The preparation and coordination chemistry of phosphorus(III) derivatives of dialkyl hydrazines

Article abstract of DOI:10.1039/b107072j

The formation of the new inorganic hydrazine based ligands R₂PNR′NR′PR₂ [R′ = Et, R = Cl, Ph, OPh, CH₂Ph, o-MeOC₆H₄: R′ = Me, R = o-MeC₆H₄, o-MeOC₆H₄] is re

Full text of DOI:10.1039/b107072j

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The preparation and coordination chemistry of phosphorus(III)
derivatives of dialkyl hydrazines
Alexandra M. Z. Slawin, Matthew Wainwright and J. Derek Woollins*
Department of Chemistry, University of St Andrews, St Andrews, Fife, UK KY16 9ST.
E-mail: jdw3@st-and.ac.uk
Received 6th August 2001, Accepted 12th November 2001
First published as an Advance Article on the web 16th January 2002
The formation of the new inorganic hydrazine based ligands R2PNRЈNRЈPR2 [RЈ = Et, R = Cl, Ph, OPh, CH2Ph,
o-MeOC6H4: RЈ = Me, R = o-MeC6H4, o-MeOC6H4] is reported. These ligands have been complexed at Pd() and
Pt() centres and demonstrative X-ray structures have been determined. When R = o-MeOC6H4 the oxygen atoms
of two of the OMe groups coordinate pseudo axially.
Since the discovery of bis(dihalophosphino)amines, X2PN-
(R)PX2,1–3 extensive research has been carried out on the main
group and transition metal/organometallic chemistry of this
type of ligand system.1–16 This is in sharp contrast to the corre-
sponding studies of the dinitrogen-bridged diphosphines, bis-
(dihalophosphino)hydrazines, X2PN(R)N(R)PX2, which, until
recent work by Reddy and Katti,17–19 has been limited to a few
reports.20,21 The development of the chemistry of bis(dihalo-
phosphino)hydrazine ligands is of particular significance
because they have a similar chain length to that of dppe, a
ligand which has proved adept at forming five-membered
chelate rings and has demonstrated significant applications in
catalytic systems. The reactivity of the halide substituents on
these ligands may also be utilised in the development of a
wide range of RЈ2PN(R)N(R)PRЈ2-type derivatives, allowing
excellent control of the steric and electronic properties of any
subsequent ligands. The studies reported by Reddy and Katti
have centred on the synthesis and coordination chemistry of
derivativesofbis(dichlorophosphino)dimethylhydrazine,Cl2PN-
(Me)N(Me)PCl2. We have studied the dimethyl and diethyl-
hydrazine, and here report on the effects changes in the sub-
stituent groups have on the coordination chemistry of such
ligands. We have also synthesised a number of derivatives of
Cl2PN(Me)N(Me)PCl2 containing phenyl groups with OMe
in the ortho position to investigate the possibility of these
substituents occupying sites above and below metal centres
in complexes, thus limiting the available approach routes of
reactants in catalytic systems.
viscous orange suspension. The reaction mixture is then heated
under reflux for 96 hours and the excess PCl3 removed in vacuo
to leave a viscous orange oil. Kugelrohr distillation of the crude
product leaves 1 as a colourless oil in good yield (72%). The 31P-
{1H} NMR spectrum of 1 shows a singlet at δ(P) 156, an upfield
shift of approximately 4 ppm from the value reported for Cl2-
PN(Me)N(Me)PCl2,17 and FABϩ mass spectrometry shows the
expected parent-ion peak (m/z 290 [M]ϩ). Elemental analysis is
in good agreement with the calculated values and the IR spec-
trum shows a band at 952 cmϪ1 that can be assigned to ν(PN).
Having successfully synthesised Cl2PN(Et)N(Et)PCl2 we were
then able to use this compound as a chloro precursor in
nucleophilic substitution reactions and reactions with Grignard
reagents to produce a range of aryloxy- and aryl-substituted
phosphorus() hydrazides.
Reaction of Cl2PN(Et)N(Et)PCl2 with four equivalents of
PhOH in the presence of Et3N in hexane proceeds smoothly to
yield the aryloxy-functionalised ligand (PhO)2PN(Et)N(Et)-
P(OPh)2 2. Dropwise addition of a hexane solution of phenol
and triethylamine to a stirred hexane solution of Cl2PN(Et)-
N(Et)PCl2 results in the immediate precipitation of [NEt3H]Cl
as the reaction proceeds. Stirring is continued for a further 12
hours. Removal of the ammonium salt by suction filtration and
removal of the solvent in vacuo leaves 2 as a colourless viscous
oil in good yield (81%). The 31P-{1H} NMR spectrum of 2
consists of a single resonance at δ(P) 139, the difference in
chemical shift between it and 1 (17 ppm) being comparable to
that observed between Cl2PN(Me)N(Me)PCl2 and (PhO)2P-
N(Me)N(Me)P(OPh)2.17,18 Elemental analysis is in agreement
with calculated values and FABϩ mass spectrometry shows the
expected parent-ion peak (m/z 520 [M]ϩ). The IR spectrum of 2
shows bands which can be assigned to ν(PN) and ν(PO) (930
and 1030 cmϪ1 respectively).
Reaction of Cl2PN(Et)N(Et)PCl2 1 with four equivalents of
RMgBr (R = Ph or CH2Ph), in diethyl ether yields the diphos-
phines Ph2PN(Et)N(Et)PPh2 3 and (PhCH2)2PN(Et)N(Et)-
P(CH2Ph)2 4 as colourless and pale yellow solids in good yields
(70 and 74% respectively). FABϩ mass spectrometry shows
peaks corresponding to the parent-ion peaks [M]ϩ (m/z 456 for
3 and 512 for 4) and the IR spectra contain bands which can be
assigned to ν(PN) (970 for 3 and 962 cmϪ1 for 4) The 31P-{1H}
NMR spectra of the two compounds show singlets at δ(P) 64.2
and 64.8 respectively, significantly further upfield than the value
for 2 due to the lack of highly electronegative oxygen atoms
close to the phosphorus centres. Elemental analyses are in good
agreement with calculated values.
