2-Diphenylphosphinobenzaldehyde as chelating ligand in trimethylphosphine complexes of cobalt and nickel

Article abstract of DOI:10.1021/om980462+

Methylnickel complexes activate the C(O)-H function of 2-diphenylphosphinobenzaldehyde to form five-membered chelate rings Ni(Ph₂P≡C=O) which occupy OC-axial and P-equatorial positions in the trigonal bipyramidal configuration of nickel(d⁸

Full text of DOI:10.1021/om980462+

4196
Organometallics 1998, 17, 4196-4201
2-Dip h en ylp h osp h in oben za ld eh yd e a s Ch ela tin g Liga n d
in Tr im eth ylp h osp h in e Com p lexes of Coba lt a n d Nick el
Hans-Friedrich Klein,* Ute Lemke, Mathias Lemke, and Alexandra Brand
Institute for Inorganic Chemistry, Darmstadt University of Technology, Petersenstrasse 18,
64287 Darmstadt, FRG
Received J une 5, 1998
Methylnickel complexes activate the C(O)-H function of 2-diphenylphosphinobenzaldehyde
to form five-membered chelate rings Ni(Ph2PkCdO) which occupy OC-axial and P-equatorial
positions in the trigonal bipyramidal configuration of nickel(d8) compounds Ni(Ph2PkCd
O)X(PMe3)2 (X ) Cl (1), Br (2), I (3), Me (4)). Methylcobalt complexes react with
2-diphenylphosphinobenzaldehyde to afford an isoelectronic species Co(Ph2PkCdO)(PMe3)3
(5) of similar configuration, while cobalt halides CoX(PMe3)3 oxidatively add the aldehyde
function to produce octahedral compounds mer-CoH(X)(Ph2PkCdO)(PMe3)2 (X ) Cl (6), Br
(7), I (8)). Carbon monoxide replaces an axial trimethylphosphine in 5, while iodomethane
gives rise to an oxidative substitution producing CoI(Ph2PkCdO)(PMe3)2 (10) (17 valence
electrons). The molecular structures of compounds 3, 5, 6, and 10 have been solved by X-ray
crystallography.
Sch em e 1. 18-Electr on Ch ela tes of Nick el(II) a n d
Coba lt(I),(III)
In tr od u ction
Chelating ligands containing hard/soft donor atoms
at a bite angle close to 90° can alter the reactivity of
metal centers by setting up trans and cis influences of
different strengths in perpendicular directions. For
example acylphenolato dianions -OkCO- when assisted
by trimethylphosphines (complex F in Scheme 1) can
polarize a nickel d8 center in such a way as to effect an
oxidative addition of iodoalkane,1 which is otherwise not
observed.
We set out to investigate the effect that a soft/soft
chelating ligand would exert on metal centers if com-
bined with trimethylphosphines.
An anionic chelating acyl ligand containing soft/soft
donor atoms can be derived from 2-diphenylphosphi-
nobenzaldehyde (A). Addition of the aldehyde C-H
function across platinum group metals has been ob-
served with Rh,2 Ir,3 Pd,4 and Pt5 complex centers, and
the expected five-membered metallocycles have been
established by X-ray crystallography. As no complexes
of 2-phosphinoacyl ligands with nickel or cobalt have
been reported, we chose as target molecules the perti-
nent nickel halide compounds D and the isoelectronic
cobalt(I) complex E, in order to compare their properties
with those of the corresponding 2-acylphenolato com-
pounds F 6 and G7 of the hard/soft type as derived from
salicylaldehyde (B) and with those of 2-phosphinophe-
nolato chelates H8 and I9 of the soft/hard type as derived
from phosphinophenols (C).
(1) Klein, H.-F.; Bickelhaupt, A.; J ung, T.; Cordier, G. Organome-
tallics 1994, 13, 2557-2559.
(2) (a) Ko, J .; J oo, W. C.; Kong, Y. K. Bull. Korean Chem. Soc. 1986,
7, 338-341. (b) Ko, J .; J oo, W. C.; Bull. Korean Chem. Soc. 1987, 8,
372-376.
Resu lts a n d Discu ssion
(3) Landvatter, E. B.; Rauchfuss, T. B.Organometallics 1982, 1,
506-513.
Methyl(trimethylphosphine)nickel halide complexes
in a sluggish reaction according to eq 1, which is slowest
(4) (a) Gao, J .; Wang, Y.; Lin, Z.; Wan, H. Tianranqi Huagong 1994,
19, 6-10. (b) Gao, J .-X.; Wang, J .-Z.; Hu, S.-Z.; Wan, H.-L. Gaodeng
Xuexiao Huaxue Xuebao 1995, 16, 666-669.
(7) Klein, H.-F.; Haller, S.; Sun, H.; Li, X.; J ung, T.; Ro¨hr, C.;
Floerke, U.; Haupt, H.-J . Z. Naturforsch., in press.
(8) Dal, A. Thesis, Greifswald University, 1998.
(9) Klein, H.-F., Brand, A.; Cordier, G. Z. Naturforsch. 1998, 53b,
307.
