Reaction of acyl(hydrido)cobalt(III) complexes with (2-diphenylphosphanyl) phenol and influence of chelating ligands containing hard/soft donor atoms on the stability of cobalt complexes

Article abstract of DOI:10.1021/om0489960

(Acylphenolato)hydridocobalt(III) complexes by reaction with (2-diphenylphosphanyl) phenol deliver (2-diphenylphosphanyl)phenolatocobalt(III) complexes with a 2-acylphenolato chelating ligand as co-ligand (complexes 2, 4-6, and 10-12). Depending on the substituents in the chelating ligands trans/cis-isomers were detected by NMR and IR spectroscopy. Complex 2 was shown by X-ray crystallography to attain an octahedral structure. Under specific conditions substituted (2-hydroxymethyl)phenol and a (2-diphenylphosphanyl)- phenolatocobalt(I) complex were obtained. A likely reaction route is presented. Influences of chelating ligands containing hard/soft donor atoms on the stability of the cobalt complexes will be discussed.

Full text of DOI:10.1021/om0489960

2612
Organometallics 2005, 24, 2612-2616
Reaction of Acyl(hydrido)cobalt(III) Complexes with
(2-Diphenylphosphanyl)phenol and Influence of
Chelating Ligands Containing Hard/Soft Donor Atoms on
the Stability of Cobalt Complexes
Hongjian Sun,*,† Xiaoyan Li,† Hans-Friedrich Klein,‡ Ulrich Flo¨rke,§ and
Hans-Ju¨rgen Haupt§
School of Chemistry and Chemical Engineering, Shandong University, Shanda Nanlu 27,
250100 Jinan, People’s Republic of China, Eduard-Zintl-Institut fu¨r Anorganische und
Physikalische Chemie der Technischen Universita¨t Darmstadt, Petersenstrasse 18,
64287 Darmstadt, Germany, and Anorganische und Analytische Chemie der Universita¨t
Paderborn, Warburger Strasse, 33098 Paderborn, Germany
Received December 17, 2004
(Acylphenolato)hydridocobalt(III) complexes by reaction with (2-diphenylphosphanyl)
phenol deliver (2-diphenylphosphanyl)phenolatocobalt(III) complexes with a 2-acylphenolato
chelating ligand as co-ligand (complexes 2, 4-6, and 10-12). Depending on the substituents
in the chelating ligands trans/cis-isomers were detected by NMR and IR spectroscopy.
Complex 2 was shown by X-ray crystallography to attain an octahedral structure. Under
specific conditions substituted (2-hydroxymethyl)phenol and a (2-diphenylphosphanyl)-
phenolatocobalt(I) complex were obtained. A likely reaction route is presented. Influences
of chelating ligands containing hard/soft donor atoms on the stability of the cobalt complexes
will be discussed.
Introduction
(2-Diphenylphosphanyl)phenol and its derivatives are
weakly [P,O]-chelating ligands containing an acidic OH
function.1,2 If there is no steric hindrance, the phospho-
rus atom can coordinate to the metal center. Deproto-
nated (2-diphenylphosphanyl)phenol is considered to be
an anionic chelating ligand of increased strength.
Ligand systems that are used as catalysts in the shell
higher olefin process (SHOP)3 for oligomerization of
ethene or R-olefins usually contain a [P,O]-chelating
part and nickel as central atom (Figure 1). The organic
part serves to stabilize the catalyst, while the chelating
part controls the catalytic activity and selectivity. The
SHOP process, with over one million ton capacity, is one
of the largest applications of homogeneous catalysis by
a transition metal compound.
A recent account by Heinicke et al. summarizes the
development concerning the syntheses and structural
aspects of neutral and cationic organonickel and pal-
ladium (2-phosphanyl)phenol(ate) complexes and cata-
lysts for ethylene-coupling reactions.4 Klein and co-
workers reported on the synthesis and characterization
of cobalt complexes containing chelating (2-diphenylphos-
phanyl)phenolato ligands.2 They obtained cobalt(I) com-
plexes containing one chelating ligand and cobalt(II)
complexes bearing two chelating ligands.
Figure 1.
Hydrido compounds play a central role among transi-
tion metal complexes. According to a widely accepted
mechanism for the hydroformylation process given by
Heck and Breslow, the hydridocobalt compound is a
precatalyst.5 Formation of a Co-H bond is achieved
through oxidative addition. Thermodynamically it is
unfavorable to cleave C-H bonds at a cobalt center
because the sum of the Co-C and Co-H bond energies
is not sufficient to account for breaking a C-H bond.6
Reactions of this type have been observed for the heavier
congeners of cobalt for which bond energies are larger.
There are reports of several reactions that give products
indicating oxidative addition of C-H bonds to cobalt.7
However, hydridocobalt complexes in these reactions are
postulated only as intermediates and were not experi-
mentally isolated. So far few examples of hydridocobalt-
(III) complexes are known.