Results and discussion
As mentioned above Katti has reported the synthesis of Cl2PN-
(Me)N(Me)PCl2 from the reaction of 1,2-dimethylhydrazine
dihydrochloride and phosphorus trichloride.17 Employing a
similar technique we were able to synthesise the analogous
diphosphine, Cl2PN(Et)N(Et)PCl2 1, from the reaction of 1,2-
diethylhydrazine dihydrochloride and phosphorus trichloride
[eqn. (1)].
(1)
Dropwise addition of PCl3 to a finely ground sample of 1,2-
diethylhydrazine dihydrochloride results in the formation of a
DOI: 10.1039/b107072j
J. Chem. Soc., Dalton Trans., 2002, 513–519
This journal is © The Royal Society of Chemistry 2002
513

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A series of ligands containing phenyl groups with sub-
stituents in the ortho position have also been successfully syn-
thesised. Reaction of the chloro precursor 1 with the Grignard
reagent o-anisylmagnesium bromide, o-CH3OC6H4MgBr, gen-
erates (o-C6H4OCH3)2PN(Et)N(Et)P(o-C6H4OCH3)2 5, while
reaction of Cl2PN(Me)N(Me)PCl2 with o-anisylmagnesium
bromide or o-tolylmagnesium chloride, o-CH3C6H4MgCl,
yields (o-C6H4OCH3)2PN(Me)N(Me)P(o-C6H4OCH3)2 6 and
(o-C6H4CH3)2PN(Me)N(Me)P(o-C6H4CH3)2
7
respectively
[eqn. (2)].
(2)
Fig. 1 The solid state structure of 8.
from the PdP2Cl2 planes of 0.04 and 0.02 Å]. The PdP2N2 rings
have a classic open envelope conformation. In the Pd(1)–P(1)–
N(1)–N(2)–P(2) ring N(2) is out of the plane by 0.59 Å and
in the Pd(2)–P(3)–N(3)–N(4)–P(4) ring N(3) and N(4) lie above
the coordination plane by 0.41 and 0.72 Å respectively. The
P–N, Pd–Cl and Pd–P bond lengths are similar to values pre-
viously reported for single bonds in the related chelate complex
cis-[PdCl2{(p-BrC6H4O)2PN(Me)N(Me)P(OC6H4Br-p)2}],19
although the P–N bond lengths are considerably shorter than
those observed in 14 (vide infra) and the chelate urea based
complexes we have previously reported.22
The 31P-{1H} NMR spectra of 5 and 6 show singlets at δ(P)
40.5 and 42.6 respectively and the FABϩ mass spectra contain
peaks corresponding to [M]ϩ (m/z 576 for 5 and 549 for 6). The
IR spectra of both compounds show a band which can be
assigned to ν(PN) (933 for 5 and 969 cmϪ1 for 6) and elemental
analyses are in agreement with calculated values. As with 5 and
6 the 31P-{1H} NMR spectrum of 7 indicates the presence of a
single phosphorus species, represented by a singlet at δ(P) 47.2
and the FABϩ mass spectrum shows a peak which corresponds
to the parent-ion (m/z 485 [M]ϩ).
The R2PNRЈNRЈPR2 ligands described above are all stable in
air as solids though the chloro starting material 1 hydrolyses
rapidly in air.
Ph2PN(Et)N(Et)PPh2 also reacts with equimolar quantities
of [PtCl2(cod)] and [PdCl2(cod)] to yield five-membered P,PЈ
chelates [eqn. (4)] to give 10 and 11.
Katti has reported the synthesis of various metal complexes
in which diphosphine derivatives of Cl2PN(Me)N(Me)PCl2 act
as P,PЈ chelates.17–19 Here we describe the synthesis of metal
complexes containing derivatives of Cl2PN(Et)N(Et)PCl2 act-
ing as P,PЈ chelates, as well as further examples involving
derivatives of Cl2PN(Me)N(Me)PCl2.
(4)
The reaction of (PhO)2PN(Et)N(Et)P(OPh)2 2 with equi-
molar quantities of [PtCl2(cod)] or [PdCl2(cod)] (cod = cyclo-
octa-1,5-diene) in dichloromethane proceeds according to eqn.
(3) to yield the five-membered, P,PЈ chelates cis-[PtCl2{(PhO)2-
The 31P-{1H} NMR spectra of 10 and 11 show singlets at
[δ(P) 100.4 and 132.2 respectively] with J{195Pt–31P} of 4055 Hz
for 10 in agreement with values previously reported for Pt()
complexes containing the phosphorus, of a P–N ligand, trans to
a chloride23—due to the lack of a highly electronegative oxygen
next to the phosphorus atom, this value is significantly smaller
(3)
1
than the J{195Pt–31P} value in 8. The FABϩ mass spectrum of
each compound displays the parent-ion peak and a peak corre-
sponding to the loss of a chloride ion and the IR spectra show
bands characteristic of ν(PN) stretches (997 cmϪ1 for 10 and 11)
indicating an increase in the bond order. The IR spectra of 10
and 11 also show two distinct ν(MCl) vibrations.
The reaction of Ph2PN(Et)N(Et)PPh2 with equimolar quan-
tities of [PtCl(Me)(cod)] in dichloromethane proceeds accord-
ing to eqn. (5) to give cis-[PtMe(Cl){Ph2PN(Et)N(Et)PPh2}] 12.
PN(Et)N(Et)P(OPh)2}] 8 and cis-[PdCl2{(PhO)2PN(Et)N(Et)-
P(OPh)2}] 9 respectively.
