Synthesis and reactions of the dichloro bis(3-hexyne) complex [WCl2(CO)(NCMe)(η2-EtC2Et)2]

Article abstract of DOI:10.1016/S0022-328X(01)00763-X

Reaction of [WCl₂(CO)₃(NCMe)₂] (prepared in situ by reacting [WI₂(CO)₃(NCMe)₂] with two equivalents of NaCl in acetone) with an excess of EtC₂Et in CH₂Cl₂ g

Full text of DOI:10.1016/S0022-328X(01)00763-X

Journal of Organometallic Chemistry 628 (2001) 91–98
www.elsevier.nl/locate/jorganchem
Synthesis and reactions of the dichloro bis(3-hexyne) complex
[WCl2(CO)(NCMe)(h2-EtC2Et)2]
Mutlaq Al-Jahdali, Paul K. Baker *
Department of Chemistry, Uni6ersity of Wales, Bangor, Gwynedd LL57 2UW, UK
Received 22 January 2001; accepted 27 February 2001
Abstract
Reaction of [WCl2(CO)3(NCMe)2] (prepared in situ by reacting [WI2(CO)3(NCMe)2] with two equivalents of NaCl in acetone)
with an excess of EtC2Et in CH2Cl2 gives the bis(3-hexyne) complex [WCl2(CO)(NCMe)(h2-EtC2Et)2] (1). Equimolar quantities
of 1 and L {L=NPh3, PPh3, LMo or LW [MI2(CO)3{MeC(CH2PPh2)3-P,P%}] (M=Mo, LMo; W, LW)} react in CH2Cl2 to give the
acetonitrile replaced products, [WCl2(CO)L(h2-EtC2Et)2] (2“5), in good yield. Reaction of 1 with L2 {L=PPh3, LMo, LW,
L2=Ph2P(CH2)nPPh2 (1,3,4,6), cis-Ph2PCHꢀCHPPh2} in CH2Cl2 at room temperature afforded the mono(3-hexyne) complexes,
[WCl2(CO)L2(h2-EtC2Et)] (6–13). Treatment of 1 with two equivalents of P(OR)3 {R=Et, iPr} in diethyl ether gives
[WCl2(CO){P(OR)3}2(h2-EtC2Et)] (14 and 15), respectively. Equimolar amounts of 1 and 2,2%- bipyridyl (bipy) yields the cationic
complex [WCl(CO)(bipy)(h2-EtC2Et)2]Cl (16). Reaction of equimolar quantities of 1 and NaS2CNR2·3H2O (R=Me, Et) in
CH2Cl2 at room temperature affords the mono-chloro complexes [WCl(CO)(S2CNR2)(h2-EtC2Et)2] (17 and 18). © 2001 Elsevier
Science B.V. All rights reserved.
Keywords: Tungsten; Alkyne; Carbonyl; Acetonitrile; Tertiaryphosphine
recently in 1998 [12], we described a series of mixed-
chloroiodo alkyne complexes, including the X-ray
structural characterisation of the cationic complex,
[WCl(CO)(2,2%-bipy)(h2-MeC2Me)2]I. Hitherto, far
fewer dichloro alkyne complexes of molybdenum(II)
and tungsten(II) have been reported. Templeton and
co-workers [13], Brisdon et al. [14], Nielson and co-
workers [15], and Mayr et al. [16–18] have described
some new dichloro alkyne complexes, following which,
[WCl2(CO)(L2)(h2-PhC2Ph)] (L=PMe3, PMe2Ph) [14],
[WCl2(CO)(PMe3)2(h2-PhC2NHtBu)] [15], [WCl2(CO)-
(PMe3)2(h2-PhC2R)] {R=OH, OC(O)C6H4OMe-4} [17]
and [WCl2(=CHPh)(PMe3)2(h2-PhC2Ph)] [18], have
been crystallographically characterised.
Recently [19], we have described the in situ synthesis
of the seven-coordinate dichloro-complex [WCl2(CO)3-
(NCMe)2] by the reaction of [WI2(CO)3(NCMe)2] with
two equivalents of NaCl in acetone. In this paper, we
describe the synthesis of the bis(3-hexyne) complex
[WCl2(CO)(NCMe)(h2-EtC2Et)2] (1), by the reaction of
[WCl2(CO)3(NCMe)2] (prepared in situ) with 3-hexyne.
The reactions of [WCl2(CO)(NCMe)(h2-EtC2Et)2] (1)
with neutral and anionic donor ligands is also described.
1. Introduction
Since our initial report in 1988 of the synthesis of the
dimeric mono-alkyne complexes [{M(m-I)I(CO)-
(NCMe)(h2-RC2R%)}2] (M=Mo, W; R=R%=Me, Ph,
CH2Cl; R=Ph, R%=Me, CH2OH; R=Me, R%=PhS,
p-tolS) [1] and the bis(alkyne) complexes, [{Mo(m-
I)I(CO)(h2-MeC2Me)2}2] and [MI2(CO)(NCMe)(h2-
RC2R%)2] (M=Mo, W; R=R%=Ph; R=Me, R%=Ph;
for M=W only; R=R%=Me, CH2Cl, p-tol; R=Ph,
R%=CH2OH) [2], we have developed an extensive iodo-
alkyne chemistry of molybdenum(II) and tungsten(II)
[3–9]. More recently, in 1994 [10], we have described
the synthesis and reactions with donor ligands of the
dibromo-bis(2-butyne) complex, [WBr2(CO)(NCMe)-
(h2-MeC2Me)2]. In 1989 [11], we described the synthesis
and characterisation of the mixed-halide complexes
[{W(m-Br)I(CO)(NCMe)(h2-RC2R)}2] (R=Me, Ph,
CH2Cl) and [WBrI(CO)(NCMe)(h2-RC2R)2], and very
* Corresponding author. Tel.: +44-1248-351151; fax: +44-1248-
370528.
E-mail address: chs018@bangor.ac.uk (P.K. Baker).
