Complexes of distibinomethane ligands. 1. Iron, cobalt, nickel, and manganese carbonyl complexes

Article abstract of DOI:10.1021/om9706121

The reaction of Fe₂(CO)₉ in thf with Ph₂SbCH₂SbPh₂ (dpsm) or Me₂SbCH₂SbMe₂ (dmsm) produced [Fe(CO)₄(η¹-dpsm)] and [Fe(CO)₄(μ-dmsm)Fe(CO)₄], and Co₂(CO)₈ reacted with either distibine ligand (L-L) to give [Co₂(CO)₄(μ-CO)₂(μ-L-L)]. Ni(CO)₄ and dpsm gave [Ni-(CO)₃(η¹-dpsm)] and [Ni(CO)₃(μ-dpsm)Ni(CO)₃], while with dmsm only [Ni(CO)₃(μ-dmsm)-Ni(CO)₃] was isolated. Mn₂(CO)₁₀ reacted slowly with dpsm or dmsm in the presence of a [{(Cp)Fe(CO)₂}₂] catalyst to give [Mn₂(CO)₈(L-L)], but no reaction occurred with Re₂(CO)₁₀ under similar conditions. cis-[Mn(CO)₄X(dpsm)] (X = Cl, Br, or I) and [Mn₂(CO)₈Br₂(μ-dmsm)] were also prepared from the appropriate [Mn(CO)₅X], but iron carbonyl halide derivatives were too unstable to isolate in the pure state. The complexes have been characterized by elemental analysis, IR and multinuclear NMR (¹H, ¹³C{¹H}, ⁵⁵Mn, or ⁵⁹Co) spectroscopy, and FAB mass spectrometry. The X-ray structures of dpsm, [Fe(CO)₄(η¹-dpsm)], and [Co₂-(CO)₄(μ-CO)₂(μ-dmsm)] have been determined. No evidence for chelation by dmsm or dpsm was found, and Sb-C fission does not occur to significant extents in the reactions studied.

Full text of DOI:10.1021/om9706121

Organometallics 1997, 16, 5641-5647
5641
Com p lexes of Distibin om eth a n e Liga n d s. 1. Ir on ,
Coba lt, Nick el, a n d Ma n ga n ese Ca r bon yl Com p lexes
Angela M. Hill, William Levason,* Michael Webster, and Isabel Albers†
Department of Chemistry, University of Southampton, Southampton SO17 1BJ , U.K.
Received J uly 17, 1997X
The reaction of Fe2(CO)9 in thf with Ph2SbCH2SbPh2 (dpsm) or Me2SbCH2SbMe2 (dmsm)
produced [Fe(CO)4(η1-dpsm)] and [Fe(CO)4(µ-dmsm)Fe(CO)4], and Co2(CO)8 reacted with
either distibine ligand (L-L) to give [Co2(CO)4(µ-CO)2(µ-L-L)]. Ni(CO)4 and dpsm gave [Ni-
(CO)3(η1-dpsm)] and [Ni(CO)3(µ-dpsm)Ni(CO)3], while with dmsm only [Ni(CO)3(µ-dmsm)-
Ni(CO)3] was isolated. Mn2(CO)10 reacted slowly with dpsm or dmsm in the presence of a
[{(Cp)Fe(CO)2}2] catalyst to give [Mn2(CO)8(L-L)], but no reaction occurred with Re2(CO)10
under similar conditions. cis-[Mn(CO)4X(dpsm)] (X ) Cl, Br, or I) and [Mn2(CO)8Br2(µ-dmsm)]
were also prepared from the appropriate [Mn(CO)5X], but iron carbonyl halide derivatives
were too unstable to isolate in the pure state. The complexes have been characterized by
elemental analysis, IR and multinuclear NMR (1H, 13C{1H}, 55Mn, or 59Co) spectroscopy,
and FAB mass spectrometry. The X-ray structures of dpsm, [Fe(CO)4(η1-dpsm)], and [Co2-
(CO)4(µ-CO)2(µ-dmsm)] have been determined. No evidence for chelation by dmsm or dpsm
was found, and Sb-C fission does not occur to significant extents in the reactions studied.
In tr od u ction
groups being derived from degradation of Ph2SbCH2-
SbPh2. We report here the synthesis of new complexes
and a reinvestigation of some reported complexes15 of
dpsm and dmsm with a variety of metal carbonyls and
their detailed characterizations. Where appropriate
comparisons are drawn with the analogous diphosphi-
nomethane ligands.
The coordination chemistry of bis(diphenylphosphi-
no)methane (dppm), Ph2PCH2PPh2, has been inten-
sively investigated.1,2 In contrast to diphosphines with
two or three carbon backbones which usually chelate
to metal centers, the presence of a single methylene
linkage in dppm sufficiently disfavors chelation through
the strain in the four-membered ring that monodentate
or bridging bidentate coordination are often preferred.
Ligands with similar architecture such as Me2PCH2-
PMe2 (dmpm), Ph2AsCH2AsPh2, 2-Ph2PC5H4N, or Ph2-
PCH2PPhCH2PPh2 have been used to assemble bi- or
polymetallic complexes.2,3 Bis(di-R-stibino)methanes,
Ph2SbCH2SbPh2 (dpsm), and Me2SbCH2SbMe2 (dmsm)
were reported4 in the 1970s and a small number of
complexes with limited characterization have been
prepared.5-13 The only structurally characterized com-
plex of these ligands is14 [Pd2(µ-Ph2SbCH2SbPh2)2(σ-
Ph)2Cl2], which is a face-to-face dimer obtained by
photolysis of cis-[Pd(Ph2SbCH2SbPh2)2Cl2], the σ-Ph
Resu lts a n d Discu ssion
Bis(diphenylstibino)methane was made by reaction of
NaSbPh2 and CH2Cl2 in liquid ammonia.4 It is an air-
stable white solid, readily soluble in chlorocarbons, less
soluble in cold alcohols. The δ(CH2) resonance (CDCl3
1
solution) lies at 2.1 ppm in the H NMR and at 4.5 ppm
in the 13C{1H} spectra, both shifting in characteristic
ways on coordination. Bis(dimethylstibino)methane
was made in poor yield from NaSbMe2 and CH2Cl2 in
liquid ammonia16 or more conveniently from Cl2SbCH2-
17
SbCl2 and MeMgI in diethyl ether, the yield being
improved by using MeMgI/Me2NCH2CH2NMe2. The
reaction of MeLi with Cl2SbCH2SbCl2 also affords the
ligand in poor yield. The ligand is a pyrophoric oil which
must be handled with rigorous exclusion of oxygen. The
1H NMR spectrum (CDCl3 solution) has δ(CH2) at 1.1
ppm and δ(Me) at 0.8 ppm, with corresponding reso-
nances at -4.3 and -1.6 ppm in the 13C{1H} NMR
spectrum. The low-frequency 13C{1H} Me and CH2
NMR resonances are typical of these groups bonded to
heavy atoms such as I or Te.18 The crystal structure of
Ph2SbCH2SbPh2 is shown in Figure 1, and selected bond
† ERASMUS student.
X Abstract published in Advance ACS Abstracts, November 15, 1997.
(1) Puddephatt, R. J . Chem. Soc. Rev. 1983, 12, 99.
(2) Chaudret, B.; Delavaux, B.; Poilblanc, R. Coord. Chem. Rev.
1988, 86, 191.
(3) Balch, A. L. Prog. Inorg. Chem. 1993, 41, 239.
