Study of ferrocenyl-substituted Co2(CO)6-bispropargylic alcohol complexes as substrates for the formation of chains and macrocycles

Article abstract of DOI:10.1016/j.jorganchem.2008.05.011

Treatment of [Fc-1-R¹-1′-R²] (R¹ = H, R² = CH(O); R¹ = H, R² = CMe(O); R¹ = R² = CMe(O)) with LiC{triple bond, long}CCH₂OLi (prepared in situ from HC{triple bond, long}CCH₂OH and n-BuLi) affords the ferrocenyl-substituted but-2-yne-1,4-diol compounds of general formula [Fc-1-R¹-1′-{CR(OH)C{triple bond, long}CCH₂OH}] (R¹ = R = H (1a); R¹ = H, R = Me (1b); R¹ = CMe(O), R = Me (1c)) in low to high yields, respectively (where Fc = Fe(η⁵-C₅H₄)₂). In the case of the reactions of [Fc-1-R¹-1′-R²] (R¹ = H, R² = CH(O); R¹ = R² = CMe(O)), the by-products [Fc-1-R¹-1′-{CR(OH)(CH₂)₃CH₃}] (R¹ = R = H (2a); R¹ = CMe(O), R = Me (2c)) along with minor quantities of [Fc-1,1′-{CMe(OH)(CH₂)₃CH₃}₂] (3) are also isolated; a hydrazide derivative of dehydrated 2c, [1-(CMe{double bond, long}CHCH₂CH₂CH₃)-1′-(CMe{double bond, long}NNH-2,4-(NO₂)₂C₆H₃)] (2c′), has been crystallographically characterised. Interaction of 1 with Co₂(CO)₈ smoothly generates the alkyne-bridged complexes [Fc-1-R¹-1′-{Co₂(CO)₆-μ-η²-CR(OH)C{triple bond, long}CCH₂OH}] (R¹ = R = H (4a); R¹ = H, R = Me(4b); R¹ = CMe(O), R = Me (4c)) in good yield. Reaction of 4a with PhSH, in the presence of catalytic quantities of HBF₄ · OEt₂, gives the mono- [Fc-1-H-1′-{Co₂(CO)₆-μ-η²-CH(SPh)C{triple bond, long}CCH₂OH}] (5) and bis-substituted [Fc-1-H-1′-{Co₂(CO)₆-μ-η²-CH(SPh)C{triple bond, long}CCH₂SPh}] (6) straight chain species, while with HS(CH₂)_nSH (n = 2,3) the eight- and nine-membered dithiomacrocylic complexes [Fc-1-H-1′-{cyclo-Co₂(CO)₆-μ-η²-CH(S(CH₂)_n-)C{triple bond, long}CCH₂S-}] [n = 2 (7a), n = 3 (7b)] are afforded. By contrast, during attempted macrocyclic formation using 4b and HSCH₂CH₂OCH₂CH₂SH dehydration occurs to give [Fc-1-H-1′-{Co₂(CO)₆-μ-η²-C({double bond, long}CH₂)C{triple bond, long}CCH₂OH}] (8). Single crystal X-ray diffraction studies have been reported on 2c′, 4b, 4c, 7b and 8.

Full text of DOI:10.1016/j.jorganchem.2008.05.011

Journal of Organometallic Chemistry 693 (2008) 2683–2692
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Study of ferrocenyl-substituted Co2(CO)6-bispropargylic alcohol complexes
as substrates for the formation of chains and macrocycles
a
c,
Vladimir B. Golovko a,b, , Martin J. Mays , Gregory A. Solan
*
*
a Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, UK
b Department of Chemistry, Canterbury University, Private Bag 4800, Christchurch, New Zealand
c Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, UK
a r t i c l e i n f o
a b s t r a c t
Treatment of [Fc-1-R1-10-R2] (R1 = H, R2 = CH(O); R1 = H, R2 = CMe(O); R1 = R2 = CMe(O)) with LiC„C-
CH2OLi (prepared in situ from HC„CCH2OH and n-BuLi) affords the ferrocenyl-substituted but-2-yne-
1,4-diol compounds of general formula [Fc-1-R1-10-{CR(OH)C„CCH2OH}] (R1 = R = H (1a); R1 = H,
Article history:
Received 20 March 2008
Received in revised form 28 April 2008
Accepted 6 May 2008
R = Me (1b); R1 = CMe(O), R = Me (1c)) in low to high yields, respectively (where Fc = Fe( 5-C5H4)2). In
g
Available online 13 May 2008
the case of the reactions of [Fc-1-R1-10-R2] (R1 = H, R2 = CH(O); R1 = R2 = CMe(O)), the by-products [Fc-
1-R1-10-{CR(OH)(CH2)3CH3}] (R1 = R = H (2a); R1 = CMe(O), R = Me (2c)) along with minor quantities of
Keywords:
[Fc-1,10-{CMe(OH)(CH2)3CH3}2] (3) are also isolated;
a hydrazide derivative of dehydrated 2c,
Ferrocenyl
Nicholas reaction
Selectivity
Thiols
Linear chains
Macrocycles
[1-(CMe@CHCH2CH2CH3)–10-(CMe@NNH-2,4-(NO2)2C6H3)] (2c0), has been crystallographically character-
ised. Interaction of 1 with Co2(CO)8 smoothly generates the alkyne-bridged complexes [Fc-1-R1-10-
{Co2(CO)6-
good yield. Reaction of 4a with PhSH, in the presence of catalytic quantities of HBF4 ꢀ OEt2, gives the
mono- [Fc-1-H-10-{Co2(CO)6- g2–CH(SPh)C„CCH2OH}] (5) and bis-substituted [Fc-1-H-10-{Co2(CO)6-
2-CH(SPh)C„CCH2SPh}] (6) straight chain species, while with HS(CH2)nSH (n = 2,3) the eight- and
nine-membered dithiomacrocylic complexes [Fc-1-H-10-{cyclo-Co2(CO)6- 2-CH(S(CH2)n–)C„CCH2S–}]
[n = 2 (7a), n = 3 (7b)] are afforded. By contrast, during attempted macrocyclic formation using 4b and
HSCH2CH2OCH2CH2SH dehydration occurs to give [Fc-1-H-10-{Co2(CO)6- 2-C(@CH2)C„CCH2OH}] (8).
Single crystal X-ray diffraction studies have been reported on 2c0, 4b, 4c, 7b and 8.
Ó 2008 Elsevier B.V. All rights reserved.
l-g
2-CR(OH)C„CCH2OH}] (R1 = R = H (4a); R1 = H, R = Me(4b); R1 = CMe(O), R = Me (4c)) in
l-
l-g
l-g
l-g
1. Introduction
to a wide variety of alkyne-containing macrocycles incorporating
an assortment of donor groups [3b,3c–7].
The capacity of the Nicholas reaction to facilitate the substitu-
tion of dicobalt hexacarbonyl-coordinated propargylic alcohols
(and ethers) with a range of functional groups has proved a power-
ful and versatile tool in organic synthesis [1]. In general a Lewis
acid such as, HBF4 ꢀ OEt2, BF3 ꢀ OEt2 or trifluoromethane sulfonic
acid is used to promote the formation of a Co2(CO)6-stabilised
propargylic cation which can then undergo attack by the corre-
sponding nucleophile. In the same way, symmetrical Co2(CO)6-
monoynediols (A, Fig. 1) and {Co2(CO)6}2-diynediols can undergo
substitution reactions at both propargylic carbon centres to afford
linear chains [2,3]. On the other hand, use of such cobalt carbonyl-
coordinated diol substrates in combination with bifunctional
nucleophiles has led to the development of high yielding routes
Herein we report the preparation of a new family of unsymmet-
rical 1-ferrocenyl-substituted Co2(CO)6-but-2-yne-1,4-diol com-
pounds (4, Fig. 1), with a view to probing the ability of the
ferrocenyl substituent to modulate the acid-catalysed reactivity
of the independent propargylic centres towards thiol- and
dithiol-based nucleophiles. This synthetic investigation has, in
part, been stimulated by Reutov and Gruselle’s report (based on
NMR studies) of the aptitude of a ferrocenyl group in tandem with
an alkyne-bridged dicobalt hexacarbonyl unit to jointly influence
the stability of an adjacent carbocation [8]. Furthermore, effective
routes to systems of type 4 and its derivatives are of added interest
due to the presence of two organometallic functionalities that have
independently shown anti-cancer properties [9,10].
2. Results and discussion
2.1. Route to [Fc-1-R1-10-{CR(OH)C„CCH2OH}] (1)
* Corresponding authors. Address: Department of Chemistry, Lensfield Road,
Cambridge CB2 1EW, UK (V.B. Golovko). Tel.: +44 116 252 2096; fax: +44 116 252
3789 (G.A. Solan).
E-mail addresses: vladimir.golovko@canterbury.ac.nz (V.B. Golovko), gas8@
leicester.ac.uk (G.A. Solan).
