Synthesis of 1,3-azaphosphol-2-ones. Crystal and molecular structures of [SP-4-2]-dichlorobis(3-phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-one-P) palladium(ii) and its chloro(methyl)platinum(ii) analogue

Article abstract of DOI:10.1039/b916913j

Reaction of secondary phosphine (±)-(2-aminophenyl)phenylphosphine, (±)-app, with PCl₅ in toluene gives the hydrochloride salt of the expected chlorophosphine (±)-(2-aminophenyl)chlorophenylphosphine, (±)-acpp.HCl, however, this is not the case with triphosgene. Rather the first example of a 1,3-azaphosphol-2-one is isolated, viz. (±)-3-phenyl- 1,3-dihydrobenzo[1,3]azaphosphol-2-one, (±)-pbap. The hydrochloride salt (±)-acpp.HCl readily reacts with excess vinyl-, 2-methylphenyl- or 2-methoxyphenyl magnesium bromide to give the corresponding tertiary phosphines (±)-(2-H₂NC₆H₄)PPhR (where R = CHCH ₂, 2-C₆H₄Me or 2-C₆H ₄OMe). Hydrophosphination of the vinyl substituted tertiary phosphine with (±)-app in the presence of KOBu^t provides a synthetic route to the elusive P₂N₂ quadridentate ligand (R _P*,R_P*)- and (R_P* ,S _P*)-(CH₂)₂ (PPhC₆ H ₄NH₂-2)₂, albeit in low yield. The azaphospholone (±)-pbap can be readily deprotonated with KOBu^t in thf and subsequently alkylated with methyl iodide or benzyl bromide to give the analogous N-methyl or N-benzyl derivatives. Alkylation with 1,3-dibromopropane gives the bis(azaphospholone) (R_P*,R _P*)- and (R_P*,S_P*)-1,3-bis[1- {3-phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-one}]propane. The latter and the N-methyl substituted azaphospholone can also be synthesised by the reaction of the corresponding secondary phosphine, viz. (R_P*,R _P*)- and (R_P*,S_P*)-(CH ₂)₃(NHC₆H₄PHPh-2)₂ and (±)-(2-methylaminophenyl)phenylphosphine, with triphosgene. All three azaphospholones react with [PtClMe(1,5-cyclooctadiene)] in thf to give complexes of the type cis-[PtClMeL₂] in which ligand L is coordinated via the P atom of the azaphospholones. The ligand (±)-pbap has also been complexed to palladium(ii) via the reaction with Li₂[PdCl ₄] in methanol to give cis-[PdCl₂{(±)-pbap} ₂]. The structures of cis-[PtClMe{(±)-pbap}₂] and cis-[PdCl₂{(±)-pbap}₂] have been confirmed by X-ray analysis. The Royal Society of Chemistry 2010.

Full text of DOI:10.1039/b916913j

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www.rsc.org/dalton | Dalton Transactions
Synthesis of 1,3-azaphosphol-2-ones. Crystal and molecular structures
of [SP-4-2]-dichlorobis(3-phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-
one-P)palladium(II) and its chloro(methyl)platinum(II) analogue†
Justine Bennett, Roy J. Doyle, Hwi-Young Lee, Di Lu, Geoffrey Salem,* David J. Speldewinde, Michelle Tifan
and Anthony C. Willis
Received 17th August 2009, Accepted 1st October 2009
First published as an Advance Article on the web 10th November 2009
DOI: 10.1039/b916913j
Reaction of secondary phosphine ( )-(2-aminophenyl)phenylphosphine, ( )-app, with PCl5 in toluene
gives the hydrochloride salt of the expected chlorophosphine ( )-(2-aminophenyl)chlorophenyl-
phosphine, ( )-acpp.HCl, however, this is not the case with triphosgene. Rather the first example
of a 1,3-azaphosphol-2-one is isolated, viz. ( )-3-phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-one,
( )-pbap. The hydrochloride salt ( )-acpp.HCl readily reacts with excess vinyl-, 2-methylphenyl- or
2-methoxyphenyl magnesium bromide to give the corresponding tertiary phosphines
=
( )-(2-H2NC6H4)PPhR (where R = CH CH2, 2-C6H4Me or 2-C6H4OMe). Hydrophosphination of the
vinyl substituted tertiary phosphine with ( )-app in the presence of KOBut provides a synthetic route to
the elusive P2N2 quadridentate ligand (RP*,RP*)- and (RP*,SP*)-(CH2)2(PPhC6H4NH2-2)2, albeit in low
yield. The azaphospholone ( )-pbap can be readily deprotonated with KOBut in thf and subsequently
alkylated with methyl iodide or benzyl bromide to give the analogous N-methyl or N-benzyl
derivatives. Alkylation with 1,3-dibromopropane gives the bis(azaphospholone) (RP*,RP*)- and
(RP*,SP*)-1,3-bis[1-{3-phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-one}]propane. The latter and the
N-methyl substituted azaphospholone can also be synthesised by the reaction of the corresponding
secondary phosphine, viz. (RP*,RP*)- and (RP*,SP*)-(CH2)3(NHC6H4PHPh-2)2 and ( )-(2-
methylaminophenyl)phenylphosphine, with triphosgene. All three azaphospholones react with
[PtClMe(1,5-cyclooctadiene)] in thf to give complexes of the type cis-[PtClMeL2] in which ligand L is
coordinated via the P atom of the azaphospholones. The ligand ( )-pbap has also been complexed to
palladium(II) via the reaction with Li2[PdCl4] in methanol to give cis-[PdCl2{( )-pbap}2]. The
structures of cis-[PtClMe{( )-pbap}2] and cis-[PdCl2{( )-pbap}2] have been confirmed by X-ray
analysis.
equivalents of lithium in thf or sodium in liquid ammonia, to
Introduction
give the secondary phosphine ( )-2-H2NC6H4PHPh, ( )-app, 2,
upon hydrolysis followed by metallation with sodium in thf and
alkylation with, for example, CH3I, Br(CH2)nBr (where n = 3–
6) or CH3C(CH2Br)3 to give ( )-2-H2NC6H4PMePh, (RP*,RP*)-
and (RP*,SP*)-(CH2)n(PPhC6H4NH2-2)2 and (RP*,RP*,RP*)- and
(RP*,RP*,SP*)-CH3C(CH2PPhC6H4NH2-2)3, respectively.4–6 This
approach typically, however, does not allow access to substituted
(2-aminophenyl)phosphines of the type ( )-2-H2NC6H4PPhR
(where R = aryl or vinyl group). A rare exception is the
2-chlorophenyl substituted PN ligand ( )-(2-aminophenyl)(2-
chlorophenyl)methylphosphine.7 In the current work conver-
sion of secondary phosphine ( )-app, 2, to the corresponding
chlorophosphine has been investigated using PCl5 or triphos-
gene. The hydrochloride salt of the expected chlorophosphine
( )-(2-aminophenyl)chlorophenylphosphine, ( )-acpp.HCl, 3, is
isolated using PCl5. Further reaction of 3 with an excess
of the appropriate Grignard reagent does provide a route to
substituted (2-aminophenyl)phosphines of the type ( )-2-H2-
NC6H4PPhR (where R = aryl or vinyl group). No formation
of a chlorophosphine, however, was observed using triphosgene,
rather a stable azaphospholone was isolated, viz. ( )-3-phenyl-1,
Metathesis of chlorophosphines with organometallic reagents has
been, and continues to be, an important preparative route to
unidentate, bidentate and, to a lesser degree, multidentate tertiary
phosphines.1 A common synthetic route to chlorophosphines
involves chlorination of the analogous primary or secondary
phosphine with, for example, C2Cl6, PCl5 or more recently
triphosgene, (Cl3CO)2CO.2,3 The latter is often the reagent of
choice particularly for small scale reactions as the side products
are CO and HCl.
