Formation of novel tellurium-containing anions[(μ-RTe)(μ-CO)Fe 2(CO)6-] and synthesis of Fe/Te clusters (μ-RTe)(μ-σ,π-PhC=CH2)Fe2(CO)6, (μ-RTe)2Fe2(CO)6, and [(μ-RTe)Fe2 (CO)6]2(μ-Te-Te-Te-μ).

Article abstract of DOI:10.1021/om970272j

A series of lithium salts of the anions [(M-RTe)(μ-CO)Fe₂(CO)₆^-] (R = n-Bu, Ph, o-MeC₆H₄, p-MeC₆H₄) were prepared by reaction of organolithium reagents with elemental tellurium, followed by treatment of the intermediates RTeLi with Fe₃(CO)₁₂ in THF at room temperature. Further treatment of the lithium salt [(μ-RTe)(μ-CO)Fe₂(CO)₆^-]Li⁺ (R = n-Bu) in situ with PhC≡CH at room temperature yielded Fe₂Te₂ and Fe₂Te clusters (μ-n-BuTe)₂Fe₂-(CO)₆ (1) and (μ-n-BuTe)(μ-σ,π-PhC=CH₂)Fe₂(CO) ₆ (2), whereas the lithium salts [(μ-RTe)-(μ-CO)Fe₂(CO)₆^-]Li⁺ (R = n-Bu, Ph, o-MeC₆H₄, p-MeC₆H₄) were treated in situ with acid chlorides, such as MeC(O)Cl and p-MeC₆H₄SO₂Cl, to afford Fe₂Te₂ clusters (μ-RTe)₂Fe₂(CO)₆ (R = n-Bu (1), Ph (4), o-MeC₆H₄ (6), p-MeC₆H₄ (8) and double Fe₂Te₂ clusters [(μ-RTe)Fe₂-(CO)₆]₂(μ-Te-Te-μ) (R = n-Bu (3), Ph (5), o-MeC₆H₄ (7), p-MeC₆H₄ (9)). In addition, the new single clusters, except 1, were separated into ae and ee (where a = axial and e = equatorial) isomers and characterized individually, whereas the new double clusters were isolated and characterized mostly as isomer mixtures. Possible pathways for the formation of such clusters have been proposed, and the crystal structure of the double cluster 5 was determined by X-ray diffraction analysis.

Full text of DOI:10.1021/om970272j

Organometallics 1997, 16, 3769-3774
3769
F or m a tion of Novel Tellu r iu m -Con ta in in g An ion s
-
[(µ-RTe)(µ-CO)F e2(CO)6 ] a n d Syn th esis of F e/Te Clu ster s
(µ-RTe)(µ-σ,π-P h CdCH2)F e2(CO)6, (µ-RTe)2F e2(CO)6, a n d
[(µ-RTe)F e2(CO)6]2(µ-Te-Te-µ). X-r a y Cr ysta l Str u ctu r e
of [(µ-P h Te)F e2(CO)6]2(µ-Te-Te-µ)
Li-Cheng Song,*,† Chao-Guo Yan,† Qing-Mei Hu,† and Xiao-Ying Huang‡
Department of Chemistry, Nankai University, Tianjin 300071, China, and
State Key Laboratory of Structural Chemistry, Fuzhou 350002, China
Received March 31, 1997X
-
A series of lithium salts of the anions [(µ-RTe)(µ-CO)Fe2(CO)6 ] (R ) n-Bu, Ph, o-MeC6H4,
p-MeC6H4) were prepared by reaction of organolithium reagents with elemental tellurium,
followed by treatment of the intermediates RTeLi with Fe3(CO)12 in THF at room
temperature. Further treatment of the lithium salt [(µ-RTe)(µ-CO)Fe2(CO)6 ]Li+ (R ) n-Bu)
-
in situ with PhCtCH at room temperature yielded Fe2Te2 and Fe2Te clusters (µ-n-BuTe)2Fe2-
(CO)6 (1) and (µ-n-BuTe)(µ-σ,π-PhCdCH2)Fe2(CO)6 (2), whereas the lithium salts [(µ-RTe)-
(µ-CO)Fe2(CO)6 ]Li+ (R ) n-Bu, Ph, o-MeC6H4, p-MeC6H4) were treated in situ with acid
-
chlorides, such as MeC(O)Cl and p-MeC6H4SO2Cl, to afford Fe2Te2 clusters (µ-RTe)2Fe2(CO)6
(R ) n-Bu (1), Ph (4), o-MeC6H4 (6), p-MeC6H4 (8) and double Fe2Te2 clusters [(µ-RTe)Fe2-
(CO)6]2(µ-Te-Te-µ) (R ) n-Bu (3), Ph (5), o-MeC6H4 (7), p-MeC6H4 (9)). In addition, the
new single clusters, except 1, were separated into ae and ee (where a ) axial and e )
equatorial) isomers and characterized individually, whereas the new double clusters were
isolated and characterized mostly as isomer mixtures. Possible pathways for the formation
of such clusters have been proposed, and the crystal structure of the double cluster 5 was
determined by X-ray diffraction analysis.
In tr od u ction
same group with S and Se in the periodic table. One
might ask if the Te analogs could be made by simi-
lar procedures and if they would have chemical be-
havior similar to that of [(µ-RE)(µ-CO)Fe2(CO)6-] (E )
S, Se). In this paper we will answer some of these
questions by describing the preparation of the anions
[(µ-RTe)(µ-CO)Fe2(CO)6-], as well as their reactions with
some electrophiles to give a series of Fe/Te cluster
complexes.
Since the first preparations of the anions [(µ-RS)(µ-
- 1
CO)Fe2(CO)6
]
and [(µ-RSe)(µ-CO)Fe2(CO)6-],2 the
chemical reactivities concerning such types of anions
have been intensively studied and widely used in the
synthesis of novel Fe/S and Fe/Se cluster complexes.1-4
However, up to now, tellurium analogs of those anions,
i.e., [(µ-RTe)(µ-CO)Fe2(CO)6-], have not been reported
in the literature, although the element Te is in the
Resu lts a n d Discu ssion
† Nankai University.
