) P h , p-Br C6H4)
Li-Cheng Song,*,† Qing-Mei Hu,†,‡ Hong-Tao Fan,† Ming-Yi Tang,†
Zhi-Yong Yang,† and Guo-Liang Lu†
Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry,
Nankai University, Tianjin 300071, China, and Laboratory of Organometallic Chemistry,
Shanghai 200032, China
Received February 19, 2002
The nucleophilic reaction of anions [(µ-RTe)(µ-CO)Fe2(CO)6]- (3) with CS2 and subsequent
treatment with organic halides R′X gave a series of R′S-containing single-butterfly complexes
(µ-RTe)(µ-R′SCdS)Fe2(CO)6 (4a -d , R ) Ph, p-MeC6H4; R′ ) Me, PhCH2), whereas 3 reacted
with R′NCS followed by treatment with CF3CO2H or MeI to afford the R′HN- and R′MeN-
containing single-butterfly complexes (µ-RTe)(µ-R′HNCdS)Fe2(CO)6 and (µ-RTe)(µ-R′MeNCd
S)Fe2(CO)6 (5a -d , R ) Ph, p-MeC6H4; R′ ) Ph, PhCH2). Interestingly, a series of double-
butterfly µ4-Se-containing complexes [(µ-RTe)Fe2(CO)6]2 (µ4-Se) (6a -e, R ) Et, Ph, p-MeC6H4,
o-MeC6H4, p-BrC6H4) could be produced via a simple and new synthetic route involving a
doubly nucleophilic reaction of anions 3 with an electrophile SeCl2. New complexes 4a -d ,
5a -d , and 6a -e derived from anions 3 have been fully characterized by elemental analysis
and IR, 1H NMR, 125Te NMR, and 77Se NMR (for 6a -e) spectroscopies. The 125Te NMR spectra
of the new complexes displayed only one singlet, indicating that they consist of only one
isomer, either a(R) or e(R). This has been confirmed by crystal X-ray diffraction analyses of
4d (R ) p-MeC6H4; R′ ) PhCH2), 6b (R ) Ph), and 6e (R ) p-BrC6H4), in which the R groups
are attached to bridged Te atoms by an equatorial type of bond.
In tr od u ction
ever, anions 3 are much less studied than anions 1 and
2, most likely due to anions 3 being prepared much later
and with more complicated chemistry.7 To further
develop the chemistry of anions 3, we recently initiated
a study on reactivities of anions 3 toward electrophiles
CS2/R′X, R′NCS/CF3CO2H, R′NCS/MeI, and SeCl2. In-
terestingly, while anions 3 reacted with SeCl2 to give a
novel type of double-butterfly Fe4SeTe2 cluster com-
plexes, reactions of 3 with the other electrophiles
mentioned above afforded single-butterfly Fe2Te(CdS)
cluster complexes. Herein we report the synthesis and
spectroscopic (particularly 125Te and 77Se NMR) char-
acterization of these new single- and double-butterfly
cluster compounds, as well as the X-ray crystal diffrac-
tion analyses for clusters (µ-p-MeC6H4Te)(µ-PhCH2SCd
S)Fe2(CO)6 (4d ), [(µ-PhTe)Fe2(CO)6]2(µ4-Se) (6b), and
[(µ-p-BrC6H4Te)Fe2(CO)6]2(µ4-Se) (6e).
The butterfly complex anions containing a µ-CO
ligand [(µ-RE)(µ-CO)Fe2(CO)6]- [1, E ) S; 2, E ) Se; 3,
E ) Te] are very useful versatile synthons in the
synthesis of a great variety of butterfly Fe/E cluster
complexes.1-13 Among the three types of anions, how-
* To whom correspondence should be addressed. Fax: +86-22-
23504853. E-mail: lcsong@public.tpt.tj.cn.
† Nankai University.
‡ Laboratory of Organometallic Chemistry.
(1) Seyferth, D.; Womack, G. B.; Archer, C. M.; Dewan, J . C.
Organometallics 1989, 8, 430.
(2) Seyferth, D.; Womack, G. B.; Archer, C. M.; Fackler, J . P., J r.;
Marler, D. O. Organometallics 1989, 8, 443.
(3) Seyferth, D.; Hoke, J . B.; Womack, G. B. Organometallics 1990,
9, 2662.
(4) Seyferth, D.; Hoke, J . B. Organometallics 1988, 7, 524.
(5) Song, L.-C.; Yan, C.-G.; Hu, Q.-M.; Wang, R.-J .; Mak, T. C. W.;
Huang, X.-Y. Organometallics 1996, 15, 1535.
(6) Song, L.-C.; Yan, C.-G.; Hu, Q.-M.; Wu, B.-M.; Mak, T. C. W.
Organometallics 1997, 16, 632.
Resu lts a n d Discu ssion
(7) Song, L.-C.; Yan, C.-G.; Hu, Q.-M.; Huang, X.-Y. Organometallics
1997, 16, 3769.
