Synthesis and characterisation of isomeric cycloaurated complexes derived from the iminophosphorane Ph3P{double bond, long}NC(O)Ph

Article abstract of DOI:10.1016/j.ica.2009.12.019

Using different organomercury substrates, two isomeric cycloaurated complexes derived from the stabilised iminophosphorane Ph₃P{double bond, long}NC(O)Ph were prepared. Reaction of Ph₃P{double bond, long}NC(O)Ph with PhCH₂

Full text of DOI:10.1016/j.ica.2009.12.019

Inorganica Chimica Acta 363 (2010) 1021–1030
Contents lists available at ScienceDirect
Inorganica Chimica Acta
journal homepage: www.elsevier.com/locate/ica
Synthesis and characterisation of isomeric cycloaurated complexes derived
from the iminophosphorane Ph3P@NC(O)Ph
*
*
Kelly J. Kilpin, Rachael A. Linklater, William Henderson , Brian K. Nicholson
Department of Chemistry, University of Waikato, Private Bag 3105, Hamilton, New Zealand
a r t i c l e i n f o
a b s t r a c t
Article history:
Using different organomercury substrates, two isomeric cycloaurated complexes derived from the stabi-
lised iminophosphorane Ph3P@NC(O)Ph were prepared. Reaction of Ph3P@NC(O)Ph with PhCH2Mn(CO)5
gave the manganated precursor (CO)4Mn(2-C6H4C(O)N@PPh3), metallated on the C(O)Ph substituent,
which yielded the organomercury complex ClHg(2-C6H4C(O)N@PPh3) by reaction with HgCl2 in
methanol. Transmetallation of the mercurated derivative with Me4N[AuCl4] gave the cycloaurated imino-
phosphorane AuCl2(2-C6H4C(O)N@PPh3) with an exo PPh3 substituent. The endo isomer AuCl2(2-C6H-
4Ph2P@NC(O)Ph) [aurated on a PPh3 ring] was obtained by an independent reaction sequence, involving
reaction of the diarylmercury precursor Hg(2-C6H4P(@NC(O)Ph)Ph2)2 [prepared from the known com-
pound Hg(2-C6H4PPh2)2 and PhC(O)N3] with Me4N[AuCl4]. Both of the isomeric iminophosphorane deriv-
atives were structurally characterised, together with the precursors (2-HgClC6H4)C(O)N@PPh3 and
(CO)4Mn(2-C6H4C(O)N@PPh3). The utility of 31P NMR spectroscopy in monitoring reaction chemistry in
this system is described.
Received 4 November 2009
Accepted 8 December 2009
Available online 16 December 2009
Keywords:
Gold complexes
Cyclometallated ligands
Iminophosphoranes
X-ray crystal structure
Organomercury compounds
Ó 2009 Elsevier B.V. All rights reserved.
1. Introduction
catalytic activity in C–O and C–C bond forming reactions evaluated
[11].
Iminophosphoranes [1,2] R3P@NR’ are attractive substrates for
cyclometallation reactions [3]; the synthesis of the ligands is sim-
ple, and the chemical and physical properties of the resulting com-
plexes can be tailored through appropriate choice of substituents R
and R0. Furthermore, the presence of phosphorus confers a power-
ful NMR spectroscopic ‘handle’ that facilitates analysis of cyclo-
metallation and ligand substitution reactions. We have been
investigating the chemistry of cycloaurated complexes, where the
presence of the cyclometallated ligand confers stability of the
gold(III) centre towards reduction [4]. The majority of ligands in
cycloaurated complexes bond through C and N donor atoms,
though we have recently described syntheses of related cycloau-
rated complexes of phosphine-sulfides 1 and triphenylphosphine
selenide 2 [5], and a related cycloaurated phosphine oxide 3 has
been reported [6]. Previously, we [7,8] and others [9] have reported
routes to N,C-cycloaurated derivatives of ‘simple’ iminophosphor-
anes Ph3P@NR 4, where R is an alkyl or aryl group. Subsequently,
the biological activity of derivatives of the cycloaurated imino-
phosphorane 4 (R = Ph), formed by displacement of the chloride li-
gands, has recently been investigated in detail [10]. Related
cationic N,N-bonded complexes (5 and 6) of pyridyl-functionalised
iminophosphoranes have also recently been synthesised, and their
In this paper we report studies on the N-acyl substituted imino-
phosphorane Ph3P@NC(O)Ph, which is stabilised towards hydroly-
sis (iminophosphoranes can hydrolyse to form phosphine oxide
and amine). While there have been a number of studies on the
coordination chemistry and cyclometallation (especially cyclopal-
ladation) reactions of stabilised iminophosphoranes [12–15] little
has been done on gold. Aguilar et al. demonstrated that when
the stabilised iminophosphoranes Ph3P@NC(O)C6H4R (R = 2-Me,
4-MeO or 2-Br) were reacted with K[AuCl4] only the N-coordinated
adducts 7 could be obtained, and heating did not result in
cycloauration [9]. Here we describe how the use of two different
organomercury derivatives of the stabilised iminophosphorane
Ph3P@NC(O)Ph can be utilised in the synthesis of isomeric exo
and endo-cycloaurated derivatives, with the P atom respectively
outside and inside the cycloaurated ring.
2. Results and discussion
2.1. Synthesis of stabilised ortho-mercurated and cycloaurated
iminophosphoranes
The synthesis of stabilised iminophosphoranes is summarised
in Scheme 1. Ph3P@NC(O)Ph [16] was synthesised from Ph3P and
PhC(O)N3 using the conventional Staudinger reaction, while
Ph3P@NC(O)But was synthesised by a modified version of the same
* Corresponding authors. Fax: +64 7 838 4219 (W. Henderson).
E-mail address: w.henderson@waikato.ac.nz (W. Henderson).
0020-1693/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2009.12.019

1022
K.J. Kilpin et al. / Inorganica Chimica Acta 363 (2010) 1021–1030
reaction. Frøyen had previously demonstrated that iminophos-
phoranes could conveniently be synthesised by the one-pot reac-
tion between an acid chloride, sodium azide and triphenyl-
phosphine [17]. We have found that exchanging the acid chloride
for an anhydride gives the same product, though the reaction times
are longer because the anhydride is less reactive. Ph3P@NC(O)But
has been recently synthesised for the first time through imido
transfer reaction between the N-phenacyl iminodibenzothiophene
8 and PPh3 [18]. Ph3P@NC(O)But is an air stable crystalline solid
with 1H NMR and IR spectroscopic data consistent with the
literature.
compound metallated on a PPh3 ring) is an interesting synthetic
problem. Aguilar et al. have shown that the reaction of
Ph3P@NC(O)C6H4R with K[AuCl4] gave the coordination com-
pounds 7 where the nitrogen of the iminophosphorane acts as a
simple two electron donor to the gold centre [9]. In cyclopallada-
tion reactions of Ph3P@NC(O)R (R = Ph or substituted aryl), a strong
preference for exo palladation was found, i.e. metallation of the
NC(O)-bonded aryl ring [12,13].