‡ State Key Laboratory of Structural Chemistry.
Tellurols, RTeH, in contrast to REH (E ) S, Se), are
not commercially available and their preparation is
more difficult. However, their derived salts, RTeM (M
) Li, MgX), can be readily prepared by the reaction of
elemental Te with organolithium or Grignard reagents.5
Although the anions [(µ-RE)(µ-CO)Fe2(CO)6-] (E ) S,
Se) can be prepared by both the Fe3(CO)12/Et3N/REH
(E ) S, Se)1,2 and Fe3(CO)12/REM (M ) Li, MgX)
methods,3b,4d,h the practical preparation of their Te
analogs, [(µ-RTe)(µ-CO)Fe2(CO)6-], is restricted to the
latter method. Tellurol salts, RTeLi (R ) n-Bu, Ph,
o-MeC6H4, p-MeC6H4), prepared from the corresponding
lithium reagents and tellurium powder in THF, react
with Fe3(CO)12 at room temperature to give the corre-
sponding lithium salts of the expected anions [(µ-RTe)-
(µ-CO)Fe2(CO)6-] (R ) n-Bu, Ph, o-MeC6H4, p-MeC6H4,
the salts are denoted as ZLi) (eq 1).
X Abstract published in Advance ACS Abstracts, J uly 15, 1997.
(1) Seyferth, D.; Womack, G. B.; Dewan, J . C. Organometallics 1985,
4, 398.
(2) Seyferth, D.; Womack, G. B.; Archer, C. M.; Dewan, J . C.
Organometallics 1989, 8, 430.
(3) (a) Seyferth, D.; Archer, C. M. Organometallics 1986, 5, 2572.
(b) Seyferth, D.; Hoke, J . B.; Dewan, J . C. Organometallics 1987, 6,
895. (c) Seyferth, D.; Wood, T. G. Organometallics 1988, 7, 714. (d)
Wisian-Neilson, P.; Onan, K. D.; Seyferth, D. Organometallics 1988,
7, 917. (e) Seyferth, D.; Womack, G. B.; Archer, C. M.; Fackler, J . P.,
J r.; Maler, D. O. Organometallics 1989, 8, 443. (f) Seyferth, D.;
Ruschke, D. P.; Davis, W. M.; Cowie, M.; Hunter, A. D. Organometallics
1989, 8, 836. (g) Seyferth, D.; Hoke, J . B.; Womack, G. B. Organome-
tallics 1990, 9, 2662. (h) Seyferth, D.; Archer, C. M.; Ruschke, D. P.;
Cowie, M.; Hilts, R. W. Organometallics 1991, 10, 3363. (i) Seyferth,
D.; Anderson, L. L.; Villafa˜ne, F.; Cowie, M.; Hilts, R. W. Organome-
tallics 1992, 11, 3262.
(4) (a) Song, L.-C.; Liu, J .-T.; Wang, J .-T. Acta Chim. Sin. 1990, 48,
110. (b) Song, L.-C.; Wang, R.-J .; Liu, J .-T.; Wang, H.-G.; Wang, J .-T.
Acta Chim. Sin. 1990, 48, 1141. (c) Song, L.-C.; Hu, Q.-M. J .
Organomet. Chem. 1991, 414, 219. (d) Song, L.-C.; Hu, Q.-M.; He, J .-
L.; Wang, R.-J .; Wang, H.-G. Heteroat. Chem. 1992, 3, 465. (e) Song,
L.-C.; Hu, Q.-M.; Cao, X.-C. Chem. J . Chinese Univ. 1994, 15, 1331. (f)
Song, L.-C.; Yan, C.-G.; Hu, Q.-M.; Wang, R.-J .; Wang, H.-G. Acta
Chim. Sin. 1995, 53, 402. (g) Song, L.-C.; Yan, C.-G.; Hu, Q.-M.; Wang,
R.-J .; Mak, T. C. W. Organometallics 1995, 14, 5513. (h) Song, L.-C.;
Yan, C.-G.; Hu, Q.-M.; Wang, R.-J .; Mak, T. C. W.; Huang, X.-Y.
Organometallics 1996, 15, 1535.
(5) (a) Haller, W. S.; Irgolic, K. J . J . Organomet. Chem. 1972, 38,
97. (b) Seebach, D.; Beck, A. R. Chem. Ber. 1975, 108, 314. (c)
Henriksen, L. In The Chemistry of Organic Selenium and Tellurium
Compounds; Patai, S., Ed.; Wiley: New York, 1987; Vol. 2, p 393.
S0276-7333(97)00272-0 CCC: $14.00 © 1997 American Chemical Society

3770 Organometallics, Vol. 16, No. 17, 1997
Song et al.
â-carbon implies that anion Z (R ) n-Bu), as an iron-
centered nucleophile, attacked at the R-carbon atom of
PhCtCH to give a â-carbanion intermediate. This
intermediate would then displace the bridging CO by
coordination of its CdC double bond, followed by
abstraction of one proton obviously from PhCtCH to
give product 2. This proposed pathway for the forma-
tion of 2 is shown in Scheme 1 and is similar to that
proposed for reactions of [(µ-RE)(µ-CO)Fe2(CO)6-] with
acetylenes.3g,4f
In order to further compare the chemical behavior of
anions Z with that of [(µ-RE)(µ-CO)Fe2(CO)6-] (E ) S,
Se), the reaction of ZLi (R ) n-Bu) with MeC(O)Cl was
carried out. A single cluster 1, as a mixture of two
isomers 1a e and 1ee, and a double Fe2Te2 cluster [(µ-
n-BuTe)Fe2(CO)6]2(µ-Te-Te-µ) (3) were formed in this
reaction (eq 3).
