Reactions of the clusters [Os3(CO)10(MeCN)2)] and [Ru3(CO)12] with (2-aminophenyl)phosphine P(2-NH2C6H4)H2.: A comparison of the reactivity of amino and phosphino groups with clusters

Article abstract of DOI:10.1016/S0020-1693(02)01259-8

The reaction of (2-aminophenyl)phosphine P(2-NH₂C₆H₄)H₂ with [Os₃(CO)₁₀(MeCN)₂] gives the compounds [Os₃(CO)₁₁{P(2-NH₂C₆H ₄)H₂}] (1), [1,2-Os₃(CO)₁₀{P(2-NH₂C₆H ₄)H₂}₂] (2) and [Os₃(μ-H)(CO)₁₀{μ-P(2-NH₂C ₆H₄)H}] (3). Thermolysis of compounds 1 and 3 in cyclohexane affords in quantitative yields [Os₃(μ-H)₂(CO)₉{μ₃-P (2-NH₂C₆H₄)}] (4). However, the direct reaction of P(2-NH₂C₆H₄)H₂ with [Ru₃(CO)₁₂] yields only the nonacarbonyl species [Ru₃(μ-H)₂(CO)₉{μ₃-P (2-NH₂C₆H₄)}] (5). The phosphino group coordinates more favorably than the amino group and P-H bond activation is favored over amino coordination.

Full text of DOI:10.1016/S0020-1693(02)01259-8

Inorganica Chimica Acta 344 (2003) 123Á127
/
www.elsevier.com/locate/ica
Reactions of the clusters [Os3(CO)10(MeCN)2)] and [Ru3(CO)12] with
(2-aminophenyl)phosphine P(2-NH2C6H4)H2.
A comparison of the reactivity of amino and phosphino groups with
clusters
Alejandro J. Arce a, Rube´n Machado a,*, Ysaura De Sanctis a, Teresa Gonza´lez a,
Reinaldo Atencio a, Antony J. Deeming b
a Chemistry Center, Instituto Venezolano de Investigaciones Cient´ıficas (IVIC), Apartado 21827, Caracas 1020-A, Venezuela
b Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
Received 24 May 2002; accepted 2 August 2002
Abstract
The reaction of (2-aminophenyl)phosphine P(2-NH2C6H4)H2 with [Os3(CO)10(MeCN)2] gives the compounds [Os3(CO)11{P(2-
NH2C6H4)H2}] (1), [1,2-Os3(CO)10{P(2-NH2C6H4)H2}2] (2) and [Os3(m-H)(CO)10{m-P(2-NH2C6H4)H}] (3). Thermolysis of
compounds 1 and 3 in cyclohexane affords in quantitative yields [Os3(m-H)2(CO)9{m3-P(2-NH2C6H4)}] (4). However, the direct
reaction of P(2-NH2C6H4)H2 with [Ru3(CO)12] yields only the nonacarbonyl species [Ru3(m-H)2(CO)9{m3-P(2-NH2C6H4)}] (5). The
phosphino group coordinates more favorably than the amino group and PÃ
/
H bond activation is favored over amino coordination.
# 2002 Elsevier Science B.V. All rights reserved.
Keywords: Osmium; Ruthenium; Oxidative addition; 2-Aminophenylphosphine; Carbonyl clusters
1. Introduction
tion of four triosmium clusters derived from the reaction
of (2-aminophenyl)phosphine P(2-NH2C6H4)H2 and
[Os3(CO)10(MeCN)2]. Also we report here the direct
reaction with [Ru3(CO)12] to give exclusively the cluster
[Ru3(m-H)2(CO)9{m3-P(2-NH2C6H4)}]. Reactions occur
exclusively at the PH2 rather than at the NH2 group,
which remained non-coordinated in all the new clusters
obtained.
The chemistry of phenylphosphine-containing ligands
with mixed functionality has received less attention than
that of their unsubstituted phosphine counterparts.