Rea ction s of 3 w ith CS2/R′X or R′NCS/CF 3CO2H-
(MeI) a n d Str u ctu r a l Ch a r a cter iza tion of 4a -d
(8) Song, L.-C.; Lu, G.-L.; Hu, Q.-M.; Sun, J . Organometallics 1999,
18, 2700.
(9) Song, L.-C.; Yang, J .; Hu, Q.-M.; Wu, Q.-J . Organometallics 2001,
20, 3293.
(10) Song, L.-C.; Hu, Q.-M.; Fan, H.-T.; Sun, B.-W.; Tang, M.-Y.;
Chen, Y.; Sun, Y.; Sun, C.-X.; Wu, Q.-J . Organometallics 2000, 19, 3909.
(11) Song, L.-C.; Fan, H.-T.; Hu, Q.-M.; Qin, X.-D.; Zhu, W.-F.; Chen,
Y.; Sun, J . Organometallics 1998, 17, 3454.
(12) Song, L.-C.; Lu, G.-L.; Hu, Q.-M.; Yang, J .; Sun, J . J . Orga-
nomet. Chem. 2001, 623, 56.
(13) Song, L.-C.; Lu, G.-L.; Hu, Q.-M.; Fan, H.-T.; Chen, J .-B.; Sun,
J .; Huang, X.-Y. J . Organomet. Chem. 2001, 627, 255.
10.1021/om020132w CCC: $22.00 © 2002 American Chemical Society
Publication on Web 05/16/2002

µ4-Se-Containing Double-Butterfly Clusters
Organometallics, Vol. 21, No. 12, 2002 2469
Sch em e 1
Sch em e 2
F igu r e 1. ORTEP drawing of 4d with atom-labeling
scheme.
by the same type of reactions. This is most likely due
to the increased nucleophilicity of the anions in the
order 3 < 2 < 1 (it should be noted that the yields of
anions 1-3 are generally comparable since the IR
spectra of anions 1-3 showed comparable µ-CO intensi-
ties). While (µ-RTe)2Fe2(CO)6 (R ) Ph,7 p-MeC6H47) are
known, 4a -d and 5a -d are new and have been fully
a n d 5a -d . Up to now, there is still no report in the
literature concerning the reactions of anions 3 with
heterocumulenes CS2 and R′NCS, although the reac-
tions of anions 1 and 2 with such heterocumulenes have
been previously reported.2,14,15 So, it is interesting to
study the reactions of anions 3 with CS2 and R′NCS to
compare the nucleophilicity of these three types of
anions and in order to prepare the corresponding µ-RTe-
containing analogues. We have now found that the
[MgBr]+ salts of anions 3 reacted with carbon disulfide
CS2 followed by treatment of the intermediate [MgBr]+
salts of the S-centered anions (µ-RTe)(µ-SdCS-)Fe2-
(CO)6 (m )2 with organic halides R′X to afford a series of
single-butterfly Fe2Te(CdS) cluster complexes (µ-RTe)-
(µ-R′SCdS)Fe2(CO)6 (4a -d ) (Scheme 1).
1
characterized by elemental analysis, IR, H NMR, and
125Te NMR spectroscopy. For instance, the IR spectra
of 4a -d and 5a -d display three to four absorption
bands in the range 2066-1948 cm-1 for their terminal
carbonyls. In addition, while the 1H NMR spectra of
4a -d and 5a -d exhibit the signals assigned to their R
and R′ groups, the 125Te NMR spectra of 4a -d and
5a -d display a singlet in the region 745-712 ppm
attributed to their bridged Te atoms. It is noteworthy
that products 4a -d and 5a -d might exist theoretically
as two isomers, one with an equatorial R and the other
with an axial R.2,14 However, since the 125Te NMR
spectra of these products show only one signal (a singlet)
for their bridged Te atoms, they should exist as only
one isomer, either a(R) or e(R). Fortunately, this has
been proved by crystal X-ray diffraction analysis of 4d ,
in which the substituent R is attached to the bridged
Te atom by an equatorial type of bond.
The molecular structure of 4d is shown in Figure 1.
Table 1 lists its selected bond lengths and angles. As
can be seen in Figure 1, 4a has two ligands, p-MeC6H4-
Te and PhCH2SCdS, that are bridged to two Fe atoms
of the two Fe(CO)3 structural units to form the iron
carbonyl complex with a single-butterfly Fe2TeCdS
cluster core; in addition, the p-MeC6H4Te ligand is
indeed attached to the bridged Te atom of the butterfly
core by an equatorial type of bond. So, the structure of
4d is totally similar to that of its Se analogue (µ-PhSe)-
(µ-PhCH2SCdS)Fe2(CO)6.14 It is noteworthy that the
carbon C(7) of the S(2)-C(7)-S(1) bridge in 4d pos-
sesses a carbene character16 with an Fe(2)-C(7) bond
equal to 1.955(6) Å. This bond length is very close to
We have also found that reactions of the [MgX]+ salts
of anions 3 with isothiocyanates R′NCS and subsequent
treatment of the intermediate [MgBr]+ salts of the
N-centered anions (µ-RTe)(µ-SdC(R′)N-)Fe2(CO)6 (n )2
with electrophile CF3CO2H or MeI afforded another
series of single-butterfly cluster complexes (µ-RTe)(µ-
R′HNCdS)Fe2(CO)6 (5a -c) and (µ-RTe)(µ-R′MeNCdS)-
Fe2(CO)6 (5d ) (Scheme 2).
