Cationic (η6-Arene)tricarbonylmanganese Linked to Ferrocene Complexes

Article abstract of DOI:10.1021/om034168f

Palladium-catalyzed Sonogashira coupling reactions of the neutral [η ⁵(1-5)-(1-chloro-4-methoxycyclohexa-2,4-dienyl)] tricarbonylmanganese(I) (2) and 2-bromo-5-{[η ⁵(1-5)-(4-methoxycyclohexa-2,4-dienyl]tricarbonylmanganese(I)} thioph

Full text of DOI:10.1021/om034168f

184
Organometallics 2004, 23, 184-193
Ca tion ic (η6-Ar en e)tr ica r bon ylm a n ga n ese Lin k ed to
F er r ocen e Com p lexes
Be´atrice J acques, J ean-Philippe Tranchier, Franc¸oise Rose-Munch,* and
Eric Rose*
Laboratoire de Synthe`se Organique et Organome´tallique, UMR CNRS 7611, Universite´ Pierre
et Marie Curie, Tour 44 1er e´tage, BP 181, 4 Place J ussieu, 75252 Paris Cedex 05, France
G. Richard Stephenson
Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy,
University of East Anglia, Norwich NR4 7TJ , U.K.
Carine Guyard-Duhayon
Laboratoire de Chimie Inorganique et Mate´riaux Mole´culaires,
Unite´ de Recherche 7071-CNRS, Universite´ Pierre et Marie Curie, 4 Place J ussieu,
BP 42, 75252 Paris Cedex 05, France
Received September 12, 2003
Palladium-catalyzed Sonogashira coupling reactions of the neutral [η5(1-5)-(1-chloro-4-
methoxycyclohexa-2,4-dienyl)]tricarbonylmanganese(I) (2) and 2-bromo-5-{[η5(1-5)-(4-meth-
oxycyclohexa-2,4-dienyl]tricarbonylmanganese(I)}thiophene (13) with the ethynylferrocene
derivative 5 give the dinuclear complexes 1-(ferrocenylethynyl)[η5(1-5)-(4-methoxycyclohexa-
2,4-dienyl)]tricarbonylmanganese(I) (6) and 2-(ferrocenylethynyl)-5-[η5(1-5)-(4-methoxycy-
clohexa-2,4-dienyl)tricarbonylmanganese]thiophene (10). Similarly, condensation of 2 with
2-(ferrocenylethynyl)-5-ethynylthiophene (18) affords the dinuclear complex 19. These
complexes are valuable precursors, upon hydride abstraction, of the corresponding η6-arene
cations 7, 11, and 20. The structure of one of them, 1-(ferrocenylethynyl)[η6(1-6)-(4-
methoxybenzene)]tricarbonylmanganese(I) tetrafluoroborate (7), has been investigated by
X-ray diffraction.
In tr od u ction
Organometallic chromophores have recently received
increasing attention, motivated by the need to probe the
properties of electron delocalization when the two end
groups are linked with extended π conjugation. When
they contain the main features donor-π system-
acceptor, they offer a large diversity of tunable electronic
behavior due to the size, nature, and redox ability of
the transition-metal atoms,1,2 which confer to them
interesting properties: for example, optoelectronical and
electrical applications.3 A small number of heterobime-
tallic complexes with such a form have been described
in the literature and usually contain, as end groups,
metallocenyl derivatives (metal ) Fe,4 Ru,5) and Cr or
W complexes.6 As for conjugated dinuclear complexes
containing cationic Mn complexes, to our knowledge,
only two articles have been reported.7a,b The first
complexes of type A (Figure 1) contain a cationic
tricarbonyl(thiophene)manganese group linked to a
ferrocene or to an (η6-arene)tricarbonylchromium group
by a conjugated double-bond system.7a,b Those of type
F igu r e 1. Dinuclear complexes containing cationic Mn
complexes.
B (Figure 1) have a cationic (η6-arene)tricarbonylman-
ganese group conjugated with an (η6-arene)tricarbon-
(3) (a) Plyta, Z.; Prim, D.; Tranchier, J .-P.; Rose-Munch, F.; Rose,
E. Tetrahedron Lett. 1999, 40, 6769-6771. (b) Lee, I. S.; H. Seo, H.;
Chung, Y. K. Organometallics 1999, 18, 1091-1096. (c) Balavoine, G.
G. A.; Daran, J . C.; Iftime, G.; Lacroix, P. G.; Manoury, E.; Delaire, J .
A.; Maltey-Fanton, I.; Nakatani, K.; Di Bella, S. Organometallics 1999,
18, 21-29. (d) J ayprakash, K. N.; Ray, P. C.; Matsuoka, I.; Bhadbhade,
M. M.; Puranik, V. G.; Das, P. K.; Nishihara, H.; Sarkar, A. Organo-
metallics 1999, 18, 3851-3858. (e) Heck, J .; Dabeck, S.; Meyer-
Friedrichsen, T.; Wong, H. Coord. Chem. Rev. 1999, 190-192, 1217-
1254. (f) Le Bozec, H.; Renouard, T. Eur. J . Inorg. Chem. 2000, 229-
239. (g) Farrell, T.; Meyer-Friedrichsen, T.; Heck, J .; Manning, A. R.
Organometallics 2000, 19, 3410-3419. (h) Prim, D.; Auffrant, A.; Rose-
Munch, F.; Rose, E.; Vaissermann, J . Organometallics 2001, 20, 1901-
1903. (i) Tranchier, J . P.; Chavignon, R.; Prim, D.; Auffrant, A.; Planas,
J . G.; Rose-Munch, F.; Rose, E.; Stephenson, G. R. Tetrahedron Lett.
2001, 42, 3311-3313. (j) Mata, J . A.; Peris, E.; Llusar, R.; Uriel, S.;
Cifuentes, M. P.; Humphrey, M. G.; Samoc, M.; Luther-Davies, B. Eur.
J . Inorg. Chem. 2001, 2113-2122. (k) Demadis, K. D.; Hartshorn, C.
M.; Meyer, T. J . Chem. Rev. 2001, 101, 2655-2685. (l) Mata, J . A.;
Peris, E.; Uriel, S.; Llusar, R.; Asselberghs, I.; Persoons, A. Polyhedron
2001, 20, 2083-2088. (m) Meyer-Friedrichsen, T.; Wong, H.; Prosenc,
M. H.; Heck, J . Eur. J . Inorg. Chem. 2003, 5, 936-946.
(1) Goovaerts, E.; Wenseleers, W. E.; Garcia, M. H.; Cross, G. H.
Handbook of Advanced Electronic and Photonic Materials and Devices;
Nalwa, H. S., Ed.; Academic Press: New York, 2001; Vol. 9, Chapter
3, pp 127-191.
(2) (a) Long, N. J .; Angew. Chem., Int. Ed. Engl. 1995, 34, 21-38.
(b) Marder, S. R. Inorganic Materials, 2nd ed.; Bruce, D. W., O’Hare,
D., Eds.; Wiley: New York, 1996; Chapter 3, pp 122-169.
10.1021/om034168f CCC: $27.50 © 2004 American Chemical Society
Publication on Web 12/16/2003

(η6-Arene)tricarbonylmanganese Linked to Ferrocenes
Organometallics, Vol. 23, No. 2, 2004 185
Sch em e 1. P r ep a r a tion of
(Ar en e)tr ica r bon ylm a n ga n ese Com p lexes via a
Tw o-Step P r oced u r e
Sch em e 3. F or m a tion of a Din u clea r Mn -P d
Com p lex
rivative. Moreover, whereas the presence of the cationic
electron-withdrawing tricarbonylmanganese entity ac-
tivates the carbon-chlorine bond toward Pd(0) oxidative
addition, no report of Pd-catalyzed carbon-carbon bond
formation has been published to our knowledge. Indeed,
we have shown12 that although palladium inserts into
the carbon-chlorine bond, the resulting bimetallic Mn/
Pd complex is so stable that it did not give any further
reaction (Scheme 3): no coupling reaction was observed.
Syn th esis of Com p lex 7. Thus, to access the bi-
metallic target structures, we used as our starting
material an η5 complex, namely (η5-1-chloro-4-methoxy-
cyclohexadienyl)Mn(CO)3 (2). This complex is easily
accessible by employing the nucleophile addition chem-
istry described above, by regioselective hydride addition
Sch em e 2. Rea ctivity of Ch lor oben zen e
Com p lexes
ylchromium entity.7a In both cases, the last step of the
synthesis of the final complex consists of the coordina-
tion of the carbonylmanganese entity to the arene ring,
a process which usually requires severe reaction condi-
tions. An alternative procedure has used a transfer of
an Mn(CO)3 moiety, but the preparation of the transfer
agent complex was found to be time consuming and in
our hands proceeded only in moderate yield.7a,c
to (η6-1-chloro-4-methoxybenzene)Mn(CO)3 tetrafluo-
+
Here, we report an efficient synthesis of heterobime-
+
tallic complexes containing cationic (η6-arene)Mn(CO)3
roborate (1) (Scheme 4).8,9,11a,13,14 Functionalization of
(η5-chlorocyclohexadienyl)Mn(CO)3 derivatives is ef-
ficient,15 and C-O,15d C-N,15d C-S,15d C-P,15d and
C-C8,15a,b,d bond formation are achieved by Pd-catalyzed
reactions (Negishi, Sonogashira, and Stille reactions).
