Mixed-valence manganese carbonyl complexes with supersilyl thiolate ligands: [(OC)4Mn(μ -SSitBu3)2Mn(THF)X] (X = Br, SSitBu3) and Na(THF)6[(OC)3Mn(μ-SSi/Bu 3)3MnSSitBu3]

Article abstract of DOI:10.1021/om800211k

The manganese carbonyl thiolates [(OC)₄Mn(μ-SSitBu ₃)₂Na(THF)₂], [(OC)₄Mn(μ- SSitBu₃)₂Mn(THF)Br], [(OC)₄Mn(μ-SSitBu ₃)₂Mn(THF)SSitBu₃], and Na(THF) ₆[(OC)₃Mn(μ-SSitBu₃) ₃MnSSitBu₃] can be prepared from the precursors Na(THF)₂SSitBu₃ and [Mn(CO)₅Br]. When [Mn(CO)₅Br] is treated with 1 or 2 equiv of Na(THF) ₂SSkBu₃, the 1:2 substitution product [(OC) ₄Mn(a-SSitBu₃)₂Na(THF)₂] (monoclinic, P2₁/C) is formed quickly. When additional amounts of [Mn(CO)₅Br] are present (as in the 1:1 reaction) or are subsequently added to the reaction mixture, the dinuclear Mn(I)Mn(II) complex [(OC) ₄Mn(μ-SSitBu₃)₂Mn(THF)Br] (monoclinic, P2₁/n) can be obtained along with [Mn₂(CO)₁₀]. Treatment of [(OC)₄Mn(μ-SSitBu₃)₂Mn(THF)Br] with 1 equiv of Na(THF)₂SSitBu₃ gives the mixed-valence dinuclear manganese thiolate complex [(OC)₄Mn(μ-SSitBu ₃)₂Mn(THF)SSitBu₃] (monoclinic, C2/c). Cocrystals of the Mn(I)Mn(II)_species Na(THF)₆[(OC) ₃Mn(μ-SSitBu₃)₃MnSSitBu₃] with the trisulfane tBu₃Si-SSS-SitBu₃ (trigonal, R3) are obtained by the reaction of [Mn(CO)₅Br] with 2 equiv of Na(THF) ₂SSitBu₃. The complex anion [(OC)₃Mn(μ- SSitBu₃)₃MnSSitBu₃r contains a terminal thiolate ligand with a linear Mn-S-Si unit.

Full text of DOI:10.1021/om800211k

3
272
Organometallics 2008, 27, 3272–3278
Mixed-Valence Manganese Carbonyl Complexes with Supersilyl
Thiolate Ligands: [(OC) Mn(µ-SSitBu ) Mn(THF)X] (X ) Br,
4
3 2
SSitBu ) and Na(THF) [(OC) Mn(µ-SSitBu ) MnSSitBu ]
3
6
3
3 3
3
Theresa I. K u¨ ckmann, Frauke Sch o¨ del, Inge S a¨ nger, Michael Bolte, Matthias Wagner, and
Hans-Wolfram Lerner*
Institut f u¨ r Anorganische Chemie, Johann Wolfgang Goethe-UniVersit a¨ t Frankfurt am Main,
Max-Von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany
ReceiVed March 7, 2008
The manganese carbonyl thiolates [(OC)
THF)Br], [(OC) Mn(µ-SSitBu
be prepared from the precursors Na(THF)
or 2 equiv of Na(THF) SSitBu
monoclinic, P2 /c) is formed quickly. When additional amounts of [Mn(CO)
:1 reaction) or are subsequently added to the reaction mixture, the dinuclear Mn(I)Mn(II) complex
Mn(THF)Br] (monoclinic, P2 /n) can be obtained along with [Mn (CO)10].
Mn(µ-SSitBu Mn(THF)Br] with 1 equiv of Na(THF)
valence dinuclear manganese thiolate complex [(OC) Mn(µ-SSitBu Mn(THF)SSitBu
c). Cocrystals of the Mn(I)Mn(II) species Na(THF) [(OC) Mn(µ-SSitBu MnSSitBu
(trigonal, R3) are obtained by the reaction of [Mn(CO) Br] with 2 equiv of
] contains a terminal thiolate
4
Mn(µ-SSitBu
3
3
)
2
Na(THF)
], and Na(THF) [(OC) Mn(µ-SSitBu
and [Mn(CO) Br]. When [Mn(CO)
Mn(µ-SSitBu
Br] are present (as in the
2
], [(OC)
4
Mn(µ-SSitBu
MnSSitBu
Br] is treated with
Na(THF)
3
)
3
2
Mn-
] can
(
4
)
3 2
Mn(THF)SSitBu
6
3
3
)
3
2
SSitBu
3
5
5
1
(
2
3
, the 1:2 substitution product [(OC)
4
3
)
2
2
]
1
5
1
[
(OC)
4
Mn(µ-SSitBu
3
)
2
1
2
Treatment of [(OC)
4
3
)
2
2
SSitBu
3
gives the mixed-
4
)
3 2
3
] (monoclinic, C2/
6
3
3
)
3
3
] with the trisulfane
j
tBu
Na(THF)
3
Si-SSS-SitBu
SSitBu . The complex anion [(OC)
3
5
-
2
3
3
3 3 3
Mn(µ-SSitBu ) MnSSitBu
ligand with a linear Mn-S-Si unit.
Introduction
possibility of further manipulation. For example, in
Mn(CO)5Br] the bromo ligand could be exchanged for a
chalcogenolate, leaving unreacted CO ligands. Up to now
manganese dinuclear carbonyl thiolate complexes of the type
[
In a number of recent studies, bulk silyl chalcogenolate
-
ligands of the type ESiR3 (E ) O, S, Se, Te) have been used
1
,2
to stabilize transition-metal centers.
In macromolecular
[
(OC)4Mn(µ-SR)2Mn(CO)4],[Mn(µ3-SR)(CO)3]4,and[(OC)3Mn(µ-
chemistry, silyl chalcogenolates have also found application.