(5) Ghilardi, C. A.; Midollini, S.; Moneti, S.; Orlandini, A. J . Chem.
Soc., Dalton Trans. 1988, 1833-1836.
(6) Klein, H.-F.; Bickelhaupt, A.; Hammerschmitt, B.; Floerke, U.;
Haupt, H.-J . Organometallics 1994, 13, 2944-2950.
S0276-7333(98)00462-2 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 08/25/1998

Chelating Diphenylphospinoacyl Ligands
Organometallics, Vol. 17, No. 19, 1998 4197
for chloride, are converted by 2-diphenylphosphino-
benzaldehyde to afford the new nickel chelates 1-3 in
good to excellent yields. Added trimethylphosphine
effectively blocks the reaction (eq 1) but does not
interfere in the formation of the methylnickel compound
4 acccording to eq 2.
F igu r e 1. Molecular structure of 3; selected distances (Å)
and angles (deg): Ni1-I1 2.6633(6), Ni1-C1 1.892(4), Ni1-
P1 2.2282(11), Ni1-P2 2.2400(13), Ni1-P3 2.2517(12),
O1-C1 1.212(5), C1-C2 1.510(6), P1-C7 1.823(4), P1-C8
1.830(4), P1-C14 1.829(4); C1-Ni1-P2 89.70(14), C1-
Ni1-P3 86.93(14), C1-Ni1-P1 88.15(13), C2-C1-Ni1
118.1(3), C7-C2-C1 119.9(4), C2-C7-P1 112.9(3), C7-
P1-Ni1 100.79(13), C1-Ni1-I1 177.98(13), P1-Ni1-P2
126.54(5), P2-Ni1-P3 123.39(5), P1-Ni1-P3 109.81(4),
P1-Ni1-I1 93.87(3), P2-Ni1-I1 89.00(4), P3-Ni1-I1
92.50(3), O1-C1-C2 118.5(4), O1-C1-Ni1 123.4(3).
Only the generation of 1 is accompanied by P-C bond
cleavage and formation of trans-NiCl(Ph)(PMe3)2.10 The
remainders of the 2-phosphinoacyl ligand have not been
detected among the products.
Complexes 1-4 form dark-red/violet or bright red (4)
crystals which are soluble in ether or pentane, as
expected for coordinatively saturated molecular species.
31P NMR resonances show a pattern of couplings that
are in accord with angles PNiP close to 120° and a
D-type configuration. A marked low-field shift of the
carbonyl 13C signal is caused by the strong trans
influence of the NiX group, which decreases in the order
X ) Me > I > Br > Cl.
In an attempted decarbonylation reaction, which is
typical for nonchelating acylnickel compounds,11 1 was
found to be unreactive toward Ni(PMe3)4. There was
no indication of ligand dissociation, and the air stability
is good.
The molecular structure of 3 is shown in Figure 1.
The nickel atom is centered in a trigonal bipyramid of
donor atoms attaining an unusual pentacoordination.
The 18-valence electron count is at variance with the
usual square planar geometry of acylnickel halides.12
The most likely explanation for the stable pentacoordi-
nation is based on a steric argument. In a supposed
square planar arrangement of ligand functions the acyl
group would be forced into the plane of the chelate ring,
thereby causing repulsion with an in-plane trimeth-
ylphosphine group at an angle C(O)-Ni-P of about 90°.
A freely rotating acyl group would be oriented in a
direction perpendicular to the plane of coordination.12
The three equatorial phosphine-donor groups are ori-
ented for optimum p interactions. To arrive at the
F igu r e 2. Molecular structure of 5; selected distances (Å)
and angles (deg): Co1-C1 1.950(3), Co1-P1 2.1588(7),
Co1-P2 2.2215(8), Co1-P3 2.1898(9), Co1-P4 2.2238(8),
O1-C1 1.230(3), C1-C2 1.523(4), C7-P1 1.828(3), P1-C14
1.862(3); C1-Co1-P2 179.01(9), C1-Co1-P1 85.56(8),
C1-Co1-P3 82.39(8), C1-Co1-P4 84.88(8), P1-Co1-P2
94.61(3), P1-Co1-P3 117.54(3), P1-Co1-P4 122.14(3),
Co1-C1-C2 118.4(2), C1-C2-C7 118.2(2), C2-C7-P1
111.1(2), C7-P1-Co1 103.85(9), O1-C1-C2 115.5(2), O1-
C1-Co1 126.0(2).
molecular structure of the cobalt(II) analogue 10 (17
valence electrons, Figure 4), considerable distortion of
ligand positions is required.
The corresponding 18-electron cobalt(I) complex 5 is
smoothly formed by an aldehyde reaction with a suitable
methylcobalt(I) or trimethylcobalt(III) complex accord-
ing to eq 3.
(10) (a) Klein, H.-F., Reitzel, L. Chem. Ber. 1988, 121, 1115-1118.
(b) Carmona, E.; Paneque, M.; Poveda, M. L. Polyhedron 1989, 8, 285-
291.
(11) Klein, H.-F., Karsch, H. H. Chem. Ber. 1976, 109, 2524-2532.
