4-Diphenylphosphinosydnone imines as bidentate ligands

Article abstract of DOI:10.1016/j.poly.2009.04.038

The synthesis and characterization of new 3-substituted-4-diphenylphosphinosydnone imines (1,2,3-oxadiazolium-imines-5) are reported. {A figure is presented}. These compounds react with [PdCl₂(MeCN)₂] in MeCN to afford monomeric cis-

Full text of DOI:10.1016/j.poly.2009.04.038

Polyhedron 28 (2009) 2411–2417
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4-Diphenylphosphinosydnone imines as bidentate ligands
a
a
a
Valeriy N. Kalinin a, , Sergey N. Lebedev , Il’ia A. Cherepanov , Ivan A. Godovikov ,
*
Konstantin A. Lyssenko a, Evamarie Hey-Hawkins b
a A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov Str. 28, Moscow 119991, Russian Federation
b Department of Inorganic Chemistry, Universitat Leipzig, Johannisallee 29, D-04103 Leipzig, Germany
a r t i c l e i n f o
a b s t r a c t
Article history:
The synthesis and characterization of new 3-substituted-4-diphenylphosphinosydnone imines (1,2,3-
oxadiazolium-imines-5) are reported.
Received 31 March 2009
Accepted 16 April 2009
Available online 7 May 2009
R
PPh2
3
4
N
Keywords:
Sydnone imines
Mesoionic heterocycles
P,N-donor bidentate ligands
Palladium complexes
Crystal structure
( R= nBu, NMe2 ; R'= Me, tBu, Ph, CF3 )
5
+
2
N
-
6
NCOR'
O
1
These compounds react with [PdCl2(MeCN)2] in MeCN to afford monomeric cis-P,N-coordinated palla-
dium complexes.
Ó 2009 Elsevier Ltd. All rights reserved.
1. Introduction
those of the oxygen atom in sydnones. Sydnone imines, in contrast
to sydnones, form salts with strong acids. The pKa values for syd-
The synthesis and application of phosphorus ligands, especially
for the cases where the phosphorus ligand contains another coor-
dinating functionality, are of considerable interest [1]. By introduc-
ing the second donor atom (N, S, O, Se, As, P) into the ligand it is
possible to obtain bidentate ligands with donor centers of different
donor capability and steric properties. The use of a heterocyclic
moiety as a part of the ligand system has attracted great attention
in recent years. In this paper we report the synthesis of new type of
bidentate ligand containing a mesoionic moiety.
none imines 4 vary from 2.5 to 4.6, depending on the substituents
[4,5]. In addition, sydnone imines 4 react with methyl iodide to give
the quaternary ammonium salt of the exocyclic nitrogen [5,6].
4-Phosphino substituted derivatives of sydnone imines, 5 in
Fig. 1, should be more prone to act as bidentate ligands than their
sydnone analogues (1 in Scheme 1). Thus, coordination of 5 to tran-
sition metals could give rise to chelated complexes, 6 in Fig. 1.
2. Results and discussion
The first attempt to prepare such complexes based on sydnones
was described in [2]. 4-Phosphino derivatives of sydnones, 1, were
chosen as the subject of the investigation. It was suggested by the
authors that the exocyclic oxygen atom, bearing a negative charge,
of the sydnone ring can act as a second donor center. However, the
reaction of 3-(4-methoxyphenyl)-4-(ditertbutylphosphino)-syd-
none 1 (R = –OMe) with PdCl2 in EtOH gave the cyclometallation
product, 2. The cyclometallation process does not occur in the ab-
sence of a donor substituent at the 3 position of the phenyl group
(Scheme 1). In this case, only the formation of the bis(phosphine)
complex 3 is observed.
2.1. Synthesis of 4-diphenylphosphinosydnone imines
To synthesize new 4-diphenylphosphino derivatives of the syd-
none imines 5 we have used the reaction of 4-lithium derivatives
of sydnone imines [7] with diphenylphosphine chloride (Scheme
2, Table 1). Both the lithiation of sydnone imines and the addition
of Ph2PCl were carried out at the temperatures below ꢀ90 °C. At
higher temperatures the formation of large amounts of decomposi-
tion products was observed, especially at the lithiation stage. Fur-
thermore, both n-BuLi and Ph2PCl must be slowly added to the
reaction mixture to avoid overheating of the solution.
