Synthesis of a vinylphosphine substituted cobalt lactonyl complex and insertion of CO into the lactonyl ring: Crystal structures of [Co{PPh2CPh=CPhCOC(O)CPhCPh}(CO)2] and [Co{PPh2CPh=CPhCC(O)OC(O)CPhCPh}(CO)2]

Article abstract of DOI:10.1021/om960150b

Two new cobalt complexes, [Co{PPh₂C-Ph=CPhCOCC(O)CPhCPh}(CO)₂] (4) and [Co{PPh₂-CPh=CPhCC(O)OC(O)CPhCPh}(CO)₂] (5), have been synthesized and spectroscopically and structurally characterized. Complex 4 is the major product of the condensation reaction of [Co₂(μ-PPh₂)₂(CO)₆] with diphenylacetylene under carbon monoxide pressure, while 5 is obtained from the reaction of 4 with sodium naphthalenide followed by [(η⁵-C₅H₅)Fe(CO)₂Cl]. The X-ray structures of 4 and 5 reveal the cobalt atoms to be respectively chelated by lactonyl and cyclic anhydride substituted vinylphosphines, so that 5 is formally derived from 4 by insertion of CO into the lactonyl ring.

Full text of DOI:10.1021/om960150b

Organometallics 1996, 15, 4085-4088
4085
Syn th esis of a Vin ylp h osp h in e Su bstitu ted Coba lt
La cton yl Com p lex a n d In ser tion of CO in to th e La cton yl
Rin g: Cr ysta l Str u ctu r es of
[Co{P P h 2CP h dCP h COC(O)CP h CP h }(CO)2] a n d
[Co{P P h 2CP h dCP h CC(O)OC(O)CP h CP h }(CO)2]
Andrew J . Edwards, Martin J . Mays,* Paul R. Raithby, and Gregory A. Solan
University Chemical Laboratory, Lensfield Road, Cambridge CB2 1EW, U.K.
Received February 29, 1996X
Summary: Two new cobalt complexes, [Co{PPh2C-
PhdCPhCOC(O)CPhCPh}(CO)2] (4) and [Co{PPh2-
CPhdCPhCC(O)OC(O)CPhCPh}(CO)2] (5), have been
synthesized and spectroscopically and structurally char-
acterized. Complex 4 is the major product of the
condensation reaction of [Co2(µ-PPh2)2(CO)6] with diphe-
nylacetylene under carbon monoxide pressure, while 5
is obtained from the reaction of 4 with sodium naph-
thalenide followed by [(η5-C5H5)Fe(CO)2Cl]. The X-ray
structures of 4 and 5 reveal the cobalt atoms to be
respectively chelated by lactonyl and cyclic anhydride
substituted vinylphosphines, so that 5 is formally derived
from 4 by insertion of CO into the lactonyl ring.
More often, however, the coupling reaction of alkynes
with phosphido-bridged species results in complexes
containing metallocyclic rings incorporating up to nine
atoms (for example complex 3).4,5
We now report that the reaction of diphenylacetylene
with [Co2(µ-PPh2)2(CO)6]6 under carbon monoxide pres-
sure results in coupling of phosphido, alkyne, and CO
fragments to yield a mononuclear cobalt complex [Co-
{PPh2CPhdCPhCOC(O)CPhCPh}(CO)2] (4) (Scheme 1).
Insertion of CO into the lactonyl ring of the chelating
substituted vinylphosphine ligand in 4 to give [Co{PPh2-
CPhdCPhCC(O)OC(O)CPhCPh}(CO)2] (5), which con-
tains an acid anhydride ring, can be achieved by
reaction of 4 with sodium naphthalenide followed by
[(η5-C5H5)Fe(CO)2Cl].
In tr od u ction
The reactions of alkynes with transition metal car-
bonyl complexes to give cyclic carbonyl-containing or-
ganic molecules, such as cyclopentadienones, cyclohep-
tatrienones, quinones, and lactones, are well docu-
mented.1 The organic molecules may be obtained free
or coordinated to a transition metal in a complex.
