Tripodal triphos MeC(CH2PPh2)3 complexes of molybdenum(II) and tungsten(II). Reactions of [MI2(CO) 3{MeC(CH2PPH2)3-P,P′}] (M = Mo or W) with molybdenum(II) and tungsten(II) complexes

Article abstract of DOI:10.1016/S0022-328X(01)01367-5

Equimolar quantities of [MI₂(CO)₃ (NCMe)₂] (M = Mo or W) and tripodal triphos {MeC(CH₂PPh₂)₃} react in CH₂Cl₂ at room temperature for 5 min to give [MI₂(CO)₃{MeC(CH₂ PPh₂)₃-P,P'}] (1 and 2) which contain one uncomplexed phosphorus donor atom capable of further coordination. Complexes 1 and 2 react in refluxing CHCl₃ for 15 h (M = Mo) or 72 h (M = W) to give the complexes [MI₂(CO)₂ {MeC(CH₂PPh₂)₃-P,P',P″}] (3 and 4). The complexes [MI₂(CO)₃(NCMe)₂] (M = Mo or W) react with two equivalents of 1 (L^Mo) and 2 (L^W) to yield the trimetallic complexes [MI₂(CO)₃(L^Mo or L^W) ₂] (5-8). A series of mixed-ligand seven-coordinate bimetallic complexes of the type [MI₂(CO)₃L(L^Mo or L^W)] {M = Mo or W; L = PPh₃, AsPh₃, SbPh₃; for M = W, P(OR)₃ (R = Me, Et, Ph)} (9-17) have been prepared by reaction of [MI₂(CO)₃ (NCMe)₂] with one equivalent of L to give [MI₂ (CO)₃(NCMe)L], followed by an in situ reaction with L ^Mo or L^W. Similarly, reactions of [MI₂ (CO)₃{Ph₂P(CH₂)_nPPh ₂}] {n = 1 or 2} (prepared in situ) with equimolar amounts of L^Mo or L^W affords the cationic complexes, [MI(CO)₃)(L^Mo or L^W) {Ph₂ P(CH₂)_nPPh₂}]I (18-21). Reaction of equimolar quantities of [MI₂(CO)(NCMe)(η²-EtC ₂Et)₂] and L^Mo (for M = Mo) or L^W (for M = W) affords the acetonitrile displaced products, [MI₂(CO)(L^Mo or L^W)(η² -EtC₂Et)₂] (22) and (23). Treatment of [MI₂(CO)(NCMe)(η²-EtC₂Et) ₂] with two equivalents of L^Mo (for M = Mo) or L^W (for M = W) gives the mono(3-hexyne) trimetallic complexes [MI₂(CO)(L^Mo or L^W) ₂(η²-EtC₂Et)] (24) and (25). All the new complexes described in this paper have been characterised by elemental analysis, IR, ¹H- and ³¹P-NMR spectroscopy.

Full text of DOI:10.1016/S0022-328X(01)01367-5

Journal of Organometallic Chemistry 648 (2002) 99–108
www.elsevier.com/locate/jorganchem
Tripodal triphos {MeC(CH2PPh2)3} complexes of molybdenum(II)
and tungsten(II). Reactions of [MI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]
(M=Mo or W) with molybdenum(II) and tungsten(II) complexes
Paul K. Baker *, Mutlaq Al-Jahdali, Margaret M. Meehan
Department of Chemistry, Uni6ersity of Wales, Bangor, Gwynedd LL57 2UW, UK
Received 10 July 2001; received in revised form 16 October 2001
Abstract
Equimolar quantities of [MI2(CO)3(NCMe)2] (M=Mo or W) and tripodal triphos {MeC(CH2PPh2)3} react in CH2Cl2 at room
temperature for 5 min to give [MI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] (1 and 2) which contain one uncomplexed phosphorus donor
atom capable of further coordination. Complexes 1 and 2 react in refluxing CHCl3 for 15 h (M=Mo) or 72 h (M=W) to give
the complexes [MI2(CO)2{MeC(CH2PPh2)3ꢀP,P%,P¦}] (3 and 4). The complexes [MI2(CO)3(NCMe)2] (M=Mo or W) react with
two equivalents of 1 (LMo) and 2 (LW) to yield the trimetallic complexes [MI2(CO)3(LMo or LW)2] (5–8). A series of mixed-ligand
seven-coordinate bimetallic complexes of the type [MI2(CO)3L(LMo or LW)] {M=Mo or W; L=PPh3, AsPh3, SbPh3; for M=W,
P(OR)3 (R=Me, Et, Ph)} (9–17) have been prepared by reaction of [MI2(CO)3(NCMe)2] with one equivalent of L to give
[MI2(CO)3(NCMe)L], followed by an in situ reaction with LMo or LW. Similarly, reactions of [MI2(CO)3{Ph2P(CH2)nPPh2}]
{n=1 or 2} (prepared in situ) with equimolar amounts of LMo or LW affords the cationic complexes, [MI(CO)3(LMo or
LW){Ph2P(CH2)nPPh2}]I (18–21). Reaction of equimolar quantities of [MI2(CO)(NCMe)(h2-EtC2Et)2] and LMo (for M=Mo) or
LW (for M=W) affords the acetonitrile displaced products, [MI2(CO)(LMo or LW)(h2-EtC2Et)2] (22) and (23). Treatment of
[MI2(CO)(NCMe)(h2-EtC2Et)2] with two equivalents of LMo (for M=Mo) or LW (for M=W) gives the mono(3-hexyne)
trimetallic complexes [MI2(CO)(LMo or LW)2(h2-EtC2Et)] (24) and (25). All the new complexes described in this paper have been
1
characterised by elemental analysis, IR, H- and 31P-NMR spectroscopy. © 2002 Elsevier Science B.V. All rights reserved.
Keywords: Molybdenum; Tungsten; Tripodal ligand; Triphos
1. Introduction
been prepared by reacting [M(CO)4{PhP(CH2CH2-
PPh2)2ꢀP,P%}] with [M%(CO)5(NCMe)].
Although a wide variety of trimetallic complexes
containing bridging phosphine ligands such as bis-
(diphenylphosphino)methane has been prepared and
characterised [1–24], hitherto very few examples con-
taining bridging-tridentate phosphines such as chain
triphos {PhP(CH2CH2PPh2)2} or tripodal triphos
{MeC(CH2PPh2)3} have been described. In 1994,
Horng et al. [25] described the synthesis and character-
isation of the chain-triphos bridged complexes
[{M(CO)5}3{m3-PhP(CH2CH2PPh2)2ꢀP,P%,P¦}] (M=Cr,
Mo). More recently [26], the mixed-metal complexes
[(OC)4M(m2-PhP(CH2CH2PPh2)2ꢀP,P%,P¦}M%(CO)5]
(M=Cr, M%=Mo, W; M=Mo, M%=Cr, W) have
In 1986 [27], we described the synthesis and charac-
terisation of the highly versatile seven-coordinate com-
plexes, [MI2(CO)3(NCMe)2] (M=Mo or W). These
complexes have a wide range of chemistry [28,29]. In
1994 [30], we described the reaction of equimolar quan-
tities of [MI2(CO)3(NCMe)2] and linear triphos
{PhP(CH2CH2PPh2)2}, to initially yield [MI2(CO)3-
{PhP(CH2CH2PPh2)2ꢀP,P%}], which eventually react in-
tramolecularly to give, [MI2(CO)2{PhP(CH2CH2-
PPh2)2ꢀP,P%,P¦}]. Preliminary studies of the reactions
of [WI2(CO)3{PhP(CH2CH2PPh2)2ꢀP,P%}] as a mono-
dentate phosphine ligand have been described [30].