Sydnone imines, 4 in Fig. 1, are nitrogen analogues of sydnones
and their exocyclic nitrogen atom also bears a significant negative
charge [3]. However, the electron donating properties of the exocy-
clic nitrogen atom in sydnone imines are substantially stronger than
The 3-substituted-4-diphenylphosphinosydnone imines ob-
tained belong to the class of hemilabile ligands, which contain both
soft and hard donor atoms. The
phorus atom can stabilize a metal center in a low oxidation state,
while the -donor ability of the nitrogen atom makes the metal
atom more susceptible to oxidative addition reactions.
p-acceptor character of the phos-
p
* Corresponding author. Tel.: +7 499 135 9314.
E-mail address: vkalin@ineos.ac.ru (V.N. Kalinin).
0277-5387/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2009.04.038

2412
V.N. Kalinin et al. / Polyhedron 28 (2009) 2411–2417
O
Cl
Pd
N
+
P
tBu
tBu
N
R
R = OMe
O
-
R
O
2
P(tBu)2
2
N
tBu tBu
P
PdCl2/HCl
EtOH
Cl
Pd
-
+
O
N
O
N
Cl
-
+
O
N
O
1
R = H
O
+
-
N
O
tBu
P
Cl
Pd
Cl
tBu
N
P
tBu
tBu
N
-
+
O
N
O
3
Scheme 1.
R"
R"
R"
R"
R
PPh2
R
PPh2
R
R
R''
R
P
P
N
N
PdCl2
N
N
MLn
i
N
+
O
+
O
-
-
+
O
-
+
O
N
N
+
O
-
-
N
N
N
N
N
N
N
N
COR'
COR'
COR'
COR'
COR'
4
6
5
5a-f
6a-f
Fig. 1. Starting materials, ligands and target complexes.
Scheme 3. (i) [PdCl2(MeCN)2], MeCN.
R
R
PPh2
N
N
i, ii
+
O
+
O
N
N
-
-
N
N
COR1
COR1
5a-f
4a-f
Scheme 2. (i) 1 equiv. n-BuLi, THF, ꢀ90 °C and (ii) 1 equiv. Ph2PCl, ꢀ90 °C ? r.t
(slowly).
Table 1
Synthesis of 3-substituted-4-diphenylphosphinosydnone imines.
Compound
R
R1
Yield, %
5a
5b
5c
5d
5e
5f
n-Bu
n-Bu
n-Bu
n-Bu
Me2N
Me2N
Me
Ph
CF3
t-Bu
Me
Ph
67
80
56
86
75
70
2.2. Bidentate coordination chemistry of 3-substituted-4-
diphenylphosphinosydnone imines
Fig. 2. General view of compound 6a, atoms represented by 50% thermal ellipsoids.
Treatment of the 4-diphenylphosphinosydnone imine 5a with
[PdCl2(MeCN)2] in MeCN resulted in the formation of only one
product, 6a (Scheme 3). According to the X-ray structural data of
complex 6a, the ligand coordinates with palladium by P(1) and
N(6) atoms forming the five-membered metallocycle (Fig. 2).

V.N. Kalinin et al. / Polyhedron 28 (2009) 2411–2417
2413
Table 2
Table 3
Synthesis of palladium complexes of 3-substituted-4-diphenylphosphinosydnone
imines.
Selected bond lengths (Å) and angles (°) for the compounds 6a, 6e and 5e.