An advantage of this strategy comes from the fact that
neutral η5 Mn complexes are stable and can be purified
by silica gel column chromatography, in contrast to the
cationic polar η6-Mn structures. Ethynylferrocene 5 was
prepared by classical methods in 80% yield by treating
acetylferrocene (3) with POCl3, DMF, and NaOAc. The
resulting conjugated chloro aldehyde 4 was treated with
complexes and a ferrocenyl entity via a two-step pro-
cedure that we have recently developed8 in the case of
mononuclear complexes (Scheme 1). The first step (a)
involves a palladium-catalysis strategy for functional-
ization of (η5-1-chlorocyclohexadienyl)Mn(CO)3. This
method preserves the methylene group and allows the
second step (b): the rearomatization of the η5 complex
by hydride abstraction, which leads to new cationic (η6-
+
arene)Mn(CO)3 complexes.
Resu lts a n d Discu ssion
Ipso chloride substitution in (η6-chloroarene)tricar-
bonylmanganese complexes allows a clean nucleophile
introduction, but such a strategy is limited to amino,
oxo, and thio derivatives (Scheme 2, path a; Nu ) NR2,
OR, SR).9 The main reaction for Mn complexes is the
addition reaction, which leads to stable neutral (η5-cy-
clohexadienyl)tricarbonylmanganese complexes (Scheme
2, path b),10 whose reactivity has been described in
several studies.11
(10) (a) Balssa, F.; Aniss, K.; Rose-Munch, F. Tetrahedron Lett. 1992,
33, 1901-1902. (b) Rose-Munch, F.; Susanne, C.; Balssa, F.; Rose, E.
J . Organomet. Chem. 1994, 476, C25-C26. (c) McDaniel, K. In
Comprehensive Organometallic Chemistry; Abel, W., Stone, F. G. A.,
Wilkinson, G., Eds.; Pergamon: Oxford, U.K., 1995; Vol. 6, Chapter
4, p 93. (d) Balssa, F.; Gagliardini, V.; Le Corre-Susanne, C.; Rose-
Munch, F.; Rose, E.; Vaissermann, J . Bull. Soc. Chim. Fr. 1997, 134,
537-541. (e) Rose-Munch, F.; Gagliardini, V.; Renard, C.; Rose, E.
Coord. Chem. Rev. 1998, 178-180, 249-268. (f) Renard, C.; Valentic,
R.; Rose-Munch, F.; Rose, E. Organometallics 1998, 17, 1587-1594.
(g) Rose, E.; Le Corre-Susanne, C.; Rose-Munch, F.; Renard, C.;
Gagliardini, V.; Teldji, F.; Vaissermann, J . Eur. J . Inorg. Chem. 1999,
421-423. (h) Rose-Munch, F.; Rose, E. Eur. J . Inorg. Chem. 2002, 6,
1269-1283. (i) Auffrant, A. Ph.D. Thesis, Universite´ P. et M. Curie,
J uly 19, 2002, p 227. (j) Comte, V.; Tranchier, J . P.; Rose-Munch, F.;
Rose, E.; Perrey, D.; Richard, D.; Moise, C. Eur. J . Inorg. Chem. 2003,
1893-1899.
Thus, the formation of a carbon-carbon bond is not
possible by nucleophilic substitution starting from a
cationic (η6-chlorobenzene)tricarbonylmanganese de-
(4) (a) Mu¨ller, T. J . J .; Netz, A.; Ansorge, M.; Schmalzlin, E.;
Bra¨uchle, C.; Meerholz, K. Organometallics 1999, 18, 5066-5074. (b)
Mu¨ller, T. J . J .; Ansorge, M.; Lindner, H. J . Chem. Ber. 1996, 129,
1433-1440.
(5) Garcia, M. H.; Royer, S.; Robalo, M. P.; Dias, R. A.; Tranchier,
J . P.; Chavignon, R.; Prim, D.; Auffrant, A.; Rose-Munch, F.; Rose, E.;
Vaissermann, J .; Persoons, A.; Asselberghs, I. Eur. J . Inorg. Chem.,
in press.
(6) (a) Houbrechts, S.; Clays, K.; Persoons, A.; Cadierno, V.; Gamasa,
M. P.; Gimeno, J . Organometallics 1996, 15, 5266-5268. (b) Cadierno,
V.; Conejero, S.; Pilar Gamasa, M.; Gimeno, J .; Asselberghs, I.;
Houbrechts, S.; Clays, K.; Persoons, A.; Borge, J .; Garcia-Granda, S.
Organometallics 1999, 18, 582-597.
(7) (a) Su, S. L.; Lee, T.-Y.; Lee, J . E.; Lee, I.-S.; Chung, Y. K.; Lah,
M. S. Organometallics 1996, 15, 3664-3669. (b) Lee, I. S.; Seo, H.;
Chung, Y. K. Organometallics 1999, 18, 1091-1096. (c) Sun, S.; Yeung,
L. K.; Sweigart, D. A.; Lee, T.-Y.; Lee, S. S.; Chung, Y. K.; Switzer, S.
R.; Pike, R. D. Organometallics 1995, 14, 2613-2615.
(8) Auffrant, A.; Prim, D.; Rose-Munch, F.; Rose, E.; Schouteeten,
S.; Vaissermann, J . Organometallics 2003, 22, 1898-1913.
(9) Pauson, P. L.; Segal, J . A. J . Chem. Soc., Dalton Trans. 1975,
1677.
(11) (a) Brookhart, M.; Lamanna, W.; Pinhas, A. R. Organometallics
1983, 2, 638-6649. (b) Brookhart, M.; Lukacs, A. J . Am. Chem. Soc.
1984, 106, 4161-4166. (c) Kane-Maguire, L. A. P.; Honig, E. D.;
Sweigart, D. A. Chem. Rev. 1984, 84, 525-543. (d) Rush, P. J .; Noh,
S. K.; Brookhart, M. Organometallics 1986, 5, 1745-1747. (e) Hyeon,
T. H.; Chung, T. M.; Chung, Y. K. Bull. Korean Chem. Soc. 1989, 10,
500-505. (f) Pike, R. D.; Ryan, W. J .; Lenhoff, N. S.; Van Epp, J .;
Sweigart, D. A. J . Am. Chem. Soc. 1990, 112, 4798-4804. (g) Sheridan,
J . B.; Padda, R. S.; Chaffee, K.; Wang, C.; Huang, Y.; Lalancette, R. J .
Chem. Soc., Dalton Trans. 1992, 1539-1549. (h) Roell, B. C.; McDaniel,
K. F.; Vaughan, W. S.; Macy, T. S. Organometallics 1993, 12, 224-
228. (i) Pearson, A. J .; Shin, H. J . Org. Chem. 1994, 59, 2314-2323.
(j) Balssa, F.; Gagliardini, V.; Rose-Munch, F.; Rose, E. Organometallics
1996, 15, 4373-4382. (k) Pearson, A.; Vickerman, R. J . Tetrahedron
Lett. 1998, 39, 5931-5932. (l) Woo, K.; Cao, Y.; Li, H.; Yu, K.;
Carpenter, G. B.; Sweigart, D. A.; Robinson, B. H. J . Organomet. Chem.
2001, 630, 84-87.
(12) Carpentier, J . F.; Castanet, Y.; Brocard, J .; Mortreux, A.; Rose-
Munch, F.; Susanne, C.; Rose, E. J . Organomet. Chem. 1995, 493, C22-
C24.
(13) Pauson, P. L.; Segal, J . A. J . Chem. Soc., Dalton Trans. 1975,
1683-1686.

186 Organometallics, Vol. 23, No. 2, 2004
J acques et al.
a
Ta ble 1. Cr ysta l Da ta for C22H16BF eF 4Mn O4
Sch em e 4. Ad d ition of Hyd r id e to th e
Ch lor oa r en e Com p lex 1
formula
cryst class
space group
a (Å)
b (Å)
c (Å)
C22H16BFeF4MnO4
orthorhombic
P21cn
12.060(4)
12.829(4)
14.042(4)
90
R (deg)
â (deg)
90
90
Sch em e 5. P r ep a r a tion of th e Din u clea r Com p lex
7
γ (deg)
V (Å3)
2172(1)
4
Z
radiation type
wavelength (Å)
density (g cm-3
Mr
Mo KR
0.710 690
1.66
541.94
13.10
)
µ (cm-1
)
temp (K)
size (mm)
color
295
0.20 × 0.20 × 0.30
dark red
block
shape
diffractometer
scan type
no. of rflns measd
Enraf-Nonius Cad-4
2θ/ω
2437
no of indep rflns
2413
θ(min,max)
index ranges
1, 26.00
h
k
l
0-14
0-15
0-17
155
1 N NaOH to afford ethynylferrocene 5 in 90% yield
(Scheme 5).16
secondary extinction coeff
decay
0.02
refinement
on F
Ethynylferrocene 5 reacted with (η5-1-chloro-4-meth-
oxycyclohexadienyl)Mn(CO)3 complex 2 in the presence
of Pd2dba3 and AsPh3 at 40 °C in NEt3 for 22 h to afford
6 in 78% yield. This catalytic system has been proved
to be the most efficient in the synthesis of alkyne-
substituted (η5-cyclohexadienyl)Mn(CO)3 complexes.8
Triphenylcarbenium ion reagents are able to oxidize
ferrocene to ferrocenium, but despite the presence of a
R ) ∑(|Fo| - |Fc|)/∑|Fo|
0.0699
0.0756
-0.58
0.77
1547
1.50
2
1/2
Rw ) [∑w(||Fo| - |Fc||)2/∑wFo
]
∆Fmin (e Å-3
)
)
∆Fmax e Å-3
no. of rflns used
σ(I) limit
no. of params
goodness of fit
250
1.010
a
Weighting scheme of the form w ) w′[1 - (||Fo| - |Fc||)/
6σ(Fo))2]2 with w′)1/∑rArTr(X) with coefficients 2.90, 0.815, and
2.27 for a Chebychev series for which X ) Fc/Fc(max).