The 31P-{1H} NMR spectra of 8 and 9 [δ(P) 92.3 and 116.6
respectively] exhibit an upfield shift of approximately 3 ppm
when compared to the analogous dimethyl complexes cis-
[MCl2{(PhO)2PN(Me)N(Me)P(OPh)2}].19 The IR spectra of 8
and 9 both contain bands corresponding to ν(PN) and ν(PO)
(968 and 1069 cmϪ1 respectively for 8 and 955 and 1070 cmϪ1
respectively for 9) as well as two distinct ν(MCl) vibrations
which are indicative of a cis-MCl2 geometry. FABϩ mass spec-
trometry shows the expected parent-ion peaks and peaks corre-
sponding to the loss of a chloride ion and elemental analysis
is in good agreement with calculated values. The solid state
structure of 8 is shown in Fig. 1 and selected bond lengths and
angles are shown in Table 1. The structure contains two crystal-
lographically independent molecules although the two mole-
cules are structurally similar. The five-membered chelate rings
result in P–Pd–P angles of less than 90Њ. Both molecules are
almost perfectly planar about the palladium [mean deviation
(5)
The 31P-{1H} NMR spectrum of 12 is an AX type spectrum
due to the chemical inequivalence of the phosphorus centres,
the phosphorus atom trans to the chloride ligand is assigned to
1
the peak at δ(P) 96.8 due to the larger J(195Pt–31P) coupling
associated with it (4577 Hz) and the phosphorus trans to the
methyl group is assigned to the peak at δ(P) 114.2 which has a
smaller 1J(195Pt–31P) coupling of 2016 Hz.
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Table 1 Selected bond lengths (Å) and angles (Њ) for 8, 9, 14 and 15
8
9a
14
15
M(1)–Cl(1)
M(1)–Cl(2)
M(1)–P(1)
M(1)–P(2)
P(1)–N(1)
P(2)–N(2)
N(1)–N(2)
2.344(2)
2.345(2)
2.182(2)
2.177(2)
1.645(5)
1.680(6)
1.440(7)
2.343(2) [2.342(2)]
2.341(2) [2.352(14)]
2.199(2) [2.207(2)]
2.193(2) [2.194(2)]
1.654(4) [1.662(4)]
1.684(4) [1.663(4)]
1.434(5) [1.432(5)]
2.396(3)
—
2.221(4)
—
1.758(13)
—
1.37(2)
2.393(6)
2.398(6)
2.210(7)
2.207(7)
1.70(2)
1.67(2)
1.44(3)
Cl(1)–M(1)–Cl(2)
P(1)–M(1)–P(2)
M(1)–P(1)–N(1)
M(1)–P(2)–N(2)
P(1)–N(1)–N(2)
P(2)–N(2)–N(1)
91.55(6)
82.55(6)
108.2(2)
110.6(2)
119.6(4)
105.9(4)
93.20(6) [94.17(5)]
82.24(6) [81.46(5)]
107.9(2) [108.3(2)]
110.8(2) [110.0(2)]
119.5(3) [119.4(3)]
105.7(3) [109.0(3)]
91.1(2)
84.9(2)
108.0(4)
—
114.2(4)
—
91.0(2)
85.1(2)
107.9(8)
108.2(8)
114.0(20)
115.0(20)
a The values in square brackets are for the second crystallographically independent molecule.
(PhCH2)2PN(Et)N(Et)P(CH2Ph)2 4 reacts with [PtCl2(cod)]
to give the five-membered metallacycle cis-[PtCl2{(PhCH2)2-
PN(Et)N(Et)P(CH2Ph)2}] 13 as a colourless solid in 84% yield.
The 31P-{1H} NMR spectrum shows a single resonance at δ(P)
108.3 with satellites [1J(195Pt–31P) 4033 Hz]. This represents a
downfield shift of 44 ppm from the value recorded for the free
ligand, which is comparable to the difference in shift observed
between 3 and 10.
Pringle and co-workers have recently reported24 on the use of
P–X–P ligands as catalysts for polyketone synthesis. They noted
some interesting effects on reaction rate as a consequence of
ortho substitution of the phenyl rings, with alkyl or OMe sub-
stituents being beneficial. The X-ray structures of 8, 9, 14 and
15 (Table 1, Figs. 1–5) enable some comparisons to be made in
The ligands containing ortho substituted phenyl groups,
(o-C6H4OCH3)2PN(Et)N(Et)P(o-C6H4OCH3)2 5, (o-C6H4O-
CH3)2PN(Me)N(Me)P(o-C6H4OCH3)2 6, and (o-C6H4CH3)2-
PN(Me)N(Me)P(o-C6H4CH3)2 7, also react successfully with
equimolar quantities of [PtCl2(cod)] to yield P,PЈ chelates
14–16.
The 31P-{1H} NMR spectra of all three products show sing-
lets, at δ(P) 90.2, 88.5 and 110.3 respectively, representing
downfield shifts of 45–65 ppm upon complexation. All show
satellites from coupling to 195Pt [1J(195Pt–31P) 4535 for 14, 4438
for 15 and 4289 Hz for 16] consistent with the values observed
for 8, 10, and 13, their relative magnitudes reflecting the nature
of the substituents present, both in the ortho position in the ring
and on the phosphorus atoms.
6 and 7 also react with the dimeric palladium species
[{Pd(C8H12OCH3)(µ-Cl)}2] and NH4PF6 to yield the cis-P,PЈ
chelates
[Pd(C8H12OCH3){(o-C6H4OCH3)2PN(Me)N(Me)P-
(o-C6H4OCH3)2}]PF6 17, and [Pd(C8H12OCH3){(o-C6H4CH3)2-
PN(Me)N(Me)P(o-C6H4CH3)2}]PF6 18 [eqn. (6)] in good yields
(65 and 70% respectively).
Fig. 2 The solid state structure of one of the independent molecules in
cis-[PdCl2{(PhO)2PN(Et)N(Et)P(OPh)2}] 9.
(6)
The 31P-{1H} NMR spectrum of each product shows an AX
type pattern due to the phosphorus centres being chemically
inequivalent, the FABϩ mass spectra of the complexes corre-
spond to the expected parent-cation. The IR spectra of both
complexes show bands assigned to ν(PN) (950 for 17 and
948 cmϪ1 for 18) and elemental analyses are in good agreement
with calculated values.