Cyclic thiolates of the general form [M(SSitBu3)X]n (M ) Fe,
Co, Ni; X ) Cl, Br, I; n ) 12, 14) can be prepared by heating
-
SR)3Mn(CO)6] are known and have been structurally charac-
terized (Scheme 1). Only with pentafluorobenzenethiol was
it possible to isolate and characterize a mononuclear pentacar-
6
–8
3
solvated monomeric or dimeric precursors under vacuum.
9
,10
bonyl complex of the type [Mn(CO)5SR] (R ) C6F5).
It is
Disilyl chalcogenides (Me3Si)2E (E ) S, Se) have been
employed in the synthesis of polynuclear metal clusters, driven
by the release of Me3SiX when (Me3Si)2E is treated with metal
halides MXn. Structural studies of the phosphanediides
M2PSitBu3], which are isoelectronic with tri-tert-butylsilyl
supersilyl) thiolates, also reveal metal-metal interactions. It
is interesting to note that in [Ag2PSitBu3]8 the Ag atoms feature
an Ag16 cluster. The polyhedron formed by that cluster belongs
interesting to note that treatment of [Mn(CO)5Br] with organic
thiolates SR- normally affords tetrameric species, [Mn(µ3-
SR)(CO)3]4, rather than mononuclear complexes [Mn(CO)5SR].
The tricarbonylmanganese(I) organylthiolates [Mn(µ-SR)(CO)3]n
(R ) nBu, Ph) were originally reported to be trimeric (n ) 3),
and a structure involving a triangular metal atom cluster was
4
[
(
5
5
10
proposed. However, subsequent mass spectral studies indicated
to the family of the Johnson polyhedra and is a Square
gyrobicupola (J29).
Another approach to complexes with chalcogen coordination
is to start from materials which after salt metathesis leave the
that, in the vapor phase, a tetrameric formulation rather than a
1
1
trimeric one is more correct. In addition, the results of the
X-ray structure analysis of tricarbonylmanganese(I) benzenethi-
olate confirm the tetrameric nature of this type of manganese
7
,12,13
carbonyl complex.
*
To whom correspondence should be addressed. Fax: +49-69-798-
2
9260. E-mail: lerner@chemie.uni-frankfurt.de.
(
(
1) Arnold, J. Prog. Inorg. Chem. 1995, 43, 353.
(6) Chen, J.; Young, V. G., Jr.; Angelici, R. J. Organometallics 1996,
15, 325. Vahrenkamp, H. Angew. Chem., Int. Ed. 1975, 14, 322.
(7) Onaka, S.; Katukawa, Y. J. Coord. Chem. 1996, 39, 135.
(8) Fenske, D.; Meyer, J. J.; Merzweiler, K. Z. Naturforsch., B: Chem.
1987, 42, 1207. Liaw, W.-F.; Lee, C.-M.; Homg, L.; Lee, G.-H.; Peng,
S.-M. Organometallics 1999, 18, 782.
2) Kückmann, T. I.; Hermsen, M.; Bolte, M.; Wagner, M.; Lerner, H.-
W. Inorg. Chem. 2005, 44, 3449.
3) Sydora, O. L.; Henry, T. P.; Wolczanski, P. T.; Lobkovsky, E. B.;
Rumberger, E.; Hendrickson, D. N. Inorg. Chem. 2006, 45, 609.
4) Fenske, D.; Ohmer, J.; Hachgenei, J.; Merzweiler, K. Angew. Chem.,
(
(
Int. Ed. 1988, 27, 1277. Fenske, D.; Corrigan, J. F. In Metal Clusters in
Chemistry; Braunstein, P., Oro, L. A., Raithby, P. R., Eds.; Wiley-VCH:
Weinheim, Germany, 1999; Vol. 3, p 1302.
(9) Treichel, P. M.; Tegen, M. H. Inorg. Synthesis 1989, 25, 115.
(10) Osborne, A. G.; Stone, F. G. A. J. Chem. Soc. A 1966, 1143.
(11) Johnson, B. F. G.; Pollick, P. J.; Williams, I. G.; Wojcicki, A. Inorg.
Chem. 1968, 7, 831.
(
5) Lerner, H.-W.; Margraf, G.; Bats, J.; Wagner, M. Chem. Commun.
2
005, 4545. Lerner, H.-W.; Bolte, M.; Karaghiosoff, K. K.; Wagner, M.
Organometallics 2004, 23, 6073. Lerner, H.-W.; Wagner, M.; Bolte, M.
Chem. Commun. 2003, 990.
(12) Herbstein, F. H.; Hu, S.; Kapon, M. Acta Crystallogr., Sect. B 2002,
B58, 884.
(13) Osborne, A. G.; Stone, F. G. A. J. Chem. Soc. A 1966, 1143.
1
0.1021/om800211k CCC: $40.75  2008 American Chemical Society
Publication on Web 06/03/2008

Manganese Complexes with Supersilyl Thiolate Ligands
Scheme 1. Synthesis of [Mn(CO) SR] and of [Mn(µ
Organometallics, Vol. 27, No. 13, 2008 3273
5
3
-SR)-
Scheme 2. Synthesis of Dinuclear Mn(I) Thiolates of the
a
a
(
CO)
3
]
4
4 2 4
Type [(OC) Mn(µ-SR) Mn(CO) ]
a
-
-
Legend: (i) +SR (e.g. R ) Me, Et, Ph, Tol), -Br (X ) Br); (ii)
HSR (R ) C ), -H (X ) H).
+
6
F
5
2
Dinuclear complexes of the type [(OC)4Mn(µ-SR)2Mn(CO)4]
were prepared (i) by oxidation of the pentacarbonyl anion
a
Legend: (i) +HSR (R ) C
Me, Ph, CF ), -CO; (iii) + H
(e.g. R ) Me, Tol), -C S.
6
F
5
), -CO, -H
2
; (ii) +RSSR (e.g. R )
-
3
2
, -H CdCMeMeCdCH ; (iv) +SR
2
2
Mn(CO)5]- with disulfides RSSR,
14,15
(ii) by treating the
[
4 4
H
9
,10
hydrido complex H[Mn(CO)5] with thiols HSR.
hydrogenation of [(1-phenylthiophene)Mn(CO)3], or (iv) by
reaction of the [(thiophene)Mn(CO)3] cation with thiolates
SR , as shown in Scheme 2. However, the formation of
(OC)4Mn(µ-SR)2Mn(CO)4] thereby must be complicated, since
(iii) by
1
2
+
reaction partner of [Mn(CO)5Br], some novel insight into the
aggregation between thiolate ligands and Mn(I) centers can be
expected.