Treatment of the dilithiated propargyl alcohol (prepared in situ
from the reaction of HC„CCH2OH with 2 equiv. of n-BuLi) with an
0022-328X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2008.05.011

2684
V.B. Golovko et al. / Journal of Organometallic Chemistry 693 (2008) 2683–2692
The mass spectra of 1a–1c all show molecular ions in addition
to peaks corresponding to M++Na ions. In their 13C NMR spectra,
the alkynic carbon atoms are seen in each case as separate singlets
in the range d 98.1–85.8, while the independent propargyl carbon
atoms appear more upfield (range: d 66.4–50.7) with the ferro-
cene-linked carbon displaying the more positive of the two chem-
ical shifts. The 1H NMR spectra for 1a–1c support the formulations
with the propargyl CH2 protons evident as doublets (1a, 1b) or as a
singlet (1c); the former multiplicity is the result of three-bond cou-
OH
OH
OH
OH
R
R
R
R
R
R
R
Fe
R1
Co2(CO)6
Co2(CO)6
A
4
Fig. 1. Symmetrical and unsymmetrical but-2-yne-1,4-diol-Co2(CO)6 complexes
[R = H, Me; R1 = H, CMe(O)].
pling to the hydroxyl proton. The proton at the carbon atom
a to
the ferrocene (i.e., FcCHOH) in 1a gives rise to a doublet at 5.21
(3JH–H 6.5 Hz) due to coupling to the OH proton, which is supported
by the presence of a mutually coupled doublet at d 3.42 for the hy-
droxyl proton itself.
equimolar quantity of ferrocenecarboxaldehyde in tetrahydrofuran
at ꢁ78 °C gave, on work-up, [Fc-1-H-10-{CH(OH)C„CCH2OH}] (1a)
as the major product and [Fc-1-H-10-{CH(OH)(CH2)3CH3}] (2a)
(Fc = Fe(g
5-C5H4)2) as the minor one, in good overall yield (Scheme
Compounds 2a and 3 have been reported previously [11,12],
while 2c has been assigned a related structure on the basis of a
comparison of its spectroscopic data with those of 2a and 3. Thus,
the mass spectrum of 2c revealed a M++Na peak while the IR and
13C NMR spectra were consistent with the presence of an unre-
acted acetyl moiety. In order to allow access to a crystalline sam-
ple, 2c was treated with H2NNH-2,4-C6H3(NO2)2 in ethanol, in
the presence of a catalytic amount of glacial acetic acid, to afford
the yellow crystalline derivative [Fc-1-(CMe@CHCH2CH2CH3)–10-
(CMe@NNH-2,4-(NO2)2C6H3)] (2c0) in high yield. Single crystals of
2c0 suitable for an X-ray diffraction study were grown from a hex-
1). Under similar reaction conditions, acetylferrocene afforded [Fc-
1-H-10-{CMe(OH)C„CCH2OH}] (1b) as the sole isolable product in
low yield (Scheme 1). In contrast, the attempted reaction of LiC„C-
CH2OLi with 1,10-diacetylferrocene in a 3:1 ratio gave, on work-up,
[Fc-1-{CMe(O)–10-{CMe(OH)(CH2)3CH3}] (2c) as the major product
and [Fc-1-{CMe(O)}-10-{CMe(OH)C„CCH2OH}] (1c) as the minor
product, along with trace quantities of [Fc-1,10-{CMe(OH)(CH2)3-
CH3}2] (3) (Scheme 1). All the new ferrocene-containing compounds
have been characterised by 1H and 13C NMR spectroscopy and ESI
mass spectrometry (Section 4). In addition, a hydrazide derivative
of 2c has been characterised by single crystal X-ray diffraction.
OH
OH
(i),(ii)
+
Fe
Fe
(R1 = H, R2 = CH(O))
OH
1a
2a
OH
R2
(i),(ii)
Fe
(R1 = H, R2 = CMe(O))
Fe
OH
R1
R1 = H, R2 = CH(O)
R1 = H, R2 = CMe(O)
R1 = R2 = CMe(O)
1b
OH
O
OH
+
Fe
Fe
O
OH
1c
2c
(i),(ii)
OH
OH
(R1 = R2 = CMe(O))
Fe
3
Scheme 1. Reagents and conditions: (i) LiCCCH2OLi (1–3 equiv.), THF, ꢁ78 °C; (ii) (CH3)2CHOH/H2O.

V.B. Golovko et al. / Journal of Organometallic Chemistry 693 (2008) 2683–2692
2685
l-g
2.2. Preparation of [Fc-1-R1-10-{Co2(CO)6- 2-CR(OH)C„CCH2OH}]
(4)
Interaction of 1a–1c with a slight excess of Co2(CO)8 in dichlo-
romethane at room temperature afforded [Fc-1-R1-10-{Co2(CO)6-
l
-
g
2-CR(OH)C„CCH2OH}] [R1 = R = H (4a); R1 = H, R = Me (4b);
R1 = CMe(O), R = Me (4c)] in high yields (Scheme 2). All the new
complexes have been characterised by IR, 1H and 13C NMR spec-
troscopy and LSI mass spectrometry (Table 2 and Section 4). In
addition, complexes 4b and 4c have been the subject of single crys-
tal X-ray diffraction studies.
Single crystals of 4b and 4c suitable for the X-ray determinations
were grown from a hexane:dichloromethane mixture at room tem-
perature. The structures of 4b and 4c are similar and will be dis-
cussed together. A perspective view of 4c is depicted in Fig. 3;
selected bond distances and angles for both 4b and 4c are listed in
Table 3. The molecular structures consist of
a HOCH2C„
CC(OH)(Me)–R chain [R = Fc (4b),
(g
5-C5H4)( 5-C5H4CMeO)Fe
g
(4c)] in which each alkynic group is perpendicularly bound by a
dicobalt hexacarbonyl unit. The Co2C2 cores adopt the expected tet-
rahedral arrangements with the Co–Co and C(alkyne)–C(alkyne)
bond distances falling within the normal ranges [13,14]; the coordi-
nated carbonyl ligands display the expected linear geometries. The
C–C„C bend-back angles [C(7)–C(8)–C(9) 136.3(3) (4b), 143.3(4)
(4c); C(10)–C(9)–C(8) 136.3(2) (4b), 142.0(4) (4c)°] within each
complex are similar in magnitude and comparable with those found
Fig. 2. Molecular structure of 2c0 with a partial atom labeling scheme; all hydrogen
atoms, apart from H2N and H8, have been omitted for clarity.
Table 1
Selected bond distances (Å) and angles (°) for 2c0
Range Fe(1)–C(1–4)
Fe(1)–C(5)
Range Fe(1)–
C(12–15)
2.039(3)–2.044(3)
2.059(3)
2.039(3)–2.051(4)
C(10)–C(11)
C(16)–C(17)
C(17)–N(1)
1.325(12)
1.466(5)
1.295(4)
in the related complexes [Co2(CO)6(
l-g
2-HOCR2CCCR2OH)] [R = H
136.64(av)°, Me 141.72(av)°] [15] and [Co2(CO)6(l-g
2-HOCHRCC-
CHROH)] [R = Me 137.49(av)°, Et 136.97(av)°, Ph 135.6(av)°]
[15a,16]. The relative disposition of the hydroxyl groups within
the HOCH2C„CC(OH)(Me)–R chains in 4b and 4c do, however, show
some differences. In 4b the two oxygen atoms are disposed in such a
way that the hydrogen atom on O(8) can undergo an intramolecular
interaction [O(8)ꢀ ꢀ ꢀO(7) 2.679 Å] with O(7). In 4c no comparable
hydrogen bond is evident with the corresponding oxygen atoms
positioned far apart [O(8)ꢀ ꢀ ꢀO(7) 6.161 Å]. Inspection of the packing
picture for 4b and 4c reveals the presence of a number of intermo-
lecular contacts with the closest interaction involving a hydroxyl
hydrogen atom in one molecule with either a neighbouring hydro-
xyl oxygen [O(7)ꢀ ꢀ ꢀO(8A) 2.651 Å (4b)] or with a neighbouring
ketonic oxygen atom [O(7)ꢀ ꢀ ꢀO(9A) 2.571 Å (4c)].
Fe(1)–C(16)
C(5)–C(6)
C(6)–C(8)
C(8)–C(9)
C(9)–C(10)
C(5)–C(6)–C(8)
C(6)–C(8)–C(9)
C(16)–C(17)–N(1)
2.046(3)
1.463(5)
1.355(5)
1.485(6)
1.458(9)
120.4(3)
127.1(4)
115.9(3)
N(1)–N(2)
N(2)–C(19)
C(22)–N(3)
C(24)–N(4)
Range N–O
C(17)–N(1)–N(2)
N(1)–N(2)–C(19)
1.388(4)
1.345(4)
1.459(5)
1.445(4)
1.218(5)–1.237(4)
114.9(3)
119.6(3)
ane:chloroform mixture. A view of 2c0 is depicted in Fig. 2; selected
bond lengths and angles are collected in Table 1.
The structure of 2c0 consists of a 1,10-disubstituted ferrocene
unit with one cyclopentadienyl ring containing a C(Me)@N–
The IR spectra of 4a–4c display the characteristic set of bands
for dicobalt hexacarbonyl-coordinated monoyne moieties
[4,5,13], while their LSI mass spectra display molecular ions (and
M++Na peaks) along with fragmentation peaks corresponding to
the loss of successive carbonyl groups. In their 1H NMR spectra res-
onances corresponding to the cyclopentadienyl protons are accom-
panied by signals due to the coordinated –C(OH)RC„CCH2OH
chains [R = H (4a), R = Me (4b, 4c)]. For example, the C„CCH2OH
protons are all observed around d 4.7 with those in 4b taking the
form of a doublet (3JH–H 5.7 Hz) while in 4c the methylene protons
are inequivalent resulting in a multiplet; the expected mutually
coupled hydroxyl protons are also evident. In the 13C NMR spec-
trum of 4a the inequivalent alkynic carbon atoms are shifted
downfield on coordination (c.f., 1a) as are the signals due to the
propargylic carbon atoms [d 63.8 (FcCHOH) and 63.7
(C„CCH2OH)]. Notably, the FcCHOH carbon signal in 4a is shifted
by only 2.5 ppm on coordination to the Co2(CO)6 moiety, compared
to the 13 ppm shift for the –C„CCH2OH carbon signal, indicating
that the ferrocene moiety activates the adjacent propargyl site
(FcCHOH) even in the free alkyne (1a) [8].