Tertiary phosphine (2-aminophenyl)diphenylphosphine, adpp,
1, is a versatile hybrid ligand that can be used to prepare a range
of related bidentate PN and multidentate P2N2 and very recently
P3N3 ligands via derivatisation of the amino or diphenylphosphino
groups.4 Derivatisation of the latter has typically been achieved
via reductive cleavage of a phenyl group from adpp using three
Research School of Chemistry, College of Physical Sciences, Australian
National University, Canberra, A. C. T. 0200, Australia. E-mail: Geoff.
Salem@anu.edu.au
† CCDC reference numbers 744588 and 744589. For crystallographic data
in CIF or other electronic format see DOI: 10.1039/b916913j
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Scheme 1 Synthesis of azaphospholone 4 and its N-substituted derivatives 9 and 10, tertiary phosphines 5–7 and the quadridentate NP2N ligand 8.
3-dihydrobenzo[1,3]azaphosphol-2-one, ( )-pbap, 4, the first ex-
ample of a 1,3-azaphosphol-2-one. Several examples of azaphos-
pholes and, in particular, benzazaphospholes have been reported
in the literature but there appear to be no examples of the related
benzazaphospholones.8
12% yield (based on the quantity of unreacted secondary
phosphine recovered from the reaction) by heating a thf solution
of 2, 5 and a catalytic amount of KOBut under reflux for 20 days.
The yield of the addition reaction could not be improved by
using higher boiling point solvents such as benzene or toluene
or by attempting a free-radical catalysed reaction using AIBN in
toluene at 110 ◦C.
Results and discussion
Reaction of ( )-app, 2, with PCl5: synthesis of ( )-2-H2NC6H4-
Reaction of ( )-app, 2, with triphosgene: synthesis of
( )-3-phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-one,
( )-pbap, 4, and its N-substituted derivatives
=
PPhR (where R = CH CH2, 2-C6H4Me or 2-C6H4OMe) and
(RP*,RP*)- and (RP*,SP*)-(CH2)2(PPhC6H4NH2-2)2
The reaction of the secondary phosphine ( )-app, 2, with
PCl5 in dry toluene gave a moisture sensitive white solid
that is believed to be the hydrochloride salt of ( )-(2-amino-
phenyl)(chloro)phenylphosphine, ( )-acpp.HCl, 3 (see Scheme 1).
The latter was insoluble in most common solvents and hence
no useful NMR data could be obtained. The assignment was
confirmed by further reaction of 3 with an excess of the
appropriate Grignard reagent in thf to give the bidentate PN
ligands ( )-(2-aminophenyl)phenylvinylphosphine, ( )-apvp, 5,
( )-(2-aminophenyl)(2-methylphenyl)phenylphosphine, ( )-aptp,
6, and ( )-(2-aminophenyl)(2-methoxyphenyl)phenylphosphine,
( )-aapp, 7. Whereas one singlet 31P resonance was observed for
No evidence for the formation of chlorophosphine ( )-acpp
or its hydrochloride salt ( )-acpp.HCl, 3, was observed upon
reaction of secondary phosphine 2 with one-third equivalent of
triphosgene in thf, rather the first example of a 1,3-azaphosphol-
2-one, viz. ( )-3-phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-one,
( )-pbap, 4, was isolated in 80% yield upon crystallisation from
toluene. The amido group of 4 can be readily deprotonated
by reaction with KOBut in thf and subsequently treated with
MeI or BnBr to give the N-substituted derivatives ( )-1-methyl-
3-phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-one, ( )-mpbap, 9,
and ( )-1-benzyl-3-phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-
one, ( )-bpbap, 10, respectively (Scheme 1). The N-methyl sub-
stituted 1,3-azaphosphol-2-one 9 has also been prepared by
the reaction of the N-methyl substituted analogue of 2, viz.
( )-(2-methylaminophenyl)phenylphosphine, ( )-mapp, 11, with
one-third equivalent of triphosgene in thf (Scheme 2). The
N-methyl substituted secondary phosphine 11 was prepared
in two steps from adpp, 1. Reaction of the latter with n-
butyllithium/tmeda in n-hexane followed by the addition of
MeI gave (2-methylaminophenyl)diphenylphosphine, madpp, 12,
which was further reacted with three equivalents of lithium in thf
to give 11 upon hydrolysis.
1
both 6 and 7 in their respective 31P{ H} NMR spectra, two singlets
were found in the analogous spectrum of 5. Molecular models
suggest the existence of two conformers resulting from restricted
rotation of the 2-aminophenyl group with respect to the double
bond may account for the observation of two rather than one 31
P
resonance for ( )-apvp, 5. Selected NMR data is given in Table 1.
Vinylphosphine 5 was seen as a potential precursor to the
elusive quadridentate PN2P ligand (RP*,RP*)- and (RP*,SP*)-
(CH2)n(PPhC6H4NH2-2)2 (where n = 2) which cannot be
synthesised in the same manner as its analogues (where n = 3–6).5
The quadridentate ligand (RP*,RP*)- and (RP*,SP*)-
(CH2)2(PPhC6H4NH2-2)2, C2-NP2N, 8, was isolated in ca.
Reaction of ( )-pbap, 4, with KOBut in thf followed by
the addition of half an equivalent of 1,3-dibromopropane
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1
Table 1 Selected 31P{ H} NMR and 1H NMR dataa
1
31P{ H}
1H
Compound
dP
dNH
d(Other)
4
-30.9 s
9.73 bs
4.20 bs
4.16 bs
4.12 bs
3.94 bs
—
—
4.25 bs
—
—
=
5
- 10.9 s, -11.0 s
-27.1 s
5.59 m, 5.93 m (C CH2)
6
2.40 s (CMe)
7
-31.1 s
3.74 s (OMe)
8
-31.0 s
2.12 m (NCH2)
9
-35.7 s
3.07 s (NMe)
10
11
13
14
-36.3 s
4.89, 4.96 ABq (NCH2Ph)
2.80 s (NMe), 5.09 d (PH)
1.90 m (CCH2), 3.72 m (NCH2)
1.52 m (CCH2), 2.82 m (NCH2)
5.07 d (PH)
-60.7 s
-36.7 s
-60.3 s, -60.5 s
4.06 bs
1
b
31P{ H}
1Hb
Compound
dPc
dPtMe
d(Other)
cis-[PtClMe(4)2]
cis-[PtClMe(9)2]
cis-[PtClMe(10)2]
cis-[PdCl2(4)2]
-5.0 d (4310), 1.3 (1625)
-5.2 d (4357), 0.6 (1621)
-4.7 d (4362), 1.7 (1621)
28.9 s
1.16 bs
0.66 bs
0.33 bs
—
11.16 d, 11.61 d (NH)
2.62 s, 2.91 s (NMe)
3.91, 4.03 ABq (NCH2)
11.16 d (NH)
1
a In CDCl3 unless otherwise stated. b In (CD3)2SO. c JPtP given in Hz in parentheses.