It is noteworthy that during the course of the reac-
tions a gas (CO) was continuously evolved until no
green Fe3(CO)12 remained. This observation also was
made in the case of reactions of RELi (E ) S, Se) with
Fe3(CO)12.3b The formation of ZLi was further demon-
strated by IR spectroscopy. For example, the IR spec-
trum of the anion Z (R ) Ph), i.e., [(µ-PhTe)(µ-CO)-
Fe2(CO)6-], in THF showed a µ-CO absorption band
at 1745 cm-1, which is very close to those of its ana-
- 1
logs [(µ-EtS)(µ-CO)Fe2(CO)6
]
and [(µ-PhSe)(µ-CO)-
- 4f
Fe2(CO)6
]
at 1743 and 1740 cm-1, respectively.
The lithium salts ZLi, similar to the salts of the anions
[(µ-RE)(µ-CO)Fe2(CO)6-] (E ) S, Se), are quite air
sensitive and thermally unstable, so it is best to carry
out their reactions in situ. When an electrophile phen-
ylacetylene was added to a THF solution of ZLi (R )
n-Bu) and the mixture was stirred at room tempera-
ture for 4 h, TLC showed two major products were
formed, and from the reaction mixture a single Fe2Te2
cluster 1 and a single Fe2Te cluster 2 could be isolated
(eq 2).
It was reported previously that the reaction of [(µ-
RS)(µ-CO)Fe2(CO)6-] with MeC(O)Cl produced (µ-RS)2-
Fe2(CO)6 and µ-acyl derivatives,4b whereas the reaction
of [(µ-RSe)(µ-CO)Fe2(CO)6-] with MeC(O)Cl gave only
(µ-RSe)2Fe2(CO)6 as isolable products,4f and in neither
case were the analogs of cluster 3, namely [(µ-RE)Fe2-
(CO)6]2 (µ-E-E-µ) (E ) S, Se), formed. In order to know
if the formation of such double clusters [(µ-RTe)Fe2-
(CO)6]2(µ-Te-Te-µ) is general, we carried out further the
reactions of the lithium salts ZLi (R ) Ph, o-MeC6H4,
p-MeC6H4) with MeC(O)Cl. The results showed that the
same type of double clusters 5, 7, and 9 were obtained
along with single clusters 4, 6, and 8 (Scheme 2).
In contrast to the single cluster 1, the single clusters
4, 6, and 8 can be separated into ae and ee isomers by
TLC (although 4 was previously prepared by another
route,6 it was not separated into such two isomers).
These isomers have been individually characterized by
1
elemental analysis, IR and H NMR spectroscopies, and
The formation of new clusters 1 and 2 is not surpris-
ing since the corresponding reactions with [(µ-RE)(µ-
CO)Fe2(CO)6-]Et3NH+ (E ) S, Se) gave the same types
of products.3g,4f However, it should be noted (i) that the
1
MS. In the H NMR spectra of isomers 4a e and 4ee,
the phenyl groups all showed one complicated multiplet
with a different shape and δ value. For isomers 6a e
and 6ee, the 1H NMR spectra of the eight protons of
the two ortho-substituted benzene rings also showed a
complicated multiplet with a different shape and δ
value. In addition, the 1H NMR spectrum of 6a e
showed one singlet at 2.50 ppm assigned to its two
methyl groups on the substituted benzene rings bound
to Te atoms by an equatorial bond and an axial bond,
respectively, whereas that of 6ee exhibited one singlet
at 2.55 ppm attributed to its two methyl groups on the
substituted benzene rings bound to Te atoms by an
equatorial bond. That only one resonance was observed
1
very complicated H NMR patterns of the butyl groups
indicated that product 1 exists as a mixture of two
isomers 1a e and 1ee (where a ) axial and e ) equator-
rial). For the former two alkyl groups are attached to
the two Te atoms, respectively, by an axial and equator-
ial bond, whereas for the latter both are attached to the
two Te atoms by equatorial bonds. (ii) For 2, the n-butyl
group is most likely attached to the Te atom by an
equatorial bond and the two protons on the CdC double
bond are both located on the â-carbon atom, since the
1H NMR spectrum of the R-CH2 of the n-butyl group
showed one triplet at 2.87 ppm and the two protons
exhibited two doublets at 2.07 and 3.55 ppm with J )
3.6 Hz, respectively. That there are two protons on the
(6) (a) Kostiner, E.; Reddy, M. L. N.; Urch, D. S.; Massey, A. G. J .
Organomet. Chem. 1968, 15, 383. (b) Schermer, E. D.; Baddley, W. H.
J . Organomet. Chem. 1971, 30, 67.

Formation of Novel Te-Containing Anions
Organometallics, Vol. 16, No. 17, 1997 3771
Sch em e 1
Sch em e 2
for the two methyl substituents in isomer 6a e might
be attributed to the fact that they are more distant from
the axially and equatorially bonded benzene rings. For
isomer 8a e, the eight protons of the two substituted
benzene rings showed two sets of AA′BB′ quartets
between 6.96 and 7.28 ppm whereas the six protons of
the two para-substituted methyl groups exhibited one
singlet at 2.34 ppm. Apparently, this is consistent with
the two p-MeC6H4 groups being attached to two Te
atoms via an axial bond and an equatorial bond. For
isomer 8ee, those protons of the substituted benzene
rings showed an AA′BB′ quartet between 7.01 and 7.41
ppm whereas the protons of the para-substituted methyl
groups exhibited one singlet at 2.36 ppm. This is
consistent with the two p-MeC6H4 groups being attached
to Te atoms via an equatorial type of bond. In addition,
since the yield ratios are 4a e/4ee ) 3:1, 6a e/6ee ) 8:1,
8a e/8ee ) 3:1, the ae isomers should be more stable
than ee isomers. This was also commonly observed for
isomers of (µ-RE)2Fe2(CO)6 (E ) S, Se) and related
complexes.4,7
proposed above. However, for 5 and 7, the elemental
analysis and H NMR spectra show them to contain one
1
molecule of pentane, which has been further confirmed
for 5 by an X-ray crystal diffraction analysis (vide infra).