0022-328X/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(01)00763-X

92
M. Al-Jahdali, P.K. Baker / Journal of Organometallic Chemistry 628 (2001) 91–98
carbonyl band at 2079 cm−1, which is at higher
wavenumber compared to [WI2(CO)(NCMe)(h2-
1
EtC2Et)2] at 2056 cm−1. In view of the similar IR, H-
and 13C-NMR spectral properties of the dichloro com-
plex
1 to the related diiodo alkyne complexes
[WI2(CO)(NCR)(h2-R%C2R%)2] (R=Me, R%=Me, Ph
[2]; R=But, R%=Me [21]; R=Me, R%=Ph [22]),
which have all been crystallographically characterised,
it is very likely that the structure of 1 will be very
similar as shown in Fig. 1.
Fig. 1. Proposed structure of [WCl2(CO)(NCMe)(h2-EtC2Et)2] (1).
The room temperature 13C{1H}-NMR spectrum
(CDCl3) for complex 1 (Table 4), has alkyne contact
carbon resonances at l=162.43 and 167.50 ppm,
which from correlation of Templeton and Ward [23]
suggests that the two 3-hexyne ligands are donating a
total of six electrons to the tungsten, which also enables
complex 1 to obey the effective atomic number rule.
The rest of this paper describes the reactions of the
versatile complex, [WCl2(CO)(NCMe)(h2-EtC2Et)2] (1)
with both neutral and anionic donor ligands. These
results are summarised in Scheme 1.
2. Results and discussion
2.1. Synthesis and characterisation of
[WCl2(CO)(NCMe)(p2-EtC2Et)2] (1)
Reaction of [WCl2(CO)3(NCMe)2] (prepared in situ
as described previously [19]), with an excess of 3-hexyne
eventually gives the new bis(3-hexyne) complex
[WCl2(CO)(NCMe)(h2-EtC2Et)2] (1), which has been
characterised by IR (Table 2), H- and 13C-NMR spec-
1
troscopy (Tables 3 and 4). Complex 1 is very much less
stable than its diiodo analogue [WI2(CO)(NCMe)(h2-
EtC2Et)2] [20], and hence it was very difficult to obtain
satisfactory elemental analysis results, even after many
repeated attempts of preparing the complex from both
reaction of [WCl2(CO)3(NCMe)2] (prepared in situ)
with EtC2Et or treating [WI2(CO)(NCMe)(h2-EtC2Et)2]
with two equivalents of NaCl. It can be used for
reactions if used very quickly, but during the prepara-
tion of a sample for elemental analysis, it decomposes
before the pure sample is analysed. Complex 1 is also
less soluble in chlorinated solvents and diethyl ether
and hydrocarbon solvents compared to its diiodo ana-
logue [20]. The IR spectrum for 1 (CHCl3) has a strong
2.2. Reactions of [WCl2(CO)(NCMe)(p2-EtC2Et)2] (1)
with one equi6alent of L to gi6e
[WCl2(CO)L(p2-EtC2Et)2] (2–5)
Reaction of equimolar amounts of 1 and L {L=
NPh3, PPh3 or [MI2(CO)3{MeC(CH2PPh2)3-P,P%}]
(M=Mo or W)} in CH2Cl2 at room temperature gives
the acetonitrile exchanged products, [WCl2(CO)L(h2-
EtC2Et)2] (2–5). All the new complexes have been
characterised in the normal manner (see Tables 1–3)
and 13C-NMR for complex 2 (see Table 4). Complex 2
is less stable, and more soluble than the phosphine
Scheme 1.

M. Al-Jahdali, P.K. Baker / Journal of Organometallic Chemistry 628 (2001) 91–98
93
Table 1
Physical and analytical data a for the chlorocarbonyl 3-hexyne tungsten complexes (1–18)
Number Complex
Colour Yield (%)
Analysis (%)
C
H
N
1
2
3
4
[WCl2(CO)(NCMe)(h2-EtC2Et)2]
Green
Green
Green
Brown
39
64
48
39
37.2 (36.9)
54.3 (53.8)
47.9 (48.3)
45.1 (45.4)
3.6 (4.7)
4.9 (5.1)
4.4 4.7
1.0 (2.8)
2.6 (2.0)
[WCl2(CO)(NPh3)(h2-EtC2Et)2]
[WCl2(CO)(PPh3)(h2-EtC2Et)2]·CH2Cl2
[WCl2(CO)(LMo)(h2-EtC2Et)2],
4.7 (4.0)
L
Mo=[MoI2(CO)3{MeC(CH2PPh2)3-P,P%}]
5
[WCl2(CO)(LW)(h2-EtC2Et)2],
Green
Green
62
41
42.3 (42.9)
3.7 (3.7)
L
W=[WI2(CO)3{MeC(CH2PPh2)3-P,P%}]
6
7
8
9
10
11
12
13
14
15
16
17
18
[WCl2(CO)(PPh3)2(h2-EtC2Et)]
58.9 (58.1)
46.6 (45.9)
42.4 (42.9)
50.9 (51.2)
53.5 (53.6)
49.1 (49.3)
51.0 (50.5)
52.9 (52.1)
30.7 (31.1)
39.3 (38.4)
42.1 (42.4)
31.3 (31.7)
36.3 (36.5)
4.5 (4.5)
4.3 (3.6)
3.7 (3.3)
4.6 (4.3)
5.0 (5.4)
5.0 (4.6)
5.0 (4.9)
4.8 (4.2)
5.4 (5.5)
6.4 (6.7)
4.4 (4.7)
4.3 (4.9)
5.1 (5.5)
[WCl2(CO)(LMo)2(h2-EtC2Et)]
Brown 79
[WCl2(CO)(LW)2(h2-EtC2Et)]
Green
Green
Green
Green
Green
Green
Green
Green
Green
Green
Green
30
53
36
17
17
80
63
69
49
39
58
[WCl2(CO)(dppm)(h2-EtC2Et)]
[WCl2(CO)(dppp)(h2-EtC2Et)]·Et2O
[WCl2(CO)(dppb)(h2-EtC2Et)]
[WCl2(CO)(dpph)(h2-EtC2Et)]·CH2Cl2
[WCl2(CO)(cis-dppethy)(h2-EtC2Et)]
[WCl2(CO){P(OEt)3}2(h2-EtC2Et)]·CH2Cl2
[WCl2(CO){P(OiPr)3}2(h2-EtC2Et)]
[WCl(CO)(2,2%-bipyridyl)(h2-EtC2Et)2]Cl
[WCl(CO)(S2CNMe2)(h2-EtC2Et)2]·CH2Cl2
[WCl(CO)(S2CNEt2)(h2-EtC2Et)2]
4.9 (4.7)
3.2 (3.8)
3.4 (3.4)
a Calculated values in parentheses.