Scheme 2 Alternative synthesis of N-methyl substituted azaphospholone 9.
gave the first example of a bis(1,3-azaphosphol-2-one), viz.
Complexes of the 1,3-azaphosphol-2-ones 4, 9, and 10
(RP*,RP*)- and (RP*,SP*)-1,3-bis[1-{3-phenyl-1,3-dihydrobenzo-
[1,3]azaphosphol-2-one}]propane, (RP*,RP*)- and (RP*,SP*)-
(CH2)3(pbap)2, 13 (Scheme 3). The latter has also been pre-
pared by the reaction of bis(secondary phosphine) (RP*,RP*)-
and (RP*,SP*)-(CH2)3(NHC6H4PHPh-2)2, C3-PN2PH, 14, with
two-third equivalent of triphosgene in thf. The bis(secondary
phosphine) (RP*,RP*)- and (RP*,SP*)-(CH2)3(NHC6H4PHPh-2)2,
14, was synthesised from the linear quadridentate PN2P ligand
(CH2)3(NHC6H4PPh2-2)2 by reaction with six equivalents of
lithium in thf followed by hydrolysis with NH4Cl.
The proposed mechanism for the reaction of triphosgene
with ( )-app, 2, is shown in Fig. 1. Nucleophilic attack of
the phosphino group of 2 on C(2) of triphosgene followed
by loss of HCl and phosgene presumably gives an acyl inter-
mediate Cl3COC(O)P(Ph)C6H4NH2-2 which undergoes further
nucleophilic attack by the amino group at the acyl C atom
with further loss of HCl and phosgene to give azaphospho-
lone ( )-pbap, 4. The two equivalents of phosgene generated
in the reaction further react with 2 in a similar manner, i.e.
via sequential nucleophilic attack by the phosphino and amino
groups on the acyl C atom, to give more HCl and 4. Thus
one equivalent of triphosgene reacts with three equivalents of
2 to produce three equivalents of 4 and six equivalents of
HCl.
The three 1,3-azaphosphol-2-ones have been coordinated to
platinum(II) via the reaction with [PtClMe(1,5-cyclooctadiene)]
in thf to give complexes of the type cis-[PtClMeL2] [where L =
1
( )-pbap, 4, ( )-mpbap, 9, or ( )-bpbap, 10]. The 31P{ H} NMR
spectra of the three complexes in (CD3)2SO each showed a pair
of doublet 31P resonances (2JPP ~ 14 Hz) with associated satellites
due to 195Pt-31P coupling (1JPtP ~ 4350 and 1625 Hz) consistent with
a cis stereochemistry for each of the complexes. A palladium(II)
complex of 4, viz. cis-[PdCl2(4)2], was also prepared via the reaction
of two equivalents of the ligand with a solution of Li2[PdCl4]
in methanol. The structures of the complexes cis-[PtClMe(4)2]
and cis-[PdCl2(4)2] have been confirmed by X-ray analysis. The
molecular structures of the two complexes are depicted in Fig. 2
and 3, and selected bond lengths and angles are given in Table 2.
The structural data clearly shows the presence of two cis disposed
1,3-azaphosphol-2-ones bound to the metal centre as unidentate
ligands through the stereogenic phosphorus donor atoms. The
latter have opposite relative configurations in the two structures
and hence they are both correctly meso complexes. The metal
centres in these two complexes have distorted square-planar coor-
dination geometries. Each of the 1,3-azaphosphol-2-one ligands
has a planar structure with the carbonyl moiety lying in the same
plane as the six carbon atoms of the 1,2-substituted benzene
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Scheme 3 Synthesis of bis(azaphospholone) 13.
˚
hybridised nitrogen atom and the carbonyl moiety, presumably
a key feature in terms of stabilising the 1,3-azaphosphol-2-one
structure.
Table 2 Selected non-hydrogen interatomic distances (A) and interatomic
angles (◦) for cis-[PtClMe(4)2] and cis-[PdCl2(4)2]
cis-[PtClMe(4)2]
cis-[PdCl2(4)2]
Pt–Cl(1)a
2.2873(13)
2.3032(15)
2.2435(9)
2.2345(9)
2.2873(13)
2.3032(15)
1.880(4)
1.915(4)
1.798(4)
1.794(4)
1.811(4)
1.816(4)
1.351(4)
1.413(5)
1.337(5)
1.398(6)
1.219(5)
1.196(5)
90.41(5)
90.41(5)
87.21(5)
87.21(5)
174.08(5)
174.08(5)
170.99(5)
170.99(5)
98.30(3)
84.18(6)
84.18(6)
Pd–Cl(1)
Pd–Cl(2)
Pd–P(1)
Pd–P(2)
2.3516(7)
2.3404(7)
2.2420(7)
2.2282(7)
Conclusion
Pt–Cl(2)a
Pt–P(1)
This work describes a high yielding synthetic route to 1,3-
benzazaphosphol-2-ones under mild conditions via the reaction
of a (2-aminophenyl) substituted secondary phosphine with one-
third equivalent of triphosgene. Derivatisation at the N atom,
by deprotonation and subsequent alkylation, and coordination
as a unidentate ligand via the P centre [to palladium(II) and
platinum(II)] has also been demonstrated for azaphospholone
( )-pbap, 4, in this work. Conversion of (2-aminophenyl) sub-
stituted secondary phosphines to the corresponding chlorophos-
phine can be achieved via reaction with PCl5 and the latter
readily alkylated by metathesis with an appropriate Grignard
reagent. Further work is focusing on the reactivity of the
carbonyl moiety of azaphospholone 4 and the resolution of the
latter.
Pt–P(2)
Pt–C(1)a
Pt–C(2)a
P(1)–C(10)
P(2)–C(30)
P(1)–C(11)
P(2)–C(31)
P(1)–C(20)
P(2)–C(41)
N(1)–C(10)
N(1)–C(12)
N(2)–C(30)
N(2)–C(32)
O(1)–C(10)
O(2)–C(30)
Cl(1)–Pt–P(1)a
C(1)–Pt–P(1)a
Cl(2)–Pt–P(2)a
C(2)–Pt–P(2)a
Cl(2)–Pt–P(1)a
C(2)–Pt–P(1)a
Cl(1)–Pt–P(2)a
C(1)–Pt–P(2)a
P(1)–Pt–P(2)
Cl(1)–Pt–C(2)
Cl(2)–Pt–C(1)
P(1)–C(10)
P(2)–C(30)
P(1)–C(11)
P(2)–C(31)
P(1)–C(21)
P(2)–C(41)
N(1)–C(10)
N(1)–C(12)
N(2)–C(30)
N(2)–C(32)
O(1)–C(10)
O(2)–C(30)
Cl(1)–Pd–P(1)
1.888(3)
1.874(3)
1.783(3)
1.794(3)
1.811(3)
1.810(3)
1.355(3)
1.408(3)
1.358(4)
1.398(5)
1.211(3)
1.216(4)
88.17(2)
Cl(2)–Pd–P(2)
Cl(2)–Pd–P(1)
Cl(1)–Pd–P(2)
84.56(5)
176.91(3)
173.46(3)
Experimental
Procedures and materials
P(1)–Pd–P(2)
Cl(1)–Pd–Cl(2)
96.30(3)
91.22(3)
Reactions involving air-sensitive reagents were performed under
argon using Schlenk techniques. Solvents were dried and purified
by distillation under argon. NMR spectra were obtained using
a Varian Gemini 300 spectrometer operating at 300 MHz (1H),
a There is disorder of the methyl and chloro ligands and hence distances and
angles listed here involving these atoms are presumably for the weighted
average positions.