We considered that transmetallation from the corresponding
ortho-mercurated complex would be a viable option for the syn-
thesis of cycloaurated derivatives of Ph3P@NC(O)Ph. However,
the presence of the carbonyl group on the ligand means that syn-
thesis of the ortho-mercurated compound via the ortho-lithiated
The cycloauration of stabilised iminophosphoranes (to give
either the exo product metallated on the C(O)Ph group, or the endo
R
PPh
N
3
+
Ph
Ph
R
R
i
N
E
Pr N
Ph
P
2
P
O
P
X
AuCl
2
AuCl
2
AuCl
AuCl
2
2
N
1a E = S, R = Ph
1b E = S, R = NEt
2 E = Se, R = Ph
4
3
2
5a, X = CH
2
5b, X = CO
O
R
H C
3
+
O
N
S
C
Ph
Ph
O
N
HgCl
P
PPh
3
AuCl
N
2
N
AuCl
3
R
9
7 R = 2-Me, 4-OMe, 2-Br).
8
6a, R = Ph
6b, R = COPh
Ph
Ph
Ph
EtO
Ph
Ph
S
N
O
P
C
P
HgCl
Mn(CO)
HgCl
4
10
11
18
O
O
-N2
(a)
PPh3
Ph3
P
N3
Ph
N
Ph
O
O
O
(b)
-N2
NaN3
ButCOONa
PPh3
N
But
Ph3
P
B
ut
O
But
Scheme 1. Synthesis of the stabilised iminophosphoranes (a) Ph3P@NC(O)Ph and (b) Ph3P@NC(O)But.

K.J. Kilpin et al. / Inorganica Chimica Acta 363 (2010) 1021–1030
1023
compound (i.e. the method we previously used for the synthesis of
simple ortho-mercurated iminophosphoranes) [7,8] is no longer
viable. Unfortunately, attempts at direct mercuration of
Ph3P@NC(O)Ph with Hg(OAc)2 in refluxing THF, analogous to the
successful direct mercuration of Ph3P@NPh on the N-phenyl ring
[19], were also unsuccessful. It is possible that the use of a stronger
mercurating agent [e.g. Hg(ClO4)2 or Hg(OTf)2] could produce the
organomercury complex, however this was not attempted.
Organomanganese chemistry was therefore utilised. Cooney
et al. have previously demonstrated that reaction of ortho-manga-
nated acetophenone with HgCl2 gave ortho-mercurated acetophe-
none 9 in good yields [20]. This compound cannot be synthesised
by conventional methods – again, the presence of a carbonyl group
excludes the use of organolithium reagents and direct mercuration
occurs at the methyl carbon due to keto-enol tautomerisation. We
have recently extended this methodology to the synthesis of ortho-
mercurated triphenylphosphine sulfide 10, which was used in the
synthesis of the cycloaurated phosphine sulfide 1a [5]. Therefore
ortho-manganation of Ph3P@NC(O)Ph was investigated as a route
to the ortho-mercurated derivative.
The simple iminophosphorane Ph3P@NPh is known to undergo
ortho-metallation with PhCH2Mn(CO)5 in refluxing heptane to give
the manganated compound 11 [21]. However, the stabilised imino-
phosphorane Ph3P@NC(O)Ph underwent manganation at the ortho
position of the NC(O)-bonded phenyl ring to give the exo isomer
12, Scheme 2. The geometry was initially assigned by NMR and
IR spectroscopies; the 31P{1H} NMR spectrum showed a single peak
at 23.5 ppm, only slightly shifted from the free ligand (21.3 ppm),
strongly suggesting ortho-metallation on the N–C(O)Ph group.
The 31P chemical shift of the endo isomer would be expected to
be much further downfield because the phosphorus would be
incorporated into a five-membered ring [22]. The 13C{1H} spectrum
showed the correct number of signals for metallation of the NC(O)-
bonded substituent. The carbonyl carbon of 12 appears at
189.0 ppm, shifted from the free ligand (d 176.4 ppm), suggesting
that the oxygen atom is coordinated to manganese. The C@O
stretch in the IR spectrum of 12 occurs at 1488 cmꢀ1, (compared
to 1595 cmꢀ1 in the uncoordinated ligand), which suggests that
the oxygen atom is coordinated. The mechanism of ortho-manga-
nation is not well understood so it is unclear why metallation oc-
curs on the N-acyl ring with the oxygen atom acting as the
neutral donor. However the reaction of N,N-dialkylbenzamides
with PhCH2Mn(CO)5 also gave the isomer with the oxygen coordi-
nated to the manganese, though in this case the nitrogen would be
expected to have poor donor ability [23].
Fig. 1. Molecular structure of (CO)4Mn(2-C6H4C(O)N@PPh3), 12. Hydrogen atoms
have been excluded for clarity. Thermal ellipsoids are shown at the 50% probability
level.
Table 1
Selected bond lengths (Å) and angles (°) for the complex (CO)4Mn-
(2-C6H4C(O)N@PPh3) 12 with esds in parentheses.
Atoms
Lengths (Å)
Atoms
Angles (°)
Mn(1)–C(11)
Mn(1)–O(1)
P(1)–N(1)
C(1)–N(1)
C(1)–O(1)
2.0513(14)
2.0458(10)
1.6213(12)
1.333(2)
O(1)–Mn(1)–C(11)
Mn(1)–O(1)–C(1)
Mn(1)–C(11)–C(16)
N(1)–C(1)–O(1)
80.17(5)
115.92(8)
111.82(10)
123.84(12)
118.88(9)
1.277(2)
P(1)–N(1)–C(1)
clic ring is planar to within 0.04 Å, with the adjacent C(11)–C(16)
ring bent only 3.4° from the plane. The Mn(1)–C(1) and Mn(1)–
O(1) distances of 2.0513(14) and 2.0458(10) Å respectively, are in
the range found for other cyclomanganated acyl–arenes [24]
although usually the Mn–C bond is slightly shorter than the Mn–
O one. The C(1)–O(1) bond of 1.277(2) Å is 0.032 Å longer than in
the free ligand, consistent with the drop in the m(CO) stretching fre-
quency seen in the infrared spectrum of 12. The P(1)–N(1) and
C(1)–N(1) bond lengths are essentially unchanged from the free li-
gand [25], as expected given their largely spectator role in the
cyclometallation. The bite angle of the ligand acting as a C,O-donor
is 80.17(5)°, very similar to that for the cycloaurated example 14
where there is C,N-coordination (see below); for the latter example
the Au–C and Au–N distances are essentially the same as the Mn–C
Unambiguous characterisation of 12 was achieved by an X-ray
crystal structure determination. As suggested by spectroscopic
investigations, the manganese is attached in the ortho position of
the phenacyl ring with the carbonyl oxygen acting as a neutral do-
nor. The molecular structure is shown in Fig. 1, and selected bond
lengths and angles are in Table 1. The five-membered manganacy-
PPh3
PPh3
N
PPh3
N
N
O
O
O
PhCH2Mn(CO)5
HgCl2
[Me4N][AuCl4]
Ph3P=NC(O)Ph
Mn(CO)4
HgCl
AuCl2
Δ
[Me4N]Cl
MeCN
n
, -heptane
Δ
, MeOH
12
13
14
Scheme 2. Synthesis of exo-cyclometallated complexes from the stabilised iminophosphorane Ph3P@NC(O)Ph.