Fig. 3 The solid state structure of 14.
the hydrazide case. All four structures reveal the expected
square planar geometry at the metal centre with slightly
puckered five-membered MP2N2 rings. Furthermore the influ-
ence of the electron withdrawing OPh group (in comparison to
J. Chem. Soc., Dalton Trans., 2002, 513–519
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(neat, cmϪ1): 2978s, 2935s, 2555s, 2260s, 1451vs, 1379vs, 1355s,
1187vs, 1148vs, 1074vs, 1016vs, 952vs, 858w, 818w, 782w,
761w, 729vs, 612w, 507vs, 436vs, 404vs and 225w. FAB mass
spectrum: m/z 289, [Mϩ].
(PhO)2PN(Et)N(Et)P(OPh)2 2. A solution of phenol (1.30 g,
13.8 mmol) and triethylamine (1.39 g, 1.9 cm3, 13.8 mmol) in
hexane (20 cm3) was added dropwise over a period of 30 min to
a solution of Cl2PN(Et)N(Et)PCl2 (1.00 g, 3.4 mmol) in hexane
(20.0 cm3) at room temperature. The reaction mixture was
stirred for 12 h during which time triethylamine hydrochloride
separated from the colourless solution. This precipitate was
removed by suction filtration and the filtrate evaporated to dry-
ness in vacuo to give a viscous, colourless oil. Yield: 1.45 g, 81%.
Microanalysis: Found (Calc. for C28H30N2O2P2) C, 70.0 (69.6);
H, 5.5 (5.8); N, 5.4 (5.2)%. 31P-{1H} NMR (CDCl3): δ(P) 139.0.
IR (neat, cmϪ1): 2978vs, 2940s, 2350s, 1589s, 1444s, 1372vs,
1349s, 1170vs, 1111s, 1030s, 1009s, 930vs, 818w, 773w, 758m,
608w, 515s, 446m, 395s and 217w. FAB mass spectrum: m/z 520,
[M]ϩ.
Fig. 4 The solid state structure of 15.
Ph2PN(Et)N(Et)PPh2 3. A solution of 1 (1.00 g, 3.4 mmol) in
diethyl ether (20.0 cm3) was added dropwise over a period of
30 min to a stirred solution of 1 M PhMgBr in diethyl ether
(2.50 g, 14.0 cm3, 13.6 mmol) at 0 ЊC and the reaction mixture
stirred for 18 h. Deionized water (20.0 cm3) was added slowly
over 10 min and stirring continued for a further 1 h, after which
the reaction mixture was transferred to a separatory funnel and
the layers separated. The ether layer was dried over MgSO4
and the drying agent then removed by suction filtration. The
filtrate was evaporated to dryness in vacuo to give a white solid
product. Yield: 1.1 g, 70%. Microanalysis: Found (Calc. for
C28H30N2P2) C, 73.9 (73.7); H, 6.5 (6.6); N, 5.9 (6.1)%. 31P-{1H}
NMR (CDCl3): δ(P)64.2. IR (KBr disc, cmϪ1): 2973w, 1651s,
1484w, 1434vs, 1362s, 1320w, 1172vs, 1124s, 1057s, 1024s, 970s,
826s, 759s, 698s, 608w, 575s, 528w, 483w, 333s, 240vs and 230vs.
FAB mass spectrum: m/z 456, [M]ϩ.
Fig. 5 Space filling representation of 15 illustrating the steric shielding
of the metal centre.
(PhCH2)2PN(Et)N(Et)P(CH2Ph)2 4. A solution of 1 (1.00 g,
3.4 mmol) in diethyl ether (20.0 cm3) was added dropwise over a
period of 30 min to a stirred solution of 2 M PhCH2MgCl in
diethyl ether (2.10 g, 6.8 cm3, 13.7 mmol) at 0 ЊC and the reac-
tion mixture stirred for 12 h. Deoinized water (20.0 cm3) was
added slowly over 10 min and stirring continued for a further
1 h, after which the reaction mixture was transferred to a separ-
atory funnel and the layers separated. The ether layer was dried
over MgSO4 and the drying agent then removed by suction
filtration. The filtrate was evaporated to dryness in vacuo to give
a pale yellow, solid product. Yield: 1.3 g, 74%. Microanalysis:
Found (Calc. for C32H38N2P2) C, 74.3 (74.9); H, 7.4 (7.5); N, 5.2
(5.5)%. 31P-{1H} NMR (CDCl3): δ(P) 64.8. IR (KBr disc, cmϪ1):
3025w, 1600s, 1493vs, 1451vs, 1376s, 1210s, 1092s, 1062s, 1028s,
962s, 933s, 906s, 850vs, 823s, 764s, 697s, 585s, 569w, 497s, 478s,
and 230vs. FAB mass spectrum: m/z 512, [M]ϩ.
the o-MeOC6H4 group) is noticeable in the shortening of the
M–P bonds in the OPh containing complexes (Table 1). The
most interesting feature is that in 14 and 15 two of the OMe
groups arrange themselves in close to pseudo-octahedral geom-
etries. [14 Pt ؒ ؒ ؒ O(2) 3.47, O ؒ ؒ ؒ Pt ؒ ؒ ؒ O angle 133Њ; 15
Pt ؒ ؒ ؒ O(9) 3.37 Å, Pt ؒ ؒ ؒ O(23) 3.40 Å, O ؒ ؒ ؒ Pt ؒ ؒ ؒ O 129Њ]
which results in significant congestion above and below the
coordination plane and this may limit the mechanistic pathways
available during the catalytic process.
Experimental
General experimental conditions and instrumentation are as
described previously.25 1,2-Diethylhydrazine dihydrochloride
was crushed using
a pestle and mortar prior to use.
[{Pd(C8H12OCH3)(µ-Cl)}2] was prepared using the literature
procedure.26 Phenol, phosphorus trichloride, PhMgBr,
PhCH2MgCl and o-CH3C6H4MgCl were used without further
purification.