121.5 MHz (31P{ H}) or 75 MHz (13C{ H}). Chemical shift values
(d) are reported in ppm referenced relative to tetramethylsilane for
1H, CDCl3 (77.0 ppm) or CD2Cl2 (53.8 ppm) as appropriate for
1
1
ring and the nitrogen and phosphorus atoms of the heterocycle.
This arrangement maximises the p interaction between the sp2
1
1
13C{ H} and external 85% aqueous H3PO4 for 31P{ H}. Melting
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Fig. 1 Proposed mechanism for the formation of 4
Fig. 2 Molecular structure of the complex cis-[PtClMe(4)2] (ellipsoids
Fig. 3 Molecular structure of the complex cis-[PdCl2(4)2] (ellipsoids show
show 30% probability levels).
30% probability levels).
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mol) in thf (40 mL) followed by the slow addition of 2-
bromotoluene (5.38 g, 0.0314 mol). The solution was cooled to
0
points were determined using a Leica Galen III melting
point apparatus and microscope fitted with a digital meter.
Elemental analyses were carried out by staff in the micro-
analytical laboratory at the Research School of Chemistry and
mass spectra for compounds with molecular weights over 400
obtained by staff at the Research School of Chemistry. ESI-MS
spectra were recorded on a FISONS VG QUATTRO II mass
spectrometer, operating at a cone voltage between 40 and 70 V,
with positive ion detection. EI MS and HR-EI MS were recorded
on a VG autospec mass spectrometer, operating at 70 eV using
positive ion detection. Mass spectra are recorded in mass/charge
ratios (m/z).
◦C and solid 3 (1.92 g, 0.0081 mol) added in portions. The
reaction mixture was stirred overnight at ambient temperature
and subsequently heated under reflux for 2 h. The reaction
mixture was cooled to 0 ◦C and a saturated aqueous ammonium
chloride solution (30 mL) followed by water (30 mL) were
added and the resulting two phases separated. The aqueous
phase was extracted with dichloromethane (3 ¥ 20 mL) and the
combined organic extracts dried (MgSO4), filtered and the solvent
removed under reduced pressure. The residue was dissolved in
hot methanol (10 mL) to yield a white solid upon cooling. The
crystallisation was completed at -4 ◦C overnight. The crystals
were filtered off, washed with cold methanol (2 mL) and dried
in vacuo (1.40 g, 60%). (Found: C, 76.35; H, 6.31; N, 4.70. Calc.
The compounds (2-aminophenyl)diphenylphosphine, adpp,
1,15 ( )-(2-aminophenyl)phenylphosphine, ( )-app, 2,4 1,3-bis[2-
1
(diphenylphosphinophenyl)amino]propane,
(CH2)3(NHC6H4-
for C19H18PN.0.5H2O: C, 75.98; H, 6.38; N, 4.66%.) H NMR
PPh2-2)2,16 and [SP-4-2]-chloro(cycloocta-1,5-diene)methyl-
platinum(II), [PtClMe(cod)],17 were prepared by literature
procedures.
(CDCl3): d 2.40 (s, 3 H, CMe); 4.16 (bs, 2 H, NH2); 6.68–7.37 (m,
1
13 H, aromatics). 31P{ H} NMR (CDCl3): d -27.1 (s, 1 P). LR-EI
MS: m/z 291 (M)+, 275 (M - CH4)+, 198 (M–C6H5NH2)+. HR-EI
MS: Found for (M)+ 291.1168 (calc. for C19H18NP: 291.1177).
Preparations
( )-(2-Aminophenyl)phenylvinylphosphine, ( )-apvp, 5. Vinyl
bromide (5.02 g, 0.0470 mol) was condensed into a 10 mL
measuring cylinder at -20 C before being poured carefully into
( )-(2-Aminophenyl)chlorophenylphosphine hydrochloride, ( )-
acpp.HCl, 3. Secondary phosphine 2 (6.06 g, 0.0301 mol) was
dissolved in toluene (50 mL) and added dropwise to a stirred
suspension of PCl5 (6.27 g, 0.0301 mol) in toluene (50 mL) at
0 ◦C. The reaction mixture was stirred at this temperature for 2 h
and then allowed to warm to room temperature overnight. The
resulting white precipitate was filtered off under argon, washed
with toluene (3 ¥ 20 mL) and dried in vacuo (7.69 g, 94% assuming
the product is the mono-hydrochloride).
◦
thf (10 mL) in a dropping funnel pre-cooled with dry ice. The
solution of vinyl bromide was added dropwise to a suspension
of magnesium turnings (1.14 g, 0.0470 mol) in thf (120 mL)
containing a few drops of 1,2-dibromoethane in a 500 mL Schlenk
flask fitted with a dry ice condenser. The reaction was carefully
initiated and the vinyl bromide solution added at such a rate
that the reaction mixture gently refluxed. The reaction mixture
was heated under reflux for 1 h and allowed to cool to room
temperature.
( )-(2-Aminophenyl)(2-methoxyphenyl)phenylphosphine,
( )-
aapp, 7. The Grignard reagent (2-methoxyphenyl)magnesium
bromide was prepared by suspending magnesium turnings (2.26 g,
0.0930 mol) in thf (100 mL) followed by the slow addition of
2-bromoanisole (17.2 g, 0.0920 mol). The solution was cooled
The brown Grignard solution was added dropwise to a solution
of 3 (4.26 g, 0.0157 mol) in thf (150 mL) over a period of 1 h at
0 ◦C. The resulting brown solution was refluxed for 2 h, allowed to
cool to ambient temperature and stirred overnight. The reaction
mixture was cooled to 0 ◦C and a saturated aqueous ammonium
chloride solution (30 mL) followed by water (30 mL) were added
and the solvent removed under reduced pressure. The residue
was dissolved in water (70 mL) and dichloromethane (50 mL),
the resulting phases separated and the aqueous phase extracted
further with dichloromethane (2 ¥ 50 mL). The combined organic
extracts were dried (MgSO4), filtered and the solvent removed
under reduced pressure to give a yellow oil (3.2 g, 90%). 1H NMR
(CD2Cl2): d 4.20 (bs, 2 H, NH2); 5.59 (m, ABM portion of ABMX,
◦
to 0 C and solid 3 (6.03 g, 0.0222 mol) added in portions. The
reaction mixture was stirred overnight at ambient temperature
and subsequently heated under reflux for 2 h. The reaction
mixture was cooled to 0 ◦C and a saturated aqueous ammonium
chloride solution (50 mL) followed by water (50 mL) were
added and the resulting two phases separated. The aqueous
phase was extracted with dichloromethane (3 ¥ 60 mL) and the
combined organic extracts dried (MgSO4), filtered and the solvent
removed under reduced pressure. The residue was dissolved in
hot methanol (20 mL) to yield a white solid upon cooling. The
crystallisation was completed at -4 ◦C overnight. The crystals
were filtered off and washed with cold methanol (3 ¥ 5 mL). The
volume of the filtrate was reduced by ca. 80%, twice, and cooled
at -4 ◦C to give a further two crops of crystals (4.28 g, 68%),
mp 164–165 ◦C. (Found: C, 74.13; H, 6.18; N, 4.67. Calc. for
1 H, 3JPH = 18.1 Hz, 3JHH = 16.0 Hz, 2JHH = 2.1 Hz, CH CHH),
=
3
3
5.93 (m, ABM portion of ABMX, 1 H, JPH = 30.8 Hz, JHH
=
11.8 Hz, 2JHH = 2.1 Hz, CH CHH), 6.36–7.82 (m, 10 H, aromatics
=
and CH CH2). 31P{ H} NMR (CD2Cl2): d -10.9 (s, 1 P); d -11.0
1
=
(s, 1 P). LR-EI MS: m/z 227 (M)+, 212 (M - Me)+.