1024
K.J. Kilpin et al. / Inorganica Chimica Acta 363 (2010) 1021–1030
and Mn–O ones in 12, so the puckering of the ring in 14 cannot be
attributed to different sizes of the metal atoms. Rather it appears
that the puckering arises from a twist to minimise the interactions
between the adjacent C@O and N@P bonds in 14. In 12 the CO li-
gand trans to the O donor has a noticeably shorter Mn–C and a
longer C–O distance than the other three COs.
As anticipated, reaction of 12 with HgCl2 in refluxing methanol
gave the ortho-mercurated complex 13 in good yield, Scheme 2.
Transmetallation with Me4N[AuCl4]/Me4NCl, analogous to the
method used for the synthesis of a range of other organo-gold com-
pounds [26,27], including simple cycloaurated iminophosphoranes
[7,8], gave the exo-cycloaurated complex 14, also in good yield.
Me4NCl was added to transmetallation reaction mixtures to pro-
mote cycloauration by the formation of sparingly soluble
(Me4N)2[Hg2Cl6] [26–28]. Interestingly, the transmetallation
reaction from 13 to 14 took two days – much slower than the cor-
responding reactions for simple iminophosphoranes [7,8], presum-
ably because the neighbouring carbonyl group pulls electron
density away from the nitrogen atom.
To synthesise the endo isomer, containing a cycloaurated PPh3
group, a different organomercury precursor was used; the syn-
thetic procedure is depicted in Scheme 3. Bennett et al. have previ-
ously synthesised the diarylmercury compound 15, which reacted
with H2O2 or sulfur to give the phosphine oxide or sulfide, respec-
tively, and with BH3.SMe2 to give the borane complex [29,30].
When 15 was reacted with two equivalents of PhC(O)N3, as per
the Staudinger reaction, the new iminophosphorane derivative 16
was obtained. The reaction however took longer than expected –
typically when a phosphine is added to the azide rapid evolution
of nitrogen occurs. When the mechanism of the Staudinger reaction
is considered [2], it is not surprising that the reaction was sluggish
– sterically bulky groups hinder the formation of the four-mem-
bered transition state. Again, transmetallation with Me4N[AuCl4]/
[Me4N]Cl gave the endo-cycloaurated compound 17, by a slower
reaction than for the simple iminophosphoranes 4.
Fig. 2. Molecular structure of ClHg(2-C6H4C(O)N@PPh3) 13 showing the atom
numbering scheme. Hydrogen atoms have been omitted for clarity and thermal
ellipsoids are shown at the 50% probability level.
2.2.1. ClHg(2-C6H4C(O)N@PPh3) 13
Interestingly, as with the manganese complex 12, it is the oxy-
gen that is interacting with the metal centre. In this example, the
somewhat surprising preference for the hard oxygen donor may
be because of steric reasons. The molecules of the mercury com-
plex are packed together so that there are weak intermolecular
interactions (3.143 Å) between the metal and a chlorine atom of
a neighbouring molecule – in essence a dimeric structure is present
in the solid state. If however there was an interaction between the
nitrogen and the mercury the bulky triphenylphosphine group
would twist around and sit over the metal centre and ‘‘clash” with
the phenacyl phenyl ring on the adjacent molecule.
As expected, the coordination around the mercury shows only a
slight deviation from linearity [the C(2)–Hg(1)–C(1) angle is
176.24(6)°]. Although the mercury–oxygen interaction is weak
[Hg(1)ꢁꢁꢁO(1) 2.6281(16) Å] it is significantly shorter than in merc-
urated ethyl benzoate 18 [2.734 Å] [31] and the mercurated aceto-
phenone 9 [2.712 Å] [20] and is sufficient to keep the core of the
molecule co-planar. Indeed the greatest deviations from the metal-
lacyclic ring are C(1) and C(2) [which sit 0.0254(15) and
0.0338(13) Å above and below the plane of the ring, respectively].
The PNCO network is also essentially planar but tilted upward at
In contrast, when Ph3P@NC(O)But was reacted with PhCH2-
Mn(CO)5 in refluxing heptane no reaction occurred, even after
8 h. In addition, reaction of Ph3P@NC(O)Ph with two equivalents
of PhCH2Mn(CO)5, in an attempt to make a di-cyclomanganated
complex, only gave the mononuclear compound 12. It appears that
the P-bonded phenyl rings of stabilised iminophosphoranes are in-
ert towards manganation.
2.2. X-ray crystal structures of ClHg(2-C6H4C(O)N@PPh3) 13, AuCl2-
(2-C6H4C(O)N@PPh3) 14 and AuCl2(2-C6H4Ph2P@NC(O)Ph) 17
The molecular structures of 13, 14 and 17 are shown in Figs. 2–
4, respectively and important structural parameters are presented
in Tables 2–4.
C(O)Ph
C(O)Ph
N
Ph
Ph
Ph
Ph
N
Ph
Ph
P
P
P
[Me4N][AuCl4]
PhC(O)N3
CH2Cl2
AuCl2
Hg
Hg
[Me4N]Cl
MeCN
P
Ph
Ph
P
Ph
Ph
N
C(O)Ph
15
16
17
Scheme 3. Synthesis of endo-cyclometallated complexes.

K.J. Kilpin et al. / Inorganica Chimica Acta 363 (2010) 1021–1030
1025
Table 2
Selected bond lengths (Å) and angles (°) for the complex ClHg(2-C6H4C(O)N@PPh3) 13
with esds in parentheses.
Atoms
Lengths (Å)
Atoms
Angles (°)
P(1)–N(1)
N(1)–C(7)
C(7)–O(1)
C(7)–C(1)
C(1)–C(2)
C(2)–Hg(1)
Hg(1)–Cl(1)
Hg(1)ꢁꢁꢁO(1)
1.620(2)
1.346(3)
1.250(3)
1.515(3)
1.398(3)
2.063(2)
2.3293(6)
2.6281(16)
C(2)–Hg(1)–Cl(1)
Hg(1)–C(2)–C(1)
C(2)–C(1)–C(7)
C(1)–C(7)–O(1)
C(7)–O(1)–Hg(1)
C(1)–C(7)–N(1)
C(7)–N(1)–P(1)
N(1)–C(7)–O(1)
176.24(6)
118.83(17)
120.9(2)
119.80(19)
106.40(14)
114.86(19)
118.37(16)
125.3(2)
Table 3
Selected bond lengths (Å) and angles (°) for the complex AuCl2(2-C6H4C(O)N@PPh3)
14, with esds in parentheses.