-
6
[
each Mn center has three or five CO ligands in the beginning
when it is used as starting material but the reaction product
possesses four CO ligands.
Results and Discussion
Surprisingly, the reaction of Na(THF)2SSitBu3 with
Chalcogenolates such as SSitBu3- can donate a varying
[
Mn(CO)5Br], as shown in Scheme 3, is quite different from
those between [Mn(CO)5Br] and organyl thiolates. When
Mn(CO)5Br] is treated with only 1 equiv of Na(THF)2SSitBu3,
immediate gas evolution is observed, and the reaction mixture
quickly becomes heterogeneous. After 2 h, NMR spectra ( H,
16,17
number of electrons when bound to a transition-metal center.
As pure σ donors, they donate two electrons to a coordinated
metal site. The free p orbital lone pairs, however, can both
potentially donate in a π fashion. This corresponds to four- or
six-electron donation. The necessary prerequisite for six-electron
donation is linear M-E-Si coordination. This coordination
geometry can only be effectively induced by sterically hindered
residues. These, by their very nature, have a large coordination
[
1
13
29
C, and Si) show that Na(THF)2SSitBu3 has been completely
consumed, and the dominant signals can be assigned to the 1:2
product Na(THF)2[(OC)4Mn(SSitBu3)2] (1) (Scheme 3).
The thiolate complex 1, however, reacts with the remaining
-
cone angle (ca. 120° for OSitBu3 ), making them comparable
1
equiv of [Mn(CO)5Br], and the new products [(OC)4Mn(µ-
to Cp (cone angle ca. 130°) both in their electron donation (6e)
SSitBu3)2Mn(THF)Br] (2) and [Mn2(CO)10] are formed. When
the solvent is changed from THF to pentane, and the concen-
trated filtrate is left to stand for 2 weeks at -20 °C, orange
crystals can be isolated. The solid-state structure, however, does
not reveal the expected thiolate complex 2 but rather the
Mn(I)Mn(II) complex [(OC)4Mn(µ-SSitBu3)2Mn(THF)SSitBu3]
1
8
and in their steric demands. This sort of coordination and
electron donation has rarely been observed for silyl chalcogen-
1
6,19
olates.
Due to the bulky residue SitBu3 the formation of a
linear Si-S-Mn unit is possible and thus six-electron donation
is more likely. Such silyl chalcogenolates are thus, in a sense,
isolobal with the cyclopentadienyl ligand.
(
3). However, the mixed-valence dinuclear manganese thiolate
In this paper, we describe the reaction of [Mn(CO)5Br] with
Na(THF)2SSitBu3 in a 1:1 and 1:2 stoichiometry, respectively.
When the extremely bulky supersilyl thiolate is employed as a
complex 2 was obtained when a purified sample of 1 was treated
with 2 equiv of [Mn(CO)5Br] (Scheme 3). Thereby [Mn2(CO)10]
was obtained as a byproduct, which was identified in the IR
spectrum, whereas the complex 2 was characterized by X-ray
structure analysis. Apparently, due to the weak-field ligands THF
and bromide, Mn(I) centers disproportionate in the presence of
SSitBu3- to [Mn2(CO)10] and Mn(II) (Scheme 3). However, 2
can be transformed easily with Na(THF)2SSitBu3 into 3.
When [Mn(CO)5Br] in THF is treated with 2 equiv of
Na(THF)2SSitBu3, the reaction initially proceeds as described
above using 1 equiv of thiolate. After 3 h, the thiolate
(
(
(
(
(
14) Treichel, P. M.; Nakagaki, P. C. Organometallics 1986, 5, 711.
15) Alper, H.; Paik, H.-N. J. Organomet. Chem. 1976, 121, 225.
16) Bonasia, P. J.; Arnold, J. Inorg. Chem. 1992, 31, 2508.
17) Wolczanski, P. T. Polyhedron 1995, 14, 3335.
18) Lerner, H.-W.; Scholz, S.; Bolte, M. Organometallics 2002, 21,
3
827. Tolman, C. A. Chem. ReV. 1977, 77, 313.
(19) Ananikov, V. P.; Beletskaya, I. P.; Aleksandrov, G. G.; Eremenko,
I. L. Organometallics 2003, 22, 1414.

3
274 Organometallics, Vol. 27, No. 13, 2008
Kückmann et al.
a
5 2 3
Scheme 3. Reaction of [Mn(CO) Br] with Na(THF) SSitBu
Figure 1. Thermal ellipsoid plot of 1 showing the atomic numbering
scheme. The displacement ellipsoids are drawn at the 30%
probability level. H atoms have been omitted for clarity. Selected
bond lengths (Å) and angles (deg): Mn(1)-C(7) ) 1.868(6),
Mn(1)-C(8) ) 1.785(6), Mn(1)-S(1) ) 2.480(1), Na(1)-S(1) )
2
.744(3), S(1)-Si(1) ) 2.144(2), S(1)-Mn(1)-S(2) ) 83.67(5),
Mn(1)-S(1)-Na(1))99.69(6),Mn(1)-C(9))1.874(6),Mn(1)-C(10)
1.802(6), Mn(1)-S(2) ) 2.475(2), Na(1)-S(2) ) 2.757(2),
)
S(2)-Si(2))2.151(2),S(1)-Na(1)-S(2))73.86(6),Mn(1)-S(2)-Na(1)
)
99.47(6).
2
9
Si NMR signal for 1 (C6D6: 29.5 ppm) is shifted downfield
compared to that of the sodium thiolate Na(THF)2SSitBu3 (25.6
ppm).
The IR stretching frequencies of 1 (CH2Cl2 solution) are
a
-1
Legend:
R
)
SitBu
3
;
(i) +2NaR, -NaBr, THF; (ii)
(CO)10]; (iii) +NaSR,
shifted to lower frequencies by 30-40 cm compared to
+
-
2[Mn(CO)
NaBr; (iv) +NaSR, -CO.
