Preparation and organometallic complexes of the new unsymmetrical ligand: Ph2PNHC6H4PPh2

Article abstract of DOI:10.1016/S0022-328X(98)01189-9

Deprotonation of (2-diphenylphosphino)benzeneamine with BuLi followed by reaction with ClPPh₂ in THF gave Ph₂PNHC₆H₄PPh₂ in good yields. The new unsymmetrical ligand has been incorporated into a number of complexes [[Rh{Ph₂PNHC₆H₄PPh₂}(cod)][ClO ₄] 2, RhCl₂(η⁵-C₅Me₅){Ph ₂PNHC₆H₄PPh₂-P_(N)} 3, [RhCl(η⁵-C₅Me₅){Ph₂PNHC ₆H₄PPh₂-P_(N),P}][Cl] 4, IrCl₂(η⁵-C₅Me₅){Ph ₂PNHC₆H₄PPh₂-P_{N}} 5, RuCl₂(η⁶-MeC₆Hⁱ ₄Pr){Ph₂PNHC₆H₄PPh ₂-P_(N)} 6, [RuCl(η⁶-Me-C₆Hⁱ₄Pr) {Ph₂PNHC₆H₄PPh₂-P_(N), P }][BF₄] 7, RuCl₂(η⁶-C₆Me₆){Ph ₂PNHC₆H₄PPh₂-P_(N)} 8, [RuCl(η⁶-C₆Me₆) {Ph₂PNHC₆-H₄PPh₂-P _(N)P}][BF₄] 9, RuCl₂(η³:η³-C₁₀H ₁₆){Ph₂PNHC₆H₄PPh₂-P _(N)} 10, OsCl₂(η⁶-MeC₆Hⁱ ₄Pr){Ph₂NHPC₆H₄PPh ₂-P_(N)} 11] to demonstrate its coordination behaviour as a monodentate or as a chelate ligand. The X-ray structures of for 5, 9 and 10 are reported.

Full text of DOI:10.1016/S0022-328X(98)01189-9

Journal of Organometallic Chemistry 582 (1999) 83–89
Preparation and organometallic complexes of the new unsymmetrical
ꢀ
ligand: Ph2PNHC6H4PPh2
Stephen M. Aucott, Alexandra M.Z. Slawin, J. Derek Woollins *
Department of Chemistry, Loughborough Uni6ersity, Loughborough LE11 3TU, UK
Received 15 September 1998
Abstract
Deprotonation of (2-diphenylphosphino)benzeneamine with BuLi followed by reaction with ClPPh2 in THF gave
Ph2PNHC6H4PPh2 in good yields. The new unsymmetrical ligand has been incorporated into a number of complexes
[[Rh{Ph2PNHC6H4PPh2}(cod)][ClO4] 2, RhCl2(h5-C5Me5){Ph2PNHC6H4PPh2-P(N)
}
3, [RhCl(h5-C5Me5){Ph2PNHC6H4PPh2-
P
(N),P}][Cl] 4, IrCl2(h5-C5Me5){Ph2PNHC6H4PPh2-P{N}} 5, RuCl2(h6-MeC6Hi4Pr){Ph2PNHC6H4PPh2-P(N)} 6, [RuCl(h6-Me-
C6Hi4Pr){Ph2PNHC6H4PPh2-P(N),P}][BF4] 7, RuCl2(h6-C6Me6){Ph2PNHC6H4PPh2-P(N)
}
8, [RuCl(h6-C6Me6){Ph2PNHC6-
H4PPh2-P(N),P}][BF4] 9, RuCl2(h3:h3-C10H16){Ph2PNHC6H4PPh2-P(N)} 10, OsCl2(h6-MeC6H4i Pr){Ph2NHPC6H4PPh2-P(N)} 11] to
demonstrate its coordination behaviour as a monodentate or as a chelate ligand. The X-ray structures of for 5, 9 and 10 are
reported. © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Phosphine; X-ray structure; Heterocycle; Transition metal; Complex
tems so as to establish whether the difference in the
basicity/bulkiness of the phosphines could be employed
to enable the ligands to be switched between monoden-
tate and bidentate coordination behaviour, i.e. to gen-
erate ‘hemilabile’ bisphosphines with properties similar
to other reported examples [10–12].