The pentane molecules which combined with 5 and 7,
evidently this originated from the petroleum ether used
in the chromatographic separation and recrystallization,
had not been completely removed during vacuum dry-
ing. In principle, double clusters 3, 5, 7, and 9 should
have more isomers than single clusters 1, 4, 6, and 8.4g
According to the 1H NMR spectra, we may conclude that
3, 5, and 7 are all isomer mixtures whereas 9 is one
1
single isomer. This is because the H NMR spectra for
1
group R of 3, 5, and 7 are very complicated and the H
NMR spectrum for group R of 9 is simple: one singlet
at 2.50 ppm assigned to the six protons of the two para-
substituted methyl groups and an AA′BB′ quartet
between 7.56 and 8.16 ppm for the eight protons of the
substituted benzene rings. On the basis of the isomer
analysis for its analogs, [(µ-RE)Fe2(CO)6](µ-S-S-µ) (E )
S, Se),4g 9 could exist possibly as one of the three
isomers, namely e(p-MeC6H4) e(p-MeC6H4) with an axial
bond between two bridged Te atoms a(p-MeC6H4) a(p-
MeC6H4), or e(p-MeC6H4) e(p-MeC6H4) with an equato-
rial bond between the two Te atoms, as shown in
Scheme 3.
In the reactions mentioned above, the formation of
single clusters 1, 4, 6, and 8 is not unusual, since the
reactions involving analogs of anions Z, i.e., [(µ-RE)(µ-
CO)Fe2(CO)6-] (E ) S, Se), produced the same type of
single clusters (µ-RE)2Fe2(CO)6 (E ) S, Se).14 Clusters
of the type (µ-RTe)2Fe2(CO)6 might be generated through
decomposition of the anions [(µ-RTe)(µ-CO)Fe2(CO)6-],
followed by dimerization of the intermediate fragments
(µ-RTe)Fe(CO)3. This is because (i) TLC showed that
the appearance of (µ-RTe)2Fe2(CO)6 comes after the
formation of [(µ-RTe)(µ-CO)Fe2(CO)6-], which rules out
the possibility of (µ-RTe)2Fe2(CO)6 being formed directly
The double clusters 3, 5, 7, and 9 [(µ-RTe)Fe2(CO)6]2-
(µ-Te-Te-µ) are the first examples of such organome-
tallic clusters with a ditelluride bridge, although some
dinuclear organometallic molecules with a ditelluride
bridge such as [Cp(Et3P)(CO)Fe]2(µ-Te-Te-µ)8a and
[(Et3P)2(CO)3Mn]2(µ-Te-Te-µ),8b are known. For 3 and
1
9, the elemental analysis data and the IR and H NMR
spectra are in good agreement with the structures
(7) Seyferth, D.; Henderson, R. S.; Song, L.-C. Organometallics 1982,
1, 125.
(8) (a) Steigerwald, M. L. Chem. Mater. 1989, 1, 52. (b) Steigerwald,
M. L.; Rice, C. E. J . Am. Chem. Soc. 1988, 110, 4228.
(9) Seyferth, D.; Kiwan, A. M.; Sinn, E. J . Organomet. Chem. 1985,
281, 111.
(10) Eichhorn, B. W.; Haushalter, R. C.; Merola, J . S. Inorg. Chem.
1990, 29, 728.
(11) Mathur, P.; Reddy, V. D.; Das, K.; Sinha, U. C. J . Organomet.
Chem. 1991, 409, 255.
(12) Bachman, R. E.; Whitmire, K. H. Organometallics 1993, 12,
1988.
(13) Mathur, P.; Reddy, V. D.; Bohra, R. J . Organomet. Chem. 1991,
401, 339.
(14) Schumann, H.; Magerstadt, M.; Pickardt, J . J . Organomet.
Chem. 1982, 240, 407.

3772 Organometallics, Vol. 16, No. 17, 1997
Song et al.
Sch em e 3
Ta ble 1. Selected Bon d Len gth s (Å) a n d Bon d
An gles (d eg) for 5
Te(1)-Fe(2)
Te(1)-Fe(1)
Te(2)-Fe(1)
Te(2)-Fe(2)
Te(2)-Te(3)
Te(3)-Fe(4)
Te(3)-Fe(3)
Te(4)-Fe(3)
Te(4)-Fe(4)
Fe(1)-Fe(2)
Fe(3)-Fe(4)
Te(1)-C(13)
Te(4)-C(19)
Fe(1)-C(2)
Fe(1)-C(1)
Fe(1)-C(3)
2.516(9)
2.53(1)
2.532(8)
2.543(9)
2.826(5)
2.524(8)
2.57(1)
2.528(9)
2.546(9)
2.61(1)
2.61(1)
2.18(4)
2.33(6)
1.75(6)
1.88(7)
1.92(6)
O(4)-C(4)
O(5)-C(5)
O(6)-C(6)
O(7)-C(7)
O(8)-C(8)
O(9)-C(9)
O(10)-C(10)
Fe(2)-C(4)
Fe(2)-C(5)
Fe(3)-C(9)
Fe(3)-C(7)
Fe(3)-C(8)
Fe(4)-C(12)
Fe(4)-C(11)
Fe(4)-C(10)
1.08(6)
1.0(1)
1.15(8)
1.16(7)
1.14(6)
1.21(5)
1.13(5)
1.77(6)
1.8(1)
1.68(5)
1.77(7)
1.78(5)
1.64(6)
1.76(6)
1.77(5)
F igu r e 1. ORTEP view of 5 with atom-labeling scheme.