NH{2,4-(NO2)2C6H3} substituent and the other
a
C(Me)@
CHCH2CH2CH3 group. It is apparent that during the acid-cata-
lysed condensation reaction to form 2c0 the hydroxyl group in
2c has been eliminated by dehydration to yield an alkene
[C(6)–C(8) 1.355(5) Å], with the n-propyl and ferrocene substitu-
ents adopting a trans configuration [tors.: C(5)–C(6)–C(8)–C(9)
179.2°]. The spectroscopic properties of 2c0 are consistent with
the solid state structure being maintained in solution (see Exper-
imental Section). In the 1H NMR spectrum, the vinylic hydrogen
atom takes the form of a poorly resolved triplet of doublets at
d 5.62 as a result of coupling to the neighbouring methylene
group and the vinylic methyl group; the hydrazide NH proton
is seen as a singlet at d 11.26. The presence of a downfield signal
at d 154.7 in the 13C NMR spectrum confirms the formation of
the imine unit.
The isolation of 2a, 2c and 3 indicates that nucleophilic attack
by a butyl group (from any unreacted n-BuLi) at the correspond-
ing carbonyl-containing ferrocene represents a competing side
reaction in this chemistry. The low yield observed for 1b sug-
gests that a similar reaction pathway is likely, leading in this
case to products that are not amenable to chromatographic sep-
aration. Nevertheless, sufficient quantities of the desired alkynic
species 1a–1c were obtained in order to allow further studies
(vide infra).
2.3. Acid-catalysed reaction of 4 with sulfur-based nucleophiles
In order to explore the capability of 4 to undergo nucleophilic
substitution reactions, 4a was initially chosen as the substrate

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V.B. Golovko et al. / Journal of Organometallic Chemistry 693 (2008) 2683–2692
SPh
OH
H
Fe
Co2(CO)6
SPh
5
(ii)
SPh
(
4a
)
H
Fe
Co2(CO)6
6
(CH2)n
OH
OH
S
S
OH
(iii)
(i)
R
R
H
Fe
Fe
(
4a
)
Fe
R1
R1
OH
Co2(CO)6
Co2(CO)6
R1 = R = H
R1 = R = H
4a
R1 = H, R = Me
7a n = 2
n = 3
1a
R1 = H, R = Me
7b
4b
R1 = CMe(O), R = Me 4c
1b
R1 = CMe(O), R = Me 1c
OH
(iv) or (v)
Fe
(
4b
)
CMe(O)
Co2(CO)6
8
Scheme 2. Reagents and conditions: (i) Co2(CO)8, CH2Cl2, RT; (ii) HBF4 ꢀ OEt2 (cat.), C6H5SH, CH2Cl2, ꢁ78 °C; (iii) HBF4 ꢀ OEt2 (cat.), HS(CH2)nSH, CH2Cl2, ꢁ78 °C; (iv) HBF4 ꢀ OEt2
(cat.), HS(CH2)2O(CH2)2SH, CH2Cl2, ꢁ78 °C; (v) HBF4 ꢀ OEt2 (cat.), CH2Cl2, ꢁ78 °C.
Table 2
Selected characterisation data for the cobalt carbonyl-containing complexes 4–8
a
Complex
m
(CO) (cmꢁ1
)
1H NMRb
LSI mass spectrum
4a
2028(vs), 2056(vs),
2094(m)
d 5.59 (d, 1H, C5H4CHOH, 3JH–H 1.9), 4.73 (m, 2H, CH2) 4.33–4.32 (m, 1H, C5 H4), 4.27–4.26 (m,
1H, C5 H4), 4.26 (s, 5H, C5 H5), 4.25–4.19 (m, 2H, C5 H4), 2.82 (d, 1H, CHOH, 3JH–H 1.9), 2.46 (m,
1H, CH2OH).
M++H (557), M+ꢁOH (539),
M+ꢁnCO (n = 2–6)
4b
4c
2027(vs), 2056(vs),
2092(m)
d 4.68 (d, 2H, C„CCH2OH, 3JH–H 5.7), 4.31 (s, 1H, C5H4), 4.20 (s, 5H, C5H5), 4.16–4.11 (m, 3H,
C5H4), 3.00 (s, 1H, C5H4CMeOH), 2.87 (t, 1H, CH2OH, JH–H 5.7), 1.91 (s, 3H, CH3).
M++Na (593), M+ (570), M+ꢁOH
(553), M+ꢁnCO (n = 2–6)
M++Na (635), M+ꢁnCO (n = 2–5)
3
2028(vs), 2056(vs),
2093(vs)
d 4.94 (t, 1H, C5H4, 3JH–H 1.3), 4.76 (t, 1H, C5H4, 3JH–H 1.3), 4.74–4.71 (m, 2H, CH2OH, 3JH–H 6.3,
3JH–H 4.6), 4.62–4.61 (m, 1H, C5H4), 4.58 (m, 1H, C5H4), 4.33 (m, 1H, C5H4), 4.32–4.31 (m, 1H,
C5H4), 4.17–4.16 (m, 1H, C5H4), 4.15–4.14 (m, 1H, C5H4), 3.47 (s, 1H, C5H4COH) 3.16 (dd, 1H,
3
3
CCCH2OH, JH–H 6.3, JH–H 4.6), 2.41 (s, 3H, C5H4COCH3), 1.99 (s, 3H, C5H4C(OH)CH3).
5
6
2029(vs), 2053(vs),
2062(s), 2092(m),
2099(m)
d 7.57 (d, 2H, C6H5, 3JH–H 7.5), 7.43 (t, 2H, C6H5, 3JH–H 7.5), 7.31 (t, 1H, C6H5, 3JH–H 7.5), 5.50 (s,
1H, C5H4CHSPh), 4.39 (s, 1H, C5H4), 4.32 (s, 1H, C5H4), 4.27 (s, 1H, C5H4), 4.23 (s, 5H, C5H5),
4.21 (s, 1H, C5H4), 4.11 (d, 2H, CH2OH, JH–H 7), 1.52 (t, 1H, CH2OH, JH–H 7).
M++Na (671), M+ (648), M+ꢁnCO
(n = 2–5)
3
3
3
2028(vs), 2056(vs),
2094(m)
d 7.64–7.62 (m, 2H, C6H5), 7.40 (t, 2H, C6H5, JH–H 7.7), 7.29–7.19 (groups of m, 6H,
M++H (741), M+ꢁnCO (n = 3–6)
CH2SC6H5), 5.71 (s, 1H, C5H4CHSPh), 4.42 (m, 1H, C5H4), 4.32 (m, 1H, C5H4), 4.25 (m, 1H,
C5H4), 4.21 (s, 5H, C5H5), 4.19–4.18 (m, 1H, C5H4), 3.87 (d, 1H, CH2, 3JH–H 14), 3.76 (d, 1H, CH2,
3JH–H 14).
7a
7b
8
2027(vs), 2058(vs),
2095(m)
d 4.92 (s, 1H, C5H4CHSCH2), 4.24–4.13 (groups of m, 9H, C5H4 and C5H5), 4.06–4.04 (m, 2H,
C„CCH2S), 3.68–3.64 (m, 1H, SCH2), 3.38–3.34 (m, 1H, SCH2), 3.02–2.91 (m, 2H, SCH2).
M+ (614), M+ꢁnCO (n = 3–6)
M++H (629), M+ꢁnCO (n = 2–6)
M+ꢁnCO (n = 1–5)
2027(vs), 2056(vs),
2096(m)
d 5.06 (s, 1H, C5H4CHSCH2), 4.36–4.18 (groups of m, 11H, C5H4, C5H5 and C„CCH2S), 3.06 (m,
2H, (CH2)3), 2.90–2.88 (m, 2H, (CH2)3), 2.43 (m, 1H, (CH2)3), 2.28 (m, 1H, (CH2)3).
2027(vs), 2053(vs),
2091(s)
d 5.76 (br. s, 1H, C@CH2), 5.01 (br. s, 1H, C@CH2), 4.99 (s, 2H, C5H4), 4.42 (s, 2H, CH2), 4.30 (s,
2H, C5 H4), 4.16 (s, 5H, C5 H5), 1.93 (s, 1H, CH2OH).
a
Recorded in CH2Cl2 (apart from 6a in THF) in 0.5 mm NaCl solution cells.
b
1H NMR chemical shifts in ppm relative to SiMe4 (0.0 ppm), coupling constants in Hz in CDCl3 at 293 K.
and its reactivity towards a range of sulfur-based nucleophiles was
l
-
g
2-CH(SPh)C„CCH2OH}] (5) as the minor product and the bis-
capped species [Fc-1-H-10-{Co2(CO)6- 2-CH(SPh)C„CCH2SPh}]
examined. Thus, reaction of complex 4a with one equivalent of
PhSH in dichloromethane at ꢁ78 °C in the presence of a catalytic
quantity of HBF4 ꢀ OEt2 affords, on work-up, [Fc-1-H-10-{Co2(CO)6-
l-g
(6) as the major product (Scheme 2). Use of the dithols HS(CH2)nSH
(n = 2, 3) in place of thiophenol in the above reaction affords the

V.B. Golovko et al. / Journal of Organometallic Chemistry 693 (2008) 2683–2692
2687
the asymmetric unit which differ mainly in the conformation of the
S(CH2)3S bridging moiety. In molecule A the moiety is disposed on
one side of the coordinated alkynic C–C vector (cis-isomer) while in
molecule B the S(CH2)3S unit is located across the coordinated C„C
bond (trans-isomer). The following discussion will be concerned
with molecule A; any significant variations in B will be highlighted.