-
ferrocenyl substituent in 6, reaction with CPh3+BF4
proceeded smoothly to deliver 7 in 92% yield (Scheme
5). The favored site of reaction is thus the neutral
(cyclohexadienyl)manganese complex, and overall hy-
dride abstraction occurs in preference to electron-
transfer redox chemistry at iron. The mechanism of
hydride abstraction from (cyclohexadienyl)manganese
may involve an initial electron-transfer step followed
by transfer of H• to Ph3C•.17 Our results show that
reaction at the organomanganese moiety is preferred
over the possibility of ferrocene redox chemistry. Heck
et al. reported also an hydride abstraction in the case
of bimetallic sesquifulvalene complexes.3e
lengths are presented in Figures 2 and 3, and crystal
data are reported in Table 1.
Three important features can be emphasized. First,
the cation displays the well-known piano-stool confor-
mation found in half-sandwich tricarbonyl complexes.20
The conformation adopted by the Mn(CO)3 entity is
significant, because the η6-arene is substituted by two
electron-donating groups: the methoxy group and the
ferrocenylacetylene. These effects compete and, in the
solid state, the almost staggered conformation of the
tripod shows a slightly dominant effect of the methoxy
group. Indeed, the values of the torsion angles C(6)-
C(100)-Mn-C(22), C(4)-C(100)-Mn-C(20) and C(2)-
C(100)-Mn-C(21), C(100) being the center of the six-
membered ring, are 17, 18, and 17°. This conclusion can
be drawn because it is well reported in the case of
substituted (η6-arene)Cr(CO)3 complexes that the con-
formation of the Cr(CO)3 entity with respect to the arene
X-r a y An a lysis of Com p lex 7. Crystals of 1-(ferro-
cenylethynyl)[η6-(4-methoxybenzene)]tricarbonylman-
ganese (7) were grown in a petroleum ether/acetone
mixture. Two CAMERON views and some selected bond
(14) (a) Auffrant, A.; Prim, D. Rose-Munch, F.; Rose, E. C. R. Chimie
2002, 5, 137-141. (b) Rose-Munch, F.; Balssa, F.; J acques, B.; Rose,
E.; Dromzee, Y. C. R. Chim. 2003, 581-588.
(15) (a) Prim, D.; Auffrant, A.; Rose-Munch, F.; Rose, E.; Vaisser-
mann, J . Organometallics 2001, 20, 1901-1903. (b) Auffrant, A., Prim,
D.; Rose-Munch, F.; Rose, E.; Vaissermann, J . Organometallics 2001,
20, 3214-3216. (c) Auffrant, A.; Prim, D.; Rose-Munch, F.; Rose, E. C.
R. Chimie 2002, 5, 137-141. (d) Auffrant, A.; Prim, D.; Rose-Munch,
F.; Rose, E.; Vaissermann, J . Organometallics 2002, 21, 3500-3502.
(e) Prim, D.; Andrioletti, B.; Rose-Munch, F.; Rose, E.; Couty, F.
Tetrahedron 2003, submitted.
(18) (a) Watkin, D. J .; Prout, C. K.; Carruthers, J . R.; Betteridge,
P. W. Crystals, issue 10; Chemical Crystallography Laboratory,
University of Oxford, Oxford, U.K., 1996. (b) Cromer, D. T. Interna-
tional Tables for X-ray Crystallography; Kynoch Press: Birmingham,
U.K., 1974; Vol. IV.
(19) Altomare, A.; Cascarano, G.; Giacovazzo, G.; Guagliardi, A.;
Burla, M. C.; Polidori, G.; Camalli, M. SIR92-A Program for Automatic
Solution of Crystal Structures by Direct Methods. J . Appl. Crystallogr.
1994, 27, 435.
(16) Polin, J .; Schottenberger, H. Org. Synth. 1996, 73, 262-269.
(17) (a) Astruc, D. Electron Transfer and Radical Processes in
Transition-Metal Chemistry; VCH: Weinheim, Germany, 1995. (b)
Astruc, D., Ed. Modern Arene Chemistry; Wiley-VCH: Weinheim,
Germany, 2002.
(20) Berndt, A. F.; Marsh, R. E. Acta Crystallogr. 1963, 16, 118-
125.

(η6-Arene)tricarbonylmanganese Linked to Ferrocenes
Organometallics, Vol. 23, No. 2, 2004 187
F igu r e 2. CAMERON view of the molecular structure of complex 7 (C22H16BFeF4MnO4). Selected bond lengths (Å): Mn-
C1 ) 2.207(12), Mn-C2 ) 2.163(9), Mn-C3 ) 2.168(13), Mn-C4 ) 2.265(12), Mn-C5 ) 2.182(13), Mn-C6 ) 2.155(12),
C1-C7 ) 1.399(19), C7-C8 ) 1.199(18), C8-C9 ) 1.42(2), Mn-C20 ) 1.803(14), C20-O20 ) 1.135(16), C9-C10 ) 1.48(2),
C10-C11 ) 1.39(2), C11-C12 ) 1.36(3), C12-C13 ) 1.40(3), C13-C9 ) 1.41(2), Fe-C9 ) 2.031(16), Fe-C10 ) 2.052(17),
Fe-C11 ) 2.008(19), Fe-C12 ) 2.042(16), Fe-C13 ) 2.04(1).
Sch em e 6. P r ep a r a tion of th e Din u clea r Com p lex
11
F igu r e 3. CAMERON view of the structure of complex 7
with the Mn(CO)3 tripod projected onto the arene ring.
ring depends on the nature of the substituent.10h An
electron-donating group, for example, favors the eclipsed
conformation of the substituent by a Cr-CO bond. We
observed a similar effect21,22 in the case, for example,
of (anisole)tricarbonylchromium substituted at the para
position by the thiophenyl group,21 where the corre-
sponding torsion angles are 22, 22, and 23°. Second, the
arene ring and C7 atom were found to be almost
coplanar, as well as the Cp ring and C8 carbon atom.
The methoxy group lies in the arene ring plane. The
Mn-C(ring) bond lengths ranging from 2.15 to 2.27 Å
(average 2.19 Å) are similar to the corresponding
two metal atoms lie on the opposite faces of the
conjugated system, probably for steric reasons. The
antiperiplanar alignment of the two metal centers
across the alkyne link is very pronounced. This is
consistent with a high degree of orbital overlap through
the extended π system. These data are remarkable,
because dinuclear derivatives of comparable sesquiful-
valene complexes all adopt a synperiplanar conforma-
tion.3e
+
distances of other para-disubstituted (anisole)Mn(CO)3
derivatives such as those substituted by a trimethylsilyl
ynone or a thienyl ketone group.8
The arene, the Cp ring, and the triple bond are in the
same plane. Therefore, an ideal overlap of the π system
and a strong electronic coupling can be assumed in the
solid state. The third point concerns the position of the
Mn and Fe atoms: the structure shows clearly that the
Syn th esis of Com p lex 11. Two possible routes could
be considered to prepare the heterodinuclear complex
11 which is homologated by a thienyl unit (Schemes 6
and 7). The first methodology involved a Sonogashira
coupling with ethynylferrocene (5) and 2-bromothiophene
in the presence of CuI, NEt3, and PdCl2(PPh3)2 (Scheme
6), which yielded the ferrocene derivative 8 in 64% yield.
This compound was lithiated with lithium diisopropyl-
(21) Prim, D.; Tranchier, J . P.; Rose-Munch, F.; Rose, E. Eur. J .
Inorg. Chem. 2000, 901-905.
(22) In the case of chromium complexes, see: (a) Boutonnet, J . C.;
Rose-Munch, F.; Rose, E.; J eannin, Y.; Robert, Y. J . Organomet. Chem.
1985, 297, 185-191. (b) Rose-Munch, F.; Bellot, O.; Mignon, L.; Semra,
A.; Robert, F.; J eannin, Y. J . Organomet. Chem. 1991, 402, 1-16.

188 Organometallics, Vol. 23, No. 2, 2004
J acques et al.
Sch em e 7. P r ep a r a tion of th e Din u clea r Com p lex
11
Sch em e 9. P r ep a r a tion of th e Din u clea r Com p lex
20
Sch em e 8. P r ep a r a tion of th e Mon on u clea r
Com p lex 15
Ta ble 2. Selected 1H NMR Da ta (p p m )
complex
proton
7
11
20
H2
H3
7.35
6.62
0.73
4.46
4.64
7.58
6.63
0.95
4.39
4.58
7.43
6.63
0.80
4.39
4.57
amide (LDA)23 and treated with tributyltin chloride to
give 9, but all the attempts made to purify 9 by silica
gel chromatography failed, due to a destannylation
reaction affording the starting material 8. Thus, the
reaction mixture of 9 was reacted with the Mn complex
2 and afforded the dinuclear complex 10 in 25% yield
for the two steps. Complex 10 reacted with triphenyl-
carbenium tetrafluoroborate, CPh3+BF4-, to deliver 11
quantitatively. No problem of stability during the reac-
tion occurred.
A second method described in Scheme 7 was devel-
oped in order to increase the yield of preparation of 11.
Thus, a Stille reaction with the chloro Mn complex 2
and 2-(tributylstannyl)-5-bromothiophene 12 in the
presence of Pd2dba3 and AsPh3 delivered complex 13 in
48% yield. Then, a Sonogashira reaction with ethynyl-
ferrocene 5 and 13 delivered the expected complex 10
in 78% yield, showing the efficiency of this method in
comparison with the first method.