(4) Matsumura, Y.; Okawara, R. J . Organomet. Chem. 1970, 25, 439;
Inorg. Nucl. Chem. Lett. 1969, 5, 449.
(5) Borowski, R.; Rehder, D.; von Deuten, K. J . Organomet. Chem.
1981, 220, 45.
(6) Beall, T. W.; Houk, L. W. J . Organomet. Chem. 1973, 56, 261.
(7) Fukumoto, T.; Matsumura, Y.; Okawara, R. J . Organomet. Chem.
1972, 37, 113.
(8) Breunig, H. J .; Fichtner, W.; Knobloch, T. P. Z. Anorg. Allg.
Chem. 1978, 445, 215.
(9) Fukumoto, T.; Matsumura, Y.; Okawara, R. Inorg. Nucl. Chem.
Lett. 1973, 9, 711.
(10) Fukumoto, T.; Matsumura, Y.; Okawara, R. J . Organomet.
Chem. 1974, 69, 437.
(15) For a review see: Champness, N. R.; Levason, W. Coord. Chem.
Rev. 1994, 133, 115.
(16) Sato, S.; Matsumura, Y.; Okawara, R. Inorg. Nucl. Chem. Lett.
(11) Beall, T. W.; Houk, L. W. Inorg. Chem. 1974, 13, 2549.
(12) Levason, W.; McAuliffe, C. A. J . Coord. Chem. 1974, 4, 47.
(13) Garrou, P.; Hartwell, P. E. J . Organomet. Chem. 1974, 69, 445.
(14) Chiffey, A. F.; Evans, J .; Levason, W.; Webster, M. Organome-
tallics 1995, 14, 1522.
1972, 8, 837.
(17) Matsumura, Y.; Okawara, R. Inorg. Nucl. Chem. Lett. 1971, 7,
113.
(18) Cheremisin, A. A.; Schastnev, P. V. J . Magn. Reson. 1980, 40,
459.
S0276-7333(97)00612-2 CCC: $14.00 © 1997 American Chemical Society

5642 Organometallics, Vol. 16, No. 26, 1997
Hill et al.
F igu r e 2. Molecular structure of [Fe(CO)4(Ph2SbCH2-
SbPh2)] showing the atom labeling scheme. H atoms have
not been drawn for clarity, and the thermal ellipsoids are
drawn at the 50% probability level.
F igu r e 1. Molecular structure of Ph2SbCH2SbPh2 showing
the atom labeling scheme. H atoms have not been drawn
for clarity, and the thermal ellipsoids are drawn at the 50%
probability level.
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for [F e(CO)4(P h 2SbCH2SbP h 2)]
Sb(1)-Fe(1)
Sb(1)-C(5)
Sb(1)-C(6)
Sb(1)-C(12)
Fe(1)-C
2.491(2)
2.144(9)
2.132(8)
2.119(8)
1.773(9)-1.79(1)
1.36(1)-1.41(1)
Sb(1)‚‚‚Sb(2)
Sb(2)-C(5)
Sb(2)-C(18)
Sb(2)-C(24)
C-O
3.4806(9)
2.160(8)
2.156(8)
2.150(9)
1.13(1)-1.17(1)
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for P h 2SbCH2SbP h 2
Sb(1)-C(1)
Sb(1)-C(7)
Sb(1)-C(13)
Sb(1)‚‚‚Sb(2)
2.157(3)
2.144(4)
2.169(4)
3.692(1)
Sb(2)-C(13)
Sb(2)-C(14)
Sb(2)-C(20)
C-C
2.155(4)
2.157(4)
2.161(3)
1.369(6)-1.416(5)
C-C
Sb(1)-Fe(1)-C(1)
Sb(1)-Fe(1)-C(2)
Sb(1)-C(5)-Sb(2)
87.6(3)
176.9(3)
107.9(3)
Sb(1)-Fe(1)-C(3)
Sb(1)-Fe(1)-C(4)
91.2(3)
87.0(3)
Sb(1)-C(13)-Sb(2)
C-Sb-C
117.3(2)
94.4(1)-98.7(1)
116.4(3)-125.0(3)
118.1(3)-121.6(3)
Sb-C-C
Fe(1)-C-O
Fe(1)-Sb(1)-C 112.5(2)-117.6(2) Sb-C-C
C-Sb(1)-C 100.8(3)-106.8(3) C-C-C
175.2(7)-179.4(9) C-Sb(2)-C
96.5(3)-97.7(3)
116.4(6)-124.3(6)
118.4(9)-121.1(9)
C-C-C
lengths and angles are in Table 1. The Sb-C distances
do not vary markedly (2.144(4)-2.169(4) Å), and there
is no evidence that Sb-C(H2) is different from the rest.
The key points are the Sb(1)‚‚‚Sb(2) distance (3.692(1)
Å), the angle at the methylene group (117.3(2)°), and
the C-Sb-C angles (94.4(1)-98.7(1), 96.7° average).
The structures of the phosphorus19 and arsenic20 ligands
have been reported, the latter in {(C6F5)2Hg}2‚Ph2-
AsCH2AsPh2 where there is a weak association between
Hg and As. The P-C-P and As-C-As angles are
106.2(3)° and 113(3)°, respectively.
Ir on Com p lexes. [Fe(CO)4(dpsm)] was originally
prepared7 directly from Fe(CO)5 and dpsm in refluxing
n-heptane; in our hands, the yield was ca. 5%. Better
yields (ca. 10%) were obtained using catalysts such as
NaBH4/EtOH21 or [{(Cp)Fe(CO)2}2],22 but the complex
is best made (40%) from Fe2(CO)9 in tetrahydrofuran
(thf)23 in a 1:1 Fe2(CO)9:dpsm ratio (half the contained
iron is lost as Fe(CO)5). The orange solid is very soluble
in organic solvents and in CH2Cl2 solution, and it
exhibited three IR-active ν(CO) bands at 2042 (m), 1970
(w), and 1932 (s) cm-1 consistent with an axially
substituted tbp (theory 2A1 + E) (Cf [Fe(CO)4(Ph3Sb)]24)
and, hence, η1-coordinated dpsm. In a Nujol mull, four
ν(CO) bands are present at 2043 (m), 1970 (w), 1940
(s), and 1920 (m) cm-1, an effect observed in several
[Fe(CO)4(η1-diphosphine)] complexes25 due to the bulky
ligand reducing the symmetry at the metal center. The
single δ(CO) 13C{1H} NMR resonance at 213.3 ppm
indicates fluxionality of the carbonyl groups. The
structure was confirmed by an X-ray study which
showed the η1 coordination (see Figure 2 and Table 2).
Sb(1) occupies an axial site of the tbp surrounding the
iron, and there is no difference between the Fe-C axial/
equatorial values, unlike the [Fe(CO)4(SbPh3)] complex26
where there is a slightly shorter axial Fe-C distance.
The Sb-Fe distance (2.491(2) Å) is comparable to the
value in the SbPh3 complex (2.472(1) Å). The complex
illustrates the changes that occur to the C-Sb-C angles
on coordination, where the bonded Sb(1) has larger
angles than Sb(2). Values for the uncoordinated anti-
mony (Sb(2)) are comparable with the free ligand (see
Tables 1 and 2). The Sb‚‚‚Sb distance shortens (by 0.211
Å) on complex formation, and the related Sb-C-Sb
angle becomes smaller. The corresponding diphosphine
(19) Schmidbaur, H; Reber, G.; Schier, A.; Wagner, F. E.; Mu¨ller,
G. Inorg. Chim. Acta 1988, 147, 143.
(20) Canty, A. J .; Gatehouse, B. M. J . Chem. Soc., Dalton Trans.