More recently [31,32], we have described the synthesis
and crystallographic characterisation of the mono-
phosphine alkyne complexes, [WX2(CO){PhP(CH2-
CH2PPh2)2ꢀP,P%}(h2-RC2R%)] (X=I, R=R%=Me [31],
* Corresponding author. Tel.: +44-1248-351151; fax: +44-1248-
370528.
E-mail address: chs018@bangor.ac.uk (P.K. Baker).
0022-328X/02/$ - see front matter © 2002 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(01)01367-5

100
P.K. Baker et al. / Journal of Organometallic Chemistry 648 (2002) 99–108
Ph [32]; R=Me, R%=Ph [31]; X=Br, R=R%=Ph
[32]). The reactions of the diiodo complexes as
monodentate phosphines with molybdenum(II) and
tungsten(II) complexes [31], molybdenum(II) p-allyl
complexes [33] and iron carbonyl complexes[34] have
been described.
In this paper, we describe the synthesis and charac-
terisation of the seven-coordinate tripodal triphos
organometallic phosphine ligands, [MI2(CO)3{MeC-
(CH2PPh2)3ꢀP,P%}] (M=Mo or W) and their in-
tramolecular rearrangement to the dicarbonyl com-
plexes, [MI2(CO)2{MeC(CH2PPh2)3ꢀP,P%,P¦}]. We also
report the reactions of the monodentate phosphine
[MI2(CO)3(NCMe)2] (M=Mo and W) have been pre-
pared by reacting the zero-valent complexes, fac-
[M(CO)3(NCMe)3] (prepared in situ) with an equimolar
quantity of I2 at 0 °C [27]. Equimolar quantities of
[MI2(CO)3(NCMe)2] and tripodal triphos, {MeC(CH2-
PPh2)3} react in CH2Cl2 at room temperature for 5 min,
to give the new complexes [MI2(CO)3{MeC(CH2-
PPh2)3ꢀP,P%}] (1 and 2), which have the tripodal
triphos ligand attached in a bidentate manner. Com-
plexes 1 and 2 have been fully characterised by elemen-
1
tal analysis (C, H and N) (Table 1), IR (Table 2), H-
and 31P{1H}-NMR spectroscopy (Tables 3 and 4). The
complexes are air-sensitive in solution, but can be
stored for several months in the solid state under
nitrogen in the absence of light. They are soluble in
polar chlorinated solvents such as CH2Cl2 and CHCl3,
but only slightly soluble in hydrocarbon solvents and
diethyl ether.
ligands, [MI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] with
a
range of molybdenum(II) and tungsten(II) complexes to
give a series of bi- and trimetallic tripodal triphos-
bridged complexes.
The bidentate coordination mode of the tripodal
triphos ligand in complexes 1 and 2 is confirmed by
both the IR (Table 2) and 31P{1H}-NMR spectral data
(Table 4). The IR spectra of 1 and 2 show three
carbonyl bands in their spectra (Table 2), with the
apparent absence of any isomers in solution. This is by
contrast to the analogous linear triphos tungsten com-
2. Results and discussion
2.1. Synthesis and characterisation of
[MI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] (1 and 2) and
[MI2(CO)2{MeC(CH2PPh2)3ꢀP,P%,P¦}] (3 and 4)
The starting materials used in this research, namely
Table 1
Physical and analytical dataa for the tripodal triphos {MeC(CH2PPh2)3} complexes of molybdenum(II) and tungsten(II) 1–25
Complex
Colour
Yield (%)
Analysis (%)
C
H
[MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}], (1)
[WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}], (2)
[MoI2(CO)2{MeC(CH2PPh2)3ꢀP,P%,P¦}], (3)
[WI2(CO)2{MeC(CH2PPh2)3ꢀP,P%,P¦}], (4)
[MoI2(CO)3[m-MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]2]·2Et2O, (5)
[WI2(CO)3[m-MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]2], (6)
[MoI2(CO)3[m-WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]2], (7)
[WI2(CO)3[m-WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]2], (8)
[MoI2(CO)3(PPh3)[m-MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]]·Et2O, (9)
[MoI2(CO)3(AsPh3)[m-MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]], (10)
[MoI2(CO)3(SbPh3)[m-MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]], (11)
[WI2(CO)3(PPh3)[m–WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]], (12)
[WI2(CO)3(AsPh3)[m-WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]], (13)
[WI2(CO)3(SbPh3)[m-WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]], (14)
[WI2(CO)3{P(OMe)3}[m-WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]], (15)
[WI2(CO)3{P(OEt)3}[m-WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]], (16)
[WI2(CO)3{P(OPh)3}[m-WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]], (17)
[MoI(CO)3{Ph2P(CH2)PPh2}[m-MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]]I, (18)
[WI(CO)3{Ph2P(CH2)PPh2}[m-WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]]I, (19)
[MoI(CO)3{Ph2P(CH2)2PPh2}[m-MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]]I, (20)
[WI(CO)3{Ph2P(CH2)2PPh2}[m-WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]]I, (21)
[MoI2(CO)[m-MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}](h2-EtC2Et)2], (22)
[WI2(CO)[m-WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}](h2-EtC2Et)2], (23)
[MoI2(CO)[m-MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]2(h2-EtC2Et)], (24)
[WI2(CO)[m-WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]2(h2-EtC2Et)], (25)
Brown
Orange
Brown
Orange
Brown
Brown
Yellow
Orange
Brown
Brown
Brown
Orange
Yellow
Orange
Yellow
Orange
Yellow
Brown
Orange
Brown
Yellow
Brown
Yellow
Brown
Orange
80
91
66
86
87
78
20
85
90
81
70
85
27
89
58
62
59
64
71
74
66
65
56
73
73
49.7 (49.9)
46.4 (46.1)
50.1 50.0)
46.5 (46.2)
44.7 (44.1)
41.1 (41.4)
40.2 (40.0)
38.6 (38.8)
46.2 (46.0)
43.0 (43.4)
42.0 (42.2)
40.1 (40.4)
40.1 (39.5)
38.9 (38.6)
34.0 (33.5)
35.4 (34.7)
39.5 (39.5)
45.6 (45.9)
42.4 (42.1)
45.8 (46.2)
42.4 (42.4)
42.3 (42.7)
38.5 (38.5)
44.5 (44.2)
40.3 (40.1)
3.6 (3.7)
3.5 (3.4)
3.8 (3.8)
3.4 (3.5)
3.6 (3.7)
3.0 (3.0)
3.2 (2.9)
3.1 (2.8)
3.5 (3.9)
3.2 (3.0)
3.2 (3.0)
3.0 (2.8)
3.0 (2.8)
2.8 (2.7)
2.9 (2.7)
3.0 (3.0)
2.8 (2.8)
3.4 (3.3)
2.9 (3.0)
3.3 (3.3)
3.1 (2.9)
3.6 (3.7)
3.4 (3.4)
3.9 (3.4)
3.5 (3.1)
a Calculated values in parenthesis.