Fe(2)-Te(1)-Fe(1)
Fe(1)-Te(2)-Fe(2)
Fe(1)-Te(2)-Te(3)
Fe(2)-Te(2)-Te(3)
Fe(4)-Te(3)-Fe(3)
Fe(4)-Te(3)-Te(2)
Fe(3)-Te(3)-Te(2)
Fe(3)-Te(4)-Fe(4)
Te(2)-Fe(1)-Te(1)
Te(2)-Fe(1)-Fe(2)
Te(1)-Fe(1)-Fe(2)
Te(1)-Fe(2)-Te(2)
Te(1)-Fe(2)-Fe(1)
Te(2)-Fe(2)-Fe(1)
Te(4)-Fe(3)-Te(3)
Te(4)-Fe(3)-Fe(4)
Te(3)-Fe(3)-Fe(4)
C(13)-Te(1)-Fe(2)
C(13)-Te(1)-Fe(1)
62.3(3)
C(1)-Fe(1)-Fe(2)
C(3)-Fe(1)-Te(2)
C(3)-Fe(1)-Te(1)
C(3)-Fe(1)-Fe(2)
C(6)-Fe(2)-Te(1)
C(6)-Fe(2)-Te(2)
C(6)-Fe(2)-Fe(1)
C(4)-Fe(2)-Te(1)
C(4)-Fe(2)-Te(2)
C(4)-Fe(2)-Fe(1)
C(5)-Fe(2)-Te(1)
C(5)-Fe(2)-Te(2)
C(5)-Fe(2)-Fe(1)
C(2)-Fe(1)-Te(2)
C(2)-Fe(1)-Te(1)
C(2)-Fe(1)-Fe(2)
C(1)-Fe(1)-Te(2)
C(1)-Fe(1)-Te(1)
105(2)
100(2)
109(2)
156(2)
97(3)
104(3)
151(3)
89(2)
163(2)
104(2)
159(3)
85(3)
100(3)
154(2)
89(2)
61.9(3)
104.8(2)
114.4(2)
61.7(3)
103.3(2)
113.6(2)
62.0(3)
82.6(3)
59.3(3)
58.6(3)
82.7(3)
59.2(3)
58.9(3)
82.6(3)
59.4(3)
58.3(3)
112(1)
by an equatorial type of bond. This molecule actually
has a structure analogous to that of [(µ-PhS)Fe2(CO)6]2-
(µ-S-S-µ)9 with the Te atoms replacing the S atoms.
However, for the latter, two phenyl groups are attached
to S atoms, both by an axial bond, and the two butter-
fly Fe2S2 structural units are joined together by an
equatorial µ-S-S-µ bond. The Fe-Fe bond lengths in 5
(Fe(1)-Fe(2) ) Fe(3)-Fe(4) ) 2.61(1) Å) are close to
those in [(µ-PhS)Fe2(CO)6]2(µ-S-S-µ) (2.525(1) and 2.520-
(1) Å)9 and are basically the same as those in other Te/
Fe2(CO)6 compounds, such as 2.614(4) Å in [(µ-Te)(µ-
Te)2Fe2(CO)6]-2 10
2.607(6) and 2.619(7) Å in [(MeTe)-
,
95(2)
86(2)
163(2)
Fe2(CO)6]2(TeCH2Te),11 and 2.634(5) Å in (µ-MeTe)2Fe2-
(CO)6.12 Likewise, the average Fe-Te bond length,
2.536 Å, agrees very well with the 2.549 Å (average)
bond length in (µ-MeTe)2Fe2(CO)6,12 2.548 Å (average)
in (Te2CH2)Fe2(CO)6,13 2.53 Å (average) bond length in
107(1)
from RTeLi and Fe3(CO)12. (ii) Generally, in all the
products from such reactions, the greater the amount
of (µ-RTe)2Fe2(CO)6, the less of the other products. (iii)
[(µ-RTe)(µ-CO)Fe2(CO)6-] alone afforded considerable
amounts of (µ-RTe)2Fe2(CO)6. While the formation of
(µ-RTe)2Fe2(CO)6 might be expected in such reactions,
the formation of double clusers 3, 5, 7, and 9 is quite
unusual and particularly interesting but at this time
not understood. Since the anions Z alone gave only
single clusters (µ-RTe)2Fe2(CO)6, the added electrophiles
MeC(O)Cl or p-MeC6H4SO2Cl must play an important
role in the formation of the double clusters.
In order to further confirm the structures of such
double clusters, an X-ray diffraction analysis for 5 was
undertaken. One molecule of pentane was found to be
present. Selected bond lengths and angles are given in
Table 1. An ORTEP drawing with the numbering
scheme is shown in Figure 1. As seen from Figure 1, 5
has two butterfly-shaped Fe2Te2 units joined together
through an axial µ-Te-Te-µ bond; In addition, each Fe
atom is attached to three terminal carbonyl ligands and
the other two Te atoms are bound to phenyl groups, both
14
Te2Fe3(CO)9 and 2.572 Å (average) in [(µ-Te)(µ-Te)2-
Fe2(CO)6]-2 10
The Te-Te bond length, 2.826(5) Å, is
.
close to that in Ph2Te2 (2.712(2) Å)15 and in other iron
carbonyl compounds containing a Te-Te bond, such as
2.705(3)
Å , 2.807(1)
in [(µ-Te)(µ-Te)2Fe2(CO)6]-2 10
Å in CpMoFe(CO)5Te2Br,16 and 2.700(4) and 2.719(4)
Å in (Et4NCl)[(µ-Te)2Fe2(CO)6]2.17 In addition, it is
worth noting (i) that the bond angles around the Te
atoms of 5 (Fe(1)-Te(1)-Fe(2) ) 62.2(3)°, Fe(2)-Te(2)-
Fe(1) ) 61.9(3)°, Fe(3)-Te(3)-Fe(4) ) 61.7(3)°, and
Fe(4)-Te(4)-Fe(3) ) 62.0(3)°) are virtually the same
as those of (µ-MeTe)2Fe2(CO)6 (Fe(1)-Te(1)-Fe(1A) )
62.3(1)° and Fe(1)-Te(2)-Fe(1A) ) 62.2(1)°).12 (ii) The
dihedral angle between the two wings of each butterfly
Fe2Te2 skeleton of 5 are equal to 100.82° and 100.95°,
(15) Llabres, G.; Dideberg, O.; Dupont, L. Acta Crystallogr., Sect. B
1972, 28, 2488.
(16) Bogan, L. E., J r.; Rauchfuss, T. B.; Rheingold, A. L. Inorg.
Chem. 1985, 24, 3720.