(o-C6H4OCH3)2PN(Et)N(Et)P(o-C6H4OCH3)2 5. A solution
of o-bromoanisole (4.90 g, 3.3 cm3, 26.5 mmol) in diethyl ether
(80.0 cm3) was added dropwise to a slurry of magnesium turn-
ings (1.43 g, 59.0 mmol) and iodine (1 crystal) in diethyl ether
(20.0 cm3) and the reaction mixture stirred for 2.5 h. 60.0 cm3 of
the reaction solution was transferred to a round bottomed flask
and a solution of Cl2PN(Et)N(Et)PCl2 (1.00 g, 3.4 mmol) in
diethyl ether (25.0 cm3) added dropwise over a period of 30
min. After stirring for 24 h, deionized water (25.0 cm3) was
added slowly over 10 min and stirring continued for a further
1 h, after which the reaction mixture was transferred to a separ-
atory funnel and the layers separated. The ether layer was dried
over MgSO4 and the drying agent then removed by suction
filtration. The filtrate was evaporated to dryness in vacuo to give
a colourless oil. The product was washed with light petroleum
Syntheses
Cl2PN(Et)N(Et)PCl2 1. Phosphorus trichloride (10.00 g,
72.7 mmol) was added to a finely crushed sample of 1,2-
diethylhydrazine dihydrochloride (1.00 g, 6.2 mmol) at room
temperature under an atmosphere of nitrogen. The reaction
mixture was heated under reflux for 96 h. The excess phos-
phorus trichloride was removed in vacuo to leave a viscous
orange oil. Distillation of the resulting oil in vacuo left com-
pound 1 as a viscous, colourless oil. Yield: 1.3 g, 72%. Micro-
analysis: Found (Calc. for C4H10Cl4N2P2) C, 17.0 (16.6); H, 3.5
(3.9); N, 9.7 (9.8)%. 31P-{1H} NMR (CDCl3): δ(P) 156.3. IR
516
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(bp 60–80 ЊC) to give a solid product. Yield: 1.31 g, 67%.
Microanalysis: Found (Calc. for C32H38N2O4P2) C, 66.1 (66.6);
H, 6.3 (6.6); N, 4.4 (4.8)%. 31P-{1H} NMR (CDCl3): δ(P) 40.5.
IR (KBr disc, cmϪ1): 3053m, 2941m, 2834m, 1655w, 1571s,
1472s, 1427vs, 1374w, 1270s, 1242vs, 1182m, 1160m, 1128m,
1099w, 1067w, 1027s, 933s, 793m, 757vs, 729w, 708w, 503w,
480w, 431w, 237vs and 218s. FAB mass spectrum: m/z 576,
[M]ϩ.
methane (10.0 cm3) was added dropwise to a solution of
[PdCl2(cod)] (0.100 g, 0.35 mmol) in dichloromethane (5.0 cm3)
and the yellow solution stirred for ca. 2 h. The solution was
concentrated under reduced pressure to ca. 1.0 cm3 and diethyl
ether (20.0 cm3) added. The yellow product was collected by
suction filtration. Yield: 0.123 g, 50%. Microanalysis: Found
(Calc. for C28H30Cl2N2O4P2Pd) C, 48.0 (48.2); H, 4.4 (4.3); N,
4.0 (4.0)%. 31P-{1H} NMR (CDCl3): δ(P) 116.6. IR (KBr disc,
cmϪ1): 2975s, 1585vs, 1484vs, 1455vs, 1377s, 1348w, 1177vs,
1119vs, 1070s, 1024s, 955vs, 822s, 763vs, 682s, 654s, 614w, 575s,
518w, 496w, 329s, 296s, 237vs and 225vs. FAB mass spectrum:
m/z 698, [M]ϩ.
(o-C6H4OCH3)2PN(Me)N(Me)P(o-C6H4OCH3)2 6. A sol-
ution of o-bromoanisole (4.90 g, 3.3 cm3, 26.5 mmol) in diethyl
ether (80.0 cm3) was added dropwise to a slurry of magnesium
turnings (1.43 g, 59.0 mmol) and iodine (1 crystal) in diethyl
ether (20.0 cm3) and the reaction mixture stirred for 2.5 h. 60.0
cm3 of the reaction solution was transferred to a round bot-
tomed flask and a solution of Cl2PN(Me)N(Me)PCl2 (1.00 g,
3.8 mmol) in diethyl ether (25.0 cm3) added dropwise over a
period of 30 min. reaction. After stirring for 24 h, deionized
water (25.0 cm3) was added slowly over 10 min and stirring
continued for a further 1 h, after which the reaction mixture
was transferred to a separatory funnel and the layers separated.
The ether layer was dried over MgSO4 and the drying agent
then removed by suction filtration. The filtrate was evaporated
to dryness in vacuo to give a colourless oil. The product was
washed with light petroleum (bp 60–80 ЊC) to give a solid
product. Yield: 1.7 g, 81%. Microanalysis: Found (Calc. for
C30H34N2O4P2) C, 65.1 (65.7); H, 5.9 (6.3); N, 4.8 (5.1)%. 31P-
{1H} NMR (CDCl3): δ(P) 42.6. IR (KBr disc, cmϪ1): 3385s,
3059s, 3000s, 2935s, 2834s, 1583vs, 1571vs, 1460vs, 1429vs,
1268s, 1238s, 1159w, 1129s, 1092w, 1066s, 1042s, 969vs, 883w,
858w, 792s, 753vs, 692s, 611s, 574w, 498s, 472s, 428vs and 230vs.
FAB mass spectrum: m/z 549, [M]ϩ.
cis-[PtCl2{Ph2PN(Et)N(Et)PPh2}] 10. To
a solution of
[PtCl2(cod)] (0.040 g, 0.11 mmol) in dichloromethane (5.0 cm3)
was added solid Ph2PN(Et)N(Et)PPh2 (0.048 g, 0.11 mmol) and
the colourless solution stirred for ca. 2 h. The solution was
concentrated under reduced pressure to ca. 1.0 cm3 and diethyl
ether (10.0 cm3) added. The white product was collected by
suction filtration. Yield: 0.060 g, 78%. Microanalysis: Found
(Calc. for C28H30Cl2N2P2Pt) C, 47.7 (47.4); H, 4.4 (4.1); N,
1
3.4 (3.8)%. 31P-{1H} NMR (CDCl3): δ(P) 100.4, J(195Pt–31P)
4055 Hz. IR (KBr disc, cmϪ1): 3053s, 2972s, 1572vs, 1480vs,
1436vs, 1380s, 1311w, 1182vs, 1104vs, 1027w, 997s, 921w, 872w,
749vs, 720vs, 692s, 656s, 630w, 578s, 556w, 527s, 507vs, 493w,
471w, 314s, 233vs and 225vs. FAB mass spectrum: m/z 722,
[M]ϩ.
