Dichloro and alkylchloro gallium derivatives of dichalcogenoimidodiphosphinate ligands: Isolation of a spirogallium cation

Article abstract of DOI:10.1039/b412874e

Dichloro and chloromethyl Ga(III) complexes of general formulae [XClGa-η²-{R₂P(E)NP(E′)R′ ₂-E,E′}] (X = Cl, R, R′ = Ph, E, E′ = O (1), S (2), Se (3); R = Ph, R′ = OEt, E = O, E′ = S (4); R = Me, R′ = Ph, E, E′ = S (5) and

Full text of DOI:10.1039/b412874e

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F U L L P A P E R
Dichloro and alkylchloro gallium derivatives of
dichalcogenoimidodiphosphinate ligands: isolation
of a spirogallium cation
a
a
a
´
Miguel-Angel Mun˜oz-Herna´ndez,* Virginia Montiel-Palma, Estefan´ıa Huitro´n-Rattinger,
Sara Corte´s-Llamas,a Norma Tiempos-Flores,a Jean-Michel Grevy,a Cristian Silvestrub and
Philip Powerc
a Centro de Investigaciones Qu´ımicas, Universidad Auto´noma del Estado de Morelos, Av.
Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos, 62210, Me´xico.
E-mail: mamund2@buzon.uaem.mx; Fax: (52) 777 3297997; Tel: (52) 777 3297997
b Facultatea de Chimie si Inginerie Chimica, Universitatea Babes-Bolyai, RO-3400,
Cluj-Napoca, Romania
c Department of Chemistry, University of California, Davis, One Shields Ave., Davis, CA 95616,
USA
Received 20th August 2004, Accepted 29th October 2004
First published as an Advance Article on the web 17th November 2004
2
Dichloro and chloromethyl Ga(III) complexes of general formulae [XClGa-g -{R2P(E)NP(Eꢀ)Rꢀ2-E,Eꢀ}] (X = Cl, R,
Rꢀ = Ph, E, Eꢀ = O (1), S (2), Se (3); R = Ph, Rꢀ = OEt, E = O, Eꢀ = S (4); R = Me, Rꢀ = Ph, E, Eꢀ = S (5) and X =
Me, E, Eꢀ = O (6), S (7), Se (8)) were synthesised by either metathesis reactions between GaCl3 and the potassium salt
of the ligand (X = Cl) or by methane eliminations from in situ prepared GaMe2Cl and the protonated ligands LH
(X = Me). Redistribution reaction of 3 in either CDCl3 or THF afforded the solvent-free tetracoordinate gallium
2
spirocycle cation [Ga-{g -{Ph2P(Se)NP(Se)Ph2-Se,Seꢀ})2]+ (9+). The molecular structures of complexes 2, 4, 5, 7 and
9+ show non-planar gallacycle rings.
Herein we report the synthesis, characterization and reactivity
Introduction
of dichloro and chloromethyl Ga species derived from EPNPEꢀ
The development of highly reactive main group polymeriza-
ligands. We show that in solution selenium dichloro derivatives
tion catalysts as lower-cost alternatives to transition metals
undergo redistribution reactions to generate a solvent-free, four-
has stimulated a considerable amount of work on group 13
coordinate Ga(III) spirocycle cation.
complexes.1 In particular, group 13 cationic complexes posses
enhanced Lewis acidity and can act as activators or catalysts in
reactions otherwise unaltered by the neutral species.2–8 However,
only a handful of these cations have been structurally and
spectroscopically characterised. It is generally accepted that the
catalytic activity of aluminium cations depends on their coor-
dination number. Indeed, five- and six-coordinate compounds
with Salen-type ligands have been demonstrated to be efficient
Results and discussion
Synthesis and spectroscopy of dichloro and chloromethyl gallium
compounds
catalysts for ring-opening polymerization and oligomerization
of substrates that bear Lewis basic atoms.5,9 On the other
hand, two-, three- and four-coordinate aluminium compounds
play a major role in the polymerization of olefins.2,3,10,11 Vis-
a`-vis to their Al analogues, Ga cations are considerably less
Lewis acidic and reactive and hence are particularly suitable
for detailed studies. Indeed, Wehmschulte’s two-coordinate
bisterphenyl Ga(III) cation,12 shows a Ga atom in an essentially
undistorted linear array (175.7(1)◦) by comparison with the bent
two-coordinate alumenium cation Et2Al+ isolated by Reed and
co-workers13 with the use of carborane anions CB11H6X6 (X =
Cl, Br). The latter compounds exhibit weak Al · · · X interactions
which decrease C–Al–C bond angles from the expected 180◦ to
136.6◦ (X = Cl) or 130.0◦ (X = Br).
Metathesis reactions between equimolar amounts of GaCl3 and
KL salts (L = [R2P(E)NP(Eꢀ)Rꢀ2]−) in methylene dichloride
2
resulted in the formation of the dichloro complexes [Cl2Ga-g -
{R2P(E)NP(Eꢀ)Rꢀ2-E,Eꢀ}] (R, Rꢀ = Ph, E, Eꢀ = O (1), S (2), Se
(3); R = Ph, Rꢀ = OEt, E = O, Eꢀ = S (4) and R = Me, Rꢀ = Ph,
E, Eꢀ = S (5)) [eqn. (1)].
In our search for robust and stable ring backbones to stabilize
Al and Ga ring heterocycles, we have been employing chelating
dichalocogenoimidophosphinate (EPNPEꢀ) ligands whose com-
pounds may undergo substitution reactions without degradation
of the original skeletal ring structure.14,15 Furthermore, their
wide bite angles (around 110◦) help stabilise labile metal cations.
In this regard Jordan and co-workers have demonstrated that
the lability of three-coordinate aluminium complexes is greatly
reduced with the use of large bite-angle ligands, as in the
amidinate systems [{RC(NRꢀ)2}AlMe]+.16
(1)
2
On the other hand, chloromethyl complexes [MeClGa-g -
{Ph2P(E)NP(Eꢀ)Ph2-E,Eꢀ}] (E, Eꢀ = O (6), S (7), Se (8)), were syn-
thesised by methane elimination reactions from in situ prepared
GaMe2Cl and the protonated LH ligands {R2P(E)NHP(Eꢀ)Rꢀ2},
[eqn. (2)].