Atoms
Lengths (Å)
Atoms
Angles (°)
P(1)–N(1)
N(1)–C(7)
C(7)–O(1)
C(7)–C(1)
C(1)–C(2)
C(2)–Au(1)
Au(1)–Cl(1)
Au(1)–Cl(2)
Au(1)–N(1)
1.655(3)
1.401(4)
1.218(4)
1.481(4)
1.395(4)
2.025(3)
2.3694(8)
2.2798(8)
2.048(3)
Cl(1)–Au(1)–Cl(2)
Cl(2)–Au(1)–C(2)
C(2)–Au(1)–N(1)
N(1)–Au(1)–Cl(1)
Au(1)–C(2)–C(1)
C(2)–C(1)–C(7)
C(1)–C(7)–N(1)
C(1)–C(7)–O(1)
O(1)–C(7)–N(1)
C(7)–N(1)–Au(1)
C(7)–N(1)–P(1)
P(1)–N(1)–Au(1)
90.18(3)
93.24(9)
80.90(11)
95.55(7)
111.7(2)
117.0(3)
112.0(3)
125.7(3)
122.3(3)
112.8(2)
119.5(2)
127.68(16)
Table 4
Selected bond lengths (Å) and angles (°) for the complex AuCl2(2-C6H4Ph2P@NC(O)Ph)
17, with esds in parentheses.
Fig. 3. Molecular structure of the exo isomer AuCl2(2-C6H4C(O)N@PPh3) 14
showing the atom numbering scheme. The dichloromethane solvent and hydrogen
atoms have been omitted for clarity. Thermal ellipsoids are shown at the 50%
probability level.
Atoms
Lengths (Å)
Atoms
Angles (°)
Au(1)–Cl(1)
Au(1)–Cl(2)
Au(1)–C(12)
Au(1)–N(1)
P(1)–N(1)
N(1)–C(7)
C(7)–O(1)
C(12)–C(11)
C(11)–P(1)
2.3578(6)
2.2721(6)
2.039(3)
2.0321(18)
1.645(2)
1.401(3)
1.222(3)
1.412(3)
1.777(2)
Cl(1)–Au(1)–Cl(2)
Cl(2)–Au(1)–C(12)
C(12)–Au(1)–N(1)
N(1)–Au(1)–Cl(1)
C(12)–C(11)–P(1)
C(11)–P(1)–N(1)
P(1)–N(1)–Au(1)
P(1)–N(1)–C(7)
90.89(2)
92.59(7)
84.38(9)
91.97(6)
115.72(17)
99.18(10)
111.98(9)
116.59(15)
119.1(2)
N(1)–C(7)–O(1)
N(1)–C(7)–C(1)
118.96(19)
an angle of 6.84(17)° to the metallacyclic ring meaning that the
molecule has a slight bow in it. This differs from the free ligand
[25] where the phenyl ring is twisted 11.49° from the planar PNCO
moiety. As in the uncoordinated ligand, the triphenylphosphine
groups have a propeller-like arrangement.
2.2.2. AuCl2(2-C6H4C(O)N@PPh3) 14
In this complex, the nitrogen of the iminophosphorane is now
coordinated to the gold centre. This preference for coordination
of the softer nitrogen to the metal centre was also observed in
the analogous cyclopalladated complex of the same ligand [12].
As for the palladium complex, the metallacyclic ring is not planar;
instead it has an envelope conformation with the gold atom sitting
0.528(5) Å above the ring, resulting in a twisted (19.11°) PNCO net-
work, as discussed above. The dangling triphenylphosphine moiety
has phenyl groups which are arranged in a propeller-like fashion.
Upon coordination to the gold there is an increase in both the
P@N and N–C bond lengths when compared to the uncoordinated
ligand [25] [P@N: 1.626(3) Å in ligand, 1.655(3) Å in 14; N–C:
1.353(5) Å in ligand, 1.401(4) Å in 14]. In addition the C@O bond
length has decreased [from 1.245(5) Å in the ligand to 1.218(4) Å
in the cycloaurated complex] – a similar change in bond lengths
was observed in cyclopalladated complexes of such ligands [12,13].
Fig. 4. Molecular structure of the endo isomer AuCl2(2-C6H4Ph2P@NC(O)Ph) 17
showing the atom numbering scheme. Hydrogen atoms have been omitted for
clarity and thermal ellipsoids are shown at the 50% probability level.

1026
K.J. Kilpin et al. / Inorganica Chimica Acta 363 (2010) 1021–1030
The coordination around the gold atom is square–planar, as ex-
2.3578(6) vs. 2.2721(6) Å. Furthermore, the Au–Cl bond trans to
the nitrogen is slightly shorter in 17 than it is in 14 [2.2798(8) Å]
and 4 (R = Ph) [2.289(1) Å], indicating than an acyl group on the
nitrogen results in the nitrogen having a lower trans influence.
The Au–N bond length of the endo complex [2.0321(18) Å] is signif-
icantly shorter than in the exo complex [2.048(3) Å] and is compa-
rable to that in the cationic pyridyl analogue 6b [2.030(3) Å] [11].
The Au–Cl bond trans to the NC(O)Ph group of 6b [bond length
2.2636 Å] is shorter than that in 14, presumably reflecting the cat-
ionic nature of 6b, and the lower cis-influence of a nitrogen-donor
pyridyl ring in 6b compared to a carbon-donor phenyl in 12.
pected; the bite angle of the ligand is 80.90(11)°. The greatest devi-
ation from the mean coordination plane is C(2) which is
0.0906(15) Å below the plane. As with other crystallographically
characterised gold(III) complexes containing C,N donor ligands
[4] the Au–Cl(1) bond trans to the carbon (which has a higher trans
influence) is longer [2.3694(8) Å] than the Au–Cl(2) bond trans to
the nitrogen [2.2798(8) Å]. These compare favourably with Au–Cl
bond distances of 2.368(1) and 2.289(1) Å in the phenyl-substi-
tuted iminophosphorane 4 (R = Ph) [7].
The compound crystallises with a molecule of dichloromethane
held in the lattice by interaction of a hydrogen on the dichloro-
methane with the two chloride ligands on the gold complex (i.e.
a bifurcated hydrogen bond).
2.3. Spectroscopic and mass spectrometric characterisation of ortho-
mercurated and cycloaurated stabilised iminophosphoranes
2.2.3. AuCl2(2-C6H4Ph2P@NC(O)Ph) 17
2.3.1. Spectroscopy of exo complexes
The X-ray crystal structure of 17 confirms the formation of the
endo isomer with the P@N bond contained in the metallacyclic
ring. The environment around the gold is again essentially square
planar, as expected. Like the simple iminophosphorane complexes
4, the metallacyclic ring is severely puckered with the phosphorus
and the nitrogen atoms showing the greatest deviations from the
plane [P(1) sits 0.2369(9) Å below the plane, N(1) 0.2880(9) Å
above the plane]. As a result of the puckering, the PNCO moiety
is no longer planar and has a twist of 24.97°. The bite angle of
the ligand [84.38(9)°] is similar to what is seen in the simple imi-
nophosphorane complexes 4 [7,8].