Acyl(hydrido)cobalt species were postulated as car-
bonylcobalt intermediates in the catalytic cycle.8 In 1998
Klein and co-workers reported on acyl(hydrido)cobalt-
† Shandong University.
‡ Technischen Universita¨t Darmstadt.
§ Universita¨t Paderborn.
(1) Brand, A. Doctoral thesis, Technische Universita¨t Darmstadt,
1998.
(5) Heck, R. F.; Breslow, D. S. J. Am. Chem. Soc. 1961, 4023.
(6) Halper, J. Inorg. Chim. Acta 1985, 100, 41.
(7) Habadie, N.; Dartiguenave, M.; Dartiguenave, Y.; Britten, J. F.;
Beauchamp, A. L. Organometallics 1989, 81, 2564.
(8) Parshall, G. W.; Ittel, S. D. Homogeneous Catalysis, 2nd ed.;
Wiley: New York, 1992; p 109.
(2) Klein, H.-F.; Brand, A.; Cordier, G. Z. Naturforsch. 1998, 53b,
307.
(3) Kaim, W. Angew. Chem., Int. Ed. Engl. 1990, 29, 235.
(4) Heinicke, J.; Peulecke, N.; Koehler, M.; He, M.; Kaim, W. J.
Organomet. Chem. 2004, in press.
10.1021/om0489960 CCC: $30.25 © 2005 American Chemical Society
Publication on Web 04/19/2005

Stability of Cobalt Complexes
Organometallics, Vol. 24, No. 11, 2005 2613
(III) complexes, which are stabilized by a (2-acyl)-
phenolato chelating ligand and supporting trimethyl-
phosphine.9 We know that in the molecule [CoH(CO)4]
electrons flow from the hydrogen atom to the cobalt
center because of the strong back-bonding between the
CO ligands and the cobalt atom. Therefore a most
impressive aspect of the chemistry of [CoH(CO)4] is its
acidity.10 By contrast, the hydrogen atoms in the
thermally stable acyl(hydrido)cobalt(III) complexes bear
a partial negative charge.9 Studies on their properties
and reactions confirmed this inference from spectros-
copy. Reactions with perchloric, hydrochloric, acetic acid,
alkyl halides, salicylaldehyde, or malondialdhyde pro-
ceed as with metal hydrides.11 Acyl(phenolato)hydri-
docobalt(III) complexes upon reaction with 2-nitrophenol
or 2-nitronaphthol eliminate dihydrogen and afford
2-nitrophenolato or 2-nitronaphtholato cobalt(III) com-
pounds.12 In addition, formal insertion of phenylethyne
into the Co-H function was found to give vinylcobalt-
(III) complexes.13
Here we report on our recent progress in studying the
chemistry of acyl(hydrido)cobalt(III) complexes. In this
account reactions between acyl(hydrido)cobalt(III) com-
plexes and several (2-diphenylphosphanyl)phenols are
described. The products obtained contain two chelating
ligands. With respect to the positions of two trimeth-
ylphosphine ligands cis/trans-isomers are found in the
products of some of the reactions. A crystal structure
analysis by X-ray diffraction confirmed their molecular
geometry. As byproducts a cobalt(I) complex containing
a monochelating ligand and substituted (2-hydroxy-
methyl)phenol was isolated. A likely formation route
will be discussed.
as a doublet for two trans-trimethylphosphines, and a
triplet for the diphenylphosphanyl group.
The molecular structure of 2 (Figure 2) shows a
hexacoordinate cobalt atom and three P-donor atoms
lying in a plane, while one phenolato-O donor and one
enolato-O donor and an acyl group are arranged in a
plane perpendicular to the first. In opposite position to
the acyl group the Co-O distance (Co1-O3 ) 2.0346-
(4) Å) is larger than that opposite to the diphenylphos-
phanyl group (Co1-O2 ) 1.9414(13) Å), indicating a
stronger trans-influence in the former.
Analogous reactions according to eq 2 have been
carried out with mer-hydrido(3-tert-butyl-5-methyl-2-
oxobenzoyl)tris(trimethylphosphine)cobalt(III) (3) and
(2-diphenylphosphanyl)phenol, (4-methyl-2-diphenylphos-
phanyl)phenol, and (4-methoxy-2-diphenylphosphanyl)-
phenol. The new cobalt(III) complexes 4-6 as main
products (see below) containing two chelating ligands,
one 2-acylphenolato ligand and one (2-diphenylphos-
phanyl)phenolato ligand, and two trans-trimethylphos-
phine ligands were shown by spectroscopy in solution
to attain a configuration similar to complex 2.
Results and Discussion
The (2-acylphenolato)hydridocobalt(III) complex 1 by
reaction with (2-diphenylphosphanyl)phenol afforded
the six-coordinate cobalt(III) complex 2 (eq 1).