There are some studies of complexes of transition metals
with ligands such as (2-hydroxophenyl)diphenylpho-
sphine [1] and (2-aminophenyl)diphenylphosphine [2Á
4]. The reactions of (2-aminophenyl)diphenylphosphine
P(2-NH2C6H4)R2 (RꢀC6H5) with [Os3(CO)12ꢁx
(MeCN)x] (xꢀ1, 2) have been reported to give the
clusters [Os3(CO)11{P(2-NH2C6H4)R2}] and
/
/
-
/
2. Experimental
[HOs3(CO)9{P(2-NHC6H4)R2}] where the latter shows
the ligand bridging one edge of the Os3 triangle by the
amido nitrogen shared between two Os atoms, and the
phosphorus atom coordinated to one of these metals [5].
In this paper we describe the synthesis and characteriza-
2.1. Synthesis of compounds 1Á5
/
All the reactions were performed under nitrogen
atmosphere. Solvents were purified by standard meth-
ods and distilled prior to use. [Os3(CO)10(MeCN)2] [6]
and (2-aminophenyl)phosphine [7] were prepared by
published procedures. [Ru3(CO)12] was purchased from
Strem Chem. IR spectra were recorded in cyclohexane
and 1H and 31P NMR spectra were obtained at 300
* Corresponding author. Tel.: ꢂ
5041350.
E-mail address: rmachado@ivic.ve (R. Machado).
/58-212-5041637; fax: ꢂ58-212-
/
0020-1693/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 0 - 1 6 9 3 ( 0 2 ) 0 1 2 5 9 - 8

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A.J. Arce et al. / Inorganica Chimica Acta 344 (2003) 123Á127
/
MHz. Synthesis of 1, 2 and 3: [Os3(CO)10(MeCN)2] (0.1
g, 0.11 mmol) was added to a refluxing solution of (2-
aminophenyl)phosphine (0.027 g, 0.22 mmol) in 50 ml of
THF. The solution was refluxed for 45 min (IR
monitoring), during which time the color changed
from pale yellow to orange. Low-pressure removal of
NH2C6H4)H2}2] (2) (0.010 g, 9%) both as yellow solids,
and [Os3(m-H)(CO)10{m-P(2-NH2C6H4)H}] (3) as yellow
crystals from n-C6H14ÁCH2Cl2 (0.022 g, 20%). Thermal
/
treatment of compound 3: [Os3(m-H)(CO)10{m-P(2-
NH2C6H4)H}] (3) (0.015 g) were dissolved in 30 ml of
cyclohexane and heated under reflux for 48 h (IR
monitoring). TLC as above gave a high yield of
[Os3(m-H)2(CO)9{m3-P(2-NH2C6H4)}] (4) (0.012 g,
80%). Synthesis of 5: (2-Aminophenyl)phosphine (0.04
the volatiles and TLC of the residue (SiO2, n-C6H14Á
/
CH2Cl2 7/3, v/v), yielded [Os3(CO)11{P(2-
NH2C6H4)H2}] (1), (0.010 g, 9%) and [Os3(CO)10{P(2-
Table 1
IR and NMR data for the new complexes
a
b
b
Compound
n(CO) (cmꢁ1
)
1H NMR (d,
J (Hz)
31P{1H} NMR (d,
ppm)
ppm)
[Os3(CO)11{P(2-NH2C6H4)H2}] (1)
2109w, 2056s, 2036s, 2020vs, 1988ms
7.35 (ddd, H4)
7.30 (m, H2)
6.90 (m, H3)
6.80 (m, H1)
6.20 (d, PH2)
3.97 (brs, NH2)
H2H3ꢀ
H2H4ꢀ
H3H4ꢀ
H3Pꢀ
H4Pꢀ
H2Pꢀ
/
7.5
1.4
7.6
ꢁ
/
130.5
129.5
70.9
/
/
/
7.6
/
17
/
376
[Os3(CO)10{P(2-NH2C6H4)H2}2] (2) 2090w, 2033s, 2004vs, 1968s