Parameter
6a
6e
5e
Compound
R
R1
Yield,%
Bond lengths
Pd(1)–Cl(1)
Pd(1)–Cl(2)
Pd(1)–P(1)
Pd(1)–N(6)
P(1)–C(4)
O(1)–N(2)
O(1)–C(5)
N(2)–N(3)
N(3)–C(4)
C(4)–C(5)
C(5)–N(6)
N(6)–C(6)
N(3)–N(8)
6a
6b
6c
6d
6e
6f
n-Bu
n-Bu
n-Bu
n-Bu
Me2N
Me2N
Me
Ph
CF3
t-Bu
Me
Ph
90
85
53
85
83
95
2.361(1)
2.286(1)
2.232(1)
2.096(3)
1.796(4)
1.395(4)
1.364(4)
1.295(5)
1.356(5)
1.391(5)
1.323(5)
1.414(5)
2.351(1)
2.282(1)
2.224(1)
2.104(4)
1.785(5)
1.390(5)
1.366(6)
1.301(6)
1.337(6)
1.394(6)
1.310(6)
1.435(6)
1.428(5)
1.811(2)
1.382(2)
1.391(2)
1.300(2)
1.349(2)
1.409(2)
1.296(2)
1.380(2)
1.410(2)
Bond angles
P(1)–Pd(1)–N(6)
Cl(1)–Pd(1)–Cl(2)
N(2)–O(1)–C(5)
O(1)–N(2)–N(3)
N(2)–N(3)–C(4)
N(3)–C(4)–C(5)
C(4)–C(5)–O(1)
87.1(1)
88.5(1)
92.16(5)
109.2(3)
104.9(3)
114.2(3)
104.9(3)
106.8(3)
91.84(5)
109.3(3)
103.7(3)
116.1(4)
103.6(4)
107.2(4)
110.2(1)
103.4(1)
116.8(1)
103.5(1)
105.9(1)
Fig. 3. General view of the complex 6e, atoms represented by 50% thermal
ellipsoids.
Very similar results were obtained in the case of phosphines
5b–f (Scheme 3, Table 2).
The electron donating ability of N(6) in 5 is high. Even the pres-
ence of such electron-withdrawing groups as trifluoroacetyl (5c)
does not prevent the formation of the chelate complex with palla-
dium, although the yield of the product is low.
It should be noted that for compounds 5e and 5f, the dimethyl-
amino group could provide an alternative coordination site. Never-
theless, the X-ray study of 6e shows that the reactions of these
compounds with [PdCl2(MeCN)2] in MeCN give rise only to com-
plexes in which the ligand acts as a bidentant ligand bound to pal-
ladium by the P(1) and N(6) atoms. (Fig. 3).
Fig. 4. The fragment of crystal packing illustrating the interaction of complex 6e
with acetonitrile molecules.
Despite the certain differences in the geometry of the ligands,
the geometrical parameters of the two complexes 6a and 6e are
similar (see Table 3). In both complexes the coordination of palla-
dium is close to planar, with a slight tetrahedral distortion. The an-
gles between the planes Pd(1)P(1)N(6) and Pd(1)Cl(1)Cl(2) are
equal to 3.0(1)° and 8.5(1)° in 6a and 6e, respectively. The bite an-
gles N(6)Pd(1)P(1) in both complexes are almost equal (87.13(9)°
and 88.5(1)°). The five-membered metallocycles in 6a and 6e are
characterized by an envelope conformation, with a deviation of
the Pd(1) atom from the plane C(4)C(5)P(1)N(6) of 0.54 Å in 6a
and 0.32 Å in 6e. In turn, the angles of bend along the P(1)ꢁ ꢁ ꢁN(6)
line in the complexes 6a and 6e are 20.5° and 12.2°. Despite the
different substituents at N(3), the bond lengths of the metallocy-
cles in 6a and 6e are almost the same. Comparing the geometrical
parameters of the sydnone imine ring, one can conclude that the
introduction of the Me2N group leads to a slight shortening of
the N(3)–C(4) bond, considerable shortening of the C(5)–N(6)
and an increase of the N(6)–C(6) bond length.
It should be mentioned that two solvate acetonitrile molecules
in the crystal of 6e are assembled into a dimer via the shortened
C(1S)ꢁ ꢁ ꢁC(3S) (3.344(3) Å) and N(2S)ꢁ ꢁ ꢁH(3S) (2.51 Å) contacts
(Fig. 4). In addition to the above contacts, one of the acetonitrile
molecules participates in rather rare Nꢁ ꢁ ꢁ
p binding with the meso-
ionic cycle, with a shortening of the N(2S)ꢁ ꢁ ꢁC(4) and N(2S)ꢁ ꢁ ꢁC(5)
distances to 3.114(4) and 3.128(4) Å, respectively.
In order to analyze the influence of the complex formation on
the distribution of bond lengths in the mesoionic moiety, we also
performed an X-ray diffraction study of 5e (Fig. 5). A comparison
of the geometries of the free ligand 5e and its complex 6e shows
that the coordination of N(6) to palladium causes the conjugation

2414
V.N. Kalinin et al. / Polyhedron 28 (2009) 2411–2417
Table 4
31P{1H} NMR parameters for the compounds 5a–f and 6a–f.