1972, 511.
(21) Chatt, J .; Leigh, G. J .; Thankarajan, N. J . Organomet. Chem.
1971, 29, 105.
(24) Martin, L. R.; Einstein, F. W. B.; Pomeroy, R. K. Inorg. Chem.
1985, 24, 2777.
(25) Wegner, A. P. A.; Evans, L. F.; Haddock, J . Inorg. Chem. 1975,
(22) Albers, M. O.; Colville, N. J . J . Organomet. Chem. 1982, 233,
261.
(23) Cotton, F. A.; Troup, J . M. J . Am. Chem. Soc. 1974, 96, 3438.
14, 192.
(26) Bryan, R. F.; Schmidt, W. C. J . Chem. Soc., Dalton Trans. 1974,
2337.

Fe, Co, Ni, and Mn Carbonyl Complexes
Organometallics, Vol. 16, No. 26, 1997 5643
complex structure has been determined27 and is iso-
morphous with the Sb compound, but here the P-C-P
angle (112.6(4)°) is larger than that in the free ligand19
(106.2(3)°).
a single δ(CO) resonance, again showing fluxional
carbonyl groups. Structures analogous to I are formed
by several diphosphines25 [Fe2(CO)8{Ph2P(CH2)nPPh2}]
(n ) 2-4), but in contrast dmpm produces [Fe2(CO)7-
(dmpm)] and [Fe2(CO)5(dmpm)2] which have Fe-Fe
bonds and bridging dmpm.28 Unlike the dpsm analogue,
[Fe2(CO)8(dmsm)] does not decompose to the 1:1 complex
in solution.
Prolonged reflux of [Fe(CO)4(dpsm)] with a large
excess of Fe(CO)5 in toluene, even in the presence of
catalysts, resulted mainly in recovery of the starting
materials. On a few occasions the 1H and 13C{1H} NMR
spectra of the crude products showed that a second
Coba lt Com p lexes. The reaction of dpsm or dmsm
with Co2(CO)8 in benzene gave [Co2(CO)6(L-L)] (L-L )
dpsm or dmsm).10 The red-brown solids are easily
soluble in organic solvents, although the dpsm complex
decomposes slowly in solution. The [Co2(CO)6(dpsm)]
complex exhibits three terminal and two bridging CO
vibrations in the IR spectra in both the solid and CH2-
Cl2 solution, consistent with a [(CO)2Co(µ-CO)2(µ-R2-
SbCH2SbR2)Co(CO)2] structure (II).29 The IR spectrum
of [Co2(CO)6(dmsm)] in CH2Cl2 was similar, but in a
Nujol mull or KBr disc this complex exhibited five
terminal and three bridging CO vibrations. No evidence
of a second complex was found in the NMR spectra. The
X-ray structure of this complex reveals molecules with
structure II, and thus the extra IR bands are tentatively
attributed to a second conformer (as seen in complexes
with longer backbones29). The δ(CH2) resonances in
1
species was present with δ(CH2) at 2.5 in the H NMR
spectrum and at 5.9 ppm in the 13C{1H} NMR spectrum,
with δ(CO) at 213.5 ppm. The reaction of dpsm with
Fe2(CO)9 (1:2) in thf formed a brown solid containing
larger amounts of the second product mixed with [Fe-
(CO)4(dpsm)]. The FAB mass spectrum of this material
showed very weak features at m/ z 903 and 874 and a
strong feature at m/ z ca. 790 with the appropriate
isotope patterns for [Fe2(dpsm)(CO)8]+, [Fe2(dpsm)-
(CO)7]+, and [Fe2(dpsm)(CO)4]+, respectively. Attempts
to drive this reaction to completion failed, and in
solution the material decomposed quite rapidly to [Fe-
(CO)4(dpsm)], preventing chromatographic separation.
The second complex is clearly [Fe(CO)4(µ-dpsm)Fe-
(CO)4], and the very similar IR spectrum to that of [Fe-
(CO)4(dpsm)] confirms the structure as ligand-bridged
with two isolated axially substituted tbp tetracarbonyl-
iron groups (I). Similar complexes are known with
1
both the H and 13C{1H} NMR spectra of [Co2(CO)6(L-
L)] show low-frequency coordination shifts which may
correlate with a sharper Sb-C-Sb angle. In both
complexes, a single δ(CO) resonance shows the carbonyl
groups to be fluxional. The 59Co NMR spectra show very
broad resonances (w1/2 ca. 12000-14000 Hz) at δ -1820
(dpsm) and -1710 (dmsm), which may be compared
with -2100 in [Co2(CO)8].30 Although [Co2(CO)4(L-L)2]
complexes are known with some diphosphines,29 at-
tempts to substitute more carbonyl groups with
distibinomethanes failed. A solution of [Co2(CO)6-
(dpsm)] in benzene containing excess dpsm was moni-
tored by solution IR spectroscopy over 24 h; the ν(CO)
frequencies of the starting material were slowly lost, but
with no new ν(CO) appearing, indicating decomposition
to carbonyl-free products. The crystal structure of [Co2-
(CO)6(dmsm)] is shown in Figure 3, and selected bond
lengths and angles in Table 3. The structure shows the
expected bridging Sb ligand and two bridging carbonyl
groups. The Co-Co distance (2.472(3) Å) is very similar
to that found31 in [Co2(CO)6{Me2AsCdC(AsMe2)CF2-
CF2}] (2.483(4) Å). There is no crystallographic sym-
metry, but the molecule approximates to CS with the
mirror plane passing through C(3), C(4), and C(9).
Sb(1), Sb(2), Co(1), and Co(2) are nearly coplanar, with
C(3) and C(9) forming a “shallow boat” conformation.
Nick el Com p lexes. The reaction of Ni(CO)4 with
dpsm in a 1:1 ratio in CHCl3 at ambient temperatures
produced white [Ni(CO)3(dpsm)], which has two ν(CO)
in the IR spectrum, consistent (theory A1 + E) with the
expected structure III.32 In solution, the complex
partially decomposes into Ni(CO)4 and free ligand, the
Ph2P(CH2)nPPh2 (n g 2),25 but with Ph2PCH2PPh2 the
dinuclear complex [Fe2(CO)7(Ph2PCH2PPh2)], which
contains an Fe-Fe bond and a bridging CO ligand, is
formed.23
In contrast to the reaction with dpsm, the reaction of
dmsm with Fe(CO)5 or Fe2(CO)9 gave only yellow-brown
[Fe2(CO)8(µ-dmsm)]. The carbonyl region of the IR
spectrum shows three ν(CO) stretches consistent with
axially substituted tbp iron centers, and the single
(28) King, R. B.; RaghuVeer, K. S. Inorg. Chem. 1984, 23, 2482.
(29) Thornhill, D. J .; Manning, A. R. J . Chem. Soc., Dalton Trans.
1973, 2086.
1
resonances for the Me and CH2 groups in the H NMR
(30) 59Co 100%, I ) 7/2, ¥ ) 23.73 MHz, Dc ) 1.56 × 103, Q ) 0.42
× 10-28 m2; Multinuclear NMR; Mason, J ., Ed.; Plenum: New York,
1987.
and 13C{1H} spectra show that dmsm is symmetrically
bridging (structure I). The 13C{1H} NMR spectrum has
(31) Harrison, W.; Trotter, J . J . Chem. Soc. A 1971, 1607.