(17) Bachman, R. E.; Whitmire, K. H. J . Organomet. Chem. 1994,
479, 31.

Formation of Novel Te-Containing Anions
Organometallics, Vol. 16, No. 17, 1997 3773
and 0.087 g (15%) of 3, a red-brown solid, were obtained from
the first and the second band, respectively. 3: mp 125-126
°C. Anal. Calcd for C20H18Fe4O12Te4: C, 20.29; H, 1.53.
Found: C, 20.48; H, 1.47. IR (KBr, disk): νCtO 2041 (vs), 2008
which is somewhat greater than that of (µ-MeTe)2Fe2-
(CO)6 (96.66°).12
Exp er im en ta l Section
(vs), 1983 (s) 1967 (s) cm-1
.
1H NMR (CDCl3): δ 0.73-3.17
(m, 18H, 2CH2CH2CH2CH3) ppm. MS (EI, Te130), m/z (rela-
tive intensity): 500 (Fe2TeHSC4H9(CO)6+, 0.7), 472 (Fe2Te-
HSC4H9(CO)5+, 0.6), 444 (Fe2TeHSC4H9(CO)4+, 0.8), 416 (Fe2-
TeHSC4H9(CO)3+, 2.5), 388 (Fe2TeHSC4H9(CO)2+, 2.2), 332
(Fe2TeHSC4H9+, 1.0), 331 (Fe2TeSC4H9+, 1.4), 274 (Fe2STe+,
7.5), 242 (Fe2Te+, 1.2), 186 (FeTe+, 0.3), 144 (Fe2S+, 9.0), 112
(Fe2+, 1.7), 90 (C4H9SH+, 13.1), 57 (C4H9+, 38.4), 56 (Fe+, 27.0),
41 (CH2dCHCH2+, 58), 28 (CO+, 100).
P r ep a r a tion of 4a e, 4ee, a n d 5. The intermediate salt
[(µ-PhTe)(µ-CO)Fe2(CO)6-]Li+ was prepared by the same pro-
cedure as that used for [(µ-n-BuTe)(µ-CO)Fe2(CO)6-]Li+ using
4 mL (0.609 M, 2.4 mmol) of a PhLi/Et2O solution. To this
salt was added 0.6 mL of MeC(O)Cl and the mixture was
stirred at room temperature. After workup, as in the prepara-
tion of 1 and 2, 0.302 g (44%) of 4a e, a red solid, was obtained
from the first band. 4a e: mp 104-106 °C. Anal. Calcd for
All reactions were carried out under an atmosphere of
prepurified nitrogen using standard Schlenk techniques and
monitored by TLC. Tetrahydrofuran and diethyl ether were
distilled from sodium-benzophenone ketyl under nitrogen.
Elemental Te, MeC(O)Cl, and p-MeC6H4SO2Cl were of com-
merical origin and used without further purification. Fe3-
(CO)12,18 PhCtCH,19 BuLi,20 PhLi,20 o-CH3C6H4Li,21 and
p-CH3C6H4Li21 were prepared according to literature method-
s.The products were separated first by a short column with a
ca. 10 cm-high-bed of 300-400 mesh silica gel and then by
TLC (20 × 25 × 0.25 cm, silica gel G). The products for
analysis were further purified by recrystallization from
CH2Cl2/petroleum ether. The yields were calculated after TLC
and based on elemental Te. IR spectra were recorded on a
Nicolet FT-IR 5DX spectrophotometer; 1H NMR spectra were
obtained on a J eol FX-90 Q NMR spectrometer. C/H analyses
and MS determinations were performed on a Perkin-Elmer
model 240C analyzer and an HP 5988A mass spectrometer,
respectively. Melting points were determined on a Yanaco
MP-500 apparatus.
C
18H10Fe2O6Te2: C, 31.37; H, 1.46. Found: C, 31.62; H, 1.36.
IR (KBr, disk): νCtO 2057 (s), 2000 (s), 1975 (s) 1950 (s) cm-1
.
1H NMR (CDCl3): δ 6.88-7.48 (m, 10H, 2C6H5) ppm. From
the second band was obtained 0.090 g (13%) of 4ee as a red
solid. 4ee: mp 158-160 °C. Anal. Calcd for C18H10Fe2O6-
Te2: C, 31.37; H, 1.46. Found: C, 31.53; H, 1.41. IR (KBr,
P r ep a r a tion of 1 a n d 2. To a 100 mL three-necked flask
fitted with a magnetic stir bar, a rubber septum, and a reflux
condenser topped with a nitrogen inlet tube was added 0.255
g (2.0 mmol) of tellurium powder, 30 mL of THF, and 2 mL
(1.06 M, 2.1 mol) of n-BuLi/Et2O solution. The reaction
mixture was stirred at room temperature for 2 h, and then
stirred at reflux for 30 min to give a brown solution. After
the solution was cooled to room temperature, 1.00 g (2.0 mmol)
of Fe3(CO)12 was added and the reaction mixture was stirred
for about 30 min (until no green Fe3(CO)12 remained) to give
an intermediate salt [(µ-RTe)(µ-CO)Fe2(CO)6-]Li+ (R ) n-Bu).
To this was added 0.22 mL (2.0 mmol) of phenylacetylene, and
the reaction mixture was stirred at room temperature for 10
h. The solvent was removed under reduced pressure, and the
residue was subjected to short-column chromatography and
then to TLC separation using petroleum ether as eluent. From
the first band was obtained 0.073 g (11%) of 1 as a red liquid.
Anal. Calcd for C14H18Fe2O6Te2: C, 25.90; H, 2.79. Found:
C, 26.05; H, 2.84. IR (KBr disk): νCtO 2049 (s), 2016 (vs), 1975
disk): νCtO 2057 (s), 2016 (vs), 1991 (s) 1959 (vs) cm-1
.