1. Introduction
We have recently reported a number of syntheses of
new P–N–P ligands [1–3] and phosphines [4–6] via
simple P–N bond forming reactions. Apart from ligand
systems with totally non-carbon backbones we have
been able to synthesise the first six-membered true
heterocycles [7]. Surprisingly, there have been few re-
ports on non-carbon spacers between the carbon back-
bone and the adjacent phosphine centres in bidentate
phosphine, we have been able to prepare simple biden-
tate systems from reactions with diaminotoluene [8].
Here we report on the formation of a simple unsym-
metric bis-phosphines obtained from the reaction of
(2-diphenylphosphino)benzeneamine [9] with BuLi fol-
lowed by Ph2PCl. We decided to investigate these sys-
2. Experimental
2.1. General
Diethyl ether, petroleum ether (60–80°C) and THF
were purified by reflux over sodium and distillation
under nitrogen. Dichloromethane was heated to reflux
over powdered calcium hydride and distilled under
nitrogen. [{Rh(m-Cl)(cod)}2] [13], [{MCl(m-Cl)(h5-
ꢀ Dedicated to Alan Cowley, on the occasion of his 65th birthday.
Although we were only briefly colleagues, Alan has been a significant
influence on much of our work.
* Corresponding author.
E-mail address: j.d.woollins@lboro.ac.uk (J.D. Woollins)
C5Me5)}2]
M=Rh,
Ir
[14],
[{RuCl(m-Cl)(h6-
MeC6Hi4Pr)}2] [15], [{RuCl(m-Cl)(h6-C6Me6)}2] [15],
and [{RuCl(m-Cl)(h3:h3-C10H16)}2] [16] were prepared
as described in the literature. IR spectra were recorded
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(98)01189-9

84
S.M. Aucott et al. / Journal of Organometallic Chemistry 582 (1999) 83–89
4
31
from KBr discs on a Perkin–Elmer system spectrome-
ter; 31P-NMR spectra on a Jeol FX90Q operating at
36.21 MHz; 1H-, 13C- and 31P-NMR spectra on a
Bruker AC250 operating at 250, 62.9 and 101.3 MHz,
respectively. Fast atom bombardment mass spectra
were carried out by the Swansea mass spectrometer
service.
l(PX) 29.6(d) ppm. J(31P PX) 3.7 Hz. FAB+ MS:
A−
m/z 461, [M]+. IR (KBr): 3300vs, 3059m, 1587s, 1566s,
1474s, 1433s, 1372s, 1286m, 1261m, 1090m, 1025vs,
997vs, 891s, 849s, 781vs, 755vs, 743m, 696s, 545s,
516vs, 496m, 469vs 447s, 419s, 393s, 282vs cm−1
.