The structureconsists of a nine-membered –S–C–C–C–S-C–C„C–C–
dithiomacrocycle in which the alkynic moiety is
g
2-bridged
by a dicobalt hexacarbonyl unit. The Co2C2 core adopts the ex-
pected pseudo tetrahedral geometry with the bond parameters
within the core falling in the normal ranges [13,14]. The Co2C2
cores in each isomer are slightly skewed: C(10)–C(9)–Co(1)
129.73(17)° vs. C(10)–C(9)–Co(2) 136.10(17)° (trans-isomer) and
C(10)–C(9)–Co(1) 140.54(18)° vs. C(10)–C(9)–Co(2) 128.58(17)°
(cis-isomer). The alkyne bend-back angles are comparable
Fig. 3. Molecular structure of 4c with a partial atom labeling scheme; all hydrogen
atoms, apart from H7 and H8, have been omitted for clarity.
Table 3
Selected bond distances (Å) and angles (°) for 4b and 4c
4b
4c
Range Fe(1)–C(17, 19–21)
Fe(1)–C(18)
–
–
2.037(4)–2.067(5)
2.031(4)
Range Fe(1)–C(17–21)
Range Fe(1)–C(13–16)
Fe(1)–C(12)
2.037(3)–2.051(3)
2.036(3)–2.045(3)
2.041(3)
–
2.025(5)–2.052(4)
2.057(4)
1.510(6)
Fig. 4. Molecular structure of 7b (molecule A) with a partial atom labeling scheme;
all hydrogen atoms have been omitted for clarity.
C(12)–C(10)
1.507(4)
C(10)–O(8)
1.437(3)
1.402(6)
C(10)–C(11)
C(10)–C(9)
C(9)–C(8)
1.521(4)
1.507(4)
1.345(4)
1.491(8)
1.510(6)
1.347(6)
Table 4
Selected bond distances (Å) and angles (°) for 7b
C(8)–C(7)
C(7)–O(7)
C(22)–O(9)
Co(1)–Co(2)
Co–C(carbonyl)
C–O(carbonyl)
Co–C(alkyne)
1.491(4)
1.433(3)
–
2.4764(5)
1.796(4)–1.825(3)
1.133(3)–1.136(4)
1.947(3)–1.979(3)
1.478(6)
1.437(6)
1.236(7)
2.4776(8)
1.790(6)–1.832(5)
1.122(6)–1.142(6)
1.952(4)–1.976(4)
Molecule A
Molecule B
Range Fe(1)–C(12–15)
Fe(1)–C(11)
Range Fe(1)–C(16–20)
C(11)–C(10)
C(10)–C(9)
C(9)–C(8)
C(8)–C(7)
C(7)–S(1)
S(1)–C(21)
2.025(3)–2064(3)
2.070(2)
2.037(3)–2.050(3)
1.507(3)
1.509(3)
1.341(3)
1.494(3)
1.816(3)
1.787(3)
1.524(4)
2.035(3)–2.052(3)
2.067(2)
2.039(3)–2.047(3)
1.506(3)
1.508(3)
1.336(3)
1.497(3)
1.822(3)
1.819(3)
1.526(4)
O(9)–C(22)-(C23)
C(12)–C(10)–O(8)
C(12)–C(10)–C(11)
C(12)–C(10)–C(9)
C(10)–C(9)–C(8)
C(9)–C(8)–C(7)
–
122.1(5)
107.9(4)
111.8(4)
106.8(3)
142.0(4)
143.3(4)
112.3(4)
110.7(2)
112.2(2)
108.1(2)
136.3(2)
136.3(3)
107.2(2)
C(21)–C(22)
C(22)–C(23)
C(23)–S(2)
1.518(4)
1.809(3)
1.830(2)
1.517(4)
1.809(2)
1.830(2)
C(8)–C(7)–O(7)
S(2)–C(10)
Co(1)–Co(2)
Co–C(carbonyl)
C–O(carbonyl)
Co–C(alkyne)
2.4628(5)
2.4591(5)
1.795(3)–1.824(3)
1.132(3)–1.137(3)
1.956(2)–1.973(2)
1.793(4)–1.827(3)
1.132(4)–1.141(4)
1.967(3)–1.984(3)
macrocyclic
complexes
[Fc-1-H-10-{cyclo-Co2(CO)6- g2
l- -
CH(S(CH2)n–) C„CCH2S-}] [n = 2 (7a), n = 3 (7b)] in moderate yield.
Complexes 5–7 have all been characterised by IR, 1H and 13C NMR
spectroscopy and LSI mass spectrometry (Table 2 and Section 4). In
addition, complex 7b has been the subject of a single crystal X-ray
diffraction study.
Crystals of 7b suitable for the X-ray diffraction determination
were grown from hexane:dichloromethane solution. The molecu-
lar structure of 7b is shown in Fig. 4; selected bond lengths and an-
gles are collected in Table 4. There are two molecules (A and B) in
S(1)–C(7)–C(8)
C(7)–C(8)–C(9)
114.32(18)
148.7(2)
145.6(2)
114.21(17)
102.20(12)
114.6(2)
113.8(3)
117.0(2)
104.04(15)
107.75(16)
116.17(18)
146.8(2)
141.7(2)
114.06(17)
102.31(11)
115.69(18)
113.3(2)
114.86(19)
102.75(13)
108.64(17)
C(8)–C(9)–C(10)
C(9)–C(10)–S(2)
C(10)–S(2)–C(23)
S(2)–C(23)–C(22)
C(23)–C(22)–C(21)
C(22)–C(21)–S(1)
C(21)–S(1)–C(7)
C(11)–C(10)–S(2)

2688
V.B. Golovko et al. / Journal of Organometallic Chemistry 693 (2008) 2683–2692
[C(8)–C(9)–C(10) 145.6(2)° vs. C(7)–C(8)–C(9) 148.7(2)°] in size
with the average value greater than that found in the previously
reported eight-membered dithiomacrocyclic complex [{cyclo-Co2-
(CO)4(
No significant intermolecular interactions are apparent.
In the IR spectra of 5–7 the typical (CO) pattern of bands for
l-dppm)-l-g
2-CH2(S(CH2)2–)C„CCH2S-}] [138.7(av)°] [4a].
m
dicobalt hexacarbonyl-bridged alkynes is observed [4,5,13]. All
four complexes (5, 6, 7a, 7b) show molecular ion peaks (and/or
M++H/M++Na peaks) along with fragmentation corresponding to
the loss of carbonyl groups. In the 1H NMR spectrum of 5, the pres-
ence of a doublet (three-bond coupling to the hydroxyl proton) for
the CH2OH protons and a singlet for the FcCHSPh proton confirms
that the substitution has occurred selectively at the carbon atom
a
to the ferrocene unit. The 1H NMR spectrum of 6 indicates that the
C„CCH2SPh protons are inequivalent (analogously to 4a) and ap-
pear as doublets at d 3.87 and 3.76 with 3JH–H 14 Hz for each signal.
The presence of the bridging (CH2)n units in 7a (n = 2) and 7b
(n = 3) is revealed by a series of multiplets between d 3.68 and
2.28 in their 1H NMR spectra. In the 13C NMR spectra (recorded
at 293 K) for 6 and 7b only one type of carbonyl carbon resonance
is evident while in 7a two broad peaks are visible; the remaining
signals are consistent with the proposed formulations.
The isolation of the mixed SPh/OH species 5 from the acid-cat-
alysed reaction of 4a with thiophenol indicates that the presence of
the ferrocenyl unit
a- to a propargylic centre does indeed induce
some selectivity during the transformation. It would therefore
seem likely that appended ferrocenyl group affects the stability
of the intermediate propargylic cation in such a way as to drive
the selective nucleophilic attack [8]. A related stepwise formation
of macrocycles 7 would also seem probable.
Fig. 5. Molecular structure of 8 with a partial atom labeling scheme; all hydrogen
atoms, apart from H11A and H11B, have been omitted for clarity.
In an attempt to extend the ability of 4a to act as template for the
formation of ring systems, the reaction of 4b with the bis(2-mercap-
toethyl) ether, in the presence of catalytic amount of HBF4 ꢀ OEt2,
Table 5
Selected bond distances (Å) and angles (°) for 8
Range Fe(1)–C(13–16) 2.037(2)–2.0476(19) C(8)–C(7)
Fe(1)–C(12)
Range Fe(1)–C(17–21) 2.039(2)–2.045(2)
C(12)–C(10)
C(10)–C(11)
C(10)–C(9)
1.489(3)
1.415(3)
2.4635(4)
was investigated. On work-up complex [Fc-1-H-10-{Co2(CO)6-
l-
2.0605(19)
C(7)–O(7)
Co(1)–Co(2)
g
2-C(@CH2)C„CCH2OH}] (8) could be isolated as the sole product
1.477(3)
1.337(3)
1.466(3)
Co–C(carbonyl) 1.792(2)–1.827(2)
in modest yield (Scheme 2). Complex 8 could also be isolated in
comparable yield on treatment of 4b with the acid catalyst in the ab-
sence of the bis(2-mercaptoethyl) ether. Complex 8 has been char-
acterised by IR, 1H and 13C NMR spectroscopy and LSI mass
spectrometry (Table 2 and Section 4). In addition, complex 8 has
been the subject of a single crystal X-ray diffraction study.