T h i s j o u r n a l i s
T h e R o y a l S o c i e t y o f C h e m i s t r y 2 0 0 5
D a l t o n T r a n s . , 2 0 0 5 , 1 9 3 – 1 9 9
1 9 3
©

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1
Table 1 Comparison of 31P{ H} NMR data in CDCl3 of [Cl2GaL] complexes 1–5 and [ClMeGaL] complexes 6–8 with literature data of compounds
of formulae [Me2GaL],15 free acidic ligands LH and potassium salts KL
Complex of the type
[Cl2GaL]
Complex of the type
[ClMeGaL]
Complex of the type
[Me2GaL]
Free acidic ligand LH
Potassium salt KL
1, 33.8 (s)
6, 29.9 (s)
26.4 (s)15,a
19.4 (s)20,c
10.5 (s)21
2, 38.2 (s)
7, 37.8 (s)
36.7 (s)15,b
55.7 (s)22,c
35.8 (s)22
3, 33.7 (s, 1JPSe 447 Hz)
4, 35.0 (d, 2JPP 24.4 Hz, PS);
2.9 (d, 2JPP 24.4 Hz, PO)
8, 31.7 (s, 1JPSe 485 Hz)
29.3 (s, 1JPSe 534 Hz)15,c
53.2 (s, 1JPSe 786 Hz)23,b
53.2 (d, 2JPP 8.2 Hz, PS); 1.3
(d, 2JPP 8.2 Hz, PO)24,b
28.5 (s, 1JPSe 687 Hz)23,d
KL.H2O: 37.3 (d, 2JPP
20.6 Hz, PS); 5.3 (d,
2JPP 20.6 Hz, PO)24,b
44.2 (d, 2JPP 13.7 Hz,
PMe2), 38.0 (d, 2JPP
13.7 Hz, PPh2)26,d
5, 44.0 (br, PMe2); 36.5 (d,
2JPP 14.1 Hz, PPh2)
63.9 (d, 2JPP 22.8 Hz, PMe2);
51.3 (d, 2JPP 22.8 Hz, PPh2)25,b
a C6D6. b CDCl3. c [D6]-THF. d CD3OD.
than those in the corresponding potassium salts KL and in the
free acidic ligands LH.
X-Ray crystallographic analysis of 2, 4, 5 and 7
Relevant crystal data for dichloro 2, 4 and 5 and chloromethyl 7
complexes (Figs. 1–4) are summarised in Table 4 and important
bond lengths and angles are contained in Table 2. In all cases, the
X-ray study show non-planar six-membered gallacycles adopt-
ing different conformations. Non-planar rings are commonly
(2)
A discrete number of dichloro17 and chloromethyl18 Ga
complexes have been reported, nonetheless compounds 1–8
represent the first examples of Ga species bearing EPNPEꢀ-type
ligands apart from a handful of dialkyl gallium complexes.14,15,19
The characterization of the complexes was achieved by
physical (mp), chemical (C, H and N analysis) and spectro-
scopic techniques (multinuclear NMR and IR spectroscopy) in
conjunction with single crystal X-ray diffraction determinations
of complexes 2, 4, 5 and 7.
The H, 13C{ H} and 31P{ H} NMR spectra of the prod-
ucts in CDCl3 were consistent with coordination of the
dichalcogenoimidodiphosphinate ligands to the Ga centres
resulting in C2v symmetric ring structures of compounds 1–3 and
1
1
1
1
Cs in 4–8. In the H NMR spectra of chloromethyl complexes
6–8, the Ga–methyl resonances appeared as singlets between 0.0
1
and 0.1 ppm. Due to metal coordination, the 31P{ H} NMR
spectra of chloromethyl complexes 7 and 8 showed a highfield
shift of the resonance signals with respect to the free protonated
ligands LH20 (Table 1). Along the series [Cl2GaL], [ClMeGaL]
and [Me2GaL]14,15 the 31P{ H} signals also showed a small but
1JPSe of selenium derivatives 3 and 8 were significantly smaller
1
consistent highfield shift. The values of the coupling constants
Fig. 2 Molecular structure of 4 with thermal ellipsoids shown at 30%
probability level.
Fig. 1 Molecular structure of 2 with thermal ellipsoids shown at 50% probability level.
D a l t o n T r a n s . , 2 0 0 5 , 1 9 3 – 1 9 9
1 9 4

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20
˚
=
1.69 A) in which there is not P N character. These results are
in agreement with the proposed structures.
The Ga–Cl bonds in 2, 4 and 5 are somewhat elon-
gated with respect to the corresponding ones in tetraco-
28
˚
ordinate (GaMeCl2)2 at 2.129(3) A, GaCl2(acac) (acac =
˚
2,4-pentanedionato) at 2.115(6) A and GaCl2(tmhd) (2,2,6,6-
tetramethylheptanedionato)17 at 2.124(2) A and are more similar
˚
29
˚
to those in tricoordinate (2,6-Mes2C6H3)2GaCl at 2.177 (5) A.
In particular, comparison of dichloro compound 2 with
2
its dimethyl analogue [Me2Ga-g -{Ph2P(S)NP(S)Ph2-S,Sꢀ}]15
allows interesting deductions. The Ga–Cl distances are longer
than the Ga–C distances (Table 3), as expected from the larger
radius of Cl and the higher electronegativity and higher tendency
of Cl to occupy Ga hybrid orbitals with higher p-character.
Furthermore, the Ga–S distances are shorter in 2 than in the
dimethyl species as a result of the greater d+ charge on Ga due
to Cl substitution. Other consequence of the replacement of CH3
for Cl is reflected in a larger S–Ga–S bond angle in 2 (ca. 12◦).
Meanwhile, the Cl–Ga–Cl angle in 2 is narrowed by ca. 16◦ than
the C–Ga–C angle. A similar effect has been noticed by Jordan
and co-workers in dichloro and dialkyl amidinate Al complexes30
and goes against a predicted larger Cl–Al–Cl angle compared
to C–Al–C on the basis of the cone angles Al–Cl (56.3◦) and
Al–CH3 (51◦). Jordan explains this apparent discrepancy also
in terms of Al–Cl bonding electron pair being smaller than the
Al–CH3 boding electron pair and on the higher p-character of
Al orbitals used to bind more electronegative Cl atoms.
Fig. 3 Molecular structure of 5 with thermal ellipsoids shown at 50%
probability level.
obtained in complexes derived from dichalcogenoimidodiphos-
phinate ligands as demonstrated by the variety of examples
encountered in main group and transition metal chemistry.20 The
metallacycle ring in symmetrically substituted disulfur complex
2 adopts a boat conformation with the Ga and N(1) atoms
at the apices of the boat. Unsymmetrically substituted disulfur
complex 5 is a chair with apices Ga and N(1). Mixed oxygen–
sulfur compound 4 is an envelope with Ga out of the plane
and chloromethyl disulfur 7 is a boat with S(1) and P(2) at the
apices. On this basis, no structural pattern for variation can be
predicted, nor can it be found when compared to other EPNPEꢀ
organogallium derivatives.14,15,19
In general, the Cl–Ga–Cl angles in 2, 4 and 5 show little
distortion from the ideal tetrahedral geometry. Nevertheless, the
Cl–Ga–Cl angles are smaller than in GaCl2(acac) (116.1(3)◦) and
in GaCl2(tmhd) (113.2(1)◦)17 as a result of a larger ligand cone
angle. Interestingly, the Ga–Cl distances in the dimethyldiphenyl
˚
complex 5 (2.176(1) and 2.177(1) A) are identical within exper-
imental error while the equivalent distances in the tetraphenyl
˚
compound 2 (2.163(1) and 2.175(1) A) show a bigger difference.