P.K. Baker et al. / Journal of Organometallic Chemistry 648 (2002) 99–108
101
Table 2
Table 3
Infrared data for the tripodal triphos {MeC(CH2PPh2)3} complexes
of molybdenum(II) and tungsten(II) 1–25
1H-NMR spectral data for the tripodal triphos {MeC(CH2PPh2)3}
complexes of molybdenum(II) and tungsten(II) 1–25
Complex
w(CꢁO) (cm−1
)
w(CꢁC) (cm−1
)
Complex
1H-NMR data (l (ppm))
1
2
3
4
5
6
2041s, 1938s, 1917s
2036s, 1958s, 1904s
1936s, 1836s
–
–
–
–
–
–
1
2
3
4
5
7.65–7.15 (v.br, 30H, Ph); 2.55–2.1 (v.br,m, 6H,
CH2); 1.35 (s, 3H, CH3)
7.8–7.1 (v.br, 30H, Ph); 2.5–2.1 (v.br, 6H, CH2); 1.4
(s, 3H, CH3)
7.65–7.05 (v.br,m, 30H, Ph); 2.3–1.9 (br, 6H, CH2);
1.1 (s, 3H, CH3)
7.7–7.3 (br, 30H, Ph); 2.5–2.2 (br, m, 6H, CH2); 1.2
(s, 3H, CH3)
7.9–7.0 (v.br,m, 60H, Ph); 3.5 (q, 8H, CH2, diethyl
ether); 2.5 (t, 12H, CH3, diethyl ether); 2.4–2.0 (br,
6H, CH2); 1.3 (s, 3H, CH3)
7.5–7.1 (br,m, 60H, Ph); 2.2 (br, 12H, CH2); 1.2
(br,s, 6H, CH3)
7.65–7.2 (v.br,m 60H, Ph); 2.25 (br,m, 12H, CH2);
1.3 (s, 6H, CH3)
7.7–7.1 (v.br,m, 60H, Ph); 2.45–2.1 (br,m, 12H, CH2);
1.3 (s, 6H,CH3)
7.9–7.1 (v.br,m, 45H, Ph); 3.5 (q, 4H, CH2, diethyl
ether); 2.5 (t, 6H, CH3, diethyl ether); 2.3–1.9 (br,m,
6H, CH2); 1.1 (br,s, 3H, CH3)
7.7–7.25 (v.br,m, 45H, Ph); 2.15 (br,m, 6H, CH2); 1.2
(s, 3H, CH3)
7.8–7.0 (v.br,m, 45H, Ph); 2.4–1.9 (br,m, 6H, CH2);
1.35 (s, 3H, CH3)
7.25 (v.br,m, 45H, Ph); 2.6 (br,m, 6H, CH2); 1.38
(br,s, 3H, CH3)
7.7–7.1 (v.br,m, 45H, Ph); 2.65–2.2 (br,m, 6H, CH2);
1.6 (br,s, 3H, CH3)
7.7–7.1 (v.br,m, 45H, Ph); 2.5–1.9 (br,m, 6H, CH2);
1.25 (s, 3H, CH3)
8.0–6.9 (v.br,m, 30H, Ph); 3.8–3.5 (m, 6H, CH2); 1.3
(s, 9H, OCH3, phosphite); 1.1 (s, 3H, CH3)
7.7–7.0 (v.br,m, 30H, Ph); 4.2–4.0 (br,m, 6H, OCH2,
phosphite); 2.4–2.0 (v.br, 6H, CH2); 1.3 (t, 9H, CH3,
phosphite); 1.2 (s, 3H, CH3)
1971s, 1857s
2042s, 1971br, 1938s, 1845br
2074s, 2044s, 2005br, 1939s,
1844br
2074s, 2037s, 1963s, 1935s, 1908s,
1842br
2072s, 2035s, 2009s, 1959s, 1908s,
1838br
2074s, 2044s, 2023s, 1939vs,
1848br
2044s, 2027vs, 1966vs, 1937br,
1848br
2072s, 2028vs, 1967vs, 1940vs,
1899s, 1860s
2072s, 2036vs, 2019br, 1961br,
1910br, 1844s
2072vs, 2037s, 2017s, 1933br,
1910s, 1839br
2012s, 1934s, 1833br
2072s, 2037s, 1935s, 1839br
2072s, 2037s, 2007s, 1935s,
1840br
2035s, 1965s, 1939s, 1915s, 1840s
2044s, 1972m, 1940s, 1866br
2036vs, 1960vs, 1907vs, 1855s
2041s, 1973s, 1937s, 1861br
2037s, 1962s, 1907s
2046s, 2034s, 1980s, 1938s
2037s, 1960s, 1905s
2029s, 1977s, 1937br,s
2038s, 1961s, 1907br,s
7
8
–
–
–
–
–
–
–
9
6
7
8
9
10
11
12
13
10
11
12
13
14
15
16
14
15
16
–
–
–
17
18
19
20
21
22
23
24
25
–
–
–
–
–
1619w
1619w
1654w
1618w
Spectra recorded in CHCl3 as thin films between NaCl plates; br,
broad; s, strong; m, medium; vs, very strong; w, weak.
17
18
19
20
21
22
7.8–6.7 (v.br,m, 45H, Ph); 2.4–1.9 (br,m, 6H, CH2);
1.1 (s, 3H, CH3)
7.6–6.8 (v.br,m, 50H, Ph); 4.6 (br,m, 2H, CH2,
dppm); 2.3–1.9 (br,m, 6H, CH2); 1.25 (br,s, 3H, CH3)
7.6–7.1 (v.br,m, 50H, Ph); 4.6 (br,m, 2H, CH2,
dppm); 2.2 (br,m, 6H, CH2); 1.1 (s, 3H, CH3)
7.0–6.9 (br,m, 50H, Ph); 2.9–2.6 (br,m, 4H, CH2,
dppe); 2.1 (br,m, 6H, CH2); 1.25 (br,s, 3H, CH3)
7.7–7.1 (br,m, 50H, Ph); 2.9–2.1 (br,m, 4H, CH2,
dppe); 2.2 (br,m, 6H, CH2); 1.1 (s, 3H, CH3)
7.7–7.0 (v.br,m, 30H, Ph); 3.25 (q, 8H, hexyne);
2.4–2.0 (v.br,m, 6H, CH2, tripodal triphos); 1.25 (t,
6H, CH3, hexyne); 1.1 (s, 3H, CH3, tripodal triphos)
7.9–7.1 (v.br,m, 30H, Ph); 3.5–3.2 (q, 8H, CH2,
hexyne); 3.1–2.5 (v.br,m, 6H, CH2, tripodal triphos);
1.2 (t, 12H, CH3, hexyne); 1.1 (s, 3H, CH3, tripodal
triphos)
plex, [WI2(CO)3{PhP(CH2CH2PPh2)2ꢀP,P%}], which has
five carbonyl bands in its IR spectrum [30].
