Synthesis, spectroscopic and structural characterisation of chromium(0), molybdenum(0) and tungsten(0) complexes involving primary and secondary phosphines

Article abstract of DOI:10.1016/S0022-328X(99)00570-7

[M(CO)₆] (M=Mo or W) reacts with 4.5 molar equivalents of L (L=PPh₂H or PPhH₂) in excess ethanolic NaBH₄ to yield the fac-trisubstituted species [M(CO)₃(L)₃] in good yield, with no evidence

Full text of DOI:10.1016/S0022-328X(99)00570-7

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 592 (1999) 296–305
Synthesis, spectroscopic and structural characterisation of
chromium(0), molybdenum(0) and tungsten(0) complexes involving
primary and secondary phosphines
Tom Campbell, Alexander M. Gibson, Richard Hart, Simon D. Orchard,
Simon J.A. Pope, Gillian Reid *
Department of Chemistry, Uni6ersity of Southampton, Highfield, Southampton SO17 1BJ, UK
Received 2 August 1999; accepted 17 September 1999
Abstract
[M(CO)6] (M=Mo or W) reacts with 4.5 molar equivalents of L (L=PPh2H or PPhH2) in excess ethanolic NaBH4 to yield
1
the fac-trisubstituted species [M(CO)3(L)3] in good yield, with no evidence for species with lower degrees of substitution. IR, H-,
13C{1H}-, 31P{1H}- and 95Mo-NMR spectroscopy on these compounds, together with X-ray crystallographic studies on two
examples, confirm the fac-tricarbonyl arrangement both in solution and in the solid state. Similar reactions involving PCy2H yield
only the cis-disubstituted species [M(CO)4(PCy2H)2]. Reaction of [M%(CO)4(nbd)] (M%=Cr or Mo) or [W(CO)4(TMPA)
(TMPA=tetramethylpropylenediamine) with two molar equivalents of L (L=PPh2H, PPhH2 or PCy2H) or with one molar
equivalent of L–L (L–L=o-C6H4(PH2)2, PhHPCH2CH2PHPh or PhHPCH2CH2CH2PHPh) in warm toluene solution give
[M%(CO)4(L)2], [W(CO)4(L)2], [M%(CO)4(L–L)] or [W(CO)4(L–L)], respectively. Spectroscopic studies indicate that these all exist
as cis-disubstituted species in solution and single-crystal X-ray analyses on three examples confirm this assignment in the solid
state. The primary and secondary phosphines act as neutral two-electron donors in all cases with retention of the P–H functions.
Trends in the spectroscopic and structural data are discussed. © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Chromium; Molybdenum; Tungsten; Primary phosphines; Secondary phosphines
primary and secondary phosphines can act as suitable
templates for the synthesis of multidentate and macro-
cyclic phosphines. Thus, for example Stelzer and co-
workers have used this approach in the preparation of
tetraphosphine macrocycles, e.g. via the Pd(II) template
species [Pd(MeHPCH2CH2PHMe)2]2+ [3], while Nor-
man and co-workers and Edwards and co-workers used
a radical initiated cyclisation procedure on the Mo(0)
template species fac-[Mo(CO)3(H2PCH2CHꢁCH2)3] to
generate the macrocyclic triphosphine [12]aneP3 (1,5,9-
triphosphacyclododecane) and derivatives in high yield
[4]. Despite the crucial role played by the primary or
secondary phosphine complexes in these important re-
actions, there is still relatively little known about the
coordination chemistry of PR2H or PRH2 to metal
centres. We have investigated the coordination chem-
istry of these ligands with a variety of middle and late
transition metal ions, including Mn(I), Rh(III), Ru(II),
Os(II), Ni(II), Pd(II) and Pt(II) [5–9]. Through this
1. Introduction
In contrast to the very extensive investigations of the
coordination chemistry of mono-, bi- and polydentate
tertiary phosphines, primary and secondary phosphine
chemistry has received much less detailed study. Proba-
bly the main reason for this is that upon coordination
of the P donor atom to a metal centre, the PꢀH bond is
weakened significantly, and is thus susceptible to depro-
tonation giving phosphido species. Indeed this does
occur in the reaction of MCl2 (M=Pd or Pt) with
PPh2H, which yields the phosphido-bridged dimer
[M2Cl2(PPh2H)2(m-PPh2)2] [1]. Similarly, Au(I) salts re-
act with PPh2H or PPhH2 to yield phosphido bridged
polymers such as [{Au(m-PPh2)}2] [2]. However, if the
deprotonation can be controlled then complexes of
* Corresponding author. Fax: +44-1703-593-781.
E-mail address: gr@soton.ac.uk (G. Reid)
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00570-7

T. Campbell et al. / Journal of Organometallic Chemistry 592 (1999) 296–305
297
work we have generated a range of species in which the
PR2H or PRH2 ligands behave as neutral two-electron
donors. We report here the synthesis and spectroscopic
(including 1H-, 13C{1H}-, 31P{1H}- and 95Mo-NMR)
characterisation of a series of di- and tri-substituted
complexes fac-[M(CO)3L3] (M=Mo or W; L=PPh2H
or PPhH2), cis-[M(CO)4L2] (M=Cr, Mo or W; L=
PPh2H, PCy2H or PPhH2) and cis-[Mo(CO)4(L–L)]
(L–L=PhHPCH2CH2PHPh, PhHPCH2CH2CH2PHPh
or o-C6H4(PH2)2). Reaction of [M(CO)6] with excess
phosphine in ethanolic NaBH4 produces the fac or the
cis species, depending upon the nature of the phos-
phine, while the cis species form by substitution of nbd
or TMPA from the appropriate tetracarbonyl precursor
species. Single-crystal X-ray structure determinations
on fac-[Mo(CO)3(PPhH2)3], fac-[W(CO)3(PPh2H)3], cis-
[Cr(CO)4(PPh2H)2], cis-[Mo(CO)4(PPhH2)2] and cis-
[W(CO)4(PPh2H)2] are also described and trends in the
data are discussed. The preparations of [Cr(CO)4-
(PPhH2)2], [Mo(CO)4(PPhH2)2], [Mo(CO)4(PPh2H)2]
and [Mo(CO)3(PPh2H)3] have been reported previously,
however, since this was in the 1960s and early 1970s,
their spectroscopic and structural characterisation were
rather limited [10], although the crystal structure of
fac-[Mo(CO)3(PPh2H)3] · 0.25hexane has been reported
[11]. The preparation and spectroscopic characterisa-
tion of the complexes cis-[Mo(CO)4(PhHPCH2-
CH2PHPh)] and cis-[Mo(CO)4(PhHPCH2CH2CH2-
PHPh)] have also been described [12]. We have resyn-
thesised these disecondary phosphine complexes to ob-
tain 95Mo-NMR data and to allow comparisons with
the other species.