As with the exo isomer, the C@O bond length is shorter in the
cycloaurated species [1.222(3) Å] than in the free ligand
[1.245(5) Å] [25]. This coincides with the P@N and N(1)-C(7) bonds
becoming longer and is a result of loss of conjugation as the elec-
tron density is pulled onto the gold atom. The Au–Cl bond trans
to C is again the longer of the two Au–Cl bond distances,
As observed previously [7,8], 31P{1H} NMR spectroscopy is very
indicative of the ligand coordination mode in iminophosphorane
complexes. Fig. 5 shows the 31P{1H} NMR spectra of the series of
complexes en route to the exo-cyclometallated complex 14. The
parent ligand Ph3P@NC(O)Ph has a chemical shift of 21.3 ppm
and the ortho-manganated complex 12 has a shift of 23.5 ppm –
there is essentially no change between the two. This indicates that
the phosphorus atom is not part of the metallacyclic ring [22].
There is little change on transmetallation to the ortho-mercurated
complex – the chemical shift of 13 is 26.6 ppm. There are no satel-
lite lines due to 199Hg coupling, because the mercury atom is sep-
arated from the phosphorus by five bonds. The cycloaurated
complex 14 has a chemical shift of 35.8 ppm which is slightly
shifted from the manganese and mercury precursors. This is most
probably because the nitrogen is now coordinated to gold so the
phosphorus (which is directly bonded to the nitrogen) is slightly
more deshielded than in the other examples where the oxygen is
Ph3P=NC(O)Ph
12
13
14
Fig. 5. 31P{1H} NMR spectra of the series of exo-cyclometallated complexes and Ph3P@NC(O)Ph.

K.J. Kilpin et al. / Inorganica Chimica Acta 363 (2010) 1021–1030
1027
coordinated to the metal. The chemical shift in 14 is significantly
further upfield than in the simple cycloaurated iminophosphorane
4 (R = Ph) (65.5 ppm) [7] where the phosphorus is in the five-mem-
bered ring.
chemical shift is very close to the exo isomer 13 but now 199Hg sa-
tellite peaks can also be seen – the 3JHgP coupling constant (171 Hz)
indicates that the mercury is attached at the ortho position of one
of the P-bonded phenyl rings [compare
4 (R = Ph) where
Infrared spectroscopy can also be used to determine the binding
mode of iminophosphoranes; IR data are summarised in Table 5. It
has previously been reported that when stabilised iminophosphor-
anes form cyclometallated complexes with a nitrogen–metal bond
the P@N stretch moves to lower energies and the C@O stretch
moves to slightly higher energies [12,14]. In Ph3P@NC(O)Ph the
P@N stretch occurs at 1341 cmꢀ1 and the C@O stretch at
1595 cmꢀ1. The ortho-mercurated exo complex 13 (in which the
nitrogen is not involved in any interactions with the mercury)
3JHgP = 326 Hz]. Upon transmetallation to gold in 17 there is a sig-
nificant downfield shift (of approximately 30 ppm) as the phos-
phorus is now in a five-membered ring. The chemical shift of
60.5 ppm is now comparable with the cycloaurated iminophos-
phorane 4 (R = Ph) (65.6 ppm) [7]. Fig. 6 shows the 31P{1H} chem-
ical shifts associated with the endo complexes.
The endo series of complexes show different IR spectroscopic
behaviour (Table 5) to that of the exo isomers. The P@N stretch
of 16 occurs at 1323 cmꢀ1, approximately 20 cmꢀ1 lower than in
the free ligand, which suggests an interaction between the nitro-
gen and the mercury. Upon transmetallation to gold, there is a fur-
ther decrease to 1282 cmꢀ1. This pattern is analogous to that seen
in the simple iminophosphorane complexes 4 [7,8]. There is little
change between the C@O stretches in Ph3P@NC(O)Ph and the
ortho-mercurated complex 16, however in the cycloaurated com-
plex 17 the C@O stretch occurs at higher wavenumbers, again be-
cause of loss of conjugation in the metallacycle.
has a P@N stretch at 1340 cmꢀ1 and a C@O stretch at 1532 cmꢀ1
.
The P@N shift remains relatively unchanged, but the C@O shift
has moved to lower wavenumbers because of a slight interaction
with the mercury. In contrast, the cycloaurated exo complex 14
has a P@N stretch at 1285 cmꢀ1; the significant shift to lower
wavenumbers is consistent with the ligand coordinating through
the nitrogen atom. The C@O stretch occurs at 1684 cmꢀ1, the high-
er energy stretch associated with the loss of conjugation that is
present in the ligand.
3. Conclusion
2.3.2. Spectroscopy of endo complexes
The diarylmercury complex 15 has a 31P{1H} NMR chemical
shift of 0.4 ppm and the di-iminophosphorane 16 undergoes a sig-
nificant shift to 27.4 ppm upon conversion of P(III) to P(V). The
By appropriate choice of organomercury precursor we have syn-
thesised two isomeric cycloaurated complexes of the iminophos-
phorane Ph3P@NC(O)Ph. Specifically, by controlling the order of
metallation with respect to phosphine ? iminophosphorane con-
version, the site of metallation can be controlled. Organomanga-
nese chemistry has been successfully used in the synthesis of
organomercury and -gold complexes, extending the synthetic util-
ity of these reagents.
Table 5
Selected IR absorbances (KBr disk) for the iminophosphorane Ph3P@NC(O)Ph and
derivatives thereof, including endo and exo isomers.
Complex
IR absorbances (cmꢀ1
(P@N)
)
m
m(C@O)
Ph3P@NC(O)Ph
1341
1341
1340
1285
1323
1282
1595
1488
1532
1684
1598
1641
4. Experimental
12
13
14
16
17
Safety note: CAUTION! Azides are hazardous materials that
should be handled with caution, using appropriate procedures
[32].
15
16
17
Fig. 6. 31P{1H} NMR spectra of the series of endo-cyclometallated complexes. The presence of 3JHgP coupling can be observed for complexes 15 and 16 as weak satellite peaks.

1028
K.J. Kilpin et al. / Inorganica Chimica Acta 363 (2010) 1021–1030
4.1. Materials and methods
O
MLx
2
The compounds PhCH2Mn(CO)5 [24] and Hg(2-C6H4PPh2)2
[29,30] were prepared by literature methods. Ph3P@NC(O)Ph was
prepared from PPh3 and PhC(O)N3 by the Staudinger reaction
[15]. Pivalic anhydride (Aldrich), tetramethylammmonium chlo-
ride (BDH) and sodium azide (BDH) were used as supplied; other
reagents were at least of LR grade.
7
1
3
4
11
P
N
8
9
6
10
3
5
Scheme 4. NMR labelling scheme for the exo-series complexes 12 (MLx = Mn(CO)4),
13 (MLx = HgCl) and 14 (MLx = AuCl2).
General experimental techniques were as previously described
[33]. Metallation reactions were carried out under a nitrogen
atmosphere using standard Schlenk techniques [34], with light also
being excluded in the case of cycloauration reactions. High resolu-
tion ESI mass spectra were recorded on a Bruker Daltonics MicrO-
TOF instrument, calibrated using a solution of sodium formate.
Samples were dissolved in a few drops of CH2Cl2 prior to dilution
with methanol, and infused by a syringe pump.