7.35 (ddd, H4)
7.32 (m, H2)
6.90 (m, H3)
6.75 (m, H1)
6.20 (d, PH2)
3.97 (brs, NH2)
H2H3ꢀ
H2H4ꢀ
H3H4ꢀ
/
7.5
1.5
7.6
ꢁ/
/
/
H3Pꢀ
H4Pꢀ
H2Pꢀ
/
7.6
/15
/372
[Os3(m-H)(CO)10{m-P(2-
NH2C6H4)H}] (3)
2105m, 2062vs, 2055sh, 2021s,2008s, 1994s
7.24 (dd, H3)
H1H2ꢀ
/
7.5
ꢁ/
7.20 (dd, PH)
7.12 (ddd, H4)
6.83 (ddbr, H2)
6.65 (dd, H1)
H2H3ꢀ
/
7.6
1.3
7.8
H2H4ꢀ
H3H4ꢀ
/
/
H1Pꢀ
/
7.9
4.12 (brs, NH2)
-19.4 (dd, OsH)
H4Pꢀ
/
17
(OsH)Pꢀ
17.9
(OsH)PHꢀ
HPꢀ407
/
/
4
/
d
[Os3(m-H)2(CO)9{m3-P(2-
NH2C6H4)}] (4)
2105m, 2076vs, 2049vs, 2032vs, 2012vs, 1988s, 7.79 (dddd, H4)
H1H2ꢀ
/
8.3
88.8
c
1974s
7.38 (m, H2)
H1H3ꢀ
/
1.2
0.5
7.2
1.6
7.8
6.95 (dddd, H1)
6.79 (m, H3)
4.52 (brs, NH2)
H1H4ꢀ
H2H3ꢀ
H2H4ꢀ
H3H4ꢀ
/
/
/
ꢁ
/
22.1 (d, OsH)
/
H1Pꢀ
H2Pꢀ
H3Pꢀ
H4Pꢀ
/
6.8
1.9
2.3
17.9
/
/
/
(OsH2)Pꢀ
/12
[Ru3(m-H)2(CO)9{m3-P(2-
NH2C6H4)}] (5)
2105m, 2075s, 2048vs, 2033m, 2019vs, 1997s, 7.76 (ddd, H4)
H1H2ꢀ
/
7.5
245
c
1984s
7.36 (m, H1)
6.83 (m, H2, H3)
H1H3ꢀ
H2H4ꢀ
H3H4ꢀ
/
1.5
1.5
7.9
/
3.73 (brs, NH2)
/
ꢁ
/
19.2 (d, RuH)
H1Pꢀ
H4Pꢀ
/
7.5
/16.1
(RuH2)Pꢀ15
/
a
In CH2Cl2.
In CDCl3, 300 MHz, 296 K.
b
c
In C6H12
In CD3COCD3.
.
d

A.J. Arce et al. / Inorganica Chimica Acta 344 (2003) 123Á
/127
125
g, 0.32 mmol) was added to a refluxing solution of
[Ru3(CO)12] (0.2 g, 0.32 mmol) in 50 ml of C6H5CH3.
The solution was refluxed for 30 min (IR monitoring).
TLC separation (SiO2, n-C6H14Á
[Ru3(m-H)2(CO)9{m3-P(2-NH2C6H4)] (5) as orange crys-
tals from n-C6H14ÁCH2Cl2 (0.043 g, 20%).
/CH2Cl2 4/1, v/v), gave
/
2.2. X-ray analysis for 3 and 5
Selected crystals were mounted on fiberglass and
placed on a Rigaku AFC7S diffractometer using gra-
phite monochromated Mo Ka radiation. Data were
collected at room temperature using the v Á2u scan
/
technique to a maximum 2u value of 508. In both cases
the cell was refined using 25 carefully centered reflec-
tions by full-matrix least-squares techniques. Instrument
and crystals stabilities were checked by measuring three
standard reflections periodically. Data were corrected
for Lp effects and for absorption based on empirical
(DIFABS) for 3 and c-scans methods for 5. The
structures were solved by direct methods (SHELXTL
-
PLUS v. NT 5.1) and refined by full-matrix least-squares.
For both complexes, crystal parameters, data collection
and structure refinements are given in Table 4. All non-
hydrogen atoms were refined anisotropically, and hy-
drogen atoms were added at calculated positions, except
for the H atom on the phosphorous in 3 which was
located and refined by using a riding model. Positions of
the hydride atoms were observed in the last residual
density map and were included without any further
refinement. Full-matrix least-squares refinement was
based on F2.