(RP*,RP*)- and (RP*,SP*)-1,2-bis[(2-aminophenyl)phenylphos-
phino]ethane, (RP*,RP*)- and (RP*,SP*)-C2-NP2N, 8. Vinylphos-
phine 5 (1.83 g, 8.07 mmol) was dissolved in thf (35 mL) and
a solution of ( )-app, 2 (1.62 g, 8.07 mmol) in thf (35 mL) was
added dropwise to the stirred solution. The reaction mixture
was treated with potassium tert-butoxide (ca. 0.15 g) and heated
under reflux for 19 d. Further potassium tert-butoxide (total 0.2 g)
was added periodically to the solution. The reaction mixture was
1
C19H18OPN: C, 74.26; H, 5.90; N, 4.56%.) H NMR (CD2Cl2):
d 3.74 (s, 3 H, OMe); 4.12 (bs, 2 H, NH2); 6.35–7.34 (m, 13 H,
1
aromatics). 31P{ H} NMR (CD2Cl2): d -31.1 (s, 1 P). LR-EI MS:
m/z 307 (M)+, 276 (M - OMe)+, 230 (M - Ph)+.
( )-(2-Aminophenyl)(2-methylphenyl)phenylphosphine, ( )-aptp,
6. The Grignard reagent (2-methylphenyl)magnesium bromide
was prepared by suspending magnesium turnings (0.76 g, 0.0314
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cooled to room temperature and treated with saturated aqueous
ammonium chloride solution (20 mL). The solvent was removed
under reduced pressure and the off-white oily residue dissolved in
water (50 mL) and dichloromethane (50 mL). The resulting phases
were separated and the aqueous phase was extracted further with
dichloromethane (3 ¥ 30 mL). The combined organic extracts were
dried (MgSO4), filtered and the solvent removed under reduced
pressure to give a pale yellow oil. Hot methanol (10 mL) was
added to the residual oil (1.98 g) and the solution cooled slowly to
room temperature. The solution was stored at -4 ◦C overnight. The
white solid that formed, unreacted 5, was filtered off under argon,
washed with cold methanol (2 ¥ 2 mL) and dried in vacuo (0.50 g).
The filtrate was taken to dryness to give a yellow oil containing
the secondary phosphine 2 and the NP2N quadridentate ligand 8.
These were separated on a silica column [15 ¥ 1.5 cm, silica gel 70–
230 mesh, eluant petroleum spirit bp 40–60 ◦C/dichloromethane,
gradient 100 : 0 → 0 : 100] under nitrogen. Fraction 1, 2 (0.52 g,
off, washed with cold aqueous ethanol (2 ¥ 5 mL, 90% w/v) and
dried in vacuo (6.54 g, 72%), mp 114.5–115 ◦C. 1H NMR (CDCl3):
d 2.82 (s, 3 H, NCH3); 4.85 (bs, 1 H, NH); 6.63–7.35 (m, 14 H,
1
1
aromatics). 31P{ H} NMR (CDCl3): d -21.9 (s, 1 P) [lit.15 31P{ H}
NMR: d -23.0].
( )-(2-Methylaminophenyl)phenylphosphine, ( )-mapp, 11.
Compound 12 (6.5 g, 0.0223 mol) was dissolved in thf (200 mL).
Lithium wire (0.50 g, 0.0721 mol) was added piece wise to the
stirred solution and the reaction mixture stirred at ambient
temperature for one week. Solid ammonium chloride (5 g) was
added to the reaction mixture followed by water (200 mL).
The resulting two phases were separated and the aqueous layer
extracted with dichloromethane (3 ¥ 80 mL). The organic extracts
dried (MgSO4), filtered and the solvent removed under reduced
pressure to give a residual oil. The product was obtained as a
clear colourless oil by distillation under reduced pressure (3.80 g,
79%), bp 135 ◦C, 0.05 mm Hg. 1H NMR (CDCl3): d 2.80 (s, 3 H,
1
32%). 1H NMR and 31P{ H} NMR spectra identical to that of an
1
NCH3); 4.25 (bs, 1 H, NH); 5.09 (d, 1 H, JPH = 222 Hz, PH);
authentic sample. Fraction 2, 8 (0.276 g, 12% based on amount of
1
6.30–7.75 (m, 9 H, aromatics). 31P{ H} NMR (CDCl3): d -60.7 (s,
1
( )-app recovered). H NMR (CD2Cl2): d 2.12 (m, 4 H, PCH2);
1 P). LR-EI MS: m/z 216 (M)+, 215 (M - H)+, 200 (215 - Me)+.
1
3.94 (bs, 4 H, NH2); 6.62–7.32 (m, 18 H, aromatics). 31P{ H} NMR
(CD2Cl2): d -31.0 (s, 2 P). LR-EI MS: m/z 428 (M)+, 351 (M -
( )-N-methyl-3-phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-one,
( )-mpbap, 9.
+
+
+
=
Ph) , 228 (M - PhPC6H4NH2) and 200 (228 - H2C CH2) . HR-
EI MS: Found for (M)+ 428.1579 (calc. for C26H26N2P2: 428.1571).
Method 1. Triphosgene (1.76 g, 5.92 mmol) was dissolved in
thf (20 mL) and a solution of secondary phosphine 11 (3.82 g,
17.7 mmol) in thf (20 mL) was added dropwise to the stirred
solution at 0 ◦C. The reaction mixture was allowed to warm
to ambient temperature and stirred overnight. The solvent was
removed under reduced pressure to leave a pale yellow solid (3.07 g,
72%). 1H NMR (CDCl3): d 3.07 (s, 3 H, NMe), 6.91–7.51 (m, 9 H,
( )-3-Phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-one, ( )-pbap,
4. Triphosgene (2.86 g, 9.64 mmol) was dissolved in thf (40 mL)
and a solution of 2 (5.77 g, 0.0287 mol) in thf (60 mL) was
added dropwise to the stirred solution at 0 ◦C. The reaction
mixture was allowed to warm to ambient temperature and stirred
overnight. The solvent was removed under reduced pressure to
leave a pale yellow solid. The latter was recrystallised from
hot toluene (100 mL) to give pale yellow crystals. These were
filtered off, washed with toluene (2 ¥ 5 mL) and dried in vacuo
(5.23 g, 80%), mp 161–162 ◦C. (Found: C, 66.91; H, 4.50; N,
6.02. Calc. for C13H10NP.0.5H2O: C, 66.10; H, 4.69; N, 5.93%.)
1H NMR (CDCl3): d 7.00–7.46 (m, 9 H, aromatics); 9.73 (bs,
1
aromatics). 31P{ H} NMR (CDCl3): d -35.7 (s, 1 P). LR-EI MS:
m/z 241 (M)+, 212 (M - HCO)+, 183 (M - HMeNCO)+. HR-EI
MS: Found for (M)+ 241.0657 (calc. for C14H12NOP: 241.0657).