Calc. for C29H19NO5PMn: C, 63.6; H, 3.5; N, 2.6. Found: C, 64.8; H,
3.8; N 2.6%. NMR (see Scheme 4 for the labelling system): 1H d
7.13 (t, 1H, H-5), 7.33 (t, 1H, H-4), 7.51 (m, 6H, H-10), 7.62 (m,
3H, H-11), 7.75 (m, 6H, H-9), 7.90 (d, 1H, H-3), 8.09 (d, 1H, H-6);
1
3
13C{1H} d 123.1 (C-5), 127.2 (d, JPC 100.1 Hz, C-8), 128.9 (d, JPC
4
12.6 Hz, C-10), 129.3 (C-6), 131.8 (C-4), 132.9 (d, JPC 3.1 Hz, C-
11), 133.2 (d, JPC 10.1 Hz, C-9), 140.9 (C-3), 143.3 (d, JPC
2
3
4.2. Synthesis of [Me4N][AuCl4]
4
2
16.6 Hz, C-1), 181.2 (d, JPC 2.8 Hz, C-2), 189.0 (d, JPC 10.7 Hz, C-
7), 213.4 (C@O), 214.8 (C@O), 221.8 (C@O); 31P{1H} d 23.5 ppm.
ESI-MS (ꢀve): m/z: 553.958 (100%, [MꢀCO+Cl]ꢀ, calc 554.012),
581.949 (90%, [M+Cl]ꢀ, calc 582.007), 525.968 (25%, [Mꢀ2CO+Cl]ꢀ,
To an aqueous (50 mL) solution of H[AuCl4]ꢁ4H2O (2.00 g,
4.85 mmol) excess [Me4N]Cl (0.65 g) was added. A yellow precipi-
tate formed immediately and the resulting suspension was stirred
for a further 30 min. The mixture was filtered and the bright yellow
solid washed with copious amounts of water followed by ethanol
and diethyl ether. Drying under vacuum gave [Me4N][AuCl4] in
near quantitative yields.
calc 526.017). IR:
m(P@N) 1341 (vs), m .
(C@O) 1488 (s) cmꢀ1
4.5. Synthesis of ClHg(2-C6H4C(O)N@PPh3) 13
(CO)4Mn(2-C6H4C(O)N@PPh3) 12 (0.200 g, 0.37 mmol) and
HgCl2 (0.199 g, 0.73 mmol) were refluxed in methanol (20 mL)
for 5 h during which time the yellow solution became colourless
and a white solid formed. The mixture was cooled in ice then fil-
tered and the white solid washed well with cold methanol. The so-
lid was redissolved in dichloromethane (50 mL) and filtered
through a column of celite. The resulting clear solution was re-
duced in volume (ꢂ5 mL) and diethyl ether was added dropwise
until the solution went cloudy. Storage at ꢀ20 °C gave white crys-
tals of ClHg(2-C6H4C(O)N@PPh3) (0.129 g, 57%). Anal. Calc. for
C25H19NOPClHg: C, 48.7; H, 3.1; N, 2.3. Found: C, 48.9; H, 3.1; N,
2.3%. NMR (see Scheme 4 for the labelling system): 1H d 7.36 (m,
1H, H-5), 7.38 (m, 1H, H-3), 7.48 (m, 1H, H-4), 7.51 (m, 6H, H-
10), 7.60 (m, 3H, H-11), 7.79 (m, 6H, H-9), 8.49 (m, 1H, H-6);
4.3. Synthesis of Ph3P@NC(O)But
Pivalic anhydride (2.0 mL, 9.9 mmol) and sodium azide (0.769 g,
11.8 mmol) were stirred in dry, degassed acetone (100 mL) for
10 min. PPh3 (2.59 g, 9.9 mmol) was added in one portion and
the resulting solution was stirred at room temperature for 72 h.
The solvent was removed under reduced pressure and the solid
extracted into dichloromethane (40 mL) and filtered. Diethyl ether
(60 mL) was added and the solution was stored at ꢀ25 °C.
Ph3P@NC(O)But crystallised as white crystals (2.20 g, 62%). Found:
C 76.3, H 6.8, N 3.8; C23H24NOP requires C 76.4, H 6.7, N 3.9%. NMR:
1H d 1.29 (s, 9H, H-1), 7.44 (m, 6H, H-5), 7.53 (m, 3H, H-7), 7.74 (m,
6H, H-6); 13C{1H} d 28.8 (s, C-1), 41.4 (d, JPC 17.2 Hz, C-2),
3
3
1
1
3
13C{1H} d 127.5 (d, JPC 99.9 Hz, C-8), 128.3 (C-5), 129.0 (d, JPC
128.6 (d, JPC 12.0 Hz, C-6), 129.2 (d, JPC 98.8 Hz, C-4), 131.9 (d,
2
2
4JPC 2.9 Hz, C-7), 133.1 (d, JPC 9.8 Hz, C-5), 190.6 (d, JPC 11.0 Hz,
C-3); 31P{1H} d 18.3 ppm. ESI-MS: m/z: 362.167 (100%, [M+H]+,
calc 362.169), 384.148 (47%, [M+Na]+, calc 384.149), 745.308
4
12.3 Hz, C-10), 130.8 (C-6), 131.5 (C-4), 132.7 (d, JPC 2.5 Hz, C-
2
3
11), 133.5 (d, JPC 10.5 Hz, C-9), 136.2 (C-3), 142.9 (d, JPC
4
2
18.5 Hz, C-1), 150.1 (d, JPC 3.7 Hz, C-2), 177.6 (d, JPC 7.7 Hz, C-
7); 31P{1H} d 26.6 ppm. ESI-MS: m/z: 640.044 (100%, [M+Na]+, calc
640.049), 656.018 (60%, [M+K]+, calc 656.022), 618.062 (20%,
[M+H]+, calc 618.067), 1255.097 (8%, [2 M+Na]+, calc 1255.106),
(21%, [2 M+Na]+, calc 745.308). IR:
1580 (s) cmꢀ1
m(P@N) 1322 (vs), m(C@O)
.
1197.140 (4%, [2 MꢀCl]+, calc 1197.149). IR:
m(P@N) 1340 (vs),
O
m
(C@O) 1532 (s) cmꢀ1
.
3
7
P
N
C
CH3
4
2
1
4.6. Preparation of AuCl2(2-C6H4C(O)N@PPh3) 14
3
6
5
3
ClHg(2-C6H4C(O)N@PPh3) 13 (0.100 g, 0.16 mmol), [Me4-
N][AuCl4] (0.067 g, 0.16 mmol) and [Me4N]Cl (0.018 g, 0.17 mmol)
were stirred in acetonitrile (10 mL) for 2 d in a foil-covered flask.
The solvent was removed under reduced pressure and the yellow
solid extracted into dichloromethane (3 ꢃ 10 mL) and filtered.