5–6 ppm due to PꢀH functions. Together with micro-
analytical data, these results indicate the formulation
fac-[M(CO)3L3] for the products. Chatt and co-workers
have used borohydride to activate the CO ligands in the
preparation of a number of tertiary phosphine com-
plexes of Mo– and W–tetracarbonyls [13], however,
with PPh2H and PPhH2 we did not observe any com-
pounds with lower degrees of carbonyl substitution
under these reaction conditions. Similar reaction with
PCy2H does not yield fac-[M(CO)3(PCy2H)3], but in-
stead gives only cis-[M(CO)4(PCy2H)2]. It is unlikely
that this is due to steric constraints alone since we have
recently [5] prepared fac-[Mn(CO)3(PCy2H)3]+, which
incorporates three mutually fac-PCy2H ligands. The
compound fac-[Mo(CO)3(PPh2H)3] has been previously
synthesised by the reaction of [Mo(CO)3(C7H8)]
(C7H8=cycloheptatriene) and PPh2H in refluxing
toluene and our spectroscopic data are consistent with
those reported [10].
The cis-disubstituted species [M(CO)4L2] (M=Cr,
Mo, W; L=PPh2H, PCy2H, PPhH2) are formed by
treatment of cis-[M(CO)4(nbd)] (M=Cr, Mo; nbd=
norbornadiene) or cis-[W(CO)4(TMPA)] (TMPA=
Me2N(CH2)3NMe2) with two molar equivalents of L in
CH2Cl2 solution. While cis-[M(CO)4(piperidine)2] (M=
Mo or W) react similarly to yield the desired species,
typically we found that poorer yields were obtained
from this route. cis-[Mo(CO)4(L–L)] (L–L=
PhHPCH2CH2PHPh, PhHPCH2CH2CH2PHPh or o-
C6H4(PH2)2) were prepared similarly from [Mo(CO)4-
(nbd)]
and
L–L.
[Mo(CO)4(PhHPCH2CH2-
PHPh)] and [Mo(CO)4(PhHPCH2CH2CH2PHPh)] were
prepared previously via the reaction of [Mo(CO)6] and
the phosphine in refluxing diglyme [12].
2. Results and discussion
Mass spectra were obtained either by FAB or APCI,
and show peaks with the correct isotopic distribution
for [M(CO)4L2] (or [Mo(CO)4(L–L)]) as well as frag-
ment ions consistent with loss of CO or L (or L–L).
Solution IR spectroscopy shows (Table 1) four w(CO)
stretching vibrations consistent with the cis-disubsti-
tuted species (theory 2a1+b1+b2) and our data are
consistent with the literature data for those compounds
previously reported [10]. There is also evidence for
coordinated L and PꢀH functions from IR spec-
Reaction of [M(CO)6] with 4.5 molar equivalents of
L (L=PPh2H or PPhH2) in degassed EtOH solution in
the presence of an excess of NaBH4, gives the com-
plexes fac-[M(CO)3L3] in moderate yield as pale yellow/
fawn coloured solids. The reactions were followed by
solution IR spectroscopy, and were considered to be
complete when the CO bands associated with the hex-
acarbonyl metal precursor had completely disappeared.
The fast-atom bombardment mass spectra (FAB MS)
of the isolated products show highest mass peaks with
the correct isotopic distributions corresponding to
[M(CO)3L3]+. Other peaks arising from fragmentation
products generated via sequential loss of CO or L are
also observed. As expected for fac-trisubstituted spe-
cies, the IR spectra show two strong CO stretching
vibrations (theory a1+e), as well as peaks due to
coordinated ligand. Evidence for retention of the P-
bound protons comes from the appearance of a weak
peak at ca. 2300 cm−1 (wPH), and 1H-NMR spec-
troscopy which reveals a very broad multiplet around
1
troscopy (KBr disk). The H-NMR spectra confirm the
presence of the primary or secondary phosphines and
show a broad multiplet around 5–6 ppm due to the
PꢀH protons.
31P{1H}-, 95Mo- and 13C{1H}-NMR spectroscopic
data were recorded for the compounds. The 13C{1H}-
NMR spectra show resonances associated with the Ph
or Cy groups on the phosphine ligands. In addition we
observe 31P coupling to the CO resonances. For the
fac-species l(CO) appears as a doublet of triplets due
to coupling to the magnetically non-equivalent phos-

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T. Campbell et al. / Journal of Organometallic Chemistry 592 (1999) 296–305
[12]. For the tungsten complexes we observed 183W
satellites on all of the resonances (183W: I=1/2, 14.4%).
For all of the Group 6 species studied the 1H-coupled
31P-NMR spectra reveal either broad doublets or broad
triplets due to coupling between the 31P and the directly
bound 1H nuclei, 1JPH ca. 320 Hz (there is also evidence
for coupling to the Ph and Cy ring protons).
phines, while for the cis compounds two CO environ-
ments are observed, a triplet corresponding to the CO
ligands cis to the phosphines and a doublet of doublets
due to the CO ligands trans to phosphine. l(CO) for
the former lies to a lower frequency. The cis 13C–31P
couplings (ca. 8–15 Hz) are consistently smaller than
the trans couplings (ca. 20–30 Hz).
