Reactions of [(CO)3Mn(η5-Thi)]+ (Thi = thiophene or 2,5-dimethylthiophene) with nucleophiles

Article abstract of DOI:10.1021/om950584r

The η⁵-thiophene complexes, [(CO)₃Mn(η⁵-T)]⁺ (1) and [(CO)₃Mn(η⁵-2,5-Me₂T)]⁺ (2), react with LiCuR₂ (R = Me or Ph) by adding R^- to the sulfur ato

Full text of DOI:10.1021/om950584r

Organometallics 1996, 15, 325-331
325
Rea ction s of [(CO)3Mn (η5-Th i)]+ (Th i ) Th iop h en e or
2,5-Dim eth ylth iop h en e) w ith Nu cleop h iles
J iabi Chen,† Victor G. Young, J r.,‡ and Robert J . Angelici*
Department of Chemistry and Ames Laboratory, Iowa State University, Ames, Iowa 50011
Received J uly 27, 1995X
The η5-thiophene complexes, [(CO)3Mn(η5-T)]+ (1) and [(CO)3Mn(η5-2,5-Me2T)]+ (2), react
with LiCuR2 (R ) Me or Ph) by adding R- to the sulfur atom of the thiophene, which gives
the η4-thiophene complexes, (CO)3Mn(η4-T‚R) and (CO)3Mn(η4-2,5-Me2T‚R). An X-ray study
of (CO)3Mn(η4-T‚C6H5) (6) shows the η4-T‚C6H5 ligand to be coordinated to the manganese
through the four thiophene carbon atoms, while the sulfur bearing the phenyl group is bent
away from the metal. The structure of 6 supports previous suggestions that the sulfur in
η5-thiophene complexes is an electrophilic center. Reactions of 1 or 2 with RS-, CH3O-, or
-CH(CO2CH3)2 nucleophiles result in the displacement of thiophene with the formation of
[(CO)4Mn(µ-SR)]2 or Mn2(CO)10. The structure of [(CO)4Mn(µ-SC6H4CH3-p)]2 (9), established
by X-ray studies, is also reported.
In tr od u ction
(CO)10. Thus, the methyl groups prevented H- addition
at the 2- and 5-positions.
Reactions of [(η6-arene)Mn(CO)3]+ complexes with
In the present report, we extend our studies of the
[(η5-thiophene)Mn(CO)3]+ complexes to reactions with
carbon, sulfur, and oxygen nucleophiles. They lead to
quite different products, depending on the nucleophile.
We also report improved syntheses of the complexes [(η5-
Thi)Mn(CO)3]+, where Thi ) thiophene (T) or 2,5-
dimethylthiophene (2,5-Me2T).
nucleophiles lead1 to cyclohexadienyl products (eq 1).
Exp er im en ta l Section
Oxidations2 of these products give the free substituted
arenes Ar-Nuc. Such reactions were particularly suc-
cessful for carbon nucleophiles such as LiPh, LiMe,
Grignard reagents, and stabilized enolates. Earlier, we
showed3,4 that the analogous thiophene complexes [(η5-
T)Mn(CO)3]+ undergo attack at the 2-position by hy-
Gen er a l P r oced u r es. All reactions were carried out under
a dry, oxygen-free N2 atmosphere using standard Schlenk
techniques. All solvents employed were reagent grade and
were dried by refluxing over appropriate drying agents and
stored over 4-Å molecular sieves under an N2 atmosphere until
used. Tetrahydrofuran (THF) and diethyl ether (Et2O) were
distilled from sodium benzophenone ketyl, while hexanes and
CH2Cl2 were distilled from CaH2. CH3NO2 was deoxygenated
in vacuo and dried over 4-Å molecular sieves. The neutral
Al2O3 (Brockmann, activity I, 80-100 mesh) used for chroma-
tography was deoxygenated under high vacuum at room
temperature for 16 h, deactivated with 5% (w/w) nitrogen-
saturated water, and stored under nitrogen, while the neutral
SiO2 (5 × 0143U-1, 60-200 mesh) was deoxygenated under
high vacuum at room temperature for 12 h. AgBF4, thiophene,
2,5-dimethylthiophene, CuI, CH3Li, C6H5Li, NaSCH3, NaOCH3,
CH2(COOCH3)2, and NaH were purchased from Aldrich Chemi-
-
dride nucleophiles such as BH4-, HFe(CO)4 and
-
HW(CO)5 (eq 2). The nucleophiles CN- and PR3
6
cal Co. Mn(CO)5Br5 and NaSC6H4CH3 were prepared by
reacted similarly. For the analogous 2-methylthiophene
complex [(η5-2-MeT)Mn(CO)3]+, hydride nucleophiles
added at the 5-position. When using a 2,5-disubstituted
thiophene such as [(η5-2,5-Me2T)Mn(CO)3]+, the only
product isolated from the reaction with BH4- was Mn2-
literature methods.
Elemental analyses were performed by Galbraith Labora-
tory, Inc., or National Chemical Consulting, Inc. The IR
spectra were recorded on a Nicolet 710 FT-IR spectrophotom-
1
eter. All H NMR spectra were recorded at ambient temper-
ature on samples in CDCl3 solution with CHCl3 as the internal
reference, or in CD3NO2 solution with CH3NO2 as the internal
reference, using a Nicolet NT-300 spectrometer. Electron
ionization mass spectra (EIMS) and chemical ionization mass
spectra (CIMS) were run on a Finnigan 4000 spectrometer at
70 eV. Melting points were recorded in sealed nitrogen-filled
capillaries and are uncorrected.
† Permanent address: Shanghai Institute of Organic Chemistry,
Chinese Academy of Sciences, Shanghai, PRC.
‡ Iowa State University Molecular Structure Laboratory. Current
address: University of Minnesota, Minneapolis, MN 55455.
X Abstract published in Advance ACS Abstracts, November 15, 1995.
(1) (a) Kane-Maguire, L. A. P.; Honig, E. D.; Sweigart, D. A. Chem.
Rev. 1984, 84, 525. (b) Lee, T.-Y.; Kang, Y. K.; Chung, Y. K.; Pike, R.
D.; Sweigart, D. A. Inorg. Chim. Acta 1993, 214, 125.
(2) Pike, R. D.; Sweigart, D. A. Synlett 1990, 565.
P r ep a r a tion of [(CO)3Mn (η5-T)]BF 4 (T ) Th iop h en e)
(1). To a solution of Mn(CO)5Br (1.0 g, 3.6 mmol) in CH2Cl2
(3) Lesch, D. A.; Richardson, J . W., J r.; J acobson, R. A.; Angelici,
R. J . J . Am. Chem. Soc. 1984, 106, 2901.
(4) Huckett, S. C.; Sauer, N. N.; Angelici, R. J . Organometallics
1987, 6, 591.
(5) Quick, M. H.; Angelici, R. J . Inorg. Synth. 1979, 19, 160.
(6) Spies, G. H.; Angelici, R. J . Organometallics 1987, 6, 1897.