However, under the same conditions reactions of the
(2-acylphenolato/enolato)hydrido cobalt(III) complexes
7-9 with (2-diphenylphosphanyl)phenol afforded cis-
products cis-10-cis-12 (eq 3) besides trans-10-trans-
12, corresponding with product 2 in eq 1 and products
4-6 in eq 2. Well-resolved H and 31P NMR spectra
clearly show the presence of these two isomers in
solutions.
1
The (2-diphenylphosphanyl)phenolatocobalt(III) com-
plex 2 forms orange cubic crystals (from pentane), which
are air-stable and decompose above 160 °C. In the IR
spectra the conspicuous ν(Co-H) absorption of the
starting complex is absent. The 1H NMR spectrum
indicates the presence of 2 by the expected pattern of
PCH3 signals as a virtual triplet for two trans-trimeth-
ylphosphine groups. 31P data clearly show one signal
The reaction of complex 3 with (2-diphenylphospha-
nyl)phenol (eq 2) produced not only complex 4 but also
complex 14 and (2-tert-butyl-6-hydroxymethyl-4-meth-
yl)phenol as byproducts. The first step in the proposed
mechanism (Figure 3) consists of a substitution of the
coordinated phenoxy group of the 2-acylphenolato chelat-
ing ligand by that of a (2-diphenylphosphanyl)phenolato
chelating ligand. Complex 13 is a likely intermediate.
The (2-diphenyl phosphanyl)phenolato cobalt(I) complex
14 originates through reductive elimination from com-
plex 13. In a parallel reaction the hydridocobalt complex
3 reacts with (2-diphenylphosphanyl)phenol under par-
ticipation of regenerated 3-tert-butyl-5-methylsalicyl-
saldehyde to afford the bis-chelate complex 4 together
(9) Klein, H.-F.; Haller, S.; Sun, H.; Li, X.; Jung, T.; Ro¨hr, C.; Flo¨rke,
U.; Haupt, H.-J. Z. Naturforsch. 1998, 53b, 587.
(10) Moore, E. J.; Sullivan, J. M.; Norton, J. R. J. Am. Chem. Soc.
1986, 108, 2257.
(11) Klein, H.-F.; Haller, S.; Sun, H.; Li, X.; Jung, T.; Ro¨hr, C.;
Flo¨rke, U.; Haupt, H.-J. Z. Naturforsch. 1998, 53b, 856.
(12) Klein, H.-F.; Li, X.; Flo¨rke, U.; Haupt, H.-J. Inorg. Chim. Acta
2003, 342, 179.
(13) Klein, H.-F.; Li, X.; Flo¨rke, U.; Haupt, H.-J. Z. Naturforsch.
2000, 55b, 707.

2614 Organometallics, Vol. 24, No. 11, 2005
Sun et al.
Figure 2. Molecular structure of 2. Selected distances (Å)
and angles (deg): Co1-C1 1.919(2), Co1-O2 1.9494(13),
Co1-O3 2.0346(14), Co1-P1 2.2181(5), Co1-P2 2.2688-
(6), Co1-P3 2.2496(6), O1-C1 1.226(2), O2-C7 1.312(2),
C2-C7 1.357(3); C1-Co1-O3 175.00(7), C1-Co1-O2 85.32-
(8), O2-Co1-O3 89.69(6), C1-Co1-P1 99.66(6), O2-Co1-
P1 174.89(5), O3-Co1-P1 85.32(4), C1-Co1-P3 87.84(7),
O2-Co1-P3 86.25(5), O3-Co1-P3 92.00(5), P1-Co1-P3
95.02(2), C1-Co1-P2 94.94(6), O2-Co1-P2 82.77(5), O3-
Co1-P2 84.25, P1-Co1-P2 95.60(2), P2-Co1-P3 168.41-
(2).
with (2-tert-butyl-6-hydroxymethyl-4-methyl)phenol, by
hydrogen transfer to 3-tert-butyl-5-methylsalicylalde-
hyde. In the reaction mixture complex 14 and 2-tert-
butyl-6-hydroxymethyl-4-methylphenol were identified
by NMR. Analoguous complexes of 14 can also be
prepared either by reaction of CoMe(PMe3)4 with (2-
diphenylphosphanyl)phenol (eq 4) or by a two-step-
method (eq 5).1 From the reactions according to eq 3
complex 14 could also be isolated.
Figure 3.
afforded a (2-nitrosophenolato)cobalt(I) complex. Recent
research by Li revealed that the acyl(hydrido)cobalt(III)
complex 3 reacts with (2-diphenylphosphanyl)thiophenol
to afford a (2-diphenylphosphanyl)thiophenolatocobalt-
(I) complex exclusively.16 In this reaction no formation
of an analoguous cobalt(III) product with two chelating
ligands was indicated. This formal substitution reaction
is very fast, and the soft/soft chelating [P,S] ligand
appears to stabilize the corresponding cobalt(I) complex
much better than any type of [P,O] ligand in the other
cobalt(I) complexes in Figure 4. Therefore for the
formation of (2-tert-butyl-6-hydroxymethyl-4-methyl)-
In earlier work12 we had been able to obtain only cis/
trans-cobalt(III) complexes with two chelating ligands;
that is, one 2-acylphenolato ligand and one 2-nitrophe-
nolato ligand were coordinated in the reaction of an acyl-
(hydrido)cobalt(III) complex with 2-nitrophenol. No (2-
nitrophenolato)cobalt(I) complex was detected. Cor-
respondingly 2-hydroxymethylphenol was also absent.