95Mo-NMR spectra for the fac-species each show a
quartet consistent with coupling to three equivalent P
nuclei, while the cis-species show a triplet. l(95Mo) for
the substituted complexes typically lies to a higher
frequency than that for [Mo(CO)6] (−1856 [15]), with
the trisubstituted species at higher frequencies than the
disubstituted derivatives, consistent with the trends in
the literature [16]. The resonance for the disecondary
and diprimary phosphine complexes which involve five-
membered chelate rings, lie to low frequency compared
with the other Mo species studied, (including the
PhHPCH2CH2CH2PHPh complex which involves a six-
membered chelate ring), and rather closer to [Mo(CO)6]
itself. However, the 31P coupling establishes unequivo-
cally the assignments for these resonances. For
[Mo(CO)4(PhHPCH2CH2PHPh)] two triplets are ob-
served due to the meso and DL stereoisomers,
The 31P{1H}-NMR spectra each show a singlet reso-
nance (except the disecondary phosphine complexes —
see below) indicative of equivalent P environments and
these occur to high frequency of the uncoordinated
phosphine. There is a shift of l(31P) to high frequency
with an increasing degree of substitution at the metal
centre, and a shift to low frequency from Cr“Mo“
W. For the molybdenum species coupling to 95/97Mo
(95Mo: I=5/2. 15.7%, Q=0.12×10−28 m2; 97Mo: I=
5/2, 9.5%, Q=1.1×10−28 m2) is clearly evident for the
fac-species, giving a six-line satellite pattern, suggesting
that the electric field gradient at Mo in these C36 species
is very small. In contrast, no 95/97Mo coupling is ob-
served in the 31P{1H}-NMR spectra of the cis-disubsti-
tuted Mo species (C26). For the diphosphine species we
observe the expected trend in l(31P) with chelate ring
size [14].
Two stereoisomers are possible for the disecondary
phosphine complexes (meso and DL), and hence we
observe these by NMR spectroscopy. For [Mo(CO)4-
(PhHPCH2CH2PHPh)] we observe both stereoisomers
in ca. 1:1 ratio, l(31P) 18.5, 21.0, while for [Mo(CO)4-
(PhHPCH2CH2CH2PHPh)] one of the stereoisomers
(meso) dominates (l(31P) −6.9, \95%), consistent
with the ratio of the meso:DL forms in the free diphos-
phine. The 31P-NMR data for these disecondary phos-
phine complexes compare well with the literature data
1
l(95Mo)= −1847, JMoP=128 Hz and l(95Mo)= −
1
1860, JMoP=123 Hz, while for [Mo(CO)4(PhHPCH2-
CH2CH2PHPh)] we observe one triplet at −1779 ppm
(1JMoP=125 Hz), assigned to the meso isomer. The
coupling constants are comparable with those reported
for other Mo(0) phosphines [16].
In order to confirm the stereochemistries at the metal
centres and to establish structural trends, single-crystal
X-ray structure analyses were undertaken on fac-
[Mo(CO)3(PPhH2)3], fac-[W(CO)3(PPh2H)3], cis-[Cr-
(CO)4(PPh2H)2], cis-[Mo(CO)4(PPhH2)2] and cis-
[W(CO)4(PPh2H)2]. The crystal structure of [Mo(CO)3-
Table 1
31P{1H}- and 95Mo-NMR and IR spectroscopic data a
Compound
l
31P (ppm)
l
95Mo (ppm)
JMP (Hz) b
wCO (cm−1
)
cis-[Cr(CO)4(PPh2H)2]
cis-[Cr(CO)4(PPhH2)2]
cis-[Cr(CO)4(PCy2H)2]
+42.3
−27.5
+53.4
+22.0
−53.5
+14.5
−60.5
+25.0
18.5, 21.0
−6.9
2014, 1919sh, 1901, 1886sh
2019, 1923sh, 1907, 1893sh
2001, 1901sh, 1883, 1866sh
1947, 1855
fac-[Mo(CO)3(PPh2H)3]
fac-[Mo(CO)3(PPhH2)3]
cis-[Mo(CO)4(PPh2H)2]
cis-[Mo(CO)4(PPhH2)2]
cis-[Mo(CO)4(PCy2H)2]
cis-[Mo(CO)4(PhHPCH2CH2PHPh)]
cis-[Mo(CO)4(PhHPCH2CH2CH2PHPh)]
cis-[Mo(CO)4{o-C6H4(PH2)2}]
fac-[W(CO)3(PPh2H)3]
−1639q
−1702q
−1724t
−1769t
−1810t
−1847t, −1860t
−1779t
105
121
130
124
132
128, 123
125
120
217
1957, 1866
2026, 1926sh, 1914, 1892sh
2030, 1930sh, 1918, 1897sh
2014, 1909sh, 1894, 1872sh
2024, 1926sh, 1908, 1891sh
2023, 1924sh, 1903, 1888sh
2032, 1935sh, 1919, 1903sh
1942, 1851
−44.1
+4.3
−1891t
fac-[W(CO)3(PPhH2)3]
cis-[W(CO)4(PPh2H)2]
cis-[W(CO)4(PPhH2)2]
cis-[W(CO)4(PCy2H)2]
−72.0
−4.6
−80.9
+8.6
209
227
200
214
1951, 1858
2022, 1917sh, 1903, 1885sh
2026, 1907sh, 1875, 1864sh
2010, 1904sh, 1883, 1860sh
a Spectra were recorded at 300 K in CDCl3 solution.
b Refers to 1J(95Mo–31P) or 1J(185W–31P) as appropriate.

T. Campbell et al. / Journal of Organometallic Chemistry 592 (1999) 296–305
299
geometry and confirming the structure deduced spectro-
scopically in solution. The MꢀCtrans CO bond distances
in these compounds are longer than those trans to P, a
trend observed previously for cis-[M(CO)4(PR3)2] [17].
Importantly, in a number of these structures (see
Section 3) the integrity of the PꢀH functions was confi-
rmed crystallographically with the H atoms being lo-
cated from the difference map, thus these primary and
secondary phosphines behave as neutral two-electron
donors to Group 6 metal carbonyls.
Comparing the data for [Mo(CO)3(PPhH2)3] with
that for [Mo(CO)4(PPhH2)2] shows that the MoꢀP bond
lengths are virtually insensitive to the degree of substi-
tution at Mo. This is also true for the tungsten–
diphenylphosphine derivatives. The MoꢀP distances
and the bond angles around Mo in the previously
characterised fac-[Mo(CO)3(PPh2H)3].0.25C6H14 (Moꢀ
Fig. 1. View of the structure of fac-[Mo(CO)3(PPhH2)3] with number-
ing scheme adopted. Ellipsoids are drawn at 40% probability.