0276-7333/96/2315-0325$12.00/0 © 1996 American Chemical Society

326 Organometallics, Vol. 15, No. 1, 1996
Chen et al.
(15 mL) was added an equimolar amount of AgBF4 (0.71 g,
3.6 mmol). The mixture was refluxed in the dark for 0.5 h to
give a red solution containing a gray-white solid, which was
cooled to room temperature. To this was added thiophene (1.0
mL, 1.05 g, 12.4 mmol), and then the mixture was refluxed
for 1 h (in the dark). After vacuum removal of the solvent,
the resulting yellow solid residue was dissolved in CH3NO2,
and the solution was filtered to remove the insoluble gray-
white solid. The filtrate was reduced in vacuo to ca. 2 mL, to
which was added 90 mL of CH2Cl2 to precipitate the product.
The yellow product was filtered and washed with CH2Cl2 and
then dried under vacuum for 1 h to give 0.75 g (67%, based on
Mn(CO)5Br) of yellow powder 1. IR (CH3NO2) ν(CO): 2077
orange-red crystalline 4. 5: mp 98-100 °C (dec). IR (CH2-
Cl2) ν(CO): 1987 vs, 1896 vs br cm-1 1H NMR (CDCl3): 4.84
.
(s, 2 H), 1.90 (s, 3 H), 1.65 (s, 6 H). MS (CI): m/ e 267 (M+
H). Anal. Calcd for 10H11O3SMn: C, 45.12; H, 4.17.
+
C
Found: C, 45.16; H, 3.66. 4 was identified by its melting point
and IR spectrum.
Rea ction of 1 w ith LiCu P h 2 To Give (CO)3Mn (η4-
T‚C6H5) (6) a n d 4. To a suspension of CuI (0.246 g, 1.29
mmol) in THF (20 mL) was added 1.60 mL of 1.8 M (2.75
mmol) LiC6H5 at -10 °C. The solution turned dark yellow and
the solid CuI dissolved. After 10 min of stirring at -5 to 0
°C, the resulting solution of LiCuPh27 was added to a solution
of 1 (0.400 g, 1.29 mmol) dissolved in THF (30 mL) at -60 °C.
The reaction solution rapidly turned dark yellow and was
stirred initially at -60 °C and then allowed to warm to 15 °C
over 12 h. After the solution was evaporated to dryness under
vacuum, the dark green-yellow residue was chromatographed
on SiO2 (neutral) with hexanes/CH2Cl2 (3:1) as the eluant. The
yellow band that eluted first was collected, and then the red
band was eluted with CH2Cl2/Et2O (4:1). After vacuum
removal of the solvents from the preceding two eluates, the
residues were recrystallized from hexanes/CH2Cl2 at -80 °C.
From the first fraction, 0.145 g (37%, based on 1) of 6 was
obtained as yellow crystals (mp 106-107 °C (dec)). IR (CH2-
vs, 2060 m, 2012 m cm-1 1H NMR (CD3NO2): δ 6.87 (d, 2 H),
.
6.78 (d, 2 H). MS: m/ e 307 (M+ - 2 H). Anal. Calcd for
C7H4O3BF4SMn: C, 27.13; H, 3.30. Found: C, 26.78; H, 3.35.
P r ep a r a tion of [(CO)3Mn (η5-2,5-Me2T)]BF 4 (2). To a
solution of Mn(CO)5Br (2.0 g, 7.28 mmol) in CH2Cl2 (40 mL)
was added 1.50 g (7.70 mmol) of AgBF4. The mixture was
refluxed in the dark for 30-45 min and then allowed to cool
to room temperature. To this mixture was added 1.5 mL (1.48
g, 13.2 mmol) of 2,5-Me2T. The mixture was refluxed for 1 h
(in the dark). Further treatment of the resulting mixture as
described earlier for the preparation of 1 gave 1.74 g (71%,
based on Mn(CO)5Br) of yellow powder 2. IR (CH3NO2)
Cl2) ν(CO): 1996 vs, 1907 vs br cm-1
.
1H NMR (CDCl3): δ
ν(CO): 2097 m, 2072 vs, 2009 vs cm-1 1H NMR (CDCl3): δ
.
7.54-7.01 (m, 5 H), 5.28 (s, 2 H), 2.72 (s, 2 H). MS: m/ e 300
(M+). Anal. Calcd for C13H9O3SMn: C, 52.01; H, 3.02.
Found: C, 52.31; H, 2.98. From the second fraction, 0.105 g
(28%, based on 1) of orange-red crystalline 4 was obtained; it
was identified by its melting point and IR spectrum.
6.41 (s, 2 H), 2.53 (s, 6 H). MS: m/ e 251 (M+ - BF4), 250 (M+
- BF4 - H). Anal. Calcd for C9H8O3BF4SMn: C, 31.99; H,
2.39. Found: C, 31.82; H, 1.98.
Rea ction of 1 w ith LiCu Me2 To Give (CO)3Mn (η4-
T‚CH3) (3) a n d [(CO)4Mn I]2 (4). To a suspension of CuI
(0.123 g, 0.65 mmol) in THF (20 mL) at 0 °C was added 0.90
mL (1.37 mmol, 1.5 M solution) of LiCH3 with stirring. The
reaction solution was stirred at 0 °C for 10 min. The resulting
LiCuMe27 solution was added to a solution of [(CO)3Mn(η5-T)]-
BF4 (1) (0.200 g, 0.645 mmol) in 30 mL of THF at -60 °C. The
solution turned red immediately. The reaction solution was
stirred while warming from -60 to 15 °C over a 12-h period;
the resulting dark-red solution was evaporated under vacuum
to dryness, and the dark residue was chromatographed on SiO2
(neutral) with hexanes/CH2Cl2 (15:1) as the eluant. The light
yellow band that eluted first was collected, and then the red
band was eluted with CH2Cl2/Et2O (2:1). After vacuum
removal of the solvents from the preceding two eluates, the
residues were recrystallized from hexanes/CH2Cl2 at -80 °C.
From the first fraction, 0.085 g (55%, based on 1) of light yellow
crystals of 3 was obtained (mp 86-88 °C (dec)). IR (CH2Cl2)
Rea ction of 2 w ith LiCu P h 2 To Give (CO)3Mn (η4-2,5-
Me2T‚C6H5) (7) a n d 4. This reaction was conducted as
described earlier for the reaction of 1 with LiCuPh2. A solution
of LiCuPh2 prepared by the reaction of CuI (0.169 g, 0.887
mmol) with LiC6H5 (0.99 mL of 1.8 M solution, 1.77 mmol)
was added to a solution of 2 (0.300 g, 0.888 mmol) dissolved
in THF (30 mL) at -60 °C. After being stirred for 10 h while
being warmed to 0 °C, the solution was evaporated to dryness
under vacuum. Further treatment of the residue as described
for the reaction of 1 with LiCuPh2 gave 0.095 g (33%, based
on 2) of yellow crystalline 7 and 0.070 g (27%, based on 2) of
4. 7: mp 148-149 °C (dec). IR (CH2Cl2) ν(CO): 1989 vs, 1899
vs br cm-1 1H NMR (CDCl3): δ 7.80 (m, 1 H), 7.48 (m, 2 H),
.