According to the HSAB rule14 a (phosphanylphenolato)-
cobalt(I) complex is more stable than a nitrophenolato-
cobalt(I) complex because a nitro-[O]-donor is much
harder than a P-donor. In fact a (2-nitrophenolato)-
cobalt(I) complex could not be verified by experiment.15
Instead, the reaction of CoMe(PMe3)4 with 2-nitrophenol
(15) Klein, H.-F.; Schmidt, A.; Flo¨rke, U.; Haupt, H.-J. Inorg. Chim.
Acta 2003, 342, 171.
(16) Li, X. Unpublished results.
(14) Pearson, R. G. J. Am. Chem. Soc. 1963, 85, 3533.

Stability of Cobalt Complexes
Organometallics, Vol. 24, No. 11, 2005 2615
afforded orange crystals, which were found suitable for X-ray
diffraction: yield 0.18 g of 2 (17%), mp (dec) > 160 °C. Anal.
Calcd for C31H40CoO3P3 (mol wt 612.5): C, 60.79; H, 6.58.
Found: C, 60.56; H, 6.75. IR (Nujol mull, 2600-1500 cm-1):
1
1583 s, ν(CdO); 1560 s, 1537 s, ν(CdC). H NMR (300 MHz,
2
THF-d8, 300 K): δ(PCH3) 0.68 (t′, | J(PH) + 4J(PH)| ) 8.7 Hz,
18 H); δ(CH2) 1.51 (m, 2 H); δ(CH2) 1.62 (m, 2 H), 2.24 (m, 4
H); δ(CH) 6.50 (m, 1 H), 6.84 (m, 1 H), 7.20 (m, 1 H), 7.28 (m,
6 H), 7.49 (m, 1 H), 8.27 (m, 4 H). 13C NMR (75.4 MHz, THF-
Figure 4.
1
d8, 300 K): δ(PCH3) 10.0 (t′, | J(PC) + 3J(PC)| ) 26.4 Hz);
phenol the soft/hard (2-diphenyl phosphanyl)phenolato
ligand plays an important role in the hydrogen transfer
reaction.
δ(CH2) 21.4, 21.8, 22.1, 22.4; δ(CH) 109.2, 120.2, 125.8, 125.9,
127.2, 130.5, 130.6, 130.7, 132.7; δ(CO) 170.1; δ(CCO) 218.3.
31P NMR (81.0 MHz, THF-d8, 213 K): δ(PCH3) 17.2 (d, 2J(PP)
2
) 70.6 Hz, 2 P); δ(PC6H5) 25.1 (t, J(PP) ) 70.6 Hz, 1 P).
Synthesis of (3-tert-Butyl-5-methyl-2-oxobenzoyl)(2-
diphenylphosphanylphenolato)bis(trimethylphosphine)-
cobalt(III) (4). A sample of 0.61 g (1.28 mmol) of mer-
hydrido(3-tert-butyl-5-methyl-2-oxobenzoyl)tris(trimethyl-
phosphine) cobalt(III) (3) and 0.37 g (1.33 mmol) of (2-
diphenylphosphanyl)phenol in 20 mL of THF after 18 h at
room temperature formed a dark red solution. The volatiles
were removed in vacuo, and the resulting solid was extracted
with pentane and diethyl ether, respectively. Crystallization
at -27 °C afforded orange microcrystals of 4: yield 0.094 g
(11%), mp (dec) > 190 °C. A second crystallization afforded
orange crystals of complex 14: yield 0.20 g (28%), mp (dec) >
110 °C. 4: Anal. Calcd for C36H46CoO3P3 (mol wt 678.6): C,
63.72; H, 6.83. Found: C, 63.66; H, 7.01. IR (Nujol mull, 2600-
l570 cm-1): 1609 s, 1582 s, ν(CdO); 1537m, ν(CdC). 1H NMR
Conclusion
Combination of cobalt with anionic phenolate as hard
oxygen donor and anionic acyl or neutral diarylphos-
phino groups as soft carbon or phosphor donor function
in ortho-positions of an aromatic ring generates two five-
membered chelate rings with closely related geometry.