(32) Delbecke, F. T.; Van der Kelen, G. P.; Eeckhout, Z. J . Orga-
nomet. Chem. 1974, 64, 265.
(27) Dias Rodrigues, A. M. G.; Lechat, J . R.; Francisco, R. H. P. Acta
Crystallogr., Sect. C 1992, C48, 159.

5644 Organometallics, Vol. 16, No. 26, 1997
Hill et al.
F igu r e 4. 13C{1H} NMR spectrum of [Ni2(CO)6(dmsm)] in
CHCl3: (*) resonances attributed to [Ni2(CO)6(dmsm)], (()
resonances attributed to [Ni(CO)3(η1-dmsm)].
F igu r e 3. Molecular structure of [Co2(CO)6(Me2SbCH2-
SbMe2)] showing the atom labeling scheme. H atoms have
not been drawn for clarity, and the thermal ellipsoids are
drawn at the 50% probability level.
of CO had stopped, a clear viscous oil identified by
analysis and mass spectrometry as [Ni2(CO)6(dmsm)]
was obtained. Once isolated, the oil appears to be stable
under nitrogen at -20 °C for some weeks but the initial
reaction mixture turns black in a few hours. The IR
spectrum of the oil, both in a mull and in solution, shows
two ν(CO) bands, as expected for structure IV. On
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for [Co2(CO)6(Me2SbCH2SbMe2)]
Sb(1)-Co(1)
Sb(1)‚‚‚Sb(2)
Sb(1)-C(7)
Sb(1)-C(8)
Sb(1)-C(9)
Co(1)-C(1)
Co(1)-C(2)
Co(1)-C(3)
Co(1)-C(4)
2.508(2)
3.572(2)
2.08(2)
2.12(2)
2.10(2)
1.77(2)
1.82(2)
1.90(2)
1.92(2)
Sb(2)-Co(2)
Co(1)-Co(2)
Sb(2)-C(9)
Sb(2)-C(10)
Sb(2)-C(11)
Co(2)-C(3)
Co(2)-C(4)
Co(2)-C(5)
Co(2)-C(6)
2.529(2)
2.472(3)
2.15(2)
2.09(2)
2.11(2)
1.93(2)
1.91(2)
1.82(2)
1.75(2)
1
standing, the solution decomposes; the H NMR spec-
trum in CDCl3 shows five singlets at δ 0.8(, 0.9(, 1.1*,
1.45(, and 1.6* and singlets in the 13C{1H} NMR
spectrum at δ 197.1(, 196.6*, 192.0 (Ni(CO)4), 0.4*,
-0.1(, -1.45(, -3.37*, and -3.81( (Figure 4). From the
relative intensities and shift patterns we assign the
resonances marked by an asterisk (*) to [Ni2(CO)6-
(dmsm)] and a solid diamond (() to [Ni(CO)3(η1-dmsm)],
the latter having structure III. Unfortunately, the
reaction does not go to completion and a pure sample
of the 1:1 complex has not been isolated. The reaction
of Me2PCH2PMe2 with Ni(CO)4 produces the chelate
[Ni(CO)2(Me2PCH2PMe2)]28 as a white powder sublim-
able in vacuum, but when [Ni2(CO)6(dmsm)] was heated
in vacuo (100 °C/10-3 mmHg), it pyrolyzed to a black
carbonyl-free solid.
Sb(1)-C(9)-Sb(2)
Sb(1)-Co(1)-C(1)
Sb(1)-Co(1)-C(2)
Sb(1)-Co(1)-C(3)
Sb(1)-Co(1)-C(4)
Co(1)-C(3)-O(3)
Co(2)-C(3)-O(3)
114.5(7)
104.5(5)
89.6(5)
151.1(6)
86.1(4)
141(1)
Sb(2)-Co(2)-C(3)
Sb(2)-Co(2)-C(4)
Sb(2)-Co(2)-C(5)
Sb(2)-Co(2)-C(6)
Co(1)-C(4)-O(4)
Co(2)-C(4)-O(4)
151.0(5)
85.0(5)
90.1(5)
107.0(5)
139(1)
139(1)
141(1)
Co-Sb-C(9) 109.0(4), 107.2(4) C-Sb(2)-C
99.0(7)-102.3(6)
Co-Sb-C(n*) 119.7(5)-123.4(5) Co-C-O (term) 174(1)-178(1)
C-Sb(1)-C
100.0(6)-102.4(7)
a
n ) 7, 8, 10, or 11.
Ma n ga n ese Com p lexes. Initial attempts to react
Mn2(CO)10 and dpsm either photochemically in n-
hexane or thf or thermally in n-hexane or ethanol failed.
The thermal reaction in toluene using [{(Cp)Fe(CO)2}2]22
as a catalyst produced moderate yields of orange [Mn2-
(CO)8(dpsm)], which was separated from unreacted
starting materials by crystallization from CH2Cl2-n-
hexane. There was no evidence for other products,
although with diphosphines (L-L),37 [Mn2(CO)8(L-L)],
[Mn2(CO)6(L-L)2], [Mn2(CO)5(dppm)2], and mononuclear
products form. The IR spectrum of the complex as a
Nujol mull shows five terminal and no bridging carbonyl
stretches, and the structure is identified as V. Consis-
tent with this structure, the 13C{1H} NMR spectrum
shows three carbonyl resonances in the approximate
ratio 1:1:2. The δ(CH2) at 3.3 (1H) and 21.1 (13C{1H})
have shifted considerably to high frequency compared
with other complexes, and presumably this reflects the
effect of the five-membered metallocyclic ring. Unfor-
tunately, we have been unable to grow crystals of this
tetracarbonyl being identified by a δ(13C{1H}) resonance
at 192.0 and the T1u mode at 2043 cm-1 in the IR
spectrum.33-35
The reaction of dpsm with excess Ni(CO)4 produced
a colorless waxy solid identified as [Ni2(CO)6(dpsm)].
The IR spectrum of this complex in both Nujol mulls or
CH2Cl2 solution was very similar to that of the 1:1
complex, as expected for structure IV. An analogue
[Ni2(CO)6(Ph2PPPh2)] has been characterized by an
X-ray study.36 On standing in CH2Cl2 solution, the
complex partially decomposes into [Ni(CO)3(dpsm)] and
Ni(CO)4.35
If the reaction mixture of excess Ni(CO)4 with dmsm
in CHCl3 was worked up immmediately after evolution
(33) Bodner, G. M.; May, M. P.; McKinney, L. E. Inorg. Chem. 1980,
19, 1951.
(34) Noak, K. Helv. Chim. Acta 1962, 45, 1847.
(35) Mass balance requires that other product(s) form, but none were
identified, although a grey precipitate was sometimes seen in the NMR
tubes.
(36) Mais, R. H. B.; Owston, P. G.; Thompson, D. T.; Wood, A. M. J .
Chem. Soc. A 1967, 1744.
(37) (a) Colton, R.; Commons, C. J . Aust. J . Chem. 1975, 28, 1673.
(b) Reimann, R. H.; Singleton, E. J . Organomet. Chem. 1972, 38, 113.