7.15 (m, 1 H), 4.95 (s, 2 H), 1.69 (s, 6 H). MS (CI): m/ e 329
(M+ + H). Anal. Calcd for C15H13O3SMn: C, 54.88; H, 3.99.
Found: C, 54.55, H, 4.08. Compound 4 was identified by its
melting point and IR spectrum.
ν(CO): 1995 vs, 1904 vs br cm-1 1H NMR (CDCl3): δ 5.28 (s,
.
Rea ction of 1 w ith Na SCH3 To Give [(CO)4Mn (SCH3)]2
(8). To a solution of 1 (0.300 g, 0.968 mmol) dissolved in 40
mL of THF at 0 °C was added 0.073 g (1.04 mmol) of NaSCH3.
The mixture was stirred at room temperature for 48 h. The
resulting light-yellow solution was evaporated under vacuum
to dryness, and the residue was chromatographed on Al2O3
(neutral) with hexanes/CH2Cl2 (10:1) as the eluant. A yellow
band was eluted and collected. After removal of the solvent,
the resulting yellow powder was recrystallized from hexanes/
CH2Cl2 at -80 °C to give 0.112 g (54%, based on 1) of golden-
yellow crystals of 89 (mp 112-114 °C (dec)). IR (CH2Cl2)
2 H), 2.40 (s, 2 H), 1.85 (s, 3 H). MS: m/ e 238 (M+), 223 (M+
- CH3), 167 (M+ - CH3 - 2CO), 139 (M+ - CH3 - 3CO). Anal.
Calcd for C8H7O3SMn: C, 40.35; H, 2.96. Found: C, 39.09;
H, 2.88. From the second fraction, 0.045 g (24%, based on 1)
of orange-red crystals of 48 was obtained (mp 165 °C (dec)).
IR (CH2Cl2) ν(CO): 2088 s, 2034 vs, 2006 s, 1973 s cm-1. MS:
m/ e 558 (M+). Anal. Calcd for C8O8I2Mn2: C, 16.35. Found:
C, 16.61.
Rea ction of 2 w ith LiCu Me2 To Give (CO)3Mn (η4-2,5-
Me2T‚CH3) (5) a n d 4. As described for the reaction of 1 with
LiCuMe2, 0.300 g (0.888 mmol) of 2 in THF (40 mL) at -60 °C
was treated with fresh LiCuMe2 [prepared by the reaction of
CuI (0.169 g, 0.887 mmol) with LiCH3 (1.28 mL of 1.5 M
solution, 1.78 mmol)].7 The mixture was allowed to warm to
-5 °C over a 10-h period, during which time the light-yellow
solution turned to dark red. Further treatment of the resulting
solution in a manner similar to that described earlier for the
reaction of 1 with LiCuMe2 yielded 0.115 g (49%, based on 2)
of light-yellow crystals of 5 and 0.080 g (31%, based on 2) of
ν(CO): 2072 s, 2019 vs, 2000 w, 1960 s cm-1
.
1H NMR
(CDCl3): δ 1.99 (s, 6 H). MS: m/ e 428 (M+). Anal. Calcd for
C
10H6O8S2Mn2: C, 28.05; H, 1.41. Found: C, 28.19; H, 1.67.
Rea ction of 2 w ith Na SCH3 To Give 8. Following the
procedure described for the reaction of 1 with NaSCH3, the
reaction of 2 (0.300 g, 0.888 mmol) with NaSCH3 (0.065 g,
0.927 mmol) gave 0.095 g (50%, based on 2) of golden-yellow
crystals of 8, which were identified by their melting point and
IR and 1H NMR spectra.
Rea ction of 1 w ith Na SC6H4CH3-p To Give [(CO)4Mn -
(SC6H4CH3-p]2 (9). To a solution of 1 (0.300 g, 0.968 mmol)
(7) (a) Caldarelli, J . L.; Wagner, L. E.; White, P. S.; Templeton, J .
L. J . Am. Chem. Soc. 1994, 116, 2878 (see footnote 34). (b) Lipshutz,
B. H. In Organometallics in Synthesis; Schlosser, M., Ed.; J ohn Wiley
& Sons: New York 1994; p 283.
(9) Treichel, P. M.; Morris, J . H.; Stone, F. G. A. J . Chem. Soc. 1963,
(8) Abel, E. W.; Wilkinson, G. J . Chem. Soc. 1959, 1501.
720.

Reactions of [(CO)3Mn(η5-Thi)]+ with Nucleophiles
Organometallics, Vol. 15, No. 1, 1996 327
Ta ble 1. Cr ysta l a n d Da ta Collection P a r a m eter s
for (CO)3Mn (η4-T‚C6H5) (6) a n d
dissolved in THF (30 mL) at 0 °C was added 0.146 g (0.999
mmol) of NaSC6H4CH3-p. The mixture was stirred at room
temperature for 24 h, during which time the solution gradually
turned from light yellow to yellow green. After the solution
was evaporated to dryness under vacuum, the residue was
chromatographed on Al2O3 (neutral) with hexanes/CH2Cl2 (10:
1) as the eluant. The yellow band was collected. After vacuum
removal of the solvent, the residue was recrystallized from
hexanes/CH2Cl2 at -80 °C to give 0.160 g (57%, based on 1) of
9 as orange-yellow crystals (mp 108-110 °C (dec)). IR
[(CO)4Mn (SC6H4CH3-p)]2 (9)
6
9
formula
fw
C13H9MnO3S
300.2
C33H21Mn3O12S3
870.5
cryst system
space group
a ( Å)
b ( Å)
c ( Å)
monoclinic
P21/n
monoclinic
P21/c
10.240(2)
9.281(2)
37.924(4)
90.38(2)
3604.0(4)
4
9.397(4)
14.341(3)
9.649(2)
105.57(2)
1252.6(2)
4
(hexane) ν(CO): 2077 s, 2020 vs, 2004 w, 1968 s cm-1
.
1H
â (deg)
V (Å3)
Z
NMR (CDCl3): δ 7.81-7.11 (m, 8 H), 2.31 (s, 6 H). MS: m/ e
580 (M+). Anal. Calcd for C22H14O8S2Mn2: C, 45.53; H, 2.43.
Found: C, 45.57; H, 2.46.
Rea ction of 2 w ith Na SC6H4CH3-p To Give 9. The
reaction of 2 (0.135 g, 0.399 mmol) with NaSC6H4CH3-p (0.058
g, 0.397 mmol) and subsequent treatment of the product
solution were performed in a manner similar to that described
for the reaction of 1 with NaSC6H4CH3-p to give 0.060 g (50%,
based on 2) of 9, which was identified by its melting point and
IR and 1H NMR spectra.
Rea ction of 1 w ith Na OCH3 To Give Mn 2(CO)10 (10).