Compound
Chemical shifts (ppm)
Chemical shifts (ppm)
for compounds 5a–f
for compounds 6a–f
a
b
c
d
e
f
ꢀ35.91
ꢀ35.89
ꢀ35.84
ꢀ36.26
ꢀ35.83
ꢀ35.81
ꢀ7.44
ꢀ15.50
13.48
10.07
ꢀ5.85
ꢀ5.77
and coordinate to a palladium atom by the phosphorus and exocyl-
ic nitrogen N(6) atoms. The charge distribution in the mesoinic
fragment was analyzed by DFT calculations, while the peculiarities
of the geometries for the complexes were investigated by means of
X-ray diffraction analysis. The presence of such a zwitterionic
group as sydnone imine, which is unusual for palladium com-
plexes, can provide them with rather unusual catalytic properties.
3. Experimental
3.1. General
Fig. 5. General view of compound 5e, atoms represented by 50% thermal ellipsoids.
Unless otherwise indicated, all the reactions were performed in a
dry argon atmosphere. The starting sydnone imines 4a–b [10], 4c
[11], 4d [12], 4e [13] and 4f [6] were prepared according to the
described procedures. All commercially available reagents were
used without further purification. IR spectra were recorded from
KBr pellets in the range 4000–400 cmꢀ1 on a Nicolet Magna-IR
750 FT-IR spectrophotometer. 1H NMR spectra were recorded on a
Bruker Avance-400 spectrometer operating at a frequency of
400.13 MHz. 31P NMR spectra were recorded on a Bruker Avance-
400 spectrometer operating at a frequency of 161.98 MHz. Elemen-
tal analyses for C, H and N were performed on a Carlo Erba Elemental
Analyzer – 1106 automatic analyzer. Melting points were deter-
mined with an electrically heated Gallenkamp apparatus.
of the N(6) atom with the p-system of the mesoionic ring and C@O
group to decrease. As a result, the O(1)–C(5) bond in 5e is consid-
erably longer and the C(5) atom of the cycle deviates from the
O(1)N(2)N(3)C(4) plane by 0.06 Å.
An analysis of IR spectra of the free ligands and the correspond-
ing palladium complexes shows that the coordination of the mes-
oionic fragment by palladium atom gives no significant variation of
the vibration spectrum character. The characteristic C@O and C@N
bond vibrations of the mesoionic fragment are slightly blue shifted
by 10–20 cmꢀ1
.
The character of the chemical bonding in the mesoionic cycle, as
well as the conjugation with the amide group, has been analyzed
on the basis of a DFT calculation (m052x/6-311G(d,p)) of the mol-
ecule 5a [8]. The obtained geometry is rather close to those ob-
served in the complexes 6a and 5e. In particular, the C(5)–N(6)
and C(6)–N(6) bond lengths are equal to 1.288 and 1.396 Å. An
examination of the chemical bonding in 5a has been performed
within the ‘‘Atoms in Molecules” theory [9]. First of all, it should
be noted that the charges obtained by integration over the atomic
basins indicate that the most negative value is observed for the
N(6) atom (ꢀ1.17 e). For comparison, the charge of the N(3) atom
is significantly lower than those of the N(6) and N(8) atoms, which
are ꢀ0.4 and ꢀ0.62 e. The total charge of the mesoionic cycle is
3.2. Preparations
3.2.1. N6-acetyl-3-butyl-4-diphenylphosphinosidnonimine (5a)
To a solution of N6-acetyl-3-butylsidnonimine (0.5 g, 2.73
mmol) in THF (50 ml) at ꢀ90 °C, a 1.6 M solution of n-BuLi in hex-
ane (1.9 ml, 3.00 mmol) was added. The solution was stirred for
10 min at the same temperature. Then chlorodiphenylphosphine
(0.55 g, 3.13 mmol) was added. Reaction mixture was stirred for
10 min at the same temperature and then it was heated to room
temperature. The solvent was removed under reduced pressure
and the residue was dissolved in ethyl acetate, filtered through a
layer of Al2O3 (2 ꢂ 3 cm) and washed away with ethyl acetate.