5
Br], -NaBr, -5CO, -0.5[Mn
2
reported complexes of the type [(OC)4Mn(µ-SR)2Mn(CO)4] and
6
,7,12,22
[
Mn(µ3-SR)(CO)3]4.
This result can be rationalized by
assuming that the thiolate ligands will act as stronger σ donors
toward a Mn center in the case of 1 rather than toward two Mn
centers as in [(OC)4Mn(µ-SR)2Mn(CO)4] and three Mn centers
as in [Mn(µ3-SR)(CO)3]4, leading to stronger Mn-CO back-
bonding and consequently lower CO stretching frequencies in
the complex 1 than in [(OC)4Mn(µ-SR)2Mn(CO)4] and [Mn(µ3-
SR)(CO)3]4, respectively. In the carbonyl stretching region of
the IR spectrum, the thiolates 2 and 3 show bands of intensity
similar to those in the spectrum of 1.
Na(THF)2SSitBu3 has been completely consumed (as determined
by NMR spectroscopy). Changing the solvent to pentane,
filtering, and slowly concentrating the filtrate leads to deposition
of X-ray-quality crystals of 1 (Scheme 3).
When a 1:2 reaction mixture of [Mn(CO)5Br] and
Na(THF)2SSitBu3 is left to stand for a period of several weeks,
a few crystals with unit cell parameters different from those of
crystals of 1 can be isolated. These contain the mixed-valence
manganese complex anion Na(THF)6[(OC)3Mn(µ-SSitBu3)3-
Mn(THF)SSitBu3] (4) and the trisulfane tBu3Si-SSS-SitBu3.
The formation of 4 can be explained by the reaction of the
mixed-valence dinuclear manganese thiolate complex 3 with
NaSSitBu3 (Scheme 3). It is interesting to note that the trisulfane
tBu3Si-SSS-SitBu3 represents a typical oxidation product of
The dinuclear manganese complexes 2 and 3 are paramag-
netic, since charge balance dictates that they contain one Mn(I)
6
5
(
d ) and one Mn(II) (d ) center. In order to quantify this effect,
the Evans method was applied for 3, and µeff was determined
2
3
to be 4.9 µB, corresponding to four unpaired electrons. This
2
0,21
outcome confirms the strong paramagnetism of the dinuclear
the sodium thiolate NaSSitBu3.
Generally, the NMR spectra of manganese carbonyl thiolate
resemble those of the thiolate ligand Na(THF)2SSitBu3. The
2
(
22) Treichel, P. M. In ComprehensiVe Organometallic Chemistry; Abel,
1
E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon Press: London, 1982;
Vol. 3, p 103.
(
(
20) Wiberg, N. Coord. Chem. ReV. 1997, 163, 217.
(23) Evans, D. F. J. Chem. Soc. 1959, 2003–2005. Schubert, E. M.
J. Chem. Educ. 1992, 69, 62.
21) Schuster, H. Ph.D. Thesis, University of Munich, Munich, 1991.

Manganese Complexes with Supersilyl Thiolate Ligands
Organometallics, Vol. 27, No. 13, 2008 3275
Table 1. Selected Bond Lengths (Å) and Angles (deg) for the Manganese Carbonyl Thiolates 1-4
1
2
3
4
Mn-C
1.832(6) (av)
2.478(2) (av)
1.839(4) (av)
2.459(1) (av)
1.822(10) (av)
2.506(2) (av)
2.349(2)
2.094(3)
2.210(3) (av)
3.738
1.769(9)
2.484(2)
2.269(5)
2.064(6)
2.152(3)
3.063(3)
180.0(1)
Mn-S(bridging)
Mn-S(terminal)
Si-S(terminal)
Si-S(bridging)
Mn-M (M ) Mn, Na)
Mn-S(terminal)-Si
2.148(2) (av)
3.997
2.187(2) (av)
3.546
130.9(2)
Mn(I)Mn(II) complex 3, but it is inconsistent with the expected
result of µeff ) 5.9 µB for a high-spin Mn(II) center (five
unpaired electrons). Since the Evans method is sensitive to the
concentration of analyte in the solution, it is possible that, despite
careful washing, the sample of 3 was contaminated with
diamagnetic species which would decrease the overall para-
magnetism of the sample, leading to a smaller experimental
value for µeff.
molecule) to 138.1(2)° (O(71)-Na(1)-S(2) ) 134.51° for the
second molecule). Furthermore, the Mn-S bond lengths are the
longest found for a structurally characterized (CO)4Mn-SR
2
6
compound (Table 1).
The mixed-valence manganese silyl thiolate 2, shown in
Figure 2, crystallizes in the monoclinic space group P21/n
(selected bond lengths and angles in Table 1 and the figure
caption). The two Mn atoms and two sulfur atoms of thiolate
ligands form a nearly planar square. The S-Mn-S angles, at
The crystal structure of the manganese carbonyl thiolate 1 is
shown in Figure 1; selected bond lengths and angles can be
found in the corresponding caption and in Table 1. X-ray-quality
crystals of 1 were grown from pentane. This complex crystallizes
in the monoclinic space group P21/c with two crystallographi-
cally independent molecules in the asymmetric unit. These two
molecules, however, display very similar structural parameters,
and only one is shown in Figure 1. The core of 1 is formed by
a four-membered MnS2Na ring in which two bridging thiolate
ligands bind to both the manganese and the sodium atom.
Although a number of structurally characterized dimanganese
complexes with (OC)4Mn moieties and bridging thiolate ligands
8
3.18(3)° (average), and the Mn-S-Mn angle, at 92.29(3)°
(
average), deviate slightly from 90°, while the Mn-S bond
lengths, which average 2.45562(9) Å, are somewhat shorter than
those found in 1, 3, and 4. The MnMn distance is quite long
(3.546 Å), suggesting only a weak interaction between the metal
centers. Similar structural motifs have been observed for
dinuclear Mn(I)Mn(I) thiolate complexes. The related complexes
6
[
(OC)4Mn(µ-SC6H4Me-p)2Mn(CO)4] and [(OC)4Mn(µ-SPh)2-
6
,22,24
are known in the literature,
heterodinuclear complexes are
2
5
less common, and none with alkali metals have been re-
2
5
ported. In contrast to the Na2E2 four-membered rings formed
by the sodium chalcogenolates Na(THF)2SSitBu3, the M-S-M
angles in 1 are significantly larger than 90°, while the S-M-S
angles are smaller than 90°. Furthermore, the core four-
membered rings of the sodium supersilyl chalcogenolates are
planar, but the M2S2 unit in 1 is bent. The two planes defined
by sodium, manganese, and one sulfur atom meet at an angle
of 21.3° (29.1° for the second molecule), while the S2Mn plane
meets the S2Na plane at an angle of 17.8° (24.8° for the second
molecule).