It is worth pointing out that the reactions described
above not only gave rise to single-butterfly Fe2Te(Cd
S) clusters 4a -d and 5a -d but also afforded the
corresponding single-butterfly Fe2Te2 clusters (µ-RTe)2-
Fe2(CO)6 (R ) Ph, p-MeC6H4), possibly produced by
decomposition of anions 3 and subsequent dimerization
of the intermediate fragment RTeFe(CO)3.7 In addition,
it is worthy of note that the yields of 4a -d and 5a -d
(11-16%) derived from anions 3 are lower than the
reported yields of their Se analogues (35-47%) derived
from anions 2,14,15 which are in turn lower than their S
analogues (59% to quantitative) derived from anions 12
(14) Song, L.-C.; Yan, C.-G.; Hu, Q.-M.; Wang, R.-J .; Mak, T. C. W.
Organometallics 1995, 14, 5513.
(15) Song, L.-C.; Lu, G.-L.; Hu, Q.-M.; Qin, X.-D.; Sun, C.-X.; Yang,
J . Sun, J . J . Organomet. Chem. 1998, 571, 55.

2470 Organometallics, Vol. 21, No. 12, 2002
Song et al.
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 4d
S(1)-Fe(1)
Te(1)-Fe(1)
C(7)-Fe(2)
C(15)-Te(1)
S(2)-C(8)
2.3053(18)
2.5307(11)
1.955(6)
2.150(6)
1.818(6)
S(1)-C(7)
1.666(6)
2.5474(11)
1.694(6)
2.6665(214
1.527(10)
Fe(2)-Te(1)
S(2)-C(7)
Fe(1)-Fe(2)
C(18)-C(21)
S(1)-Fe(1)-Te(1)
Te(1)-Fe(1)-Fe(2)
Fe(1)-Te(1)-Fe(2)
Te(1)-Fe(2)-Fe(1)
S(1)-C(7)-S(2)
82.14(5) S(1)-Fe(1)-Fe(2)
58.63(3) C(7)-Fe(2)-Te(1)
63.35(3) C(7)-S(1)-Fe(1)
58.02(3) S(2)-C(7)-Fe(2)
75.32(5)
83.76(18)
93.3(2)
122.3(3)
114.6(3)
123.1(4)
S(1)-C(7)-Fe(2)
F igu r e 2. ORTEP drawing of 6b with atom-labeling
scheme.
Sch em e 3
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 6b
Se(1)-Fe(4)
Te(1)-Fe(2)
Te(2)-Fe(3)
Fe(3)-Se(1)
Fe(1)-Fe(2)
2.3370(18)
2.5418(16)
2.5716(17)
2.3551(18)
2.611(2)
Se(1)-Fe(2)
Fe(4)-Te(2)
Se(1)-Fe(1)
Te(1)-Fe(1)
Fe(3)-Fe(4)
2.3458(18)
2.5494(18)
2.3508(17)
2.5565(16)
2.607(2)
Se(1)-Fe(3)-Te(2)
Se(1)-Fe(2)-Te(1)
78.62(5) Te(1)-Fe(1)-Fe(2)
78.62(6) Fe(2)-Te(1)-Fe(1)
58.91(5)
61.62(5)
78.23(5)
56.13(5)
the bond length (1.969 Å) of the Fe-C (carbene) bond
in an iron-carbene-stabilized compound.17 In addition,
in 4d the Fe-Te bond lengths (Fe(1)-Te(1) ) 2.5307-
(11) Å, Fe(2)-Te(1) ) 2.5474(11) Å) and the Fe-Te-
Fe bond angle (Fe(1)-Te(1)-Fe(2) ) 63.35(3)°) are
almost the same as the corresponding ones (2.548(2) Å,
2.551(3) Å, 62.3(1)°, and 62.2(1)°) in butterfly Fe2Te2
complex (µ-MeTe)2 Fe2(CO)6,18 respectively.
Fe(1)-Se(1)-Fe(3) 127.85(6) Se(1)-Fe(1)-Te(1)
Fe(4)-Se(1)-Fe(3)
Fe(1)-Se(1)-Fe(2)
67.51(6) Se(1)-Fe(1)-Fe(2)
67.56(6) Fe(1)-Se(1)-Fe(4) 138.39(7)
containing complexes with a double-butterfly cluster
core Fe4E2(µ4-Se) (E ) S, Se),5 Fe4ESe(µ4-Se) (E ) S,
Se, Te),9 or Fe4SSe(µ4-Se)19 were previously reported.