Table 2
,
Selected bond lengths (A) and bond angles (°) for fac-[Mo(CO)3-
(PPhH2)3]
Bond lengths
MoꢀP(1)
MoꢀP(3)
MoꢀC(2)
2.501(3)
2.500(3)
1.972(10)
MoꢀP(2)
MoꢀC(1)
MoꢀC(3)
2.493(3)
1.99(l)
1.97(1)
Bond angles
P(1)ꢀMoꢀP(2)
P(1)ꢀMoꢀC(1)
P(1)ꢀMoꢀC(3)
P(2)ꢀMoꢀC(1)
P(2)ꢀMoꢀC(3)
P(3)ꢀMoꢀC(2)
C(1)ꢀMoꢀC(2)
C(2)ꢀMoꢀC(3)
87.35(9)
92.2(3)
92.9(3)
89.5(3)
179.2(3))
91.4(3)
89.5(4)
92.1(4)
P(1)ꢀMoꢀP(3)
P(1)ꢀMoꢀC(2)
P(2)ꢀMoꢀP(3)
P(2)ꢀMoꢀC(2)
P(3)ꢀMoꢀC(1)
P(3)ꢀMoꢀC(3)
C(1)ꢀMoꢀC(3)
86.78(9)
174.8(3)
90.08(10)
87.8(3)
178.9(2)
90.7(3)
89.8(4)
Fig. 2. View of the structure of fac-[W(CO)3(PPh2H)3)] with number-
ing scheme adopted. Ellipsoids are drawn at 40% probability.
(PPhH2)3] shows a discrete neutral molecule in the
asymmetric unit, (Fig. 1, Table 2) with the primary
phosphine ligands in a fac arrangement giving a dis-
torted octahedral geometry at Mo, MoꢀP=2.493(3)–
Table 3
,
Selected bond lengths (A) and bond angles (°) for fac-[W(CO)3-
(PPh2H)3]
,
2.501(3), MoꢀC=1.97(1)–1.99(1) A. The cis angles
around the metal centre lie in the range 86.78(9)–
92.9(3)°. The crystal structure of [W(CO)3(PPh2H)3]
also confirms the fac arrangement of the phosphine
ligands (Fig. 2, Table 3) giving a very similar overall
geometry, with WꢀP=2.490(4)–2.504(3), WꢀC=
Bond lengths
W(1)ꢀP(1)
W(1)ꢀP(3)
W(1)ꢀC(2)
2.490(4)
2.493(3)
1.97(1)
W(1)ꢀP(2)
W(1)ꢀC(1)
W(1)ꢀC(3)
2.504(3)
1.95(1)
1.97(1)
Bond angles
,
1.95(1)–1.97(1) A. The MꢀP and MꢀC bond lengths in
P(1)ꢀW(1)ꢀP(2)
P(1)ꢀW(1)ꢀC(1)
P(1)ꢀW(1)ꢀC(3)
P(2)ꢀW(1)ꢀC(1)
P(2)ꢀW(1)ꢀC(3)
P(3)ꢀW(1)ꢀC(2)
C(1)ꢀW(1)ꢀC(2)
C(2)ꢀW(1)ꢀC(3)
87.5(1)
91.2(4)
178.6(4)
92.4(4)
93.0(4)
91.6(4)
89.4(5)
86.1(5)
P(1)ꢀW(1)ꢀP(3)
P(1)ꢀW(1)ꢀC(2)
P(2)ꢀW(1)ꢀP(3)
P(2)ꢀW(1)ꢀC(2)
P(3)ꢀW(1)ꢀC(1)
P(3)ꢀW(1)ꢀC(3)
C(1)ꢀW(1)ꢀC(3)
90.9(1)
93.5(4)
86.6(1)
177.9(3)
177.7(4)
90.5(4)
87.4(5)
these species are not significantly different, reflecting
the similarity of the Mo(0) and W(0) radii.
The crystal structures of the disubstituted species
[Cr(CO)4(PPh2H)2] (Fig. 3, Table 4), [Mo(CO)4-
(PPhH2)2] (Fig. 4, Table 5) and [W(CO)4(PPh2H)2] (Fig.
5, Table 6) each confirm a cis-disubstituted arrange-
ment at the metal centre, giving a distorted octahedral

300
T. Campbell et al. / Journal of Organometallic Chemistry 592 (1999) 296–305
Elmer 983 spectrometer over the range 4000–200
cm−1. Mass spectra were run by electron impact or
FAB using 3-NOBA (3-nitrobenzyl alcohol) as matrix
on a VG Analytical 70-250-SE Normal Geometry Dou-
ble Focusing Mass Spectrometer or by APCI using a
1
VG Biotech platform. H-NMR spectra were recorded
in CDCl3 using
a Bruker AM300 spectrometer.
31P{1H}-, 95Mo{1H}- and 13C{1H}-NMR spectra were
recorded in CH2Cl2 containing ca. 10–15% CDCl3 us-
ing a Bruker AM360 spectrometer operating at 145.8,
23.48 or 90.55 MHz, respectively, and are referenced to
85% H3PO4, aqueous Na2[MoO4] and Me4Si, respec-
tively (l=0). [Cr(acac)3] was added to the NMR solu-
Fig. 3. View of the structure of cis-[Cr(CO)4(PPh2H)2] with number-
ing scheme adopted. Ellipsoids are drawn at 40% probability.
Table 4
,
Selected bond lengths (A) and bond angles (°) for cis-
[Cr(CO)4(PPh2H)3]
Bond lengths
Cr(1)ꢀP(1)
Cr(1)ꢀC(1)
Cr(1)ꢀC(3)
2.359(2)
1.867(4)
1.897(4)
Cr(1)ꢀP(2)
Cr(1)ꢀC(2)
Cr(1)ꢀC(4)
2.347(2)
1.857(5)
1.891(4)
Bond angles
P(1)ꢀCr(1)ꢀP(2)
P(1)ꢀCr(1)ꢀC(2)
P(1)ꢀCr(1)ꢀC(4)
P(2)ꢀCr(1)ꢀC(2)
P(2)ꢀCr(1)ꢀC(4)
C(1)ꢀCr(1)ꢀC(3)
C(2)ꢀCr(1)ꢀC(3)
C(3)ꢀCr(1)ꢀC(4)
91.98(9) P(1)ꢀCr(1)ꢀC(1)
177.9(1)
87.9(1)
89.5(1)
89.2(1)
87.4(2)
90.6(2)
93.6(2)
91.1(2)
90.9(1)
176.7(1)
85.2(1)
90.7(2)
92.1(2)
174.2(2)
P(1)ꢀCr(1)ꢀC(3)
P(2)ꢀCr(1)ꢀC(1)
P(2)ꢀCr(1)ꢀC(3)
C(1)ꢀCr(1)ꢀC(2)
C(1)ꢀCr(1)ꢀC(4)
C(2)ꢀCr(1)ꢀC(4)
Fig. 4. View of the structure of cis-[Mo(CO)4(PPhH2)2] with number-
ing scheme adopted. Ellipsoids are drawn at 40% probability. Only
one of the two equally probable orientations for the disordered
phenyl rings is shown.