Table 2
Infrared data a for the chlorocarbonyl 3-hexyne tungsten complexes (1–18)
Complex
w(CꢁO) (cm−1
)
w(CꢁC) (cm−1
)
w(CꢁN) (cm−1
)
1
2
3
4
5
6
7
8
2079(s)
2081(s)
2064(s)
1630(w)
1587(w)
1644(w)
1619(w)
1609(w)
1640(w)
1622(w)
1625(w)
1601(w)
1604(w)
1636(w)
1635(w)
1602(w)
1621(w)
1641(w)
1605(w)
1605(w)
1646(w)
2305(w)
2075(s); 2044(s); 1970(s); 1934(s)
2079(s); 2034(s); 1958(s); 1905(s)
1995(s)
2044(s); 1972(s); 1938(s); 1904(s)
2038(s); 1990(s); 1962(s); 1907(s); 1901(s)
1936(s)
1944(s)
1932(s)
1935(s)
1963(s)
1958(s)
1951(s)
2052(s)
2043(s)
2041(s)
9
10
11
12
13
14
15
16
17
18
a Spectra recorded in CHCl3 as thin films between NaCl plates (s, strong; m, medium; w, weak).
complexes 3–5. All the complexes decompose very
quickly when exposed to air in solution, and are also
air-sensitive in the solid state, but can be stored under
dinitrogen for several weeks. Complex 2 has a single
carbonyl band in its IR spectrum at 2081 cm−1 (Table
2), in a similar position to 1, and would be expected to
have a similar structure as the acetonitrile complex
shown in Fig. 1. Also, the room temperature 13C{1H}-
NMR spectrum (CDCl3) of the most soluble complex
in this series, [WCl2(CO)(NPh3)(h2-EtC2Et)2] (2), shows
alkyne contact carbon resonances at l=168.98 and
162.30 ppm, which again indicates [23] that the two
3-hexyne ligands are donating a total of six electrons to
the metal in this complex, which enables the complex to
obey the effective atomic number rule.
The new organometallic phosphine ligands,
[MI2(CO)3{MeC(CH2PPh2)3-P,P%}] (M=Mo, W), have
been prepared by the reaction of equimolar amounts of

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M. Al-Jahdali, P.K. Baker / Journal of Organometallic Chemistry 628 (2001) 91–98
Table 3
1H-NMR data a for the chlorocarbonyl 3-hexyne tungsten complexes (1–18)
Complex
1H-NMR (l ppm)
1
2
3
3.4 (q, 8H, JHꢂH=7.5 Hz; CH2, hexyne), 2.6 (s, 3H, CH3CN), 1.3 (t, 12H, JHꢂH=7.5 Hz; CH3, hexyne)
7.4–6.9 (m, 15H, Ph), 3.35 (q, 8H, JHꢂH=7.5 Hz; CH2, hexyne), 1.3 (t, 12H, JHꢂH=7.5 Hz; CH3, hexyne)
7.7–7.1 (m, 15H, Ph), 5.3 (s, 2H, CH2Cl2), 3.6–3.1 (mq, 8H, CH2, hexyne), 1.3 (t, 6H, JHꢂH=8.5 Hz; CH3, hexyne), 0.9 (t,
6H, JHꢂH=8.5 Hz; CH3, hexyne)
4
5
7.7–7.0 (m, 30H, Ph), 3.25 (q, 8H, JHꢂH=7.5 Hz; CH2, hexyne), 2.25 (s, 6H, CH2, tripodal triphos), 1.2 (t, 12H, JHꢂH=7.5
Hz; CH3, hexyne), 0.9 (s, 3H, CH3, tripodal triphos)
7.7–7.1 (m, 30H, Ph), 3.45 (q, 8H, JHꢂH=8.5 Hz; CH2, hexyne), 2.7–2.2 (m, 6H, CH2, tripodal triphos), 1.3 (s, 3H, CH3,
tripodal triphos), 0.9 (t, 12H, JHꢂH=8.5 Hz; CH3, hexyne)
6
7
7.6–7.2 (m, 30H, Ph), 3.3 (q, 4H, JHꢂH=8.5 Hz; CH2, hexyne), 1.1 (t, 6H, JHꢂH=8.5 Hz; CH3, hexyne)
7.8–6.9 (m, 60H, Ph), 3.25 (q, 4H, JHꢂH=7.5 Hz; CH2, hexyne), 2.25 (s, 12H, CH2, tripodal triphos), 1.2 (t, 6H, JHꢂH=7.5
Hz; CH3, hexyne), 0.9 (s, 6H, CH3, tripodal triphos)
8
8.0–7.1 (m, 60H, Ph), 3.4 (q, 4H, JHꢂH=7.5 Hz; CH2, hexyne), 2.3–2.0 (m, 12H, CH2, tripodal triphos), 1.3 (t, 6H,
JHꢂH=7.5 Hz; CH3, hexyne), 0.9 (s, 6H, CH3, tripodal triphos)
9
7.6–7.0 (m, 20H, Ph), 4.8 (m, 2H, CH2, dppm), 3.6 (q, 4H, JHꢂH=7.5 Hz; CH2, hexyne), 1.1 (t, 6H, JHꢂH=7.5 Hz; CH3,
hexyne)
10
7.5–7.0 (m, 20H, Ph), 3.4 (q, 4H, JHꢂH=8.6 Hz; CH2, ether), 3.3 (q, 4H, JHꢂH=7.5 Hz; CH2, hexyne), 2.3 (m, 2H, CH2,