2.1.2. [Rh{Ph2PNHC6H4PPh2}(cod)][ClO4] 2
Care: perchlorate salts may be explosive. [{Rh(m-
Cl)(cod)}2] (0.126 g, 0.26 mmol) and AgClO4 (0.107 g,
0.52 mmol) were weighed into a 50 cm3 round bot-
tomed Schlenk flask. The flask was evacuated, then
filled with N2. Degassed acetone (30 cm3) was added
and the mixture was stirred for 30 min giving AgCl as
a white precipitate. The solution was transferred by a
filter stick to a second flask (also filled with N2) con-
taining 1 (0.238 g, 0.52 mmol). The mixture was stirred
under an N2 atmosphere for 1 h and concentrated in
vacuo to ca. 15 cm3. Light petroleum (25 cm3) was
added to precipitate the product and the flask was
stored at −4°C over night. The dark orange solid was
collected by suction filtration washed with light
petroleum (2×15 cm3) and dried in vacuo. Yield 0.32
2.1.1. Ph2PNHC6H4PPh2 1
n
A solution of 2.43 M BuLi (13 cm3, 31.6 mmol) in
hexane was added dropwise over a period of 10 min to
a cooled (−78°C cardice/acetone) stirred solution of
(2-diphenylphosphino)benzeneamine [9] (8.7 g, 31.4
mmol) in freeze/thaw degassed THF (350 cm3). The
clear pale orange solution was warmed to room temper-
ature (r.t.) and stirred for 30 min giving a light, white
precipitate. The reaction was cooled once more to
−78°C (cardice/acetone) and
a
solution of
chlorodiphenylphosphine (5.7 cm3, 7.0 g, 31.7 mmol) in
freeze/thaw degassed THF (50 cm3) was added drop-
wise over a period of 5 min and the mixture was
allowed to warm to r.t., then stirred for 1 h. The
solvent was removed in vacuo and the pale brown oil
was taken up in a minimum amount of acetone (ca. 50
cm3). Distilled water was added dropwise (ca. 20 cm3)
to precipitate the product. The colourless solid was
collected by suction filtration, washed with ice cold
methanol (20 cm3) and dried overnight in vacuo. Yield
10.5 g, 73%. Microanalysis: Found (Calc. for
C30H25NP2). C, 78.08 (76.99); H, 5.46 (5.53); N, 3.04
(3.35)%. 31P{H}-NMR (CDCl3): l(PA) −19.5(d),
g,
81%.
Microanalysis:
Found
(Calc.
For
C38H37ClNO4P2Rh). C, 59.01 (59.12); H, 4.62 (4.83); N,
1.47 (1.81)%. 31P{H}-NMR (CDCl3): l(PA) 17.5(dd)
ppm. 1J(103Rh−31PA) 136 Hz. l(PX) 71.9(dd) ppm.
1J(103Rh−31PX) 158 Hz. 2J(31PA−31PX) 52.8 Hz.
FAB+ MS: m/z 672, [M]+. IR (KBr): 3248br, 3056s,
1697br, 1625br, 1591s, 1482vs, 1437vs, 1311m, 1271m,
1228m, 1096br, 998s, 938s, 750s, 727vs, 695vs, 623vs,
527br, 497s cm−1
.
Table 1
Details of the crystal data and refinements
Compound
5
9
10
Empirical formula
Formula weight
Colour
C40.75H41.5Cl3.5IrNP2
923.5
Yellow
C42.5H43.5BCl2.5F4N2P2Ru
920.7
C40H41Cl2NP2Ru
769.7
Yellow
0.4×0.35×0.2
Monoclinic
P21
13.3780(2)
10.3410(1)
13.5412(1)
102.951(1)
1826
Yellow
0.01×0.06×0.08
Monoclinic
P21/n
15.3659(3)
17.7795(2)
16.0576(3)
100.633(1)
4311
Size (mm)
0.2×0.25×0.3
Monoclinic
P21/n
10.4389(2)
17.1933(2)
22.7357(1)
103.117(1)
3974
Crystal system
Space group
˚
a (A)
˚
b (A)
˚
c (A)
i (°)
V (A )
3
˚
Z
4
1.54
3.70
1838
4
1.42
0.64
1880
2
1.40
0.69
792
Dcalc. (g cm−3
)
m(Mo–Ka) (mm−1
F(000)
)
Independant reflections
Observed reflections
Final R1 [I\2|(I)]
wR2
9220
9171
0.0344
0.0827
0.922
1.18 and −0.87
6166
6100
0.0852
0.1805
1.038
0.96 and −0.74
8098
4852
0.0330
0.0839
0.944
0.49 and −0.23
Goodness of fit on F2
−3
˚
Largest difference peak/hole (e A
)

S.M. Aucott et al. / Journal of Organometallic Chemistry 582 (1999) 83–89
85
Fig. 1. 31P{H}-NMR of complexes 3 (top) and 4 (bottom).