The Mn atom is coordinated in a distorted-octahedral fashion.
Those C-Mn-C and C-Mn-S angles which are closest to
9
0° range between 82.2(2)° (C(7)-Mn(1)-S(2)) and 97.9(2)°
(
C(8)-Mn(1)-S(1)) for the first molecule and 80.2(2)°
(C(7A)-Mn(1A)-S(2A)) and 99.1(2)° (C(9A)-Mn(1A)-S(2A))
for the second molecule, while those that are close to linearity
are between 172.2(2)° (C(8)-Mn(1)-S(2)) and 175.0(2)°
(
1
C(7)-Mn(1)-C(9)) for the first molecule and 169.2(2)° and
75.7(2)° for the second molecule. The sodium atom has a
Figure 2. Thermal ellipsoid plot of 2 showing the atomic numbering
scheme. The displacement ellipsoids are drawn at the 30% probability
level. H atoms have been omitted for clarity. Selected bond lengths
distorted coordination sphere, with L-Na-L angles ranging
from 73.86(6)° (S(1)-Na(1)-S(2) ) 73.75(6)° for the second
(
2
Å) and angles (deg): Mn(1)-O(71) ) 2.132(2), Mn(1)-S(1) )
.4368(9), Mn(1)-Br(1) ) 2.4380(6), Mn(1)-S(2) ) 2.4478(9),
Mn(2)-C(2) ) 1.794(4), Mn(2)-C(1) ) 1.797(4), Mn(2)-C(3) )
.877(4), Mn(2)-C(4) ) 1.889(4), Mn(2)-S(2) ) 2.4710(9),
Mn(2)-S(1) ) 2.4800(9), S(1)-Si(1) ) 2.1887(12), S(2)-Si(2) )
.1846(11), C(1)-O(1) ) 1.155(4), C(2)-O(2) ) 1.159(4), C(3)-O(3)
(
24) Winter, A.; Huttner, G.; Gottlieb, M.; Jibril, I. J. Organomet. Chem.
1
985, 286, 317. Lindner, E.; Auch, K.; Hiller, K.; Fawzi, R. Z. Naturforsch.,
1
B: Chem. 1987, 42, 454. Grobe, J.; Vetter, J.; Krebs, B.; Pascaly, M. Z.
Anorg. Allg. Chem. 626, 430. Mace, W. J.; Main, L.; Nicholson, B. K.;
Hagyard, M. J. Organomet. Chem. 2002, 664, 288. Zhang, X.; Dullaghan,
C. A.; Carpenter, G. B.; Swaigart, D. A.; Meng, Q. Chem. Commun. 1998,
2
) 1.133(4), C(4)-O(4) ) 1.128(4), O(71)-Mn(1)-S(1) ) 104.97(6),
O(71)-Mn(1)-Br(1) ) 115.07(6), S(1)-Mn(1)-Br(1) ) 122.38(3),
O(71)-Mn(1)-S(2) ) 100.70(7), S(1)-Mn(1)-S(2) ) 83.86(3),
Br(1)-Mn(1)-S(2) ) 124.22(3), S(2)-Mn(2)-S(1) ) 82.49(3),
Si(1)-S(1)-Mn(1) ) 124.34(4), Si(1)-S(1)-Mn(2) ) 134.63(4),
Mn(1)-S(1)-Mn(2) ) 92.31(3), Si(2)-S(2)-Mn(1) ) 126.50(4),
Si(2)-S(2)-Mn(2) ) 133.65(4), Mn(1)-S(2)-Mn(2) ) 92.26(3).
9
3. Dullaghan, C. A.; Carpenter, G. B.; Sweigart, D. A.; Choi, D. S.; Lee,
S. S.; Chung, Y. K. Organometallics 1997, 16, 5688. Zhang, X.; Dullaghan,
C. A.; Watson, E. J.; Carpenter, G. B.; Sweigart, D. A. Organometallics
1
998, 17, 2067. Herberhold, M. M.; Milius, W.; Liu, J. Z. Naturforsch., B:
Chem. 2004, 59, 673. McDonald, J. W. Inorg. Chem. 1985, 24, 1734.
25) Komiya, S.; Muroi, S.-Y.; Furuya, M.; Hirano, M. J. Am. Chem.
Soc. 2000, 122, 170.
(

3
276 Organometallics, Vol. 27, No. 13, 2008
Kückmann et al.
Figure 4. Thermal ellipsoid plot of the anion of 4 showing the
atomic numbering scheme. The displacement ellipsoids are drawn
at the 30% probability level. H atoms have been omitted for clarity.
Selected bond lengths (Å) and angles (deg): Mn(1)-C(1) )
Figure 3. Thermal ellipsoid plot of 3 showing the atomic numbering
scheme. The displacement ellipsoids are drawn at the 30%
probability level. H atoms have been omitted for clarity. Selected
bond lengths (Å) and angles (deg): Mn(1)-C(1) ) 1.832(9),
Mn(1)-C(2) ) 1.788(10), Mn(1)-C(3) ) 1.844(9), Mn(1)-C(4)
1
.769(9), Mn(1)-S(1) ) 2.496(2), Mn(1)-Mn(2) ) 3.063(3),
Mn(2)-S(2) ) 2.269(5), S(1)-Si(1) ) 2.152(3), S(2)-Si(2) )
.064(6), S(1)-Mn(2) ) 2.471(2), C(1)#1-Mn(1)-C(1) ) 91.0(4),
2
C(1)#1-Mn(1)-S(1) ) 84.4(3), C(1)#2-Mn(1)-S(1) ) 100.2(3),
C(1)-Mn(1)-S(1) ) 167.9(3), S(1)-Mn(1)-S(1)#1 ) 85.43(8),
S(1)#1-Mn(2)-S(1)#2 ) 86.50(8), S(2)-Mn(2)-S(1) ) 127.71(6),
Si(2)-S(2)-Mn(2) ) 180.000(1), Si(1)-S(1)-Mn(2) ) 126.16(10),
Si(1)-S(1)-Mn(1) ) 134.32(10), Mn(2)-S(1)-Mn(1) ) 76.14(7).