The 31P{1H}-NMR (CDCl3) spectra for the molybde-
num complex 1 at −50, 25 and 50 °C have been
investigated. At −50 °C, the spectrum shows a reso-
nance at −29.51 ppm due to the uncoordinated phos-
phorus atom, a single resonance at 16.67 ppm due to
the fluxional seven-coordinate unit, [MoI2(CO)3-
{MeC(CH2PPh2)3ꢀP,P%}]. At 25 °C, the 31P{1H}-NMR
(CDCl3) spectrum is similar, but the resonance for the
coordinated phosphorus atoms appears at l=12.63
ppm. It should be noted that the free ligand,
MeC(CH2PPh2)3, has a single resonance at l= −26.32
ppm in CDCl3 at 25 °C, and the resonance at l=
−29.51 ppm for the free phosphorus on 1 is, as ex-
pected, close to this value. Variable temperature
31P{1H}-NMR spectra in CDCl3 for complex 2 have
also been studied. At −50 °C there are two doublets
at l= −14.55 ppm and l= −25.21 ppm, (JPP=38.42
23
24
25
7.8–7.2 (v.br,m, 60H, Ph); 3.4 (q, 4H, CH2, hexyne);
2.4–2.1 (m, 12H, CH2, tripodal triphos); 1.2 (t, 6H,
CH3, hexyne); 1.1 (s, 6H, CH3, tripodal triphos)
7.8 (v.br,m, 60H, Ph); 3.5-3.1 (dq, 4H, CH2, hexyne);
2.5-2.1 (m, 12H, CH2, tripodal triphos); 1.25 (t, 6H,
CH3, hexyne), 1.1 (s, 6H, CH3, tripodal triphos)
Spectra recorded in CDCl3 (25 °C) and referenced to Me4Si; s,
singlet; br, broad; d, doublet; m, multiplet; t, triplet; q, quartet.

102
P.K. Baker et al. / Journal of Organometallic Chemistry 648 (2002) 99–108
Table 4
31P-NMR data (l)a for selected tripodal triphos {MeC(CH2PPh2)3} complexes of molybdenum(II) and tungsten(II)
Complex
31P-NMR data (l (ppm))
1
at −50 °C (tricarbonyl complex); 16.67 due to two coordinated P in MeC(CH2PPh2)3 atoms; −29.51 due to free P in
MeC(CH2PPh2)3, at 25 °C (tricarbonyl complex); 12.63 due to two coordinated P, MeC(CH2PPh2)3 atom and −29.51 due to
free P in MeC(CH2PPh2)3
2
at −50 °C (tricarbonyl complex); −14.55 (Jwp=219.7 Hz) and −25.21 (d, JPP=38.42 Hz) cis, due to the coordinated P in
MeC(CH2PPh2)3; −31.25 due to free uncoordinated P in MeC(CH2PPh2)3
17.82 {s, MeC(CH2PPh2)3 coordinated}
3
4
15.72 {s, MeC(CH2PPh2)3 (JPW=222.46 Hz)}
5
19.36 {s, 4P, MeC(CH2PPh2)3}; 24.99 {s, 2P, MeC(CH2PPh2)3}
6
17.45 {s, 4P, MeC(CH2PPh2)3}; 35.19 {s, 2P, MeC(CH2PPh2)3}
7
8
9
10
11
12
13
18
19
20
−12.38 {brs, 4P, MeC(CH2PPh2)3}; 32.61 {brs, 2P, MeC(CH2PPh2)3}
−15.83 {brs, 4P, MeC(CH2PPh2)3}; 28.77 {brs, 2P, MeC(CH2PPh2)3}
17.51 {s, 2P, MeC(CH2PPh2)3}; 29.85 {s, 1P, MeC(CH2PPh2)3}; 71.45 (s, 1P, PPh3)
17.51 {brs, 2P, MeC(CH2PPh2)3}; 41.14 {brs, 1P, MeC(CH2PPh2)3};
17.55 {brs, 2P, MeC(CH2PPh2)3}; 25.94 {brs, 1P, MeC(CH2PPh2)3}
−13.76 {brs, 2P, MeC(CH2PPh2)3}; 25.16 {brs, 1P, MeC(CH2PPh2)3}; 35.47 (s, PPh3)
−14.32 {br, 2P, MeC(CH2PPh2)3}; 34.20 {br, 1P, MeC(CH2PPh2)3}
−22.50 and −29.75 (s, dppm); 17.45 {s, 2P, MeC(CH2PPh2)3}; 39.45 {s, 1P, MeC(CH2PPh2)3
−29.62 and −36.19 {d, (JPP=53.56 Hz) dppm}; −14.41 {s, 2P, MeC(CH2PPh2)3}; 24.97 {s, 1P, MeC(CH2PPh2)3}
−15.93 and −30.64 {d, (JPP=51.87 Hz) dppe}; 17.52 {s, 2P, MeC(CH2PPh2)3}, (JPP=229.329 Hz); 25.63 {s, 1P,
MeC(CH2PPh2)3}
21
22
23
24
25
−13.16 {s, 2P, MeC(CH2PPh2)3}; 25.17 {s, 1P, MeC(CH2PPh2)3, (JPW=201.11 Hz)}; −17.16 and −29.50 (s, dppe)
17.56 {s, 2P, MeC(CH2PPh2)3}; 38.95 {s, 1P, MeC(CH2PPh2)3}
−12.63 {s, 2P, MeC(CH2PPh2)3}; 49.80 {s, 1P, MeC(CH2PPh2)3}
19.78 {s, 2P, MeC(CH2PPh2)3}; 25.34 {s, 1P, MeC(CH2PPh2)3}
−12.76 {s, 2P, MeC(CH2PPh2)3}; 46.68 {s, 1P, MeC(CH2PPh2)3}
a Spectra recorded in CDCl3 (25 °C) and referenced to H3PO4.
Hz), which can be assigned to the two coordinated
phosphorus atoms in different environments, with per-
haps one phosphorus atom trans to a carbonyl ligand,
groups are cis to each other (see Table 2). Larger scale
reactions of 1 and 2 in CHCl3 at 60 °C to give the
dicarbonyl complexes 3 and 4 are described in the
Section 3. It is interesting to note the reaction of chain
triphos {PhP(CH2CH2PPh2)2} [30], with [MI2(CO)3-
(NCMe)2] is much faster than with tripodal triphos to
eventually give the dicarbonyl complexes, [MI2(CO)2-
{PhP(CH2CH2PPh2)2ꢀP,P%,P¦}] and [MI2(CO)2{MeC-
(CH2PPh2)3ꢀP,P%,P¦}] (3 and 4), respectively. This may
be due to the ease of coordination of the third phos-
phorus atom in chain triphos compared with the more
restricted tripodal triphos ligand. For complex 3, the
reaction was totally completed in refluxing in CHCl3
for 15 h. Whereas, complex 4 gave the dicarbonyl
complex as a green powder, and very little of the
tricarbonyl complex after 72 h reflux. The dicarbonyl
and one trans to an iodide atom. The coupling JPP
=
38.42 Hz, can be assigned to the coordinated cis-phos-
phorus atoms, and JWP coupling for the resonance
at l= −14.55 ppm is 219.7 Hz. The resonance at
l= −31.25 ppm at −50 °C is likely to be due to the
uncoordinated phosphorus atom. Since the structure of
a wide range of seven-coordinate complexes of the type
[MX2(CO)3L2] have capped octahedral geometry
[28,29,35–37], it may be that the structure of 1 and 2
have the structure as shown in Fig. 1, in view of the
different environment of the phosphorus atoms ob-
served in the −50 °C 31P{1H}-NMR spectrum of 2.
Many unsuccessful attempts were made to grow suit-
able single crystals for X-ray analysis of 1 and 2.
The intramolecular reactions of [MI2(CO)3{MeC-
(CH2PPh2)3ꢀP,P%}] (1 and 2) in CHCl3 to give
[MI2(CO)2{MeC(CH2PPh2)3ꢀP,P%,P¦}] (3 and 4) were
followed by IR spectroscopy. The reactions of 1 and 2
in refluxing CHCl3 at 60 °C takes 15 h for 1 (M=Mo),
and 72 h for 2 (M=W) gives the dicarbonyl complexes
3 and mainly 4, respectively. The greater lability of
molybdenum complexes compared with their tungsten
analogues has been previously observed. Complexes 3
and 4 both have, as expected, two carbonyl bands in
their IR spectra, which suggests that the carbonyl
Fig. 1. The proposed structure of [MI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]
(1 and 2).