The solvent was removed under reduced pressure and the residue
was crystallized from a mixture of ether and hexane. Yield: 0.67 g
(67%). M.p. 94–95 °C. Anal. Calc. for C20H22N3O2P (367.39): C,
65.39; H, 6.04; N, 11.44. Found: C, 65.20; H, 6.50; N, 11.83%. IR data
(KBr-pellet, cmꢀ1): 2960w, 2780w, 1660s, 1570vs, 1430m, 1250w,
1090m, 999m, 815w, 747w, 528m. 1H NMR (DMSO-d6): d 0.76–
0.80 (m, 3H, CH3CH2CH2CH2), 1.12–1.28 (m, 2H, CH3CH2CH2CH2),
1.81–1.87 (m, 2H, CH3CH2CH2CH2), 1.95 (s, 3H, COCH3), 4.75–
4.79 (m, 2H, CH3CH2CH2CH2), 7.28–7.45 (m, 6H, p-C6H5 + m-C6H5),
7.50–7.54 (m, 4H, o-C6H5). 31P{1H} NMR (DMSO-d6): d ꢀ35.91 (s).
close to zero (ꢀ0.02 e). According to the ellipticity values (
e) (the
ratio of the Hessian eigenvalues in the critical points of the corre-
sponding bonds), the mesoionic cycle is characterized by a signifi-
cant contribution of p-character. Indeed, the maximum value of e
is observed for the N(2)–N(3) bond (0.41), while the minimum
one – for the C(5)–O(1) bond (0.29). Both bonds formed by the
N(6) atom are also characterized by substantial contributions of
the
p-component, with the ellipticity values being 0.20 and 0.30
for the N(6)–C(5) and N(6)–C(6) bonds, respectively.
The 31P{1H} NMR spectra of the obtained complexes show the
variation of the chemical shift of the phosphorus atom (Table 4)
upon complex formation.
3.2.2. N6-benzoyl-3-butyl-4-diphenylphosphinosidnonimine (5b)
The title compound was prepared in the same way as compound
5a, starting from 4b (2 g, 8.16 mmol), 5.6 ml of a 1.6 M solution of
n-BuLi in hexane (8.98 mmol) and 1.7 ml of chlorodiphenylphos-
phine (9.38 mmol). Yield 2.8 g (80%). M.p. 107–108 °C. Anal. Calc.
2.2.1. Conclusion
In this work, the first representatives of 4-phosphorus substi-
tuted sydnone imines have been synthesized. It was shown that
that these molecules can serve as hemilabile bidentante ligands

V.N. Kalinin et al. / Polyhedron 28 (2009) 2411–2417
2415
for C25H24N3O2P (429.46): C, 69.92; H, 5.63; N, 9.78. Found: C,
69.32; H, 5.89; N, 9.50%. IR data (KBr-pellet, cmꢀ1): 3052vw,
2959vw, 2874vw, 1635s, 1571vs, 1432m, 1312m, 1240m, 1207m,
1090m, 989s, 814w, 735w, 695m, 533w. 1H NMR (DMSO-d6): d
0.74–0.81 (m, 3H, CH3CH2CH2CH2), 1.11–1.29 (m, 2H, CH3CH2-
CH2CH2), 1.86–1.89 (m, 2H, CH3CH2CH2CH2), 4.84–4.87 (m, 2H,
CH3CH2CH2CH2), 7.19–7.26 (m, 2H, o-(NCOC6H5)), 7.29–7.43 (m,
6H, p-(C6H5)2P + m-(C6H5)2P), 7.45–7.48 (m, 3H, p-(NCOC6H5) +
m-(NCOC6H5)), 7.54–7.62 (m, 4H, o-(C6H5)2P). 31P{1H} NMR
(DMSO-d6): d ꢀ35.89 (s).
(CH3)2N), 7.22–7.27 (m, 2H, o-(NCOC6H5)), 7.33–7.42 (m, 6H, p-
(C6H5)2P + m-(C6H5)2P), 7.57–7.65 (m, 7H, p-(NCOC6H5) + m-(NCO-
C6H5) + o-(C6H5)2P). 31P{1H} NMR (DMSO-d6): d ꢀ35.81 (s).