Method 2. Azaphospholone 4 (0.25 g, 1.10 mmol) was dissolved
in thf (2 mL) and excess KOBut (0.25 g, 2.20 mmol) was added to
the stirred solution. The colour of the reaction mixture changed
from pale yellow to green. The reaction mixture was stirred for
0.5 h. Iodomethane (0.16 g, 1.10 mmol) was added and the
reaction mixture stirred overnight. The resultant white precipitate
was filtered off and the solvent removed under reduced pressure.
Dichloromethane (20 mL) and water (30 mL) were added, the
organic layer separated and the aqueous phase extracted twice with
dichloromethane (2 ¥ 5 mL). The combined organic extracts were
dried (MgSO4), filtered and the solvent removed under reduced
pressure to give a light yellow solid (0.15 g, 56%). NMR spectra
were identical to that described above.
1
1
1 H, NH). 31P{ H} NMR (CDCl3): d -30.9 (s, 1 P). 13C{ H}
NMR (CDCl3): d 112.5–144.0 (m, 12 C, aromatics), 187.3 (d,
1
+
=
1 C, JPC = 7.9 Hz, C O). LR-EI MS: m/z 227 (M) , 198 (M -
HCO)+, 183 (M - H2NCO)+. HR-EI MS: Found for (M)+ 227.0498
(calc. for C13H10NOP: 227.0500). IR (thin film) cm-1: n(N–H) 3160
(bs); n(C–H) 2878–3055 (m); n(C O) 1654 (s); d(N–H) 1599 (m);
n(P–C)asym 1460 (s); n(P–C)sym 1060 (m).
=
(2-Methylaminophenyl)diphenylphosphine, madpp, 12. The salt
[Li(tmeda)][2-NHC6H4PPh2 (12.5 g, 0.0312 mol)5 was suspended
in thf (400 mL) and the mixture cooled to -78 ◦C. Methyl iodide
(5.12 g, 0.0312 mol) in thf (100 mL) was added dropwise to the
stirred suspension. The solution was allowed to warm slowly to
ambient temperature and stirred overnight. The reaction mixture
was stirred overnight at room temperature. An aqueous solution of
ammonium chloride (50 mL, 20% w/v) was added to the reaction
mixture and the solvent distilled off under argon at 1 atm. Water
(200 mL) was added to the residue and the mixture extracted with
dichloromethane (3 ¥ 100 mL). The combined organic extracts
were dried (MgSO4), filtered and the solvent removed under
reduced pressure to give a pale yellow solid residue. The latter
was crystallised from hot aqueous ethanol (100 mL, 90% w/v)
to give an off-white microcrystalline solid. The solid was filtered
( )-N-benzyl-3-phenyl-1,3-dihydrobenzo[1,3]azaphosphol-2-one,
( )-bpbap, 10. Azaphospholone 4 (0.25 g, 1.10 mmol) was
dissolved in thf (2 mL) and excess KOBut (0.25 g, 2.20 mmol) was
added to the stirred solution. The reaction mixture was stirred
for 0.5 h. Benzyl bromide (0.19 g, 1.10 mmol) was added and the
reaction mixture stirred overnight. The resultant white precipitate
was filtered off and the solvent removed under reduced pressure.
Dichloromethane (20 mL) and water (30 mL) were added, the
organic layer separated and the aqueous phase extracted twice
with dichloromethane (2 ¥ 5 mL). The combined organic extracts
were dried (MgSO4), filtered and the solvent removed under
1
reduced pressure to give a light yellow solid (0.22 g, 63%). H
262 | Dalton Trans., 2010, 39, 256–264
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NMR (CDCl3): d 4.89, 4.96 (ABq, 2 H, 2JHH = 15 Hz, NCH2Ph),
[SP-4-2-(RP*,SP*)]-Chloromethylbis{3-phenyl-1,3-dihydrobenzo-
[1,3]aza-phosphol-2-one-P}platinum(II), [PtClMe(4)2]. A solu-
tion of the complex [PtClMe(cod)] (0.19 g, 0.537 mmol) in thf
(15 mL) was added dropwise to a stirred solution of 4 (0.24 g,
1.06 mmol) in thf (10 mL). The reaction mixture was stirred
for 0.5 h and n-pentane (40 mL) was added. The resulting very
pale yellow precipitate was filtered off, washed with n-pentane
(2 ¥ 2 mL) followed by diethyl ether (2 ¥ 2 mL) and dried in
vacuo (0.35 g, 95%), mp > 230 ◦C. (Found: C, 45.63; H, 3.35; N,
3.84. Calc. for C27H23ClN2O2P2Pt.0.5H2O: C, 45.74; H, 3.41; N,
1
6.83–7.51 (m, 14 H, aromatics). 31P{ H} NMR (CDCl3): d -36.3
(s, 1 P). LR-EI MS: m/z 317 (M)+, 288 (M - HCO)+, 183 (M -
HBnNCO)+. HR-EI MS: Found for (M)+ 317.0971 (calc. for
C14H12NOP: 317.0970).
(RP*,RP*)- and (RP*,SP*)-1,3-Bis[2-(phenylphosphinophenyl)-
amino]propane, (RP*,RP*)- and (RP*,SP*)-CH2[CH2NHC6H4-
PHPh]2, C3-PN2PH, 14. The quadridentate PN2P lig-
and 1,3-bis[2-(diphenylphosphinophenyl)amino]propane (4.85 g,
8.16 mmol) was dissolved in thf (350 mL). Lithium wire (0.44 g,
63.4 mmol) was added piece wise to the stirred solution and the
reaction mixture stirred for 7 d at ambient temperature. Saturated
ammonium chloride solution (50 mL) was added and the solvent
removed under reduced pressure. The residue was dissolved in
water (50 mL) and dichloromethane (150 mL) and the resulting
phases separated. The aqueous phase was extracted further with
dichloromethane (2 ¥ 50 mL). The combined organic extracts were
dried (MgSO4), filtered and the solvent removed under reduced
pressure to give an off-white solid (3.60 g, 99%). 1H NMR (CDCl3):
d 1.52 (m, 2 H, NCH2CH2); 2.82 (m, 4 H, NCH2); 4.06 (bs, 2 H,
1
3
3.95%.) H NMR [(CD3)2SO)]: d 1.16 (bs, 3 H, JPtH = 51 Hz,
3
PtMe), 7.32–8.51 (m, 18 H, aromatics), 11.16 (d, 1 H, JPH
=
13 Hz, NH), 11.65 (d, 1 H, JPH = 17 Hz, NH). 31P{ H} NMR
[(CD3)2SO)]: d -5.0 (d, 1 P, 2JPP = 15 Hz, 1JPtP = 4310 Hz), 1.3 (d,
1 P, 2JPP = 15 Hz, 1JPtP = 1625 Hz).
3
1
[SP-4-2-(RP*,SP*)]-Chloromethylbis{N-methyl-3-phenyl-1,3-di-
hydrobenzo[1,3]aza-phosphol-2-one-P}platinum(II), [PtClMe(9)2].