2.1.3. RhCl2(p5-C5Me5){Ph2PNHC6H4PPh2-P(N)} 3
[{RhCl(m-Cl)(h5-C5Me5)}2] (0.090 g, 0.15 mmol) was
suspended in THF (1.5 cm3). To the stirred suspension
was added 1 (0.140 g, 0.30 mmol) as a solid. The
suspension dissolved and the product 3 precipitated.
After stirring for ca. 90 min, the dark red solid was

86
S.M. Aucott et al. / Journal of Organometallic Chemistry 582 (1999) 83–89
Table 2
Comparison of 31P-NMR spectroscopic data for monodentate and chelate complexes
Monodentate ligand
Chelating ligand
lPA
lPX
4J{31P−31P}
lPA
lPX
2J{31P−31P}
3
5
6
8
11
−22.7
−22.6
−21.8
−24.5
−21.6
56.3
23.8
53.1
56.7
11.4
8.8
7.6
8.5
8.9
8.6
4
31.9
−6.4
34.8
35.8
−10.8
75.4
37.7
81.6
81.2
36.8
80.3
48.4
75.7
83.6
48.4
a
7
9
a
a NMR only—sample not isolated.
collected by suction filtration and washed with diethyl
1095s, 1062s, 1026s, 999s, 910s, 779m, 749vs, 701s,
620vs, 613vs, 526vs, 513vs, 494vs, 474vs, 441s, 297s,
ether (2×10 cm3) and dried in vacuo. Yield 0.20 g,
89%.
Microanalysis:
Found
(Calc.
for
273s cm−1
.
C40H40Cl2NP2Rh). C, 62.10 (62.35); H, 5.61 (5.23); N
1.97 (1.82)%. 31P{H}-NMR (toluene/C6D6): l(PA) −
22.7(d) ppm. l(PX) 56.3(dd) ppm. 1J(103Rh−31PX)
151.1 Hz. 4J(31PA−31PX) 8.8 Hz. IR (KBr): 3279m,
3051s, 2910m, 2863s, 1585vs, 1570vs, 1503m, 1476vs,
1435vs, 1383vs, 1277vs, 1216s, 1186m, 1159m, 1093s,
1062vs, 1025m, 909vs, 773m, 750vs, 701vs, 619vs,
2.1.6. RuCl2(p6-MeC6Hi4Pr){Ph2PNHC6H4PPh2-P(N)
6
}
This was prepared in the same way as the rhodium
compound
3
using [{RuCl(m-Cl)(h6-MeC6H4i Pr)}2]
(0.074 g, 0.12 mmol) in THF (1.5 cm3) and 1 (0.115 g,
0.25 mmol). The red/brown product was collected by
suction filtration, dissolved in CH2Cl2 (5 cm3) and
filtered through celite to remove some insoluble mate-
rial. Light petroleum (25 cm3) was added and the
volume was reduced in vacuo to ca. 10 cm3. The
orange/red product was collected by suction filtration
and dried in vacuo. Yield 0.15 g, 83%. Microanalysis:
Found (Calc. for C40H39Cl2NP2Ru). C, 62.69 (62.58);
H, 5.37 (5.12); N, 1.92 (1.82)%. 31P{H}-NMR (CDCl3):
l(PA) −21.8(d), l(PX) 53.1(d) ppm. 4J(31PA−31PX) 8.5
Hz. FAB+ MS: m/z 768, [M+H]+. IR (KBr): 3242s,
3048s, 3033s, 2956s, 2868m, 1585s, 1567s, 1478vs,
1437vs, 1401vs, 1287vs, 1228m, 1183m, 1161vs, 1125s,
1093vs, 1071s, 1056s, 1027vs, 999vs, 925m, 875vs, 783s,
613vs, 522vs, 492s, 473vs, 449s, 397br cm−1
.