(12) (a) Huttner, G.; Orama, O.; Bejenke, V. Chem. Ber. 1976, 109,
2533-2536. (b) Ca´mpora, J .; Gutie´rrez, E.; Monge, A.; Poveda, M. L.;
Carmona, E. Organometallics 1992, 11, 2644-2649.

4198 Organometallics, Vol. 17, No. 19, 1998
Klein et al.
F igu r e 3. Molecular structure of 6; selected distances (Å)
and angles (deg): Co1-Cl1 2.4061(11), Co1-P1 2.1750(10),
Co1-P2 2.2230(11), Co1-P3 2.2549(12), Co1-C1 1.891-
(4), P1-C7 1.818(3), P1-C8 1.826(4), P1-C14 1.833(3),
C2-C7 1.392(5), C1-C2 1.521(5); C1-Co1-P2 92.42(12),
C1-Co1-P1 88.01(11), C1-Co1-P3 87.30(12), C1-Co1-
Cl1 176.08(12), P1-Co1-P2 147.29(5), P1-Co1-P3 103.96-
(4), P1-Co1-Cl1 88.23(4), Co1-C1-C2 118.3(2), C1-C2-
C7 118.2(3), C2-C7-P1 112.7(3), C7-P1-Co1 101.91(11),
C7-P1-C14 105.5(2), C8-P1-C14 104.1(2), C7-P1-C8
102.8(2).
F igu r e 4. Molecular structure of 10; selected distances
(Å) and angles (deg): Co1-I1 2.6629(12), Co1-P1 2.2149-
(12), Co1-P2 2.2402(14), Co1-P3 2.2409(14), Co1-C1
1.878(4), P1-C7 1.828(4), P1-C14 1.839(4), C2-C7 1.381-
(6), C1-C2 1.508(6); C1-Co1-P2 87.26(13), C1-Co1-P1
88.58(14), C1-Co1-P3 86.20(13), C1-Co1-I1 167.32(14),
P1-Co1-P2 102.33(5), P1-Co1-P3 103.81(5), P1-Co1-
I1 104.09(4), Co1-C1-C2 118.5(3), C1-C2-C7 119.1(3),
C2-C7-P1 113.5(3), C7-P1-Co1 100.16(14), C7-P1-C14
105.0(2), C8-P1-C14 107.2(2), C7-P1-C8 105.3(2).
if the large angle P1-Co-P2 ) 147.29(5)° is taken to
indicate where the hydride ligand resides. The CoH
function has not been fully located in the molecular
structure but is strongly supported by spectroscopy. The
Co-C bond in 6 is 6 pm shorter and the chelate bite
angle (æ ) 88.01(11)°) is 3° larger than in 5, while other
values remain in the expected range.
As an electron-rich compound of cobalt(I), 5 is ex-
pected to react with p-acceptor ligands. We have not
succeeded in reacting ethene with 5 under conditions
that proved suitable for 2-phosphanylphenolato com-
plexes (I in Scheme 1).9 However, carbon monoxide
according to eq 5 substitutes one of the trimethylphos-
phines, selectively occupying the ligand position op-
posite the acyl group as shown by 31P doublet (2P) and
doublet of doublets (1P) resonances. The ν(CO) value
observed in this case, 1920 cm-1, approaches that in a
corresponding 2-phosphanylphenolato carbonyl com-
Using cobalt(I) halides in a synthesis according to eq
4, the aldehyde reaction proceeds to air-stable cobalt-
(III) species 6-8, which do not spontaneously eliminate
HX to form 5 and are inert toward triethylamine at 20
°C. Complex 5 forms dark brown crystals, 6 forms dark
olive crystals, while 7 and 8 are obtained as yellow and
orange microcrystals, respectively. Infrared spectra of
compounds 6-8 contain medium-intensity bands at
1923-1929 cm-1 which are assigned to CoH stretching
vibrations, and each correspond with a high-field CoH
proton multiplet resonance. Other NMR data are
compatible with a low-spin state and octahedral coor-
dination of cobalt(d6).
plex9 (type I in Scheme 1), where ν(CO) ) 1900 cm-1
.
Both values indicate tight Co-CO bonding in an apical
position, which is unusual for pentacoordinate d8 com-
plexes.13
While 5 does not react with bromomethane or dibro-
moethane, oxidative addition of iodomethane according
to eq 6 yields an odd-electron oxidation product (d7)
instead of transforming 5 into an octahedral cobalt (d6)
complex. Complex 10 is obtained as black crystals with
an elemental composition that makes it a 17-electron
homologue of 3.
The molecular structure of 5 is shown in Figure 2.
The cobalt atom resides in the center of a trigonal
bipyramidal arrangement of one carbon and four phos-
phorus donor atoms with an axial acyl group (type E in
Scheme 1). The bite-angle æ of the chelating 2-phos-
phinobenzoyl ligand C1-Co-P1 ) 85.56(8)° is equal
within experimental error to those of the phosphinophe-
nolato monoanionic (æ ) 85.65(4)°)9 or the acylphenolato
dianionic (æ ) 85.5(2)°) ligands.7
It was therefore of interest to compare the two
molecular structures. No attempt has been made at
drawing a molecule 10 (Figure 4) in a way that would
In Figure 3 the molecular structure of 6 is consistent
(13) Mcgregor, S. A.; Lu, Z.; Eisenstein, O.; Crabtree, R. H. Inorg.