Cobalt carbonyl complexes are among the most active
in reactions of this type, and for example, the reaction
of an alkyne with [Co2(CO)8] followed by treatment with
CO at high temperature and pressure affords the
lactonyl complex 1.2 In a similar manner compounds
Resu lts a n d Discu ssion
Reaction of 4 equiv of diphenylacetylene with a freshly
prepared sample of [Co2(µ-PPh2)2(CO)6] in a sealed
vessel under an atmosphere of carbon monoxide at 80
atm and 385 K gave complex 4 in ca. 50% yield. Also
isolated from the reaction in lower yield were [Co3(µ-
PPh2)3(CO)6], [Co2{µ-PPh2CPhCPhC(O)}(µ-PPh2)(CO)4],
and [Co2{µ-PPh2CPhCPh}(µ-PPh2)(CO)4], all of which
have been characterized previously.6,7 Spectroscopic
data for complex 4 include three absorptions in the
carbonyl region of the infrared spectrum [νCO (CH2Cl2)
2032 s, 1984 s, 1741 m], a singlet resonance at δ -63.8
in the 31P{1H} NMR, and separate resonances corre-
sponding to the vinyl, lactonyl, and phenyl carbon atoms
of the chelating ligand in the 13C{1H} NMR spectrum
(see Experimental Section). This spectroscopic informa-
tion is not sufficient, however, to determine the precise
structure of 4. Crystallization of 4 by slow diffusion of
(4) Caffyn, A. J . M.; Mays, M. J .; Solan, G. A.; Braga, D.; Tiripicchio,
A.; Tiripicchio Camellini, M. Organometallics 1993, 12, 1876.
(5) (a) Barnett, B. L.; Kruger, C. Cryst. Struct. Commum. 1973, 2,
347. (b) Regragui, R.; Dixneuf, P. H.; Taylor, N. J .; Carty, A. J .
Organometallics 1984, 3, 814; 1990, 9, 2234. (c) Van Gastel, F.; Carty,
A. J .; Pellinghelli, M. A.; Tiripicchio A.; Sappa, E. J . Organomet. Chem.
1990, 385, C50. (d) Zolk, R.; Werner, H. J . Organomet. Chem. 1983,
252, C53; 1987, 337, 95. (e) Horton, A. D.; Mays, M. J .; Raithby, P. R.
J . Chem. Soc., Chem. Commun. 1985, 247. (f) Smith, W. F.; Taylor, N.
J .; Carty, A. J . J . Chem. Soc., Chem. Commun. 1976, 896. (g) Klingert,
B.; Rheingold, A. L.; Werner, H. Inorg. Chem. 1988, 27, 1354. (h)
Conole, G.; McPartlin, M.; Mays, M. J .; Morris, M. J . J . Chem. Soc.,
Dalton Trans. 1990, 2359. (i) Edwards, A. J .; Mart´ın, A.; Mays, M. J .;
Nazar, D.; Raithby, P. R.; Solan, G. A. J . Chem. Soc., Dalton Trans.
1993, 355.
such as 2 containing a coordinated quarternized phos-
phole ring can be prepared by the reaction of alkynes
with a phosphido-bridged cobalt carbonyl complex.3
X Abstract published in Advance ACS Abstracts, August 15, 1996.
(1) See: Organic Syntheses with Metal Carbonyls; Wender, I., Pino,
P., Eds.; Wiley: New York, 1968, 1987; Vols. 1 and 2. New Syntheses
with Carbon Monoxide; Farbe, J ., Ed.; Springer: Berlin, 1980. Car-
bonylation; Colquhoun, H. M., Thompson, D. J ., Twigg, M. V., Eds.;
Plenum: New York, 1991.
(2) (a) Sterberg, H. W.; Shukys, J . G.; Donne, C. D.; Markby, R.;
Friedel, R. A.; Wender, I. J . Am. Chem. Soc. 1959, 81, 2339. (b) Mills,
O. S.; Robinson, G. Inorg. Chim. Acta 1967, 1, 61.
(3) (a) Braga, D.; Caffyn, A. J . M.; J ennings, M. C.; Mays, M. J .;
Manojlovic-Muir, L.; Raithby, P. R.; Sabatino, P.; Woulfe, K. W. J .