2.1.4. [RhCl(p5-C5Me5){Ph2PNHC6H4PPh2-P(N),P}]-
[Cl] 4
Compound 3 (0.103 g, 0.13 mmol) was stirred in
chloroform (4 cm3) for 2 h, diethyl ether (25 cm3) was
added to precipitate a bright orange coloured solid. The
product was collected by suction filtration washed with
diethyl ether (2×10 cm3) and dried in vacuo. Yield
0.91 g, 91%. Microanalysis: Found (Calc. for
C40H40Cl2NP2Rh). C, 62.67 (62.35); H, 5.74 (5.32); N,
1.66 (1.82)%. 31P{H}-NMR (CDCl3): l(PA) 31.9(dd)
1
ppm. J(103Rh−31PA) 124.2 Hz. l(PX) 75.4(dd) ppm.
1J(103Rh−31PX) 135.2 Hz. 2J(31PA−31PX) 80.3 Hz.
FAB+ MS: m/z 734 corresponds to [RhCl(h5-
C5Me5){Ph2PC6H4NHPPh2}]+, 699 corresponds to
[Rh(h5-C5Me5){Ph2PC6H4NHPPh2}]+.
IR
(KBr):
3052s, 1624br, 1590vs, 1503s, 1457s, 1435vs, 1376s,
1318m, 1260m, 1225m, 1188s, 1158m, 1134m, 1096vs,
1074s, 1018m, 999vs, 868br, 749vs, 696vs, 602m, 537vs,
523vs, 511vs, 483vs, 446br, 374br cm−1
.
2.1.5. IrCl2(p5-C5Me5){Ph2PNHC6H4PPh2-P{N}} 5
This was prepared in the same way as the rhodium
compound 3 using [{IrCl(m-Cl)(h5-C5Me5)}2] (0.070 g,
0.09 mmol) in THF (1.5 cm3) and 1 (0.084 g, 0.18
mmol) to give a bright orange solid. Yield 0.13 g, 87%.
Microanalysis: Found (Calc. for C40H40Cl2IrNP2). C,
55.71 (55.88); H, 4.82 (4.69); N, 1.80 (1.63)%. 31P{H}-
NMR (CDCl3): l(PA) −22.6(d), l(PX) 23.8(d) ppm.
4J(31PA−31PX) 7.6 Hz. FAB+ MS: m/z 858, [M–H]−.
IR (KBr): 3286s, 3052s, 2975m, 2911m, 2862m, 1585s,
1568s, 1475s, 1435s, 1383s, 1278vs, 1217s, 1186s, 1160s,
Fig. 2. The X-ray structure of 5.

S.M. Aucott et al. / Journal of Organometallic Chemistry 582 (1999) 83–89
87
Table 3
˚
Comparative selected bond lengths (A) and angles (°) for 5, 9 and 10
5
9
10
˚
Bond length (A)
M–P(1)
2.3113(11)
1.691(3)
1.423(5)
1.427(6)
1.841(4)
–
2.331(3)
1.681(8)
1.435(13)
1.394(14)
1.823(10)
2.307(3)
2.382(3)
–
2.440(1)
1.671(3)
1.421(6)
1.406(6)
1.832(5)
–
P(1)–N(1)
N(1)–C(1)
C(1)–C(2)
C(2)–P(2)
M–P(2)
M–Cl(1)
M–Cl(2)
2.425(1)
2.401(1)
2.422(1)
2.406(1)
Bond angle (°)
M–P(1)–N(1)
P(1)–N(1)–C(1)
N(1)–C(1)–C(2)
C(1)–C(2)–P(2)
C(2)–P(2)–M
P(2)–M–P(1)
110.3(1)
130.0(3)
118.7(4)
118.8(3)
–
115.6(3)
127.2(7)
120.4(9)
117.4(8)
115.1(3)
85.0(1)
112.1(1)
130.1(3)
119.2(4)
117.9(3)
–
Fig. 3. The X-ray structure of 9.
–
–
745vs, 697vs, 612vs, 523vs, 490vs, 472vs, 452s, 430m,
299br cm−1
.