1H
NMR (CDCl3): δ 6.96-7.64 (m, 10H, 2C6H5) ppm. MS(EI,
Te130), m/z (relative intensity): 610 (M+ - 3CO, 0.7), 582 (M+
- 4CO, 0.4), 554 (M+ - 5CO, 0.7), 526 (M+ - 6CO, 6.1), 372
(Fe2Te2+, 27.1), 319 (Fe2TeC6H5+, 4.7), 242 (Fe2Te+, 11.4), 207
(C6H5Te+, 11.3), 186 (FeTe+, 5.1), 154 (C6H5C6H5+,100), 112
(Fe2+, 4.9), 77 (C6H5+, 68.3), 56 (Fe+, 32.8). From the third
band was obtained 0.096 g (16%) of 5, a red solid, mp 109-
110 °C. Anal. Calcd for C24H10Fe4O12Te4‚C5H12: C, 26.87; H,
1.71. Found: C, 26.32; H, 1.48. IR (KBr, disk): νCtO 2049
(vs), 2024 (vs), 1967 (vs) cm-1 1H NMR (CDCl3): δ 0.80-1.40
.
(m, 12H, 2C5H12), 7.12-7.76 (m, 10H, 2C6H5) ppm. MS (EI,
Te130), m/z (relative intensity): 505 (Fe2Te2C6H5(CO)2+, 0.7),
372 (Fe2Te2+, 14.8), 319 (Fe2TeC6H5+, 1.6), 242 (Fe2Te+, 7.8),
207 (C6H5Te+, 12.9), 186 (FeTe+, 4.6), 154 (C6H5C6H5+, 91.5),
112 (Fe2+, 3.0), 77 (C6H5+, 76.3), 56 (Fe+, 21.7).
P r ep a r a tion of 6a e, 6ee a n d 7. Method i: The intermedi-
ate salt [(µ-o-MeC6H4Te)(µ-CO)Fe2(CO)6-]Li+ was prepared
using 3 mL (0.678 M, 2.0 mmol) of a o-MeC6H4Li/Et2O solu-
tion. To this salt was added 0.60 mL of MeC(O)Cl, and the
mixture was stirred for 4 h at room temperature. After
workup, as described above, 0.453 g (63%) of 6a e, a red solid,
was obtained from the first band. 6a e: mp 74-76 °C. Anal.
Calcd for C20H14Fe2O6Te2: C, 33.49; H, 1.97. Found: C, 33.49;
H, 1.96. IR (KBr, disk): νCtO 2057 (s), 2016 (s), 1983 (s) 1959
(vs) cm-1 1H NMR (CDCl3): δ 0.64-2.72 (m, 18H, 2CH2CH2-
.
CH2CH3) ppm. From the second band was obtained 0.110
g (10%) of 2 as a red solid. mp 76-77 °C. Anal. Calcd for
C
18H16Fe2O6Te: C, 38.09; H, 2.84. Found: C, 37.72; H, 2.52.
IR (KBr disk):νCtO 2057 (s), 2016 (vs), 1991 (s) 1967 (vs) cm-1
.
1H NMR (CDCl3): δ 0.96 (t, 3H, J ) 7.2 Hz, CH3), 1.21-1.93
(m, 4H, CH2CH2CH2CH3), 2.07 (d, 1H, J ) 3.6 Hz), 2.87 (t,
2H, J ) 7.2 Hz, TeCH2), 3.55 (d, 1H, J ) 3.6 Hz), 7.23 (s, 5H,
C6H5) ppm. MS (EI, Te130), m/z (relative intensity): 570 (M+,
1.0), 542 (M+ - CO, 5.8), 514 (M+ - 2CO, 4.2), 486 (M+ - 3CO,
(vs) cm-1 1H NMR (CDCl3): δ 2.50 (s, 6H, 2CH3), 6.82-7.60
.
(m, 8H, 2C6H4) ppm. From the second band was obtained
0.063 g (9%) of 6ee, a red solid, mp 136-138 °C. Anal. Calcd
for C20H14Fe2O6Te2: C, 33.49; H, 1.97. Found: C, 33.52; H,
2.07. IR (KBr, disk): νCtO 2057 (s), 2024 (s), 1983 (s) 1959
8.9), 458 (M+ - 4CO, 1.4), 430 (M+ - 5CO, 8.7), 402 (M+
-
6CO, 11.5), 346 (Fe2(TeH)(CH2dCPh)+, 86.3), 242 (Fe2Te+,
+
76.8), 215 (Fe2CH2dCPh+, 4.6), 187 (C4H9Te+, 7.4), 112 (Fe2
,
(vs) cm-1 1H NMR (CDCl3): δ 2.55 (s, 6H, 2CH3), 6.92-7.64
.
15.6), 103 (PhCdCH2+, 100), 77 (C6H5+, 33.7), 57 (C4H9+, 17.3),
56 (Fe+, 44.7).
(m, 8H, 2C6H4) ppm. From the third band was obtained 0.034
g (5%) of 7, a deep red solid, mp 80-82 °C. Anal. Calcd for
P r ep a r a tion of 1 a n d 3. To the intermediate salt [(µ-RTe)-
(µ-CO)Fe2(CO)6-]Li+(R ) n-Bu) solution prepared as described
above was added 0.60 mL (8.5 mmol) of MeC(O)Cl. The
reaction mixture was stirred at room temperature for 4 h. After
workup, as in the preparation of 1 and 2, 0.141 g (22%) of 1
C
26H14Fe4O12Te4‚C5H12: C, 28.11; H, 1.97. Found: C, 27.93;
H, 1.53. IR (KBr, disk): νCtO 2049 (s), 2024 (vs), 1975 (vs)
cm-1 1H NMR (CDCl3): δ 0.76-1.52 (m, 12H, C5H12), 2.28-
.
2.74 (m, 6H, 2CH3), 6.86-7.60 (m, 8H, 2C6H4) ppm.
Method ii: The same procedure as described in Method i
was used, but 0.788 g (4.15 mmol) of p-MeC6H4SO2Cl instead
of MeC(O)Cl was added to give 0.477 g (67%) of a mixture of
6a e and 6ee and 0.048 g (7%) of 7.