propane), 2.2 (m, 2H, CH2, propane), 1.9 (m, 2H, CH2, propane), 1.1 (t, 6H, JHꢂH=7.5 Hz; CH3, hexyne), 0.9 (t, 6H,
JHꢂH=8.6 Hz; CH3, ether)
11
12
13
14
15
7.7–6.9 (m, 20H, Ph), 3.3–2.7 (m, 4H, JHꢂH=8.2 Hz; CH2, hexyne), 2.3 (m, 4H, CH2PPh2, dppb), 1.3 (s, 4H, CH2, dppb),
0.9 (t, 6H, JHꢂH=8.2 Hz; CH3, hexyne)
7.7–7.0 (m, 20H, Ph), 3.4 (q, 4H, JHꢂH=7.5 Hz; CH2, hexyne), 2.3 (brm, 4H, CH2PPh2-dpph), 1.4 (brm, 8H, CH2, dpph),
0.9 (t, 6H, JHꢂH=7.5 Hz; CH3, hexyne)
7.8–7.1 (m, 20H, Ph), 3.6 (q, 4H, JHꢂH=8.5 Hz; CH2, hexyne), 3.3–3.0 (md, 2H, CH=CH), 1.2 (t, 6H, JHꢂH=8.5 Hz;
CH3, hexyne)
5.3 (s, 2H, CH2Cl2), 4.2–3.9 {dq, 12H, CH2, P(OEt)3}, 3.6 (q, 4H, JHꢂH=7.5 Hz; CH2, hexyne), 1.9–1.2 {dt, 18H, CH3,
P(OEt)3}, 1.1 (t, 6H, JHꢂH=7.5 Hz; CH3, hexyne)
4.8–4.5 (m, 6H, CH, isopropyl), 3.6 (q, 4H, JHꢂH=8.5 Hz; CH2, hexyne), 1.5–1.1 (md, 36H, CH3, isopropyl), 1.2 (t, 6H,
JHꢂH=8.5 Hz; CH3, hexyne)
16
17
9.0–7.4 (m, 8H, 2,2%-bipyridyl), 3.7 (mq, 8H, JHꢂH=8 Hz; CH2, hexyne), 1.2 (t, 12H, JHꢂH=8 Hz; CH3, hexyne)
5.3 (s, 2H, CH2Cl2), 3.45 (q, 8H, JHꢂH=8.5 Hz; CH2, hexyne), 3.1 (s, 6H, CH3, (Me)2ꢂNCS2), 1.2 (t, 12H, JHꢂH=8.5 Hz;
CH3, hexyne)
18
3.85 (q, 4H, JHꢂH=9 Hz; CH2, (Et)2ꢂNCS2), 3.5 (q, 8H, JHꢂH=8.5 Hz; CH2, hexyne), (t, 6H, JHꢂH=9 Hz; CH3,
(Et)2ꢂNCS2), 1.2 (t, 12H, JHꢂH=8.5 Hz; CH3, hexyne)
a Spectra recorded in CDCl3 (+25°C) and referenced to SiMe4 (s, singlet; br, broad; d, doublet; m, multiplet; q, quartet; t, triplet).
many complexes of this type have this structure [25–
27]. Hence, it is likely that the structure of 4 and 5 will
have LMo or LW replacing the acetonitrile in Fig. 1.
[MI2(CO)3(NCMe)2] and MeC(CH2PPh2)3 in CH2Cl2 at
room temperature [24]. For example, the complex
[WCl2(CO)(LMo)(h2-EtC2Et)2] (4) has carbonyl bands
at 2075, 2044, 1970 and 1934 cm−1. The band at 2075
cm−1 will be due to the carbonyl ligand on the tung-
sten dichloro centre, which is similar to
[WCl2(CO)(LW)(h2-EtC2Et)2] (5) which has 6(CO) at
2079 cm−1. The other three bands are due to the
WI2(CO)3-unit, which are related to the organometallic
phosphine, [WI2(CO)3{MeC(CH2PPh2)3-P,P%}] which
has carbonyl stretching bands at 2036, 1958 and 1904
cm−1 [24]. The 31P{1H}-NMR spectrum of 4 has a
single resonance at l=17.59 ppm due to the two
phosphorus atoms of the tripodal triphos attached to
the fluxional MoI2(CO)3-unit, and at 23.60 ppm due to
the third phosphorus atom, which is coordinated to the
tungsten bis(alkyne) unit, in a ca. 2:1 intensity ratio.
The structure of the seven-coordinate complexes,
[MI2(CO)3{MeC(CH2PPh2)3-P,P%}] part of the bimetal-
lic complexes are most likely to be capped octahedral as
Table 4
13C{1H}-NMR data a (l) for selected chlorocarbonyl 3-hexyne tung-
sten complexes
Complex
13C (l ppm)
1
9.50 (s, MeCN), 13.90 (s, CH3, hexyne), 28.99, 29.8
(s, CH2, hexyne), 129.5 (s, CꢁN), 162.43, 167.50 (s,
CꢁC), 193.57 (s, CꢁO)
13.84 (s, CH3, hexyne), 28.96 (s, CH2, hexyne),
122.68, 124.15, 129.184 (s, Ph), 147.84 (s, CꢁN),
162.30, 168.98 (s, CꢁC), 194.4 (s, CꢁO)
14.06, 14.48, 14.87 (s, CH3, hexyne), 27.92, 29.8,
33.72, 35.21 (s, CH2, hexyne), 122.49, 125.15, 126.48,
128.49, 139.27, 139.60, 142.64, 148.01, 150.51, 152.04,
153.34 (s, 2,2%-dipyridyl), 164.23, 168.98 (s, CꢁC),
189.30 (s, CꢁO)
2
16
a Spectra recorded in CDCl3 (+25°C) and referenced to SiMe4 (s,
singlet).