Products 6a -e are new and have been characterized
by combustion analysis and IR and 1H (77Se, 125Te) NMR
spectroscopy, as well as by X-ray diffraction analysis.
The 77Se NMR spectra of 6a -e show a singlet in the
range 296-239 ppm for their µ4-Se atom, which re-
sembles the corresponding ones of their analogues (µ-
RTe)(µ-R′Se)[Fe2(CO)6]2 (µ4-Se).9 In addition, the 125Te
NMR spectra of 6a -e also display a singlet, which lies
in the range 336-201 ppm (note the remarkably dif-
ferent 125Te NMR values from those of 4a -d and 5a -d
due to different structural types!) for their bridged Te
atoms bonded to R groups with an equatorial type of
bond.5,9 It is worthy of note that the 125Te NMR signal
of 6a (201.37 ppm) appeared at much higher field than
the signals of 6b-e (335.83-290.58 ppm), which is
obviously due to an Et group in 6a being an electron-
donating group and the aromatic R groups in 6b-e
being electron-withdrawing.
To unambiguously confirm the structures of the
double-butterfly complexes 6a -e obtained from the
above new type of reactions, we carried out the crystal
X-ray diffraction analyses for 6b and 6e. Since 6b is
isostructural with 6e, only the ORTEP drawing of the
molecular structure of 6b is shown in Figure 2. Table 2
lists its selected bond lengths and angles. As shown in
Figure 2, 6b consists of two butterfly cores, Fe(1)Fe(2)-
Te(1)Se(1) and Fe(3)Fe(4)Te(2)Se(1), joined to a spiro
type of Se(1) atom; each Fe atom carries three terminal
carbonyls, and both Te atoms are attached to Ph groups
by an equatorial type of bond.5,9 In fact, the double-
butterfly complex 6b is very similar to the double-
butterfly µ4-Se complexes [(µ-EtS)Fe2(CO)6]2(µ4-Se)5 and
(µ-p-MeC6H4Te)(µ-MeSe)[Fe2(CO)6]2(µ4-Se),9 structur-
ally.
Rea ction s of 3 w ith SeCl2 a n d Str u ctu r a l Ch a r -
a ctr iza tion of 6a -e. More interestingly, it has been
found that the [MgBr]+ salts of anions 3 reacted with
SeCl2 from -78 °C to room temperature in THF to give
a new series of µ4-Se-containing double-butterfly cluster
complexes [(µ-RTe)Fe2(CO)6]2(µ4-Se) (6a -e) (Scheme 3).
It should be mentioned that the reactions of the
[MgBr]+ salts of anions 3 with SeCl2, similar to those
with CS2/R′X and R′NCS/CF3CO2H(MeI), also gave the
corresponding single-butterfly complexes (µ-RTe)2Fe2-
(CO)6, generated by decomposition of 3 and subsequent
dimerization of the intermediate fragment RTeFe(CO)3.7
In these complexes, while (µ-RTe)2Fe2(CO)6 (R ) Et,15
Ph,7 P-MeC6H4,7 o-MeC6H47) were previously reported,
(µ-RTe)2Fe2(CO)6 (R ) p-BrC6H4) is new and has been
characterized by elemental analysis and spectroscopy.
In addition, we have proposed a pathway to account for
the formation of double-butterfly complexes 6a -e, on
the basis of similarity with the reactions of anions 3
with other electrophiles containing a leaving group15
(Scheme 4). Apparently, this pathway involves a double
nucleophilic attack of the negatively charged Fe atom
in 3 at the Se atom in SeCl2 to eliminate two Cl- anions
and a double coordination of the lone electron pairs on
the Se atom to the neighboring Fe atoms with concur-
rent loss of two µ-CO ligands.
It is worth pointing out that the reactions of anions
3 with SeCl2 provide a simple and new synthetic route
for µ4-Se-containing double-butterfly cluster complexes,
although the more complicated routes leading to µ4-Se-
(16) Patin, H.; Magnani, G.; Mahe’, C.; Le Marouille, J .-Y.; Southern,
T. G.; Benoit, A.; Grandjean, D. J . Organomet. Chem. 1980, 197, 315.
(17) Schrauzer, G. N.; Rabinowitz, H. N.; Frank, J . A. K.; Paul, I.
C. J . Am. Chem. Soc. 1970, 92, 212.
(18) Bachman, R. E.; Whitmire, K. H. Organometallics 1993, 12,
1988.
(19) Song, L.-C.; Qin, X.-D.; Hu, Q.-M.; Huang, X.-Y. Organometallics
1998, 17, 5437.