Scheme 1.
trum in the carbonyl region shows only four n(CO)
absorption bands, very similar to those of other
disubstituted clusters with tertiary phosphines [8]. Based
upon spectroscopic evidence, the structure depicted by 2
in Scheme 1 is the most likely. The single broad 31P{1H}
NMR signal at room temperature (d ꢁ
three different signals at 213 K, two of equal intensity
(ꢁ129.5 and ꢁ134.7 ppm) and a lower intensity signal
at ꢁ131 ppm, suggesting the presence of two isomers in
/
129.5 ppm) gives
/
/
/
solution rapidly exchanging at room temperature, as
found for [Os3(CO)10(PMe2Ph)2] [10].
3. Results and discussion
The labile cluster [Os3(CO)10(MeCN)2] reacts readily
with 2 equiv. of the substituted phenyl phosphine P(2-
NH2C6H4)H2 to yield three products including the
monophosphine cluster [Os3(CO)11{P(2-NH2C6H4)H2}]
(1) which possibly derived from [Os3(CO)11(MeCN)]
impurity in [Os3(CO)10(MeCN)2]. Compound 1 is air
stable and has been characterized spectroscopically. The
IR spectrum contains only four n(CO) bands between
2100 and 1900 cmꢁ1 (Table 1), a very similar IR
spectrum to those of tertiary phosphine clusters of the
type [Os3(CO)11(PR3)] [8]. Phosphine rather than amine
coordination is supported by the low-field shift of the
31P{1H} NMR signal in 1 (d ꢁ
free ligand (d ꢂ151.4) as found in the coordinated
phosphines [Os3(CO)11(PR)H2] (RꢀPh, C6H11,
/
130.5) from that of the
/
/
C6H4OCH3) [9]. The ligand acts as a two electron-donor
at just one coordination site in the triosmium frame as
observed for monodentate phosphines. Two more
derivatives are obtained, one is the disubstituted cluster
[1,2-Os3(CO)10{P(2-NH2C6H4)H2}2] (2); the IR spec-
Fig. 1. An ORTEP drawing of the molecular structure of [Os3(m-
H)(CO)10{m-P(2-NH2C6H4)H}] (3).

126
A.J. Arce et al. / Inorganica Chimica Acta 344 (2003) 123Á127
/
Table 2
˚
Selected bond lengths (A) and angles (8) for compound 3
Bond lengths Bond angles
Os(1)Ã
Os(1)Ã
Os(2)Ã
Os(2)Ã
Os(3)Ã
C(1)Ã
/
Os(2)
Os(3)
Os(3)
(P1)
2.891(2)
2.894(1)
2.911(1)
2.366(5)
2.380(6)
1.80(2)
Os(1)Ã
Os(1)Ã
Os(2)Ã
Os(3)Ã
Os(2)Ã
/
Os(2)Ã
/
P(1)
P(1)
84.5(1)
84.2(1)
/
/
Os(3)Ã
/
/
/
P(1)Ã
P(1)Ã
P(1)Ã
/
C(1)
C(1)
Os(3)
122.5(8)
121.0(7)
75.7(2)
/
/
/
/P(1)
/
/
/
P(1)
Also from this reaction, the oxidative addition
compound [Os3(m-H)(CO)10{m-P(2-NH2C6H4)H}] (3)
was obtained; its 31P{1H} NMR spectrum shows a low
field signal at dꢀ
bridging an OsÃOs bond. The hydride signal in the H
NMR spectrum at dꢀ 19.4 ppm, with J(OsÃH)Pꢀ
17.9 and J(OsÃH)PHꢀ4 Hz, confirms the presence of
/
ꢁ
/
70.9 ppm typical for a P atom
1
/
/
ꢁ
/
/
/
Fig. 2. An ORTEP drawing of the molecular structure of [Ru3(m-
H)2(CO)9{m3-P(2-NH2C6H4)}] (5).