862br, 799vs, 749vs, 696vs, 612vs, 528vs, 476vs, 457s
cm−1
2.1.7. [RuCl(p6-MeC6H4i Pr){Ph2PNHC6H4PPh2-P(N),
P}][BF4] 7
-
.
2.1.8. RuCl2(p6-C6Me6){Ph2PNHC6H4PPh2-P(N)} 8
This was prepared in the same way as the rhodium
compound 3 using [{RuCl(m-Cl)(h6-C6Me6)}2] (0.090 g,
0.13 mmol) in THF (3 cm3) and 1 (0.126 g, 0.27 mmol).
The mixture was stirred for 18 h. The brown solid was
collected by suction filtration, dissolved in DCM (5
cm3) and filtered through celite to remove some black
insoluble material. Light petroleum (25 cm3) was added
and the volume was reduced in vacuo to ca. 10 cm3.
The red product was collected by suction filtration and
dried in vacuo. Yield 0.19 g, 90%. Microanalysis:
Found (Calc. for C42H43Cl2NP2Ru). C, 63.66 (63.40);
H, 5.71 (5.45); N, 1.98 (1.76)%. 31P{H}-NMR (CDCl3):
l(PA) −24.5(d), l(PX) 56.7(d) ppm. 4J(31PA−31PX) 8.9
Hz. FAB+ MS: m/z 760, [M–Cl]+. IR (KBr): 3261m,
34051m, 2914br, 1622vs, 1586vs, 1569vs, 1478vs,
1435vs, 1385vs, 1281vs, 1220m, 1184m, 1162m, 1102s,
1090s, 1070vs, 1072vs, 903m, 783s, 744vs, 695s, 620vs,
Compound 6 (0.114 g, 0.15 mmol) and AgBF4 (0.029
g, 0.15 mmol) were weighed into a Schlenk tube. The
tube was sealed with a septum evacuated then filled
with nitrogen. Degassed dichloromethane (5 cm3) was
added and the mixture was stirred for 5 h. AgCl was
removed by filtration through a Celite pad and the
volume was reduced to ca. 1–2 cm3. Addition of diethyl
ether (20 cm3) gave a brown precipitate. The crude
product was recrystallised from a minimum of chloro-
form and the red crystalline material was collected by
suction filtration and dried in vacuo. Yield 0.75 g, 62%.
Microanalysis: Found (Calc. for C40H39BCl2FNP2Ru).
C, 58.94 (58.66); H, 4.96 (4.80); N, 1.77 (1.71)%.
31P{H}-NMR (CDCl3): l(PA) 35.4(d), l(PX) 82.5(d)
ppm. 2J(31PA−31PX) 78.1 Hz. FAB+ MS: m/z 732,
[M]+. IR (KBr): 3283br, 3056m, 2965m, 1625br,
1587vs, 1568vs, 1479vs, 1437vs, 1390s, 1288s, 1231s,
1187s, 1164s, 1097m, 1083m, 1061br, 998s, 915m,
537vs, 524vs, 490vs, 470vs, 455vs, 436s cm−1
.
2.1.9. [RuCl(p6-C6Me6){Ph2PNHC6H4PPh2-P(N),P}]-
[BF4] 9
This was prepared in the same way as the ruthenium
compound 7 using 8 (0.119 g, 0.15 mmol) and AgBF4
(0.029 g, 0.15 mmol). The crude product was recrys-
tallised from the minimum of chloroform and the or-
ange crystalline product was collected by suction
filtration and dried in vacuo. Yield 0.83 g, 66%. Micro-
analysis: Found (Calc. for C42H43BCl2FP2Ru). C, 59.77
(59.55); H, 5.47 (5.12); N, 1.60 (1.65)%. 31P{H}-NMR
2
(CDCl3): l(PA) 36.3(d), l(PX) 82.5(d) ppm. J(31PA−
31PX) 73.6 Hz. FAB+ MS: m/z 760, [M]+. IR (KBr):
3299m, 3056m, 1618br, 1587s, 1483vs, 1450vs, 1437vs,
Fig. 4. The X-ray structure of 10.