This behaviour could perhaps be attributed to the adoption of
different conformations of the metallacycle rings (vide supra).
In chloromethyl complex 7, both the Ga–S bond distances and
the Cl–Ga–C bond angles are of intermediate values between 2
and the dimethyl analogue (Table 3). Besides the Ga–Cl and
Ga–C bond distances are smaller than in either the dichloro and
dimethyl species.
Pure monomeric heavier group 13 element compounds with
two or three different ligands are scarce due to ligand re-
distribution reactions amongst heteroleptic species.17 Indeed,
Comparison of the P–E, P–Eꢀ and P–N bond lengths in the
complexes to those in the free acidic ligands suggests changes
in bond orders. Indeed, the P–S bond distances 2.060(2) and
˚
˚
˚
2.047(2) A in 2, 2.057(2) A in 4, 2.059(1) and 2.054(1) A in 5,
˚
and 2.034(2) and 2.027(2) A in 7 are elongated with respect to
˚
=
uncomplexed P S units (1.89–1.96 A) and indicate a lower bond
order.27 On the contrary, the P–N bond distances range from
˚
1.55 to 1.60 A, shorter than in uncomplexed P–N units (1.63–
Fig. 4 Molecular structure of 7 with thermal ellipsoids shown at 50% probability level.
D a l t o n T r a n s . , 2 0 0 5 , 1 9 3 – 1 9 9
1 9 5

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◦
˚
three different ligands. But while acac derivatives show enhanced
stability, hfac (1,1,1,5,5,5-hexafluoro-2,4-pentanedionato) com-
pounds redistribute to form Ga(hfac)3 over days at room tem-
perature. In a similar line, our monomeric Ga(III) compounds
with two or three different ligands are obtained in high yield,
thus evidencing the conferred stabilisation by EPNPEꢀ-type
ligands. The only exception to this behaviour is compound 3,
which undergoes redistribution reactions to render ionic species
9+[GaCl4]− in THF (vide infra).
Table 2 Selected bond lengths (A) and angles ( ) for complexes 2, 4, 5,
7 and 9+
2
Ga(1)–Cl(1)
Ga(1)–Cl(2)
Ga(1)–S(1)
Ga(1)–S(2)
S(1)–P(1)
S(2)–P(2)
P(1)–N(1)
P(2)–N(1)
2.1627(16)
2.1748(16)
2.2692(16)
2.2763(15)
2.0595(19)
2.0466(19)
1.590(5)
Cl(2)–Ga(1)–Cl(1)
Cl(1)–Ga(1)–S(1)
Cl(2)–Ga(1)–S(1)
Cl(1)–Ga(1)–S(2)
Cl(2)–Ga(1)–S(2)
S(1)–Ga(1)–S(2)
P(2)–N(1)–P(1)
109.92(7)
111.39(6)
107.91(6)
113.97(6)
101.62(6)
111.44(5)
132.4(3)
Synthesis and spectroscopy of cationic gallium compound 9+
1.584(5)
During the synthesis of 3 in CH2Cl2 a small new signal in the
1
31P{ H} NMR spectrum in CDCl3 indicated the presence of
4
a second species, later confirmed to be the cationic spirocycle
[Ga(g -{Ph2P(Se)NP(Se)Ph2-Se,Se})2]+ (9+) which balances its
2
Ga(1)–O(3)
Ga(1)–Cl(2)
Ga(1)–Cl(1)
Ga(1)–S(1)
S(1)–P(1)
O(3)–P(2)
P(1)–N(1)
P(2)–N(1)
1.867(3)
O(3)–Ga(1)–Cl(2)
O(3)–Ga(1)–Cl(1)
Cl(2)–Ga(1)–Cl(1)
O(3)–Ga(1)–S(1)
Cl(2)–Ga(1)–S(1)
Cl(1)–Ga(1)–S(1)
P(2)–N(1)–P(1)
107.62(11)
106.99(13)
111.82(7)
106.95(11)
108.39(6)
114.72(6)
137.3(3)
charge with GaCl4−. Thus, pure 3 was dissolved in CDCl3, the
2.1446(14)
2.1494(15)
2.2525(12)
2.0563(15)
1.508(3)
1.567(4)
1.549(4)
NMR tube kept at room temperature and periodically moni-
tored by 31P{ H} NMR spectroscopy. Under these conditions
1
and over a period of several days, a gradual growth of the signal
of 9+ at the expense of 3 was observed [eqn. (3)]. In order to
favour the formation of 9+, the reaction between equimolar
amounts of GaCl3 and K[Ph2P(Se)NP(Se)Ph2] was conducted
in THF. Again, 3 and 9+ were detected, but even from early
monitoring times 9+ was majority (ratio 7 : 3, respectively).
In contrast, only very small amounts of an analogous species,
presumably the corresponding sulfur spirocycle cation, were
5
Ga(1)–Cl(2)
Ga(1)–Cl(1)
Ga(1)–S(2)
Ga(1)–S(1)
S(1)–P(1)
S(2)–P(2)
P(1)–N(1)
P(2)–N(1)
2.1764(6)
2.1767(6)
2.2579(6)
2.2691(6)
2.0592(7)
2.0536(7)
1.5809(16)
1.5789(17)
Cl(2)–Ga(1)–Cl(1)
Cl(2)–Ga(1)–S(2)
Cl(1)–Ga(1)–S(2)
Cl(2)–Ga(1)–S(1)
Cl(1)–Ga(1)–S(1)
S(2)–Ga(1)–S(1)
P(2)–N(1)–P(1)
108.24(3)
107.84(2)
111.61 (3)
104.04(2)
111.83(3)
112.83(2)
135.79(11)
detected in the 31P{ H} NMR spectrum of 2 in CDCl3 or
1
even when the reaction was performed and monitored in
THF. Further, no spectroscopically detectable side products
were observed during the synthesis of 1 in THF. Thus, it appears
the less electronegative the chalcogen bound to gallium, the
more favourable the disproportionation reaction leading to the
formation of the tetrachloride anion becomes.