C–O(carbonyl)
Co–C(alkyne)
1.129(3)–1.135(3)
1.9631(18)–
1.9939(18)
C(9)–C(8)
1.343(3)
C(12)–C(10) –C(9)
C(12)–C(10)–C(11)
C(11)–C(10)–C(9)
118.70(16)
120.74(18)
120.53(18)
C(10)–C(9)–C(8) 146.26(18)
C(9)–C(8)–C(7) 145.53(18)
C(8)–C(7)–O(7) 113.17(17)
Crystals of 8 suitable for the X-ray determination were grown
from hexane:dichloromethane solution. The molecular structure
is depicted in Fig. 5; selected bond lengths and angles are pre-
sented in Table 5. The structure consists of a FcC(@CH2)C„CCH2OH
chain in which the alkynic group is perpendicularly bound by a
dicobalt hexacarbonyl unit. The bond lengths and angles of the al-
most tetrahedral Co2C2 core are all within the expected range
[13,14]. The Co(1) atom is located slightly closer to the C(8) atom
than to C(9), probably due to the steric demands of the ferrocene
moiety [Co(1)–C(8) is 1.9631(18) Å vs. Co(1)–C(9) of
1.9939(18) Å]. The C(9)–C(10) and C(10)–C(12) bonds are short-
ened by ca. 0.03–0.04 Å compared to 4b, consistent with increased
communication between the ferrocene and dicobalt moieties via
the more delocalised bridging C(@CH2) moiety in 8. The alkyne
bend-back angles are similar [C(7)–C(8)–C(9) 145.53(18)° vs.
C(10)–C(9)–C(8) 146.23(18)°] in size with the average value signif-
icantly larger than that found in 4b. No significant intermolecular
interactions are apparent.
Previous studies of dicobalt hexacarbonyl-coordinated propar-
gyl alcohols with alkyl groups on the propargyl centre have shown
that acid-catalysed dehydration reactions are commonplace [1a].
Therefore it would seem likely that during the reaction of 4b, for-
mation of an intermediate carbocation by protonation of the OH
group
a to the ferrocenyl group occurs preferentially (cf. reaction
of 4a to give 5) before subsequent loss of H2O to give 8. Neverthe-
less, it is uncertain why no substitution chemistry occurs at the
unsubstituted propargylic centre.
3. Conclusions
A family of ferrocenyl-containing but-2-yne-1,4-diols (1a–1c)
has been successfully prepared and their alkynic moieties coordi-
nated to dicobalt hexacarbonyl units (4a–4c). The capacity of 4a
to undergo acid-catalysed substitution reactions with mono- and
di-thiols has been demonstrated leading to linear chain (5 and 6)
and macrocyclic complexes (7). In the case of the chain products,
initial substitution takes place at the ferrocenyl-substituted prop-
argylic carbon atom. An attempt to form a macrocycle using the
more sterically congested 4b resulted only in dehydration to give
The IR spectrum of 8 confirms the presence of a dicobalt hexa-
carbonyl moiety in the molecule with three characteristic m(CO)
bands [4,5,13]. The 1H NMR spectrum of 8 is consistent with the
solid state structure being maintained in solution with two broad
singlets due to the inequivalent C@CH2 protons visible at d 5.76
and 5.01. The unreacted propargyl group CH2OH protons gives rise
to a peak at d 4.42 while the CH2OH proton is seen at d 1.93.

V.B. Golovko et al. / Journal of Organometallic Chemistry 693 (2008) 2683–2692
2689
8; a pathway also, however, likely to involve preferential reactivity
at the ferrocenyl-substituted propargylic carbon atom. The appli-
cation of 7 and related macrocycles in the field of redox-active
receptor molecules will be examined elsewhere [17].
C
15H20OFe: 272): MNa+: 295; M+: 272; M+ꢁH2O: 255. Compound
3
1a: 1H NMR (500 MHz, CD3CN): d 5.21 (d, 1H, C5H4CHOH, JH–H
6.5), 4.37 (m, 1H, C5H4), 4.28 (m, 1H, C5H4), 4.27 (d, 2H, CCCH2,
3JH–H 1.6), 4.20 (s, 5H, C5H5), 4.17–4.15 (m, 2H, C5H4), 3.42 (d, 1H,
3
3
CHOH, JH–H 6.5), 3.18 (t, 1H, CH2OH, JH–H 1.6). HMQC: 5.21
(61.3), 4.37 (67.7), 4.28 (68.8), 4.27 (50.7), 4.20 (69.8), 4.17–4.15
(68.8, 69.0). 13C NMR (125 MHz, CD3CN): d 90.2, 85.8 (C, C„C),
83.9 (C, C5H4), 69.8 (CH, C5H5), 69.0, 68.83, 68.79, 67.71 (CH,
C5H4), 61.3 (CH, C5H4CHOH), 50.7 (CH2OH). MS (LSIMS): (M for
4. Experimental
4.1. General procedures and materials
C
14H14O2Fe: 270): MNa+: 293; M+: 270; MH+ꢁH2O: 255. Anal. Calc.
Unless otherwise stated all experiments were carried out under
an atmosphere of dry, oxygen-free argon, using standard Schlenk
line techniques and solvents freshly distilled from appropriate dry-
ing agent [18]. NMR spectra were recorded in CDCl3 at ambient
temperature using a Bruker DRX-500 or a AM-400 spectrometer
with TMS as an external standard for 1H and 13C spectra; coupling
constants are measured in Hertz (Hz). 1H–1H COSY, HMQC and
HMBC NMR experiments were employed to obtain 1H–1H and
1H–13C correlated spectra [19]. Infrared spectra were, unless other-
wise stated, recorded in dichloromethane solution in 0.5 mm NaCl
solution cells, using a Perkin Elmer 1710 Fourier Transform Spec-
trometer. LSI (Liquid Secondary Ion) mass spectra were recorded
on a Micromass Autospec high resolution double focusing mass
spectrometer at the EPSRC National Mass Spectrometry Service
Centre at the University of Wales, Swansea. Electrospray (ESI) mass
spectra were recorded on a Micromass Quattro LC instrument at
the University of Cambridge, Mass Spectrometry Services. Elemen-
tal analyses were performed either at the University of Cambridge
or at the Science Technical Support Unit, London Metropolitan Uni-
versity. Column chromatography was performed on Kieselgel 60
(70–230 mesh ASTM). Preparative TLC was carried out on 1 mm sil-
ica plates prepared at the University of Cambridge. All products are
listed in order of decreasing Rf. The reagents, propargyl alcohol, n-
butyl lithium (1.5M in hexane), ferrocenecarboxaldehyde, acetyl-
ferrocene, 1,10-diacetylferrocene, 2,4-dinitrophenylhydrazine,
dicobalt octacarbonyl, thiophenol, 1,2-ethanedithiol, 1,3-propane-
dithiol, bis(2-mercaptoethyl) ether and tetrafluoroboric acid
(48 wt. % in diethyl ether) were obtained from Aldrich Chemical
Co. and used without further purification.
for C14H14O2Fe: C, 62.25; H, 5.22; Found: C, 62.34; H, 5.25%.
4.3. Synthesis of 1b
To a solution of HC„CCH2OH (0.78 ml, 0.751 g, 13.4 mmol) in
tetrahydrofuran (100 ml) at ꢁ78 °C was added n-BuLi (18.0 ml,
27.0 mmol, 2 equiv.) dropwise. The viscous mixture was left to stir
for 2 h at ꢁ78 °C. A solution of acetylferrocene (2.05 g, 9.0 mmol,
0.67 equiv.) in tetrahydrofuran (50 ml) was added, the reaction
mixture left to stir for 0.5 h at ꢁ78 °C and then allowed to warm
slowly to room temperature and stirred for a further 5 h. Isopropa-
nol (20 ml) was introduced and the resulting mixture stirred for
0.5 h before being poured onto a water–ice mixture (200 ml). The
organic layer was collected and the aqueous layer was extracted
with chloroform (3 ꢂ 50 ml). The combined organic extracts were
dried over MgSO4, filtered and the solvent removed under reduced
pressure. The oily residue was dissolved in the minimum amount
of dichloromethane, adsorbed onto silica and applied to top of a
chromatography column. Elution with hexane:ethyl acetate (4:1)
afforded
[Fc-1-H-10-{CMe(OH)C„CCH2OH}]
(1b)
(0.957 g,
2.31 mmol, 10%) as a yellow solid. Compound 1b: 1H NMR
3
(400 MHz, CDCl3): d 4.49–4.38 (d, 2 H, C„CCH2OH, JH–H 6.2),
4.35 (m, 1H, C5H4), 4.31–4.30 (m, 1H, C5H4), 4.23 (s, 5H, C5H5),
4.20–4.19 (m, 1H, C5H4), 4.17–4.16 (m, 1H, C5H4), 2.51 (q, 1H,
4
4
C5H4CMeOH, JH–H 0.3), 1.70 (d, 3H, CH3, JH–H 0.3), 1.56 (t, 1H,
3
CH2OH, JH–H 6.2). MS (ESI): (M for C15H16O2Fe: 284): MNa+: 307;
M+: 284.
4.4. Syntheses of 1c, 2c and 3
4.2. Synthesis of 1a and 2a
To a solution of HC„CCH2OH (3.25 ml, 3.1 g, 55.56 mmol) in
tetrahydrofuran (300 ml) at ꢁ78 °C was added n-BuLi (85 ml,
127.5 mmol, 2.3 equiv.) dropwise. The viscous mixture was left
to stir for 2 h at ꢁ78 °C. A solution of 1,10-diacetylferrocene
(5.0 g, 18.5 mmol, 0.33 equiv.) in tetrahydrofuran (100 ml) was
slowly added, the resulting mixture left to stir at ꢁ78 °C for 0.5 h
and then allowed to warm slowly to room temperature and stirred
for a further 5 h. Isopropanol (20 ml) was added and the mixture
stirred for 0.5 h before being poured onto a water–ice mixture
(200 ml). The organic layer was collected and the aqueous layer ex-
tracted with chloroform (3 ꢂ 50 ml). The combined organic ex-
tracts were dried over MgSO4, filtered and all volatiles removed
under reduced pressure. The oily residue was re-dissolved in the
minimum amount of dichloromethane, adsorbed onto silica and
applied to the top a chromatography column. Elution with hex-
ane:ethyl acetate (2:1) afforded trace amounts of a mixture com-
posed of ferrocene and [Fc-1,10-{CMe(OH)(CH2)3CH3}2] (3).