P r ep a r a tion of 8a e, 8ee, a n d 9. The intermediate salt
[(µ-p-MeC6H4Te)(µ-CO)Fe2(CO)6-]Li+ was prepared using 3 mL
(0.824 M, 2.5 mmol) of a p-MeC6H4Li/Et2O solution. To this
salt was added 0.60 mL of MeC(O)Cl, and the mixture was
(18) King, R. B. Organometallic Syntheses, Academic Press:New
York, 1965; Vol. 1, Transition-Metal Compounds, p 95.
(19) Hessler, J . C. Organic Syntheses; J ohn Wiley: New York, 1955;
Collect. Vol. 3, p 438.
(20) J ones, R. G.; Gilman, H. Organic Reactions; J ohn Wiley and
Sons, Inc.: New York, 1951; Vol. 6, p 352.
(21) Blatt, A. H. Organic Syntheses, J ohn Wiley and Sons, Inc.: New
York, 1955, Coll. Vol. 2, p 517.

3774 Organometallics, Vol. 16, No. 17, 1997
Song et al.
1959 (vs) cm-1
7.66, 8.06, 8.16 (AA′BB′ quartet, 8H, 2C6H4) ppm.
.
1H NMR (CDCl3): δ 2.50 (s, 6H, 2CH3), 7.56,
Ta ble 2. Cr ysta l Da ta Collection a n d Refin em en t
of 5
Sin gle-Cr ysta l Str u ctu r e Deter m in a tion of 5. Single
crystals of 5 suitable for X-ray diffraction were obtained by
mol form
mol wt
cryst syst
C29H22Fe4O12Te4
1296.27
triclinic
slow evaporation of its CH2Cl2/petroleum ether solution.
A
space group
a, Å
b, Å
c, Å
P1h (No. 2)
crystal measuring 0.25 × 0.40 × 0.65 mm was mounted on a
glass fiber and placed on an Enraf-Nonius CAD4 diffractome-
ter with a graphite monochromator. A total of 7062 indepen-
dent reflections were collected at 23 °C with Mo KR (λ )
0.710 69 Å) radiation by a ω-2θ scan mode. Of the total
number of independent reflections, 1937 with I g 3σ(I) were
considered to be observed and used in subsequent refinement.
Data were corrected for Lp factors. The crystal belongs to the
triclinic space group P1h (No. 2), with a ) 11.570(7) Å, b )
11.94(1) Å, c ) 15.69(1) Å; R ) 106.64(6)°, â ) 102.45(6)°, γ )
81.43(6)°; V ) 2020(3) Å3; Z ) 2; Dc ) 2.13 g‚cm-3; µ ) 43.01
cm-1; F(000) ) 1208.
11.570(7)
11.94(1)
15.69(1)
106.64(6)
102.45(6)
81.43(6)
2020(3)
2
2.13
1208
43.01
Enraf-Nonius CAD4
23
R, deg
â, deg
γ, deg
V, Å3
Z
density (calcd), g‚cm-3
F(000)
µ(Mo KR), cm-1
diffractometer
temp, °C
The structure was solved by direct methods. Fe atoms, Te
atoms, and most of the oxygen atoms were subjected to the
structure refinement with anisotropic temperature factors. All
carbon atoms and the O(5) atom were subjected to structure
refinement with isotropic temperature factors. All hydrogen
atoms of the molecule except pentane were generated geo-
metrically and allowed to ride on their respective parent C
atoms. The unweighted and weighted agreement factors are
0.090 (R) and 0.093 (Rw), respectively. The highest peak on
the final difference Fourier map has a height of 1.24 eÅ-3. All
calculations were performed on a Micro-Vax 3100 computer
using the TEXSAN program system. Details of crystal pa-
rameters, data collection, and structure refinement are given
in Table 2.
radiation
scan type
2θ max, deg
no. of obs, n
no. of variables, p
R
Rw
goodness-of-fit indicator
max shift in final cycle
largest peak in final diff map, e Å-3
Mo KR(λ ) 0.710 69 Å)
ω/2θ
50
1937
300
0.090
0.093
1.65
0.25
1.24
stirred for 4 h at room temperature. After workup, as
described above, 0.270 g (38%) of 8a e, a red solid, was obtained
from the first band. 8a e: mp 136-137 °C. Anal. Calcd for
C
20H14Fe2O6Te2: C, 33.49; H, 1.97. Found: C, 33.35; H, 1.77.
IR (KBr, disk): νCtO 2049 (s), 2024 (s), 1983 (vs) 1967 (vs) cm-1
.
Ack n ow led gm en t. We are grateful to the National
Natural Science Foundation of China and State Key
Laboratory of Elemento-Organic Chemistry for financial
support of this work.
1H NMR (CDCl3): δ 2.31 (s, 6H, 2CH3), 6.93, 6.97, 7.12, 7.16
(AA′BB′ quartet, 4H, C6H4), 7.00, 7.04, 7.24, 7.28 (AA′BB′
quartet, 4H, C6H4) ppm. From the second band was obtained
0.098 g (14%) of 8ee, a red solid, mp 129-130 °C. Anal. Calcd
for C20H14Fe2O6Te2: C, 33.49; H, 1.97. Found: C, 33.08; H,
Su p p or tin g In for m a tion Ava ila ble: Text giving crystal-
lographic experimental data and tables of data collection and
processing parameters, positional and thermal parameters,
bond lengths, and bond angles for 5 (5 pages). Ordering
information is given on any current masthead page.
1.70. IR (KBr, disk): νCtO 2057 (s), 2016 (s), 1967 (vs) cm-1
.
1H NMR (CDCl3): δ 2.36 (s, 6H, 2CH3), 7.01, 7.11, 7.31, 7.41
(AA′BB′ quartet, 8H, 2C6H4) ppm. From the third band was
obtained 0.073 g (12%) of 9, a red solid, mp 128 °C (dec). Anal.
Calcd for C26H14Fe4O12Te4: C, 24.94; H, 1.13. Found: C, 25.09;
H, 1.22. IR (KBr, disk): νCtO 2049 (vs), 2024 (vs), 1983 (vs)
OM970272J