M. Al-Jahdali, P.K. Baker / Journal of Organometallic Chemistry 628 (2001) 91–98
95
Table 5
the solid state for a few hours. The complexes are much
less soluble in chlorinated solvents such as CH2Cl2 and
CHCl3 compared to 1–5.
31P{1H}-NMR data a (l) for selected chlorocarbonyl 3-hexyne tung-
sten complexes
The 31P{1H}-NMR spectrum of [WCl2(CO)-
(PPh3)2(h2-EtC2Et)] (6), has a single resonance at l=
−9.71 ppm, which suggests trans-PPh3 groups, which
would be expected due to the very large ligand cone
angle [28] of PPh3 (145°). This also agrees with all the
crystal structures of [MX2(CO)L2(h2-RC2R%)] (M=
Mo, X=Br, L=PEt3, R=H, R%=Ph [13]; M=W,
X=Cl, L=PMe3 or PMe2Ph, R=R%=Ph [15]; M=
W, X=Cl, L=PMe3, R=Ph, R%=NHtBu [17]; M=
W, X=I, L=PPh3, R=R%=Et [20]), which all have
trans-phosphine ligands. Hence, the most likely struc-
ture of complex 6 will be as shown in Fig. 2.
Complex
31P{1H}(d ppm)
3
4
6
7
−25.33 (s, PPh3)
17.59 (s, 2P, LMo), 23.60 (s, 1P, Ph2PꢂW)
−9.71 (s, trans, PPh3)
17.58 (s, 2P, LMo), 30.76 (s, 1P, Ph2PꢂW)
−23.99, −23.57 (d, JPꢂP=41.72 Hz, 2P of dppm)
−18.13, −17.62 (d, JPꢂP=52.22 Hz, 2P of dppp)
−10.39, −16.77 (d, JPꢂP=55.89 Hz, 2P of dppb)
−16.84, −10.27 (d, JPꢂP=66.54 Hz, 2P of dpph)
−23.83, −2.79 (d, JPꢂP=59.83 Hz, 2P of cis dppeth)
100.40 (s, trans), 107.26 (d, cis), 107.83 (d, cis)
(JPꢂP=57.72 Hz)
9
10
11
12
13
14
15
94.80 (s, trans) (JWꢂP=194.75 Hz)
1
The IR, H- and 31P{1H}-NMR spectroscopic prop-
a Spectra recorded in CDCl3 (+25°C) and referenced to 85%
H3PO4 (s, singlet; d, doublet).
erties of the trimetallic complexes, [WCl2(CO)(LMo or
LW)2(h2-EtC2Et)] (7 and 8) show the two LMo or LW
moieties are in the same environment, and would also
suggest
a trans-arrangement of these very large
monodentate phosphine ligands. For example,
[WCl2(CO)(LMo)2(h2-EtC2Et)] (7) has carbonyl bands
at w(CO)=2044, 1972, 1938, 1904 cm−1; the band at
{w(CO)=1972 cm−1} is likely to be due to the
WCl2(CO)-unit, and the bands w(CO)=2044, 1938 and
1904 cm−1 due to the MoI2(CO)3-unit in its IR spec-
trum (Table 2). The 31P{1H}-NMR spectrum (CDCl3,
+25°C) of 7 has resonances at l=17.58 and 30.76
ppm in a 2:1 intensity ratio. The resonance at l=17.58
is most likely to be due to the two phosphorus atoms
on the fluxional organomolybdenum phosphine ligand,
[MoI2(CO)3{MeC(CH2PPh2)3-P,P%}], which has a reso-
nance at l=12.63 ppm at room temperature for the
two coordinated phosphorus atoms [24]. The lower field
resonance at l=30.76 ppm will be due to the trans-
phosphorus atoms attached to the WCl2(CO)-centre.
The bidentate phosphine ligand complexes
[WCl2(CO)L2(h2-EtC2Et)] {L2=Ph2P(CH2)nPPh2; n=
1, 3, 4 or 6, or cis-Ph2PCHꢀCHPPh2} (9–13), are
related to, for example, the diiodo complexes
[WI2(CO){Ph2P(CH2)nPPh2}(h2-EtC2Et)] (n=1, 3, 4 or
6), which has been structurally characterised for n=3
[20]. In view of the similar spectroscopic properties of
[WX2(CO){Ph2P(CH2)3PPh2}(h2-EtC2Et)] {X=Cl (10),
w(CO)=1944 cm−1; X=I [20], w(CO)=1942 cm−1},
31P{1H}-NMR (for X=Cl, l= −18.13 and −17.62
ppm, for X=I [20], l= −23.73 and −36.21 ppm}, it
is likely that they will have a similar structure as shown
in Fig. 3.
Fig. 2. Proposed structure of [WCl2(CO)(PPh3)2(h2-EtC2Et)] (6).
Fig. 3. Proposed structure of [WCl2(CO){Ph2P(CH2)3PPh2}(h2-
EtC2Et)] (10).