Chem. 1994, 33, 3616-3618.
with a mer-octahedral coordination of a cobalt(d6) center

Chelating Diphenylphospinoacyl Ligands
Organometallics, Vol. 17, No. 19, 1998 4199
published procedures. Other chemicals (Aldrich) were used
as purchased.
P r ep a r a tion of tr a n s-(2-Dip h en ylp h osp h in o)ben zoyl-
ch lor obis(tr im eth ylp h osp h in e)n ick el (1). trans-NiCl(Me)-
(PMe3)2 (0.56 g, 2.14 mmol) and 2-diphenylphosphinobenzal-
dehyde (0.62 g, 2.14 mmol) in 70 mL of THF were allowed to
react at 20 °C. After 18 h the volatiles were removed from a
dark red mixture in vacuo, and the red solid was extracted
with ether over a glass-sinter disk (G3). From a volume of 60
mL at -25 °C dark red microcrystals (0.66 g, 57%) and large
orange needles of trans-NiCl(Ph)(PMe3)210 (0.39 g, 1.21 mmol)
as a byproduct were isolated and mechanically separated
(identified by NMR), mp 95-102 °C (dec). Anal. Calcd for
C25H32ClNiOP3 (535.6): C, 56.06; H, 6.02; P, 17.35. Found:
C, 56.01; H, 6.01; P, 16.72. IR (Nujol solution, 4000-1600
cm-1): 3043 (w) ν(CC-H), 1614 (vs) ν(CO). 1H NMR (300
MHz, THF-d8, 25 °C): δ(PCH3) 1.08 (s, 18 H), δ(CH) 7.5 (m,
14 H). 13C NMR (75.4 MHz, THF-d8, 25 °C): δ(PCH3) 13.7,
δ(CC) 120-151, δ(OC) 230.0. 31P NMR (81 MHz, THF-d8, 25
°C): δ(PCH3) -13.5 (d, 2 P, 2J (PP) ) 176 Hz), δ(PCC) 38.1 (dd,
match the picture of 3 (Figure 1), as both structures
have little in common. The molecules 10 and 3 adopt
the same configuration, while bond lengths around the
two metals are of the expected order and show a
pairwise correspondence. However, angles and coordi-
nation geometries of 10 and 3 and the packings are more
different than accounted for by substituting a d7 for a
d8 metal center. The observed structural diversity
merits further investigation.
2
1 P, J (PP) ) 176 and 180 Hz).
P r ep a r a tion of tr a n s-(2-Dip h en ylp h osp h in o)ben zoyl-
br om obis(tr im eth ylph osph in e)n ickel (2). trans-NiBr(Me)-
(PMe3)2 (0.80 g, 2.62 mmol) and 2-diphenylphosphinobenzal-
dehyde (0.76 g, 2.66 mmol) in 60 mL of THF were kept at 20
°C for 6 h. The dark red solution was evaporated to dryness
and the residue crystallized from ether to afford as the only
product dark red crystals (0.62 g, 40%), mp 144-147 °C (dec).
Anal. Calcd for C25H32BrNiOP3 (580.0): C, 51.77; H, 5.56; P,
16.02. Found: C, 51.80; H, 5.56; P, 16.12. IR (Nujol solution,
4000-1600 cm-1): 3042 (w) ν(CC-H), 1614 (vs) ν(CO). 1H
NMR (300 MHz, THF-d8, 25 °C): δ(PCH3) 1.17 (t′, 18 H,
Con clu sion
Combining nickel and cobalt with anionic phenolate
as hard oxygen donor and anionic acyl or neutral
diarylphosphino groups as soft C or P donor functions
in 1,2 positions of an aromatic ring (as derived from A,
B, and C in Scheme 1) gives five-membered chelate
rings of closely related geometries. Bidentate bite
angles range from 85° to 88°. Ring-opening reactions
and tetrahedral coordination of metals are not observed.
In trigonal bipyramidal or octahedral complexes regio-
selective dissociation of monodentate co-ligands and
substitution reactions are controlled by the whole set
of donor functions and modified by the anisotropy of
metal centers which is imposed by the different trans
influences. Starting from CoBr(PMe3)3 and C, the
chelate ring is incorporated in a pentacoordinate cobalt-
(I) complex by amine-assisted elimination of HBr.9 CoCl-
(PMe3)3 oxidatively adds A to give exclusively mer-6,
which does not eliminate HCl toward triethylamine.