Under the same experimental conditions different sub-
stituents at the aromatic ring of chelating ligands, e.g.,
2-acylphenolato and (2-diphenylphosphanyl)phenolato
ligands, give rise to products with different ratios of
trans/cis-isomers. In the generation of complexes 4 and
10-12 the five-coordinate cobalt(I) complex 14 was
identified (Figure 3). This fact implies the liberation of
(3-tert-butyl-5-methyl)salicylaldehyde, which is hydro-
genated in situ by complex 3 to give 2-tert-butyl-6-
hydroxymethyl-4-methylphenol. This hydrogen transfer
reaction proceeds in the presence of (2-diphenylphos-
phanyl)phenol, which eventually winds up in complex
4. This multistep process appears to be controlled by
the chelating ligands at the cobalt center and is favored
by the strongly donating trimethylphosphine ligands.
2
(300 MHz, THF-d8, 300 K): δ(PCH3) 0.67 (t′, | J(PH) + 4J(PH)|
) 8.9 Hz, 18H); δ[C(CH3)3] 1.46 (s, 9 H); δ(CCH3) 2.19 (s, 3
H); δ(CH) 6.54-8.26 (m, 16 H). 13C NMR (75.4 MHz, THF-d8,
1
300 K): δ(PCH3) 13.1 (t′, | J(PC) + 3J(PC)| ) 27.7 Hz); δ(CH3)-
20.0; δ[C(CH3)3] 31.0; δ[C(CH3)3] 34.9; δ(CH) 112.0, 112.1,
118.2, 122.2, 122.3, 128.2, 128.3, 129.8, 131.4, 133.0, 133.2,
133.3, 134.3; δ(C)110.7, 121.4, 135.9, 136.8, 137.2, 138.0, 176.0,
179.6. 31P NMR (81.0 MHz, THF-d8, 300 K): δ(PCH3) 3.2 (d,
2J(PP) ) 62.8 Hz, 2P); δ(PC6H5)19.2 (s(br), 1 P). 14: Anal.
Calcd for C27H41CoOP4 (mol wt 564.4): C, 57.46; H, 7.32.
Found: C, 57.66; H, 7.11. IR (Nujol mull, 2600-l570 cm-1):
1580 m ν(CdC). 1H NMR (300 MHz, THF-d8, 300 K): δ(PCH3)-
Experimental Section
3
1.19 (s, 27 H); δ(CH) 6.07 (t, J(HH) ) 8.0 Hz, 1 H), 6.33 (d,
3J(HH) ) 8.0 Hz, 1 H), 6.63 (t, 3J(HH) ) 8.0 Hz, 1 H), 6.67 (d,
3J(HH) ) 8.0 Hz, 1 H), 7.16-7.75 (m, 10 H). 13C NMR (75.4
MHz, THF-d8, 300 K): δ(PCH3) 19.7; δ(CH) 110.8, 116.4, 126.2,
126.3, 127.5, 130.6, 132.3; δ(CH) 141.8. 31P NMR (81.0 MHz,
General Procedures and Materials. Standard vacuum
techniques were used in manipulations of volatile and air-
sensitive material. Solvents were dried by known procedures
and used freshly distilled. Melting points/decomposition tem-
peratures: sealed capillaries, uncorrected values. Literature
methods were applied in the preparation of (2-acylphenolato-
hydrido)cobalt compounds,9 (2-diphenylphosphanyl)phenol, (4-
methyl-2-diphenylphosphanyl)phenol, and (4-methoxy-2-di-
phenylphosphanyl)phenol.17 IR: Nujol mulls between KBr
disks, Bruker spectrophotometer type FRA 106. 1H and 13C
NMR spectra (300 and 75 MHz, respectively) were recorded
with a Bruker ARX-300 spectrometer; 31P NMR spectra (81
MHz), with a Bruker AM-200 instrument. 13C and 31P NMR
resonances were obtained with broad-band proton decoupling.
C, H analyses were carried out in a German ELEMNTAR
Vario ELIII analyzer.
Synthesis of mer-(1-Carbonyl-2-oxo-cyclohexenediyl)-
(2-diphenylphosphanylphenolato)bis(trimethylphos-
phine)cobalt(III) (2). mer-Hydrido(1-carbonyl-2-oxo-cyclo-
hexenediyl)tris(trimethylphosphine)cobalt(III) (1) (0.71 g, 1.70
mmol) was dissolved in 30 mL of THF. To this solution was
added 0.48 g (1.73 mmol) of (2-diphenylphosphanyl)phenol in
20 mL of THF at -80 °C. The mixture was warmed to 20 °C
and stirred for 18 h. During this period the reaction solution
turned red. Evaporation of the filtrate under vacuum followed
by washing with pentane resulted in an orange solid, which
was extracted with diethyl ether. Crystallization at -27 °C
THF-d8, 213 K): δ(PCH3) -6.1 (dd,
2J(PP) ) 111 Hz,
trans
2J(PP) ) 57 Hz, 2P), 31.1 (dd, cis2J(PP) ) 57 Hz, 1P); δ(PC6H5)
cis
42.5 (dt,
2J(PP) ) 111 Hz, 2J(PP) ) 57 Hz, 1P).