Syn th esis of Com p lex 20. We then turned our
attention to the synthesis of 20, containing a spacer
homologated by a further triple bond. To achieve this
goal, we undertook a Sonogashira reaction with ethyn-
ylferrocene 5 and 2,5-dibromothiophene 14, and two
compounds were obtained: the desired one, 15, in 53%
yield and the bis(ferrocene) derivative 16 as a byproduct
(Scheme 8). Clearly, a competing reaction occurred
between the two bromo derivatives 14 and 15.
Nevertheless, using an excess of 2,5-dibromothiophene,
it was possible to minimize the formation of the bis-
(ferrocene) derivative 16. Moreover, the electron-donat-
ing ability of the ferrocenyl unit of complex 15 inhibits
the oxidative addition of Pd into the C-Br bond of this
δ(H2) - δ(H3)
C5H4 (2Ha)
C5H4 (2Hb)
complex with respect to the C-Br bond of the thiophene
derivative 14, avoiding the appearance of 16. A second
coupling reaction with (trimethylsilyl)acetylene and
complex 15 afforded complex 17 almost quantitatively.
This product was treated with NaOH in MeOH, yield-
ing, again quantitatively, complex 18 (Scheme 9).
Finally, a coupling reaction between 18 and the η5-Mn
complex 2 afforded in 48% yield the heterodinuclear
complex 19, from which hydrogen abstraction proceeded
quantitatively, giving the dinuclear complex 20.
NMR Sp ectr oscop y. Selected 1H NMR data, re-
ported in Table 2, showed that for the six-membered-
ring protons only H2 protons are influenced by the
nature of the spacer, with a maximum effect for the
linker containing a triple bond and a thiophenyl unit
(complex 11). Indeed, the H2 proton of 11 is the most
deshielded and exhibits the largest difference of chemi-
cal shifts δ(H2) - δ(H3) ) 0.95 ppm in comparison with
7 (0.73 ppm) and 20 (0.80 ppm). The chemical shifts of
the C5H4 ring protons of 11 and 20 have roughly the
same values (4.39 and 4.58 ppm for 11 and 4.39 and
4.57 ppm for 20), but they are shielded with respect to
those of 7 (4.46 and 4.64 ppm).
Selected 13C NMR data are reported in Table 3. The
carbonyl carbon resonance signals of complexes 7, 11,
and 20 at 216.0, 216.0, and 215.7 ppm are not arranged
according to decreasing donating ability24 but present
(24) (a) Gansow, O. A.; Schexnayder, D. A.; Kimura, B. Y.; J . Am.
Chem. Soc. 1972, 94, 3406-3408. In the case of Cr complexes, see:
(b) Van Meurs, F.; Baas, J . M. A.; Van Bekkum, H. J . Organomet.
Chem. 1976, 113, 353-359.
(23) Ewbank, P. C.; Nuding, G.; Suenaga, H.; McCullough, R. D.;
Shinkai, S. Tetrahedron Lett. 2001, 42, 155-158.

(η6-Arene)tricarbonylmanganese Linked to Ferrocenes
Organometallics, Vol. 23, No. 2, 2004 189
Ta ble 3. Selected 13C NMR Da ta (p p m )
in 20 because of the direct attachment of the thiophene
substituent on the cationic arene complex. Thus, the
alkynes serve as electronically conducting links, but a
relatively small amount of charge delocalization occurs,
while direct attachment of the π-excessive heterocycle
causes substantial transfer of positive charge to the
thiophene, but not onto the ferrocene.
complexa
entry
carbon
7e
11f
20g
1
2
3
4
5
6
7
8
C1
C2
C3
95.8
105.2
83.9
21.3
148.3
91.8
77.8
14.0
70.8
97.8
100.0
83.6
16.4
148.3
101.5
77.7
23.8
b
96.3
105.7
83.6
δ(C2) - δ(C3)
C4
Câ
CR
δ(Câ) - δ(CR)
Cp
22.1
149.2
86.8h
77.9i
11.7
IR Sp ectr oscop y. Complexes 7, 11, and 20 present
two CO stretching modes in accordance with the local
symmetry C3v due to the A1 and E bands of the Mn-
(CO)3 groups.26 The lowest frequencies of the Mn-CO
unit are observed in the case of complexes 7 and 11 at
2012 and 2077 cm-1 and at 2015 and 2073 cm-1
respectively, showing a better overall electron-donating
influence of the 1-(ferrocenylethynyl)-(4-methoxyben-
zene)thiophene and 2-(ferrocenylethynyl-5-(4-methoxy-
benzene)thiophene units as compared to that of complex
20 (2024 and 2080 cm-1) (see the Experimental Section).
The νas E band of the vibrationally coupled Mn-CO
stretching modes contains two degenerate antisymmet-
ric modes and so is combined with the νs A1 band in the
ratio 2:1 to calculate an estimate of the overall band
position that can be related to the degree of positive
charge on the metal, and the extent of back-donation of
electron density into the π* antibonding orbital of each
CO ligand. The values obtained in this way (weighted
mean band positions: 7, 2034 cm-1; 11, 2034 cm-1; 20,
2043 cm-1) show that complex 20 has substantially
more positive charge at the (arene)Mn(CO)3 end than
the other two compounds, which are quite similar to one
another.
c
d
9
10
70.6
CO
216.0
216.0
215.7
a
b
[D6]Me2CO at 29.55 ppm. 70-74 ppm, broad band. c Câ,
d
alkyne carbon â to C5H4FeCp. CR, alkyne carbon R to C5H4FeCp.
e For the atom numbering, see Scheme 5. f For the atom number-
g
h
ing, see Scheme 6. For the atom numbering, see Scheme 9. Or
i
77.9 or 85.6 or 89.6 ppm. Or 85.6 or 86.8 or 89.6 ppm.
similar values and seem to be independent of the nature
of the spacer (Table 3, entry 10). In fact, these signals
appear at almost the same frequency as (4-methoxy-
anisole)tricarbonylmanganese(I) tetrafluoroborate (216.7
ppm)11i and (anisole)tricarbonylmanganese(I) tetra-
fluoroborate (216.2 ppm),9a whereas for an arene sub-
stituted by a withdrawing group, for example (phenyl-
benzoate)tricarbonylmanganese tetrafluoroborate, the
carbonyl carbon resonance is at lower frequency: 213.0
ppm.8,22 These last data are in good agreement with the
fact that if the chemical shifts of the carbonyl carbon
nuclei increase, the CO ligands should be deshielded
with increasing electron richness of the metal center.25
Two important features, however, can be emphasized.
First, the 100.0 ppm resonance of the C2 carbon of
complex 11 occurs at a lower value than those of
complexes 7 and 20 (Table 3, entry 2). The overall
shielding effect on this carbon is unexpected, suggesting
a stronger electron donation of the spacer. The second
point concerns the unexpected chemical shift of the
carbon Câ (â to the ferrocenyl unit) of complex 11 at
101.5 ppm (Table 3, entry 6) with respect to the 91.8
ppm value of the carbon Câ of complex 7. The carbons
CR of complexes 7 and 11 resonate at 77.8 and 77.9 ppm.
The downfield shift of the Câ carbon (101.5 ppm for 11)
can be plausibly rationalized by a less efficient overall
electronic back-donation. It is also significant that the
largest difference of chemical shifts δ(Câ) - δ(CR) (Table
3, entry 8) is observed in the case of complex 11. This
corresponds also to the largest difference of chemical
shifts for the H2 and H3 protons of complex 11 (see Table
UV-Vis Sp ectr oscop y. The electronic spectra were
recorded in dichloromethane, chloroform, and acetoni-
trile. The longest wavelength absorptions of 7 at 470
nm (CH3CN), 494 nm (CH2Cl2), and 493 nm (CHCl3)
have small extinction coefficients and are assigned to
the metal to ligand charge transfer (MLCT) band arising
from a charge transfer from the manganese center to
the π- and σ-bound ligands.4,27 The next band at 302
nm (CH3CN), 310 nm (CH2Cl2), and 314 nm (CHCl3) has
an intense absorption and arises from intraligand (IL)
transitions with a high oscillator strength to the most
extent from π-π* transitions. These assignments are
supported by the moderate negative solvatochromism
of the MLCT band, which indicates that the electronic
ground state is more polar than the first excited state
(an increase in solvent polarity causes a hypsochromic
shift).28 This is also in agreement with the highly polar
nature of the cationic (η6-arene)tricarbonylmanganese
complexes, which can be attributed to the dominant µz-
dipole vector component directed from the arene to the
manganese carbonyl tripod (Figure 4). The π-π* transi-
tion intraligand charge transfer (ILCT) detected along
the µx-dipole axis are also shifted hypsochromically upon
an increase in solvent polarity, which reflects the
polarizability of 7. A canonical resonance structure of
the dinuclear complex 7 can be represented by a
cumulene structure with a cationic iron atom and a
neutral manganese atom (Figure 5).
1
2), and since the H and 13C NMR data of complexes 7
and 20 are very similar, this reveals the unique role of
the thiophene unit in 11.
The 13C NMR chemical shifts of Cp ligands are also
often taken as a guide to the degree of cationic character
of an FeCp moiety, and for complex 20, the position of
the Cp resonance is similar to that of complex 7. The
extent of electron donation from the ferrocene substitu-
ent should thus be similar in both cases. The electron
donation is delocalized through the extended π system
of 20, attenuating the effect on the cationic metal
complex (compared to the result in 7). In 11, the positive
charge on the Mn(CO)3 moiety is significantly less than
(26) (a) Davison, G.; Riley, E. M. Spectrochim. Acta 1971, 27A, 1649.