Only the soft/soft chelate ligand derived from A appears
to favor oxidation of cobalt (d8 f d6) but is not observed
to form an isoelectronic hydridonickel(d6) intermediate
in the generation of 1-4. Trimethylphosphine ligands
in 4 are tightly coordinated, as shown by extensive
coupling of 31P nuclei. Formally replacing the soft acyl
function by a hard phenolate ligand preserves the
configuration (of D and H in Scheme 1) but induces fast
dissociation of trimethylphosphines in solution and loss
of 1 equiv in vacuo at 20 °C to reversibly form a square
planar methylnickel complex.8
2
4
| J (PH) + J (PH)| ) 6.9 Hz), δ(CH) 7.5 (m, 14 H). 13C NMR
(75.4 MHz, THF-d8, 25 °C): δ(PCH3) 14.5, δ(CC) 120-151,
δ(OC) 233.7. 31P NMR (81 MHz, THF-d8, 25 °C): δ(PCH3)
2
2
-16.6 (d, 2 P, J (PP) ) 172 Hz), δ(PCC) 39.8 (dd, 1 P, J (PP)
) 172 and 170 Hz).
P r ep a r a tion of tr a n s-(2-Dip h en ylp h osp h in o)ben zoyl-
iod obis(tr im eth ylp h osp h in e)n ick el (3). From trans-NiI-
(Me)(PMe3)2 (0.50 g, 1.42 mmol) and 2-diphenylphosphino-
benzaldehyde (0.42 g, 1.45 mmol) in 70 mL of THF in a similar
procedure dark violet crystals (0.77 g, 86%) were obtained, mp
197-198 °C (dec). Anal. Calcd for C25H32INiOP3 (627.1): C,
47.89; H, 5.14. Found: C, 47.71; H, 5.14. IR (Nujol solution,
4000-1600 cm-1): 3043 (w) ν(CC-H), 1613 (vs) ν(CO). 1H
NMR (300 MHz, THF-d8, 25 °C): δ(PCH3) 1.24 (s, 18 H), δ(CH)
7.5 (m, 14 H). 13C NMR (75.4 MHz, THF-d8, 25 °C): δ(PCH3)
16.1, δ(CC) 121-151, δ(OC) 237.0. 31P NMR (81 MHz, THF-
2
d8, 25 °C): δ(PCH3) -18.9 (d, 2 P, J (PP) ) 171 Hz), δ(PCC)
2
43.7 (dd, 1 P, J (PP) ) 171 and 169 Hz).
P r ep a r a tion of tr a n s-(2-Dip h en ylp h osp h in o)ben zoyl-
m eth ylbis(tr im eth ylp h osp h in e)n ick el (4). trans-NiMe2-
(PMe3)3 (0.92 g, 2.90 mmol) and 2-diphenylphosphinobenzal-
dehyde (0.84 g, 2.66 mmol) were combined in 70 mL of THF
at -70 °C. During warmup the orange mixture slowly turned
dark red, and after 5 h at 20 °C the volatiles were removed in
vacuo. Crystallization from pentane at -25 °C gave bunches
of red needles (0.24 g, 16%), mp 48-52 °C (dec). Anal. Calcd
for C26H32NiOP3 (515.2): C, 60.62; H, 6.85; P, 18.04. Found:
C, 59.68; H, 6.83; P, 18.44. IR (Nujol solution, 4000-1580
cm-1): 3049 (w) ν(CC-H), 1588 (vs) ν(CO). 1H NMR (300
3
MHz, THF-d8, 25 °C): δ(NiCH3) -0.79 (q, 3 H, J (PH) ) 11.8
Hz), δ(PCH3) 0.97 (s, 18 H), δ(CH) 7.4 (m, 14 H). 13C NMR
2
(75.4 MHz, THF-d8, 25 °C): δ(NiCH3) -14.9 (q, J (PC) ) 18.3
Exp er im en ta l Section
Hz), δ(PCH3) 16.6, δ(CC) 120-158, δ(OC) 266.6. 31P NMR (81
MHz, THF-d8): δ(PCH3) -8.4 (d, 2 P, 2J (PP) ) 175 Hz), δ(PCC)
Gen er a l P r oced u r es a n d Ma ter ia ls. Standard vacuum
techniques were used in manipulations of volatile and air-
sensitive material. Details of characterization and spectro-
scopic instrumentation have been given elsewhere.6
2
52.6 (dd, 1 P, J (PP) ) 169 and 175 Hz).
(14) Rauchfuss, T. B.; Hoots, J . E. Inorg. Synth. 1982, 21, 175-179.
(15) Klein, H.-F.; Karsch, H. H. Chem. Ber. 1975, 108, 944-955.
(16) Klein, H.-F.; Karsch, H. H. Inorg. Chem. 1974, 14, 473-478.
(17) Klein, H.-F.; Karsch, H. H. Chem. Ber. 1973, 106, 1433-1452.
2-Diphenylphosphinobenzaldehyde,14 methylcobalt,15 CoX-
(PMe3)3,16 and methylnickel complexes17 were prepared by

4200 Organometallics, Vol. 17, No. 19, 1998
Klein et al.