/
/
the bridging hydride in the same edge of the osmium
triangle bridged by the phosphido group. In the forma-
tion of 3, deprotonation of the phosphine occurs by
hydrogen atom transfer to the metal centers; no activa-
tion of the NH2 group has been observed based on the
1H NMR spectrum (Table 1). This arrangement has
been confirmed by single-crystal X-ray diffraction
analysis. The X-ray crystal structure of compound 3
(Fig. 1) shows that the (2-aminophenyl)phosphido
ligand behaves as a three electron-donor through the
phosphorus atom and no bonding interaction of the
amine moiety with the metal triangle is observed, which
is in contrast to the bonding mode found on the product
from the reaction of [Os3(CO)10(MeCN)2] and (2-
aminophenyl)diphenylphosphine, where the nitrogen
and phosphorus atoms are both coordinated [5].
[M3H(CO)10(PHPh)] (MꢀRu, Os) [11]. In 3, the 2-
aminophenyl group is approximately perpendicular to
the Os3 triangle (dihedral angle between the Os3 plane
/
and C6 ringꢀ
Thermolysis of either compound [Os3(CO)11{P(2-
NH2C6H4)H2}] (1) or
[Os3(m-H)(CO)10{m-P(2-
/
94.38).
NH2C6H4)H}] (3) in cyclohexane affords in quantitative
yields the nonacarbonyl species [Os3(m-H)2(CO)9{m3-
P(2-NH2C6H4)}] (4). Based on the IR, 1H and 31P
NMR spectra, we conclude that a phosphinidene moiety
is present, and the structure depicted by 4 in Scheme 1 is
the most likely; there is no spectroscopic evidence for
any interaction of the amino group with any other part
of the cluster.
The direct reaction of [Ru3(CO)12] and 2-aminophe-
nylphosphine in refluxing toluene gives only [Ru3(m-
H)2(CO)9{m3-P(C6H4NH2)}] (5) in high yield (Scheme
2).
The molecular structure of 3 is based on a triangle of
three osmium atoms, with two short OsÃ
Os(1)ÃOs(2)ꢀ2.891(2), Os(1)ÃOs(3)ꢀ2.894(1) A and
one longer bond, Os(2)ÃOs(3)ꢀ2.911(1) A, bridged by
the hydride and the phosphido group with Os(2)Ã
/Os bonds,
˚
/
/
/
/
˚
/
/
The 31P{1H} NMR spectrum displays a singlet at dꢀ
/
/
˚
P(1)ꢀ2.380(6) A (Table 2).
245 ppm, indicating the presence of a phosphinidene
1
moiety. In the H NMR spectrum the broad signal at
P(1)ꢀ
/
2.366(5) and Os(3)Ã
/
/
The 2-aminophenyl group points away from the
Os(CO)4 group and there is no short distance between
the NH2 group and either CO or metal. Its configura-
tion is the same found for related clusters such as
dꢀ
doublet at dꢀ
/
3.73 ppm is assigned to the NH2 protons and the
19.2 ppm to the 2 equiv. hydrides. The
/
ꢁ
/
close similarity of the IR spectra in the carbonyl region
Table 3
˚
Selected bond lengths (A) and angles (8) for compound 5
Bond lengths
Bond angles
Ru(1)Ã
Ru(1)Ã
Ru(2)Ã
Ru(1)Ã
Ru(2)Ã
Ru(3)Ã
C(1)Ã
/
Ru(2)
Ru(3)
Ru(3)
P(1)
2.8264(8)
2.9298(9)
2.9402(9)
2.2832(9)
2.298(1)
2.330(1)
1.797(3)
Ru(1)Ã
Ru(1)Ã
Ru(2)Ã
Ru(1)Ã
Ru(2)Ã
Ru(3)Ã
/
P(1)Ã
P(1)Ã
P(1)Ã
P(1)Ã
P(1)Ã
P(1)Ã
/
Ru(2)
Ru(3)
Ru(3)
C(1)
76.20(3)
78.85(3)
78.89(3)
132.1(1)
142.3(1)
125.1(1)
/
/
/
/
/
/
/
/
/
/P(1)
/
/C(1)
/P(1)
/
/C(1)
/
P(1)
Scheme 2.