(b) Van Meurs, F.; Baas, J . M. A.; Van Bekkum, H. J . Organomet.
Chem. 1976, 113, 353-359.
(27) Kanis, D. R.; Ratner, M. A.; Marks, J . M. J . Am. Chem. Soc.
1992, 114, 10338-10357.
(25) In the case of Cr complexes, see ref 4b and: Mu¨ller, T. J . J .;
Lindner, H. J . Chem. Ber. 1996, 129, 607-613.
(28) Paley, M. S.; Harris, J . M. J . Org. Chem. 1989, 54, 3774-3778.

190 Organometallics, Vol. 23, No. 2, 2004
J acques et al.
electron density through alkyne links. Alkyne links
allow electronic communication but retain ground-state
charge separation between the ends of the bimetallic
molecule.
Exp er im en ta l Section
All reactions and manipulations were routinely performed
under a dry nitrogen atmosphere using Schlenk tube tech-
niques. THF was dried over sodium benzophenone ketyl and
distilled. Infrared spectra were measured on a Perkin-Elmer
1420 spectrometer. 1H and 13C{1H} NMR spectra were ob-
tained on Bruker AC200 and AC400 spectrometers. Elemental
analyses were performed by Le service de Microanalyses de
l’Universite´ Pierre et Marie Curie. UV-vis spectra were
recorded on a UVIKON 923 spectrometer and mass spectra
on a MALDI-TOF spectrometer. X-ray analysis: intensity data
were collected at room temperature on an Enraf-Nonius CAD4
diffractometer using Mo KR radiation. Accurate cell dimen-
sions and orientation matrixes were obtained from least-
squares refinements of the setting angles of 25 well-defined
reflections. No significant decay in the intensities of two
standard reflections was observed during the course of the data
collections. Crystal data, collection parameters, and other
significant details are listed in the Supporting Information.
The usual corrections for Lorentz and polarization effects were
applied. Computations were performed by using CRYSTALS.18a
Scattering factors and corrections for anomalous dispersion
were taken from ref 18b. The structures were resolved by direct
methods19 and refined by least squares with anisotropic
thermal parameters for all non-hydrogen atoms, excluding the
free BF4- anion. Hydrogen atoms were introduced in calculated
positions, and only one overall isotropic displacement param-
eter was refined.
F igu r e 4. Additive nature of ground-state dipole vectors
of carbonylmetal arenes with conjugated side chains.
F igu r e 5. Mesomeric forms of complex 7.
However, the X-ray structure data show clear alter-
nating single- and triple-bond character in the three
bonds of the link, thus reinforcing the assignment of
an electronic ground state with alkyne, not cumulene,
form. This crystal structure reveals that outward exten-
sion of the hapto-bound portions of the ligand to include
contributions from exo-methylenecyclopentadiene (ful-
vene) and exo-methylenecyclohexadienyl bonding modes
is not favored in the ground state, providing an illustra-
tion of the capacity of alkyne links to separate the
charged and neutral metal complexes. The ILCT transi-
tions and solvatochromic behavior observed in the UV
spectrum, however, provide evidence for retained elec-
tronic communication through the π system.
The corresponding UV-vis bands for complex 11 (475
nm in CH3CN, 481 nm in CH2Cl2, and 493 nm in CHCl3)
are similarly assigned to MLCT transitions and show
similar solvatochromism with a significant shift between
CH3CN and the less polar chlorinated solvents. The
degree of solvatochromism in the MLCT transitions of
complex 20 was less pronounced (470 nm in CH3CN,
480 nm in CH2Cl2, and 475 nm in CHCl3). The ILCT
transitions for the two complexes lie in the expected
range (11, 344 nm in CH3CN, 352 nm in CH2Cl2, and
352 nm in CHCl3; 20, 349 nm in CH3CN, 359 nm in
CH2Cl2, and 357 nm in CHCl3).
P r ep a r a tion of 1-(fer r ocen yleth yn yl)[η5(1-5)-4-m eth -
oxycycloh exa -2,4-d ien yl]t r ica r b on ylm a n ga n ese (I) (6).
Tris(dibenzylideneacetone)dipalladium (Pd2(dba)3; 51 mg, 0.56
mmol), triphenylarsine (51 mg, 0.168 mmol), and ethynylfer-
rocene (5;16 117 mg, 0.559 mmol) were introduced in a flask.
(η5-1-Chloro-4-methoxycyclohexa-2,4-dienyl)tricarbonylman-
ganese (2;8 158 mg, 0.559 mmol) was dissolved in NEt3 (16
mL) and poured via a cannula into the flask. The reaction
mixture was heated for 22 h at 40 °C with magnetic stirring.
Filtration of the mixture on Celite and evaporation of the
solution under reduced pressure gave a crude mixture which
was purified on a silica gel chromatography column (petroleum
ether/ether: 100/0 to 98/2). A red oil of 6 is obtained (198 mg,
0.434 mmol) in 78% yield. For C21H17FeMnO4, Mr ) 455.7. 1H
2
NMR (200 MHz, CDCl3): δ 2.46 (d, J ) 12.5 Hz, 1H, H6exo),
2
3
3
2.94 (dd, J ) 12.5 Hz, J ) 5 Hz 1H, H6endo), 3.05 (dd, J ) 6,
4J ) 2.5, 1H, H5), 3.46 (s, 3H, OMe), 4.17 (m, 2H, C5H4), 4.20
(s, 5H, C5H5), 5.15 (d, 3J ) 5.5, 1H, H2), 5.75 (dd, 3J ) 5.5,
4J ) 2.5 Hz, 1H, H3). 13C NMR (50 MHz, CDCl3): δ 32.1 (C6),
36.1 (C5), 49.4 (C1), 54.4 (OMe), 65.1 (C9), 67.4 (C3), 68.8 (C10
or C11), 70.1 (C12), 71.4 (C10 or C11), 85.2 (C7 or C8), 86.1 (C7 or
C8), 96.3 (C2), 143.2 (C4), 222.6 (CO). UV (CH3CN): λ 307 nm
(ꢀ ) 10 500 L mol-1 cm-1), λ 267 nm (ꢀ ) 13 700 L mol-1 cm-1).
UV (CH2Cl2): λ 311 nm (ꢀ ) 11 600 L mol-1 cm-1), λ 274 nm
(ꢀ ) 9547 L mol-1 cm-1). IR (CHCl3): νj 1951 cm-1 (Mn(CO)3),
2018 cm-1 (Mn(CO)3), 2201 cm-1 (CC). MS (MALDI-TOF,
m/z): calcd for C22H17FeMnO4, 455.98; found, 455.98 [M]+.
P r ep a r a tion of 1-(fer r ocen yleth yn yl)[η6(1-6)-4-m eth -
oxyb en zen e]t r ica r b on ylm a n ga n ese(I) Tet r a flu or ob o-
r a te (7). Complex 6 was dissolved in dichloromethane (6 mL)
(0.198 g, 0.434 mmol; 1 equiv). In another flask, triphenylcar-
benium tetrafluoroborate, CPh3BF4 (172 mg, 0.521 mmol; 1.2
equiv), was dissolved in CH2Cl2 (5 mL). This solution was
transferred via a cannula into the first flask and stirred for 1
h at room temperature with magnetic stirring. Freshly distilled
Et2O was added (40 mL): a precipitate formed. A red solid
was recovered after filtration on a frit to afford 7 (216 mg,
Con clu sion
We successfully developed a bimetallic Pd/Mn activa-
tion of carbon-chlorine bonds for the preparation of the
first heterodinuclear Fe/Mn complexes involving a fer-
rocenyl unit conjugated to a cationic (η6-arene)tricar-
bonylmanganese derivative. The (η5-1-chlorocyclohexa-
dienyl)tricarbonylmanganese starting material permits
the creation of a carbon-carbon bond at the C1 carbon.
Despite the presence of a ferrocenyl group in the
-
bimetallic complex, hydride abstraction by CPh3+BF4
yields efficiently the corresponding cationic (η6-arene)-
tricarbonylmanganese complexes. These complexes have
been studied in solution by different spectroscopic
methods in order to explore the extent of electron
transfer from one metal to the other and in the solid
state by an X-ray structure of complex 7, which provides
further indications of pathways for delocalization of

(η6-Arene)tricarbonylmanganese Linked to Ferrocenes
Organometallics, Vol. 23, No. 2, 2004 191
0.399 mmol; 92%). Slow recrystallization from a petroleum
ether/acetone mixture gave crystals (orthorhombic blocks, mp
143 °C) for an X-ray study. For C22H16BF4FeMnO4, Mr ) 541.8.
1H NMR (200 MHz, acetone-d6): δ 4.23 (s, 3 H, OMe), 4.30 (s,
5 H, Cp), 4.46 (m, 2 H, H10 or H11), 4.64 (m, 2 H, H10 or H11),
6.62 (d, 3J ) 7.5 Hz, 2 H, H3,5), 7.35 (d, 3J ) 7.5 Hz, 2 H, H2,6).