Further elution with hexane:ethyl acetate (2:1) afforded minor
quantities of 3 (0.045 g, 0.12 mmol, <1%) as a yellow oil. Subse-
quent elution with hexane:ethyl acetate (1:1) afforded [Fc-1-
{CMe(O)–10-{CMe(OH)(CH2)3CH3}] (2c) (3.346 g, 10.23 mmol,
55%) as a yellow oil. Elution with hexane:ethyl acetate (1:1) gave
unreacted 1,10-diacetylferrocene (0.575 g). Finally, elution with
ethyl acetate afforded [Fc-1-{CMe(O)}-10-{CMe(OH)C„CCH2OH}]
(1 c) (0.440 g, 1.22 mmol, 7%) as a yellow oily solid. Compound
3: 1H NMR (400 MHz, CDCl3): d 4.33 (m, 1H, C5H4), 4.19 (m, 1H,
To a solution of HC„CCH2OH (1.36 ml, 1.31 g, 23.36 mmol) in
tetrahydrofuran (200 ml) at ꢁ78 °C was added n-BuLi (31.0 ml,
46.72 mmol, 2 equiv.) dropwise. The viscous mixture was left to
stir for a further 2 h at ꢁ78 °C. A solution of ferrocenecarboxalde-
hyde (5.00 g, 23.36 mmol, 1 equiv.) in tetrahydrofuran (50 ml)
was slowly added and the reaction mixture left to stir for 0.5 h at
ꢁ78 °C. On warming to room temperature, the mixture was stirred
for a further 0.5 h. Isopropanol (20 ml) was added and the resulting
mixture stirred for 0.5 h before being poured onto a water–ice mix-
ture (200 ml). The organic layer was collected and the aqueous
layer extracted with chloroform (3 ꢂ 50 ml). The combined organic
fractions were dried over MgSO4, filtered and the solvent removed
under reduced pressure. The oily residue was dissolved in the min-
imum amount of dichloromethane, adsorbed on silica and applied
to the top of a chromatography column. Elution with hexane:ethyl
acetate (4:1) afforded [Fc-1-H-10-{CH(OH)(CH2)3CH3}] (2a)
(0.629 g, 2.31 mmol, 10%). Further elution with hexane:ethyl ace-
tate (1:1) yielded [Fc-1-H-10-{CH(OH)C„CCH2OH}] (1a) (4.128 g,
15.29 mmol, 66%) as a yellow solid. Compound 2a: 1H NMR
(400 MHz, CDCl3): d 4.30 (m, 1H, C5H4CHOH), 4.23 (m, 1H, C5H4),
4.17 (s, 5H, C5H5), 4.16–4.14 (m, 3H, C5H4), 1.97 (d, 1H, CHOH,
3JH–H 3.5), 1.66–1.61 (m, 2H, CH(OH)CH2), 1.45–1.25 (m, 4H,
3
–CH2CH2CH3), 0.90 (t, 3H, CH3, JH–H 7.3). MS (LSIMS): (M for
C
15H20OFe: 272): M+: 272; M+ꢁH2O: 255. MS (ESI): (M for

2690
V.B. Golovko et al. / Journal of Organometallic Chemistry 693 (2008) 2683–2692
C5H4), 4.15–4.11 (groups of m, 5H, C5H4), 3.98 (m, 1H, C5H4), 3.87
(s, 1H, OH), 3.46 (s, 1H, OH), 1.72–1.54 (m, 4H, C5H4C(OH)CH2),
1.54 (s, 3H, C5H4C(OH)CH3), 1.44 (s, 3H, C5H4C(OH)CH3), 1.26–
1.24 (m, 4H, CH2CH2CH3), 1.18–1.16 (m, 4H, CH2CH2CH3), 0.88 (t,
(69.4), 2.25 (14.4), 1.97 (30.4), 1.85 (15.2), 1.36 (22.7), 0.88
(13.8). HMBC: d 9.15 (144.3, 137.5, 129.6, 128.9, 123.6), 8.31
(144.3, 137.5, 123.6), 7.98 (137.5, 128.9, 116.5), 5.62 (91.1, 30.4,
22.7, 15.2), 4.65 (82.6, 71.6, 68.1), 4.39 (82.6, 71.6, 68.1), 4.35
(91.1, 69.4, 66.3), 4.19 (91.1, 69.4, 66.3), 2.25 (154.7, 82.6, 14.4),
1.97 (129.8, 125.2, 22.7, 13.8), 1.85 (129.8, 125.2, 91.1, 15.2),
1.36 (125.2, 30.4, 13.8), 0.88 (30.4, 22.7). 13C NMR (125 MHz,
CDCl3): d 154.7 (C, C@N), 144.3 (C, C6H3), 137.5 (C, C6H3), 129.8
(C, C@CH), 129.6 (CH, C6H3), 128.9 (C, C6H3), 125.2 (CH, C@CH),
123.6 (CH, C6H3), 116.5 (CH, C6H3), 91.1 (C, C5H4CMe@CH), 82.6
(C, C5H4CMe@N), 71.6, 69.4, 68.1, 66.3 (CH, C5H4), 30.4 (CH2,
CH3C@CHCH2CH2CH3), 22.7 (CH2, CH3C@CHCH2CH2CH3), 15.2
(CH3, C5H4C(CH3)@C), 14.4 (CH3, C5H4C(CH3)@N), 13.8 (CH3,
CH3C@CHCH2CH2 CH3). MS (LSIMS): (M for C24H26O4FeN4: 490):
MNa+: 514; MH+: 491. Anal. Calc. for C24H26O4FeN4: C, 58.79; H,
5.31; N, 11.43; Found: C, 58.97; H, 5.23; N 11.19%.
3H, CH2CH2CH3, JH–H 7.0), 0.80 (t, 3H, CH2CH2CH3, JH–H 7). 13C
NMR (125 MHz, CDCl3): d 100.0 (C, C5H4), 99.0 (C, C5H4), 71.3 (C,
C5H4COH), 71.0 (C, C5H4COH), 67.4, 67.3, 67.19, 67.18, 67.1, 66.7,
66.3, 66.1 (CH, C5H4), 45.5, 43.8 (CH2,CMe(OH)CH2CH2CH2CH3),
29.1, 28.4 (CH3, C(OH)CH3), 26.7, 26.4 (CH2, CMe(OH)CH2
CH2CH2CH3), 23.2, 23.0 (CH2,CMe(OH)CH2CH2CH2CH3), 14.1, 14.0
(CH3,CH2CH2CH2CH3). MS (ESI): (M for C22H34O2Fe: 386): MNa+:
409; M+: 386; MH+ꢁnH2O (n = 1,2): 369, 351. Compound 2c: 1H
NMR (500 MHz, CDCl3): d 4.83–4.82 (m, 1H, C5H4), 4.75–4.74 (m,
3
3
3
1H, C5H4), 4.53–4.52 (t, 2H, C5H4, JH–H 2.0), 4.21–4.20 (m, 1H,
C5H4), 4.20–4.19 (m, 1H, C5H4), 4.13–4.12 (m, 1H, C5H4), 4.04–
4.03 (m, 1H, C5H4), 2.37 (s, 3H, C5H4COCH3), 2.19 (s, 1H, OH),
1.58–1.50 (m, 2H, C(OH)CH2), 1.48 (s, 3H, C5H4C(OH)CH3), 1.23–
1.14 (groups of m, 4H, CH2CH2CH3), 0.83–0.80 (t, 3H, CH2CH2CH3,
3JH–H 7.0). HMQC (125 MHz, CDCl3): 4.83–4.82 (coupled to C at
70.3), 4.75–4.74 (coupled to C at 69.8), 4.53–4.52 (coupled to C
at 72.6, 72.5), 4.21–4.20 (m, 1H, C5H4, coupled to C at 69.3),
4.20–4.19 (coupled to C at 67.8), 4.13–4.12 (coupled to C at
69.0), 4.04–4.03 (coupled to C at 68.2), 2.37 (coupled to C
at 27.5), 1.58–1.50 (coupled to C at 44.0), 1.48 (coupled to C at
28.2), 1.23–1.14 (coupled to C at 26.5, 23.0), 0.83–0.80 (coupled
to C at 14.0). 13C NMR (125 MHz, CDCl3): d 203.0 (C, C5H4COCH3),
101.6 (C, C5H4), 79.3 (C, C5H4), 72.6, 72.5 (CH, C5H4), 70.8 (C,
C5H4COH), 70.3, 69.8, 69.3, 69.0, 68.2, 67.8 (CH, C5H4), 44.0 (CH2,
CMe(OH) CH2CH2CH2CH3), 28.2 (CH3, C(OH)CH3), 27.5 (CH3,
C5H4COCH3), 26.5 (CH2, CMe(OH)CH2CH2CH2CH3), 23.0 (CH2,
CMe(OH)CH2CH2CH2CH3), 14.0 (CH3, CMe(OH)CH2CH2CH2CH3).