µ4-Se-Containing Double-Butterfly Clusters
Organometallics, Vol. 21, No. 12, 2002 2471
Sch em e 4
P r ep a r a tion of (µ-P h Te)(µ-P h CH2SCdS)F e2(CO)6 (4c).
Exp er im en ta l Section
7
Similarly, 0.245 g (35%) of (µ-PhTe)2Fe2(CO)6 and 0.170 g
(13%) of 4c were obtained. 4c: an orange-red solid, mp 121-
122 °C. Anal. Calcd for C20H12Fe2O6S2Te: C, 36.86; H, 1.86.
Found: C, 36.70; H, 1.87. IR (KBr disk): νCtO 2066 (s), 2010
Gen er a l Com m en ts. All reactions were carried out under
an atmosphere of prepurified nitrogen using standard Schlenk
and vacuum-line techniques. Tetrahydrofuran (THF) was
distilled from Na/benzophenone ketyl under nitrogen. Se
powder, Te powder, CH3I, PhCH2Br, PhNCS, PhCH2NCS, CF3-
CO2H, and CS2 were of commercial origin and used without
further purification. Fe3(CO)12,20 Grignard reagents RMgBr,21
1
(vs), 1981 (s), 1958 (vs); νCdS 998 (s) cm-1. H NMR (CDCl3):
4.34 (s, 2H, CH2), 7.01-7.46 (m, 10H, 2C6H5) ppm. 125Te NMR
(CDCl3): 744.76 (s) ppm.
P r ep a r a t ion of (µ-p -MeC6H 4Te)(µ-P h CH 2SCdS)F e2-
(CO)6 (4d ). Similarly, 0.154 g (21%) of (µ-p-MeC6H4Te)2Fe2-
22
and a THF solution of SeCl2 were prepared according to
literature procedures. Preparative TLC was carried out on
glass plates (26 × 20 × 0.25 cm) coated with silica gel H (10-
40 µm). IR spectra were recorded on a Nicolet 170SX FT-IR
or Bruker Vector 22 infrared spectrophotometer. 1H NMR, 77Se
NMR, and125Te NMR spectra were recorded on a Bruker AC-P
200 NMR spectrometer and a Varian Unity-Plus 400 NMR
spectrometer with Ph2Se2 and Ph2Te2 as external standards,
and the chemical shifts are referenced to Me2Se (δ ) 0) and
Me2Te (δ ) 0), respectively. C/H analyses were performed on
an elementar Vario EL analyzer. Melting points were deter-
mined on a Yanaco MP-500 apparatus and were uncorrected.
Gen er a l P r oced u r e for in Situ P r ep a r a tion of In ter -
m ed ia te Sa lts [(µ-RTe)(µ-CO)F e2(CO)6]-[MgBr ]+ (3‚[Mg-
Br ]+: R ) Et, P h , p-MeC6H4, o-MeC6H4, p-Br C6H4). A 100
mL three-necked flask equipped with a magnetic stir-bar, a
rubber septum, and a reflux condenser topped with a N2 inlet
tube was charged with 0.255 g (2.0 mmol) of tellurium powder,
20 mL of THF, and 2.0 mmol of RMgBr (R ) Et, Ph, p-MeC6H4,
o-MeC6H4, p-BrC6H4) in Et2O. The mixture was refluxed for 2
h to give a slightly gray solution of RTeMgBr. Upon cooling
the solution to room temperature, 1.00 g (2.0 mmol) of Fe3-
(CO)12 was added and the mixture was stirred for 1 h to
produce a brown-red solution of the intermediate salts 3‚
[MgBr]+, which was utilized immediately in the following
preparations.
7
(CO)6 and 0.166 g (13%) of 4d were obtained. 4d : an orange-
red solid, mp 130-131 °C. Anal. Calcd for C21H14Fe2O6S2Te:
C, 37.89; H, 2.12. Found: C, 37.86; H, 2.20. IR (KBr disk):
ν
CtO 2058 (vs), 2018 (vs), 1981 (vs), 1958 (vs); νCdS 998 (s) cm-1
. 1H NMR (CDCl3): 2.29 (s, 3H, CH3), 4.34 (s, 2H, CH2), 6.99-
7.45 (m, 9H, C6H5, C6H4) ppm. 125Te NMR (CDCl3): 744.71 (s)
ppm.
P r ep a r a tion of [(µ-P h Te)(µ-P h NHCdS)F e2(CO)6 (5a ).
To the above prepared solution of salt 3‚[MgBr]+ (R ) Ph) was
added 0.24 mL (2.0 mmol) of PhNCS, and the mixture was
stirred at room temperature for 16 h. Then, 0.16 mL (2.1 mmol)
of CF3CO2H was added, and the mixture was continuously
stirred for 2 h. Solvent was removed under reduced pressure.