13C NMR (100 MHz, acetone-d6): δ 58.8 (OMe), 61.7 (C9), 70.8
(Cp), 70.9 (C10 or C11), 72.8 (C10 or C11), 77.8 (C8), 83.9 (C3,5),
91.8 (C7), 95.8 (C1), 105.2 (C2,6), 148.3 (C4), 216.0 (CO). UV
(CH3CN): λ 470 nm (ꢀ ) 1400 L mol-1 cm-1), λ 302 nm (ꢀ )
11 700 L mol-1 cm-1), λ 268 nm (ꢀ ) 14 400 L mol-1 cm-1). UV
(CH2Cl2): λ 494 nm (ꢀ ) 2000 L mol-1 cm-1), λ 310 nm (ꢀ )
12 400 L mol-1 cm-1), λ 269 nm (ꢀ ) 10 500 L mol-1 cm-1). UV
(CHCl3): λ 493 nm (ꢀ ) 1800 L mol-1 cm-1), λ 314 nm (ꢀ )
10 400 L mol-1 cm-1), λ 272 nm (ꢀ ) 9400 L mol-1 cm-1). IR
(CHCl3): νj 2012 cm-1 (Mn(CO)3+), 2077 cm-1 (Mn(CO)3+), 2213
cm-1 (CC). MS (MALDI-TOF, m/z): calcd for C22H16FeMnO4,
454.98; found, 454.98 [M - BF4]+. Anal. Calcd for C22H16BF4-
FeMnO4: C, 48.76; H, 2.98; Found: C, 48.29; H, 3.11.
Syn th esis of 2-(F er r ocen yleth yn yl)th iop h en e (8). Eth-
ynylferrocene (5; 210 mg, 1 mmol; 1 equiv), trans-dichlorobis-
(triphenylphosphine)palladium (PdCl2(PPh3)2; 35 mg, 0.05
mmol; 0.05 equiv), and copper(I) iodide (CuI; 10 mg, 0.05 mmol;
0.05 equiv) were dissolved in tetrahydrofuran (THF; 7 mL) and
triethylamine (NEt3; 7 mL). 2-Bromothiophene (0.107 mL, 1.1
mmol; 1.1 equiv) was added. The reaction mixture was heated
for 2 h under reflux. The reaction mixture was cooled to room
temperature and filtered on Celite. The solvents were removed
under reduced pressure, and the residue was purified by silica
gel chromatography column with petroleum ether. The orange
solid 8 (185 mg, 0.634 mmol) was obtained in 64% yield and
solution was transferred via a cannula into the flask and
stirred at room temperature for 15 h and for 1 h at room
temperature. Distilled water (20 mL) and Et2O (20 mL) were
added. The organic phase was extracted three times with Et2O
(20 mL). The organic phases were washed five times with
distilled water (20 mL), dried over magnesium sulfate, and
filtered on Celite, and the solvents were evaporated under
reduced pressure. The crude material was purified on a silica
gel chromatography column with petroleum ether/Et2O (100/0
to 98/2) as eluent, which afforded the orange compound 10
(0.086 g, 0.160 mmol; 25% in two steps). For C26H19FeMnO4S
Mr ) 537.8. 1H NMR (200 MHz, CDCl3): δ 2.57 (d, 2J ) 12
3
4
Hz, 1 H, H6′exo), 3.14 (dd, J ) 6 Hz, J ) 2 Hz, 1 H, H5′), 3.23
2
3
(dd, J ) 12 Hz, J ) 6 Hz, 1 H, H6′endo), 3.51 (s, 3 H, OMe),
4.23 (m, Cp or C5H4), 4.58 (m, 2 H, C5H4), 5.26 (d, 3J ) 5.5 Hz,
3
4
1 H, H2′), 5.79 (dd, J ) 5.5 Hz, J ) 2 Hz, 1 H, H3′), 6.65 (d,
3J ) 3.5 Hz, 1 H, Hthio), 7.00 (d, J 3 ) 3.5 Hz, 1 H, Hthio). 13C
NMR (50 MHz, CDCl3): δ 30.3 (C6′), 36.9 (C5′), 54.5 (OMe),
62.2 (C1′ or C5H4 quat), 64.7 (C5H4 quat or C1′), 65.9 (C3′), 69.1
(C5H4), 70.1 (Cp), 71.4 (C5H4), 78.9 (CC), 90.9 (C2′), 93.7 (CC),
122.2 (C3 or C4), 123.1 (Cthio,quat), 131.9 (C4 or C3), 143.2 (C4′),
146.6 (Cthio,quat), 222.0 (CO). UV (CH3CN): λ 370 nm (ꢀ ) 16 270
L mol-1 cm-1), λ 269 nm (ꢀ ) 14 255 L mol-1 cm-1). UV (CH2-
Cl2): λ 377 nm (ꢀ ) 16 100 L mol-1 cm-1), λ 265 nm (ꢀ ) 15 900
L mol-1 cm-1). UV (CHCl3): λ 377 nm (ꢀ ) 15 600 L mol-1
cm-1), λ 265 nm (ꢀ ) 16 400 L mol-1 cm-1). IR (CHCl3): νj 1943
cm-1 (Mn(CO)3), 2017 cm-1 (Mn(CO)3), 2208 cm-1 (CC).
Alter n a tive Syn th esis of 2-(F er r ocen yleth yn yl)-5-[η5-
(1′-5′)-(4′-m eth oxycycloh exa-2′,4′-dien yl)tr icar bon ylm an -
ga n ese(I)]th iop h en e (10). In a flask, a solution of diisopro-
pylamine (4 mL, 28.4 mmol; 1.1 equiv) in THF (15 mL) was
cooled to -78 °C, n-butyllithium (17.75 mL, 28.4 mmol; 1.1
equiv) was added, and the solution was stirred for 15 min at
-78 °C. In another flask, 2-bromothiophene (2.5 mL, 25.8
mmol; 1 equiv) in THF (15 mL) was cooled to -78 °C. LDA
was transferred into the other flask via a cannula, and after
the solution was stirred for 1 h, ClSnBu3 was added (7.7 mL,
28.4 mmol; 1.1 equiv). The solution was stirred for 1 h at -78
°C and 1 h at room temperature. Et2O (20 mL) and saturated
Na2CO3 (20 mL) were added. The solution was extracted three
times with saturated Na2CO3 (20 mL) and with water (20 mL).
The organic phase was dried over magnesium sulfate, filtered
on Celite, and evaporated under reduced pressure, giving
2-bromo-5-(tributylstannyl)thiophene (12) as a yellow liquid
in quantitative yield (11.66 g, 25.82 mmol). For C16H29BrSSn
used without further purification for the next step. For C16H12
-
1
FeS Mr ) 291.9. H NMR (200 MHz, CDCl3): δ 4.23 (s, 5 H,
3
Cp), 4.25 (m, 2 H, Cp), 4.49 (m, 2 H, Cp), 6.97 (dd, J ) 5 Hz,
3J ) 3.5 Hz, 1 H, H4), 7.22 (m, 2 H, H3 and H5). 13C NMR (100
MHz, CDCl3): δ 63.7 (C5H4 quat), 68.0 (C5H4), 69.0 (C5H5), 70.4
(C5H4), 77.7 (CCthio), 91.3 (CC), 123.1 (C2), 125.4 (C3 or C5),
126.0 (C5 or C3), 130.1 (C4).
Syn t h esis of 2-(F er r ocen ylet h yn yl)-5-(t r ib u t ylt in )-
th iop h en e (9). In a flask a solution of diisopropylamine (0.124
mL, 0.873 mmol; 1.3 equiv) in THF (2 mL) was cooled to -78
°C, and then n-butyllithium (0.582 mL, 0.873 mmol; 1.3 equiv)
was added and the mixture stirred for 15 min. In another flask,
compound 8 (0.196 g, 0.671 mmol; 1 equiv) was dissolved in
THF (4 mL) and cooled to -78 °C. Lithium diisopropylamide
(LDA) was transferred into the other flask via a cannula. The
reaction mixture was stirred for 1 h at -78 °C. Tributyltin
chloride (ClSnBu3; 0.200 mL, 0.738 mmol; 1 equiv) was added.
The reaction mixture was stirred for 1 h at -78 °C and at room
temperature for 1 h. The solution was extracted with Et2O (20
mL) and distilled water (20 mL). The organic phase was
washed twice with a saturated Na2CO3 solution (20 mL) and
then with water (20 mL). The organic phase was dried over
magnesium sulfate and filtered on Celite, and the solvents
were removed under reduced pressure. The orange oil 9 was
not purified because a carbon-tin cleavage occurred on silica
gel column chromatography. For C28H38FeSSn Mr ) 580.6. 1H
NMR (200 MHz, CDCl3): δ 0.78-1.89 (m, 27 H, Sn(Bu)3), 4.25
1
Mr ) 451.7. H NMR (200 MHz, CDCl3): δ 0.85-1.63 (m, 27
3
3
H, Sn(Bu)3), 6.91 (d, J ) 3.5 Hz, 1 H, H2 or H3), 7.13 (d, J )
3.5 Hz, 1 H, H2 or H3). 13C NMR (50 MHz, CDCl3): δ 11.0 (Bu),
13.8 (Bu), 27.4 (Bu), 29.0 (Bu), 116.4 (C1 or C4), 131.0 (C2 or
C3), 135.9 (C2 or C3), 139.6 (C1 or C4). In a flask (50 mL) was
introduced (η5-1-chloro-4-methoxycyclohexa-2,4-dienyl)tricar-
bonylmanganese (2; 0.282 mg, 1 mmol; 1 equiv), triphenylar-
sine (AsPh3; 46 mg, 0.15 mmol; 0.15 equiv), and tris(diben-
zylideneacetone)dipalladium (Pd2(dba)3; 46 mg, 0.05 mmol;
0.05 equiv) in DMF (5 mL). The mixture was heated for 10
min at 40 °C. In another flask, 2-bromo-5-(tributylstannyl)-
thiophene (12; 0.452 g, 1 mmol; 1 equiv) was dissolved in DMF
(5 mL). The solution was transferred into the other flask via
a cannula. The reaction mixture was heated to 40 °C for 1.5
h. After Et2O (20 mL) and distilled water (20 mL) were added,
the organic phase was recovered. The water phase was
extracted four times with ethyl acetate. Organic phases were
collected, washed with water, dried over MgSO4, and evapo-
rated under reduced pressure. Purification by silica gel column
chromatography with petroleum ether as eluent gave the
yellow solid 2-bromo-5-[η5(1-5)-4-methoxycyclohexa-2,4-di-
enyl)tricarbonylmanganese]thiophene (13; 0.198 g, 0.484 mmol)
3
(m, 7 H, Cp and C5H4), 4.50 (m, 2 H, C5H4), 7.04 (d, J ) 3.5
3
Hz, 1 H, H3), 7.34 (d, J ) 3.5 Hz, 1 H, H4).