MS (ESI): (M for C18H24O2Fe: 328): MNa+: 351; MH+ꢁnH2O (n = 1,
2): 311, 293. Compound 1c: 1H NMR (400 MHz, CDCl3): d 4.84 (s,
1H, C5H4), 4.78 (s, 1H, C5H4), 4.56 (s, 2H, CH2OH), 4.35 (s, 2H,
C5H4), 4.26 (s, 2H, C5H4), 4.18 (s, 1H, C5H4), 4.15 (s, 1H, C5H4),
2.36 (s, 3H, C5H4COCH3), 1.61 (s, 3H, C5H4C(OH)(CCCH2OH) CH3).
13C NMR (125 MHz, CDCl3): d 204.4 (C, COCH3), 98.1, 88.4 (C,
C„C), 82.1 (C, C5H4COMe), 79.33 (C, C5H4COH), 73.6, 73.4, 71.5,
70.5, 69.6, 69.4, 68.5, 67.5 (CH, C5H4), 66.4 (C, C5H4COH), 50.7
(CH2, C„CCH2OH), 32.2 (CH3, C5H4COCH3), 27.6 (CH3, C(OH)CH3).
MS (ESI): (M for C17H18O3Fe: 326): MNa+: 349; MH+: 327;
MH+ꢁnH2O (n = 1, 2): 309, 291.
4.6. Synthesis of 4
(a) 4a: To a solution of 1a (3.923 g, 14.5 mmol) in dichloro-
methane (500 ml) at room temperature was added Co2(CO)8
(5.0 g, 14.6 mmol, 1 equiv.) in small portions. Evolution of CO
gas was accompanied by a rapid change in the colour of the solu-
tion from light yellow to dark red. The solution was allowed to
stir at room temperature for 6 h. All volatiles were removed un-
der reduced pressure and the residue re-dissolved in the mini-
mum amount of dichloromethane, adsorbed onto silica and
added to the top of a chromatography column. Elution with hex-
ane:ethyl acetate (5:1) afforded dark red [Fc-1-H-10-{Co2(CO)6-
2-CH(OH)C„CCH2OH}] (4a) (6.750 g, 12.1 mmol, 84%) as the
l-
g
sole major product. Compound 4a: MS (ESI): (M for C20H14O8Fe-
Co2: 556): MNa+: 579; M+: 556; M+ꢁOH: 539; M+ꢁnCO (n = 2–
5): 500–416. Compound 4a: 13C NMR (125 MHz, CDCl3): d 199.5
(C, CO), 99.2, 94.6 (C, C„C), 93.4 (C, C5H4), 71.3 (CH, C5H4),
68.6 (CH, C5H5), 68.3 (CH, C5H4), 67.3 (CH, C5H4), 63.8 (CH,
C5H4CHOH), 63.7 (CH2OH). Anal. Calc. for C20H14O8FeCo2: C,
43.19; H, 2.52; Found: C, 43.01; H, 2.71%.
(b) 4b: To a solution of 1b (0.957 g, 3.37 mmol) in dichloro-
methane (200 ml) at room temperature was added Co2(CO)8
(1.268 g, 3.70 mmol, 1 equiv.) in small portions. Evolution of CO
gas was accompanied by a rapid change in the colour of the solu-
tion from light yellow to dark red. The resulting dark red solution
was stirred at room temperature for 6 h and the solvent then re-
moved under reduced pressure. The residue was re-dissolved in
the minimum amount of dichloromethane, adsorbed onto silica
and applied to the top of a chromatography column. Elution with
hexane:ethyl acetate (5:1) afforded dark red [Fc-1-H-10-
4.5. Synthesis of 2c0
To a solution of 2c (1.0 g, 3.05 mmol) in absolute ethanol
(300 ml) (0.670 g, 3.4 mmol) was added 2,4-(NO2)2C6H3NHNH2 fol-
lowed by five drops of glacial acetic acid. The mixture was refluxed
overnight and left to stir for 2 days at room temperature. The dark
red crystalline precipitate formed during this period was filtered
and washed with absolute ethanol (2 ꢂ 50 ml) to afford deep red
{Co2(CO)6-l-g
2-CMe(OH)C„CCH2OH}] (4b) (1.644 g, 2.88 mmol,
86%). Compound 4b: Anal. Calc. for C21H16O8FeCo2: C, 44.23; H,
2.81; Found: C, 44.51; H, 2.78%.
(c) 4c: To a solution of 1c (0.440 g, 1.35 mmol) in dichloro-
methane (200 ml) at room temperature was added Co2(CO)8
(0.870 g, 2.54 mmol) in small portions. The resulting dark red
was stirred at room temperature for 6 h and the solvent then re-
moved under reduced pressure. The residue was re-dissolved in
the minimum amount of dichloromethane, adsorbed onto silica
and added to the top of a chromatography column. Elution with
hexane:ethyl acetate (2:1) afforded red-orange [Fc-1-{CMe(O)}-
crystalline
[Fc-1-(CMe@CHCH2CH2CH3)–10-(CMe@NNH-2,4-
(NO2)2C6H3)] (2c0) (1.441 g, 2.94 mmol, 97%). Compound 2c0: 1H
NMR (500 MHz, CDCl3): d 11.26 (s, 1H, NH), 9.15 (d, 1H, C6H3,
3JH–H 2.6), 8.31 (dd, 1H, C6H3, JH–H 9.6, JH–H 2.5), 7.98 (d, 1H,
3
3
3
3
3
C6H3, JH–H 9.6), 5.62 (td, 1H, C@CH–CH2CH2CH3, JH–H 7.3, JH–H
3
3
1.3), 4.65 (t, 2H, C5H4, JH–H 1.9), 4.39 (t, 2H, C5H4, JH–H 1.9), 4.35
(t, 2H, C5H4, JH–H 1.9), 4.19 (t, 2H, C5H4, JH–H 1.9), 2.25 (s, 3H,
C5H4C(@N–)CH3), 1.97 (q, 2H, C@CH–CH2CH2CH3, JH–H 7.3), 1.85
(d, 3H, C5H4C(CH3)@CHCH2CH2CH3, JH–H 1.3), 1.36 (sextet, 2H,
3
3
3
10-{Co2(CO)6-
l
-g
2-CMe(OH)C„CCH2OH}]
(4c)
(0.426 g,
3
0.64 mmol, 47%). Compound 4c: 13C NMR (125 MHz, CDCl3): d
203.9 (C, FcCOCH3), 199.2 (C, CO), 105.7, 101.3 (C, C„C), 94.5
(C, C5H4COMe), 79.4 (C, C5H4COH), 73.2 (C, C5H4COH), 73.0,
72.9, 71.3, 70.0, 69.8, 69.5, 68.0, 67.7 (CH, C5H4), 63.8 (CH2,
C„CCH2OH), 31.3 (CH3, C5H4COCH3), 27.6 (CH3, C(OH)CH3). Anal.
Calc. for C23H18O9FeCo2: C, 45.12; H, 2.94; Found: C, 44.98; H,
3.05%.
3
C@CH–CH2CH2CH3, JH–H 7.3), 0.88 (t, 3H, C@CH–CH2CH2CH3,
3JH–H 7.3). COSY: d 9.15 (weakly to 8.31), 8.31 (9.15, 7.98), 7.98
(8.31), 5.62 (1.97; weakly to 1.85), 4.65 (4.39), 4.39 (4.65), 4.35
(4.19), 4.19 (4.35), 1.97 (5.62, 1.36), 1.85 (weakly to 5.62), 1.36
(1.97, 0.88), 0.88 (1.36). HMQC: d 9.15 (123.6), 8.31 (129.6), 7.98
(116.5), 5.62 (125.2), 4.65 (68.1), 4.39 (71.6), 4.35 (66.3), 4.19

V.B. Golovko et al. / Journal of Organometallic Chemistry 693 (2008) 2683–2692
2691
4.7. Reaction of 4a with C6H5SH
(b) n = 3: To a solution of 4a (0.694 g, 1.25 mmol) and
HS(CH2)3SH (0.125 ml, 1.25 mmol, 1 equiv.) in dichloromethane
(200 ml) at ꢁ78 °C under argon was added five drops of 48%
HBF4 ꢀ OEt2. After warming to 0 °C an excess of NaHCO3 was added.
The resulting mixture was filtered through a plug of MgSO4 and the
solvent removed on a rotary evaporator. The residue was re-dis-
solved in the minimum amount of dichloromethane and the solu-
tion applied to the base of TLC plates. Elution with hexane:ethyl
To a solution of 4a (0.564 g, 1.01 mmol) and PhSH (0.12 ml,
1.173 mmol, 1.1 equiv.) in dichloromethane (200 ml) at ꢁ78 °C
was added five drops of 48% HBF4 ꢀ OEt2. After warming to 0 °C
an excess of NaHCO3 was added. The resulting mixture was
filtered through a plug of MgSO4 and the solvent removed on a
rotary evaporator. The residue was re-dissolved in the minimum
amount of dichloromethane and the solution applied to the base
of TLC plates. Elution with hexane:ethyl acetate (3:1) afforded the
acetate (6:1) afforded deep red [Fc-1-H-10-{cyclo-Co2(CO)6- g2
l- -
CH(S(CH2)3–)C„CCH2S-}] (7b) (0.345 g, 0.55 mmol, 44%). Com-
pound 7b: 13C NMR (125 MHz, CDCl3): d 206.9 (C, CO), 104.61,
97.3 (C, C„C), 90.6 (C, C5H4), 69.5 (CH, C5H4), 69.3 (CH, C5H5),
68.1, 67.5, 67.1 (CH, C5H4), 47.1 (CH, FcCHSCH2), 39.1
deep red oily [Fc-1-H-10-{Co2(CO)6-
(6) (0.359 g, 0.485 mmol, 48%) and some deep red oily [Fc-1-H-
10-{Co2(CO)6- 2-CH(SPh)C„CCH2OH}] (5) (0.097 g, 0.149 mmol,
l-g
2-CH(SPh)C„CCH2SPh}]
l-g
15%). Compound 6: 13C NMR (125 MHz, CDCl3): d 199.0 (C, CO),
136.7 (C, C6H5), 136.4 (C, C6H5), 129.7 (CH, C6H5), 129.4 (CH,
C6H5), 128.8 (CH, C6H5), 128.4 (CH, C6H5), 126.7 (CH, C6H5),
125.9 (CH, C6H5), 104.8, 94.3 (C, C„C), 90.9 (C, C5H4), 69.4
(C5H5), 69.0, 68.2, 67.2, 67.1 (C5H4), 51.7 (C5H4CHSPh), 38.4
(C„CCH2SPh).