The residue was subjected to TLC separation using CH2Cl2/
petroleum ether (v/v ) 1:5) as eluent. From the first main band
was obtained 0.241 g (31%) of (µ-PhTe)2Fe2(CO)6.7 The second
main band afforded 0.172 g (14%) of 5a as a red solid, mp 50-
52 °C. Anal. Calcd for C19H11Fe2NO6STe: C, 36.76; H, 1.77;
N, 2.26. Found: C, 36.65; H, 1.83; N, 2.30. IR (KBr disk): νCtO
2057 (s), 2013 (vs), 1970 (s), 1948 (s); νNH 3337 (w) cm-1 1H
.
NMR (CDCl3): 7.34-7.56 (m, 10H, 2C6H5), 8.90 (s, 1H, NH)
ppm. 125Te NMR (CDCl3): 722.02 (s) ppm.
P r ep a r a tion of [(µ-p-MeC6H4Te)(µ-P h NHCdS)F e2(CO)6
(5b). Similarly, 0.230 g (32%) of (µ-p-MeC6H4Te)2Fe2(CO)67 and
0.136 g (11%) of 5b were obtained. 5b: a red solid, mp 124-
126 °C. Anal. Calcd for C20H13Fe2NO6STe: C, 37.84; H, 2.05;
N, 2.21. Found: C, 37.51; H, 2.07; N, 2.25. IR (KBr disk): νCtO
2056 (s), 2014 (vs), 1996 (vs), 1987 (s), 1970 (s), 1948 (s); νNH
3339 (w) cm-1. 1H NMR (CDCl3): 2.31 (s, 3H, CH3), 7.01-7.43
(m, 9H, C6H5, C6H4), 8.90 (s, 1H, NH) ppm. 125Te NMR
(CDCl3): 719.60 (s) ppm.
P r ep a r a tion of (µ-P h Te)(µ-MeSCdS)F e2(CO)6 (4a ). To
the above prepared solution of salt 3‚[MgBr]+ (R ) Ph) was
added 0.15 mL (2.6 mmol) of CS2, and the mixture was stirred
at room temperature for 1 h. Then, 0.15 mL (2.6 mmol) of MeI
was added, and the mixture was continuously stirred for 15
h. Solvent was removed under reduced pressure. The residue
was subjected to TLC separation using CH2Cl2/petroleum ether
(v/v ) 1:20) as eluent. From the first main band was obtained
0.103 g (15%) of (µ-PhTe)2Fe2(CO)6.7 The second main band
afforded 0.185 g (16%) of 4a as a red oil. Anal. Calcd for C14H8-
Fe2O6S2Te: C, 29.21; H, 1.40. Found: C, 29.31; H, 1.41. IR
(KBr disk): νCtO 2058 (vs), 2026 (vs), 1993 (vs), 1970 (vs); νCdS
P r ep a r a tion of [(µ-p-MeC6H4Te)(µ-P h CH2NHCdS)F e2-
(CO)6 (5c). Similarly, 0.268 g (37%) of (µ-p-MeC6H4Te)2Fe2-
7
(CO)6 and 0.146 g (11%) of 5c were obtained. 5c: a red solid,
mp 99-101 °C. Anal. Calcd for C21H15Fe2NO6STe: C, 38.87;
H, 2.31; N, 2.16. Found: C, 38.88; H, 2.37; N, 2.12. IR (KBr
disk): νCtO 2057 (s), 2014 (vs), 1991 (s), 1948 (s); νNH 3352 (w)
cm-1. 1H NMR (CDCl3): 2.30 (s, 3H, CH3), 4.61 (q,q, 2J ) 14.6
Hz, 3J ) 4.2 Hz, 2H, CH2), 6.94-7.42 (m, 9H, C6H5, C6H4),
7.54 (br s, 1H, NH) ppm. 125Te NMR (CDCl3): 712.50 (s) ppm.
P r ep a r a t ion of [(µ-p -MeC6H 4Te)(µ-P h MeNCdS)F e2-
(CO)6 (5d ). To the above prepared solution of salt 3‚[MgBr]+
(R ) p-MeC6H4) was added 0.24 mL (2.0 mmol) of PhNCS, and
the mixture was stirred at room temperature for 1 h. Then,
0.13 mL (2.0 mmol) of MeI was added, and the mixture was
continuously stirred for 15 h. The mixture was subjected to
TLC separation using CH2Cl2/petroleum ether (v/v ) 1:20) as
eluent. From the first main band was obtained 0.240 g (34%)
of (µ-p-MeC6H4Te)2Fe2(CO)6.7 The second main band afforded
0.156 g (12%) of 5d as a red solid, mp 120 °C (dec). Anal. Calcd
for C21H15Fe2NO6STe: C, 38.87; H, 2.31; N, 2.16. Found: C,
38.68; H, 2.34; N, 2.33. IR (KBr disk): νCtO 2122 (m), 2057
1010 (s) cm-1
.
1H NMR (CDCl3): 2.57 (s, 3H, CH3), 7.48 (s,
5H, C6H5) ppm. 125Te NMR (CDCl3): 744.20 (s) ppm.