P.K. Baker et al. / Journal of Organometallic Chemistry 648 (2002) 99–108
103
crystallised out of solution very rapidly in NMR sol-
vents such as CDCl3 and CD2Cl2 at low temperature.
The rest of this paper describes the reactions of the
complexes [MI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] (1 and
2) as monodentate phosphine ligands, and are desig-
nated as LMo (complex 1) and LW (complex 2). A
summary of the reactions described is given in Scheme
1.
Fig. 2. The proposed structure of [MI2(CO)2{MeC(CH2PPh2)3ꢀ
P,P%,P¦}] (3 and 4).
2.2. Reactions of [MI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]
(1 and 2) with a series of molybdenum(II) and
tungsten(II) complexes
complexes 3 and 4 are considerably less soluble in
CH2Cl2 and CHCl3 than the tricarbonyl complexes 1
and 2. This may be due to the symmetrical nature of 3
and 4, which may pack well in the crystal lattice,
whereas the uncoordinated CH2PPh2 groups in 1 and 2
may inhibit symmetrical packing of the molecules in the
crystal lattice. The structure shows that all three phos-
phorus atoms of tripodal triphos in 3 and 4 are bonded
to the tungsten centre to give them greater stability
compared with 1 and 2. A proposed capped octahedral
structure [28,29,35–37], of 3 and 4 is shown in Fig. 2,
which conforms with the IR data (Table 2) and
31P{1H}-NMR data (Table 4).
Reaction of [MI2(CO)3(NCMe)2] (M=Mo or W)
with two equivalents of LMo or LW in CH2Cl2 at room
temperature yields the acetonitrile displaced trimetallic
complexes [MI2(CO)3(LMo or LW)2] (5–8). Complexes
5–8 have been fully characterised (see Tables 1–4).
Complex 5 (M=Mo, LMo) was confirmed as a bis(di-
ethyl ether) solvate by repeated elemental analyses and
1H-NMR spectroscopy. Attempts to obtain suitable
FAB mass spectra for 5–8 were unsuccessful, as no
parent ions were obtained, however, molecular weight
measurements by Rast’s method [38] (see Section 3)
give an indication that the complexes are trimetallic in
nature. The solubility of complexes 5–8 is less than 1
and 2, and the complexes are only moderately soluble
in CH2Cl2. They are of similar stability to 1 and 2, and
can be stored under nitrogen in the solid state for
several weeks without decomposition.
The room temperature 31P{1H}-NMR spectra
(CDCl3) of 3 and 4 both show one resonance for the
phosphorus atoms at l=17.82 and 15.72 ppm, respec-
tively. This suggests that the complexes are fluxional in
solution. It is much more likely they are fluxional, but
also due to poor solubility it was not possible to obtain
good low temperature NMR spectra, as the complexes
Scheme 1.

104
P.K. Baker et al. / Journal of Organometallic Chemistry 648 (2002) 99–108
(Table 1), IR (Table 2), 1H-NMR (Table 3) and in
selected cases by 31P{1H}-NMR spectroscopy (Table 4).
Complex 9 (M=Mo, L=PPh3, LMo) was confirmed as
a diethyl ether solvate by repeated elemental analyses
and 1H-NMR spectroscopy. Molecular weight measure-
ments by Rast’s method [38] (see Section 3) of selected
complexes suggest the bimetallic nature of these com-
plexes. The stability and solubility of complexes 9–17
are similar to the trimetallic complexes 5–8, with the
exception of the phosphite complexes 15–17, which are
considerably more soluble than 9–14, and slightly less
stable. The mechanism of these ligand displacement
reactions are likely to be dissociative, since both
[MI2(CO)3(NCMe)2] and [MI2(CO)3(NCMe)L] com-
plexes obey the effective atomic number rule.
Fig. 3. Proposed structure of [MI2(CO)3(LMo or LW)2] (5–8).
The IR spectra of 9–17 show a number of overlap-
ping bands, as for complexes 5–8 described above. For
example, complex 12 has bands at w(CO)=2036, 1961
and 1910 cm−1, which are likely to be due to the LW,
Fig. 4. Proposed structure of [MI2(CO)3L (LMo or LW)] {M=Mo or
W; L=PPh3, AsPh3, SbPh3, {for M=W only, P(OR)3 (R=Me, Et
or Ph)}} (9–17).
The IR spectra of 5–8 all show a number of carbonyl
bands, which are overlapping due to both the tricar-
bonyl centres, [MI2(CO)3L2], and the tricarbonyl com-
plexes, 1 and 2 attached to the central molybdenum or
tungsten centres. For example, complex 6 has five car-
bonyl bands at, w(CO)=2074, 2044, 2005, 1939 and
1844 cm−1. A number of unsuccessful attempts were
made to grow suitable single crystals of 5–8, however,
since the structure of [WI2(CO)3(NCMe)2] has been
crystallographically determined, and a structure of the
units of [MI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] have been
proposed (see Fig. 1), a possible structure for 5–8 is
shown in Fig. 3. The 31P{1H}-NMR (25 °C, CDCl3)
spectra for 5–8 show two resonances; one of them for
the two phosphorus atoms on one metal, and the other
resonance for the third phosphorus atom on the other
metal. Due to poor solubility of 5–8, it was difficult to
observe coupling constants in their 31P{1H}-NMR spec-
tra. For example, complex 5 has two resonances, one at
l=19.36 ppm, which is due to the same sets of two
phosphorus atoms on the fluxional Mo unit of
[MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] {see complex 1,
l=16.67 ppm}, and at l=24.99 ppm, which is due to
the phosphorus atoms bonded to the [MoI2(CO)3-
(LMo)2] centre. The resonance intensities for 5 at 19.36
and 24.99 ppm are in an ca. 2:1 ratio, which is in
accord with the structure of the complexes shown in
Fig. 3.
and bands at w(CO)=2072, 2019 and 1844 cm−1
,
which may be due to the [WI2(CO)3(PPh3)…] unit. The
31P{1H}-NMR spectra of the AsPh3 and SbPh3 com-
plexes show two different resonances due to tripodal
triphos ligand. For example, complex 13 has two reso-
nances; one at l= −14.32 ppm, which is due to the
two phosphorus atoms on the fluxional [WI2(CO)3-
{MeC(CH2PPh2)3ꢀP,P%}] unit, and one at l=34.20
ppm for the third phosphorus atom, which is attached
to the [WI2(CO)3(AsPh3)] unit. The resonances at l=
−14.32 and 34.20 ppm are in an ca. 2:1 intensity ratio.
A possible structure for complexes 9–17 is shown in
Fig. 4.