2.3. Reactions of 1 with two equi6alents of L
{L=PPh3, LMo, LW}, or one equi6alent of L2
{L2=Ph2P(CH2)nPPh2 (n=1, 3, 4 or 6) or
cis-Ph2PCHꢀCHPPh2} to gi6e
[WCl2(CO)L2(p2-EtC2Et)] (6–13)
Treatment of 1 with L2 {L2=2PPh3, 2LMo, 2LW,
Ph2P(CH2)nPPh2 (n=1, 3,
4
or 6) or cis-
Ph2PCHꢀCHPPh2} in CH2Cl2 at room temperature,
eventually gave the mono(3-hexyne) complexes,
[WCl2(CO)L2(h2-EtC2Et)] (6–13). All the new com-
plexes 6–13 have been characterised in the normal
manner (Tables 1–5). Complex 10 was confirmed as an
Et2O solvate and 12 as a CH2Cl2 solvate by repeated
2.4. Reactions of [WCl2(CO)(NCMe)(p2-EtC2Et)2] (1)
i
with two equi6alents of P(OR)3 (R=Et, Pr) to gi6e
1
elemental analyses and H-NMR spectroscopy. These
[WCl2(CO){P(OR)3}2(p2-EtC2Et)] (14 and 15)
bis(phosphine) complexes are considerably more stable
than 1–5, and can be stored for several weeks under a
nitrogen atmosphere. They are also stable in the air in
Reaction of 1 with two equivalents of P(OR)3
(R=Et, iPr) in diethyl ether gives the expected bis(phos-

96
M. Al-Jahdali, P.K. Baker / Journal of Organometallic Chemistry 628 (2001) 91–98
phite) complexes, [WCl2(CO){P(OR)3}2(h2-EtC2Et)] (14
and 15) in high yield. These complexes are very soluble
in chlorinated solvents such as CH2Cl2 and CHCl3, and
are also soluble in diethyl ether. These complexes have
been fully characterised by elemental analysis (Table 1)
and spectroscopic methods (see Tables 2–5). Complex
14 was confirmed as a CH2Cl2 solvate by repeated
elemental analyses and 1H-NMR spectroscopy. They
are very air-sensitive in solution when exposed to air,
but can be stored for a few hours in the solid state
under dinitrogen. Complexes 14 and 15 are the most
soluble complexes described in this paper. The synthesis
and crystallographic characterisation of a large series of
diiodo bis(phosphite) complexes have been described of
the type, cis-[WI2(CO){P(OMe)3}2(h2-MeC2Me)] [6],
trans-[MoI2(CO){P(OEt)3}2(h2-MeC2Me)] [29] and
trans-[MI2(CO){P(OiPr)3}2(h2-EtC2Et)] (M=Mo or
W) [30]. The 31P{1H}-NMR spectrum of 14 shows a
singlet resonance at l=100.40 ppm, which is due to
the trans-isomer, and two doublets at l=107.26 and
107.83 ppm, due to the cis-isomer (JPꢂP=57.72 Hz)
(the ratio of cis- to trans-isomers is approximately
40:60). Whereas, for R=iPr (15) only a single reso-
nance at l=94.80 ppm (JWꢂP=194.75 Hz) due to the
trans-isomer was observed. The proposed structures of
the cis- and trans-isomers of 14 are shown in Fig. 4(a)
and (b), respectively, which correspond with the crystal
structures of related diiodo complexes [6,29,30].
2.5. Reaction of [WCl2(CO)(NCMe)(p2-EtC2Et)2] (1)
with 2,2%-bipyridyl (bipy) to gi6e
[WCl(CO)(bipy)(p2-EtC2Et)2]Cl (16)
Treatment of equimolar quantities of [WCl2(CO)-
(NCMe)(h2-EtC2Et)2] and 2,2%-bipyridyl (bipy) in
CH2Cl2 at room temperature affords the cationic com-
plex, [WCl(CO)(bipy)(h2-EtC2Et)2]Cl (16) in high yield.
Complex 16 has been characterised in the normal man-
ner (see Tables 1–4), and is closely related to the
crystallographically characterised complexes [WI(CO)-
(bipy)(h2-MeC2Me)2]I [4] and [WCl(CO)(bipy)(h2-
MeC2Me)2]I [12], and both have cis- and parallel 2-bu-
tyne ligands, which are in the equatorial plane with the
2,2%-bipyridine ligand, with the carbonyl and halide
ligands occupying the axial sites.
In view of the very similar spectroscopic properties of
16 to the crystallographically characterised complexes
[WI(CO)(bipy)(h2-MeC2Me)2]I [4] and [WCl(CO)-
(bipy)(h2- MeC2Me)2]I [12], it is likely to have the same
structure as shown in Fig. 5. The 13C{1H}-NMR spec-
trum (Table 4) of 16 has alkyne contact carbon reso-
nances at l=164.23 and 168.98 ppm due to the two
alkyne ligands donating a total of six electrons to the
tungsten, which also enables the complex to obey the
effective atomic number rule [23].
2.6. Reactions of [WCl2(CO)(NCMe)(p2-EtC2Et)2] (1)
with one equi6alent of NaS2CNR2·3H2O (R=Me, Et)
to gi6e [WCl(CO)(S2CNR2)(p2-EtC2Et)2] (17 and 18)
Reaction of [WCl2(CO)(NCMe)(h2-EtC2Et)2] with
one equivalent of NaS2CNR2·3H2O (R=Me, Et) in
CH2Cl2 at room temperature gives the complexes,
[WCl(CO)(S2CNR2)(h2-EtC2Et)2] (17 and 18) in high
yield. These fully characterised complexes (Tables 1–4)
are very similar to the crystallographically characterised
complex, [WI(CO)(S2CNC4H8)(h2-MeC2Me)2] [7], pre-
viously described. Complex 17 was confirmed as a
CH2Cl2 solvate by repeated elemental analyses and
1H-NMR spectroscopy. The IR and NMR spectral
properties of 17 and 18 are similar to the complex,
[WI(CO)(S2CNC4H8)(h2-MeC2Me)2], and hence they
are likely to have a similar structure as shown in Fig. 6.
In conclusion, the synthesis of an unstable dichloro
bis(alkyne) complex, [WCl2(CO)(NCMe)(h2-EtC2Et)2]
(1) has been described, and its reactions with a wide
range of neutral and anionic donor ligands to give a
series of more stable products has been described, as
shown in Scheme 1.
Fig. 4. Proposed structure of both the cis- (a) and trans- (b) isomers
i
of [WCl2(CO){P(OR)3}2(h2-EtC2Et)] {(14) and Pr (15)}.
Fig. 5. Proposed structure of [WCl(CO)(bipy)(h2-EtC2Et)2]Cl (16).

M. Al-Jahdali, P.K. Baker / Journal of Organometallic Chemistry 628 (2001) 91–98
97
moval of solvent in vacuo after 24 h, gave the green
powder [WCl2(CO)(NPh3)(h2-EtC2Et)2] (2), which was
recrystallised from CH2Cl2–Et2O at −17°C (yield of
pure product=0.18 g, 64%).