The yellow solution was reduced in volume (ꢂ5 mL) and subse-
quent addition of diethyl ether and storage at ꢀ20 °C gave pale yel-
low crystals of AuCl2(2-C6H4C(O)N@PPh3) as the dichloromethane
solvate (0.065 g, 62%). Anal. Calc. for C25H19NOPCl2Au ꢁ CH2Cl2: C,
42.6; H, 2.9; N, 1.9. Found: C, 42.7; H, 2.9; N, 1.9%. NMR (see
Scheme 4 for the labelling system): 1H d 7.29 (d, 1H, H-6), 7.37
(m, 1H, H-4), 7.40 (m, 1H, H-5), 7.58 (m, 6H, H-10), 7.69 (m, 3H,
H-11), 7.95 (m, 6H, H-9), 8.10 (d, 1H, H-3); 13C{1H} d 124.0 (d,
NMR labelling scheme for Ph3P=NC(O)But
4.4. Synthesis of (CO)4Mn(2-C6H4C(O)N@PPh3) 12
PhCH2Mn(CO)5 (0.200 g, 0.70 mmol) and Ph3P@NC(O)Ph
(0.268 g, 0.70 mmol) were refluxed in n-heptane (30 mL) for 2 h.
While hot, the solution was filtered and the yellow filtrate reduced
in volume until signs of crystallisation. Storage at ꢀ20 °C gave yel-
low crystals of (CO)4Mn(2-C6H4C(O)N@PPh3) (0.246 g, 65%). Anal.

K.J. Kilpin et al. / Inorganica Chimica Acta 363 (2010) 1021–1030
1029
Table 6
Crystallographic data for the complexes 12, 13, 14 and 17.
Complex
12
13
14.CH2Cl2
17
Formula
Molecular weight
T (K)
C29H19MnNO5P
547.36
89
C25H19NOPClHg
616.42
89
C26H21NOPCl4Au
733.17
89
C25H19NOPCl2Au
648.25
93
Crystal system
Space group
a (Å)
b (Å)
c (Å)
monoclinic
P21/n
14.2665(1)
10.7250(1)
16.7856(2)
90
98.732(1)
90
2538.57(4)
4
triclinic
P1
monoclinic
P21/n
10.4176(3)
17.6738(4)
15.0557(5)
90
110.231(2)
90
2601.02(13)
4
tetragonal
I4
21.4348(6)
21.4348(6)
9.7613(3)
90
90
90
4484.8(2)
8
1.920
ꢀ
ꢀ
8.7828(3)
10.6870(3)
12.5133(4)
105.335(1)
104.864(1)
90.765(2)
1090.64(6)
2
a
(°)
b (°)
c
(°)
V (Å3)
Z
Dcalc (g cmꢀ3
Tmax,min
)
1.432
0.9014, 0.8160
6186
1.877
0.5301, 0.3545
5239
1.872
0.6390, 0.5257
6087
0.3396, 0.1159
8411
Number of unique reflections
Number of observed reflections [I > 2
r
(I)]
5427
4927
4985
8021
R[I > 2
wR2 (all data)
Goodness of fit (GOF)
Flack x parameter
r
(I)]
0.0302
0.0822
1.038
0.0171
0.0422
1.077
–
0.0252
0.0503
0.996
0.0193
0.0401
1.011
–
–
0.017(3)
3
1JPC 103.3 Hz, C-8), 128.5 (C-6), 129.2 (d, JPC 13.6 Hz, C-10), 130.1
4.10. X-ray crystal structure determinations
4
(C-3), 130.3 (C-5 and C-2), 133.6 (C-4), 133.8 (d, JPC 2.6 Hz, C-11),
2
2
133.9 (d, JPC 10.6 Hz, C-9), 144.9 (C-1), 179,5 (d, JPC 3.9 Hz, C-7);
Crystals of 13 and 14 were grown by adding diethyl ether to a
dichloromethane solution of the compound and storing at
ꢀ20 °C, while single crystals of 12 and 17 were grown by vapour
diffusion of diethyl ether into a dichloromethane solution of the
compound at room temperature. Crystallographic details are pre-
sented in Table 6.
31P{1H} d 35.8 ppm. ESI-MS: m/z: 612.059 (100%, [MꢀCl]+, calc
612.055). IR: m(P@N) 1285 (vs), m .
(C@O) 1684 (s) cmꢀ1
4.7. Preparation of Hg(2-C6H4P(@NC(O)Ph)Ph2)2 16
To a degassed solution of PhC(O)N3 (0.081 g, 0.55 mmol) in dry
dichloromethane (10 mL), Hg(2-C6H4PPh2)2 15 (0.200 g, 0.28
mmol) was added and the resulting mixture was stirred at room
temperature under nitrogen for 24 h. The solution was reduced
in volume and diethyl ether was added until signs of crystallisa-
tion. Storage at ꢀ20 °C gave white microcrystals of Hg(2-
C6H4P(@NC(O)Ph)Ph2)2 (0.207 g, 77%). Anal. Calc. for C50H38P2-
N2O2Hg: C, 62.5; H, 4.0; N, 2.9. Found: C, 62.2; H, 4.1; N, 2.8%.
NMR: 1H d 7.09 (m, 3H), 7.22 (m, 4H), 7.40 (m, 4H), 7.51 (m, 2H),
7.72 (m, 4H), 8.12 (d, 2H); 31P{1H} d 27.4 (3JHgP 171 Hz) ppm. ESI-
MS: m/z: 985.205 (100%, [M+Na]+, calc 985.202), 963.224 (21%,
4.10.1. Data collection
Unit cell dimensions and intensity data were collected at either
the University of Canterbury on a Bruker Nonius Apex II CCD dif-
fractometer (17) or the University of Auckland on a Bruker Smart
CCD diffractometer (12, 13 and 14). Absorption correction of the
data was carried out by semi-empirical methods (SADABS) [35].
4.10.2. Solution and refinement
Structures were solved by either the direct methods (12) or the
Patterson options of SHELXS-97 [36] and were developed routinely.
Full-matrix least-squares refinement (SHELXL-97) [37] was based
upon F2o with all non-hydrogen atoms refined anisotropically and
hydrogen atoms in calculated positions.
[M+H]+, calc 963.220). IR:
m(P@N) 1323 (vs), m .
(C@O) 1598 (s) cmꢀ1
4.8. Preparation of AuCl2(2-C6H4Ph2P@NC(O)Ph) 17
Hg(2-C6H4P(@NC(O)Ph)Ph2)2 16 (0.100 g, 0.10 mmol), [Me4-
N][AuCl4] (0.086 g, 0.21 mmol) and [Me4N]Cl (0.011 g, 0.10 mmol)
were stirred in acetonitrile (10 mL) for 7 d in a foil-covered flask.
Work-up as for 14 gave yellow microcrystals (0.091 g, 68%).
NMR: 1H d 7.18 (m, 1H), 7.41 (m, 3H), 7.51 (m, 2H), 7.60 (m, 4H),
7.72 (m, 2H), 7.88 (m, 4H), 8.01 (d, 2H), 8.26 (d, 1H); 31P{1H} d
60.5 ppm. ESI-MS: m/z: 612.052 (100%, [MꢀCl]+, calc 612.055),
1319 (36%, [2 M+Na]+, calc 1319.037), 670.013 (16%, [M+Na]+, calc
Acknowledgements
We thank The University of Waikato for financial support of this
work, including technical support from Wendy Jackson and Pat
Gread, and Prof. Alistair Wilkins for assistance with NMR spectros-
copy. KJK thanks The Tertiary Education Commission (Top Achiev-
ers Doctoral Scholarship) and the New Zealand Federation of
Graduate Women (Merit Award for Doctoral Study). Dr. Jan Wika-
ira (University of Canterbury) and Dr. Tania Groutso (University of
Auckland) are thanked for collection of the X-ray data sets.