A 0.300-g (0.968 mmol) sample of 1 was dissolved in THF (40
mL). To this solution was added 0.055 g (1.02 mmol) of
NaOCH3. The mixture was stirred at room temperature for
24 h. The resulting light-yellow solution was evaporated to
dryness, and the residue was chromatographed on Al2O3
(neutral) with hexanes/CH2Cl2 (15:1) as the eluant. A yellow
band eluted. The solvent was removed from it, and the yellow
residue was recrystallized from hexanes/CH2Cl2 at -80 °C to
give 0.085 g (45%, based on 1) of yellow crystalline 10, which
was identified as Mn2(CO)10 by comparison of its melting point
and IR spectrum with that of an authentic sample of Mn2(CO)10
[mp 150-152 °C (dec); IR (CH2Cl2) ν(CO) 2046 s, 2011vs br,
1979 s cm-1].
d
calc (Mg/m3)
1.592
1.604
crystal size (mm)
0.38 × 0.18 × 0.13
0.45 × 0.12 × 0.08
µ, (mm-1
)
10.109
1.270
diffractometer used Siemens P4RA
radiation
Enraf-Nonius CAD4
Mo KR
Cu KR
(λ ) 1.541 78Å)
213
(λ ) 0.710 73 Å)
298
temp (K)
scan method
data collection
range, 2θ (deg)
2θ-θ
ω-2θ
4.0-115.0
4.0-50.0°
no. of data collected 3607
8975
no. of unique data
no. of data with
Fo > 4.0 σ (F)
no. of parameters
refined
1683 (Rint ) 0.0216) 6329 (Rint ) 0.0267)
1429
4115
185
475
transmission
factors: min/max
Ra
0.53/0.83
0.55/0.85
0.0328
0.0400
1.45
0.29
0.0
0.0404
0.0493
1.02
0.46
0.0
b
Rw
goodness-of-fitc
largest peak (e/Å3)
largest shift/eds.
final cycle
Rea ction of 2 w ith Na OCH3 To Give 10. As described
for the reaction of 1 with NaOCH3, 0.300 g (0.888 mmol) of 2
was treated with NaOCH3 (0.052 g, 0.963 mmol) at room
temperature for 36 h to give 0.090 g (52%, based on 2) of 10,
which was identified by comparison of its melting point and
IR spectrum with those of commercial Mn2(CO)10.
a
b
2
R ) ∑||Fo| - |Fc||/∑|Fo|. Rw ) |∑w(|Fo| - |Fc|)2/∑w|Fo| ]1/2; w
) 1/σ2(|Fo|). c Quality-of-fit ) [∑w(|Fo| - |Fc|)2/(Nobs - Nparameters)]1/2
.
were determined from a subset of intense reflections in the
range of 35.0-50.0° for 2θ. The data collection was conducted
under a cryogenic stream of N2 at 213 °C. An orange crystal
of 9 was mounted on an Enraf-Nonius CAD4 diffractometer
with monochromated Mo KR radiation at 298 °C. Pertinent
data collection and reduction information are given in Table
1.
Lorentz and polarization corrections were applied for 6 and
9. Both were also corrected for decay and for absorption by
using the semiempirical method based on several azimuthal
scans.
The space group for 6 was determined to be P21/n on the
basis of systematic absences and intensity statistics. All non-
hydrogen atoms were placed directly from the E-map using
direct methods. All non-hydrogen atoms were refined with
anisotropic displacement parameters. Hydrogen atoms were
refined as riding atoms. The final positional and isotropic
displacement parameters are given in Table 2. Bond distances
and selected angles are presented in Table 3.
The solution and refinement of 9 in space group P21/c was
performed in the same manner as for 6. The final positional
and isotropic displacement parameters are given in Table 4.
Selected bond lengths and angles are presented in Table 5.
Both 6 and 9 were solved and refined using SHELXTL-Plus.11
Rea ction of 1 w ith Na CH(CO2CH3)2 To Give 10. To a
suspension of NaH (0.040 g, 1.67 mmol) [60% dispersion in
mineral oil, washed with hexanes (5 × 10 mL) before use] in
THF (15 mL) at room temperature was added dropwise 0.20
g (1.5 mmol) of dimethyl malonate (CH2(CO2CH3)2) (in 5 mL
of THF) over a period of 5-8 min; H2 gas evolution was
observed. After being stirred for 10 min at room temperature,
10
the solution of NaCH(CO2CH3)2 was added to a solution of
0.400 g (1.29 mmol) of 1 dissolved in THF (50 mL) at -60 °C
with stirring. The solution immediately turned from yellow
to orange red. After being stirred while warming to 15 °C over
a 10-h period, the solution was evaporated under vacuum to
dryness, and the residue was chromatographed on Al2O3
(neutral) with hexanes/CH2Cl2 (15:1) as the eluant. The yellow
band was collected, and the solvent was removed. The crude
product was recrystallized from hexanes/CH2Cl2 at -80 °C to
give 0.115 g (46%, based on 1) of 10.
Rea ction of 2 w ith Na CH(CO2CH3)2 To Give 10.
2
(0.350 g, 1.04 mmol) was reacted with NaCH(CO2CH3)2,
prepared by the reaction of NaH (0.029 g, 1.21 mmol) with
CH2(CO2CH3)2 (0.145 g, 1.10 mmol), in a manner similar to
that described for the reaction of 1 with NaCH(CO2CH3)2.
Yellow crystals of 10 (0.098 g, 48% based on 2) were isolated
and identified by their melting point and IR spectrum.
X-r a y Cr ysta l Str u ctu r e Deter m in a tion s of (CO)3Mn -
(η4-T‚C6H5) (6) a n d [(CO)4Mn (SC6H4CH3-p)]2 (9). A light-
yellow needle crystal of 6 was attached to the tip of a glass
fiber and mounted on a Siemens P4RA diffractometer with
monochromated CuKR radiation. High-angle cell constants
Resu lts a n d Discu ssion
Syn th esis of [(CO)3Mn (η5-T)]+ (1) a n d [(CO)3Mn -
(η5-2,5-Me2T)]+ (2). The first reported synthesis12 of
[(CO)3Mn(η5-T)]+ involved the reaction of Mn(CO)5Cl
(11) SHELXTL-PLUS, Siemens Analytical X-ray, Inc., Madison, WI.
(12) Singer, H. J . Organomet. Chem. 1967, 9, 135.
(10) Hegedus, L. S.; Inoue, Y. J . Am. Chem. Soc. 1982, 104, 4917.

328 Organometallics, Vol. 15, No. 1, 1996
Chen et al.