Chem. Soc., Chem. Commun. 1989, 1401. (b) Manojlovic-Muir, L.;
Mays, M. J .; Muir, K.; Woulfe, K. W. J . Chem. Soc., Dalton Trans.
1992, 1531.
(6) Harley, A. D.; Guskey, G. J .; Geoffroy, G. L. Organometallics
1983, 2, 53.
(7) Caffyn, A. J . M.; Mays, M. J .; Solan, G. A.; Braga D.; Sabatino,
P.; Conole, G.; McPartlin, M.; Powell, H. R. J . Chem. Soc., Dalton
Trans. 1991, 3103.
S0276-7333(96)00150-1 CCC: $12.00 © 1996 American Chemical Society

4086 Organometallics, Vol. 15, No. 19, 1996
Notes
Sch em e 1. Syn th esis of th e La cton yl Com p lex 4 a n d In ser tion of CO in to th e La cton yl Rin g of 4 To Give 5
Ta ble 1. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for Com p lex 4
Co-P(1)
2.190(4)
Co-C(1)
1.855(15)
2.002(14)
2.172(13)
1.817(15)
1.094(18)
1.351(21)
1.470(16)
1.466(16)
1.474(14)
1.499(18)
1.423(15)
Co-C(2)
1.832(17) Co-C(5)
1.976(14) Co-C(7)
1.830(14) P(1)-C(31)
1.846(12) C(1)-O(1)
1.123(21) C(3)-C(4)
Co-C(6)
P(1)-C(3)
P(1)-C(51)
C(2)-O(2)
C(3)-C(21) 1.492(16) C(4)-C(5)
C(4)-C(41) 1.469(19) C(5)-C(6)
C(5)-O(3)
1.452(15) C(6)-C(7)
C(6)-C(11) 1.483(14) C(7)-C(8)
C(7)-C(61) 1.453(16) C(8)-O(3)
C(8)-O(4)
1.184(16) C-C(phenyl) 1.328(23)-1.448(24)
P(1)-Co-C(1)
C(1)-Co-C(2)
C(1)-Co-C(5)
P(1)-Co-C(6)
C(2)-Co-C(6)
P(1)-Co-C(7)
C(2)-Co-C(7)
C(6)-Co-C(7)
Co-P(1)-C(31)
Co-P(1)-C(51)
99.3(5)
100.6(7)
107.1(7)
107.2(3)
111.4(6)
146.3(3)
104.3(6)
41.3(4)
P(1)-Co-C(2)
P(1)-Co-C(5)
C(2)-Co-C(5)
C(1)-Co-C(6)
C(5)-Co-C(6)
C(1)-Co-C(7)
C(5)-Co-C(7)
Co-P(1)-C(3)
C(3)-P(1)-C(31)
C(3)-P(1)-C(51)
Co-C(1)-O(1)
98.9(5)
82.1(4)
151.7(5)
134.0(7)
43.2(5)
100.1(7)
65.9(5)
104.7(5)
105.0(6)
104.4(6)
177.8(15)
113.4(8)
123.1(4)
112.2(4)
C(31)-P(1)-C(51) 105.8(7)
Co-C(2)-O(2)
P(1)-C(3)-C(21)
C(3)-C(4)-C(5)
C(5)-C(4)-C(41)
Co-C(5)-C(6)
Co-C(5)-O(3)
C(6)-C(5)-O(3)
Co-C(6)-C(7)
Co-C(6)-C(11)
C(7)-C(6)-C(11)
Co-C(7)-C(8)
Co-C(7)-C(61)
C(8)-C(7)-C(61)
C(7)-C(8)-O(4)
C(5)-O(3)-C(8)
177.7(13) P(1)-C(3)-C(4)
122.2(11) C(4)-C(3)-C(21) 124.3(12)
116.3(12) C(3)-C(4)-C(41) 125.5(10)
118.1(12) Co-C(5)-C(4)
67.4(8)
107.4(7)
108.9(10) Co-C(6)-C(5)
76.5(7)
F igu r e 1. Molecular structure of [Co{PPh2CPhdCPhCOC-
(O)CPhCPh}(CO)2] (4) including the atom-numbering
scheme.