3.2.7. N6-acetyl-3-butyl-4-diphenylphosphinosidnonimine palladium
dichloride (6a)
To a solution of N6-acetyl-3-butyl-4-diphenylphosphinosid-
nonimine 5a (0.5 g, 1.36 mmol) in CH3CN (10 ml), [PdCl2(MeCN)2]
(0.35 g, 1.36 mmol) was added. The solution was stirred for 30 min
at room temperature. The solvent was removed under reduced
pressure and the residue was crystallized from a mixture of CH3CN
and ether. Yield: 0.67 g (90%). M.p. 214 °C (dec.). Anal. Calc. for
C20H22Cl2N3O2PPd (544.71): C, 44.10; H, 4.07; N, 7.71. Found: C,
44.29; H, 4.52; N, 7.13%. IR data (KBr-pellet, cmꢀ1): 3052w,
2964w, 2900w, 1671s, 1585vs, 1422m, 1377w, 1265w, 1080m,
1002m, 837w, 768w, 540w. 1H NMR (DMSO-d6): d 0.57–0.60 (m,
3H, CH3CH2CH2CH2), 1.00–1.07 (m, 2H, CH3CH2CH2CH2), 1.26–
1.29 (m, 2H, CH3CH2CH2CH2), 2.47 (s, 3H, COCH3), 4.16–4.20 (m,
2H, CH3CH2CH2CH2), 7.63–7.64 (m, 4H, m-C6H5), 7.73–7.76 (m,
2H, p-C6H5) 7.98–8.03 (m, 4H, o-C6H5). 31P{1H} NMR (DMSO-d6):
d ꢀ7.44 (s).
3.2.3. N6-trifluoroacetyl-3-butyl-4-diphenylphosphinosidnonimine
(5c)
The title compound was prepared in the same way as com-
pound 5a starting from 4c (0.7 g, 2.95 mmol), 2.1 ml of a 1.6 M
solution of n-BuLi in hexane (3.39 mmol) and 0.63 ml of chlorodi-
phenylphosphine (3.54 mmol). Yield 0.7 g (56%). M.p. 125–126 °C.
Anal. Calc. for C20H19F3N3O2P (421.36): C, 57.01; H, 4.55; N, 9.97.
Found: C, 57.25; H, 5.01; N, 9.21%. IR data (KBr-pellet, cmꢀ1):
3052vw, 2963vw, 2874vw, 1653s, 1568vs, 1435w, 1202m, 1165s,
1132m, 1017m, 866w, 747w, 696w. 1H NMR (DMSO-d6): d 0.77–
0.81 (m, 3H, CH3CH2CH2CH2), 1.24–1.30 (m, 2H, CH3CH2CH2CH2),
1.84–1.91 (m, 2H, CH3CH2CH2CH2), 4.88–4.91 (m, 2H, CH3CH2-
CH2CH2), 7.33–7.41 (m, 6H, p-C6H5 + m-C6H5), 7.52–7.56 (m, 4H,
o-C6H5). 31P{1H} NMR (DMSO-d6): d ꢀ35.84 (s).
3.2.8. N6-benzoyl-3-butyl-4-diphenylphosphinosidnonimine
palladium dichloride (6b)
The title compound was prepared in the same way as compound
6a starting from 5b (0.2 g, 0.475 mmol) and [PdCl2(MeCN)2] (0.12 g,
0.475 mmol). Yield 0.25 g (85%). M.p. 194 °C (dec.). Anal. Calc. for
C25H24Cl2N3O2PPd (606.78): C, 49.49; H, 3.99; N, 6.93. Found: C,
49.10; H, 4.20; N, 6.55%. IR data (KBr-pellet, cmꢀ1): 3059vw,
2963vw, 2874vw, 1656s, 1568vs, 1431m, 1257m, 1169vw, 1098w,
1013m, 747w, 688m. 1H NMR (DMSO-d6): d 0.63–0.75 (m, 3H,
CH3CH2CH2CH2), 1.05–1.16 (m, 2H, CH3CH2CH2CH2), 1.50–1.63 (m,
2H, CH3CH2CH2CH2), 4.05–4.18 (m, 2H, CH3CH2CH2CH2), 7.18–7.25
(m, 2H, o-(NCOC6H5)), 7.29–7.43 (m, 3H, p-(NCOC6H5) + m-(N-
COC6H5)), 7.52–7.65 (m, 6H, p-(C6H5)2P + m-(C6H5)2P), 8.04–8.21
(m, 4H, o-(C6H5)2P). 31P{1H} NMR (DMSO-d6): d ꢀ15.50 (s).