Fe, Co, Ni, and Mn Carbonyl Complexes
Organometallics, Vol. 16, No. 26, 1997 5645
complex for an X-ray study which would reveal the
detailed conformation. Literature examples38 with this
metal center whereas the phosphine analogues often
replace more than one. Moreover, the reactions involv-
ing the stibines are relatively slow and give poor to
moderate yields, suggestive of the weak donor power of
the antimony. For isostructural complexes, the ν(CO)
frequencies are slightly lower in the stibine complexes
compared to the phosphines. The familiar synergic
bonding model for the M-CO linkage would attribute
lower ν(CO) frequencies to better σ-donation or poorer
π-acceptance by the coligands, leading to increased
π-acceptance by the CO groups. The poor reactivity of
the stibines do not provide support for good σ-donor
power, and weaker π-acceptance by the stibine is the
most likely effect, as concluded by others in tertiary
stibine systems.15,33
It should be noted that the low yields do not reflect
side reactions; in the majority of cases, monitoring the
reactions over time via IR spectroscopy in the carbonyl
region and/or NMR spectroscopy of the crude products
revealed that only the products described and unreacted
reagents were present in significant amounts. C-Sb
bond fission was not observed in the reactions described,
which was unexpected given the ease with which such
fission occurs for Ph3Sb on reaction with platinum metal
halides14,43 and in some carbonyl systems including
Fe(CO)5.44
structure are [Mn2(CO)8{Me2AsCdC(AsMe2)CF2CF2}]
and [Mn2(CO)8(Ph2AsCH2AsPh2)]. [Mn2(CO)8(dmsm)]
was made by an analogous route in higher yield and is
spectroscopically very similar. Both complexes exhib-
ited very broad 55Mn NMR resonances39 at δ -2195
(dpsm) and -2317 (dmsm), which may be compared
with that in [Mn2(CO)10] (δ -2353).39
When Re2(CO)10 and dpsm were heated together in
toluene in the presence of [{(Cp)Fe(CO)2}2], no reaction
was observed after 96 h.
Ca r bon yl Ha lid es. The reaction of [FeCl2(CO)4]
with dpsm in CH2Cl2 at room temperature produced an
unstable orange solid which had ν(CO) at 2018 and 1969
cm-1 in a Nujol mull and at 2027 and 1980 cm-1 in CH2-
Cl2 solution. The complex decomposed with complete
loss of the carbonyl groups in a few hours in CH2Cl2
solution and over a period of days in the solid state.
From the very similar IR spectrum to that40 of [FeBr2-
(CO)2(SbPh3)2] it seems probable that the complex is
[FeCl2(CO)2(η1-dpsm)2], but due to the solution instabil-
ity we have been unable to obtain an analytically pure
sample. No complex was obtained from the correspond-
ing reaction with [FeI2(CO)4].
In contrast, stirring [Mn(CO)5X] (X ) Cl, Br, or I) with
dpsm in CH2Cl2 at room temperature produced orange-
red powders cis-[Mn(CO)4X(dpsm)] in good yield. For
a cis tetracarbonyl arrangement,41 four IR-active ν(CO)
vibrations are expected (theory 2A1 + B1 + B2) and in
practice three or four were observed (Experimental
Section). The NMR spectra are consistent with η1-dpsm,
and the 55Mn NMR show a single broad resonance for
each complex, shifted to low frequency from those42 of
the parent [Mn(CO)5X] compound. A similar reaction
between [Mn(CO)5Br] and dmsm in a 2:1 molar ratio
gave red [Mn2(CO)8Br2(dmsm)], which has very similar
spectroscopic properties and is assigned a related struc-
ture with dmsm bridging two cis-Mn(CO)4Br units.
Exp er im en ta l Section
P h ysica l Mea su r em en ts. 1H NMR spectra (300 MHz)
were recorded on a Bruker AC300 in CDCl3 solutions and were
referenced to the residual 1H solvent resonance. 13C{1H} NMR
spectra (90.6 MHz) were obtained on a Bruker AM360 from
CHCl3/CDCl3 or CH2Cl2/CDCl3 solutions using a 2 s pulse
delay, with added Cr(acac)3 as a relaxation agent, and refer-
enced to CDCl3. 55Mn (89.4 MHz) and 59Co (68.7 MHz) were
obtained on a Bruker AM360 from CHCl3/CDCl3 solutions and
referenced to external aqueous KMnO4 and K3[Co(CN)6],
respectively. IR spectra were obtained as Nujol mulls between
NaCl plates for solid samples and from CH2Cl2 solutions in 1
mm NaCl solution cells on a Perkin Elmer Paragon 1000. FAB
mass spectra were obtained on a VG Analytical 70-250-SE
double-focusing mass spectrometer using 3-NOBA as the
matrix. Analyses were by the microanalytical service of
Imperial College, London.
Con clu sion s
Three coordination modes of the distibinomethanes
have been established, viz, monodentate to a single
metal center, bridging bidentate between two otherwise
unconnected metal centers, and bridging a M-M-
bonded system, but no examples of chelation. The
diphosphine analogues, R2PCH2PR2, exhibit all four
bonding modes in appropriate systems.1,2 The results
are consistent with increased strain in the four-
membered ring as the donor atom size increases,
exacerbated by the weaker bonds being less able to
overcome this strain. In the majority of cases, the
stibine only substitutes a single carbonyl group per
P h 2SbCH2SbP h 2 was made as previously described4 (62%)
as white air-stable crystals. 1H NMR (CDCl3): 2.5 (s, 2H),
7.2-7.6 (m, 20H). 13C{1H} NMR (CHCl3): 4.5, 129.0, 136.0,
139.0. EI MS: m/ z 566, 198, 154. Calcd for C25H22121Sb2 564,
C6H5121Sb 198, C12H10 154.
Me2SbCH2SbMe2 was made from NaSbMe2 and CH2Cl2 in
liquid ammonia as previously described4 (21%). An alternative
route based upon that of Matsumura and Okawara17 was more
convenient. dpsm (20.0 g, 35.5 mmol) was dissolved in dry
CHCl3 (100 cm3) and saturated with dry hydrogen chloride at
0 °C. The white precipitate (Cl2SbCH2SbCl2) was isolated by
Schlenk filtration and dried in vacuo (13.0 g, 93%). To the
Grignard reagent prepared from magnesium (3.12 g, 0.13 mol)
and iodomethane (18.5 g, 0.13 mol) in diethyl ether (200 cm3)
and dry N,N,N′,N′-tetramethylethylenediamine (15.1 g, 0.13
mol) was added dropwise a solution of Cl2SbCH2SbCl2 (13.0
g, 0.033 mol) in diethyl ether (200 cm3), and the yellowish-
green solution stirred at room temperature for 4 h and then
heated to reflux for 15 min. The mixture was cooled and
(38) (a) Chan, L. Y. Y.; Einstein, F. W. B. J . Chem. Soc., Dalton
Trans. 1973, 111. (b) Hoskins, B. F.; Steen, R. J . Aust. J . Chem. 1983,
36, 683. (c) Morgan, C. A.; Fanwick, P. E.; Rothwell, I. P. Inorg. Chim.
Acta 1994, 224, 105.
(39) 55Mn 100% I ) 5/2, ¥ ) 24.8 MHz, Dc ) 1 × 103, Q ) 0.55 ×
10-28 m2; Pregosin, P. S. Transition Metal Nuclear Magnetic Resonance;
Elsevier: Amsterdam, 1991.
(40) Hieber, W.; Thalhofer, A. Angew. Chem. 1956, 68, 679. Cohen,
I. A.; Basolo, F. J . Inorg. Nucl. Chem. 1966, 28, 511.
(41) (a) Angelici, R. J .; Basolo, F. J . Am. Chem. Soc. 1962, 84, 2495.