A solution of the complex [PtClMe(cod)] (0.12 g, 0.34 mmol) in
thf (15 mL) was added dropwise to a stirred solution of 9 (0.16 g,
0.68 mmol) in thf (10 mL). The reaction mixture was stirred for
0.5 h and n-pentane (40 mL) was added. The resulting very pale
yellow precipitate was filtered off, washed with n-pentane (2 ¥
2 mL) followed by diethyl ether (2 ¥ 2 mL) and dried in vacuo
1
NH); 5.07 (d, 2 H, JPH = 220 Hz, PH); 6.41–7.43 (m, 18 H,
1
aromatics). 31P{ H} NMR (CDCl3): d -60.3 (s, 1 P); -60.5 (s, 1 P).
LR-EI MS: m/z 442 (M)+, 333 (M–PHPh)+, 242 (333–C6H5NH)+,
201 (242–HNCH2CH2CH3)+.
◦
(0.13 g, 53%), mp > 230 C. (Found: C, 47.59; H, 3.82; N, 3.85.
1
Calc. for C29H27ClN2O2P2Pt: C, 47.84; H, 3.74; N, 3.85%). H
(RP*,RP*)- and (RP*,SP*)-1,3-Bis[1-{3-phenyl-1,3-dihydro-
benzo[1,3]azaphosphol-2-one}]propane, (RP*,RP*)- and (RP*,SP*)-
(CH2)3(pbap)2, 13.
NMR [(CD3)2SO)]: d 0.66 (bs, 3 H, PtMe), 2.62 (s, 3 H, NMe),
1
2.91 (s, 3 H, NMe), 7.14–8.13 (m, 18 H, aromatics). 31P{ H}
NMR [(CD3)2SO)]: d -5.2 (d, 1 P, 2JPP = 14 Hz,1JPtP = 4357 Hz),
0.6 (d, 1 P, 2JPP = 14 Hz, 1JPtP = 1621 Hz).
Method 1. Triphosgene (0.68 g, 2.29 mmol) was dissolved
in thf (40 mL) and a solution of (RP*,RP*)- and (RP*,SP*)-
CH2[CH2NHC6H4PHPh]2, 14 (1.51 g, 3.41 mmol) in thf (60 mL)
was added dropwise to the stirred solution at 0 ◦C. The reaction
mixture was allowed to warm to ambient temperature and stirred
overnight. The solvent was removed under reduced pressure to
leave pale yellow oil that was crystallised by trituration with
n-pentane (10 mL) to give pale yellow crystals. These were filtered
off, washed w◦ith n-pentane (2 ¥ 5 mL) and dried in vacuo (1.22 g,
[SP-4-2-(RP*,SP*)]-Chloromethylbis{N-benzyl-3-phenyl-1,3-di-
hydrobenzo[1,3]aza-phosphol-2-one-P}platinum(II), [PtClMe(10)2].
A solution of the complex [PtClMe(cod)] (0.084 g, 0.24 mmol) in
thf (10 mL) was added dropwise to a stirred solution of 10 (0.15 g,
0.47 mmol) in thf (10 mL). The reaction mixture was stirred
for 0.5 h and n-pentane (40 mL) was added. The resulting very
pale yellow precipitate was filtered off, washed with n-pentane
(2 ¥ 2 mL) followed by diethyl ether (2 ¥ 2 mL) and dried in
vacuo (0.12 g, 57%), mp > 230 ◦C. (Found: C, 55.31; H, 4.04; N,
3.39. Calc. for C41H35ClN2O2P2Pt.0.5H2O: C, 55.37; H, 4.08; N,
3.15%.) 1H NMR [(CD3)2SO)]: d 0.33 (bs, 3 H, PtMe), 3.91, 4.03
1
72%), mp 69 C. H NMR (CDCl3): d 1.90 (m, 2 H, C-CH2-C),
1
3.72 (m, 4 H, 2 ¥ NCH2), 6.69–7.45 (m, 18 H, aromatics). 31P{ H}
1
NMR (CDCl3): d -36.7 (s, 2 P). 13C{ H} NMR (CDCl3): d 25.5
(s, 1 C, C-CH2-C), 38.9 (s, 2 C, 2 ¥ NCH2),110.9–145.0 (m, 24
1
=
(ABq, 2 H, 2JHH = 18 Hz, NCH2Ph), 4.13, 4.25 (ABq, 2 H, 2JHH
=
C, aromatics), 183.8 (d, 2 C, JPC = 9.7 Hz, C O). LR-EI MS:
m/z 494 (M)+, 267 (M - ( )-pbap)+. HR-EI MS: Found for (M)+
1
18 H,z NCH2Ph), 6.58–7.77 (m, 18 H, aromatics). 31P{ H} NMR
[(CD3)2SO)]: d -4.7 (d, 1 P, 2JPP = 15 Hz, 1JPtP = 4362 Hz), 1.7 (d,
1 P, 2JPP = 14 Hz,1JPtP = 1621 Hz).
494.1312 (calc. for C29H24N2O2P2: 494.1313). IR (thin film) cm-1:
=
n(C–H) 2945–3053 (m); n(C O) 1655 (s); d(N–H) 1589 (m);
n(P–C)asym 1453 (s); n(P–C)sym 1059 (m).
Method 2. Azaphospholone 4 (0.25 g, 1.10 mmol) was dissolved
in thf (2 mL) and excess KOBut (0.25 g, 2.20 mmol) was added to
the stirred solution. The reaction mixture was stirred for 0.5 h.
1,3-Dibromopropane (0.14 g, 0.69 mmol) was added and the
reaction mixture stirred for 5 d. The solvent was removed under
reduced pressure. Dichloromethane (30 mL) and water (20 mL)
were added, the organic layer separated and the aqueous phase
extracted twice with dichloromethane (2 ¥ 5 mL). The combined
organic extracts were dried (MgSO4), filtered and the solvent
removed under reduced pressure. The residue was triturated with
n-pentane (2 mL) to give a light yellow solid (0.18 g, 65%). NMR
spectra were identical to that described above.
[SP-4-2-(RP*,SP*)]-Dichlorobis{3-phenyl-1,3-dihydrobenzo-
[1,3]aza-phosphol-2-one-P}palladium(II), [PdCl2(4)2]. A solution
of Li2[PdCl4] in methanol was prepared by reacting PdCl2
(0.2025 g, 1.14 mmol) with excess anhydrous LiCl (0.50 g,
11.8 mmol) in methanol (30 mL). The mixture was stirred for 1 h
and the resulting reddish-brown solution filtered through Celite.
A solution of 4 (0.5189 g, 2.28 mmol) in methanol (10 mL) was
added to the filtrate. The resulting golden yellow precipitate was
filtered off, washed with diethyl ether (2 ¥ 2 mL) and dried in vacuo
◦
(0.49 g, 68%), mp > 230 C. (Found: C, 48.37; H, 3.21; N, 4.29.
Calc. for C26H20Cl2N2O2P2Pd.H2O: C, 48.06; H, 3.41; N, 4.31%.)