3.2.4. N6-trimethylacetyl-3-butyl-4-diphenylphosphinosidnonimine
(5d)
The title compound was prepared in the same way as com-
pound 5a starting from 4d (1.0 g, 4.44 mmol), 3.0 ml of a 1.6 M
solution of n-BuLi in hexane (4.89 mmol) and 0.92 ml of chlorodi-
phenylphosphine (5.10 mmol). Yield 1.56 g (86%). M.p. 104–105 °C.
Anal. Calc. for C23H28N3O2P (409.47): C, 67.47; H, 6.89; N, 10.26.
Found: C, 67.30; H, 7.01; N, 10.63%. IR data (KBr-pellet, cmꢀ1):
3059w, 2956w, 2867w, 1634s, 1601vs, 1579s, 1475w, 1435m,
1383w, 1313w, 1172m, 1109w, 999m, 744w, 692w, 515vw. 1H
NMR (DMSO-d6): d 0.77–0.92 (m, 12H, CH3CH2CH2CH2 + C(CH3)3),
1.20–1.27 (m, 2H, CH3CH2CH2CH2), 1.83–1.91 (m, 2H, CH3CH2-
CH2CH2), 4.80–4.83 (m, 2H, CH3CH2CH2CH2), 7.34–7.36 (m, 6H,
p-C6H5 + m-C6H5), 7.51–7.54 (m, 4H, o-C6H5). 31P{1H} NMR
(DMSO-d6): d ꢀ36.26 (s).
3.2.9. N6-trifluoroacetyl-3-butyl-4-diphenylphosphinosidnonimine
palladium dichloride (6c)
The title compound was prepared in the same way as compound
6a starting from 5c (0.2 g, 0.475 mmol) and [PdCl2(MeCN)2] (0.12 g,
0.475 mmol). Yield 0.15 g (53%). M.p. 190 °C (dec.). Anal. Calc. for
C20H19Cl2F3N3O2PPd (598.68): C, 40.12; H, 3.20; N, 7.02. Found: C,
40.32; H, 3.05; N, 6.89%. IR data (KBr-pellet, cmꢀ1): 3050vw,
2963vw, 2877vw, 1665s, 1571vs, 1440w, 1220m, 1140m, 1120w,
1030m, 869vw, 758w, 675w. 1H NMR (DMSO-d6): d 0.70–0.74 (m,
3H, CH3CH2CH2CH2), 1.11–1.18 (m, 2H, CH3CH2CH2CH2), 1.52–
1.67 (m, 2H, CH3CH2CH2CH2), 4.48–4.57 (m, 2H, CH3CH2CH2CH2),
7.53–7.59 (m, 4H, m-C6H5), 7.63–7.67 (m, 2H, p-C6H5), 8.09–8.17
(m, 4H, o-C6H5). 31P{1H} NMR (DMSO-d6): d 13.48 (s).
3.2.5. N6-acetyl-3-dimethylamino-4-diphenylphosphinosidnonimine
(5e)
The title compound was prepared in the same way as com-
pound 5a starting from 4e (2.5 g, 14.70 mmol), 10.0 ml of a 1.6 M
solution of n-BuLi in hexane (16.20 mmol) and 3.0 ml of chlorodi-
phenylphosphine (16.90 mmol). Yield 3.9 g (75%). M.p. 126–127 °C
Anal. Calc. for C18H19N4O2P (354.35): C, 61.01; H, 5.40; N, 15.81.
Found: C, 60.59; H, 6.00; N, 15.20%. IR data (KBr-pellet, cmꢀ1):
2785w, 2459w, 1671s, 1580vs, 1435s, 1390w, 1265w, 1150m,
1121m, 1032w, 725m, 699m, 555w. 1H NMR (DMSO-d6): d 1.86
(s, 3H, COCH3), 3.07 (s, 6H, (CH3)2N), 7.35–7.37 (m, 6H, m-C6H5 +
p-C6H5), 7.52–7.56 (m, 4H, o-C6H5). 31P{1H} NMR (DMSO-d6): d
ꢀ35.83 (s.).