7
Ga(1)–C(25)
Ga(1)–Cl(1)
Ga(1)–S(1)
Ga(1)–S(2)
S(1)–P(1)
S(2)–P(2)
P(1)–N(1)
P(2)–N(1)
1.948(4)
C(25)–Ga(1)–Cl(1)
C(25)–Ga(1)–S(1)
Cl(1)–Ga(1)–S(1)
C(25)–Ga(1)–S(2)
Cl(1)–Ga(1)–S(2)
S(2)–Ga(1)–S(1)
P(2)–N(1)–P(1)
115.69(12)
113.57(12)
105.73 (5)
110.07(12)
103.31(5)
107.71(4)
127.5(2)
2.1222(15)
2.3576(10)
2.3618(11)
2.0339(13)
2.0266(13)
1.588(3)
1.596(3)
9+
(3)
Ga(1)–Se(1)
Ga(1)–Se(2)
Se(1)–P(1)
Se(2)–P(2)
P(1)–N(1)
P(2)–N(1)
Ga(1)–Se(3)
Ga(1)–Se(4)
Se(3)–P(3)
Se(4)–P(4)
P(4)–N(2)
P(3)–N(2)
2.4047(9)
2.4070(7)
2.1980(14)
2.2078(14)
1.590(4)
Se(2)–Ga(1)–Se(1)
Se(4)–Ga(1)–Se(3)
Se(1)–Ga(1)–Se(3)
Se(1)–Ga(1)–Se(4)
Se(2)–Ga(1)–Se(3)
Se(2)–Ga(1)–Se(4)
P(2)–N(1)–P(1)
105.16(3)
112.77(3)
113.08(3)
108.17(3)
104.56(3)
112.90(3)
131.8(3)
Crystal structure of [9+GaCl4
]
−
9+GaCl4 crystallizes in the triclinic P1 space group with two
crystallographically independent ions 9+ with no statistically
significant differences in either bond lengths or angles.† The
molecular structure of 9+ (Fig. 5) shows the Ga centre in an
approximately tetrahedral arrangement forming part of two
fused metallacycle rings almost perpendicular to each other
(the angle between the planes defined by Se(1)Ga(1)Se(2) and
Se(3)Ga(1)Se(4) is 85.2◦). One of the rings shows a boat
conformation with N(1) and Ga on the apices and the second
ring is a distorted boat with P(4) and Se(3) on the apices.
−
¯
1.599(4)
2.3906(7)
2.4071(8)
2.2196(13)
2.1940(15)
1.598(4)
P(3)–N(2)–P(4)
127.3(3)
1.591(4)
organogallium R3−nGaCpn (R = Me,31,32 Et;32,33 n = 1, 2)
undergo ligand redistribution reactions to form mixtures of
GaR3, R2GaCp, RGaCp2 and GaCp3 when dissolved in donor
solvents. Beachley et al.17 have recently employed bidentate acac-
type ligands to stabilise group 13 heteroleptic compounds with
† The crystal data for 9 is contained in Table 4 and one of the 9+ ions is
shown in Fig. 5 with its relevant bond lengths and angles presented in
Table 2.
Table 3 Selected bond distances and angles of compounds 2 and 7 for comparison with their dimethyl Me2GaL15 analogue
S–Ga–S/◦
X–Ga–Xꢀ/◦
˚
˚
˚
Complex
Ga–S/A
Ga–Cl/A
Ga–CH3/A
[Cl2GaL], 2
[MeClGaL], 7
[Me2GaL]15
2.269(2), 2.276(2)
2.358(1), 2.362(1)
2.416(2), 2.380(1)
2.163(2), 2.175(2)
2.122(2)
111.4(1)
107.7(1)
99.2(1)
109.9(1) (X, Xꢀ = Cl)
1.948(4)
1.978(5), 1.958(5)
115.7(1) (X, Xꢀ = Cl, CH3)
126.1(2) (X, Xꢀ = CH3)
1 9 6
D a l t o n T r a n s . , 2 0 0 5 , 1 9 3 – 1 9 9

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ture of K[(Ph2P(O)NP(O)Ph2] (0.5 g, 1.1 mmol) and GaCl3
(0.19 g, 1.1 mmol) in CH2Cl2 (20 ml) was vigorously stirred for
12 h to afford a KCl precipitate which was separated by cannula
filtration and disregarded. The solution was concentrated under
vacuum and kept at −20 ◦C until crystallisation of 1. Colorless
1 was separated by filtration and dried under reduced pressure.
Yield 84%, mp 171–173 ◦C. IR (KBr, cm−1): 3058 (w), 2964 (w),
1904 (w), 1821 (w), 1692 (w), 1588 (m), 1484 (w), 1437 (m), 1263
(m), 1216 (s), 1126 (s), 1063 (s), 920 (m), 804 (m), 732 (m), 690 (s),
550 (s), 507 (s). 1H NMR (CDCl3, 200 MHz, 293 K) d: 7.3–7.5
1
(m, 12H, m-C6H5 + p-C6H5), 7.7–7.8 (m, 8H, o-C6H5). 13C{ H}
(CDCl3, 50.29 MHz, 293 K) d: 128.6 (m, m-C6H5), 131.0 (m,
1
o-C6H5), 132.3 (s, p-C6H5), 133.5 (d, JPC 109 Hz, ipso-C6H5).
1
31P{ H} (CDCl3, 80.96 MHz, 293 K) d: 33.8 (s). Anal. Calc. for
C24H20Cl2GaNP2O2: C, 51.75; H, 3.62; N, 2.51. Found: C, 51.61;
H, 3.47; N, 2.55%.
Compounds 2 to 5 were prepared in a similar manner to 1.
Synthesis of dichloro(S,Sꢀ-tetraphenyldithioimidodiphosphi-
nato)gallium(III), [Cl2Ga-g2-{Ph2P(S)NP(S)Ph2-S,Sꢀ}] (2).
K[(Ph2P(S)NP(S)Ph2] (0.5 g, 1.0 mmol) and GaCl3 (0.18 g,
1.0 mmol) yielded 2 in 94% after stirring for 14 h. Crystals
suitable for X-ray diffraction were grown from CH2Cl2–hexane
solutions. Mp 166 ◦C. IR (KBr, cm−1): 3063 (w), 2962 (w), 1809
(w), 1580 (w), 1476 (w), 1432 (m), 1210 (s), 1107 (m), 1024 (m),
Fig. 5 Molecular structure of one 9+ ion with thermal ellipsoids shown
at 50% probability level. Hydrogen atoms have been omitted for clarity.