1H NMR [(CD3)2SO)]: d 6.92–8.25 (m, 18 H, aromatics), 11.16
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Table 3 Crystallographic data for the complexes cis-[PtClMe(4)2] and
cis-[PdCl2(4)2]
related complexes trans-[PtClMe{2-Ph2PC6H4NH(SO2C6H4CH3-
4)}2] and trans-[PtClMe(PR3)2] (where R = Et or Ph).6,13,14 To
model this effect Cl and C atoms of occupancy 0.5 were placed
at each site and constraints were imposed on their positional and
anisotropic displacement factors so they would remain identical
during further refinement. The relative occupancies of Cl versus C
were refined.
cis-[PtClMe(4)2]
cis-[PdCl2(4)2]
Empirical formula
C27H23ClN2O2P2Pt.
2C3H8O
820.17
200
Monoclinic
C26H20Cl2N2O2P2Pd.
1.66CH4O.1.34 H2O
709.02
M
T/K
200
Crystal system
Space group
Crystal size/mm
Triclinic
¯
P21/a
P1
References
0.36 ¥ 0.13 ¥ 0.05
15.4641(2)
12.9680(2)
18.4124(3)
0.40 ¥ 0.08 ¥ 0.03
8.6093(2)
11.3301(3)
16.3435(5)
81.4299(12)
83.0012(16)
77.0439(16)
1529.80(7)
2
˚
a/A
1 S. O. Grim and R. C. Barth, J. Organomet. Chem., 1975, 94, 327; E. P.
Kyba, M. C. Kerby and S. P. Rines, Organometallics, 1986, 5, 1189;
F. A. Hart, J. Chem. Soc., 1960, 3324; E. Arpac and L. Dahlenberg,
Z. Naturforsch. Tiel B, 1980, 35B, 146; L. Maier, D. Seyferth, F. G. A.
Stone and E. G. Rochow, J. Am. Chem. Soc., 1957, 79, 5884; K. D.
Berlin and G. B. Butler, J. Org. Chem., 1961, 26, 2537.
˚
b/A
˚
c/A
a/◦
b/◦
g /◦
113.4788(9)
3
2 N. Weferling, Z. Anorg. Allg. Chem., 1987, 548, 55.
˚
V/A
3386.69(9)
4
1.609
4.37
69 517
7756
5069 (I > 3s(I))
3 H. Eckert and B. Forster, Angew. Chem., Int. Ed. Engl., 1987, 26, 894.
4 C. E. Barclay, G. Deeble, R. J. Doyle, S. A. Elix, G. Salem, T. L. Jones,
S. B. Wild and A. C. Willis, J. Chem. Soc., Dalton Trans., 1995, 57.
5 J. Bennett, D. A. Rae, G. Salem, N. C. Ward, P. Waring, K. Wells and
A. C. Willis, J. Chem. Soc., Dalton Trans., 2002, 234.
Z
Dc/g cm-3
1.528
0.92
34 432
7035
m/mm-1
Reflections collected
Independent reflections
Independent observed
reflections
6 J. Bennett, R. J. Doyle, G. Salem and A. C. Willis, Dalton Trans., 2006,
4614.
7 R. J. Doyle, G. Salem and A. C. Willis, J. Chem. Soc., Dalton Trans.,
1997, 2713.
4819 (I > 3s(I))
Rint
0.041
0.026, 0.030
6–55
0.043
0.028, 0.033
6–55
Final R, Rw
2q range/◦
Parameters
8 For example: J. Heinicke, K. Steinhauser, N. Peulecke, A. Spannenberg,
P. Mayer and K. Karaghiosoff, Organometallics, 2002, 21, 912; R. K.
Bansal, N. Gupta, J. Heinicke, G. N. Nikonov, F. Saguitova and D. C.
Sharma, Synthesis, 1999, 264; M. R. Mazieres, K. Rauzy, J. Bellan, M.
Sanchez, G. Pfister-Guillouzo and A. Senio, Phosphorus, Sulfur Silicon
Relat. Elem., 1993, 76, 45; K. Rauzy, M. R. Mazieres, P. Page, M.
Sanchez and J. Bellan, Tetrahedron Lett., 1990, 31, 4463; J. Heinicke,
J. Organomet. Chem., 1989, 364, C17; M. Hermesdorf, M. Birkel, H.
Heydt, M. Regitz and P. Binger, Phosphorus Sulfur Silicon, 1989, 46,
31; W. Rosch, T. Facklam and M. Regitz, Tetrahedron, 1987, 43, 3247;
K. Issleib and R. Vollmer, Z. Anorg. Allg. Chem., 1981, 481, 22.
9 A. Altomare, G. Cascarano, C. Giacovazzo, A. Guagliardi, M. C. Burla,
G. Polidori and M. Camalli, J. Appl. Crystallogr., 1994, 435.
10 D. J. Watkins, C. K. Prout, J. R. Carruthers, P. W. Betteridge and R. I.
Cooper, CRYSTALS Issue 11, Chemical Crystallography Laboratory,
Oxford, UK, 2001.
11 S. Mackay, C. J. Gilmore, C. Edwards, N. Stewart and K. Shankland,
maXus Computer Program for the Solution and Refinement of Crystal
Structures, nonius, The Netherlands, MacScience, Japan and The
University of Glasgow, 2000.
12 P. Coppens, in The Evaluation of Absorption and Extinction in
Single-Crystal Structure Analysis. Crystallographic Computing, ed.
F. R. Ahmed, S. R. Hall and C. P. Huber, Munksgaard, Copenhagen,
1970, pp 255–270.
395
400
3
1
(d, 1 H, JPH = 12 Hz, NH). 31P{ H} NMR [(CD3)2SO)]: d 28.9
(s, 2 P).
X-Ray crystallography
X-Ray diffraction data for cis-[PtClMe(4)2] and cis-[PdCl2(4)2]
were obtained on a Nonius Kappa CCD diffractometer using
Mo Ka radiation. Details of the data collections, solutions and
refinements are given in Table 3. The structures were solved using
SIR92 and refined using CRYSTALS.9,10 Analytical absorption
corrections were applied to the data for both cis-[PtClMe(4)2] and
cis-[PdCl2(4)2] (max./min. transmission factors 0.803/0.347 and
0.969/0.794, respectively).11,12
Initial solution of the structure of cis-[PtClMe(4)2] revealed
that the two non-phosphine sites on the Pt atom were of
very similar size. When incorporated as two Cl atoms their
displacement parameters were much larger than those of ad-
jacent atoms; when assigned to be two C atoms their dis-
placement parameters were very small. This suggested that
the chloro and methyl groups were disordered on the two
sites. Attempts to get them to refine to separate positions
were not successful. This has previously been reported for the
13 R. Bardi, A. M. Piazzesi and G. Bruno, Crystal Structure Communica-
tions, 1981, 10, 807.
14 S. Otto, A. Roodt and J. G. Leipoldt, S. Afr. J. Chem., 1995, 48, 114.
15 M. K. Cooper, J. M. Downes and P. A. Duckworth, Inorg. Synth., 1989,
25, 129.
16 M. K. Cooper, P. A. Duckworth, T. W. Hambley, G. J. Organ, K.
Henrick, M. McPartlin and A. Parekh, J. Chem. Soc., Dalton Trans.,
1989, 1067.
17 J. Chatt, L. M. Vallarino and L. M. Venanzi, J. Chem. Soc., 1957, 2496.
264 | Dalton Trans., 2010, 39, 256–264
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