Syn th esis of 2-(F er r ocen yleth yn yl)-5-[(η5(1′-5′)-4′-
m et h oxycycloh exa -2′,4′-d ien yl)t r ica r b on ylm a n ga n ese-
(I)]th iop h en e (10). Compound 9 used without purification
was introduced into a flask (50 mL) with a water cooler. On
the basis of the assumption that the yield of the preceding
reaction was quantitative, triphenylarsine (AsPh3; 39 mg,
0.127 mmol; 0.2 equiv) and tris(dibenzylideneacetone)dipal-
ladium (Pd2(dba)3; 29 mg, 0.032 mmol; 0.05 equiv) were
dissolved in DMF (5 mL). In another flask, (η5-1-chloro-4-
methoxycyclohexadienyl)tricarbonylmanganese (2; 0.179 mg,
0.634 mmol; 1 equiv) was dissolved in DMF (5 mL) and the
1
in 48% yield. For C14H10BrMnO4S Mr ) 408.9. H NMR (400
MHz, CDCl3): δ 2.54 (d, 2J ) 12 Hz, 1 H, H6′exo), 3.12 (dd,
4
2
3
3J ) 6 Hz, J ) 2 Hz, 1 H, H5′), 3.18 (dd, J ) 12 Hz, J ) 6
3
Hz, 1 H, H6′endo), 3.51 (s, 3 H, OMe), 5.17 (d, J ) 5.5 Hz, 1 H,

192 Organometallics, Vol. 23, No. 2, 2004
J acques et al.
3
4
3
H2′), 5.77 (dd, J ) 5.5 Hz, J ) 2 Hz, 1 H, H3′), 6.53 (d, J )
69.0 (Cp), 70.4 (C5H4), 76.8 (CC), 92.6 (CC), 110.9 (Cthio,quat),
124.9 (Cthio,quat), 128.9 (Cthio), 130.6 (Cthio). The minor product
16 was obtained, but only a 1H NMR spectrum of the crude
material has been recorded. In a flask (50 mL), the bro-
mothiophene 15 (0.210 g, 0.566 mmol; 1 equiv) and trans-
dichlorobis(triphenylphosphine)palladium (PdCl2(PPh3)2; 20
mg, 0.028 mmol; 0.05 equiv) and CuI (6 mg, 0.028 mmol; 0.05
equiv) were dissolved in THF (7 mL) and NEt3 (7 mL).
(Trimethylsilyl)acetylene (0.120 mL, 0.849 mmol; 1.5 equiv)
was added and the reaction mixture heated under reflux with
magnetic agitation for 3 h. The reaction mixture was filtered
on Celite, and the solvents were evaporated under reduced
pressure. The crude product was purified by silica gel column
chromatography with petroleum ether as eluent. The orange
solid 17 (0.220 g, 0.566 mmol) was obtained quantitatively.
For C21H20FeSSi Mr ) 388.0. 1H NMR (200 MHz, CDCl3): δ
0.24 (s, 9 H, Si(Me)3), 4.24 (s, 5 H, Cp), 4.25 (m, 2 H, C5H4),
3.5 Hz, 1 H, Hthio), 6.85 (d, J ) 3.5 Hz, 1 H, Hthio). 13C NMR
3
(50 MHz, CDCl3): δ 30.2 (C6′), 36.8 (C5′), 54.5 (OMe), 61.6 (C1′),
65.7 (CH, C3′), 90.8 (C2′), 111.0 (C5), 122.4 (C3 or C4), 130.5 (C4
or C3), 143.2 (C4′), 147.5 (C2), 222.5 (CO). IR (CHCl3): νj 1943
cm-1 (Mn(CO)3), 2016 cm-1 (Mn(CO)3). In a flask (50 mL),
2-bromo-5-[η5(1-5)-4-methoxycyclohexa-2,4-dienyl)tricarbon-
ylmanganese]thiophene (13; 0.198 g, 0.484 mmol; 1 equiv),
trans-dichlorobis(triphenylphosphine)palladium (PdCl2(PPh3)2;
17 mg, 0.024 mmol; 0.05 equiv), and copper(I) iodide (CuI; 5
mg, 0.024 mmol; 0.05 equiv) were dissolved in THF (2 mL)
and triethylamine NEt3 (5 mL). The reaction mixture was
heated under reflux for 10 min. In another flask, ethynylfer-
rocene (0.112 g, 0.532 mmol; 1.1 equiv) was dissolved in THF
(3 mL). The solution was transferred via a cannula and stirred
for 30 min. The solution was filtered on Celite and the solvent
evaporated under reduced pressure. The residue was purified
3
by silica gel column chromatography with
petroleum ether and ether (100/0 to 98/2). The orange powder
10 (0.203 g, 0.378 mmol) was obtained in 78% yield.
a mixture of
4.49 (m, 2 H, C5H4), 7.01 (d, J ) 3.5 Hz, 1 H, Hthio), 7.07 (d,
3J ) 3.5 Hz, 1 H, Hthio). 13C NMR (100 MHz, CDCl3): δ 0.0
(SiMe3), 64.4 (Cquat C5H4), 69.4 (C5H4), 70.3 (Cp), 71.7 (C5H4),
78.6 (CC), 93.7 (CC), 97.3 (CC), 99.8 (CC), 123.7 (Cthio,quat),
125.8 (Cthio,quat), 131.0 (Cthio), 132.7 (Cthio). Compound 17 (0.220
g, 0.566 mmol; 1 equiv) was dissolved in MeOH (15 mL). A
solution of sodium hydroxide (0.670 mL, c ) 2 N; 2.2 equiv)
was then added. The reaction mixture was stirred at room
temperature for 3 h and extracted with water and Et2O. The
organic phase was washed with a saturated solution of NaCl,
dried over MgSO4, and filtered on Celite. Evaporation of the
solvents under reduced pressure afforded quantitatively the
red oil 18 (0.179 g, 0.566 mmol). For C28H12FeS Mr ) 315.9.
1H NMR (200 MHz, CDCl3): δ 3.37 (s, 1 H, CCH), 4.25 (m, 7
H, Cp, C5H4), 4.51 (m, 2 H, C5H4), 7.04 (d, 3J ) 4 Hz, 1 H,
Syn t h esis of 2-(F er r ocen ylet h yn yl)-5-{[η6(1-6′)-(4′-
m eth oxyben zen e)]tr icar bon ylm an gan ese}th ioph en e Tet-
r a flu or obor a te (11). In a flask, 10 (0.198 g, 0.434 mmol; 1
equiv) was dissolved in dichloromethane (6 mL). In another
flask, triphenylcarbenium tetrafluoroborate (CPh3BF4; 0.172
g, 0.521 mmol; 1.2 equiv) was dissolved in dichloromethane
(5 mL). This solution was transferred into the first flask via a
cannula and stirred for 30 min at room temperature. Freshly
distilled diethyl ether (40 mL) was introduced into the
medium, and an orange precipitate formed, affording 11 in
92% yield (216 mg, 0399 mmol). Mp: 129 °C. For C26H18BF4-
FeMnO4S Mr ) 536.99. 1H NMR (200 MHz, acetone-d6): δ 4.22
(s, 3 H, OMe), 4.28 (s, 5 H, Cp), 4.39 (m, 2 H, C5H4), 4.57 (m,
H
thio), 7.13 (d, 3J ) 4 Hz, 1 H, Hthio). 13C NMR (50 MHz,
3
3
CDCl3): δ 64.2 (C5H4 Cquat), 69.3 (C5H4), 70.2 (Cp), 71.6 (C5H4),
78.3 (CC), 82.0 (CCH), 93.9 (CC), 122.3 (Cthio,quat), 126.1
(Cthio,quat), 130.8 (Cthio), 133.1 (Cthio). (η5-1-Chloro-4-methoxy-
cyclohexadienyl)tricarbonylmanganese (2; 0.134 mg, 0.472
mmol; 1 equiv), triphenylarsine (AsPh3; 29 mg, 0.094 mmol;
0.20 equiv), and tris(dibenzylideneacetone)dipalladium (Pd2-
(dba)3; 22 mg, 0.024 mmol; 0.05 equiv) were introduced in a
flask. NEt3 (7 mL) was added. The reaction mixture was
heated at 40 °C for 10 min. In another flask, the acetylene
compound 18 (0.149 g, 0.472 mmol; 1 equiv) was dissolved in
NEt3 (8 mL). This solution was transferred into the first flask
via a cannula. The reaction mixture was stirred for 2 h at
40 °C and filtered on Celite, and the solvents were evaporated
under reduced pressure. A red oil was obtained, which was
purified by silica gel column chromatography (petroleum ether/
ether:100/0 to 90/10), giving compound 19 (0.128 g, 0.228
mmol) in 48% yield. For C28H19FeMnO4S Mr ) 561.8. 1H NMR
(200 MHz, CDCl3): δ 2.46 (d, 2J ) 13 Hz, 1 H, H6exo), 2.94 (dd,
2 H, C5H4), 6.63 (d, J ) 7.5 Hz, 2 H, H3,5), 7.35 (d, J ) 4 Hz,
3
3
1 H, Hthio), 7.43 (d, J ) 7.5 Hz, 2 H, H2,6), 7.48 (d, J ) 4 Hz,
1 H, Hthio). 13C NMR (100 MHz, acetone-d6): δ 58.9 (OMe),
70-74br (Cp and C5H4) (CC), 83.6 (C3,5), 97.8 (C1), 100.0 (C2,6),
101.5 (CC), 128.8 (Cthio quat), 130.0 (Cthio), 133.4 (Cthio), 134.3
(Cthio,quat), 148.7 (C4), 216.0 (CO). UV (CH2Cl2): λ 269 nm (ꢀ )
16 700 L mol-1 cm-1), λ 352 nm (ꢀ ) 21 300 L mol-1 cm-1), λ
481 nm (ꢀ ) 3400 L mol-1 cm-1). UV (CHCl3): λ 268 nm (ꢀ )
17 000 L mol-1 cm-1), λ 352 nm (ꢀ ) 20 800 L mol-1 cm-1), λ
493 nm (ꢀ ) 3300 L mol-1 cm-1). UV (CH3CN): λ 270 nm (ꢀ )
17 300 L mol-1 cm-1), λ 344 nm (ꢀ ) 23 300 L mol-1 cm-1), λ
475 nm (ꢀ ) 3100 L mol-1 cm-1). IR (CHCl3): νj 2015 cm-1 (Mn-
(CO)3+), 2073 cm-1 (Mn(CO)3), 2202 cm-1 (CC). IR (solid state):
νj 2020 cm-1 (Mn(CO)3+), 2068 cm-1 (Mn(CO)3+), 2360, 2341
cm-1 (CC). MS (MALDI-TOF, m/z): calcd for C26H18FeMnO4S,
536.99; found, 536.96 [M - BF4]+. Anal. Calcd for C26H18BF4-
FeMnO4S (Mr ) 623.97): C, 50.00; H, 2.91. Found: C, 49.31;
H, 2.96.