Table 5
,
Selected bond lengths (A) and bond angles (°) for fac-
[Mo(CO)4(PPhH2)2]
,
P=2.490(3)–2.506(4), MoꢀC=1.930(12)–1.940(13) A,
BPꢀMoꢀP=85.2(1)–87.9(1)°) [11] compare closely
with the bond length and angle distributions for fac-
[Mo(CO)3(PPhH2)3] reported here, indicating that the
differing cone angles of the phosphines in these species
have little effect upon the geometry at Mo.
Bond lengths
Mo(1)ꢀP(1)
Mo(1)ꢀC(1)
Mo(1)ꢀC(2)
2.508(3)
2.06(1)
1.98(1)
Mo(1)ꢀP(1)
Mo(1)ꢀC(1)
Mo(1)ꢀC(2)
2.508(3)
2.06(1)
1.98(1)
Bond angles
P(1)ꢀMo(1)ꢀP(1)
P(1)ꢀMo(1)ꢀC(1)
P(1)ꢀMo(1)ꢀC(2)
P(1)ꢀMo(1)ꢀC(1)
P(1)ꢀMo(1)ꢀC(2)
C(1)ꢀMo(1)ꢀC(2)
C(1)ꢀMo(1)ꢀC(2)
C(2)ꢀMo(1)ꢀC(2)
87.9(1)
89.5(3)
178.6(3)
89.8(3)
93.5(3)
90.2(5)
90.6(4)
85.2(6)
P(1)ꢀMo(1)ꢀC(1)
P(1)ꢀMo(1)ꢀC(2)
P(1)ꢀMo(1)ꢀC(1)
P(1)ꢀMo(1)ꢀC(2)
C(1)ꢀMo(1)ꢀC(1)
C(1)ꢀMo(1)ꢀC(2)
C(1)ꢀMo(1)ꢀC(2)
89.8(3)
93.5(3)
89.5(3)
178.6(3)
179.0(6)
90.6(4)
90.2(5)
3. Experimental
Infrared spectra were measured in CH2Cl2 solution
using a Perkin–Elmer 1600 FTIR over the range 2200–
1700 cm−1 or as KBr or CsI discs using a Perkin–

T. Campbell et al. / Journal of Organometallic Chemistry 592 (1999) 296–305
301
yellow precipitate. This solid was filtered and washed
with heptane and dried in vacuo. The compounds was
recrystallised from CH2Cl2–diethyl ether. Yield 1.79 g,
91%. Required for [C39H33MoO3P3]: C, 63.4, H, 4.5.
Found: C, 63.9; H, 4.8%. FAB MS (3-NOBA matrix):
Found m/z=526, 470, 313, 284; Calc. for
[98Mo(CO)2(PPh2H)2]+ m/z=526, [98Mo(PPh2H)2]+ m/
z=469, [98Mo(CO)(PPh2H)2]+ m/z=313; [98Mo(PPh2-
1
H)]+ m/z=283. H-NMR: l 7.43–7.17 (m, Ph, 10H),
5.55 (m, PH, 1H). 13C{1H}-NMR: l 219.0 (dt, CO),
128–135 (Ph).
3.1.2. fac-[Mo(CO)3(PPhH2)3]
Pale yellow solid. Yield 65%. Required for
[C21H21MoO3P3]: C, 49.4; H, 4.2. Found: C, 50.0, H,
1
4.6%. H-NMR: l 7.4–7.1 (m, Ph, 5H), 5.3 (m, PH,
2H). 13C{1H}-NMR: l 217.9 (dt, CO), 128–133 (Ph).
3.1.3. fac-[W(CO)3(PPh2H)3]
Fawn
solid.
Yield
23%.
Required
for
Fig. 5. View of the structure of cis-[W(CO)4(PPh2H)2] with number-
ing scheme adopted. Ellipsoids are drawn at 40% probability.
[C39H33WO3P3] · CHCl3: C, 50.8; H, 3.6. Found: C,
50.7; H, 5.2%. FAB MS (3-NOBA matrix): Found
m/z=826, 797, 769, 610, 554, 454, 398, 368; Calc. for
Table 6
[
183W(CO)3(PPh2H)3]+ m/z=825,
[
183W(CO)2(PPh2-
,
Selected bond lengths (A) and bond angles (°) for fac-
[W(CO)4(PPh2H)2]
H)3]+ m/z=797, 183W(CO)(PPh2H)3]+ m/z=769;
[
[
183W(CO)2(PPh2H)2]+ m/z=609; [183W(PPh2H)2]+ m/
Bond lengths
z=553; [183W(CO)3(PPh2H)]+ m/z=453; [183W(CO)-
W(1)ꢀP(1)
W(1)ꢀC(1)
W(1)ꢀC(3)
2.467(4)
2.01(2)
2.03(2)
W(1)ꢀP(2)
W(1)ꢀC(2)
W(1)ꢀC(4)
2.513(4)
2.02(2)
2.03(2)
(PPh2H)]+ m/z=397; [183W(PPh2H)]+ m/z=367. H-
1
NMR: l 7.5–7.2 (m, Ph, 10H), 5.8 (m, PH, 1H).
13C{1H}-NMR: l 211.3 (dt, CO), 128–135 (Ph).