(b) Smith, F. E.; Butler, I. S. Can. J . Chem. 1969, 47, 1311.
(42) Calderazzo, F.; Lucken, E. A. C.; Williams, D. F. J . Chem. Soc.
A 1967, 154. [Mn(CO)5Cl] δ ) -1005, [Mn(CO)5Br] δ ) -1160, [Mn-
(CO)5I] δ ) -1485.
(43) (a) Chini, R.; Giorgi, G.; Perriccioli, L. Inorg. Chim. Acta 1992,
196, 7. (b) Mentes, A.; Kemmitt, R. D. W.; Fawcett, J .; Russell, D. R.
J . Organomet. Chem. 1997, 528, 59.
(44) Cane, D. J .; Forbes, E. J .; Silver, J . J . Organomet. Chem. 1977,
129, 181.

5646 Organometallics, Vol. 16, No. 26, 1997
Hill et al.
hydrolyzed with deoxygenated saturated ammonium chloride
solution (200 cm3). The organic layer was separated and dried
(MgSO4), and the solvent was removed by distillation under
nitrogen. The residue was fractionated in vacuo at 40 °C/0.2
torr to yield Me2SbCH2SbMe2 (2.5 g, 24%) as a colorless,
pyrophoric oil. 1H NMR (CDCl3): 1.1 (s, 2H), 0.8 (s, 12H). 13C-
{1H} NMR (CHCl3): -1.6, -4.3. EI MS: m/ z 318, 303. Calcd
for C5H14121Sb2 316, C4H11121Sb2 301. The ligand was also made
in poor yield (ca. 15%) from Cl2SbCH2SbCl2 and MeLi in
diethyl ether.
(CDCl3): 2.3 (2H), 7.2-7.6 (20H). 13C{1H} NMR (CHCl3): 1.3,
128-139, 196.8. IR (ν(CO)): Nujol mull 2072 (m), 1999 (s)
cm-1; CH2Cl2 2072 (m), 2004 (s) cm-1
.
[Ni2(CO)6(d p sm )]. dpsm (0.566 g, 1.0 mmol) was dissolved
in CHCl3 (5 cm3), and Ni(CO)4 (0.34 g, 2.0 mmol) was added.
The mixture was stirred at room temperature for 3 h, and then
the solvent was removed in vacuo. The product was a white
waxy solid (0.68 g, 80%). Anal. Calcd for C31H22Ni2O6Sb2: C,
43.7; H, 2.6. Found: C, 43.3; H, 3.0. 1H NMR (CDCl3): 2.5
(2H), 7.2-7.6 (20H). 13C{1H} NMR (CHCl3): 2.9, 129-138,
121
All complex preparations were carried out under a nitrogen
atmosphere.
196.3. FAB MS: m/ z 738, 707, 679. Calcd for [58Ni2(Ph2
-
SbCH2121SbPh2)(CO)2] 736, [58Ni(Ph2121SbCH2121SbPh2)(CO)3]
706, [58Ni(Ph2121SbCH2121SbPh2)(CO)2] 678. IR (ν(CO)): Nujol
[F e(CO)4(d p sm )]. Fe2(CO)9 (0.46 g, 1.3 mmol) and dpsm
(0.72 g, 1.26 mmol) were stirred in thf (50 cm3) at room
temperature for 18 h. The mixture was filtered, and the
filtrate was evaporated in vacuo. The residue was dissolved
in a minimum amount of CH2Cl2, and pentane was added to
produce an orange precipitate (0.41 g, 44%). Anal. Calcd for
mull 2070 (m), 2000 (s) cm-1; CH2Cl2 2072 (m), 1998 (s) cm-1
.
[Ni2(CO)6(d m sm )]. A solution of dmsm (0.44 g, 1.4 mmol)
in CHCl3 (15 cm3) was treated with an excess of Ni(CO)4 (0.59
g, 3.5 mmol), and the mixture was stirred until evolution of
CO ceased (ca. 1 h). The excess Ni(CO)4 and the solvent were
removed in vacuo, and the residue was pumped at 10-2 mmHg
for 3 h. The product was a colorless, viscous oil which did not
solidify on cooling for some days at -20 °C (0.69 g, 82%). Anal.
Calcd for C11H14Ni2O6Sb2: C, 21.9; H, 2.3. Found: C, 21.6;
H, 2.5. 1H NMR (CDCl3): 1.1 (12H), 1.6 (2H). 13C{1H} NMR
(CHCl3): see text and Figure 4. FAB MS m/ z 602. Calcd for
[58Ni2(Me2121SbCH2121SbMe2)(CO)6] 600. IR(ν(CO)): Nujol mull
C
29H22FeO4Sb2: C, 47.4; H, 3.0. Found: C, 47.6; H, 3.1. 1H
NMR (CDCl3): 2.45, 7.4-7.8. 13C{1H} NMR (CDCl3): 5.4,
126-140, 213.3. FAB MS (3-NOBA): m/ z 734, 706. Calcd
for [56Fe(Ph2121SbCH2121SbPh2)(CO)4] 732, [P - CO] 704. IR
(ν(CO)): Nujol mull 2043 (m), 1970 (w), 1940 (s), 1920 (m)
cm-1; CH2Cl2 2042 (m), 1970 (m), 1932 (vs) cm-1
.
[F e2(CO)8(d m sm )] was prepared similarly from Fe2(CO)9
(3.3 mmol) and dmsm (1.15 mmol). After evaporation of the
solvent, the residue was dried in vacuo. It was redissolved in
CH2Cl2 and precipitated with pentane to afford a pale orange
solid, which was dried in vacuo (39%). Anal. Calcd for
2067 (m), 1994 (s); CH2Cl2 2067 (m), 1994 (s) cm-1
.
[Mn 2(CO)8(d p sm )]. Mn2(CO)10 (0.25 g, 0.65 mmol), dpsm
(0.64 g, 1.1 mmol), and [{(Cp)Fe(CO)2}2] (0.15 mmol) were
dissolved in degassed toluene (10 cm3). The mixture was
refluxed for 24 h, and then the toluene was removed in vacuo.
The residue was dissolved in a minimum amount of CH2Cl2,
n-hexane was added dropwise, and an orange solid precipi-
tated, which was isolated by filtration and dried in vacuo (0.12
g, 21%). Anal. Calcd for C33H22Mn2O8Sb2: C, 44.0; H, 2.4.
Found: C, 44.1; H, 2.1. 1H NMR (CDCl3): 3.3 (2H), 7.4-7.8
(20H). 13C{1H} NMR (CH2Cl2): 21.1, 128-135, 221.0, 224.0,
225.9. 55Mn NMR (CH2Cl2): -2195 (w1/2 20 000 Hz). FAB MS
(3-NOBA): m/ z 816, 788, 760, 732, 704, 676. Calcd for
[Mn2(Ph2121SbCH2121SbPh2)(CO)5] 814, remainder are due to
successive loss of CO groups. IR(ν(CO)): Nujol mull 2051 (m),
1985 (m), 1964 (s), 1910 (sh), 1902 (s) cm-1; CH2Cl2 2020 (w),
C
13H14Fe2O8Sb2: C, 23.9; H, 1.8. Found: C, 23.8; H, 2.1. 1H
NMR (CDCl3): 1.45, 2.2. 13C{1H} NMR (CHCl3): 1.3, 1.6,
213.6. FAB MS (3-NOBA): m/ z 598, 461. Calcd for
[56Fe2(Me2121SbCH2121SbMe2)(CO)6] 598, [P - 7CO] 458. IR
(ν(CO)): Nujol mull 2038 (s), 1961 (s), 1928 (s); CH2Cl2 2040
(s), 1963 (m), 1931 (vs) cm-1
.