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S.M. Aucott et al. / Journal of Organometallic Chemistry 582 (1999) 83–89
1387m, 1316m, 1295s, 1280m, 1232s, 1188m, 1164m,
1096s, 10765br, 914vs, 873s, 801m, 763vs, 747vs, 728s,
699s, 647s, 595m, 538vs, 520vs, 486vs, 458s, 443s, 356br
3. Results and discussion
The synthesis of bidentate phosphine ligands with
aromatic backbones/spacer groups is well established
[18]. However, rather less is known about diphosphines
with non-organic backbones. Baker and Pringle have
described the preparation of a chiral metal phosphite
ligand starting from phosphinolphenol [19]. We have
previously described the synthesis of a symmetric bis-
phosphine from diamino-toluene [8] and there has been
a report on the cyclisation of anilino-phosphine to give
1,2,3-benzadiphosphole [20]. Here we report on the
facile synthesis of an unsymmetric diphosphine together
with demonstrative organometallic complexes. Thus de-
protonation of (2-diphenylphosphino)benzeneamine
with BuLi followed by reaction with PPh2Cl (Eq. 1) in
THF gave Ph2PNHC6H4PPh2 1 in a good yield (73%).
cm−1
.
2.1.10. RuCl2(p3:p3-C10H16){Ph2PNHC6H4PPh2-P(N),
}
10
This was prepared in the same way as the rhodium
compound 3 using [{RuCl(m-Cl)(h3:h3-C10H16)}2] (0.117
g, 0.19 mmol) and 1 (0.175 g, 0.38 mmol) in THF (4
cm3). The mixture was stirred for 2 h giving a dark
yellow solution which was filtered through a small celite
plug and precipitated by the slow addition of diethyl
ether (40 cm3). The yellow product was collected by
suction filtration and dried in vacuo. Yield 0.222 g, 87%.
Microanalysis: Found (Calc. for C40H41Cl2NP2Ru). C,
61.97 (62.42); H, 5.31 (5.37); N, 1.63 (1.82)%. 31P{H}-
NMR (CDCl3): l(PA) −20.3(d), l(PX) 34.6(d) ppm.
2J(31PA−31PX) 13.2 Hz. FAB+ MS: m/z 858, [M+
H]+. IR (KBr): 3170br, 3050vs, 2912m, 2855m, 1583vs,
1568vs, 1475vs, 1435vs, 1383vs, 1220s, 1089s, 1026vs,
915s, 856m, 785s, 760vs, 749vs, 698s, 611vs, 526vs,
(1)
The new phosphine gave the expected AX type 31P-
NMR and we assign PA (l= −19.5 ppm) as the triaryl
phosphine [(2-diphenylphosphino)benzeneamine has
l=21 ppm] and PX (l=29.6 ppm) as the N–PPh2
group end of the molecule (cf. MeC6H4(NHPPh2)2
which has l=33.3, 30.4 ppm). Reaction of 1 with a
range of organometallic halo complexes proceeds
smoothly (Eq. 2). All of the new complexes gave satis-
factory microanalyses, mass spectral data (including
469vs, 420s, 390s, 331m, 310s, 229vs, 224vs cm−1
.
2.1.11. OsCl2(p6-MeC6Hi4Pr){Ph2NHPC6H4PPh2-P(N)
}
11
This was prepared in the same way as the rhodium
compound 3 using [{OsCl(m-Cl)(h6-MeC6H4i Pr}2] (0.051
g, 0.065 mmol) in THF (2 cm3) and 1 (0.060 g, 0.13
mmol). The mixture was stirred for 18 h. Light
petroleum (15 cm3) was added to further precipitate the
product. The orange solid was collected by suction
filtration and dried in vacuo. Yield 0.10 g, 90%. Micro-
analysis: Found (Calc. for C40H39Cl2NOsP2). C, 56.41
(56.07); H, 4.42 (4.59); N, 1.47 (1.63)%. 31P{H}-NMR
(CDCl3): l(PA) −21.6(d), l(PX) 11.4(d) ppm.