The Ga–Se bond distances in 9+ are significantly shorter (av-
2
ꢀ
1
˚
erage 2.403 A) than in Et2Ga-g -{Ph2P(Se)NP(Se)Ph2-Se,Se }
802 (m), 690 (s), 560 (s), 514 (m), 483 (m). H NMR (CDCl3,
14
˚
(average 2.524 A) as a result of the positive charge on the Ga
200 MHz, 293 K) d: 7.4–7.6 (m, 12H, m-C6H5 + p-C6H5),
1
7.7–7.8 (m, 8H, o-C6H5). 13C{ H} (CDCl3, 50.29 MHz, 293 K)
centre.
Though a number of Ga spirocycles have been structurally
characterised, most of them include N or C in their fused rings.
To date no other Se containing Ga spirocycle has been re-
ported. b-Diketonate stabilized GaClMe(bdk) and GaCl2(bdk)
(bdk = b-diketonate) both react with THF yielding ionic
[Ga(bdk)2(THF)2]+[GaCl4]−.17 In the latter cases, small steric
hindrance allows THF to coordinate to the metal centre.
Presumably, it is the steric bulk which prevents the solvent to
behave similarly in 9+.
d: 128.8 (m, m-C6H5), 131.1 (m, o-C6H5); 132.5 (s, p-C6H5),
1
134.6 (d, 1JPC 106 Hz, ipso-C6H5). 31P{ H} (CDCl3, 80.96 MHz,
293 K) d: 38.2 (s). Anal. Calc. for C24H20Cl2GaNP2S2: C, 48.93;
H, 3.42; N, 2.38. Found: C, 48.89; H, 3.38; N, 2.45%.
Synthesis of dichloro(Se,Seꢀ-tetraphenyldiselenoimidodiphos-
phinato)gallium(III), [Cl2Ga-g2-{Ph2P(Se)NP(Se)Ph2-Se,Seꢀ}]
(3). K[(Ph2P(Se)NP(Se)Ph2] (0.5 g, 0.86 mmol) and GaCl3
(0.15 g, 0.86 mmol) yielded 3 in 85%. Mp 198–200 ◦C. IR
(KBr, cm−1): 3058 (w), 2964 (w), 1579 (w), 1477 (m), 1436 (m),
1260 (s), 1210 (s), 1103 (s), 1025 (s), 803 (s), 747 (m), 688 (s),
531 (s). 1H NMR (CDCl3, 200 MHz, 293 K) d: 7.4–7.6 (m, 12H,
Concluding remarks
1
The synthesis of dichloro and chloromethyl Ga(III) dichalcogen-
imidodiphoshinato complexes proceeds cleanly and in a facile
manner. Their robust ligand skeleton and wide bite angles are
advantages that will be later used to generate cationic gallium
species having as a precedent the isolation of the four-coordinate
Ga spirocycle cation 9+. Further work concerning the isolation
of these cationic species and their mechanisms of formation is
currently in progress.
m-C6H5 + p-C6H5), 7.6–7.8 (m, 8H, o-C6H5). 13C{ H} NMR
(CDCl3, 50.29 MHz, 293 K) d: 129.2 (m, m-C6H5), 131.0 (m,
o-C6H5), 133.2 (s, p-C6H5), 132.6 (dd, 1JPC 104 Hz, 3JPC 4.17 Hz,
1
ipso-C6H5). 31P{ H} (CDCl3, 80.96 MHz, 293 K) d: 33.7 (s, 1JPSe
2
447 Hz, JPP 9.3 Hz). Anal. Calc. for C24H20Cl2GaNP2Se2: C,
42.21; H, 2.95; N, 2.05. Found: C, 41.80; H, 2.83; N, 2.13%.
Synthesis of dichloro(S,Oꢀ-diphenyldiethoxythioimidodiphos-
phinato)gallium(III), [Cl2Ga-g2-{Ph2P(S)NP(O)(OEt)2-S,O}]
(4). K[(Ph2P(S)NP(O)(OEt)2] (0.51 g, 1.25 mmol) and GaCl3
(0.22 g, 1.26 mmol) yielded 4 in 95% after 18 h stirring. Mp
Experimental
◦
63–64 C. IR (KBr, cm−1): 3059 (w), 2967 (m), 2590 (w), 1968
General
(w), 1896 (w), 1818 (m), 1773 (w), 1583 (m), 1479 (s), 1439 (s),
1256 (s, br), 1000 (s, br), 793 (s), 747 (s), 695 (s), 592 (s), 542
All syntheses and manipulations of the air sensitive compounds
were carried out under argon using standard Schlenk or
glove-box techniques. Solvents were dried over sodium or
potassium/benzophenone and freshly distilled prior to use.
The ligands Ph2P(E)NHP(Eꢀ)PPh2 (E, Eꢀ = O,34 S,34 Se35),
1
(s), 460 (m). H NMR (CDCl3, 200 MHz, 293 K) d: 1.3 (dt,
3
4
3
6H, JHH 7.4 Hz, JPH 1 Hz, OCH2CH3), 4.1 (dq, JHH 7 Hz,
3JHP 7.9 Hz, OCH2CH3), 7.4–7.6 (m, 12H, m-C6H5 + p-C6H5),
7.8–7.9 (m, 8H, o-C6H5). 13C{ H} NMR (CDCl3, 100.58 MHz,
1
24
24
293 K) d: 16.1 (d, 3JPC 7.7 Hz, OCH2CH3), 64.6 (d, 2JPC 6.1 Hz,
Ph2P(S)NHP(O)(OEt)2 and Ph2P(S)NHP(S)Me2 were syn-
thesized according to literature methods.
3
2
OCH2CH3), 129.0 (d, JPC 14.5 Hz, m-C6H5), 131.1 (d, JPC
4
NMR spectra were obtained on Varian-Inova-400 MHz
and Varian-Gemini-200 MHz instruments. Chemical shifts are
11.8 Hz, o-C6H5), 132.9 (d, JPC 3.0 Hz, p-C6H5), ipso-C6H5
not observed. 31P{ H} (CDCl3, 161.92 MHz, 293 K) d: 2.9 (d,
1
1
reported relative to SiMe4 for H and 13C, 85% H3PO4 for 31P
2JPP 24.4 Hz, PO), 35.0 (d, JPP 24.4 Hz, PS) Anal. Calc. for
2
and are in ppm. IR Spectra were recorded as KBr pellets on
a Brucker Equinox 55 Spectrometer and are reported in cm−1.
Microanalyses were obtained on an Elementar Vario EL III
instrument operating in the CHN mode.
C16H20Cl2GaNP2O3S: C, 36.76; H, 3.96; N, 2.75. Found: C,
37.58; H, 3.81; N, 2.91%.
Synthesis of dichloro(S,Sꢀ-dimethyldiphenyldithioimidodiphos-
phinato)gallium(III), [Cl2Ga-g2-{Ph2P(S)NP(S)Me2-S,Sꢀ}] (5).