3
3
4
2J ) 13 Hz, J ) 6 Hz, 1 H, H6endo), 3.08 (dd, J ) 6 Hz, J )
Syn t h esis of 2-(F er r ocen ylet h yn yl)-5-{[η5(1′-5′)-(4′-
m eth oxycycloh exa -2′,4′-d ien yl)tr ica r bon ylm a n ga n ese]-
eth yn yl}th iop h en e (19). In a flask (50 mL) was added trans-
dichlorobis(triphenylphosphine)palladium (PdCl2(PPh3)2; 18
mg, 0.025 mmol; 0.05 equiv), and copper(I) iodide (CuI; 5 mg,
0.025 mmol; 0.05 equiv) was dissolved in THF (2 mL) and
triethylamine NEt3 (5 mL). 2,5-Dibromothiophene (14; 0.115
mL, 1 mmol; 2 equiv) was added and the reaction mixture
heated under reflux for 10 min. In another flask, ethynylfer-
rocene (5; 0.105 g, 0.5 mmol; 1 equiv) was dissolved in THF (3
mL) and transferred into the first flask via a cannula. The
mixture was stirred for 30 min under reflux. Filtration on
Celite and evaporation of the solvents under reduced pressure
gave a residue which was purified by silica gel column
chromatography (petroleum ether/ether: 100/0 to 90/0). A red
powder of 15 was obtained (0.099 g, 0.267 mmol) in 53% yield.
2.5 Hz, 1 H, H5), 3.46 (s, 3 H, OMe), 4.23 (s, 5 H, H18), 4.26
3
(m, 2 H, H16 or H17), 4.48 (m, 2 H, H16 or H17), 5.24 (d, J ) 6
3
4
Hz, 1 H, H2), 5.80 (dd, J ) 6 Hz, J ) 2.5 Hz, 1 H, H3), 6.98
3
3
(d, J ) 4 Hz, 1 H, H10 or H11), 7.01 (d, J ) 4 Hz, 1 H, H10 or
H
11). 13C NMR (50 MHz, CDCl3): δ 31.8 (C6), 36.5 (C5), 46.2
(C1), 54.5 (OMe), 64.4 (C15), 68.3 (C3), 69.2 (C16 or C17), 70.1
(C18), 71.5 (C16 or C17), 78.5 (CC), 78.9 (CC), 93.7 (CC), 94.8
(CC), 97.1 (C2), 123.7 (C9 or C12), 125.3 (C9 or C12), 131.0 (C10
or C11), 131.7 (C10 or C11), 143.3 (C4), 221.9 (CO). UV (CH3-
CN): λ 355 nm (ꢀ ) 27 700 L mol-1 cm-1), λ 264 nm (ꢀ ) 21 900
L mol-1 cm-1). UV (CH2Cl2): λ 358 nm (ꢀ ) 27 000 L mol-1
cm-1) UV (CHCl3): λ 358 nm (ꢀ ) 26 900 L mol-1 cm-1). IR
(CHCl3): νj 1948 cm-1 (Mn(CO)3), 2019 cm-1 (Mn(CO)3). MS
(MALDI-TOF, m/z): calcd for C28H19FeMnO4S, 561.97; found,
561.97 [M]+.
Syn t h esis of 2-(F er r ocen ylet h yn yl)-5-{[(η6(1′-6′)-4′-
m et h oxyp h en yl)t r ica r b on ylm a n ga n ese]et h yn yl}t h io-
p h en e Tetr a flu or obor a te (20). Compound 19 (0.057 g, 0.102
mmol; 1 equiv) was dissolved in dichloromethane (5 mL) in a
1
For C16H11BrFeS, Mr ) 370.8. H NMR (200 MHz, CDCl3): δ
4.23 (s, 5 H, Cp), 4.25 (m, 2 H, C5H4), 4.48 (m, 2 H, C5H4),
3
3
6.91 (d, J ) 4 Hz, 1 H, Hthio), 6.94 (d, J ) 4 Hz, 1 H, Hthio).
13C NMR (100 MHz, CDCl3): δ 63.2 (CquatC5H4), 68.1 (C5H4),

(η6-Arene)tricarbonylmanganese Linked to Ferrocenes
Organometallics, Vol. 23, No. 2, 2004 193
flask. In another flask triphenylcarbenium tetrafluoroborate
(CPh3BF4; 0.034 g; 0.102 mmol; 1 equiv) was dissolved in
dichloromethane (5 mL). This solution was transferred via a
cannula into the first flask. The reaction mixture was stirred
for 30 min, and freshly distilled Et2O was added. An orange
precipitate appeared and was collected by filtration to afford
20 (0.066 g, 0.102 mmol), obtained in quantitative yield. For
λ 264 nm (ꢀ ) 23 900 L mol-1 cm-1). UV (CHCl3): λ 475 nm
(ꢀ ) 3800 L mol-1 cm-1), λ 357 nm (ꢀ ) 28 400 L mol-1 cm-1),
λ 264 nm (ꢀ ) 24 600 L mol-1 cm-1). IR (CHCl3): νj 2024 cm-1
(Mn(CO)3+), 2080 cm-1 (Mn(CO)3+), 2248, 2200 cm-1 (CC). MS
(MALDI-TOF, m/z): calcd for C28H18FeMnO4S, 560.97; found,
560.90 [M - BF4]+. Anal. Calcd for C28H18BF4FeMnO4S (Mr )
647.97): C, 51.85; H, 2.80. Found: C, 51.71, H, 2.59.
C
28H18BF4FeMnO4S Mr ) 647.6. Mp: 151 °C. 1H NMR (200
MHz, acetone-d6): δ ) 4.24 (s, 3 H, OMe), 4.28 (s, 5 H, Cp),
Ack n ow led gm en t. We thank the COST D14 action
(WG008) and the CNRS for financial support and Prof.
C. Rolando and Dr. G. Ricart from the “Universite´ des
Sciences et Techniques de Lille” for MS analyses.
3
4.39 (m, 2 H, C5H4), 4.57 (m, 2 H, C5H4), 6.63 (d, J ) 7.5 Hz,
3
3
2 H, H3,5), 7.28 (d, J ) 4 Hz, 1 H, Hthio), 7.43 (d, J ) 7.5 Hz,
3
2 H, H2,6), 7.48 (d, J ) 4 Hz, 1 H, Hthio). 13C NMR (100 MHz,
acetone-d6): δ 59.0 (OMe), 64.0 (C15), 70.2 (C5H4), 70.6 (C18),
72.1 (C5H4), 77.9 (CC), 83.6 (C3,5), 85.6 (CC), 86.8 (CC), 89.6
(CC), 96.3 (C1), 105.7 (C2,6), 120.3 (Cthio,quat), 129.0 (Cthio,quat),
132.3 (Cthio), 136.3 (Cthio), 149.2 (C4), 215.7 (CO). UV (CH3-
CN): λ 470 nm (ꢀ ) 3100 L mol-1 cm-1), λ 349 nm (ꢀ ) 31 400
L mol-1 cm-1), λ 260 nm (ꢀ ) 13 400). UV (CH2Cl2): λ 480 nm
(ꢀ ) 4400 L mol-1 cm-1), λ 359 nm (ꢀ ) 27 300 L mol-1 cm-1),
Su p p or tin g In for m a tion Ava ila ble: Tables giving crys-
tal data, atomic coordinates, and bond distances and angles
and figures giving additional views of complex 7. This material
is available free of charge via the Internet at http://pubs.acs.org.
OM034168F