Symmetry transformations used to generate equivalent atoms: (#1)
)
1.822(9), Mn(1)-S(1) ) 2.543(2), Mn(1)-S(2) ) 2.484(2),
Mn(2)-S(1) ) 2.478(2), Mn(2)-S(2) ) 2.517(2), Mn(2)-S(3) )
.349(2), Mn(2)-O(51) ) 2.145(6), S(1)-Mn(1)-S(2) ) 81.41(7),
2
S(1)-Mn(2)-S(2) ) 82.04(7), Mn(1)-S(1)-Mn(2) ) 96.20(8),
Mn(1)-S(2)-Mn(2) ) 96.73(8), O(51)-Mn(2)-S(3) ) 94.2(2),
O(51)-Mn(2)-S(1) ) 104.6(2), S(1)-Mn(2)-S(3) ) 127.45(9),
O(51)-Mn(2)-S(2) ) 101.1(2), S(2)-Mn(2)-S(3) ) 141.94(9),
Si(3)-S(3)-Mn(2) ) 130.9(2).
-y + 1, x - y, z; (#2) -x + y + 1, -x + 1, z.
linearly bound thiolate in 4, supporting the conclusion that a
bent coordination angle leads to less electron donation from
the thiolate ligand.
7
,12
Mn(CO)4]
both display a central Mn2S2 four-membered ring,
feature Mn-Mn distances of 3.606 and 3.594 Å and average
Mn-S bond lengths of 2.394(1) and 2.395(2) Å, respectively.
The distances between 1.128(4) and 1.159(4) Å in 2 have a
characteristic length for MnC-O bonds.
The mixed-valence manganese carbonyl thiolate complex 4
(anion of 4 shown in Figure 4; selected bond lengths and angles
in Table 1 and the corresponding figure caption), cocrystallizes
Complex 3 crystallizes in the monoclinic space group C2/c
with one complete molecule in the asymmetric unit (Figure 3,
selected bond lengths and angles in Table 1 and the correspond-
ing figure caption). The core of the complex is formed by a
Mn2S2 four-membered ring. As in 2, the S-Mn-S angles are
considerably smaller than 90°, while the Mn-S-Mn angles are
considerably larger. Mn(1) is coordinated by four terminal
carbonyl ligands and two bridging thiolates in a distorted-
octahedral fashion, while Mn(2) is bound to two bridging
thiolates and one terminal thiolate ligand. Its distorted coordina-
tion sphere is completed by one molecule of THF. The
L-Mn-L angles around Mn(2) range from 82.04(7)° (S(1)-
Mn(2)-S(2)) to 141.94(9)° (S(2)-Mn(2)-S(3)), and the Mn-S
distances to the bridging thiolates are longer than those found
in 1, 2, and 4.
with one molecule of the trisulfane tBu3Si-SSS-SitBu3 (Figure
5
; selected bond lengths and angles in the corresponding figure
j
caption), in the trigonal space group R3. The complex anion is
situated on a 3-fold rotational axis in the crystal, with the result
that one-third of the molecule is contained in the asymmetric
unit. The core of the structure consists of two manganese atoms
bridged by three thiolate ligands. The Mn-S distances for the
bridging thiolates are in the same range as those observed for
1. The Mn-S bond to the terminal thiolate, however, is quite
short (2.269(5) Å). Moreover, the Mn-S-Si angle is strictly
linear, since the Mn-S and S-Si bonds lie on the 3-fold
rotational axis. The thermal ellipsoid of S2 (from the terminally
bound thiolate) is fairly small, indicating that the Si-S-Mn
unit does not deviate from linearity. This is significant, because
there are a very limited number of transition-metal complexes
The Mn(2)-S(3)-Si(3) unit in 3 is not linear, but the
terminally bound thiolate ligand features a quite large angle
27
of silyl or alkyl chalcogenolates with linear coordination. It
(
130.9(2)°). The Mn(2)-S(3) bond length is 2.349(2) Å; it is
has been postulated in the literature that chalcogenolate ligands
can act as six-electron donors (analogous to Cp) by donating
nearly 0.1 Å longer than the terminal Mn-S bond for the
(
26) Cambridge Structural Database (CSD, Version 5.29 with three
updates, January 2008; Allen, 2002). Allen, F. H. Acta Crystallogr., Sect.
B 2002, B58, 380.
(27) Medina, I.; Jacobsen, H.; Mague, J. T.; Fink, M. J. Inorg. Chem.
2006, 45, 8844.

Manganese Complexes with Supersilyl Thiolate Ligands
Organometallics, Vol. 27, No. 13, 2008 3277
The NMR spectra were recorded on a Bruker AM 250, a Bruker
DPX 250, a Bruker Avance 300, and a Bruker Avance 400
2
9
spectrometer. The Si NMR spectra were recorded using the
INEPT pulse sequence with empirically optimized parameters for
polarization transfer from the tBu substituents. Mass spectra were
recorded with a VG PLATFORM II mass spectrometer.