K[(Ph2P(S)NP(S)Me2] (0.31 g, 0.85 mmol) and GaCl3 (0.15 g,
0.86 mmol) yielded 5 in 92% after 18 h stirring. Mp 138–140 ◦C.
1H NMR (CDCl3, 400 MHz, 293 K) d: 1.9 (d, 6H, 2JPH 13.6 Hz,
PMe2), 7.5–7.6 (m, 12H, m-C6H5 + p-C6H5), 7.7–7.8 (m, 8H,
Preparation of dihalogenated species
Synthesis of dichloro(O,Oꢀ-tetraphenylimidodiphosphinato)
gallium(III), [Cl2Ga-g2-{Ph2P(O)NP(O)Ph2-O,Oꢀ}] (1). A mix-
D a l t o n T r a n s . , 2 0 0 5 , 1 9 3 – 1 9 9
1 9 7

View Article Online
Table 4 Summary of crystallographic data for complexes 2, 4, 5, 7 and 9 (refinement method: full-matrix least-squares on F2).
2
4
5
7
9
Formula
Mr
C24H20Cl2GaNP2S2
589.13
100(2)
0.71073
Monoclinic
C16 H20Cl2GaNO3P2 S C14H16Cl2GaNP2S2
C25H23ClGaNP2S2
568.71
100(2)
0.71073
Orthorhombic
Pbca
15.2636(18)
17.995(2)
18.335(2)
90.0
90.0
90.0
5036.0(10)
8
1.500
C48H40Cl4Ga2N2P4Se4
1365.84
508.97
293(2)
464.99
100(2)
T/K
150(2)
0.71073 A
˚
˚
k/A
0.71073
Triclinic
P1
0.71073
Triclinic
P1
Crystal system
Triclinic
¯
P1
¯
¯
Space group
P21/n
˚
a/A
10.7275(12)
16.0085(17)
15.2662(17)
90.0
98.097(2)
90.0
2595.5(5)
4
1.508
9.3056(10)
9.6427(10)
14.6899(15)
76.044(2)
73.046(2)
62.095(2)
1105.7(2)
2
9.4244(7)
9.9156(7)
11.1223(8)
86.4200(10)
85.5120(10)
73.4930(10)
992.59(12)
2
14.544(2)
15.672(2)
24.498(3)
89.897(3)
89.963(3)
70.891(3)
5276.5(13)
8
˚
b/A
˚
c/A
a/◦
b/◦
c /◦
3
˚
V/A
Z
Dc/g cm−3
1.529
1.556
1.719
4.140
l/mm−1
1.564
1.740
2.021
1.507
F(000)
1192
516
468
2320
2672
Crystal size/mm
h range for data
collection/◦
Index ranges, hkl
0.18 × 0.23 × 0.27
0.22 × 0.33 × 0.37
0.15 × 0.22 × 0.37
0.14 × 0.18 × 0.27
0.17 × 0.24 × 0.26
1.85–25.02
1.46–27.04
1.84–27.02
2.07–27.05
1.38–27.07
−12 to 12, −19 to
10, −16 to 18
12984
−11 to 11, −12 to 12,
−18 to 18
−11 to 12, −12 to 12,
−14 to 14
−19 to 19, −19 to
21, −6 to 23
21966
−10 to 18, −19 to 19,
−31 to 27
No. refl. collected
12474
9674
22640
No. indep. refl. (Rint
)
4566 (0.0297)
4785 (0.0292)
4785/4/228
0.878
4263 (0.0209)
4263/0/201
1.074
5319 (0.0271)
5319/0/290
1.107
19831 (0.0211)
19831/0/1153
1.067
Data/restraints/params. 4566/0/247
Goodness-of-fit on F2
Final R indices [I >
2r(I)]
1.028
R1 = 0.0657,
wR2 = 0.1539
2.918, −2.647
R1 = 0.0522, wR2 =
R1 = 0.0282, wR2 =
R1 = 0.0514, wR2 =
R1 = 0.0484, wR2 =
0.1710
0.0769
0.1427
0.1250
Largest diff. peak,
1.456, −1.177
0.372, −0.300
0.823, −1.850
2.005, −1.203
−3
˚
hole/e A
1
o-C6H5). 13C{ H} NMR (CDCl3, 100.58 MHz, 293 K) d: 25.3 (d,
1JPC 72.5 Hz, PMe2), 129.1 (d, 3JPC 14.5 Hz, m-C6H5), 131.2 (d,
2JPC 12.17 Hz, o-C6H5), 132.9 (d, 4JPC 3.12 Hz, p-C6H5), 134.2 (d,
1814 (w), 1581 (m), 1477 (m), 1433 (s), 1391 (w), 1339 (w), 1308
(w), 1260 (m), 1201 (s), 1105 (s), 1024 (m), 997 (m), 923 (w),
851 (w), 808 (m), 745 (s), 695 (s), 608 (m), 568 (s), 520 (m), 490
1
1JPC 107 Hz, ipso-C6H5). 31P{ H} (CDCl3, 161.92 MHz, 293 K)
1
(m), 467 (m). H NMR (CDCl3, 200 MHz, 293 K) d: 0.0 (s,
2
3H, GaMe), 7.3–7.5 (m, 12H, m-C6H5 + p-C6H5), 7.8 (m, 8H,
d: 44.0( (br, w1/2 28.2 Hz, PMe2), 36.5 (d, JPP 14.1 Hz, PPh2).
1
o-C6H5). 13C{ H} NMR (CDCl3, 50.29 MHz, 293 K) d: 1.5 (s,
Anal. Calc. for C14H16Cl2GaNP2S2: C, 36.16; H, 3.47; N, 3.01.
Found: C, 36.02; H, 3.21; N, 3.15%.
GaMe), 128.2 (m, m-C6H5), 131.1–132.0 (m, o- C6H5 + p-C6H5),
1
1
134.7 (d, JPC 103 Hz, ipso-C6H5). 31P{ H} NMR (CDCl3,
80.96 MHz) d: 37.8 (s). Anal. Calc. for C24H20Cl2GaNP2O2: C,
51.75; H, 3.62; N, 2.51. Found: C, 51.61; H, 3.47; N, 2.55%.
Preparation of chloromethylated species
Synthesis of chloromethyl(O,Oꢀ-tetraphenylimidodiphosphi-
nato)gallium(III), [ClMeGa-g2-{Ph2P(O)NP(O)Ph2-O,Oꢀ}] (6).