Ta ble 2. Atom ic Coor d in a tes (×104) a n d
Equ iva len t Isotr op ic Disp la cem en t Coefficien ts (Å2
× 103) for (CO)3Mn (η4-T‚C6H5) (6)
Ta ble 4. Atom ic Coor d in a tes (×104) a n d
Equ iva len t Isotr op ic Disp la cem en t Coefficien ts (Å2
× 103) for [(CO)4Mn (SC6H4CH3-p)]2 (9)
a
a
atom
x
y
z
Ueq
atom
x
y
z
Ueq
Mn
S
2179(1)
2130(1)
1187(4)
2166(4)
3581(5)
3621(4)
2462(4)
2752(4)
3018(5)
2976(5)
2697(5)
2431(4)
1367(4)
809(4)
8390(1)
8867(1)
9346(3)
9805(3)
9470(3)
8745(3)
9771(2)
9491(3)
10160(3)
11089(3)
11361(2)
10712(2)
7340(3)
6673(2)
7819(3)
7430(2)
8515(3)
8608(2)
7197(1)
9956(1)
8305(4)
7659(4)
8178(4)
9215(4)
11303(3)
12726(4)
13797(4)
13463(4)
12040(4)
10955(4)
7616(3)
7886(3)
6466(4)
5989(3)
5457(4)
4323(3)
29(1)
35(1)
37(1)
35(1)
32(1)
29(1)
31(1)
41(1)
50(2)
45(2)
43(2)
36(1)
36(1)
58(1)
42(1)
68(1)
44(1)
70(1)
Mn(1)
Mn(2)
S(1)
S(2)
C(1)
O(1)
C(2)
O(2)
C(3)
O(3)
C(4)
O(4)
C(5)
O(5)
C(6)
O(6)
C(7)
3867(1)
3706(1)
2403(1)
5124(1)
2881(5)
2250(4)
4738(5)
5226(4)
2909(5)
2328(4)
5047(5)
5777(4)
2709(5)
2114(4)
4828(6)
5553(4)
4617(6)
5164(4)
2558(6)
1851(5)
1986(4)
1205(5)
804(5)
1150(5)
1897(5)
2323(5)
706(6)
5327(5)
5647(5)
5833(6)
5697(5)
5437(6)
5254(6)
5769(6)
501(1)
1247(1)
1467(5)
2055(4)
-579(5)
-1245(4)
1880(5)
2732(4)
-58(5)
-403(4)
1319(5)
1181(7)
1231(7)
1437(5)
1682(6)
1623(6)
1431(6)
1963(1)
-1596(1)
-46(1)
1828(1)
1449(1)
1802(1)
1438(1)
1451(1)
1227(1)
2196(1)
2420(1)
2139(1)
2330(1)
1807(1)
1796(1)
1075(1)
851(1)
39(1)
41(1)
40(1)
40(1)
51(2)
79(2)
46(2)
66(1)
49(2)
75(2)
49(2)
78(2)
52(2)
84(2)
50(2)
70(1)
54(2)
82(2)
55(2)
87(2)
40(1)
53(2)
61(2)
54(2)
59(2)
51(2)
78(2)
41(1)
56(2)
61(2)
48(2)
62(2)
59(2)
67(2)
40(1)
43(1)
49(2)
76(2)
54(2)
92(2)
51(2)
79(2)
52(2)
79(2)
44(2)
77(2)
87(3)
58(2)
70(2)
65(2)
88(3)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
C(11)
O(11)
C(12)
O(12)
C(13)
O(13)
484(1)
2659(5)
3045(4)
1036(5)
434(4)
2999(5)
3692(4)
3420(5)
4343(4)
-853(5)
-424(5)
-2165(5)
-2496(4)
-2716(5)
-3472(4)
-3063(5)
-3976(4)
-708(5)
143(5)
-314(6)
-1664(6)
-2524(6)
-2055(5)
-2175(6)
1215(5)
315(5)
3493(5)
4338(3)
945(4)
1815(1)
2021(1)
1150(1)
961(1)
125(4)
O(7)
C(8)
O(8)
a
1517(1)
1556(1)
2229(1)
2440(1)
2767(1)
2892(1)
2679(1)
2352(1)
3253(1)
1003(1)
731(1)
395(1)
321(1)
595(1)
936(1)
-53(1)
269(1)
-242(1)
526(1)
687(1)
29(1)
-96(1)
240(1)
220(1)
667(1)
911(1)
-643(1)
-662(1)
-985(2)
-1293(1)
-1269(1)
-949(1)
-1647(1)
Equivalent isotropic U is defined as one-third of the trace of
the orthogonalized Uij tensor.
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
Mn(1′)
S(1′)
C(1′)
O(1′)
C(2′)
O(2′)
C(3′)
O(3′)
C(4′)
O(4′)
C(11′)
C(12′)
C(13′)
C(14′)
C(15′)
C(16′)
C(17′)
Ta ble 3. Bon d Len gth s (Å)a a n d Selected Bon d
An gles (d eg)a for (CO)3Mn (η4-T‚C6H5) (6)
Bond Lengths
Mn-S
2.761(2)
2.079(4)
2.114(3)
1.777(5)
1.743(4)
1.803(3)
1.376(5)
1.386(5)
1.383(5)
1.384(6)
1.155(5)
1.164(4)
Mn-C(1)
Mn-C(3)
2.104(4)
2.088(4)
1.781(4)
1.775(4)
1.744(4)
1.407(6)
1.437(5)
1.390(5)
1.367(6)
1.372(5)
1.163(6)
Mn-C(2)
Mn-C(4)
Mn-C(12)
S-C(1)
Mn-C(11)
Mn-C(13)
S-C(4)
C(1)-C(2)
C(3)-C(4)
C(5)-C(10)
C(7)-C(8)
C(9)-C(10)
C(12)-O(12)
845(6)
S-C(5)
2284(5)
3191(5)
2669(5)
2842(6)
3504(1)
4778(1)
4846(5)
5646(4)
2234(5)
1414(5)
2264(5)
1505(5)
2641(5)
2037(4)
3770(5)
2304(6)
1601(7)
2311(6)
3760(6)
4480(6)
1540(8)
C(2)-C(3)
C(5)-C(6)
C(6)-C(7)
C(8)-C(9)
C(11)-O(11)
C(13)-O(13)
Bond Angles
C(1)-S-C(4)
C(1)-S-C(5)
S-C(1)-C(2)
Mn-S-C(5)
C(4)-S-C(5)
C(1)-C(2)-C(3)
C(2)-C(3)-C(4)
S-C(5)-C(6)
86.1(2)
108.8(2)
110.9(3)
146.0(1)
111.4(2)
111.0(3)
110.4(4)
117.2(3)
S-C(4)-C(3)
S-C(5)-C(10)
109.8(3)
122.4(3)
178.4(4)
178.8(4)
179.0(4)
95.0(2)
Mn-C(11)-O(11)
Mn-C(12)-O(12)
Mn-C(13)-O(13)
C(11)-Mn-C(12)
C(11)-Mn-C(13)
C(12)-Mn-C(13)
95.1(2)
91.1(2)
a
Numbers in parentheses are estimated standard deviations
in the least significant digits.
with thiophene (T) in the presence of AlBr3; however,
the yield was poor (3.5%). A higher yield route (74%)
involved the reaction of Mn(CO)5(O3SCF3) with T;3
however, this method required the prior synthesis of
Mn(CO)5(O3SCF3) and a large excess of thiophene. In
this paper, we describe a more efficient preparation (eq
3) of [(CO)3Mn(η5-T)]+ and [(CO)3Mn(η5-2,5-Me2T)]+. It
a
Equivalent isotropic U is defined as one-third of the trace of
the orthogonalized Uij tensor.
desired [(CO)3Mn(η5-T)]+ products in good (67-71%)
yield. This route is similar to that reported13 for the
synthesis of (CO)3Mn(η6-arene)+ complexes.