Bond angles
P(1)ꢀW(1)ꢀP(2)
P(1)ꢀW(1)ꢀC(2)
P(1)ꢀW(1)ꢀC(4)
P(2)ꢀW(1)ꢀC(2)
P(2)ꢀW(1)ꢀC(4)
C(1)ꢀW(1)ꢀC(3)
C(2)ꢀW(1)ꢀC(3)
C(3)ꢀW(1)ꢀC(4)
89.6(1)
91.0(5)
87.0(5)
83.4(5)
89.9(5)
87.3(6)
95.2(6)
91.6(7)
P(1)ꢀW(1)ꢀC(1)
P(1)ꢀW(1)ꢀC(3)
P(2)ꢀW(1)ꢀC(1)
P(2)ꢀW(1)ꢀC(3)
C(1)ꢀW(1)ꢀC(2)
C(1)ꢀW(1)ꢀC(4)
C(2)ꢀW(1)ꢀC(4)
177.3(5)
92.5(4)
90.7(5)
177.5(5)
91.7(6)
90.3(7)
173.0(7)
3.1.4. fac-[W(CO)3(PPhH2)3]
Fawn solid. Yield 33%. Required for [C21H21WO3P3]:
C, 42.1; H, 3.5%. Found: C, 42.1, H, 3.8%. Electro-
spray MS: Found m/z=598; Calc. for [183W(CO)3-
1
(PPhH2)3]+ m/z=597. H-NMR: l 7.43–7.13 (m, Ph,
5H), 5.83 (m, PH, 2H). 13C{1H}-NMR: l 209.1 (dt,
CO), 126–134 (Ph).
tions prior to recording 13C{1H}-NMR spectra and a
pulse delay of 2 s was introduced to accommodate the
long relaxation times. Microanalyses were performed
by the University of Strathclyde microanalytical service.
[Mo(CO)4(nbd)], [Cr(CO)4(nbd) and [W(CO)4(TMPA]
were prepared according to literature procedures
[18,19].
3.1.5. cis-[Cr(CO)4(PPh2H)2]
[Cr(CO)4(nbd)] (0.15 g, 0.586 mmol) was dissolved in
stirring, degassed toluene (50 ml). PPh2H (0.218 g,
1.172 mmol) was dissolved in degassed toluene (10 ml)
and added dropwise to the solution under a dinitrogen
atmosphere. The reaction mixture was stirred and
heated to approximately 40°C for 24 h, or until solution
IR studies showed the absence of bands associated with
the starting material. The solvent was removed in vacuo
and the resulting residue redissolved in the minimum
volume of CH2Cl2. Cold hexane was added (10 ml) and
the solution stored at −15°C. The resulting pale yellow
crystalline solid was filtered and dried in vacuo.
Yield=0.242 g, 77%. Required for [C28H22CrO4P2.
CH2Cl2]: C, 56.0; H, 3.9. Found: C, 56.1; H,
3.8%. APCI MS (MeCN): Found m/z=548, 507, 424;
Calc. for [52Cr(CO)4(PPh2H)2] · MeCN+ m/z=548,
3.1. Preparations
3.1.1. fac-[Mo(CO)3(PPh2H)3]
To a degassed solution of [Mo(CO)6] (0.75 g, 2.61
mmol) and NaBH4 (0.45 g, 11.7 mmol) in EtOH (70
cm3), PPh2H (1.5 g, 7.8 mmol) in EtOH (20 cm3) were
added dropwise over ca. 20 min. The resulting mixture
was refluxed for 19 h. After cooling, the reaction vol-
ume was reduced to ca. 20 cm3 in vacuo to give a pale

302
T. Campbell et al. / Journal of Organometallic Chemistry 592 (1999) 296–305
[52Cr(CO)3(PPh2H)2]+ m/z=507, [52Cr(PPh2H)2]+ m/
3.1.10. cis-[Mo(CO)4(PPhH2)2]
1
z=424. H-NMR: l 7.2–7.6 (m, Ph, 10H), 6.1 (m, PH,
Pale yellow solid. Yield=60%. Required for
[C16H14MoO4P2]: C, 44.9; H, 3.3. Found: C, 44.8; H,
3.3%. APCI MS (MeCN): Found m/z=431, 401, 373,
291; Calc. for [98Mo(CO)4(PPhH2)2]+ m/z=430,
1H). 13C{1H}-NMR: l 226.5 (dd, CO), 220.0 (t, CO),
128.7–133.6 (Ph).
3.1.6. cis-[Cr(CO)4(PCy2H)2]
[98Mo(CO)3(PPhH2)2]+
m/z=402,
[98Mo(CO)2-
Pale yellow solid. Yield=68%. Required for
[C28H46CrO4P2]: C, 60.0; H, 8.2. Found: C, 60.5; H,
8.7%. APCI MS (MeCN): Found m/z=561, 279; Calc.
for [52Cr(CO)4(PCy2H)2]+ m/z=561, [52Cr(CO)-
(PPhH2)2]+ m/z=374, [98Mo(CO)3(PPhH2)]+ m/z=
1
292. H-NMR: l 7.3–7.6 (m, Ph, 5H), 5.3 (m, PH, 2H).
13C{1H}-NMR: l 213.4 (dd, CO), 208.0 (t, CO), 128.8–
132.9 (Ph).
1
(PCy2H)]+ m/z=279. H-NMR: l 4.7 (m, PH, 1H),
1.2–2.2 (m, Cy, 22H). 13C{1H}-NMR: l 227.5 (dd, CO)
222.3 (t, CO), 13.6–35.7 (Cy).
3.1.11. cis-[Mo(CO)4(PhHP(CH2)2PHPh)]
Fawn solid. Yield=86%. Required for [C18H16-
MoO4P2]: C, 44.9; H, 3.3. Found: C, 44.8; H, 3.3%.
APCI MS (MeCN): Found m/z=399; Calc. for
[98Mo(CO)2(PhHPCH2CH2PHPh)]+ m/z=400. 1H-
NMR: l 7.3–7.6 (m, Ph, 10H), 5.5 (m, PH, 2H), 2.5 (m,
CH2, 4H).
3.1.7. cis-[Cr(CO)4(PPhH2)2]
Pale yellow solid. Yield=88%. Required for
[C16H14CrO4P2]: C, 50.0; H, 3.6. Found: C, 49.8; H,
3.8%. APCI MS (MeCN): Found m/z=384, 272; Calc.
for [52Cr(CO)4(PPh2H)2]+ m/z=384, [52Cr(CO)4-
(PPh2H)]+ m/z=272. 1H-NMR: l 7.4–7.6 (m, Ph,
5H), 5.3 (m, PH, 2H). 13C{1H}-NMR: l 225.3 (dd, CO),
219.4 (t, CO), 127.4–132.2 (Ph).
3.1.12. cis-[Mo(CO)4(PhHP(CH2)3PHPh]
Fawn
solid.
Yield=86%.