[Co2(CO)6(d p sm )]. [Co2(CO)8} (0.73 g, 2.14 mmol) and
dpsm (1.21 g, 2.14 mmol) were stirred in benzene (80 cm3) at
room temperature until evolution of CO ceased (ca. 2 h). The
solvent was removed in vacuo, and the red residue was
dissolved in CH2Cl2 and filtered. The filtrate was concentrated
to 10 cm3, and n-hexane was added dropwise. The red
precipitate was isolated by filtration and dried in vacuo (1.4
g, 77%). Anal. Calcd for C31H22Co2O6Sb2: C, 43.7; H, 2.6.
Found: C, 43.8; H, 2.3. 1H NMR (CDCl3): 1.9, 7.4-7.8.
13C{1H} NMR (CH2Cl2): -2.2, 127-139, 216.5. 59Co NMR
(CH2Cl2): -1820 (w1/2 ) 14 000 Hz). FAB MS (3-NOBA): m/ z
768, 740, 712. Calcd for [Co2(Ph2121SbCH2121SbPh2)(CO)3] 766.
IR (ν(CO)): Nujol mull 2043 (s), 2006 (s),1967 (s), 1832 (s),
1773 (s) cm-1; CH2Cl2 2044 (s), 2111 (s), 1987 (s), 1825 (m),
1975 (sh), 1965 (m), 1913 (s) cm-1
.
[Mn 2(CO)8(d m sm )]. Mn2(CO)10 (0.45 g, 1.15 mmol), dmsm
(0.36 g, 1.15 mmol), and [{(Cp)Fe(CO)2}2] (0.08 g, 0.23 mmol)
were dissolved in degassed toluene (30 cm3) and refluxed for
28 h. The mixture was filtered, and the filtrate was taken to
dryness in vacuo. Recrystallization of the residue from CH2-
Cl2-n-hexane (1:10 v/v) gave a rust-colored solid (0.26 g, 35%).
Anal. Calcd for C13H14Mn2O8Sb2: C, 23.9; H, 2.2. Found: C,
24.1; H, 2.2. 1H NMR (CDCl3): 2.15 (2H), 1.3 (12H). 13C{1H}
NMR (CH2Cl2): -0.5, 16.0, 221.2, 224.2, 227.0. 55Mn NMR
(CH2Cl2): -2317 (w1/2 ) 4000 Hz). FAB MS (3-NOBA): m/ z
652, 624. Calcd for [Mn2(CO)8(Me2121SbCH2121SbMe2)] 650,
[Mn2(CO)7(Me2121SbCH2121SbMe2)] 622. IR(ν(CO)): Nujol mull
2042 (m), 2002 (sh), 1988 (sh), 1942 (s), 1899 (m) cm-1; CH2-
1772 (m) cm-1
.
[Co2(CO)6(d m sm )] was prepared similarly from [Co2(CO)8]
(0.32 g, 0.93 mmol) and dmsm (0.30 g, 0.93 mmol) in benzene
as dark red crystals (0.34 g, 61%). Anal. Calcd for C11H14
-
Co2O6Sb2: C, 21.9; H, 2.3. Found: C, 22.1; H, 2.3. 1H NMR
(CDCl3): 1.42 (2H), 1.36 (12H). 13C{1H} NMR (CH2Cl2): -7.4,
-1.3, 217.5. 59Co NMR (CH2Cl2): -1710 (w1/2 ) 12 000 Hz).
FAB MS (3-NOBA): m/ z 604, 576, 548, 520, 492, 464, 436.
Calcd for [Co2(CO)6(Me2121SbCH2121SbMe2)] 602, other peaks
are due to sequential loss of CO’s. IR (ν(CO)): Nujol mull 2031
(s), 1998 (s), 1987 (m), 1969 (s), 1947 (m), 1805 (s), 1772 (sh),
1764 (s) cm-1; CH2Cl2 2037 (s), 2003 (s), 1977 (s), 1815 (m),
Cl2 2047 (s), 1983 (s), 1961 (s), 1931 (m), 1912 (m) cm-1
.
[Mn (CO)4Cl(d p sm )]. [Mn(CO)5Cl] (0.17 g, 0.74 mmol) was
dissolved in CHCl3 (8 cm3), and dpsm (0.42 g, 0.74 mmol) was
added. The mixture was stirred for 24 h at room temperature,
and then the chloroform was evaporated in a stream of
nitrogen. The resulting oil was dried in vacuo and then
washed with n-pentane (3 × 10 cm3) producing an orange
powder, which was separated and dried in vacuo (0.41 g, 72%).
Anal. Calcd for C29H22ClMnO4Sb2: C, 45.3; H, 2.9. Found:
C, 45.8; H, 2.8. 1H NMR (CDCl3): 2.45 (2H), 7.4-7.8 (20H).
13C{1H} NMR (CH2Cl2): 2.2, 128-139, 212.3, 215.1, 219.0.
55Mn NMR (CH2Cl2): -1277 (w1/2 ) 5000 Hz). FAB MS (3-
NOBA): m/ z 654. Calcd for [Mn(Ph2121SbCH2121SbPh2)35Cl]
654. IR(ν(CO)): Nujol mull 2084 (m), 2021 (m), 2000 (s), 1932
1764 (m) cm-1
.
[Ni(CO)3(d p sm )]. (CARE: Ni(CO)4 is volatile and very
toxic. All reactions were performed in sealed vessels in a good
hood, and residues were destroyed with bromine.) dpsm (0.57
g, 1.0 mmol) was dissolved in CHCl3 (5 cm3), and Ni(CO)4 (0.17
g, 1.0 mmol) was added. The mixture was stirred at room
temperature for 3 h, and the solvent was removed in vacuo.
The white oily residue was stirred with diethyl ether (20 cm3)
producing a white powder, which was separated by filtration
and dried in vacuo (0.54 g, 76%). Anal. Calcd for C28H22NiO3-
Sb2: C, 47.4; H, 3.1. Found: C, 47.5; H, 3.0. 1H NMR
(m) cm-1; CH2Cl2 2088 (m), 2010 (s), 1954 (m) cm-1
.
[Mn (CO)4Br (d p sm )] was prepared similarly from [Mn-
(CO)5Br], although a 48 h reaction time was used (76%). Anal.