trans
cis
Synthesis of (3-tert-Butyl-5-methyl-2-oxobenzoyl)(4-
methyl-2-diphenylphosphanylphenolato)bis(trimeth-
ylphosphine)cobalt(III) (5). A sample containing 0.70 g
(1.46 mmol) of mer-hydrido(3-tert-butyl-5-methyl-2-oxoben-
zoyl)tris(trimethylphosphine)cobalt(III) (3) and 0.43 g (1.48
mmol) of (4-methyl-2-diphenylphosphanyl)phenol in 50 mL of
THF after 18 h at room temperature formed a dark brown
solution. The volatiles were removed in vacuo, and the result-
ing solid was extracted with pentane. Crystallization at -27
°C afforded orange microcrystals: yield 0.080 g of 5 (8%), mp
(dec) > 170 °C. Anal. Calcd for C37H48CoO3P3 (mol wt 692.6):
C, 64.16; H, 6.98. Found: C, 63.86; H, 7.09. IR (Nujol mull,
2600-l570 cm-1): 1605 s, 1586 s, ν(CdO); 1546 m, ν(CdC).
2
1H NMR (300 MHz, THF-d8, 300 K): δ(PCH3) 0.66 (t′, | J(PH)
+
4J(PH)| ) 8.9 Hz, 18 H); δ[C(CH3)3] 1.45 (s, 9 H); δ(CH3)
2.19 (s, 3 H), 2.28 (s, 3 H); δ(CH) 6.75-8.26 (m, 15 H). 13C
1
NMR (75.4 MHz, THF-d8, 300 K): δ(PCH3) 12.4 (t′, | J(PC) +
3J(PC)| ) 27.7 Hz); δ(CH3) 19.3, 19.4; δ[C(CH3)3 30.3; δ[
C(CH3)3] 33.7; δ(CH) 117.4, 127.3, 128.2, 129.0, 130.6, 132.5,
132.7, 133.8; δ(C) 117.9, 133.8, 134.4, 136.4; δ(CO) 176.4;
δ(CCO) 202.7. 31P NMR (81.0 MHz, THF-d8, 300 K): δ(PCH3)
5.3 (s(br), 2 P); δ(PC6H5) 21.4 (s(br), 1 P).
(17) Dal, A. Doctoral thesis, Universita¨t Greifswald, 1998.

2616 Organometallics, Vol. 24, No. 11, 2005
Sun et al.
Synthesis of (3-tert-Butyl-5-methyl-2-oxobenzoyl)(4-
methoxy-2-diphenylphosphanylphenolato)bis(trimethyl-
phosphine)cobalt(III) (6). A sample containing 0.66 g (1.38
mmol) of mer-hydrido(3-tert-butyl-5-methyl-2-oxobenzoyl)tris-
(trimethylphosphine)cobalt(III) (3) and 0.40 g (1.30 mmol) of
(4-methoxy-2-diphenylphosphanyl)phenol in 40 mL of THF
after 18 h at room temperature formed a dark red solution.
The volatiles were removed in vacuo, and the resulting solid
was extracted with diethyl ether. Crystallization at -27 °C
afforded orange microcrystals: yield 0.12 g of 6 (13%), mp (dec)
>205 °C. Anal. Calcd for C37H48CoO4P3 (mol wt 708.6): C,
62.72; H, 6.83. Found: C, 62.69; H 7.01. IR (Nujol mull, 2600-
l570 cm-1): 1606 s, 1588 s, ν(CdO); 1553 m ν(CdC). 1H NMR
Synthesis of (3-Methoxy-2-oxobenzoyl)(2-diphenylphos-
phanylphenolato)bis(trimethylphosphine)cobalt(III) (12).
A sample containing 2.25 g (5.13 mmol) of mer-hydrido(3-
methoxy-2-oxobenzoyl)tris(trimethylphosphine)cobalt(III) (9)
and 1.42 g (5.12 mmol) of (2-diphenylphosphanyl)phenol in 80
mL of THF after 18 h at room temperature formed a dark red-
brown solution. The volatiles were removed in vacuo, and the
resulting solid was extracted first with pentane and second
with diethyl ether. Crystallization from pentane at -27 °C
afforded orange microcrystals: yield 0.50 g of 12 (15%); mp
(dec) > 230 °C. Crystallization from diethyl ether gave complex
14 (1.50 g, 51.9%). 12: Anal. Calcd for C32H38CoO4P3 (mol wt
638.5): C, 60.19; H, 6.00. Found: C, 60.32; H 6.01. IR (Nujol,
2600-l570): 1615 s, 1578 s, ν(CdO); 1537 m ν(CdC). 1H NMR
(300 MHz, THF-d8, 297 K): cis/trans-12 ) 96/4. cis-12:
2
(300 MHz, THF-d8, 300 K): δ(PCH3) 0.67 (t′, | J(PH) + 4J(PH)|
) 8.9 Hz, 18 H); δ [C(CH3)3] 1.45 (s, 9 H); δ(CH3) 2.19 (s, 3 H);
δ(OCH3) 3.72 (s, 3 H); δ(CH) 6.86-8.29 (m, 15 H). 13C NMR
2
4
δ(PCH3) 1.22 (dd, J(PH) ) 10.3 Hz, J(PH) ) 1.4 Hz, 9 H),
1
2
(75.4 MHz, THF-d8, 300 K): δ(PCH3) 11.2 (t′, | J(PC) + 3J(PC)|
0.92 (d, J(PH) ) 9.9 Hz, 9 H); δ(OCH3) 3.21 (s, 3 H); trans-
2
) 26.4 Hz,); δ(CH3) 18.1; δ(CCH3) 29.2, δ(CCH3) 33.0; δ(OCH3)