P r ep a r a t ion of (µ-p -MeC6H 4Te)(µ-MeSCdS)F e2(CO)6
(4b). Similarly, 0.220 g (31%) of (µ-p-MeC6H4Te)2Fe2(CO)67 and
0.174 g (15%) of 4b were obtained. 4b: a red oil. Anal. Calcd
for C15H10Fe2O6S2Te: C, 30.55; H, 1.71. Found: C, 30.70; H,
1.75. IR (KBr disk): νCtO 2042 (vs), 2010 (vs), 1973 (vs); νCdS
1006 (s) cm-1 1H NMR (CDCl3): 2.33 (s, 3H, CH3), 2.56 (s,
.
3H, CH3SCdS), 7.48 (s, 4H, C6H4) ppm. 125Te NMR (CDCl3):
742.00 (s) ppm.
(20) King, R. B. Organometallic Syntheses; Transition-Metal Com-
pounds; Academic Press: New York, 1965; Vol. 1, P. 95.
(21) Gilman, H.; Zoellner, E. A.; Dickey, J . B. J . Am. Chem. Soc.
1929, 51, 1576.
(22) Maaninen, A.; Chivers, T.; Parvez, M.; Pietika¨inen, J .; Laitinen,
R. S. Inorg. Chem. 1999, 38, 4093.

2472 Organometallics, Vol. 21, No. 12, 2002
Ta ble 3. Cr ysta l Da ta a n d Str u ctu r a l Refin em en ts Deta ils for 4d , 6b, a n d 6e
Song et al.
4d
6b
6e
mol formula
mol wt
cryst syst
space group
a/ Å
C
21H14Fe2O6S2Te
C24H10Fe4O12SeTe2
1047.88
monoclinic
P2(1)/c
9.041(3)
13.156(5)
27.322(9)
98.392(6)
3215(2)
4
C24H8Br2Fe4O12SeTe2
1205.68
monoclinic
P2(1)/c
19.499(6)
9.537(3)
18.409(6)
91.941(7)
3421.5(19)
4
665.74
monoclinic
P2(1)/c
12.414(3)
8.891(2)
23.421(6)
104.910(4)
2498.0(11)
4
1.770
1296
2.506
293
b/Å
c/Å
â/ deg
V/ Å3
Z
Dc/g cm-3
F(000)
2.165
1968
4.736
298
2.341
2240
6.788
293
abs coeff/mm-1
temp/K
scan type
2θmax/deg
no. of reflns
no. of indep reflns
Rint
ω-2θ
ω-2θ
ω-2θ
50.04
50.06
50.04
10104
4408
0.0493
4408/0/289
13060
5676
0.0675
5676/0/388
13808
6039
0.1072
6039/0/406
no. of data/restraints/
params
R
0.0357
0.0422
0.0508
Rw
0.0662
0.0891
0.1104
goodness of fit
largest diff peak
and hole/e Å-3
1.086
0.590 and -0.595
0.979
0.862 and -1.085
0.967
0.816 and -0.990
1
(s), 2015 (vs), 1987 (vs) cm-1. H NMR (CDCl3): 2.30 (s, 3H,
CH3), 3.34 (s, 3H, NCH3), 7.08-7.58 (m, 9H, C6H5, C6H4) ppm.
125Te NMR (CDCl3): 716.92 (s) ppm.
2.40-2.65 (m. 6H, 2CH3), 6.95-7.55 (m, 8H, 2C6H4) ppm. 77Se
NMR (CDCl3): 270.38 (s) ppm. 125Te NMR (CDCl3): 290.58 (s)
ppm.
P r ep a r a tion of [(µ-EtTe)F e2(CO)6]2(µ4-Se) (6a ). To the
above prepared solution of salt 3‚[MgBr]+ (R ) Et) cooled to
-78 °C by a dry ice/acetone bath was added ca. 1 mmol of SeCl2
in 5 mL of THF, which was prepared from Se powder and SO2-
Cl2 according to literature.22 The mixture was stirred for 30
min at this temperature. After the bath was removed, the
mixture was naturally warmed to room temperature and then
was continuously stirred for 12 h. The mixture was subjected
to TLC separation using petroleum ether as eluent. From the
first main red band was obtained 0.040 g (7%) of (µ-EtTe)2Fe2-
(CO)6.15 The second main dark red band afforded 0.160 g (17%)
of 6a as a dark red solid, mp 110 °C (dec). Anal. Calcd for
P r ep a r a tion of [(µ-p-Br C6H4Te)F e2(CO)6]2(µ4-Se) (6e).