GaMe2Cl was generated in situ by stirring GaCl3 (0.05 g,
0.29 mmol) and GaMe3 (0.07 g (0.61 mmol) in 10 ml toluene
for 1 h. To this solution (OPPh2)2NH (0.38 g, 0.91 mmol) in
10 ml toluene was added dropwise. The stirring was continued
for a further 6 h after which the solution was concentrated
under vacuum and kept at −20 ◦C until a white precipitate
was obtained. Yield 93%, mp 177–178 ◦C. IR (KBr, cm−1): 3058
(m), 2978 (w), 2917 (w), 2615 (w), 2323 (w), 2251 (w), 2060 (w),
1965 (w), 1899 (w), 1820 (w), 1775 (w), 1677 (w), 1591 (w), 1484
(m), 1437 (m), 1262 (br s), 1185 (s), 1126 (s), 1135 (s), 1094 (s),
Synthesis of chloromethyl(Se,Seꢀ-tetraphenyldiselenoimid-
odiphosphinato)gallium(III), [ClMeGa-g2-{Ph2P(Se)NP(Se)Ph2-
Se,Seꢀ}] (8). Compound 8 was obtained from GaCl3 (0.04 g
(0.23 mmol), GaMe3 (0.05 g, 0.44 mmol) and (SePPh2)2NH
(0.36 g, 0.66 mmol). Yield 91%, mp 206–207 ◦C. IR (KBr, cm−1):
3053 (w), 2969 (w), 2365 (w), 1991 (w), 1894 (w), 1813 (w), 1581
(w), 1474 (m), 1433 (s), 1331 (w), 1305 (w), 1200 (s), 1103 (s),
1023 (m), 994 (m), 846 (w), 797 (m), 744 (s), 722 (m), 690 (s), 577
(m), 537 (s), 507 (s), 467 (m). 1H NMR (CDCl3, 200 MHz, 293 K)
d: 0.1 (s, 3H, GaMe), 7.3–7.5 (m, 12H, m-C6H5 + p-C6H5), 7.8
1
(m, 8H, o-C6H5). 13C{ H} NMR (CDCl3, 50.29 MHz, 293 K)
1
1044 (s), 978 (s), 804 (s), 732 (s), 680 (s), 549 (s), 508 (s). H
d: 3.9 (s, GaMe), 128.5 (m, m-C6H5), 131.1 (m, o-C6H5), 132.0
(br s, p-C6H5), 134.7 (dd, 1JPC 101 Hz, 3JPC 6.5 Hz, ipso-C6H5).
NMR (CDCl3, 200 MHz, 293 K) d: 0.1 (s, 3H, GaMe), 7.3–
7.5 (m, 12H, m-C6H5 + p-C6H5), 7.8 (m, 8H, o-C6H5). 13C{ H}
31P{ H} NMR (CDCl3, 80.96 MHz) d: 31.7 (s, 1JPSe 485 Hz, 2JPP
1
1
NMR (CDCl3, 100.58 MHz, 293 K) d: −5.3 (s, GaMe), 128.4
(m, m-C6H5), 131.0 (m, o-C6H5), 131.8 (m, p-C6H5), 135.3 (d,
5.9 Hz). Anal. Calc. for C25H23ClGaNP2Se2: C, 45.32; H, 3.50;
N, 2.11. Found: C, 45.18; H, 3.39; N, 2.18%.
1
1JPC 107 Hz, ipso-C6H5). 31P{ H} (CDCl3, 161.92 MHz, 293 K)
d: 29.9 (s). Anal. Calc. for C25H23ClGaNP2O2: C, 55.96; H, 4.32;
N, 2.61. Found: C, 56.31; H, 4.44; N, 2.74%.
Synthesis of tetrachlorogallatobis(Se,Seꢀ-tetraphenyldi-
selenoimidodiphosphinato)gallium(III), [Ga-{g2-(Ph2P(Se)
NP(Se)Ph2-Se,Seꢀ)}2][GaCl4] (9)
Compounds 7 and 8 were obtained in a similar fashion to 6.
Synthesis of chloromethyl(S,Sꢀ-tetraphenyldithioimidodiphos-
K[Ph2P(Se)NP(Se)Ph2] (0.50 g, 0.86 mmol) and GaCl3 (0.15 g,
0.86 mmol) were stirred in THF (20 ml). The solution was
removed by cannula and formed KCl disregarded. The solution
was then concentrated under vacuum and left for to crystallise
slowly at −20 ◦C over a period of weeks. Yield 83%. Crystals of 9
were also obtained from slow crystallisation of 3 in CH2Cl2 after
phinato)gallium(III),
(7). Compound
[ClMeGa-g2-{Ph2P(S)NP(S)Ph2-S,Sꢀ}]
7
was obtained from GaCl3 (0.05 g,
0.29 mmol), GaMe3 (0.07 g, 0.61 mmol) and (SPPh2)2NH
(0.4 g, 0.89 mmol). Crystals suitable for X-ray diffractio◦n were
grown from toluene solutions. Yield 92%, mp 177–178 C. IR
(KBr, cm−1): 3054 (m). 2968 (w), 2365 (w), 1966 (w), 1900 (w),
1
several weeks. H NMR (CDCl3, 200 MHz, 293 K) d: 7.4–7.6
1 9 8
D a l t o n T r a n s . , 2 0 0 5 , 1 9 3 – 1 9 9

View Article Online
1
(m, 12H, m-C6H5 + p-C6H5), 7.7–7.8 (m, 8H, o-C6H5). 31P{ H}
6 S. Dagorne, I. A. Guzei, M. P. Coles and R. F. Jordan, J. Am. Chem.
Soc., 2000, 122, 274.
7 J. Klosin, G. R. Roof, E. Y. X. Chen and K. A. Abboud,
Organometallics, 2000, 19, 4684.
8 A. V. Korolev, F. Delpech, S. Dagorne, I. A. Guzei and R. F. Jordan,
Organometallics, 2001, 20, 3367.
9 D. A. Atwood, J. A. Jegier and D. Rutherford, J. Am. Chem. Soc.,
1995, 117, 6997.
10 M. Bruce, V. C. Gibson, C. Redshaw, G. A. Solan, A. J. P. White and
D. J. Williams, Chem. Commun., 1998, 2523.
11 D. A. Atwood, Main Group Chem. News, 1998, 5, 30.
12 R. J. Wehmschulte, J. M. Steele and M. A. Khan, Organometallics,
2003, 22, 4678.
13 K. C. Kim, C. A. Reed, G. S. Long and A. Sen, J. Am. Chem. Soc.,
2002, 124, 7662.
14 M. A. Mun˜oz-Herna´ndez, A. Singer, D. A. Atwood and R. Cea-
Olivares, J. Organomet. Chem., 1998, 571, 15.