Synthesis of 1. To a solution of [Mn(CO)
mmol) in 15 mL of THF was added Na(THF)
.95 mmol) in one portion. The orange solution quickly became
5
Br] (128 mg, 0.46
2
SSitBu (378 mg,
3
0
cloudy. After 3 h, volatiles were removed in vacuo and the brown
residue was extracted with pentane (10 mL). The extract was filtered
over diatomaceous earth on a frit. The filter cake was washed with
pentane (2 × 5 mL). Slow concentration of the filtrate led to the
deposition of the product as a microcrystalline solid. X-ray-quality
crystals were obtained by recrystallization from pentane at -20
-
1
°
2
C
8
C. Yield: 167 mg (45%). IR (CH
035 (m), 2001 (s), 1972 (m), 1925 (m). H NMR (250.1 MHz,
): δ 1.38 (s, 54H, tBu), δ 3.45 (br, 8H, OCH ), δ 1.40 (br,
): δ 25.3 (CCH ), δ 31.7
), δ 222.5 (CO), THF not observed. Si NMR (79.5 MHz,
2 2
Cl , cm ): V˜ (CO absorptions)
Figure 5. Plot of tBu
ing scheme. H atoms have been omitted for clarity. Selected bond
3
Si-SSS-SitBu
3
showing the atomic number-
1
6
D
H, CH
6
2
lengths (Å) and angles (deg): Si(3)-C(3A) ) 1.928(10), Si(3)-C(3B)
1
3
2
). C NMR (62.9 MHz, C
6
D
6
3
)
1.928(11), Si(3)-C(3) ) 1.928(10), Si(3)-S(3) ) 2.225(17),
2
9
(
CCH
3
Si(4)-C(4A) ) 1.894(16), Si(4)-C(4B) ) 1.894(17), Si(4)-C(4)
1.895(16), Si(4)-S(5) ) 2.208(16), S(3)-S(4) ) 1.932(16),
+
C
(
(
8
6 6
D ): δ 29.5. MS (ESI ): m/z (%) 797.4 (100) 798.4 (60) 799.5
)
+ +
40) [M + H] , calcd for [M + H] 797.3 (100) 798.3 (52) 799.3
30). Anal. Calcd for C36 70MnNaO Si (797.17): C, 54.24; H,
.85. Found: C, 52.77; H, 8.88.
Synthesis of 2. A mixture of 1 (97 mg, 0.12 mmol),
Mn(CO) Br] (71 mg, 0.25 mmol), and 4 mL of benzene was stirred
S(4)-S(5))1.904(19),S(4)-S(3)-Si(3))107.1(7),S(5)-S(4)-S(3)
H
6
S
2
2
)
95.1(11), S(4)-S(5)-Si(4) ) 102.7(8).
1
7,28
two σ and four π electrons.
The prerequisite for this type
[
5
of donation, however, is linear coordination, which is rarely
observed. In the case of 4, the significant steric hindrance of
the supersilyl groups enforces such linear coordination, thus
allowing for six-electron donation.
for 4 days at ambient temperature. After filtration, crystals of 2
were grown from the benzene solution at ambient temperature. The
IR spectrum of the mother liquor revealed bands which could be
assigned to [Mn
2
2
(CO)10] (IR (benzene, cm- ): V˜ (CO absorptions)
1
046 (m), 2014 (s), 1982 (w)). Yield: 51 mg (52%). Selected data
-1
Summary and Conclusion
for 2: IR (KBr, cm ): V˜ (CO absorptions) 2038 (m), 1997 (s),
964 (m), 1946 (m). Anal. Calcd for C32 BrO Si (836.91):
C, 45.92; H, 7.47. Found: C, 46.33; H, 6.95.
X-ray-quality crystals of 2 were obtained from 1 (44 mg, 0.06
1
H
62Mn
2
S
5 2
2
In summary, it has been shown that the manganese carbonyl
thiolates 1-4 can be prepared from the precursors
Na(THF)2SSitBu3 and [Mn(CO)5Br]. When [Mn(CO)5Br] is
treated with 1 or 2 equiv of Na(THF)2SSitBu3, the 1:2
substitution product 1 is formed quickly (Scheme 3). When an
additional 1 equiv of [Mn(CO)5Br] is present (as in the 1:1
reaction) or is subsequently added to the reaction mixture, the
dinuclear Mn(I)Mn(II) complex 2 can be isolated along with
5
mmol) and [Mn(CO) Br] (32 mg, 0.12 mmol) in benzene at ambient
temperature.
Synthesis of 3. To a solution of [Mn(CO)
mmol) in 15 mL of THF was added Na(THF)
.51 mmol) in one portion. The orange solution quickly became
5
Br] (143 mg, 0.53
2
SSitBu (205 mg,
3
0
cloudy. After 4 h, no unreacted thiolate could be observed in the
NMR spectra of the reaction mixture, and signals consistent with
[
Mn2(CO)10] (Scheme 3). Treatment of 2 with 1 equiv of
1
13
Na(THF)2SSitBu3 gives the mixed-valence dinuclear manganese
thiolate complex 3. The formation of 4, however, can be
explained by the reaction of 3 with a further 1 equiv of
NaSSitBu3 (Scheme 3). The complex anion of 4 contains a
terminal thiolate ligand with a linear Mn-S-Si unit. The
prerequisite for six-electron donation (two σ and four π
electrons) is thus fulfilled, clearing the way for comparisons to
6 6
a substitution product had grown (C D , H NMR δ 1.32; C NMR
2
9
δ 31.5, 26.0; Si NMR δ 31.4). Volatiles were removed in vacuo,
and the brown residue was extracted with pentane (10 mL). The
extract was filtered over diatomaceous earth on a frit. The filter
cake was washed with pentane (2 × 5 mL). After standing at -20
°C for several weeks, X-ray-quality crystals of 3 could be obtained
from a pentane solution. Yield: 50 mg (0.05 mmol, 29%). IR
-
-1
the analogous six-electron donor Cp . It is interesting to note
(hexane, cm ): V˜ (CO absorptions) 2037 (m), 1992 (s), 1949 (m).
1
-
that the supersilyl thiolates 2-4 represent the first structurally
characterized mixed-valence Mn(I)Mn(II) carbonyl thiolate
complexes.
H NMR (C
6
D
6
, 250.1 MHz): 1.40 (s, tBu). MS (ESI ): m/z (%)
-
9
87.9 (100), 988.9 (60), 988.9 (66), 990.0 (51), 991.0 (21) [M] ,
-
calcd for [M] 987.4 (100), 988.4 (66), 989.4 (46), 990.4 (20).
Anal. Calcd for C44 Si (988.50): C, 53.46; H, 9.08.
Found: C, 51.13; H, 8.80.