Required
for
[C19H18MoO4P2]: C, 44.9; H, 3.3. Found: C, 44.8; H,
3.3%. APCI MS (MeCN): Found m/z=469, 441, 413;
Calc. for [98Mo(CO)4(PhHPCH2CH2CH2PHPh)]+ m/
z=470, [98Mo(CO)3(PhHPCH2CH2CH2PHPh)]+ m/
3.1.8. cis-[Mo(CO)4(PPh2H)2]
[Mo(CO)4(nbd)] (0.100 g, 0.333 mmol) was dissolved
in stirring, degassed toluene (50 ml). PPh2H (0.124 g,
0.666 mmol) was dissolved in degassed toluene (10 ml)
and added dropwise to the solution under a dinitrogen
atmosphere. The reaction mixture was stirred in the
absence of light for 24 h, or until solution IR studies
showed the absence of bands associated with the start-
ing material. The solvent was removed in vacuo and the
resulting residue redissolved in the minimum volume of
CH2Cl2. Cold hexane was added (10 ml) and the solu-
tion stored at −15°C. The resulting crystalline solid
was filtered and dried in vacuo. Yield=0.141 g, 73%.
Pale yellow solid. Required for [C28H22MoO4P2]: C,
57.9; H, 3.8. Found: C, 57.5; H, 3.7%. FAB MS
(3-NOBA matrix): Found m/z=582, 554, 526, 470,
284; Calc. for [98Mo(CO)4(PPh2H)2]+ m/z=582,
z=442,
[98Mo(CO)2(PhHPCH2CH2CH2PHPh)]+
1
m/z=414. H-NMR: l 7.3–7.7 (m, Ph, 10H), 5.6 (m,
PH, 2H), 2.6 (br m, CH2, 6H).
3.1.13. cis-[Mo(CO)4(o-C6H4(PH2)2)]
Fawn
solid.
Yield=86%.
Required
for
[C10H8MoO4P2].0.5 CH2Cl2: C, 32.1; H, 2.3. Found: C,
32.1; H, 2.0%. APCI MS (MeCN): Found m/z=348,
323, 292; Calc. for [98Mo(CO)4(o-C6H4(PH2)2)]+ m/z=
352, [98Mo(CO)3(o-C6H4(PH2)2)]+ m/z=324, [98Mo-
(CO)2(o-C6H4(PH2)2)]+ m/z=296. 1H-NMR: l 7.5–8.0
(m, o-C6H4, 4H), 5.6 (m, PH, 4H). 13C{1H}-NMR: l
215.1 (dd, CO), 207.4 (t, CO), 129.9–137.9 (Ph).
[98Mo(CO)3(PPh2H)2]+
m/z=554,
[98Mo(CO)2-
3.1.14. cis-[W(CO)4(PPh2H)2]
(PPh2H)2]+ m/z=526, [98Mo(PPh2H)2]+ m/z=470,
[98Mo(PPh2H)]+ m/z=284. 1H-NMR: l 7.2–8.0 (m,
Ph, 10H), 6.0 (m, PH, 1H). 13C{1H}-NMR: l 215.1 (dd,
CO), 209.1 (t, CO), 126.8–135.9 (Ph).
[W(CO)4(TMPA)], (0.100 g, 0.233 mmol), was dis-
solved in stirring degassed toluene (50 ml). PPh2H
(0.087 g, 0.466 mmol) was dissolved in degassed toluene
(10 ml) and added dropwise to the solution under a
dinitrogen atmosphere. The reaction mixture was
stirred and heated to approximately 60°C for 24 h, or
until solution IR studies showed the absence of bands
associated with the starting material. The solvent was
removed in vacuo and the resulting residue redissolved
in the minimum volume of CH2Cl2. Cold hexane was
added (10 ml) and the solution stored at −15°C. The
resulting fawn coloured crystalline solid was filtered
and dried in vacuo. Yield=0.100 g, 64%. Required for
[C28H22WO4P2]: C, 50.4; H, 3.6. Found: C, 49.9; H,
3.3%. FAB MS (3-NOBA matrix): Found m/z=668,
3.1.9. cis-[Mo(CO)4(PCy2H)2]
Pale yellow solid. Yield=62%. Required for
[C28H46MoO4P2]: C, 55.4; H, 7.6. Found: C, 55.2; H,
8.1%. FAB MS (3-NOBA matrix): Found m/z=606,
578, 548, 518; Calc. for [98Mo(CO)4(PCy2H)2]+ m/z=
606, [98Mo(CO)3(PCy2H)2]+ m/z=578, [98Mo(CO)2-
(PCy2H)2]+ m/z=548, [98Mo(CO)(PCy2H)2]+ m/z=
518. 1H-NMR: l 4.8 (m, PH, 1H), 1.1–2.3 (m, Cy,
22H). 13C{1H}-NMR: l 216.3 (dd, CO), 211.7 (t, CO),
24.5–35.8 (Cy).

T. Campbell et al. / Journal of Organometallic Chemistry 592 (1999) 296–305
303
639, 612, 554, 454, 426, 398; Calc. for
(PPh)2]+ m/z=428, 184W(PPh)2]+ m/z=400. 1H-
[
NMR: l 7.2–7.5 (m, Ph, 5H), 5.5 (m, PH, 2H).
13C{1H}-NMR: l 211.9 (dd, CO), 205.6 (t, CO), 125.2–
130.1 (Ph).
[
184W(CO)4(PPh2H)2]+
m/z=668,
[
184W(CO)3-
(PPh2H)2]+ m/z=639, [184W(CO)2(PPh2H)2]+ m/z=
612, [184W(PPh2H)2]+ m/z=554, [184W(CO)3(PPh2H)]+
m/z=454,
[ [
184W(CO)2(PPh2H)]+ m/z=426, 184W-
(CO)(PPh2H)]+ m/z=398. 1H-NMR: l 7.0–7.5 (m, Ph,
10H), 6.3 (m, PH, 1H). 13C{1H}-NMR: l 205.6 (dd,
CO), 201.0 (t, CO), 126.9–135.6 (Ph).
3.2. X-ray crystallography
Details of the crystallographic data collection and
refinement parameters are given in Table 7. The crystals
were grown by vapour diffusion of diethyl ether onto
solutions of the complexes in CH2Cl2 at ca. −15°C.