Rea ction s of [(CO)3Mn (η5-Th i)]+ (1 a n d 2) w ith
LiCu R2. Complexes 1 and 2 react (eq 4) with organo-
cuprates to give the (CO)3Mn(η4-T‚R) complexes (3, 5-7)
in 33-55% yield. These products are stable for a few
hours in air in the solid state. A byproduct (24-31%)
in all of these reactions is the known8 [Mn(CO)4(µ-I)]2,
which presumably forms from reaction with I- that is
begins with the in situ formation of Mn(CO)5BF4 from
the reaction of Mn(CO)5Br with AgBF4 in CH2Cl2
solvent; this intermediate is then reacted with thiophene
(T) or 2,5-dimethylthiophene (2,5-Me2T) to give the
(13) (a) Ryan, W. J .; Peterson, P. E.; Cao, Y.; Williard, P. G.;
Sweigart, D. A. Inorg. Chim. Acta 1993, 211, 1. (b) Woo, K.; Carpenter,
G. B.; Sweigart, D. A. Inorg. Chim. Acta 1994, 220, 297. (c) J ackson,
J . D.; Villa, S. J .; Bacon, D. S.; Pike, R. D.; Carpenter, G. B.
Organometallics 1994, 13, 3972.

Reactions of [(CO)3Mn(η5-Thi)]+ with Nucleophiles
Organometallics, Vol. 15, No. 1, 1996 329
Ta ble 5. Bon d Len gth s (Å)a a n d Selected Bon d
An gles (d eg)a for (CO)4Mn (SC6H4CH3)]2 (9)
Bond Lengths
Mn(1)-S(1)
Mn(1)-C(1)
Mn(1)-C(3)
Mn(2)-S(1)
Mn(2)-C(5)
Mn(2)-C(7)
S(1)-C(11)
C(1)-O(1)
C(3)-O(3)
C(5)-O(5)
C(7)-O(7)
2.394(1)
1.860(5)
1.816(5)
2.381(1)
1.875(5)
1.803(5)
1.788(4)
1.120(6)
1.137(6)
1.114(6)
1.149(6)
Mn(1)-S(2)
Mn(1)-C(2)
Mn(1)-C(4)
Mn(2)-S(2)
Mn(2)-C(6)
Mn(2)-C(8)
S(2)-C(21)
C(2)-O(2)
C(4)-O(4)
C(6)-O(6)
C(8)-O(8)
2.398(1)
1.864(5)
1.816(5)
2.416(1)
1.873(5)
1.819(5)
1.795(4)
1.130(6)
1.138(6)
1.116(6)
1.124(7)
Bond Angles
S(1)-Mn(1)-S(2)
S(2)-Mn(1)-C(1)
S(2)-Mn(1)-C(2)
S(1)-Mn(1)-C(3)
C(1)-Mn(1)-C(3)
S(1)-Mn(1)-C(4)
C(1)-Mn(1)-C(4)
C(3)-Mn(1)-C(4)
S(1)-Mn(2)-C(5)
S(1)-Mn(2)-C(6)
C(5)-Mn(2)-C(6)
S(2)-Mn(2)-C(7)
C(6)-Mn(2)-C(7)
S(2)-Mn(2)-C(8)
C(6)-Mn(2)-C(8)
Mn(1)-S(1)-Mn(2)
Mn(2)-S(1)-C(11)
Mn(1)-S(2)-C(21)
Mn(1)-C(1)-O(1)
Mn(1)-C(3)-O(3)
Mn(2)-C(5)-O(5)
82.4(1) S(1)-Mn(1)-C(1)
91.0(2) S(1)-Mn(1)-C(2)
86.6(1) C(1)-Mn(1)-C(2)
95.6(2) S(2)-Mn(1)-C(3)
91.3(2) C(2)-Mn(1)-C(3)
174.3(1) S(2)-Mn(1)-C(4)
93.8(2) C(2)-Mn(1)-C(4)
89.8(2) S(1)-Mn(2)-S(2)
84.2(2) S(2)-Mn(2)-C(5)
95.6(2) S(2)-Mn(2)-C(6)
173.6(2) S(1)-Mn(2)-C(7)
97.8(2) C(5)-Mn(2)-C(7)
89.3(2) S(1)-Mn(2)-C(8)
171.8(2) C(5)-Mn(2)-C(8)
94.5(2) C(7)-Mn(2)-C(8)
98.1(1) Mn(1)-S(1)-C(11)
116.1(2) Mn(1)-S(2)-Mn(2)
114.5(1) Mn(2)-S(2)-C(21)
177.4(5) Mn(1)-C(2)-O(2)
177.6(4) Mn(1)-C(4)-O(4)
179.4(5) Mn(2)-C(6)-O(6)
84.4(2)
88.1(2)
172.4(2)
176.8(2)
90.8(2)
92.3(2)
93.5(2)
82.3(1)
91.0(2)
82.7(2)
175.2(2)
91.0(2)
90.4(2)
91.9(2)
89.7(2)
112.6(1)
97.0(1)
113.0(1)
177.2(4)
179.2(5)
176.1(5)
F igu r e 1. Two views of the molecular structure of
(CO)3Mn(η4-T‚C6H5) (6).
(1.77 Å).14,15 The dihedral angle between the planes of
the phenyl group [C(5)-C(10)] and the four thiophene
carbons [C(1)-C(4)] is 89.4°. The carbon-carbon dis-
tances in the thiophene ring appear to exhibit a long-
short-long pattern, as observed in the following bond
lengths: C(1)-C(2) ) 1.407(6) Å, C(2)-C(3) ) 1.376-
(5), C(3)-C(4) ) 1.437(5). The Mn-C distances are
slightly shorter to C(2) (2.079(4) Å) and C(3) (2.088(4)
Å) than to C(1) (2.104(4) Å) and C(4) (2.114(3) Å). The
C-S bond distances [C(1)-S ) 1.743(4) Å, C(4)-S )
1.744(4)] are slightly longer than those (1.714(1) Å)16,17
in thiophene itself. The C(11)-O(11) ligand is es-
sentially eclipsed with the sulfur atom, as indicated by
a C(5)-S-Mn-C(11) torsion angle of 174.3(2)°. In
contrast, it might be noted that the sulfur in (CO)3Cr-
(η5-2,5-Me2T)18 is staggered with respect to the CO
ligands.
a
Numbers in parentheses are estimated standard deviations
in the least significant digits.
liberated in the formation of LiCuR2 from CuI and LiR:
CuI + 2LiR f LiCuR2 + LiI.