670.020). IR:
m(P@N) 1282 (vs), m .
(C@O) 1641 (vs) cmꢀ1
4.9. Attempted cyclomanganation of Ph3P@NC(O)But
Following a similar procedure for the synthesis of 12, the at-
tempted reaction of Ph3P@NC(O)But and PhCH2Mn(CO)5 was mon-
itored by IR spectroscopy and thin layer chromatography; after
refluxing for 8 h only unreacted PhCH2Mn(CO)5 was observed, to-
gether with some brown insoluble matter that is typically associ-
ated with slow thermal decomposition of refluxing solutions of
PhCH2Mn(CO)5.
Appendix A. Supplementary material
CCDC 746296, 746299, 746297 and 746298 contains the sup-
plementary crystallographic data for complexes 12, 13, 14 and
17, respectively. These data can be obtained free of charge from
The Cambridge Crystallographic Data Centre via http://www.ccdc.
cam.ac.uk/data_request/cif. Supplementary data associated with

1030
K.J. Kilpin et al. / Inorganica Chimica Acta 363 (2010) 1021–1030
[18] H. Morita, A. Tatami, T. Maeda, B.J. Kim, W. Kawashima, T. Yoshimura, H. Abe,
T. Akasaka, J. Org. Chem. 73 (2008) 7159.
[19] J. Vicente, J.-A. Abad, R. Clemente, J. López-Serrano, M.C. Ramírez de Arellano,
P.G. Jones, D. Bautista, Organometallics 22 (2003) 4248.
[20] J.M. Cooney, L.H.P. Gommans, L. Main, B.K. Nicholson, J. Organomet. Chem. 336
(1987) 293.
this article can be found, in the online version, at doi:10.1016/
j.ica.2009.12.019.
References
[21] M.A. Leeson, B.K. Nicholson, M.R. Olsen, J. Organomet. Chem. 579 (1999) 243.
[22] P.E. Garrou, Chem. Rev. 81 (1981) 229.
[1] H.J. Bestmann, R. Zimmerman, Phosphine alkylenes and other phosphorus
ylides, Organic Phosphorus Compounds, vol. 3, Wiley Interscience, 1972, p. 1.
[2] A.W. Johnson, Ylides and Imines of Phosphorus, Wiley, New York, 1993.
[3] I. Omae, Coord. Chem. Rev. 248 (2004) 995.
[4] W. Henderson, Adv. Organomet. Chem. 54 (2006) 207.
[5] K.J. Kilpin, W. Henderson, B.K. Nicholson, Dalton Trans. (2010), doi:10.1039/
B916755B.
[6] P. Oña-Burgos, I. Fernández, L. Roces, L.T. Fernández, S. García-Granda, F.L.
Ortiz, Organometallics 28 (2009) 1739.
[7] S.D.J. Brown, W. Henderson, K.J. Kilpin, B.K. Nicholson, Inorg. Chim. Acta 360
(2007) 1310.
[8] K.J. Kilpin, W. Henderson, B.K. Nicholson, Inorg. Chim. Acta 362 (2009) 3669.
[9] D. Aguilar, M. Contel, R. Navarro, E.P. Urriolabeitia, Organometallics 26 (2007)
4604.
[10] N. Shaik, A. Martínez, I. Augustin, H. Giovinazzo, A. Varela-Ramírez, M. Sanaú,
R.J. Aguilera, M. Contel, Inorg. Chem. 48 (2009) 1577.
[11] D. Aguilar, M. Contel, R. Navarro, T. Soler, E.P. Urriolabeitia, J. Organomet.
Chem. 694 (2009) 486.
[23] N.P. Robinson, L. Main, B.K. Nicholson, J. Organomet. Chem. 349 (1988) 209.
[24] L. Main, B.K. Nicholson, Adv. Metal Org. Chem. 3 (1994) 1.
[25] I. Bar, J. Bernstein, Acta Crystallogr., Sect. B 36 (1980) 1962.
[26] J. Vicente, M.-D. Bermúdez, F.-J. Carrión, P.G. Jones, Chem. Ber. 129 (1996)
1395.
[27] J. Vicente, M.T. Chicote, A. Arcas, M. Artigao, R. Jiménez, J. Organomet. Chem.
247 (1983) 123.
[28] See for example: P.A. Bonnardel, R.V. Parish, R.G. Pritchard, J. Chem. Soc.,
Dalton Trans. (1996) 3185.
[29] M.A. Bennett, M. Contel, D.C.R. Hockless, L.L. Welling, A.C. Willis, Inorg. Chem.
41 (2002) 844.
[30] M.A. Bennett, M. Contel, D.C.R. Hockless, L.L. Welling, Chem. Commun. (1998)
2401.
[31] P. Zuohua, W. Xincheng, S. Meicheng, W. Yangjie, C. Zhendrong, W. Yulan, H.
Hongwen, Acta Chim. Sin. 43 (1985) 801. CCDC refcode: DONKUM.
[32] S. Bräse, C. Gil, K. Knepper, V. Zimmermann, Angew. Chem., Int. Ed. Engl. 44
(2005) 5188.
[33] K.J. Kilpin, W. Henderson, B.K. Nicholson, Dalton Trans. (2008) 3899.
[34] D.F. Shriver, M.A. Drezdzon, The Manipulation of Air-Sensitive Compounds,
Wiley, New York, 1986.
[12] D. Aguilar, M.A. Aragüés, R. Bielsa, E. Serrano, R. Navarro, E.P. Urriolabeitia,
Organometallics 26 (2007) 3541.
[13] D. Aguilar, R. Bielsa, M.A. Contel, A. Lledos, R. Navarro, T. Soler, E.P.
´
Urriolabeitia, Organometallics 27 (2008) 2929.
[35] R.H. Blessing, Acta Crystallogr., Sect. A 51 (1995) 33.
[36] G.M. Sheldrick, SHELXS-97 – A Program for the Solution of Crystal Structures,
University of Göttingen, Germany, 1997.
[37] G.M. Sheldrick, SHELXL-97 – A Program for the Refinement of Crystal Structures,
University of Göttingen, Germany, 1997.
[14] R. Bielsa, R. Navarro, T. Soler, E.P. Urriolabeitia, Dalton Trans. (2008) 1787.
[15] R. Bielsa, A. Larrea, R. Navarro, T. Soler, E.P. Urriolabeitia, Eur. J. Inorg. Chem.
(2005) 1724.
[16] A.R. Katritzky, N.M. Khasab, S. Bobrov, Helv. Chim. Acta 88 (2005) 1664.
[17] P. Frøyen, Phosphorus, Sulfur and Silicon 78 (1993) 161.