Data collection used a Rigaku AFC7S four-circle dif-
fractometer equipped with an Oxford Systems open-
flow cryostat operating at 150 K, using
graphite-monochromated Mo–Ka X-radiation (u=
3.1.15. cis-[W(CO)4(PCy2H)2]
Fawn solid. Yield=54%. Required for [C28H46-
WO4P2]: C, 48.4; H, 6.6. Found: C, 47.4; H, 6.8%. FAB
MS (3-NOBA matrix): Found m/z=692, 664, 634, 604;
Calc. for [184W(CO)4(PCy2H)2]+ m/z=692,. [184W-
(CO)3(PPh2H)2]+ m/z=664, [184W(CO)2(PCy2H)2]+ m/
z=636, [184W(CO)(PCy2)2]+ m/z=606. 1H-NMR: l
4.1 (m, PH, 1H), 1.2–2.2 (m, Cy, 22H). 13C{1H}-NMR:
l 206.0 (dd, CO), 202.9 (t, CO), 23.8–36.4 (Cy).
,
0.71073 A). The data were corrected for absorption
using psi-scans (except for [Mo(CO)3(PPhH2)3] — see
below). The structures were solved by direct methods
[20] ([Mo(CO)3(PPhH2)3]) or heavy atom methods [21]
(others) and developed by iterative cycles of full matrix
least-squares and difference Fourier synthesis [22]. The
weighting scheme w−1=|2(F) gave satisfactory agree-
ment analyses.
3.1.16. cis-[W(CO)4(PPhH2)2]
Fawn
solid.
Yield=79%.
Required
for
[C16H14WO4P2]: C, 37.2; H=, 2.71. Found: C, 37.5; H,
2.86%. APCI MS (MeCN): Found m/z=438, 425, 397;
Calc. for [184W(PPh)2] · MeCN+ m/z=441, [184W(CO)-
Table 7
Crystallographic data
Complex
fac-[Mo(CO)3
fac-[W(CO)3
cis-[Cr(CO)4(PPh2H)2]
cis-[Mo(CO)4
cis-[W(CO)4
(PPhH2)3]
(PPh2H)3]
(PPhH2)2]
(PPh2H)2]
Empirical formula
Formula weight
Crystal size (mm)
Crystal system
Space group
Unit cell dimensions
C21H21MoO3P3
510.26
0.75×0.15×0.15
C39H33WO3P3
826.46
0.70×0.60×0.10
Monoclinic
P21/c
C28H22CrO4P2
536.42
0.71×0.50×0.40
Monoclinic
P21/c
C16H14MoO4P2
428.17
0.57×0.55×0.20
Orthorhombic
Pbcn
C28H22O4P2W
668.8
0.85×0.21×0.12
Monoclinic
P21/c
Triclinic
(
P1
,
a (A)
11.104(8)
16.26(1)
6.805(3)
94.11(6)
105.88(4)
108.43(7)
1104(1)
2
11.652(3)
17.410(6)
18.108(4)
90
91.76(2)
90
3671(1)
4
33.15
10.39(2)
17.438(9)
14.399(8)
90
97.62(7)
90
2586(7)
4
5.98
11.06(2)
7.82(2)
20.75(2)
90
90
90
1796(4)
4
9.21
10.443(1)
17.286(3)
14.473(3)
90
95.16(1)
90
2600.6(7)
4
46.88
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
V (A )
3
,
Z
v(Mo–Ka) (cm−1
)
8.29
Max./min. transmission
Unique observed
reflections
1.000, 0.409
3903
1.000, 0.716
6932
1.000, 0.806
4687
1.000, 0.705
1862
1.000, 0,536
4704
Rint (based on F2)
Observed reflections
With [Io\n|(Io)]
Number of parameters
0.045
2722
n=2.5
253
0.072
0.087
1.35
0.106
3749
n=3
415
0.048
0.050
1.12
0.020
3800
n=2
316
0.051
0.077
0.52
0.052
3749
n=2
316
0.075
0.128
1.74
1332
n=2
142
0.081
0.126
0.72
a
R
b
Rw
Max. residual peak
−3
,
(e A
)
a R=S(ꢀFobsꢀi−ꢀFcalcꢀi)/SꢀFobsꢀi.
2
b Rw=ꢁ[Swi(ꢀFobsꢀi−ꢀFcalcꢀi)2/SwiꢀFobsꢀi ].

304
T. Campbell et al. / Journal of Organometallic Chemistry 592 (1999) 296–305
3.2.1. [Mo(CO)3(PPhH2)3]
Data Centre, CCDC reference numbers 132792–
132796. Copies of this information may be obtained
free of charge from the Director, CCDC, 12 Union
Road, Cambridge, CB2 1EZ, UK (fax: +44-1223-336-
033; e-mail: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk).
Psi-scans did not give a satisfactory absorption cor-
rection and therefore with the model at isotropic con-
vergence the raw data were corrected for absorption
using DIFABS [23]. All non-H atoms were refined an-
isotropically while H-atoms were placed in fixed, calcu-
lated positions. Selected bond lengths and angles are
given in Table 1.
Acknowledgements
3.2.2. [W(CO)3(PPh2H)3]
All non-H atoms were refined anisotropically while
H-atoms were placed in fixed, calculated positions.
Selected bond lengths and angles are given in Table 2.
The authors thank the EPSRC and the University of
Southampton for support and Dr M. Webster for
helpful discussions on the crystallography.
3.2.3. [Cr(CO)4(PPh2H)2]
An 8.8% decrease in the intensities of the standard
reflections was observed, hence a linear decay correc-
tion was applied. All non-H atoms were refined an-
isotropically and H atoms were located from the
difference map and included but not refined. Selected
bond lengths and angles are given in Table 3.
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The crystal quality was rather poor and this is
reflected in the residuals. which are higher than nor-
mally expected. A 7.5% decrease in the intensity of the
standard reflections occurred during data collection and
a linear decay correction was therefore applied. The
molecule possesses crystallographic m symmetry, with
the Mo atom lying on the mirror plane (0, y, 1/4). Two
alternative orientations (50:50 occupancy) were iden-
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ing about C(3) and C(6) both of which are fully
occupied since they are shared by the two conforma-
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while the H atoms associated with the P atoms were
located from the difference map and included, but not
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ring were omitted from the final structure factor calcu-
lation. Selected bond lengths and angles are given in
Table 4.
3.2.5. [W(CO)4(PPh2H)2]
A 5.5% decrease in the intensities of the standard
reflections was observed, hence a linear decay correc-
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isotropically and H atoms were included in fixed,
calculated positions. Selected bond lengths and angles
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4. Supplementary material
Crystallographic data for the structural analysis has
been deposited with the Cambridge Crystallographic

T. Campbell et al. / Journal of Organometallic Chemistry 592 (1999) 296–305
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