51.7; δ(CH) 114.0, 116.3, 120.5, 120.6, 120.7, 126.3, 126.4,
127.9, 131.4, 131.5 (CH); δ(C) 104.1, 118.4, 132.1, 133.2, 134.0,
144.1, 144.2, 172.9, 175.0. 31P NMR (81.0 MHz, THF-d8, 300
K): δ(PCH3) 5.3 (d, 2J(PP) ) 75.3 Hz, 2 P); δ(PC6H5) 22.2 (s(br),
1 P).
12: δ(PCH3) 0.63 (t′, | J(PH) + 4J(PH)| ) 8.9 Hz, 18 H),
δ(OCH3) 3.78 (s, 3H); without assignment: δ(CH) 5.96-8.28
(m). 13C NMR (75.4 MHz, THF-d8, 300 K): δ(PCH3) 10.0 (t′,
1
| J(PC) + 3J(PC)| ) 26.4 Hz), 11.6 (d, 1J(PC) ) 25.7 Hz), 13.8
(d, 1J(PC) ) 26.4 Hz), δ(OCH3) 53.1; δ(CH) 110.2, 110.7, 110.8,
111.0, 113.2, 120.3, 124.7, 124.8, 126.6, 127.3, 127.4, 128.5,
131.1, 132.1, 132.3, 134.8, 150.3; δ(CO) 166.6, 178.4. 31P NMR
Synthesis of (1-Carbonyl-2-oxo-1,2-diphenylethene-
diyl)(2-diphenylphosphanylphenolato)bis(trimethyl-
phosphine)cobalt(III) (10). A sample containing 2.14 g (4.19
mmol) of mer-hydrido(1-carbonyl-2-oxo-1,2-diphenylethene-
diyl)tris(trimethylphosphine)cobalt(III) (7) and 1.18 g (4.26
mmol) of (2-diphenylphosphanyl)phenol in 80 mL of THF after
18 h at 20 °C formed a brown solution. The volatiles were
removed in vacuo, and the resulting solid was extracted with
pentane and diethyl ether. Crystallization from pentane at -27
°C afforded orange-red microcrystals: yield 0.43 g of 10 (14%);
mp (dec) > 135 °C. Crystallization from diethyl ether gave dark
brown cubes: yield 0.50 g of 14 (21%). 10: Anal. Calcd for
C39H42CoO3P3 (mol wt 710.6): C, 65.92; H, 5.96. Found:
C, 65.78; H 6.11. IR (Nujol mull, 2600-1500 cm-1): 1597 s,
ν(CdO); 1578 s, 1526 s, ν(CdC). 1H NMR (300 MHz, THF-d8,
297 K): cis/trans-10 ) 64/36. cis-10: δ(PCH3) 1.38 (d, 2J(PH)
2
(81.0 MHz, THF-d8, 213 K): cis-12: δ(PCH3) 17.7 (t′, J(PP)
2
2
) 62 Hz, 1 P), 22.8 (dd, J(PP) ) 62 Hz, J(PP) ) 220 Hz, 1
P); δ(PC6H5) 46.8 (dd, 2J(PP) ) 62 Hz, 2J(PP) ) 220 Hz, 1 P).
trans-12: δ(PCH3) 16.2 (d, 2J(PP) ) 74 Hz, 2 P); δ(PC6H5) 26.4
2
(t, J(PP) ) 74 Hz, 1 P).
Crystallographic data for 2: C31H40CoO3P3, Mr ) 612.5,
crystal dimensions 0.50 × 0.25 × 0.20 mm, monoclinic, space
group P21/c, a ) 16.976(1) Å, b ) 8.8627(5) Å, c ) 21.5392
(12) Å, â ) 107.154(1)°, V ) 3096.5(3) Å3, Z ) 4, dcalcd ) 1.314
g/cm3, µ ) 0.739 mm-1. Data collection and refinement
details: Bruker AXS SMART APEX, Mo KR (λ ) 0.71073 Å)
radiation, graphite monochromator, T ) 298(2) K. A total of
23 318 unique reflections with 4.0° e 2θ e 56.7° were collected,
from which 7666 were independend (Rint ) 0.07). Semiempiri-
cal absorption correction (from equivalents) was applied. The
structure was solved by direct methods18 and refined with full-
matrix least-squares18 on F2, 367 parameters. All non-
hydrogen atoms were refined anisotropically, and H atoms
were derived from ∆F maps and allowed to ride on their
2
) 10.0 Hz, 9 H), 0.94 (d, J(PH) ) 10.0 Hz, 9 H). trans-10:
2
4
δ(PCH3) 0.80 (t′, | J(PH) + J(PH)| ) 8.4 Hz, 18 H). Without
assignment: δ(CH) 6.39-8.28 (m). 31P NMR (81.0 MHz, THF-
d8, 296 K): cis-10: δ(PCH3) 20.5 (s(br), 2 P); δ(PC6H5) 47.0
(s(br), 1 P); trans-10: δ(PCH3) 14.9 (s(br), 2 P); δ(PC6H5) 24.3
(s(br), 1 P).