cis-[PdCl2{Ph2PN(Et)N(Et)PPh2}] 11. To a solution of [Pd-
Cl2(cod)] (0.030 g, 0.11 mmol) in dichloromethane (15.0 cm3)
was added solid Ph2PN(Et)N(Et)PPh2 (0.048 g, 0.11 mmol) and
the yellow solution stirred for ca. 2 h. The solution was concen-
trated under reduced pressure to ca. 1.0 cm3 and diethyl ether
(20.0 cm3) added. The yellow product was collected by suction
filtration. Yield: 0.052 g, 78%. Microanalysis: Found (Calc. for
C28H30Cl2N2P2Pd) C, 52.8 (53.1); H, 4.6 (4.8); N, 4.2 (4.4)%.
31P-{1H} NMR (CDCl3): δ(P) 132.2. IR (KBr disc, cmϪ1):
3053w, 2972s, 1618w, 1585w, 1479s, 1436vs, 1380s, 1312w,
1183w, 1118vs, 1101vs, 1026w, 997s, 918w, 750vs, 719vs, 691s,
654s, 609w, 574s, 522s, 490w, 292w and 225vs. FAB mass
spectrum: m/z 634, [M]ϩ.
(o-C6H4CH3)2PN(Me)N(Me)P(o-C6H4CH3)2 7. A solution
of Cl2PN(Me)N(Me)PCl2 (1.00 g, 3.8 mmol) in diethyl ether
(25.0 cm3) was added dropwise over a period of 30 min to a
stirred solution of 1 M o-CH3C6H4MgCl in diethyl ether
(2.30 g, 15.2 cm3, 15.2 mmol) at 0 ЊC and the reaction mixture
heated under reflux for 4 h. Deionized water (25.0 cm3) was
added slowly over 10 min and stirring continued for a further
1 h, after which the reaction mixture was transferred to a separ-
atory funnel and the layers separated. The ether layer was dried
over MgSO4 and the drying agent then removed by suction
filtration. The filtrate was evaporated to dryness in vacuo to give
a yellow oil. The product was washed with light petroleum
(bp 60–80 ЊC) to give a pale yellow solid. Yield: 1.2 g, 65%.
Microanalysis: Found (Calc. for C30H34N2P2) C, 74.7 (74.4);
H, 6.8 (7.1); N, 5.2 (5.8)%. 31P-{1H} NMR (CDCl3): δ(P) 47.2.
IR (KBr disc, cmϪ1): 3396w, 1815w, 1560s, 1520vs, 1439vs,
1377s, 1268w, 1198w, 1156s, 1130s, 1066s, 1030s, 956s, 897s,
845vs, 800s, 751s, 731vs, 718s, 607s, 562w, 487s, 455s, 396w,
292w and 230vs. FAB mass spectrum: m/z 485, [M]ϩ.
cis-[PtMe(Cl){Ph2PN(Et)N(Et)PPh2}] 12. To a solution of
[PtMe(Cl)(cod)] (0.038 g, 0.11 mmol) in dichloromethane
(10.0 cm3) was added solid Ph2PN(Et)N(Et)PPh2 (0.048 g,
0.11 mmol) and the colourless solution stirred for ca. 2 h. The
solution was concentrated under reduced pressure to ca. 1.0 cm3
and diethyl ether (20.0 cm3) added. The white product was col-
lected by suction filtration. Yield: 0.058 g, 79%. Microanalysis:
Found (Calc. for C29H33ClN2P2Pt) C, 49.5 (49.6); H, 4.6 (4.7);
N, 3.8 (3.9)%. 31P-{1H} NMR (CDCl3): δ(PA trans to CH3)
1
1
114.2, J(195Pt–31PA) 2016 Hz, δ(PB trans to Cl) 96.8, J(195Pt–
31PB) 4577 Hz. IR (KBr disc, cmϪ1): 3054s, 2970s, 2874s, 1671w,
1479s, 1436vs, 1377s, 1312w, 1180s, 1122vs, 1103vs, 997w,
750vs, 717vs, 693vs, 652s, 580s, 554s, 524vs, 492s, 301w, 242s
and 210vs. FAB mass spectrum: m/z 702, [M]ϩ.
cis-[PtCl2{(PhO)2PN(Et)N(Et)P(OPh)2}] 8. A solution of
(PhO)2PN(Et) N(Et)P(OPh)2 (0.175 g, 0.34 mmol) in dichloro-
methane (10.0 cm3) was added dropwise to a solution of
[PtCl2(cod)] (0.130 g, 0.34 mmol) in dichloromethane (5.0 cm3)
and the colourless solution stirred for ca. 2 h. The solution was
concentrated under reduced pressure to ca. 1.0 cm3 and diethyl
ether (20.0 cm3) added. The white product was collected by
suction filtration. Yield: 0.178 g, 65%. Microanalysis: Found
(Calc. for C28H30Cl2N2O4P2Pt) C, 42.4 (42.7); H, 3.9 (3.8);
cis-[PtCl2{(PhCH2)2PN(Et)N(Et)P(CH2Ph)2}] 13. To a sol-
ution of [PtCl2(cod)] (0.050 g, 0.13 mmol) in dichloromethane
(15.0 cm3) was added solid (PhCH2)2PN(Et)N(Et)P(CH2Ph)2
(0.068 g, 0.13 mmol) and the colourless solution stirred for ca.
2 h. The solution was concentrated under reduced pressure
to ca. 2.0 cm3 and diethyl ether (20.0 cm3) added. The white
product was collected by suction filtration. Yield: 0.087 g, 84%.