Similarly, 0.070 g (8%) of (µ-p-BrC6H4Te)2Fe2(CO)6 and 0.270
g (22%) of 6e were obtained. (µ-p-BrC6H4Te)2Fe2(CO)6: a red
solid, mp 120-125 °C. Anal. Calcd for C18H8Br2Fe2O6Te2: C,
25.52; H, 0.95. Found: C, 25.46; H, 0.93. IR (KBr disk): νCtO
2058 (vs), 2010 (vs), 1985 (vs), 1962 (vs) cm-1 1H NMR
.
(CDCl3): 7.10 (s, 8H, 2C6H4) ppm. 6e: a dark red solid, mp
>300 °C. Anal. Calcd for C24H8Br2Fe4O12SeTe2: C, 23.91; H,
0.67. Found: C, 23.91; H, 0.69. IR (KBr disk): νCtO 2074 (s),
2018 (vs), 1985 (vs), 1966 (s) cm-1. 1H NMR (acetone-d6): 7.54
(q, AA′BB′, J ) 8.0 Hz, 8H, 2C6H4) ppm. 77Se NMR (CDCl3):
239.42 (s) ppm. 125Te NMR (CDCl3): 330.83 (s) ppm.
C
16H10Fe4O12SeTe2: C, 20.19; H, 1.06. Found: C, 19.86; H,
X-r a y Str u ctu r e Deter m in a tion s of 4d , 6b, a n d 6e.
Single-crystals of 4d , 6b, and 6e suitable for X-ray diffraction
analyses were grown by slow evaporation of their CH2Cl2/
hexane solutions at about 4 °C. Each crystal was mounted on
a Bruker SMART 1000 automated diffractometer with a
graphite monochromator with Mo KR radiation (λ ) 0.71073
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. Hydrogen
atoms were located by using the geometric method. The
calculations were performed using the SHELXTL-97 program.
Details of the crystal data, data collections, and structure
refinements are summarized in Table 3.
1.11. IR (KBr disk): νCtO 2082 (s), 2026 (vs), 1997 (vs), 1981
1
(vs), 1966 (vs)cm-1. H NMR (CDCl3): 1.53 (br s, 6H, 2CH3),
2.78 (br s, 4H, 2CH2) ppm. 77Se NMR (CDCl3): 295.56 (s) ppm.
125Te NMR (CDCl3): 201.37 (s) ppm.
P r ep a r a tion of [(µ-P h Te)F e2(CO)6]2(µ4-Se) (6b). Simi-
7
larly, 0.180 g (26%) of (µ-PhTe)2Fe2(CO)6 and 0.160 g (15%)
of 6b were obtained. 6b: a dark red solid, mp 190-192 °C
(dec). Anal. Calcd for C24H10Fe4O12SeTe2: C, 27.50; H, 0.96.
Found: C, 27.13; H, 1.00. IR (KBr disk): νCtO 2082 (s), 2050
(vs), 2018 (vs), 1985 (vs), 1966 (vs) cm-1 1H NMR (acetone-
.
d6): 7.17-7.66 (m, 10H, 2C6H5) ppm. 77Se NMR (CDCl3):
252.52 (s) ppm. 125Te NMR (CDCl3): 335.83(s) ppm.
P r ep a r a tion of [(µ-p-MeC6H4Te)F e2(CO)6]2(µ4-Se) (6c).
7
Similarly, 0.160 g (22%) of (µ-p-MeC6H4Te)2Fe2(CO)6 and
0.120 g (11%) of 6c were obtained. 6c: a dark red solid, mp
150 °C (dec). Anal. Calcd for C26H14Fe4O12SeTe2: C, 29.02; H,
1.31. Found: C, 28.78; H, 1.29. IR (KBr disk): νCtO 2082 (s),
2026 (vs), 1997 (s), 1981 (vs), 1962 (s) cm-1. 1H NMR (CDCl3):
2.32 (s. 6H, 2CH3) 6.90-7.30 (m, 8H, 2C6H4) ppm. 77Se NMR
(CDCl3): 258.44 (s) ppm. 125Te NMR (CDCl3): 332.40 (s) ppm.
P r ep a r a tion of [(µ-o-MeC6H4Te)F e2(CO)6]2(µ4-Se) (6d ).
Similarly, 0.100 g (14%) of (µ-o-MeC6H4Te)2Fe2(CO)67 and 0.288
g (27%) of 6d were obtained. 6d : a dark red solid, mp 108 °C
(dec). Anal. Calcd for C26H14Fe4O12SeTe2: C, 29.02; H, 1.31.
Found: C, 28.63; H, 1.31. IR (KBr disk): νCtO 2050 (vs), 2018
Ack n ow led gm en t. We are grateful to the National
Natural Science Foundation of China for financial
support.
Su p p or tin g In for m a tion Ava ila ble: Full tables of crystal
data, atomic coordinates and thermal parameters, and bond
lengths and angles for 4d , 6b, and 6e. This material is
available free of charge via the Internet at http://pubs. acs.org.
(vs), 1993 (vs), 1977 (vs), 1958 (vs) cm-1
.
1H NMR (CDCl3):
OM020132W