A.J. Arce et al. / Inorganica Chimica Acta 344 (2003) 123Á
/127
127
Table 4
tances Ru(1)Ã
/
Ru(3)ꢀ
/
2.9298(9) and Ru(2)Ã
/
Ru(3)ꢀ
/
˚
2.9402(9) A supporting the bridging hydrides, while
Crystal data, data collection and refinement parameters for the
structures of [Os3(m-H)(CO)10{m-P(2-NH2C6H4)H}] (3), and [Ru3(m-
H)2(CO)9{m3-P(2-NH2C6H4)}] (5)
˚
Ru(2)ꢀ2.8264(8) A carries no
the short edge Ru(1)Ã
hydride.
/
/
Crystal parameters
Empirical formula
3
5
C
s3P
16H8NO10O-
C
PRu3
15.5H9ClNO9-
4. Supplementary material
Formula weight
Crystal color, habit
Crystal system
Space group
975.80
722.87
Yellow prism Yellow prism
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC Nos. 179300 and 179301 for
compounds 3 and 5, respectively. Copies of this
information may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge, CB2
monoclinic
C2/c
triclinic
¯
/
P1/
˚
a (A)
25.704(5)
8.770(2)
19.576(4)
90.00
8.822(2)
10.617(3)
12.716(3)
82.60(2)
74.389(17)
85.64(2)
1136.5(5)
2
˚
b (A)
˚
c (A)
a (8)
b (8)
99.45(3)
90.00
1EZ, UK (fax: ꢂ44-1223-336-033; e-mail: deposit@
/
g (8)
ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).
3
V (A )
˚
4353.0(15)
8
2.978
Z
Dcalc (g cmꢁ3
)
2.112
2.200
690
m (mmꢁ1
F(000)
)
17.596
3472
Acknowledgements
Crystal size (mm)
0.44ꢃ
0.38
4.22Á
/
0.40ꢃ
/
0.42ꢃ
0.25
4.80Á
/
0.42ꢃ
/
We are grateful to the British Council for support
through a British Council Academic Link between UCL
and IVIC groups and to FONACIT, Venezuela, for
projects S1-95000578, S1-96001062 and LAB-97000665.
2u Range (8)
Data collection and
/
50.00
/
53.0
refinement
Absorption correction
Empirical (DI- Psi-scan
FABS)
Reflections measured
Observed reflections
3927
3046
4955
4253
References
[criterion: Foꢀ4s(Fo)]
/
Unique reflections
Max/min transmission
Data-to-parameter ratio
Rint
3835 4692
0.0572/0.0400 0.5770/0.4340
[1] T.B. Rauchfuss, Inorg. Chem. 16 (1977) 2966.
[2] M.K. Cooper, P.A. Duckworth, T.W. Hambley, G.J. Organ, K.
Henrick, M. McPartlin, A. Parekh, J. Chem. Soc., Dalton Trans.
(1989) 1067.
13.6:1
0.0756
16.8:1
0.0090
R, wR, all data
R, wR, unique reflections
0.0958, 0.2700 0.0258, 0.0591
0.0787, 0.2573 0.0219, 0.0575
[3] G.J. Organ, M.K. Cooper, K. Henrick, M. McPartlin, J. Chem.
Soc., Dalton Trans. (1984) 2377.
Largest features in final difference 2.242/ꢁ
/
2.137 1.035/ꢁ0.670
/
[4] M.K. Cooper, J.M. Downes, Inorg. Chem. 17 (1978) 880.
[5] E.W. Ainscough, A.M. Brodie, S.L. Ingham, J.M. Waters, J.
Organomet. Chem. 468 (1994) 229.
ꢁ3
˚
map (max/min e A
)
[6] J.N. Nicholls, M.D. Vargas, Inorg. Synth. 26 (1989) 289.
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¨
of 4 and 5 (Table 1) shows that these are isostructural.
To confirm the mode of bonding of the ligand, an X-ray
structure analysis for compound 5 was undertaken. Its
molecular structure is shown in Fig. 2, and some
relevant bond lengths and angles are summarized in
Table 3.
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The molecular structure of 5 relates closely to that of
[Ru3(m-H)2(CO)9(m3-PPh)] [9] and it is as expected for a
[11] F. Iwasaki, M. Mays, P.R. Raithby, P.L. Taylor, P.J. Wheatley, J.
Organomet. Chem. 213 (1981) 185.
m3-phosphinidene complex with two long RuÃ
/Ru dis-