Reaction of equimolar quantities of [MI2(CO)3-
(NCMe)2] (M=Mo or W) and Ph2P(CH2)nPPh2 (n=1
or 2) in CH2Cl2 at room temperature affords the previ-
ously described [40] complexes [MI2(CO)3{Ph2P-
(CH2)nPPh2}], which react in situ with one equivalent
of LMo or LW to produce the cationic complexes
[MI(CO)3(LMo or LW){Ph2P(CH2)nPPh2}]I (18–21) in
high yield, which were characterised (Tables 1–4) in the
normal manner. Molecular weight studies by Rast’s
method [38], suggest the bimetallic nature of these
complexes. The IR spectrum of, for example, complex
18, has bands at 2044, 1972, 1940 and 1866 cm−1. It
may be that the bands at 1972, 1940 and 1866 cm−1 are
due to the [MoI(CO)3…] unit, and bands at 1972 and
1940 including another band at 2044 cm−1, are due to
LMo. The 31P{1H}-NMR spectra have, as expected, four
different resonances (see Table 4). For example, com-
plex 19 has a resonance at l= −14.41 ppm, which is
due to the two phosphorus atoms on the fluxional LW
unit, and at l=24.97 ppm due to the third phosphorus
atom attached to the [WI(CO)3(LW){Ph2P(CH2)PPh2}]I
centre. Also complex 19 has two doublets at l=
−29.62 and −36.19 ppm, due to the coordinated
dppm ligand. JPP coupling was often not observed in
Treatment of [MI2(CO)3(NCMe)2] with one equiva-
lent of L {L=PPh3, AsPh3, SbPh3; for M=W only,
P(OR)3 (R=Me, Et or Ph)} in CH2Cl2 at room tem-
perature gives the mono(acetonitrile) complexes
[MI2(CO)3(NCMe)L] [39], which react in situ with
equimolar amounts of LMo or LW to afford the new
mixed-ligand bimetallic complexes [MI2(CO)3L(LMo or
LW)] (M=Mo or W) (9–17). Complexes 9–17 have
been characterised by elemental analysis (C, H and N)

P.K. Baker et al. / Journal of Organometallic Chemistry 648 (2002) 99–108
105
the spectra due to poor solubility of the complexes in
CDCl3 and CD2Cl2. A possible structure for this com-
plex is shown in Fig. 5.
band at w(CO)(CHCl3)=2046 cm−1 for the [MoI2-
(CO)(h2-EtC2Et)2] part of the molecule. The IR spec-
trum of [WI2(CO)(NCMe)(h2-EtC2Et)2] has w(CO)=
2056 cm−1 in CHCl3 [41]. Since the structure of the
acetonitrile bis(alkyne) complexes, [WI2(CO)(NCMe)-
(h2-RC2R)2] (R=Me or Ph) has cis and parallel alkyne
molecules [42], then it is likely that the structure of 22
and 23 will have the acetonitrile replaced by LMo (22)
or LW (23), with retention of configuration as shown in
Fig. 6. The spectroscopic data for 22 and 23 conform
with this structure. The 31P{1H}-NMR spectrum of 22
has resonances at l=17.56 and 38.95 ppm due to the
[MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] unit, and the
[MoI2(CO)LMo(h2-EtC2Et)2] unit, respectively, in an ca.
2:1 intensity ratio. However, complexes 24 and 25 have
carbonyl bands due to LMo or LW, and bands due to
the [MI2(CO)(h2-EtC2Et)] unit. For example, the IR
spectrum of complex 24 has bands at w(CO)=2029,
1977 and 1937 cm−1, due to the LMo unit, and the
broad band at 1937 cm−1 due to the [MoI2(CO)(h2-
EtC2Et)] unit. The IR spectrum of [WI2(CO)(PPh3)2(h2-
EtC2Et)] has w(CO)=1942 cm−1 in CHCl3 [41].
The bis(3-hexyne) complexes [MI2(CO)(NCMe)(h2-
EtC2Et)2] (M=Mo or W) [41] were prepared by react-
ing the seven-coordinate complexes [MI2(CO)3-
(NCMe)2] with two equivalents of 3-hexyne. Equimolar
quantities of LMo or LW and [MI2(CO)(NCMe)(h2-
EtC2Et)2] react in CH2Cl2 at room temperature to give
the bis(3-hexyne) complexes, [MI2(CO)(LMo or LW)(h2-
EtC2Et)2] {M=Mo, LMo (22); M=W, LW (23)}.
Whereas, two equivalents of LMo or LW react in CH2Cl2
at room temperature with one equivalent of [MI2(CO)-
(NCMe)(h2-EtC2Et)2] to give the mono(3-hexyne) com-
plexes, [MI2(CO)(LMo or LW)2(h2-EtC2Et)] {M=Mo,
LMo (24); M=W, LW (25)} in high yield. Complexes
22–25 have been fully characterised in the normal
manner (see Tables 1–4).
The IR spectrum of, for example, complex 22 shows
four carbonyl bands; three of them at w(CO)(CHCl3)=
2034, 1980 and 1938 cm−1, for the LMo unit, and one
The room temperature 31P{1H}-NMR spectra for
complexes 24 and 25 show two resonances for the
tripodal phosphorus coordinated to LMo or LW. For
example, complex 24 has a resonance at l=19.78 ppm
due to the two phosphorus atoms on the fluxional LMo
centre, and at l=25.34 ppm for the third phosphorus
atom coordinated to the [MoI2(CO)(h2-EtC2Et)] unit in
an ca. 2:1 intensity ratio. It is very likely that the
structures of 24 and 25 have trans LMo and LW ligands
in their respective complexes as shown in Fig. 7. This
conforms with the spectroscopic properties of these
complexes. The 3-hexyne ligand makes these complexes
more soluble than their starting materials, 1 and 2.
Several unsuccessful attempts were made to grow single
crystals for X-ray analysis of 22–25.
Fig. 5. Proposed structure of [MI(CO)3]{Ph2P(CH2)nPPh2}]I (LMo or
LW) (18–21).
In conclusion, tripodal triphos {MeC(CH2PPh2)3},
reacts with the seven-coordinate complexes, [MI2(CO)3-
(NCMe)2] to give [MI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]
(1 and 2). The tricarbonyl complexes [MI2(CO)3-
{MeC(CH2PPh2)3ꢀP,P%}] (1) and (2) eventually react
intramolecularly to give the dicarbonyl complexes,
[MI2(CO)2{MeC(CH2PPh2)3ꢀP,P%,P¦}] (3) and (4), re-
spectively. The monodentate phosphine ligands,
[MI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] (1) and (2) react
with a wide range of complexes of molybdenum(II) and
tungsten(II) to give a number of new, fully character-
ised multimetallic complexes as shown in Scheme 1.
Fig. 6. Proposed structure of [MI2(CO)(LMo or LW)(h2-EtC2Et)2] (22
and 23).
3. Experimental
3.1. Reagents and general techniques
Fig. 7. Proposed structure of [MI2(CO)(LMo or LW)2(h2-EtC2Et)] (24
and 25).
All reactions were carried out under an atmosphere
of dry nitrogen using standard vacuum/Schlenk line

106
P.K. Baker et al. / Journal of Organometallic Chemistry 648 (2002) 99–108
techniques. The starting materials [MI2(CO)3(NCMe)2]
(M=Mo or W) [27], [MI2(CO)3(NCMe)L] [39],
[MI2(CO)3{Ph2P(CH2)nPPh2}] (n=1 or 2) [40],
[MI2(CO)(NCMe)(h2-EtC2Et)2] [41] were prepared by
published methods. CH2Cl2 and Et2O were dried and
distilled before use. All chemicals were obtained from
commercial sources.
3.4. Preparation of [MoI2(CO)3{v-MoI2(CO)3-
{MeC(CH2PPh2)3}ꢀP,P%}2] (5)
To a stirred solution of [MoI2(CO)3(NCMe)2] (0.15 g,
0.26 mmol) in CH2Cl2 (20 cm3) was added
[MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] (1) (0.54 g, 0.51
mmol). Filtration and removal of solvent in vacuo after
24 h, gave the brown crystalline powder, [MoI2(CO)3[m-
MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]2] (5), which was
recrystallised from CH2Cl2–Et2O at −17 °C. Yield of
pure product 0.65 g (87%). Molecular weight: Complex
5 requires, 2550; found, 2667.