122.9(11)
128.0(9)
113.6(10)
69.3(8)
C(4)-C(5)-C(6)
C(4)-C(5)-O(3)
pentane into a dichloromethane solution of 4 at room
temperature generated orange single crystals suitable
for X-ray structural analysis. The molecular structure
of complex 4 is shown in Figure 1. Selected bond
distances and angles are listed in Table 1, and atomic
coordinates are given in the Supporting Information.
The structure consists of a single cobalt atom, coor-
dinated by two terminal carbonyl ligands and a 5-elec-
tron donor chelating ligand consisting of a lactonyl ring
substituted at C(5) by a vinylphosphine group. The
lactonyl portion of the ligand is η3-coordinated via
C(5)C(6)C(7) to the cobalt with the carbon-cobalt
distances being very similar [Co-C(5) 2.002(14), Co-
C(6) 1.976(14), Co-C(7) 2.172(13) Å]. The vinylphos-
phine arm of the lactonyl group, Ph2PCPhdCPh, ex-
tends round so as to coordinate via the phosphino group
to the cobalt atom [Co-P(1) 2.190(4) Å]. Mononuclear
cobalt carbonyl complexes containing η3-lactonyl groups,
[Co{RCH2COC(O)CR1CR2}(CO)3] (R ) H, CO2Et, CN,
CH2CH2OH; R1, R2 ) H, Et, t-Bu, CMe2OH), have been
previously prepared by different methods and charac-
terized on the basis of spectroscopic data.8
C(5)-C(6)-C(7)
101.3(8)
135.3(10) C(5)-C(6)-C(11) 124.9(10)
129.2(10) Co-C(7)-C(6)
99.1(8) C(6)-C(7)-C(8)
62.2(7)
107.3(10)
120.2(10) C(6)-C(7)-C(61) 127.4(9)
122.3(10) C(7)-C(8)-O(3)
133.8(12) O(3)-C(8)-O(4)
106.3(9)
107.0(10)
119.1(12)
lactonyl group has been converted to a cyclic anhydride
group, can be achieved in two steps. Addition of 2 equiv
of sodium naphthalenide to 4 in THF at room temper-
ature, followed by treatment with [(η5-C5H5)Fe(CO)2Cl],
results in the formation of 5 in moderate yield.
The IR spectrum in the νCO region of 5 is particularly
informative with four absorption bands, two corre-
sponding to terminal carbonyl bands (2045 s, 2001 s
cm-1) and two corresponding to ketonic bands (1740 s,
1703 s cm-1). The fast atom bombardment (FAB) mass
spectrum shows a molecular ion peak at 740 amu
corresponding to an increase of 28 amu compared to the
molecular ion peak found in the spectrum for 4. The
single-crystal X-ray structure for 5 is shown in Figure
2. Selected bond distances and angles are given in
Table 2.
Insertion of CO into the lactonyl portion of the
chelating ligand in 4 to give complex 5, in which the
The structure of complex 5 resembles that of 4 with
a single cobalt atom surrounded by two terminal car-
(8) Heck, R. F. J . Am. Chem. Soc. 1964, 81, 2819. Heck, R. F. U.S.
Pat. 1966, 3, 293, 295.