Microanalysis: Found (Calc. for C32H38Cl2N2P2Pt) C, 48.8
(49.4); H, 4.7 (4.9); N, 3.1 (3.6)%. 31P-{1H} NMR (CDCl3): δ(P)
108.3, 1J(195Pt–31P) 4033 Hz, 2J(31PA–31PB) 17 Hz. IR (KBr disc,
cmϪ1): 3026s, 2979s, 2926s, 1601s, 1495vs, 1452vs, 1386s, 1357w,
1260s, 1172vs, 1124s, 1073s, 988w, 917w, 857s, 838s, 808s, 790s,
1
N, 3.4 (3.6)%. 31P-{1H} NMR (CDCl3): δ(P) 92.3, J(195Pt–31P)
5503 Hz. IR (KBr disc, cmϪ1): 2991s, 1585vs, 1484vs, 1455vs,
1385s, 1348s, 1186vs, 1113vs, 1069vs, 1023s, 968vs, 822s, 763vs,
688s, 652s, 614w, 586s, 535w, 439w, 325s, 299m, 236vs and
227vs. FAB mass spectrum: m/z 786, [M]ϩ.
cis-[PdCl2{(PhO)2PN(Et)N(Et)P(OPh)2}] 9. A solution of
(PhO)2PN(Et)N(Et)P(OPh)2 (0.182 g, 0.35 mmol) in dichloro-
J. Chem. Soc., Dalton Trans., 2002, 513–519
517

View Article Online
Table 2 Details of X-ray data collection and refinement
Compound
8
9
14
15
Empirical formula
Formula weight
C28H30Cl2N2O4P2Pt
786.5
C28H30Cl2N2O4P2Pd
697.8
C33.5H43Cl5N2O5P2Pt
988.0
C30.5H35Cl3N2O5P2Pt
857.0
Crystal system
T /K
Space group
Orthorhombic
293(2)
Pbca
Monoclinic
293(2)
P21n
Monoclinic
293(2)
C2/c
Triclinic
298(2)
¯
P1
a/Å
b/Å
c/Å
α/Њ
8.7379(3)
17.2627(5)
40.8907(11)
22.2887(4)
8.8062(2)
32.0433(5)
24.3478(7)
14.2665(3)
14.7842(4)
10.2861(2)
11.9149(1)
15.9825(2)
95.546(1)
99.112(1)
106.871(1)
1824
2
1.56
4.19
5158
β/Њ
105.61(1)
111.458(1)
γ/Њ
V/Å3
6168
8
1.69
4.86
4399
6057
8
1.53
0.93
8637
4779
4
1.37
3.32
5501
Z
Dc/Mg mϪ3
Absorption coefficient/mmϪ1
Observed independent reflections
[I > 2.0σ(I )]
Final R, Rw
0.0339, 0.0631
0.0449, 0.0728
0.0875, 0.1953
0.0774, 0.2781
773s, 755vs, 695vs, 610w, 582s, 569w, 535w, 472w, 317s, 235s
[Pd(C8H12OCH3){(o-C6H4OCH3)2PN(Me)N(Me)P(o-C6H4-
OCH3)2}]PF6 17. To a stirred solution of [{Pd(C8H12OCH3)-
(µ-Cl)}2] (0.050 g, 0.09 mmol) in dichloromethane (10.0 cm3)
was added solid NH4PF6 (0.030 g, 0.18 mmol) and the reaction
mixture stirred for a further 30 min. A solution of (C6H4-o-
OCH3)2PN(Me)N(Me)P(C6H4-o-OCH3)2 (0.100 g, 0.18 mmol)
in dichloromethane (10.0 cm3) was then added dropwise to the
reaction mixture over a period of 10 min and the resulting dark
brown solution stirred for 2 h. The solution was concentrated
under reduced pressure to ca. 5.0 cm3 and diethyl ether
(25.0 cm3) added. The light brown product was collected by
suction filtration. Yield: 0.109 g, 65%. Microanalysis: Found
(Calc. for C39H49F6N2OP3Pd) C, 53.8 (53.5); H, 5.6 (5.6); N, 3.1
(3.2)%. 31P-{1H} NMR (CDCl3): δ(P) 104.8 and 92.1, 2J-
(31P–31P) 66 Hz. IR (KBr disc, cmϪ1): 2933w, 1586m, 1574m,
1515m, 1474s, 1431s, 1275s, 1245s, 1164m, 1135m, 1075w,
1043w, 1018m, 950m, 839s, 797m, 756m, 737w, 657w, 616m,
580w, 557m, 523w, 501w, 436w and 358w. FAB mass spectrum:
m/z 794, [M Ϫ PF6]ϩ.
and 229vs. FAB mass spectrum: m/z 778, [M]ϩ.
cis-[PtCl2{(o-C6H4OCH3)2PN(Et)N(Et)P(o-C6H4OCH3)2}]
14. To a solution of [PtCl2(cod)] (0.100 g, 0.26 mmol) in di-
chloromethane (5.0 cm3) was added solid (C6H4-o-OCH3)2-
PN(Et)N(Et)P(C6H4-o-OCH3)2 (0.154 g, 0.26 mmol) and the
colourless solution stirred for ca. 2 h. The solution was concen-
trated under reduced pressure to ca. 2.0 cm3 and diethyl ether
(20.0 cm3) added. The white product was collected by suction
filtration.Yield: 0.107 g, 70%. Microanalysis: Found (Calc. for
C32H30Cl2N2O4P2Pt) C, 45.1 (45.6); H, 4.4 (4.5); N, 2.8 (3.3)%.
31P-{1H} NMR (CDCl3): δ(P) 90.2, 1J(195Pt–31P) 4535 Hz.
IR (KBr disc, cmϪ1): 3065w, 2937w, 2864w, 1588s, 1573s,
1477vs, 1463s, 1430vs, 1375w, 1282s, 1253s, 1182m, 1165m,
1109m, 1075m, 1045m, 1019s, 943w, 801s, 757s, 692m, 633m,
581m, 557m, 506m, 446w, 337w, 303w, 280w and 229s. FAB
mass spectrum: m/z 842, [M]ϩ.
cis-[PtCl2{(o-C6H4OCH3)2PN(Me)N(Me)P(o-C6H4OCH3)2}]
15. To a solution of [PtCl2(cod)] (0.075 g, 0.20 mmol) in
dichloromethane (5.0 cm3) was added solid (C6H4-o-OCH3)2-
PN(Me)N(Me)P(C6H4-o-OCH3)2 (0.110 g, 0.20 mmol) and the
colourless solution stirred for ca. 2 h. The solution was concen-
trated under reduced pressure to ca. 2.0 cm3 and diethyl ether
(20.0 cm3) added. The white product was collected by suction
filtration. Yield: 0.101 g, 57%. Microanalysis: Found (Calc. for
C30H34Cl2N2O4P2Pt) C, 48.1 (48.8); H, 3.4 (3.9); N, 2.8 (3.2)%.