attached carbon atoms with Uiso ) 1.2Uiso(C) and 1.5Uiso
-
(methyl-C). Disordered C atoms C4 and C5 were treated with
a split model (C41/C51, C42/C52) with half-occupation each.
Refinement converged at R1 ) 0.048 (I > 2σ(I)), wR2 ) 0.134
(all data), max. (∆/σ) ) 0.001, S ) 1.01, min./max. height in
final ∆F map -0.39/0.91 e/Å3.
Synthesis of (2-Oxobenzoly)(2-diphenylphosphanylphe-
nolato)bis(trimethylphosphine)cobalt(III) (11). A sample
containing 1.09 g (2.67 mmol) of mer-hydrido(2-oxobenzoyl)-
tris(trimethylphosphine)cobalt(III) (8) and 0.74 g (2.67 mmol)
of (2-diphenylphosphanyl)phenol in 80 mL of THF after 18 h
at room temperature formed a red-brown solution from which
a red solid was deposited. The volatiles were removed in vacuo,
and the resulting solid was washed with pentane and extracted
with diethyl ether. Crystallization at -27 °C afforded orange
microcrystals: yield 0.25 g of 11 (15%); mp (dec) > 250 °C.
Anal. Calcd for C31H36CoO3P3 (mol wt 608.5): C, 61.19; H, 5.96.
Found: C, 61.09; H 6.04. IR (Nujol mull, 2600-1570 cm-1):
1605 s, ν(CdO); 1565 s, ν(CdC). 1H NMR (300 MHz, THF-d8,
300 K): cis/trans-11 ) 54/46. cis-11: δ(PCH3) 0.84 (d, 2J(PH)
) 10.0 Hz, 9 H), 1.10 (dd, 2J(PH) ) 10.0 Hz, 4J(PH) ) 1.3 Hz,
Crystallographic data (excluding structure factors) for the
structures reported in this paper have been deposited with the
Cambridge Crystallographic Data Center as supplementary
publication no. CCDC 252875. Copies of the data can be
obtained free of charge on application to CCDC, 12 Union
Road, Cambridge CB21EZ, UK (fax: (+44)1223-336-033;
e-mail: deposit@ccdc.cam.ac.uk).
Acknowledgment. Financial support of this work
by the Excellent Young Teachers Program of MOE
(P.R.C.) by the Scientific Research Foundation for the
Returned Overseas Chinese Scholars/State Education
Ministry, Natural Science Foundation of Shandong
University for Young Scientists and by Deutsche For-
schungsgemeinschaft is gratefully acknowledged.
2
9 H). trans-11: δ(PCH3) 0.52 (t′, | J(PH) + 4J(PH)| ) 8.9 Hz,
18 H); without assignment: δ(CH) 5.60-8.17 (m). 13C NMR
1
(75.4 MHz, THF-d8, 300 K): δ(PCH3) 12.0 (t′, | J(PC) + 3J(PC)|
) 26.4 Hz), 13.0 (d, 1J(PC) ) 25.2 Hz), 15.0 (d, 1J(PC) ) 27.7
Hz), δ(CH) 112.1, 112.4, 113.1, 118.5, 119.4, 126.4, 126.5,
128.3, 128.4, 128.6, 128.7, 129.9, 132.4, 132.7, 132.9, 133.3,
133.4, 133.5, 134.6, 136.0; δ(CO) 173.2, 178.2; δ(CCO) 203.4.
31P NMR (81.0 MHz, THF-d8, 213 K): cis-11: δ(PCH3) 22.0
(m, 2 P); δ(PC6H5) 47.5 (dd, 2J(PP) ) 220.0 Hz, 2J(PP) ) 57.8
Supporting Information Available: Tables containing
full X-ray crystallographic data for 2. This material is available
free of charge via the Internet at http://pubs.acs.org.
OM0489960
2
Hz, 1 P), trans-11: δ(PCH3) 16.2 (d, J(PP) ) 68.6 Hz, 2 P);
(18) SMART (version 5.62), SAINT (version 6.02), SADABS,
SHELXTL (version 6.10); Bruker AXS Inc.: Madison, WI, 2002.
δ(PC6H5) 26.3 (s(br), 1 P).