Notes
Organometallics, Vol. 15, No. 19, 1996 4087
Ta ble 2. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for Com p lex 5
Co(1)-C(102)
Co(1)-C(4)
Co(1)-C(5)
P(1)-C(1)
O(2)-C(7)
O(3)-C(7)
C(2)-C(3)
C(3)-C(7)
C(5)-C(6)
1.821(5) Co(1)-C(101)
1.980(4) Co(1)-C(3)
2.117(4) Co(1)-P(1)
1.845(4) O(1)-C(6)
1.400(5) O(2)-C(6)
1.212(5) C(1)-C(2)
1.512(6) C(3)-C(4)
1.485(7) C(4)-C(5)
1.824(5)
2.074(4)
2.204(1)
1.214(6)
1.421(5)
1.363(6)
1.468(6)
1.467(6)
1.472(7) C(101)-O(101) 1.139(6)
C(102)-O(102) 1.154(6) C-C(phenyl)
1.382(8)-1.421(7)
C(4)-Co(1)-C(3)
C(3)-Co(1)-C(5)
C(3)-Co(1)-P(1)
C(1)-P(1)-Co(1)
C(2)-C(1)-P(1)
C(4)-C(3)-C(7)
C(7)-C(3)-C(2)
C(7)-C(3)-Co(1)
C(3)-C(4)-C(5)
C(5)-C(4)-Co(1)
C(4)-C(5)-Co(1)
O(1)-C(6)-O(2)
O(2)-C(6)-C(5)
O(3)-C(7)-C(3)
42.4(2) C(4)-Co(1)-C(5)
71.1(2) C(4)-Co(1)-P(1)
41.8(2)
106.4(1)
148.1(1)
121.3(4)
118.4(4)
119.7(4)
65.4(2)
82.6(1) C(5)-Co(1)-P(1)
104.2(2) C(7)-O(2)-C(6)
111.9(3) C(1)-C(2)-C(3)
121.4(4) C(4)-C(3)-C(2)
114.7(4) C(4)-C(3)-Co(1)
106.1(3) C(2)-C(3)-Co(1)
112.3(4) C(3)-C(4)-Co(1)
74.1(2) C(4)-C(5)-C(6)
64.1(2) C(6)-C(5)-Co(1)
115.6(4) O(1)-C(6)-C(5)
119.3(4) O(3)-C(7)-O(2)
126.2(4) O(2)-C(7)-C(3)
118.1(3)
72.2(2)
119.4(4)
104.8(3)
125.1(4)
116.6(4)
117.2(4)
O(101)-C(101)-Co(1) 176.2(5) O(102)-C(102)-Co(1) 177.7(4)
Sch em e 2. P ossible Rea ction P a th w a y Accou n tin g
for th e In ser tion of CO in to th e La cton yl Rin g of 4
To Give 5
F igu r e 2. Molecular structure of [Co{PPh2CPhdCPhCC-
(O)OC(O)CPhCPh}(CO)2] (5) including the atom-number-
ing scheme.
bonyl ligands and by a chelating 5-electron donor ligand.
The nature of the 5-electron donating ligand in 5 differs
from that in 4 with a cyclic anhydride group η3-
coordinating to cobalt through C(3)C(4)C(5), while the
vinylphosphine arm, CPhdCPhPPh2, as in 4, wraps
around to complete the distorted octahedral coordination
at cobalt. The conversion of the lactone moiety in 4 to
a cyclic anhydride in 5 has only a minor effect on the
structural parameters, with the phosphorus-cobalt and
carbon-cobalt distances being similar [Co-P(1)
2.190(4) (4) vs Co(1)-P(1) 2.204(1) Å (5) and Co-C(5)
2.002(14), Co-C(6) 1.976(14), Co-C(7) 2.172(13) (4) vs
Co(1)-C(3) 2.074(4), Co(1)-C(4) 1.980(4), Co(1)-C(5)
2.117(4) Å (5)].
The mechanism by which a CO group inserts into a
C-O bond in 4 to give 5 is uncertain, but Scheme 2
shows a possible pathway involving the formation of a
dianionic intermediate A, in which cleavage of a carbon-
oxygen bond and generation of a metal-carbene unit
has occurred. A second dianionic intermediate B, in
which a divinylketene coordinates to cobalt, provides a
site for nucleophilic attack by the carboxylate oxygen.