Ta ble 1. Cr ysta l Da ta a n d Refin em en t Deta ils for
3 a n d 6
P r ep a r a t ion of (2-Dip h en ylp h osp h in o)b en zoylt r is-
(tr im eth ylp h osp h in e)coba lt (5). CoMe(PMe3)4 (0.92 g, 2.43
mmol) and 2-diphenylphosphinobenzaldehyde (0.68 g, 2.34
mmol) in 60 mL of ether were allowed to react at 20 °C until
evolution of gas ceased. After 2 h the orange-brown solution
was filtered, reduced to a volume of 20 mL in vacuo, and kept
at -25 °C. Black crystals (0.36 g) were isolated by decantation
and drying in vacuo. From the mother liquor (10 mL) a second
crop was obtained (combined yields 0.58 g, 43%), mp 129-
131 °C. Anal. Calcd for C28H41CoOP4 (576.4): C, 58.34; H,
7.12; P, 21.49. Found: C, 58.19; H, 7.04; P, 20.78. IR (Nujol
solution, 4000-1500 cm-1): 1583 (m), 1533 (vs) ν(CO). 1H
NMR (300 MHz, THF-d8, 25 °C): δ(PCH3) 0.95 (d, 9 H, 2J (PH)
3
5
formula
fw
C
627.1
25H32NiIOP3
C28H41CoOP4
576.4
cryst size, mm
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
0.64 × 0.21 × 0.36 0.19 × 0.34 × 0.31
monoclinic
P21/n
triclinic
P1h
8.6929(12)
20.050(2)
15.7078(11)
90
92.704(13)
90
9.3472(6)
10.7934(7)
15.3066(14)
104.127(8)
91.399(7)
102.123(11)
1459.5(2)
2
2
) 5.4 Hz), δ(PCH3) 1.23 (t′, 18 H, | J (PH) + 4J (PH)| ) 9.0 Hz),
2734.7(5)
4
δ(CH) 7.4 (m, 14 H). 13C NMR (75.4 MHz, THF-d8, 25 °C):
δ(PCH3) 21.3 (m), δ(CC) 117.7 (d, J (PC) ) 18.3 Hz), 126.3 (d,
J (PC) ) 7.6 Hz), 127.0 (m), 127.3 (d, J (PC) ) 2.7 Hz), 127.6
(d, J (PC) ) 9.2 Hz), 132.4 (d, J (PC) ) 13.7 Hz), 140.8 (m),
δ(OC) 254.7. 31P NMR (81 MHz, THF-d8, 233 K): δ(PCH3) 1.1
Z
D
calc, g/cm3
1.523
1.312
µ(Mo KR), mm-1
temp, K
2.029
0.826
293(2)
293(2)
data coll range, deg
limiting indices
2.03 e θ e 24.99
-10 < h < 1,
-23 < k < 1,
-18 < l < 18
2 e θ e 30
-13 < h < 1,
-14 < k < 14,
-21 < l < 21
9866
2
2
(dd, 2 P, J (PP) ) 82 and 45 Hz), δ(PCH3) 16.2 (q, 1 P, J (PP)
2
) 45 Hz), δ(PCC) 70.0 (dt, 1 P, J (PP) ) 82 and 45 Hz).
P r ep a r a tion of m er -Ch lor o(h yd r id o)(2-d ip h en ylp h os-
p h in o)ben zoylbis(tr im eth yl-p h osp h in e)coba lt (6). CoCl-
(PMe3)3 (0.90 g, 2.79 mmol) and 2-diphenylphosphinobenzal-
dehyde (0.72 g, 2.48 mmol) in 60 mL of THF were allowed to
react at 20 °C. After 2 h the mixture was filtered, and an olive
green solid was obtained, which was washed with ether. The
raw product (1.30 g) was recrystallized from THF to afford
dark green crystals (0.420 g, 32%), mp 109-111 °C (dec). Anal.
Calcd for C25H33ClCoOP3 (536.9): C, 55.93; H, 6.20; P, 17.31.
Found: C, 55.68; H, 6.13; P, 17.05. IR (Nujol mull, 4000-
1500 cm-1): 1923 (m) ν(CoH), 1603 (s) ν(CO). 1H NMR (300
MHz, THF-d8, 25 °C): δ(CoH) -10.5 (m, 1 H), δ(PCH3) 0.87
(s, 9 H), δ(PCH3) 1.56 (s, 9 H), δ(CH) 7.2 (m, 14 H). 13C NMR
(75.4 MHz, THF-d8, 25 °C): δ(PCH3) 15.9 (d, 1J (PC) ) 22.6 Hz),
no. of reflns measured 6198
no. of unique data
parameters
4812 (Rint ) 0.0353) 8469 (Rint ) 0.0258)
282
309
goodness of fit on F2
R1 (I > 2σ(I))
1.053
0.0412
0.0506
0.1113
1.036
0.0479
0.0729
0.1467
R1 (all data)
wR2 (all data)a
a
w ) 1/σ2(F) + 0.0001F2.