[Pd(C8H12OCH3){(o-C6H4CH3)2PN(Me)N(Me)P(o-C6H4-
CH3)2}]PF6 18. To a stirred solution of [{Pd(C8H12OCH3)-
(µ-Cl)}2] (0.130 g, 0.23 mmol) in dichloromethane (10.0 cm3)
was added solid NH4PF6 (0.075 g, 0.46 mmol) and the reaction
mixture stirred for a further 30 min. A solution of (C6H4-o-
CH3)2PN(Me)N(Me)P(C6H4-o-CH3)2 (0.222 g, 0.46 mmol) in
dichloromethane (10.0 cm3) was then added dropwise to the
reaction mixture over a period of 10 min and the resulting dark
brown solution stirred for 2 h. The solution was concentrated
under reduced pressure to ca. 5.0 cm3 and diethyl ether
(25.0 cm3) added. The light brown product was collected by
suction filtration. Yield: 0.280 g, 70%. Microanalysis: Found
(Calc. for C39H49F6N2OP3Pd) C, 53.0 (53.5); H, 5.6 (5.6); N, 3.1
(3.2)%. 31P-{1H} NMR (CDCl3): δ 113.4 and 105.2, 2J(31P–31P)
66 Hz. IR (KBr disc, cmϪ1): 2924vs, 1624w, 1588s, 1523vs,
1448vs, 1381w, 1278s, 1186s, 1132s, 1081s, 1023s, 948w,
839vs, 806s, 757vs, 719s, 682w, 611w, 556vs, 538w, 508w,
488s, 469s, 280w, 242s and 229vs. FAB mass spectrum: m/z 730,
[M Ϫ PF6]ϩ.
1
31P-{1H} NMR (CDCl3): δ(P) 88.5, J(195Pt–31P) 4438 Hz. IR
(KBr disc, cmϪ1): 3386s, 3067s, 2932s, 2833s, 1637w, 1587vs,
1571s, 1474vs, 1455vs, 1428vs, 1276s, 1251s, 1164w, 1136w,
1072w, 1016s, 965w, 800s, 762vs, 694w, 646s, 581s, 558s, 526w,
509w, 484w, 445s, 365w, 276w, 230s and 215vs. FAB mass
spectrum: m/z 814, [M]ϩ.
cis-[PtCl2{(o-C6H4CH3)2PN(Me)N(Me)P(o-C6H4CH3)2}] 16.
To a solution of [PtCl2(cod)] (0.070 g, 0.19 mmol) in
dichloromethane (5.0 cm3) was added solid (C6H4-o-CH3)2-
PN(Me)N(Me)P(C6H4-o-CH3)2 (0.090 g, 0.19 mmol) and the
colourless solution stirred for ca. 1 h. The solution was concen-
trated under reduced pressure to ca. 2.0 cm3 and diethyl ether
(15.0 cm3) added. The white product was collected by suction
filtration. Yield: 0.092 g, 69%. Microanalysis: Found (Calc.
for C30H34Cl2N2P2Pt) C, 47.5 (48.0); H, 4.3 (4.6); N, 3.5 (3.7)%.
Crystallography
Was performed using a Bruker SMART diffractometer; full
hemisphere of data with 0.3Њ ‘slices’, room temperature,
Mo-Kα radiation and empirical absorption corrections. All
of the other non-hydrogen atoms were refined anisotropically
with the hydrogen atoms being refined in idealised geometries.
In 14 the hydrogen atoms of the solvate water were not included
in the refinement. All calculations employed the SHELXTL
program system.27 Refinement and data collection details are
summarised in Table 2.
1
31P-{1H} NMR (CDCl3): δ(P) 110.3, J(195Pt–31P) 4289 Hz. IR
(KBr disc, cmϪ1): 2894s, 1654w, 1591s, 1561s, 1447vs, 1379s,
1283s, 1203w, 1162w, 1133s, 1084s, 946w, 808s, 762vs, 723s,
684w, 576s, 554w, 531w, 515w, 494s, 455s, 420s, 303w, 286w,
235s and 230vs. FAB mass spectrum: m/z 714, [M Ϫ Cl]ϩ.
518
J. Chem. Soc., Dalton Trans., 2002, 513–519

View Article Online
10 J. Ellermann, F. A. Knoch and K. J. Meier, Z. Naturforsch., Teil B,
CCDC reference numbers 168562–168564 and 168964.
See http://www.rsc.org/suppdata/dt/b1/b107072j/ for crystal-
lographic data in CIF or other electronic format.
1990, 45, 1657.
11 D. S. Dumond and M. G. Richardson, J. Am. Chem. Soc., 1988, 100,
7547.
12 A. Tarassoli, H.-J. Chen, M. L. Thompson, U. S. Ullured, R. C.
Haltiwanger and A. D. Norman, Inorg. Chem., 1986, 25, 4152.
13 E. O. Fischer, W. Kellar, B. Z. Gasser and U. Schubert,
J. Organomet. Chem., 1980, 199, C24.
14 J. T. Mague and M. P. Johnson, Organometallics, 1990, 9, 1254.
15 J. T. Mague and Z. Lin, Organometallics, 1992, 11, 4139.
16 R. P. Kamalesh Babu, S. S. Krishnamurthy and M. Nethali,
J. Organomet. Chem., 1993, 454, 157.
Acknowledgements
We are grateful to BP for support and to the Joint Research
Equipment Initiative for an equipment grant.
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J. Chem. Soc., Dalton Trans., 2002, 513–519
519