Fe, Co, Ni, and Mn Carbonyl Complexes
Organometallics, Vol. 16, No. 26, 1997 5647
Ta ble 4. Cr ysta l Da ta for P h 2SbCH2SbP h 2, [F e(CO)4(P h 2SbCH2SbP h 2)], a n d [Co2(CO)6(Me2SbCH2SbMe2)]
compound
formula
fw
Ph2SbCH2SbPh2
25H22Sb2
565.95
[Fe(CO)4(Ph2SbCH2SbPh2)]
C29H22FeO4Sb2
733.84
[Co2(CO)6(Me2SbCH2SbMe2)]
C11H14Co2O6Sb2
603.59
C
cryst syst
space group
a/Å
b/Å
c/Å
triclinic
monoclinic
P21/c (No. 14)
8.766(9)
27.820(47)
11.316(8)
90.0
96.11(7)
90.0
2744(6)
45.1-49.7
150
1.776
4
monoclinic
P21/c (No. 14)
9.050(4)
15.244(5)
12.727(5)
90.0
98.82(3)
90.0
1735.2(1.1)
19.0-23.0
150
P1h (No. 2)
10.674(5)
11.864(6)
9.368(5)
108.17(4)
90.18(4)
108.31(3)
1063.5(1.0)
49.8-51.1
150
R/deg
â/deg
γ/deg
volume/Å3
2θ range for cell/deg
T/K
Dc (calcd), g cm-3
Z
1.767
2
2.310
4
F(000)/e
548
1424
1136
cryst size/mm
scan mode
total no. of obsns
no. of unique obsns
hkl range
abs corr
0.6 × 0.6 × 0.3
0.65 × 0.60 × 0.20
0.62 × 0.1 × 0.03
ω-2θ
ω
ω-2θ
3945
5293
3395
3725 (Rint ) 0.014)
0-12, -14 to 13, -11 to 11
ψ-scan (3 refs)
0.69, 1.00
3487 (I > 3σ(I))
245
4959 (Rint ) 0.032)
0-10, 0-33, -13 to 13
ψ-scan (3 refs)
0.510, 1.000
4146 (I > 2.5σ(I))
325
3186 (Rint ) 0.126)
0-10, 0-18, -15 to 14
ψ-scan (3 refs)
0.762, 1.000
1987 (I > 3σ(I))
190
min, max transmission
no. of data in refinement
no. of params
weighting scheme (w-1
λ/Å (Mo KR)
µ/cm-1
)
σ2(Fo)
0.710 69
25.43
50.0
3.4
σ2(Fo)
0.710 69
25.05
50.0
3.00
σ2(Fo)
0.710 69
49.74
50.0
max 2θ/deg
S
2.22
max shift/esd
0.02
0.66 to -0.66
0.023, 0.037
0.01
1.20 to -2.57
0.049, 0.080
0.01
1.90 to -2.12
0.050, 0.063
resid electron density/e Å-3
R, wRa
a
2 1/2
R ) ∑||Fo| - |Fc||/∑|Fo|; wR ) [∑w(Fo - Fc)2/∑wFo
] .
Calcd for C29H22BrMnO4Sb2: C, 42.8; H, 2.7. Found: C, 42.6;
H, 3.0. 1H NMR (CDCl3): 2.55 (2H), 7.2-7.6 (20H). 13C{1H}
NMR (CH2Cl2): 3.7, 129-139, 210.5, 212 (sh), 215.8. 55Mn
NMR (CH2Cl2): -1410 (w1/2 ) 10 000 Hz). FAB MS (3-
NOBA): m/ z 698, 619. Calcd for [Mn(Ph2121SbCH2121SbPh2)-
79Br] 698. IR(ν(CO)): Nujol mull 2079 (s), 2015 (s), 1991 (s),
X-r a y St r u ct u r e of P h 2Sb CH2Sb P h 2, [F e(CO)4(P h 2-
SbCH2SbP h 2)], a n d [Co2(CO)6(Me2SbCH2SbMe2)]. Suit-
able crystals of the free ligand were grown during attempts
to grow crystals of the [W(CO)5(dpsm)] complex from CH2Cl2/
EtOH, the iron complex from a CH2Cl2 solution of the complex
on cooling, and the cobalt complex from a solution in CH2Cl2/
toluene/ether in the dark. Data were collected using a Rigaku
AFC7S diffractometer fitted with Mo KR radiation, a graphite
monochromator, and Oxford Cryosystems low-temperature
device running at 150 K, and crystal data are given in Table
4. The structures were solved using the direct methods in
SHELXS-8645 to locate the heavy atoms, and a number of light
atoms and all remaining non-H atoms were found by structure-
factor and electron-density calculations. Hydrogen atoms were
positioned geometrically (d(C-H) ) 0.95 Å) for the Fe and Co
complex but located in later electron-density maps for the free
ligand, where they were added to the model but not refined.
Full-matrix least-squares refinement on F with anisotropic
non-H atoms was carried out using the teXsan package.46
1956 (s) cm-1; CH2Cl2 2084 (m), 2006 (s), 1955 (m) cm-1
.
[Mn (CO)4I(d p sm )]. [Mn(CO)5I] (0.323 g, 1.0 mmol) was
dissolved in CHCl3 (30 cm3), and dpsm (0.57 g, 1.0 mmol) was
added. The mixture was heated to 50 °C and stirred for 24 h
at this temperature. The chloroform was evaporated in a
stream of nitrogen, and the resulting red oil was dried in
vacuo. It was washed with n-pentane (3 × 10 cm3) producing
an orange powder, which was separated and dried in vacuo
(0.57 g, 66%). Anal. Calcd for C29H22IMnO4Sb2: C, 40.4 ; H,
2.5. Found: C, 40.1; H, 2.1. 1H NMR (CDCl3): 2.85 (2H), 7.3-
7.9 (20H). 13C{1H} NMR (CH2Cl2): 5.9, 129-139, 211.7, 212.8,
218.0. 55Mn NMR (CH2Cl2): -1732 (w1/2 ) 12 000 Hz). IR
(ν(CO)): Nujol mull 2077 (m), 2011 (sh), 2001 (s), 1955 (m)
cm-1; CH2Cl2 2077 (m), 2010 (sh), 2000 (s), 1958 (m) cm-1
.
[Mn 2(CO)8Br 2(d m sm )]. [MnBr(CO)5] (0.83 g, 3.0 mmol)
was dissolved in CHCl3 (8 cm3), and dmsm (0.48 g, 1.5 mmol)
was added. The mixture was stirred at room temperature for
48 h, and then the chloroform was evaporated in a stream of
nitrogen. The resulting oil was dried in vacuo, then washed
with n-pentane (3 × 10 cm3), and an orange powder formed
(0.41 g, 34%). Anal. Calcd for C13H14Br2Mn2O8Sb2: C, 19.3;
H, 1.7. Found: C, 19.0; H, 2.0. 1H NMR (CDCl3): 1.5 (12H),
2.2 (2H). 13C{1H} NMR (CHCl3): 220.5, 216.8, 212.3, -0.2,
-5.9. 55Mn NMR (CH2Cl2): -1465 (w1/2 ) 8700 Hz). FAB MS
(3-NOBA): m/ z 540, 484, 453. Calcd for [Mn2(Me2121SbCH2-
121SbMe2)(CO)4] 538, [Mn2(Me2121SbCH2121SbMe2)(CO)2] 482,
[Mn79Br(Me2121SbCH2121SbMe2)] 450. IR(ν(CO)): Nujol mull
2079 (m), 2000 (s), 1940 (s), 1903 (m); CH2Cl2 2084 (m), 2004
Ack n ow led gm en t. We thank the EPSRC for sup-
port (A.M.H.) and for funds to purchase the X-ray
diffractometer and A. R. J . Genge for assistance.
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
data, atomic coordinates, anisotropic displacement parameters,
and bond lengths and angles (20 pages). Ordering information
is given on any current masthead page.
OM9706121
(45) Sheldrick, G. M. SHELXS-86, Program for the Solution of
Crystal Structures; University of Go¨ttingen: FRG, 1986; Acta Crys-
tallogr., Sect. A 1990, 46, 467.
(46) teXsan, crystal structure analysis package (version 1.7-1);
Molecular Structure Corp.: The Woodlands, TX, 1995.
(s), 1966 (m), 1916 (w) cm-1
.