4J(31PA−31PX) 8.6 Hz. FAB+ MS: m/z 734, [M–H]+.
IR (KBr): 3243m, 3046s, 3026s, 2956s, 1585vs, 1567vs,
1479vs, 1437vs, 1402vs, 1288s, 1183m, 1160s, 1094vs,
1027vs, 924s, 879vs, 745vs, 697vs, 613vs, 525vs, 490vs,
isotopomer distributions) and 31P- and H-NMR data.
1
Interestingly, not all of the initial products obtained
involve bidentate coordination of 1. Thus, while bridge
cleavage of [{Rh(m-Cl)(cod)}2] gave the anticipated
product [Rh}Ph2PNHC6H4PPh2}(cod)][ClO4] 2, the re-
action with [{RhCl(m-Cl)(h5-C5Me5)}2] gave {RhCl2(h5-
C5Me5){Ph2PNHC6H4PPh2-P(N)} 3, which only involves
coordination via the N–PPh2 end of the bis-phosphine.
Similar results were obtained with [{Ir(Cl)(m-Cl)(h5-
C5Me5)}2], [{RuCl(m-Cl)(h6-MeC6H4i Pr}2], [{RuCl(m-
Cl)(h6-C6Me6)}2], [{RuCl(m-Cl)(h3:h3-C10H16)}2] and
[{OsCl(m-Cl)(h6-MeC6H4i Pr}2]. Stirring the monoden-
tate rhodium complex 3 in chloroform for a few hours
results in conversion to the corresponding bidentate
complex while the other monodentate complexes un-
dergo the analogous conversion (Eq. 2, Fig. 1) when
stirred in MeOH/CHCl3.
473vs, 451vs, 433s, 399s, 305vs, 279s, 229vs cm−1
.
2.2. Crystallography
Crystallography was performed using a Siemens
SMART diffractometer; full hemisphere of data with
0.3° ‘slices’, r.t., Mo–Ka radiation and empirical ab-
sorption corrections. In 9 the half weight chloroform
solvate was refined in two occupancies with 30 and 20%
occupancies with the lower occupancy sites being refined
isotropically, all of the other non-H atoms were refined
anisotropically. In 10 the chirality was established from
the Flack parameter [0.02(3)]. All calculations employed
the SHELXTL program system [17]. Details of crystal
data and refinement for compounds 5, 9 and 10 are
shown in Table 1.
(2)

S.M. Aucott et al. / Journal of Organometallic Chemistry 582 (1999) 83–89
89
Alternatively, bidentate coordination can be induced by
removal of a coordinated chloride using Ag+. Selected
NMR parameters for the monodentate and bidentate
complexes are given in Table 2. We suppose that the
monodentate complexes prefer to use the N–PPh2
phosphine for coordination on simple steric grounds,
though we cannot exclude any electronic effects. The
observation of initial monodentate coordination sup-
ports the idea that these unsymmetrical ligands could
be used as ‘hemilabile’ systems.
As part of the characterisation of the new complexes
and to further confirm our conclusions about the bind-
ing modes we determined the crystal structures of three
representative examples (Figs. 2–4). The X-ray struc-
tures of 5 and 10 reveal the expected monodentate
N–PPh2 coordination mode while that of 9 confirms
bidentate coordination. The M–P bond lengths are in
the expected range; interestingly upon chelation M–
P(1) appears somewhat shorter than in the monoden-
obtained free of charge from The Director, CCDC, 12
Union Road, Cambridge, CB2 1EZ UK. (Fax: +44-
1223-336-033 or e-mail: deposit@ccdc.cam.ac.uk or
www: http://www.ccdc.cam.ac.uk).
Acknowledgements
We are grateful to the JERI for an equipment grant
and to Dr J. Parr for providing the osmium starting
material.
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4. Supplementary material
Crystallographic data for the structural analyses has
been deposited with the Cambridge Crystallographic
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103144 for 10. Copies of this information may be
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.