Elemental analyses (carbon, hydrogen and nitrogen)
were determined using a Carlo Erba Elemental Analy-
ser MOD 1108 (using helium as a carrier gas). IR
spectra were recorded as CHCl3 films between NaCl
plates on a Perkin–Elmer 1600 series FTIR spec-
1
trophotometer, H- (referenced to SiMe4) and 31P{1H}-
Similar reactions of [MI2(CO)3(NCMe)2] with two
(referenced to 85% H3PO4) NMR spectra on a Bruker
AC 250 MHz NMR spectrometer. Molecular weights
were determined using Rast’s method [38] using cam-
phor as the standard.
equivalents of L {L=[MI2(CO)3{MeC(CH2PPh2)3ꢀ
P,P%}] {M=W, L=LMo or LW}; {M=Mo, L=LW}
in CH2Cl2 at r.t., after 24 h gave the complexes,
[MI2(CO)2(LMo or LW)2] (6–8). For physical and ana-
lytical data see Table 1. Molecular weights: Complex 6
requires, 2638; found, 2220. Complex 7 requires, 2726;
found, 2667.
3.2. Preparation of
[MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] (1)
3.5. Preparation of [MoI2(CO)3(PPh3)[v-MoI2(CO)3-
{MeC(CH2PPh2)3-P,P%}]I (9)
To a stirred solution of [MoI2(CO)3(NCMe)2] (0.50 g,
0.97 mmol) in CH2Cl2 (20 cm3) at 0 °C was added
1,1,1-tris(diphenylphosphinomethyl)ethane,
To a stirred solution of [MoI2(CO)3(NCMe)2] (0.3 g,
0.58 mmol) in CH2Cl2 (20 cm3) at r.t. was added PPh3
(0.15 g, 0.57 mmol), and left to stir for 1 min. To this
was added [MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] (0.62
g, 0.58 mmol). Filtration and removal of solvent in
vacuo after 24 h, gave the brown crystalline powder
of [MoI2(CO)3(PPh3)[m-MoI2(CO)3{MeC(CH2PPh2)3ꢀ
P,P%}]] (9), which was recrystallised from CH2Cl2–Et2O
at −17 °C. Yield of pure product 0.92 g (90%).
Similar reactions of [MI2(CO)3(NCMe)2] with one
equivalent of L {L=PPh3 (1 min), AsPh3 (3 min),
SbPh3 (5 min), P(OR)3 (1 min)}, in CH2Cl2 at r.t., and
then followed by LW or LMo {M=Mo, L%=LMo),
L=AsPh3 (10), L=SbPh3 (11), {M=W, LW, L=
PPh3 (12), L=AsPh3 (13), L=SbPh3 (14), L=
P(OMe)3 (15), R=P(OMe)3 (16), R=P(OPh)3 (17)},
gave the complexes, [MI2(CO)3(L)(LMo or LW)] (10–
17). For physical and analytical data see Table 1.
Molecular weights: Complex 10 requires, 1796; found,
1330. Complex 11 requires, 1845; found, 1429. Complex
12 requires, 1930; found, 2000. Complex 16 re-
quires,1834; found, 2010.
MeC(CH2PPh2)3 (0.607 g, 0.97 mmol). After stirring for
5 min, filtration and removal of solvent in vacuo, gave
the brown crystalline powder of [MoI2(CO)3{MeC-
(CH2PPh2)3ꢀP,P%}] (1), which was recrystallised from
CH2Cl2–Et2O at −17 °C. Yield of pure product 0.82 g
(80%). Molecular weight: Complex 1 requires, 1058;
found, 1142.
A similar reaction of [WI2(CO)3(NCMe)2] with one
equivalent of L {L=MeC(CH2PPh2)3} in CH2Cl2 at
room temperature (r.t.) for 5 min gave the complex,
[WI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] (2). Molecular
weight: Complex 2 requires, 1146; found, 1330. For
physical and analytical data see Table 1.
3.3. Preparation of
[MoI2(CO)2{MeC(CH2PPh2)3ꢀP,P%,P¦}] (3)
To a stirred solution of [MoI2(CO)3(NCMe)2] (0.25 g,
0.48 mmol) in refluxing CHCl3 (20 cm3) at 60 °C was
added MeC(CH2PPh2)3 (0.30 g, 0.48 mmol). After
refluxing for 15 h, filtration and removal of solvent in
vacuo, gave the brown crystalline powder,
[MoI2(CO)2{MeC(CH2PPh2)3ꢀP,P%,P¦}] (3), which was
recrystallised from CHCl3–Et2O at −17 °C. Yield of
pure product 0.33 g (66%). Molecular weight: Complex
3 requires, 1030; found, 1143.
A similar reaction of [WI2(CO)3(NCMe)2] with one
equivalent of L {L=MeC(CH2PPh2)3} in refluxing
CHCl3 at 60 °C, for 72 h gave mainly the dicarbonyl
complex, [WI2(CO)2{MeC(CH2PPh2)3ꢀP,P%,P¦}] (4).
For physical and analytical data see Table 1.
3.6. Preparation of [MoI(CO)3{Ph2P(CH2)PPh2}-
[v-MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]I (18)
To a stirred solution of [MoI2(CO)3(NCMe)2] (0.2 g,
0.39 mmol) in CH2Cl2 (20 cm3) at r.t. was added dppm
(0.15 g, 0.39 mmol), and stirred for 20 min. To this
solution was added [MoI2(CO)3{MeC(CH2PPh2)3ꢀ
P,P%}] (0.41 g, 0.38 mmol). Filtration and removal of
solvent in vacuo after 24 h, gave the brown crystalline

P.K. Baker et al. / Journal of Organometallic Chemistry 648 (2002) 99–108
107
powder of [MoI(CO)3{Ph2P(CH2)PPh2}[m-MoI2(CO)3-
References
{MeC(CH2PPh2)3ꢀP,P%}]]I (18), which was recrys-
tallised from CH2Cl2–Et2O at −17 °C. Yield of pure
product 0.47 g (64%).
[1] B.F. Hoskins, R.J. Steen, T.W. Turney, Inorg. Chim. Acta 77
(1983) L69.
[2] J.G. Toerien, P.H. van Rooyen, J. Chem. Soc. Dalton Trans.
(1991) 2693.
[3] F.S. Hassan, D.P. Markham, P.G. Pringle, B.L. Shaw, J. Chem.
Soc. Dalton Trans. (1985) 279.
[4] H.-K. Yip, T.-F. Lai, C.-M. Che, J. Chem. Soc. Dalton Trans.
(1991) 1639.
[5] R.J. Puddephatt, M.A. Thomson, L. Manojlovic´-Muir, K.W.
Muir, A.A. Frew, M.P. Brown, J. Chem. Soc. Chem. Commun.
(1981) 805.
[6] C.-S. Chin, M.S. Sennett, P.J. Weir, L. Vaska, Inorg. Chim.
Acta 31 (1978) L443.
Similar reactions of [MI2(CO)3(NCMe)2] with one
equivalent of Ph2P(CH2)nPPh2, followed by (L=LW or
LMo) {M=W, L=LW), n=1 (19), n=2 (20); {M=
Mo, L=LMo, n=2 (21)} in CH2Cl2 at r.t. gave the
complexes, [MI(CO)3{Ph2P(CH2)nPPh2} (LMo or LW)]I
(n=1 or 2) (19–21). For physical and analytical data
see Table 1. Molecular weight: Complex 21 requires,
2193; found, 2000.