Similar reactions of [WCl2(CO)(NCMe)(h2-EtC2Et)2]
with one equivalent of L in CH2Cl2 at room tempera-
ture (r.t.) gave the complexes [WCl2(CO)(L)(h2-
EtC2Et)2] {L=PPh2 (3), LMo (4), LW (5)}. For physical
and analytical data see Table 1.
Fig. 6. Proposed structure of [WCl(CO)(S2CNR2)(h2-EtC2Et)2] {R=
Me (17); R=Et (18)}.
3.4. Preparation of [WCl2(CO)(PPh3)2(p2-EtC2Et)] (6)
To a stirred solution of [WCl2(CO)(NCMe)(h2-
EtC2Et)2] (1) (0.1 g, 0.20 mmol) in CH2Cl2 (25 cm3) was
added PPh3 (0.10 g, 0.38 mmol). Filtration, and re-
moval of solvent in vacuo after 24 h, gave the green
powder of [WCl2(CO)(PPh3)2(h2-EtC2Et)] (6), which
was recrystallised from CH2Cl2/Et2O at −17°C (yield
of pure product=0.08 g, 41%).
3. Experimental
3.1. Reagents and general techniques
The reactions described in this research were carried
out using standard vacuum/Schlenk line techniques.
The starting material, [WCl2(CO)3(NCMe)2], was pre-
pared in situ by reacting [WI2(CO)3(NCMe)2] with two
equivalents of NaCl in acetone, as previously described
[19]. The solvent CH2Cl2 was dried over calcium hy-
dride and diethyl ether was dried over sodium wire. All
chemicals used were purchased from commercial
sources.
Elemental analyses (C, H and N) were determined
using a Carlo Erba Elemental Analyser MOD1108
(using helium as the carrier gas). IR spectra were
recorded as thin CHCl3 films on a Perkin–Elmer
FT1600 series IR spectrophotometer. 1H-, 13C{1H}-
and 31P{1H}-NMR spectra were recorded on a Bruker
AC 250 MHz NMR spectrometer, and spectra were
referenced to SiMe4 (1H and 13C) or 85% H3PO4 (31P).
Similar reactions of [WCl2(CO)(NCMe)(h2-EtC2Et)2]
(1) with two equivalents of L in CH2Cl2 at r.t. gave the
complexes, [WCl2(CO)(L)2(h2-EtC2Et)] {L=LMo (7),
LW (8)}. For physical and analytical data see Table 1.
3.5. Preparation of [WCl2(CO)(dppm)(p2-EtC2Et)] (9)
To a stirred solution of [WCl2(CO)(NCMe)(h2-
EtC2Et)2] (1) (0.1 g, 0.20 mmol) in CH2Cl2 (25 cm3) at
r.t. was added Ph2P(CH2)PPh2 (0.078 g, 0.20 mmol).
Filtration and removal of solvent in vacuo after 24 h,
gave the green powder, [WCl2(CO)(dppm)(h2-EtC2Et)]
(9), which was recrystallised from CH2Cl2–Et2O at
−17°C (yield of pure product=0.09 g, 53%).
Similar reactions of [WCl2(CO)(NCMe)(h2-EtC2Et)2]
‚
‚
(1) with one equivalent of L L {L L=Ph2P(CH2)n-
‚
PPh2, n=3 (10), n=4 (11), n=6 (12), L L=cis-
3.2. Preparation of [WCl2(CO)(NCMe)(p2-EtC2Et)2]
(1)
Ph2PCHꢀCHPPh2 (13)} in CH2Cl2 at r.t. gave the
‚
complexes, [WCl2(CO)(L L)(h2-EtC2Et)] (10–13). For
physical and analytical data see Table 1.
To
a stirred solution of [WCl2(CO)3(NCMe)2]
{prepared in situ by reaction of [WI2(CO)3(NCMe)2]
(0.5 g, 0.82 mmol) with two equivalents of NaCl (0.096
g, 1.6 mmol)} (0.5 g, 1.2 mmol) in CH2Cl2 (25 cm3) was
added excess of EtC2Et (0.19 g, 0.27 ml, 2.3 mmol).
Filtration and removal of solvent in vacuo after 24 h,
gave the green oily product of [WCl2(CO)(NCMe)(h2-
EtC2Et)2] (1), which was recrystallised several times
from CH2Cl2–Et2O at −17°C (yield of product=0.23
g, 39%).
3.6. Preparation of [WCl2(CO){P(OEt)3}2(p2-EtC2Et)]
(14)
To a stirred solution of [WCl2(CO)(NCMe)(h2-
EtC2Et)2] (1) (0.1 g, 0.20 mmol) in Et2O (25 cm3) was
added P(OEt)3 (0.068 g, 0.007 ml, 0.40 mmol). Filtra-
tion and removal of solvent in vacuo after 24 h, gave
the green powder of [WCl2(CO){P(OEt)3}2(h2-EtC2Et)]
(14), which was recrystallised from CH2Cl2–Et2O at
−17°C (yield of pure product=0.09 g, 63%).
3.3. Preparation of [WCl2(CO)(NPh3)(p2-EtC2Et)2] (2)
A
similar reaction of [WCl2(CO)(NCMe)(h2-
EtC2Et)2] (1) with two equivalents of P(OiPr)3 in Et2O
at r.t. gave the complex, [WCl2(CO){P(OiPr)3}2(h2-
EtC2Et)] (15). For physical and analytical data see
Table 1.
To a stirred solution of [WCl2(CO)(NCMe)(h2-
EtC2Et)2] (1) (0.2 g, 0.41 mmol) in CH2Cl2 (25 cm3) was
added NPh3 (0.10 g, 0.40 mmol). Filtration and re-

98
M. Al-Jahdali, P.K. Baker / Journal of Organometallic Chemistry 628 (2001) 91–98
3.7. Preparation of [WCl(CO)(bipy)(p2-EtC2Et)2]Cl
(16)
[4] P.K. Baker, E.M. Armstrong, M.G.B. Drew, Inorg. Chem. 27
(1988) 2287.