Ta ble 2. Cr ysta l Da ta a n d Refin em en t Deta ils for
6 a n d 10
6
10
formula
fw
C
536.8
25H33ClCoOP3
C25H32CoIOP3
627.3
1
δ(PCH3) 19.3 (d, J (PC) ) 26.6 Hz), δ(CC) 121.1 (d, J (PC) )
cryst size, mm
cryst syst
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
0.45 × 0.30 × 0.14 0.50 × 0.60 × 0.53
15.7 Hz), 129.0 (d, J (PC) ) 10.3 Hz), 130.6 (d, J (PC) ) 8.5
Hz), 131.2 (m), 133.4 (d, J (PC) ) 8.6 Hz), 136.0 (d, J (PC) )
10.2 Hz), 139.6 (m), 152.6 (m), δ(OC) 248.6. 31P NMR (81 MHz,
THF-d8, 233 K): δ(PCH3) 5.9 (m, 1 P), δ(PCH3) 15.8 (d, 1 P,
monoclinic
P21/n
monoclinic
P21/c
8.5689(14)
20.057(3)
15.312(2)
90
9.045(3)
33.347(7)
9.150(3)
90
2
2J (PP) ) 232 Hz), δ(PCC) 75.7 (d, 1 P, J (PP) ) 227 Hz). MS
(FD, 0-5 mA; m/e (35Cl) (%)): 536(100), M; 460(13), M - PMe3.
P r ep a r a tion of m er -Br om o(h yd r id o)(2-d ip h en ylp h os-
p h in o)ben zoylbis(tr im eth ylp h osp h in e)coba lt (7). CoBr-
(PMe3)3 (0.52 g, 1.42 mmol) and 2-diphenylphosphinobenzal-
dehyde (0.52 g, 1.42 mmol) in 60 mL of THF were allowed to
react at 20 °C. After 4 h an orange-brown solution was
obtained, from which a slight turbidity was removed by
filtering over a glass-sinter disk (G3). The volatiles were
removed in vacuo to yield 0.77 g of a yellow powder (93% raw
yield). Crystallization from THF afforded yellow microcrystals
94.714(14)
90
98.83(4)
90
2622.6(7)
4
2726.9(14)
4
Z
D
calc, g/cm3
1.360
1.528
µ(Mo KR), mm-1
temp, K
0.955
1.952
293(2)
293(2)
data coll range, deg
limiting indices
2.03 e θ e 25.00
-10 < h < 1,
-23 < k < 23,
-18 < l < 18
2.28 e θ e 30.96
-10 < h < 1,
-1 < k < 39,
-10 < l < 10
6916
(0.32 g, 39%), mp 143-145 °C (dec). Anal. Calcd for C25H33
-
no. of reflns measured 11 020
BrCoOP3 (536.9): C, 51.66; H, 5.72; P, 15.98. Found: C, 51.78;
H, 5.68; P, 15.84. IR (Nujol mull, 4000-1500 cm-1): 1923 (m)
ν(CoH), 1605 (s) ν(CO). 1H NMR (300 MHz, THF-d8, 25 °C):
δ(CoH) -10.8 (m, 1 H), δ(PCH3) 0.91 (d, 9 H, 2J (PH) ) 5.7
no. of unique data
parameters
4620 (Rint ) 0.0376) 4788 (Rint ) 0.0330)
280
280
goodness of fit on F2
R1 (I > 2σ(I))
1.036
0.0481
0.0667
0.1340
1.066
0.0359
0.0483
0.0969
2
Hz), δ(PCH3) 1.90 (d, 9 H, J (PH) ) 7.5 Hz), δ(CH) 7.7 (m, 14
R1 (all data)
wR2 (all data)a
H). 13C NMR (75.4 MHz, THF-d8, 25 °C): δ(PCH3) 14.8 (d,
1
1J (PC) ) 22.9 Hz), δ(PCH3) 18.4 (d, J (PC) ) 27.5 Hz), δ(CC)
a
w ) 1/σ2(F) + 0.0001F2.
119.4 (d, J (PC) ) 15.3 Hz), 126.5 (d, J (PC) ) 10.7 Hz), 127.1
(d, J (PC) ) 9.2 Hz), 129.0 (m), 129.5 (d, J (PC) ) 4.6 Hz), 129.7,
131.7 (d, J (PC) ) 9.2 Hz), 134.1 (d, J (PC) ) 10.7 Hz). 31P NMR
(81 MHz, THF-d8, 233 K): δ(PCH3) 3.1 (m, 1 P), δ(PCH3) 13.4
disk (G3). The volatiles were removed in vacuo to yield 0.81
g of an orange solid (88% raw yield). Crystallization from THF
afforded orange-red crystals (0.39 g, 42%), mp 146-148 °C.
Anal. Calcd for C25H33CoIOP3 (628.3): C, 47.79; H, 5.29; P,
14.79. Found: C, 47.66; H, 5.16; P, 14.77. IR (Nujol mull,
4000-1500 cm-1): 1929 (m) ν(CoH), 1604 (s) ν(CO). 1H NMR
(300 MHz, THF-d8, 25 °C): δ(CoH) -11.7 (m, 1 H), δ(PCH3)
0.94 (s, 9 H), δ(PCH3) 0.98 (s, 9 H), δ(CH) 7.7 (m, 14 H). 13C
NMR (75.4 MHz, THF-d8, 25 °C): δ(PCH3) 16.2 (d, 1J (PC) )
2
(dd, 1 P, J (PP) ) 225 and 36 Hz), δ(PCC) 76.5 (m, 1 P). MS
(FD, 0-15 mA; m/e (81Br) (%)): 583(100), M.