Oxidation with [(η5-C5H5)Fe(CO)2Cl] then yields com-
plex 5. The formation of metal-ketenes have been
proposed as intermediates in the reactions of chromium-
carbene complexes (i) with alkynes to give hydroquinone
derivatives (the Do¨tz reaction)9 and (ii) with imines to
give â-lactams.10

4088 Organometallics, Vol. 15, No. 19, 1996
Notes
Ta ble 3. Cr ysta llogr a p h ic Da ta for th e Com p lexes
4 a n d 5
Exp er im en ta l Section
All reactions were carried out under a nitrogen atmosphere
using standard Schlenk techniques. Solvents were distilled
under nitrogen from appropriate drying agents and degassed
prior to use. Preparative thin-layer chromatography (TLC)
was carried out on commercial Merck plates with a 0.25 mm
layer of silica or on 1 mm silica plates prepared at the
University Chemical Laboratory, Cambridge, U.K. Column
chromatography was performed on Kieselgel 60 (70-230 mesh)
or (230-400 mesh). Products are given in order of decreasing
Rf values.
The instrumentation used to obtain spectroscopic data has
been described previously.11 Phosphorus-31 NMR chemical
shifts are given relative to P(OMe)3 with upfield shifts nega-
tive. All NMR spectra were recorded at 293 K. Unless
otherwise stated all reagents were obtained from commercial
suppliers, and the compound [Co2(µ-PPh2)2(CO)6] was prepared
by the literature method.6
Rea ction of [Co2(µ-P P h 2)2(CO)6] w ith Dip h en yla cety-
len e. A solution of the freshly prepared complex [Co2(µ-PPh2)2-
(CO)6] (0.500 g, 0.762 mmol) in toluene (50 mL) was charged
with 4 equiv of diphenylacetylene (0.543 g, 3.05 mmol), loaded
into a 100 mL Roth autoclave, pressurized to 80 atm with
carbon monoxide, and stirred overnight at 385 K. After
removal of the solvent under reduced pressure, the residue
was dissolved in the minimum quantity of dichloromethane
and adsorbed onto silica. The silica was pumped dry and
added to the top of a chromatography column. Elution initially
with hexane gave the green trinuclear species [Co3(µ-PPh2)3-
(CO)6] (0.014 g, 2%), and then elution with hexane-CH2Cl2
(1:1) gave the green complex [Co2(µ-PPh2CPhCPh)(µ-PPh2)(CO)4]
(0.018 g, 3%), a trace of [Co2{µ-PPh2CPhCPhC(O)}(µ-PPh2)-
(CO)4], and, on further elution with CH2Cl2, orange crystalline
[Co{µ-PPh2CPhCPhCOC(O)CPhCPh}(CO)2] (4) (0.270 g,
50%): IR (CH2Cl2) νCO ) 2032 s, 1984 s, 1741 m cm-1; 1H NMR
(CD2Cl2) δ 8.1-6.8 (m, Ph); 31P{1H} NMR (CDCl3) δ -63.8 [s,
Ph2PCPhCPh]; 13C{1H} NMR (CDCl3) δ 200.1 [d, 2J (PC) 10,
Ph2PCPhCPh], 199.5 (s, 2CO), 172.6 [d, 4J (PC) 4, COC(O)-
CPhCPh], 153.8 [d, 1J (PC) 28, Ph2PCPhCPh], 136-127 (m,
Ph), 110.1 [s, COC(O)CPhCPh], 97.9 [s, COC(O)CPhCPh], 64.1
[s, COC(O)CPhCPh]. Anal. Calcd for C44H30CoO4P: C, 71.06;
H 4.21; P, 4.35. Found: C, 71.36; H, 4.11; P, 4.66. FABMS
(m/e): 712 (M+) and M+ - nCO (n ) 1-3).
P r ep a r a tion of [Co{µ-P P h 2CP h CP h C(O)COC(O)CP h -
CP h }(CO)2] (5). A THF solution of sodium naphthalenide
was prepared by adding naphthalene (0.110 g, 0.86 mmol) to
sodium metal (0.019 g, 0.84 mmol) in THF (30 mL) and was
stirred until all the sodium had disappeared. The solution of
sodium naphthalenide was then canulated into a Schlenk flask
containing complex 4 (0.300 g, 0.42 mmol), dissolved in THF
(20 mL), and was stirred overnight at room temperature. To
this solution was added [(η5-C5H5)Fe(CO)2Cl] (0.176 g, 0.84
mmol), and the resultant brown solution was stirred for 3 h.