The η4-structure of the T‚C6H5 ligand in 6 is very
similar to that of η4 thiophene ligands16,17 in Cp*Ir(η4-
2,5-Me2T) (11)19 and Cp*Ir(η4-2,5-Me2T‚BH3) (12).20
Several η4-thiophene complexes, in which a second
metal fragment coordinates to the sulfur,17 also have
the folded envelope structure of 6, 11, and 12. The
magnitude of the fold angle between the four-carbon
plane and the C-S-C plane in 6 (30.4°) is significantly
less than that in 11 (42°) and 12 (39.8°). This also
affects the C-S-C angle, which is larger in 6 (86.1(2)°)
The molecular structure (Figure 1 with atom labels
used in the following discussion of the structure) of 6
determined by X-ray diffraction studies shows that the
phenyl group is bonded to the sulfur and the T‚Ph ligand
is η4-coordinated to Mn through the four carbons of the
thiophene. The sulfur is bent away from the Mn at a
distance of 2.761(2) Å; the sulfur is out of the C(1)-
C(2)-C(3)-C(4) plane by 0.645 Å and the dihedral angle
between the C(1)-C(2)-C(3)-C(4) and C(1)-S-C(4)
planes is 30.4°. The C(5)-S bond (1.803(3) Å) is slightly
longer than a typical C(sp2)-S single-bond distance
(14) Rozsondai, B.; Schultz, G.; Hargittai, I. J . Mol. Struct. 1981,
70, 309.
(15) Samdal, S.; Seip, H. M.; Torgrimsen, T. J . Mol. Struct. 1979,
57, 105.
(16) Angelici, R. J . Coord. Chem. Rev. 1990, 105, 61.
(17) Angelici, R. J . Bull. Soc. Chim. Belg. 1995, 104, 265-282.
(18) Sanger, M. J .; Angelici, R. J . Organometallics 1994, 13, 1821.
(19) Chen, J .; Angelici, R. J . Organometallics 1989, 8, 2277.
(20) Chen, J .; Daniels, L. M.; Angelici, R. J . J . Am. Chem. Soc. 1990,
112, 199.

330 Organometallics, Vol. 15, No. 1, 1996
Chen et al.
than in 11 (80.8(6)°) and 12 (82.6(5)°). Also, the metal-
sulfur distance is shorter in 6 (Mn-S ) 2.761(2) Å) than
in 11 (2.969(4) Å) and 12 (2.937(3) Å). The shorter
Mn-S distance may be due, at least in part, to the
smaller metallic radius21 of Mn (1.27 Å) compared to
that of Ir (1.36 Å). Molecular orbital calculations22 on
11 indicate that there is an antibonding interaction
between a sulfur 3p orbital and the iridium, which
makes the sulfur an unusually strong Lewis base.17 The
shorter Mn-S distance (2.761(2) Å) in 6 suggests that
there is less antibonding character to this interaction
than there is in 11 or 12. However, the Mn-S distance
is not as short as a typical Mn-S single bond, as occurs
in (η6-C6H6)(CO)2Mn(S-C6H5) (2.350(3) Å) and {[(η6-
mesitylene)(CO)2Mn]2(µ-SC6H5)}+ (2.358(2), 2.347(2) Å).23
analogous reactions of organolithium (RLi) and Grig-
nard reagents (RMgX) with π-hydrocarbon complexes,
e.g., (CO)3Mn(η6-arene)+, are often described2 as involv-
ing nucleophilic attack by R- groups. The reactions of
LiCuR2 (eq 4) can be described in the same general
manner. However, it should be noted that reactions of
PhLi and PhMgCl with [(CO)3Mn(η5-T)]+ in THF at -60
to -10 °C did not give the (CO)3Mn(η4-T‚R) complexes;
only decomposition was observed.
As discussed in the Introduction (eq 2), hydride
nucleophiles add to the C(2)-position of thiophene in
[(CO)3Mn(η5-T)]+. Nucleophiles [H- sources, OR-, SR-,
and -CH(CO2Me)2] also attack C(2) of thiophene in
CpRu(η5-T)+ to give products in which the C(2)-S bond
is cleaved.6,26 Reactions (eq 5) of Cp*Rh(η5-Me4T)2+
A complex (CO)3Mn(η4-C4(CF3)4S-C6F5) having es-
sentially the same structure as 6 was prepared previ-
ously by reaction24,25 of [Mn(CO)4(µ-SC6F5)]2 with
CF3C≡CCF3. All of the following structural parameters
are very similar to those in 6. The Mn-C distances are
shorter to C(3) (2.062 Å) and C(4) (2.068 Å) than to C(2)
(2.109 Å) and C(5) (2.103 Å). The dihedral angle
between the plane of the four-coordinated carbon atoms
and the C(2)-S-C(5) plane is 30.8°, while the Mn-S
distance is 2.793 Å.
In 6, three carbons are bonded to the sulfur, which
suggests that there is a positive charge on the sulfur
as in sulfonium ions (R3S+) and that the T-C6H5+ ligand
behaves as a four-electron donor to the Mn(CO)3 group.
This method of counting electrons gives the Mn(CO)3
group a negative charge and the Mn atom an 18-electron
count. Although we expected the negatively charged
manganese to act as a donor toward Lewis acids, 3 did
not react with W(CO)5(THF) in THF at room tempera-
ture, nor did it react with Mo(CO)3(NCMe)3 or PhC≡CPh
under the same conditions.
(where Me4T ) tetramethylthiophene) and (η6-arene)-
Ru(η5-Me4T)2+ with OH- yield products resulting from
OH- addition to either C(2) (14) or S (13). Rauch-
fuss27,28 provides convincing evidence that initial attack
leading to both types of products occurs at the sulfur.
He suggests that sulfur may, in general, be the most
electrophilic atom in the η5-thiophene ligand.
The similarity of their IR and 1H NMR spectra
suggest that complexes 3, 5, and 7 have the same basic
structure as 6. All have two ν(CO) bands at ap-
proximately 1990 (vs) and 1900 (vs br) cm-1. In 1H
NMR spectra of 5 and 7, the H(3) and H(4) (see eq 4 for
the labeling scheme) protons of the η4-2,5-Me2T‚R ligand
occur at δ 4.84 and 4.95, which is considerably upfield
of the same protons (δ 7.10) in thiophene. Such upfield
shifts are characteristic of protons on thiophene carbons
that are coordinated to metals.17 The chemical shift for
H(3) and H(4) in 6 is very similar to that in 11 (δ 4.53)19
and 12 (δ 4.46).20 The assignment of the H(3) and H(4)
protons in 5 and 7 allows one to assign the δ 5.28
resonance of the η4-T‚R complexes (3 and 6) to H(3) and
H(4). This leaves the upfield signals at δ 2.40 for 3 and
δ 2.72 for 6 to be assigned to the H(2) and H(5) protons.