P r ep a r a tion of m er -Iod o(h yd r id o)(2-d ip h en ylp h osp h i-
n o)ben zoylbis(tr im eth ylph osph in e)cobalt (8). CoI(PMe3)3
(0.61 g, 1.47 mmol) and 2-diphenylphosphinobenzaldehyde
(0.44 g, 1.52 mmol) in 70 mL of THF were allowed to react at
20 °C. After 1 h a yellow solution was obtained, from which
a slight turbidity was removed by filtering over a glass-sinter
1
24.1 Hz), δ(PCH3) 20.4 (d, J (PC) ) 28.2 Hz), δ(CC) 119.2 (d,
J (PC) ) 15.6 Hz), 127.1 (m), 129.0 (d, J (PC) ) 22.9 Hz), 129.8,

Chelating Diphenylphospinoacyl Ligands
Organometallics, Vol. 17, No. 19, 1998 4201
132.1 (d, J (PC) ) 8.2 Hz), 133.9 (d, J (PC) ) 10.0 Hz). 31P NMR
(81 MHz, THF-d8, 223 K): δ(PCH3) -1.6 (m, 1 P), δ(PCH3) 8.4
(d, 1 P, J (PP) ) 182 Hz), δ(PCC) 78.1 (d, 1 P, J (PP) ) 216
Hz). MS (FD, 0-5 mA; m/e (%)): 629(50), M; 553(19), M -
PMe3.
black cubes (0.37 g, 41%), mp 181-183 (dec). Anal. Calcd for
C25H33CoIOP3 (627.3): C, 47.87; H, 5.14; P, 14.81. Found: C,
47.63; H, 5.12; P, 15.11. IR (Nujol mull, 4000-1500 cm-1):
1592 (s), 1565 (s), 1559 (s) ν(CO).
Cr ysta l Str u ctu r e Deter m in a tion s. Crystal data for 3,
5, 6, and 10 are given in Tables 1 and 2. Data collection and
refinement details: Siemens P4 diffractometer, Mo KR (λ )
0.71073 Å) radiation, graphite monochromator. An empirical
absorption correction via ψ-scans was applied in each case.
The structures were solved by direct methods17 and refined
by Fourier methods.18 All non-hydrogen atoms were refined
anisotropically; hydrogen atoms were held in idealized posi-
tions.
2
2
Rea ction of 5 w ith Ca r bon Mon oxid e. A 0.31 g (0.53
mmol) sample of 5 in 50 mL of ether was kept stirring under
1 bar CO for 15 h at 20 °C. The volatiles were removed in
vacuo, and the dark residue was recrystallized from pentane
to afford black cubes (0.12 g, 41%), mp 143-145 °C (dec). Anal.
Calcd for C26H32CoO2P3 (528.4): C, 59.10; H, 6.10; P, 17.58.
Found: C, 58.99; H, 6.10; P, 19.06. IR (Nujol mull, 4000-
1560 cm-1): 1920 (vs) ν(C°O), 1583 (s) ν(CdO). 1H NMR (300
2
MHz, THF-d8, 25 °C): δ(PCH3) 1.12 (t′, 18 H, | J (PH) + 4J (PH)|
) 7.3 Hz), δ(CH) 7.4 (m, 14 H). 13C NMR (75.4 MHz, THF-d8,
Ack n ow led gm en t . Support of this work by
Deutsche Forschungsgemeinschaft and Fonds der
Chemischen Industrie is gratefully acknowledged.
1
3
25 °C): δ(PCH3) 18.3 (t′, | J (PC) + J (PC)| ) 13.7 Hz), δ(CC)
119.4 (d, J (PC) ) 19.8 Hz), 127.0 (d, J (PC) ) 9.2 Hz), 127.6,
128.5 (m), 128.9, 129.1, 130.0 (d, J (PC) ) 12.2 Hz), 138.7 (m),
139.2 (m), 141.3 (d, J (PC) ) 30.5 Hz), 150.5 (d, J (PC) ) 62.6
Hz), δ(CtO) 220.6 (m), δ(CdO) 260.9 (m). 31P NMR (81 MHz,
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates, bond lengths and angles, and thermal parameters
(20 pages). Ordering information is given on any current
masthead page.
2
THF-d8, 223 K): δ(PCH3) 9.0 (d, 2 P, J (PP) ) 80 Hz), δ(PCC)
2
83.0 (t, 1 P, J (PP) ) 80 Hz).
Rea ction of 5 w ith Iod om eth a n e. An ether solution (70
mL) containing iodomethane (0.40 g, 2.78 mmol) was con-
densed onto 5 (0.82 g, 11.42 mmol) at -70 °C. The brown
mixture was kept at 20 °C for 15 h. An amber solid of
tetramethylphosphonium chloride (IR) was removed by filtra-
tion, and the red-violet solution was kept at -25 °C to yield
OM980462+
(18) Sheldrick, G. M. Acta Crystallogr. 1990, A46, 467.
(19) For 3 and 5: Sheldrick, G. M. SHELXL-86, University of
Goettingen, 1993. For 6 and 10: ibid., 1997.