[5] E.M. Armstrong, P.K. Baker, M.E. Harman, M.B. Hursthouse,
J. Chem. Soc. Dalton Trans. (1989) 295.
[6] P.K. Baker, E.M. Armstrong, M.G.B. Drew, Inorg. Chem. 28
(1989) 2406.
[7] E.M. Armstrong, P.K. Baker, K.R. Flower, M.G.B. Drew, J.
Chem. Soc. Dalton Trans. (1990) 2535.
[8] P.K. Baker, Adv. Organomet. Chem. 40 (1996) 45 (and refer-
ences cited therein).
[9] P.K. Baker, Chem. Soc. Rev. 27 (1998) 125 (and references cited
therein).
[10] P.K. Baker, D.J. Muldoon, A.J. Lavery, A. Shawcross, Polyhe-
dron 13 (1994) 2915.
To a stirred solution of [WCl2(CO)(NCMe)(h2-
EtC2Et)2] (1) (0.15 g, 0.30 mmol) in CH2Cl2 (25 cm3)
was added bipy (0.045 g, 0.28 mmol). Filtration and
removal of solvent in vacuo after 24 h, gave the green
powder, [WCl(CO)(bipy)(h2-EtC2Et)2]Cl (16), which
was recrystallised from CH2Cl2–Et2O at −17°C (yield
of pure product=0.09 g, 49%).
3.8. Preparation of [WCl(CO)(S2CNMe2)(p2-EtC2Et)2]
(17)
[11] P.K. Baker, A. Bury, K.R. Flower, Polyhedron 8 (1989) 2587.
[12] (a) P.K. Baker, M.G.B. Drew, M.M. Meehan, H.K. Patel, A.
White, J. Chem. Res. (S) (1998) 379. (b) P.K. Baker, M.G.B.
Drew, M.M. Meehan, H.K. Patel, A. White, J. Chem. Res. (M)
(1998) 1461.
[13] P.B. Winston, S.J.N. Burgmayer, J.L. Templeton, Organometal-
lics 5 (1986) 1707.
[14] B.J. Brisdon, A.G.W. Hodson, M.F. Mahon, K.C. Molloy, R.A.
Walton, Inorg. Chem. 29 (1990) 2701.
[15] G.R. Clark, A.J. Nielson, A.D. Rae, C.E.F. Rickard, J. Chem.
Soc. Dalton Trans. (1994) 1783.
[16] A. Mayr, C.M. Bastos, J. Am. Chem. Soc. 112 (1990) 7797.
[17] A. Mayr, C.M. Bastos, R.T. Chang, J.X. Haberman, K.S.
Robinson, D.A. Belle-Oudry, Angew. Chem. Int. Ed. Engl. 31
(1992) 747.
[18] A. Mayr, K.S. Lee, M.A. Kjelsberg, D. Van Engen, J. Am.
Chem. Soc. 108 (1986) 6079.
[19] M. Al-Jahdali, P.K. Baker, A.J. Lavery, M.M. Meehan, D.J.
Muldoon, J. Mol. Catal. 159 (2000) 51.
To a stirred solution of [WCl2(CO)(NCMe)(h2-
EtC2Et)2] (1) (0.15 g, 0.3 mmol) in CH2Cl2 (25 cm3) was
added NaS2CNMe2·3H2O (0.023 g, 0.3 mmol). Filtra-
tion and removal of solvent in vacuo after 24 h, gave
the green powder [WCl(CO)(S2CNMe2)(h2-EtC2Et)2]
(17), which was recrystallised from CH2Cl2–Et2O at
−17°C (yield of pure product=0.07 g, 39%).
A
similar reaction of [WCl2(CO)(NCMe)(h2-
EtC2Et)2] (1) with one equivalent of NaS2CNEt2·3H2O
in CH2Cl2 at r.t. gave the complex [WCl(CO)-
(S2CNEt2)(h2-EtC2Et)2] (18). For physical and analyti-
cal data see Table 1.
[20] M. Al-Jahdali, P.K. Baker, M.G.B. Drew, Z. Naturforsch. B 54
(1999) 171.
[21] P.K. Baker, M.E. Harman, M.B. Hursthouse, A.J. Lavery,
K.M.A. Malik, D.J. Muldoon, A. Shawcross, J. Organomet.
Chem. 484 (1994) 169.
Acknowledgements
[22] M.G.B. Drew, P.K. Baker, D.J. Muldoon, A.J. Lavery, A.
Shawcross, Gazz. Chim. Ital. 126 (1996) 625.
[23] J.L. Templeton, B.C. Ward, J. Am. Chem. Soc. 102 (1980) 3288.
[24] M. Al-Jahdali, P.K. Baker, M.M. Meehan, J. Chem. Soc. Dalton
Trans., submitted for publication.
M.Al.J. thanks the Saudi Arabian Government for
support.
[25] M.G.B. Drew, Prog. Inorg. Chem. 23 (1977) 67 (and references
cited therein).
References
[26] M. Meln´ık, P. Sharrock, Coord. Chem. Rev. 65 (1985) 49 (and
references cited therein).
[1] (a) E.M. Armstrong, P.K. Baker, S.G. Fraser, J. Chem. Res. (S)
(1988) 52. (b) E.M. Armstrong, P.K. Baker, S.G. Fraser, J.
Chem. Res. (M) (1988) 410.
[2] E.M. Armstrong, P.K. Baker, M.G.B. Drew, Organometallics 7
(1988) 319.
[27] C.W. Haigh, P.K. Baker, Polyhedron 13 (1994) 417.
[28] C.A. Tolman, Chem. Rev. 77 (1977) 313.
[29] P.K. Baker, M.G.B. Drew, D.S. Evans, A.W. Johans, M.M.
Meehan, J. Chem. Soc. Dalton Trans. (1999) 2541.
[30] M. Al-Jahdali, P.K. Baker, M.G.B. Drew, J. Organomet. Chem.
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[3] P.K. Baker, M.G.B. Drew, S. Edge, S.D. Ridyard, J.
Organomet. Chem. 409 (1991) 207.
.