The solvent was removed under reduced pressure, and the
residue dissolved in the minimum quantity of CH2Cl2 was
4
5‚CH2Cl2
formula
fw
C44H30CoO4P
712
C46H32Cl2CoO5P
825.5
cryst system
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
Triclinic
P1h
Triclinic
P1h
9.737(4)
14.494(4)
16.801(6)
67.43(2)
76.98(3)
83.85(3)
1985(2)
2
10.165(2)
11.936(2)
17.692(4)
73.13(3)
86.63(3)
75.99(3)
1993(1)
2
Z
D
calcd, g/cm3
1.132
1.376
F(000)
700
848
cryst color and habit
cryst dimens, mm
µ, mm-1
red block
red block
0.25 × 0.31 × 0.34 0.41 × 0.32 × 0.31
0.508
2θ-θ
0.651
scan type
radiation
temp, K
Mo KR
290
Mo KR
153
θ range, deg
5-45
5-45
scan mode
ω/2θ
ω/2θ
reflcns, measd
no. of unique reflns
no. of reflns obsda
refinement method
5744
5195
2782 [I > 5.0σ(I)]
full-matrix
least squares
291
4625
4587
4581 [I > 2σ(I)]
full-matrix
least squares
496
no. of params
R
Rw
0.0860
0.1204
0.0486
0.1336
loaded onto the base of TLC plates. Elution with CH2Cl2 gave
[(η5-C5H5)2Fe2(CO)4] [0.201 g, 68% based on η5-C5H5)Fe(CO)2-
Cl], unreacted 4 (0.03 g, 10%), and [Co{µ-PPh2CPhCPhC(O)-
COC(O)CPhCPh}(CO)2] (5) (0.059 g, 19%): IR (CH2Cl2) νCO
)
2045 s, 2001 s, 1740 s, 1703 s cm-1; 1H NMR (CD2Cl2) δ 8.1-
6.8 (m, Ph); 31P{1H} NMR (CDCl3) δ -72.7 [s, Ph2PCPhCPh].
Anal. Calcd for C45H30CoO5P: C, 71.06; H 4.21; P, 4.35.
Found: C, 71.36; H, 4.11; P, 4.66. FABMS (m/e): 740 (M+)
and M+ - nCO (n ) 1-3).
Cr ysta llogr a p h ic An a lysis. Suitable single crystals of
complexes 4 and 5 for X-ray analysis were obtained by slow
diffusion of pentane into dichloromethane solutions at 293 K
(4) and 273 K (5). Crystal data are reported in Table 3. Data
were collected on a Siemens R3m/V (4) and on a Stoe 4-circle
diffractometer equipped with an Oxford Cryostream crystal
cooling device (5).
Ack n ow led gm en t. We thank the EPSRC (to G.A.S.)
for financial support.
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
structure determination data, atomic coordinates and U
values, anisotropic thermal parameters, and bond lengths and
angles for complexes 4 and 5 (16 pages). Ordering information
is given on any current masthead page.
(9) Wulff, W. D. In Comprehensive Organic Synthesis; Trost, B. M.,
Fleming, I., Paquette, L. A., Eds.; Pergamon: Oxford, U.K., 1991; Vol.
5, pp 1065-1113 and references therein.
(10) Hegedus, L. S.; de Weck, G; D’Andrea, S. J . Am. Chem. Soc.
1988, 110, 2122 and references therein.
OM960150B
(11) Caffyn, A. J . M.; Mays, M. J .; Raithby, P. R. J . Chem. Soc.,
Dalton Trans. 1991, 2349.
(12) Sheldrick, G. M. SHELX-76 program for crystal structure
determination, University of Cambridge, 1976.