[7] E.W. Stern, P.K. Maples, J. Catal. 27 (1972) 120.
[8] L. Manojlovic´-Muir, K.W. Muir, M.C. Grossel, M.P. Brown,
C.D. Nelson, A. Yavari, E. Kallas, R.P. Moulding, K.R. Sed-
don, J. Chem. Soc. Dalton Trans. (1986) 1955.
[9] L. Manojlovic´-Muir, K.W. Muir, J. Chem. Soc. Chem. Com-
mun. (1982) 1155.
[10] C.T. Hunt, A.L. Balch, Inorg. Chem. 20 (1981) 2267.
[11] A.L. Balch, C.T. Hunt, C.-L. Lee, M.M. Olmstead, J.P. Farr, J.
Am. Chem. Soc. 103 (1981) 3764.
[12] P.G. Pringle, B.L. Shaw, J. Chem. Soc. Chem. Commun. (1982)
1313.
[13] F.S.M. Hassan, D.M. McEwan, P.G. Pringle, B.L. Shaw, J.
Chem. Soc. Dalton Trans. (1985) 1501.
[14] A.T. Hutton, P.G. Pringle, B.L. Shaw, J. Chem. Soc. Dalton
Trans. (1985) 1677.
[15] P.G. Pringle, B.L. Shaw, J. Chem. Soc. Chem. Commun. (1982)
956.
[16] B. Mohr, E.E. Brooks, N. Rath, E. Deutsch, Inorg. Chem. 30
(1991) 4541.
[17] N. Marsich, A. Camus, G. Nardin, J. Organomet. Chem. 239
(1982) 429.
3.7. Preparation of [MoI2(CO)[v-MoI2(CO)3-
{MeC(CH2PPh2)3ꢀP,P%}](p2-EtC2Et)2] (22)
To a stirred solution of [MoI2(CO)(NCMe)(h2-
EtC2Et)2] (0.25 g, 0.43 mmol) in CH2Cl2 (20 cm3) at r.t.
was added [MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}] (0.45
g, 0.42 mmol). Filtration and removal of solvent in
vacuo after 24 h, gave the brown crystalline powder
[MoI2(CO)[m - MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}](h2-
EtC2Et)2] (22), which was recrystallised from CH2Cl2–
Et2O at −17 °C. Yield of pure product 0.42 g (65%).
Molecular weight: Complex 22 requires, 1600; found,
1600.
A similar reaction of [WI2(CO)(NCMe)(h2-EtC2Et)2]
with one equivalent of LW in CH2Cl2 gave
[WI2(CO)(LW)(h2-EtC2Et)2] (23). For physical and ana-
lytical data see Table 1.
[18] A.M.M. Lanfredi, F. Ugozzoli, A. Camus, N. Marsich, R.
Capelletti, Inorg. Chim. Acta 206 (1993) 173.
[19] J.T. Mague, Inorg. Chem. 33 (1994) 4261.
[20] J. Die´z, M.P. Gamasa, J. Gimeno, A. Tiripicchio, M.T.
Camellini, J. Chem. Soc. Dalton Trans. (1987) 1275.
[21] D.M. Ho, R. Bau, Inorg. Chem. 22 (1983) 4073.
[22] H. Schmidbaur, A. Wohlleben, F. Wagner, O. Orama, G. Hu¨t-
tner, Chem. Ber. 110 (1977) 1748.
[23] X. Hong, K.-K. Cheung, C.-X. Guo, C.-M. Che, J. Chem. Soc.
Dalton Trans. (1994) 1867.
[24] L.-K. Liu, L.-S. Luh, Y.-S. Wen, U.B. Eke, M.A. Mesubi,
Organometallics 14 (1995) 4474.
[25] D.-N. Horng, S.-T. Jeng, C.-H. Ueng, J. Chin. Chem. Soc. 41
(1994) 539.
[26] D.-N. Horng, C.-H. Ueng, Inorg. Chim. Acta 232 (1995) 175.
[27] P.K. Baker, S.G. Fraser, E.M. Keys, J. Organomet. Chem. 309
(1986) 319.
3.8. Preparation of [MoI2(CO)[v-MoI2-
(CO)3{MeC(CH2PPh2)3ꢀP,P%}]2(p2-EtC2Et)] (24)
To a stirred solution of [MoI2(CO)(NCMe)(h2-
EtC2Et)2] (0.125 g, 0.21 mmol) in CH2Cl2 (20 cm3) at
r.t. was added [MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]
(0.45 g, 0.42 mmol). Filtration and removal of solvent
in vacuo after 24 h, gave the brown crystalline powder
[MoI2(CO)[m - MoI2(CO)3{MeC(CH2PPh2)3ꢀP,P%}]2(h2-
EtC2Et)] (24), which was recrystallised from CH2Cl2–
Et2O at −17 °C. Yield of pure product 0.45g (73%).
A similar reaction of [WI2(CO)(NCMe)(h2-EtC2Et)2]
with two equivalents of LW in CH2Cl2 gave
[WI2(CO)(LW)2(h2-EtC2Et)] (25). For physical and ana-
lytical data see Table 1. Molecular weight: Complex 25
requires, 2840; found, 2650.
[28] P.K. Baker, Adv. Organomet. Chem. 40 (1996) 45, and refs.
therein.
[29] P.K. Baker, Chem. Soc. Rev. 27 (1998) 125, and refs. therein.
[30] P.K. Baker, D. Sherlock, Polyhedron 13 (1994) 525.
[31] P.K. Baker, S.J. Coles, D.E. Hibbs, M.M. Meehan, M.B. Hurst-
house, J. Chem. Soc. Dalton Trans. (1996) 3995.
[32] P.K. Baker, M.G.B. Drew, M.M. Meehan, J. Szewczyk, J.
Organomet. Chem. 580 (1999) 265.
[33] P.K. Baker, M.M. Meehan, J. Organomet. Chem. 582 (1999)
259.
[34] P.K. Baker, M.M. Meehan, Inorg. Chim. Acta 303 (2000) 17.
[35] M.G.B. Drew, Prog. Inorg. Chem. 23 (1977) 67, and refs.
therein.
Acknowledgements
M.M.M. thanks the E.P.S.R.C. for a studentship.
M.Al-J. thanks the Saudi Arabian Government for
supporting him on a Ph.D. studentship.

108
P.K. Baker et al. / Journal of Organometallic Chemistry 648 (2002) 99–108
[36] M. Meln´ik, P. Sharrock, Coord. Chem. Rev. 65 (1985) 49, and
refs. therein.
[37] C.W. Haigh, P.K. Baker, Polyhedron 13 (1994) 417, and refs.
therein.
[39] P.K. Baker, S.G. Fraser, Transition-Met. Chem. 12 (1987) 560.
[40] P.K. Baker, S.G. Fraser, Inorg. Chim. Acta 130 (1987) 61.
[41] M. Al-Jahdali, P.K. Baker, M.G.B. Drew, Z. Naturforsch. Sect.
B 54 (1999) 171.
[38] F.G. Mann, B.L. Saunders, Practical Organic Chemistry, Long-
man’s Green, London, 1954, pp. 342–344.
[42] E.M. Armstrong, P.K. Baker, M.G.B. Drew, Organometallics 7
(1988) 319.