15 V. Montiel-Palma, E. Huitro´n-Rattinger, S. Corte´s-Llamas, M. A.
Mun˜oz-Herna´ndez, E. Lo´pez-Honorato, V. Garc´ıa-Montalvo and
C. Silvestru, Eur. J. Inorg. Chem., 2004, 3743.
16 A. V. Korolev, E. Ihara, I. A. Guzei, V. G. Young, Jr. and R. F. Jordan,
J. Am. Chem. Soc., 2001, 123, 8291.
17 O. T. Beachley, J. R. Gardinier and M. R. Churchill, Organometallics,
2003, 22, 1145.
18 O. T. Beachley, J. R. Gardinier, M. R. Churchill, D. G. Churchill and
K. M. Keil, Organometallics, 2002, 21, 946.
19 J.-H. Park, M. Afzaal, M. Helliwell, M. A. Malik, P. O’Brien and J.
Raftery, Chem. Mater., 2003, 15, 4205.
20 C. Silvestru and J. E. Drake, Coord. Chem. Rev., 2001, 223, 117.
21 D. J. Williams, Inorg. Nucl. Chem. Lett., 1980, 16, 189.
22 A. M. Z. Slawin, J. Ward, D. J. Williams and J. D. Woollins, Chem.
Commun., 1994, 421.
23 P. Bahttacharyya, A. M. Z. Slawin, D. J. Williams and J. D. Woollins,
J. Chem. Soc., Dalton Trans., 1995, 2489.
24 G. Balazs, J. E. Drake, C. Silvestru and I. Haiduc, Inorg. Chim. Acta,
1999, 287, 61.
1
NMR (CDCl3, 80.96 MHz, 293 K) d: 32.6 (s, JPSe 453 Hz).
Anal. Calc. for C48H40Cl4Ga2N2P4Se4: C, 42.21; H, 2.95; N, 2.05.
Found: C, 42.12; H, 3.11; N, 2.17%.
X-Ray crystallographic studies
Single-crystal X-ray diffraction data for 2, 4, 5, 7 and 9 were
collected using the program SMART36 on a Brucker APEX
CCD diffractometer with monochromatized Mo-Ka radiation
(k = 0.71073 A). Cell refinement and data reduction were
˚
carried out with the use of the program SAINT, the program
SADABS was employed to make incident beam, decay and
absorption corrections in the SAINT-Plus v. 6.0 suite.37 Then,
the structures were solved by direct methods with the program
SHELXS and refined by full-matrix least-squares techniques
with SHELXL in the SHELXTL v. 6.1 suite.38 Hydrogen atoms
were generated in calculated positions and constrained with the
use of a riding model. The final models involved anisotropic
displacement parameters for all non-hydrogen atoms. Except
in the following cases, such refinements were straightforward.
Further details of the structure analyses are given in Table 4.
In compound 2 two carbon atoms of a phenyl ring (C19–
C24) are disordered. They were constrained to fit a regular
hexagon with the rest of the carbon atoms of the ring with C–C
˚
bond distances at 1.39 A and constrained to the same isotropic
thermal parameters. In compound 4 the two OEt moieties each
attached to one phosphorus atom were refined restraining the
O1–C13 and O2–C15 bond distances to 1.54 A, and the C13–
˚
˚
C14 and C15–C16 bond distances to 1.43 A. The anisotropic
thermal parameters of O1, C13 and C14 were fixed to the
same value. Despite the high number of refinement cycles (up to
20) the maximum/shift error was not reduced to a satisfactory
value and remained at 10.13, this may be a consequence of the
poor quality of the crystal. Compound 9 was attempted to be
solved in the monoclinic space group P21/n but did not give a
25 R. Ro¨sler, J. E. Drake, C. Silvestru, J. Yang, I. Haiduc and G.
Espinoza-Pe´rez, J. Chem. Soc., Dalton Trans., 1998, 73.
26 R. Ro¨sler, C. Silvestru, G. Espinoza-Pe´rez, I. Haiduc and R. Cea-
Olivares, Inorg. Chim. Acta, 1996, 241, 47.
27 J. E. Drake, M. B. Hursthouse, M. Kulcsar, M. E. Light and C.
Silvestru, J. Organomet. Chem., 2001, 623, 153.
28 M. M. Akobiya, V. I. Bregadze, L. M. Golubinskaya, S. Gundersen,
A. Haaland, H. V. Volden, V. S. Mastryukov and I. F. Shishkov,
J. Organomet. Chem., 1994, 467, 161.
29 R. J. Wehmschulte, J. M. Steele and M. A. Khan, Organometallics,
2003, 22, 4678.
¯
satisfactory solution. However, in the triclinic space group P1 a
straightforward solution was obtained.
CCDC reference numbers 248107–248111.
See http://www.rsc.org/suppdata/dt/b4/b412874e/ for cry-
stallographic data in CIF or other electronic format.
30 M. P. Coles, D. C. Swenson and R. F. Jordan, Organometallics, 1997,
16, 5183.
31 O. T. Beachley, T. L. Royster and J. R. Arhar, J. Organomet. Chem.,
1992, 434, 11.
32 O. T. Beachley and M. T. Mosscrop, Organometallics, 2000, 19, 4550.
33 O. T. Beachley, D. B. Rosenblum, M. R. Churchill, C. H. Lake and
L. M. Krajkowski, Organometallics, 1995, 14, 4402.
34 F. T. Wang, J. Najdzionek, K. L. Leneker, H. Wasserman and D. M.
Braitsch, Synth. React. Inorg. Met.-Org. Chem., 1978, 8, 119–125.
35 P. Bahttacharyya, J. Novasad, J. Phillips, A. M. Z. Slawin, D. J.
Williams and J. D. Woollins, J. Chem. Soc., Dalton Trans., 1995,
1607.
Acknowledgements
UC-MEXUS and CONACYT (Project J30234-E) are thanked
for generous financial support and postgraduate (S. C. L. and
N. T. F.) and undergraduate (E. H. R.) studentships.
References
1 D. A. Atwood, Coord. Chem. Rev., 1998, 176, 407.
2 M. Bochmann and D. M. Dawson, Angew. Chem., Int. Ed. Engl.,
1996, 35, 2226.
3 M. P. Coles and R. F. Jordan, J. Am. Chem. Soc., 1997, 119, 8125.
4 F. Delpech, I. A. Guzei and R. F. Jordan, Organometallics, 2002, 21,
1167.
36 G. M. Sheldrick, SMART Bruker AXS, Inc., Madison, WI, USA,
2000.
37 G. M. Sheldrick, SAINT-Plus 6.0 Bruker AXS, Inc., Madison, WI,
USA, 2000.
5 M. A. Mun˜oz-Herna´ndez, B. Sannigrahi and D. A. Atwood, J. Am.
Chem. Soc., 1999, 121, 6747.
38 G. M. Sheldrick, SHELXTL 6.10 Bruker AXS, Inc., Madison, WI,
USA, 2000.
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