The H(2) and H(5) protons (δ 3.08) are also upfield of
H(3) and H(4) (δ 4.89) in Cp*Ir(η4-T).20
The reactions (eq 4) of LiCuR2 with [(CO)3Mn(η5-T)]+
are examples of "nucleophilic" R- addition to the
thiophene sulfur. In reactions (eq 2) of H- sources with
[(CO)3Mn(η5-Thi)]+, H- adds to C(2) or C(5) only when
they do not bear methyl substituents. Thus, one might
expect LiCuR2 attack to occur at C(2) or C(5) when they
are not methyl-substituted. However, both the η5-T and
η5-2,5-Me2T complexes (1 and 2) give the S-addition
products. The lack of C(2)-addition products may be a
result of the kinetically inert S-R bond, which prevents
migration from S to C(2).
Rea ction s of [(CO)3Mn (η5-Th i)]+ (1 a n d 2) w ith
Oth er Nu cleop h iles. Thiolate (RS-) nucleophiles
react6,26 with CpRu(η5-T)+ to give products resulting
from RS- addition to C(2) and cleavage of the C(2)-S
bond. Phenylthiolate adds to an arene carbon of
[(CO)3Mn(η6-arene)]+ to give the (phenylthio)cyclohexa-
dienyl complexes (CO)3Mn(η5-C6R6‚SPh).1,2 Thus, it was
expected that RS- would add to the η5-Thi ring in [(CO)3-
Mn(η5-Thi)]+. Instead, these reactions (eq 6) lead to loss
of the thiophene and formation of [Mn(CO)4(µ-SR)]2 in
50-57% yield, based on the amount of starting Mn
complex. Despite the reasonably high yields, the reac-
tions must be complicated since each Mn in 1 and 2
The mechanism of R- group transfer (eq 4) from
LiCuR2 to [(CO)3Mn(η5-Thi)]+ is not known. However,
(21) Wells, A. F. Structural Inorganic Chemistry, 5th ed.; Clarendon
Press: Oxford, UK, 1984.
(22) Harris, S. Organometallics 1994, 13, 5132.
(23) Schindehutte, M.; van Rooyen, P. H.; Lotz, S. Organometallics
1990, 9, 293.
(24) Davidson, J . L.; Sharp, D. W. A. J . Chem. Soc., Dalton Trans.
1975, 2283.
(25) (a) Barrow, M. J .; Davidson, J . L.; Harrison, W.; Sharp, D. W.
A.; Sim, G. A.; Wilson, F. B. J . Chem. Soc., Chem. Commun. 1973,
583. (b) Barrow, M. J .; Freer, A. A.; Harrison, W.; Sim, G. A.; Taylor,
D. W.; Wilson, F. B. J . Chem. Soc., Dalton Trans. 1975, 197.
(26) Hachgenei, J . W.; Angelici, R. J . J . Organomet. Chem. 1988,
355, 359.
(27) Skaugset, A. E.; Rauchfuss, T. B.; Wilson, S. R. J . Am. Chem.
Soc. 1990, 114, 8521.
(28) Krautscheid, H.; Feng, Q.; Rauchfuss, T. B. Organometallics
1993, 12, 3273.

Reactions of [(CO)3Mn(η5-Thi)]+ with Nucleophiles
Organometallics, Vol. 15, No. 1, 1996 331
begins with three CO ligands but finishes with four in
8 and 9. The dimeric products are known and have been
prepared by more direct routes.29 To our knowledge,
no X-ray structural studies of [(CO)4Mn(µ-SR)]2 com-
plexes have been reported. However, the structure of
[(CO)4Mn(µ-SeCF3)]2 has been published30 and is similar
to that described for 9 herein.
F igu r e 2. Thermal ellipsoid drawing of [(CO)4Mn(µ-SC6H4-
CH3-p)]2 (9).
52% yield, based on the amounts of reactants 1 and 2.
This is clearly a complicated reaction involving reduc-
tion of the manganese and transfer of CO groups among
manganese atoms.
The thermal ellipsoid drawing (Figure 2) of [(CO)4Mn-
(µ-SC6H4CH3-p)]2 (9) shows that the molecule has a
planar Mn2S2 core with nearly equal Mn-S bond
distances (from 2.381(1) to 2.416(1) Å, Table 5). These
distances are slightly longer than those in the terminal
thiolate complex (η6-C6H6)Mn(CO)2(SPh) (2.350(3) Å)
and the bridging thiolate {[(η6-1,3,5-C6Me3H3)(CO)2-
Mn]2(µ-SPh)}+ (2.347(2), 2.358(2) Å).23 The Mn-S-Mn
angles (98.1(1), 97.0(1)°) in the Mn2S2 unit are relatively
open compared with the S-Mn-S angles (82.4(1), 82.3-
(1)°). The Mn-CO bond distances (average ) 1.868 Å)
are distinctly longer for the CO ligands trans to each
other than those (average ) 1.813 Å) trans to the
bridging sulfur ligands. This is consistent with stronger
π-backbonding to the CO groups trans to the sulfur. The
C-O distances are marginally shorter for the CO groups
trans to each other (average ) 1.120 Å) than those
(1.137 Å) that are trans to the sulfur, which is also in
agreement with π-backbonding to the CO ligands. The
tolyl groups on the bridging sulfur atoms are anti to
each other. Their size increases the S-Mn-COax angles
to the axial COs that are on the same side of the Mn2S2
plane as the tolyl groups. Thus, the S(1)-Mn(1)-C(2)
angle (88.1(2)°) is larger than the S(1)-Mn(1)-C(1)
angle (84.4(2)°). Each manganese has an octahedral
coordination geometry.
In conclusion, reactions of the [(CO)3Mn(η5-Thi)]+
complexes with nucleophiles give a variety of products.
The most notable are those obtained from the organo-
cuprates LiCuR2, which give (eq 4) the (CO)3Mn(η4-
Thi‚R) complexes. These studies show that, depending
on the nucleophile, [(CO)3Mn(η5-Thi)]+ may be attacked
at the sulfur or C(2) or the thiophene can be displaced
to form a range of other products.
Ack n ow led gm en t. This research was supported by
the Office of Basic Energy Sciences, Chemical Sciences
Division of the U.S. Department of Energy, under
contract W-7405-Eng-82 to Iowa State University. We
appreciate the loan of IrCl3 from J ohnson Matthey, Inc.
Reactions (eq 7) of the [(CO)3Mn(η5-Thi)]+ complexes
with OCH3- or -CH(CO2CH3)2 lead to Mn2(CO)10 in 45-
Su p p or tin g In for m a tion Ava ila ble: Tables of bond
distances and angles, torsion angles, and least-squares planes
for 6 and 9 (10 pages). Ordering information is given on any
current
(29) Treichel, P. M. In Comprehensive Organometallic Chemistry;
Wilkinson, G., Ed.; Pergamon Press: Oxford, U.K., 1982; Vol. 4, pp
104.
(30) Marsden, C. J .; Sheldrick, G. M. J . Organomet. Chem. 1972,
40, 175.
masthead page.
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