Reaction of 2 with Na(THF) SSitBu . To a solution of 2 (98
H89Mn
2
O
5
S
3
3
Experimental Section
2
3
mg, 0.12 mmol) in 5 mL of benzene was added Na(THF)
2 3
SSitBu
General Procedures. All experiments were carried out under
(
95 mg, 0.24 mmol). After filtration the IR spectrum of reaction
dry nitrogen or argon with strict exclusion of air and moisture using
2
9
solution revealed bands which could be assigned to 3. Volatiles
were removed in vacuo, and the red residue was extracted with
THF (5 mL). The THF solution was stirred for 7 days. After the
solvent had been removed in vacuo, an IR spectrum was measured
from the residue. IR (KBr, cm- ): V˜ (CO absorptions) 2045 (m),
standard Schlenk techniques or a glovebox. Na(THF)
2
SitBu
3
and
2
Na(THF) SSitBu were prepared according to literature procedures.
2 3
The solvents (benzene, toluene, tetrahydrofuran) were distilled from
sodium/benzophenone prior to use.
1
2
2010 (m), 1980 (s), 1960 (s). Anal. Calcd for C63H129Mn NaO
S Si
9 3 3
(
28) Hirsekorn, K. F.; Veige, A. S.; Marshak, M. P.; Koldobskaya, Y.;
Wolczanski, P. T.; Cundari, T. R.; Lobkovsky, E. B. J. Am. Chem. Soc.
005, 127, 4809.
29) Lerner, H.-W. Coord. Chem. ReV. 2005, 249, 781.
(
1344.01): C, 56.30; H, 9.67. Found: C, 54.76; H, 8.93.
Formation of 4. When a reaction solution of [Mn(CO)
5
Br] with
2
(
2 3
Na(THF) SSitBu in 1:2 stoichiometry was left to stand for several

3
278 Organometallics, Vol. 27, No. 13, 2008
Kückmann et al.
Table 2. Crystal Data and Structure Refinement Details for 1-3 and 4 · tBu3Si-SSS-SitBu3
1
2
3
4 · tBu3Si-SSS-SitBu3
empirical formula
color
shape
C36H70MnNaO6S2Si2
light brown
needle
C32H62BrMn2O5S2Si2
orange
plate
C44H89Mn2O5S3Si3
dark red
block
C99H210Mn2NaO9S7Si6
orange
plate
fw
797.15
836.91
988.48
2070.50
cryst syst
space group
a, Å
b, Å
c, Å
monoclinic
P21/c
monoclinic
P21/n
monoclinic
C2/c
trigonal
R3
j
23.1442(11)
17.4691(6)
23.2056(12)
104.506(4)
9083.1(7)
8
1.166
0.482
3440
8.8106(5)
17.3613(7)
27.1951(16)
92.666(5)
4155.4(4)
4
1.338
1.761
1756
0.23 × 0.22 × 0.11
2.35-26.00
-10 e h e 10,
-21 e k e 21,
-30 e l e 33
50 736
24.9621(12)
13.3952(4)
34.7460(18)
109.554(4)
10 948.0(8)
8
1.199
0.679
4264
0.33 × 0.30 × 0.27
2.31-26.25
-30 e h e 30,
-16 e k e 16,
-42 e l e 42
88 081
14.6380(5)
14.6380(5)
101.570(7)
90
18 847.7(16)
6
1.095
0.423
6798
0.27 × 0.25 × 0.14
2.13-25.01
-17 e h e 17,
-17 e k e 17,
-120 e l e 120
70 191
ꢀ
, deg
V, Å
3
Z
3
calcd density, Mg/m
abs coeff µ(Mo KR), mm
F(000)
cryst size, mm
θ range, deg
index ranges
-
1
3
0.31 × 0.12 × 0.12
2.72-25.64
-28 e h e 28,
-
20 e k e 21,
27 e l e 28
-
no. of rflns collected
no. of indep rflns
R(int)
78 803
17 283
0.1118
8095
0.0966
10 102
0.1224
7364
0.1004
Tmax, Tmin
no. of data/restraints/params
goodness of fit on F
0.9444, 0.8649
17 283/0/867
0.957
0.8299, 0.6875
8095/0/408
0.928
0.8379, 0.8070
10 102/126/508
1.199
0.9431, 0.8942
7364/0/392
1.036
2
final R indices (I > 2σ(I)): R1, wR2
0.0566, 0.1214
0.0884, 0.1345
0.579/-0.375
0.0405, 0.0807
0.0680, 0.0881
0.468/-0.443
0.1296, 0.2596
0.1388, 0.2642
1.139/-1.065
0.1075, 0.2847
0.1766, 0.3175
1.077/-0.873
R indices (all data): R1, wR2
-
3
peak/hole, e Å
weeks, crystals of the composition Na(THF)
6
[(CO)
4
Mn(µ-
parameters using a riding model. CCDC reference numbers: 678303
SSitBu Mn(SSitBu )] (4) and tBu Si-SSS-SitBu
isolated. Due to the low yield of these species, no further
characterization could be undertaken.
3
)
3
3
3
3
could be
(1), 678305 (2), 678304 (3), and 678302 (4 · tBu Si-SSS-SitBu ).
Table 2 gives crystal data and structure refinement details for 1-4.
3
3
X-ray Structure Determination. Data collection: Stoe-IPDS-
II diffractometer, graphite-monochromated Mo KR radiation; T )
Acknowledgment. We are grateful to the University of
Frankfurt for financial funding and the Chemetall GmbH for
a gift of tert-butyllithium.
30
1
73 K, empirical absorption correction using MULABS, structure
31
solution by direct methods. Structure refinement: full-matrix least
2
32
squares on F with SHELXL-97. Hydrogen atoms were placed
Supporting Information Available: CIF files giving X-ray
parameters, atomic coordinates and thermal parameters, and bond
distances and angles for 1-4. This material is available free of
charge via the Internet at http://pubs.acs.org.
on ideal positions and refined with fixed isotropic displacement
(
(
(
30) Blessing, R. H. Acta Crystallogr., Sect. A 1995, 51, 33.
31) Sheldrick, G. M. Acta Crystallogr., Sect. A 1990, 46, 467.
32) Sheldrick, G. M. SHELXL-97, A Program for the Refinement of
Crystal Structures; University of G o¨ ttingen, G o¨ ttingen, Germany, 1997.
OM800211K