(CH2,C„CCH2S),
FcCHSCH2CH2CH2S), 30.3 (CH2, FcCHSCH2CH2CH2S). Anal. Calc. for
23H18O6Co2 FeS2: C, 43.96; H, 2.87; Found: C, 44.15; H, 2.80%.
32.4
(CH2,
FcCHSCH2),
31.5
(CH2,
C
4.9. Reaction of 4b with or without HS(CH2)2O(CH2)2SH
(a) To a solution of 4b (0.800 g, 1.40 mmol) and HS(CH2)2-
O(CH2)2SH (0.20 ml, 1.7 mmol) in dichloromethane (200 ml) at
ꢁ78 °C was added five drops of 48% HBF4 ꢀ OEt2. After warming
to room temperature an excess of NaHCO3 was added. The result-
ing mixture was filtered through a plug of MgSO4 and the solvent
removed on a rotary evaporator. The residue was re-dissolved in
the minimum amount of dichloromethane and the solution applied
to the base of TLC plates. Elution with hexane:ethyl acetate (6:1)
4.8. Reaction of 4a with HS(CH2)nSH
(a) n = 2: To
a solution of 4a (0.655 g, 1.2 mmol) and
HS(CH2)2SH (0.10 ml, 1.2 mmol, 1 equiv.) in dichloromethane
(200 ml) at ꢁ78 °C was added five drops of 48% HBF4 ꢀ OEt2. On
warming to 0 °C an excess of NaHCO3 was added. The resulting
mixture was filtered through a plug of MgSO4 and the solvent re-
moved on a rotary evaporator. The residue was re-dissolved in
the minimum amount of dichloromethane and the solution applied
to the base of TLC plates. Elution with hexane:ethyl acetate (6:1)
afforded [Fc-1-H-10-{Co2(CO)6- 2–C(@CH2)C„CCH2OH}] (8)
l-g
(0.178 g, 0.32 mmol, 15%) as a deep red solid. Compound 8: Anal.
Calc. for C23H16O8Co2 Fe: C, 46.49; H, 2.70; Found: C, 46.71; H,
2.89%.
afforded a deep red oily solid [Fc-1-H-10-{cyclo-Co2(CO)6- g2
l- -
CH(S(CH2)2–)C„CCH2S–}] (7a) (0.407 g, 0.66 mmol, 55%) as the
sole product. Compound 7a: 13C NMR (125 MHz, CDCl3): d 199.4,
199.1 (C, CO), 106.5, 98.0 (C, C„C), 90.9 (C, C5H4), 69.3 (CH,
C5H5), 68.8, 68.5, 67.0, 66.6 (CH, C5H4), 52.4 (C5H4CHSCH2), 38.3
(C„CCH2), 37.0 (FcCHSCH2), 36.8 (FcCHSCH2CH2).
(b) To a solution of the complex 4b (1.07 g, 1.88 mmol) in
dichloromethane (200 ml) at ꢁ78 °C was added five drops of 48%
HBF4 ꢀ OEt2. After warming to 0 °C and stirring overnight, an excess
of NaHCO3 was added to the mixture. The resulting mixture was
filtered through a plug of MgSO4 and the solvent removed on a
Table 6
Crystallographic and data processing parameters for 2c0, 4b, 4c, 7b and 8
Complex
2c0
4b
4c
7b
8
Formula
M
C
24H26FeN4O4.CHCl3
C21H16Co2FeO8
570.05
C23H18Co2FeO9
612.08
C23H18Co2FeO6S2
628.20
C21H14Co2FeO7
552.03
609.71
Crystal size (mm3)
Temperature (K)
Crystal system
Space group
a (Å)
0.23 ꢂ 0.21 ꢂ 0.07
0.23 ꢂ 0.23 ꢂ 0.12
0.25 ꢂ 0.14 ꢂ 0.07
0.16 ꢂ 0.16 ꢂ 0.14
0.32 ꢂ 0.32 ꢂ 0.23
180(2)
180(2)
180(2)
180(2)
180(2)
Triclinic
Orthorhombic
P2(1)2(1)2(1)
7.8929(2)
10.9312(2)
25.4756(6)
90
Triclinic
Monoclinic
P2(1)/n
10.85610(10)
12.9819(2)
34.3721(5)
90
91.1600(10)
90
4843.16(11)
8
Monoclinic
P2(1)/c
13.5757(5)
7.7001(2)
20.7497(8)
90
108.6810(10)
90
2054.78(12)
4
ꢀ
ꢀ
P1
P1
10.4515(2)
11.7754(2)
13.0045(4)
109.9290(10)
92.5470(10)
113.6780(10)
1347.06(5)
2
7.5737(2)
11.6787(4)
14.2589(5)
109.987(2)
92.598(2)
91.024(2)
1183.28(7)
2
b (Å)
c (Å)
a
(°)
b (°)
90
90
c
(°)
U (Å3)
2198.01(9)
4
1.723
1144
2.188
Z
Dcalc (Mg mꢁ3
F(000)
)
1.503
628
0.896
1.718
616
2.041
1.723
2528
2.155
1.784
1104
2.334
l
(Mo K
a
) (mmꢁ1
)
Reflections collected
Independent reflections
Rint
16893
6140
0.456
17667
5003
0.0581
15141
5406
0.0449
54650
11048
0.0443
11594
4609
0.0381
Restraints/parameters
7/341
0/296
0/ 318
0/613
1/ 283
Final R indices (I > 2
r
(I))
R1 = 0.609,
wR2 = 0.1592
R1 = 0.0878,
wR2 = 0.1776
1.039
R1 = 0.0326,
wR2 = 0.0611
R1 = 0.0482,
wR2 = 0.0656
1.029
R1 = 0.0470,
wR2 = 0.1403
R1 = 0.0782,
wR2 = 0.1800
1.120
R1 = 0.0342,
wR2 = 0.0784
R1 = 0.0500,
wR2 = 0.0846
1.071
R1 = 0.0276,
wR2 = 0.0688
R1 = 0.0327,
wR2 = 0.0719
1.033
All data
Goodness of fit on
F2 (all data)
P
P
P
P
Data in common: graphite-monochromated Mo
Ka
radiation, k = 0.71073 Å; R1
=
||Fo| ꢁ |Fc||/ |Fo|, wR2 = [ (wF2o ꢁ F2c)2/ (wFo2)2]1/2
, w r
ꢁ1 = [ 2(Fo)2+(aP)2], P = [max
P
(Fo2,0) + 2(Fc2)]/3, where a is a constant adjusted by the program; goodness of fit = [ (Fo2 ꢁ F2c)2/(n ꢁ p)]1/2 where n is the number of reflections and p the number of parameters.

2692
V.B. Golovko et al. / Journal of Organometallic Chemistry 693 (2008) 2683–2692
(b) V.B. Golovko, M.J. Mays, G.A. Solan, J. Organomet. Chem. 692 (2007) 4985;
(c) D. Diaz, T. Martin, V.S. Martin, Org. Lett. 3 (2001) 3289.
[4] (a) A. Gelling, G.F. Mohmand, J.C. Jeffery, M.J. Went, J. Chem. Soc., Dalton Trans.
(1993) 1857;
rotary evaporator. The residue was dissolved in the minimum
amount of dichloromethane and the solution applied to the base
of TLC plates. Elution with hexane:ethyl acetate (6:1) afforded
[Fc-1-H-10-{Co2(CO)6- 2-C(@CH2)C„CCH2OH}] (8) (0.195 g,
l-g
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Single crystal X-ray diffraction data for 2c0, 4b, 4c, 7b and 8
were collected using a Nonius-Kappa CCD diffractometer, equipped
with an Oxford Cryosystems cryostream and employing Mo K
a
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atoms were included in calculated positions (C–H = 0.96 Å) riding
on the bonded atom with isotropic displacement parameters set
to 1.5Ueq(C) for methyl H atoms and 1.2Ueq(C) for all other H
atoms. Details of the data collection, refinement and crystal data
are listed in Table 6.
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Acknowledgements
We thank the Cambridge Overseas Trust for financial support to
V.B.G. The help of the EPSRC mass spectrometry service, Swansea is
gratefully acknowledged. Dr. John E. Davies is thanked for data col-
lection for the crystal structure determinations.
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Appendix A. Supplementary material
(b) M. Duran, S. Konstantinovic, V. Pavlovic, J. Predojevic, Z. Ratkovic, A.
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Acta 333 (2002) 15;
CCDC 672415, 672416, 672417, 672418 and 672419 contain the
supplementary crystallographic data for for compounds 2c0, 4b, 4c,
7b and 8. These data can be obtained free of charge from The Cam-
bridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif. Supplementary data associated with this article
can be found, in the online version, at doi:10.1016/
j.jorganchem.2008.05.011.
(b) H. Schottenberger, J. Lukassser, E. Reichel, A.G. Muller, G. Steiner, H.
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(e) M. Zirngast, C. Marschner, J. Baumgartner, Organometallics 25 (2006)
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