3.2.10. N6-trimethylacetyl-3-butyl-4-diphenylphosphinosidnonimine
palladium dichloride (6d)
The title compound was prepared in the same way as compound
6a starting from 5d (0.5 g, 1.22 mmol) and [PdCl2(MeCN)2] (0.32 g,
1.22 mmol). Yield 0.61 g (85%). M.p. 204 °C (dec.). Anal. Calc. for
C23H28Cl2N3O2PPd (586.79): C, 47.08; H, 4.81; N, 7.16. Found: C,
46.95; H, 5.11; N, 7.64%. IR data (KBr-pellet, cmꢀ1): 2963w,
2874vw, 1723m, 1619vs, 1568m, 1479w, 1435m, 1095m, 1006m,
751w, 688w, 529m. 1H NMR (DMSO-d6): d 0.69–0.77 (m, 12H,
CH3CH2CH2CH2 + C(CH3)3), 1.11–1.16 (m, 2H, CH3CH2CH2CH2),
1.61–1.68 (m, 2H, CH3CH2CH2CH2), 4.59–4.69 (m, 2H, CH3CH2-
CH2CH2), 7.48–7.65 (m, 6H, p-C6H5 + m-C6H5), 7.95–8.05 (m, 4H,
o-C6H5). 31P{1H} NMR (DMSO-d6): d 10.07 (s.).
3.2.6. N6-benzoyl-3-dimethylamino-4-diphenylphosphinosidnonimine
(5f)
The title compound was prepared in the same way as com-
pound 5a starting from 4f (2.0 g, 8.60 mmol), 5.9 ml of a 1.6 M
solution of n-BuLi in hexane (9.50 mmol) and 1.8 ml of chlorodi-
phenylphosphine (9.90 mmol). Yield 2.5 g (70%). M.p. 123–
124 °C. Anal. Calc. for C23H21N4O2P (416.42): C, 66.34; H, 5.08; N,
13.45. Found: C, 65.99; H, 5.22; N, 13.25%. IR data (KBr-pellet,
cmꢀ1): 3040w, 2878vw, 1620s, 1550vs, 1430m, 1340m, 1255m,
1140w, 1000m, 750w, 532w. 1H NMR (DMSO-d6): d 3.15 (s, 6H,

2416
V.N. Kalinin et al. / Polyhedron 28 (2009) 2411–2417
Table 5
Crystal data and structure refinement parameters for 5e, 6a and 6e.
5e
6a
6e
Formula
Formula weight
T (K)
C18H19N4O2P
354.34
120
C20H22Cl2N3O2PPd
544.68
153
C22H25Cl2N6O2PPd
613.75
153
Crystal system
Space group
Z (Z0)
triclinic
P1
2 (1)
monoclinic
P21/c
4 (1)
monoclinic
P21/n
4 (1)
ꢀ
a (Å)
b (Å)
c (Å)
8.0945(12)
9.6967(15)
11.3273(17)
87.477(3)
83.704(3)
89.965(3)
882.9(2)
1.333
8.6676(17)
14.121(3)
18.115(4)
90.00
97.97(3)
90.00
2195.8(8)
1.648
11.83
10.487(3)
14.694(3)
17.440(5)
90.00
97.02(2)
90.00
2667.3(12)
1.528
9.86
a
(°)
b (°)
c
(°)
V (Å3)
dcalc (g cmꢀ3
l
)
(cmꢀ1
)
1.75
F(0 0 0)
372
1096
1240
2hmax (°)
56
56
50
Reflections collected
Independent reflections
Observed reflections [I > 2
Number of parameters
R1
7805
4184
3183
229
0.0489
0.1210
1.004
0.388/ꢀ0.261
6509
5281
4865
265
0.0549
0.1381
1.092
1.265/ꢀ1.446
4988
4717
3184
316
0.0411
0.1016
0.922
1.395/ꢀ0.976
r
(I)]
wR2
Goodness-of-fit (GOF)
D
q
/
max Dqmin (e Åꢀ3
)
3.2.11. N6-acetyl-3-dimethylamino-4-diphenylphosphinosidnonimine
palladium dichloride (6e)
pancies of 0.78 and 0.22. The positions of the hydrogen atoms
were calculated. Crystal data and structure refinement parameters
for 5e, 6a and 6e are given in Table 5. All calculations were per-
formed using the SHELXTL software [14].
The title compound was prepared in the same way as com-
pound 6a starting from 5e (0.5 g, 1.40 mmol) and [PdCl2(MeCN)2]
(0.37 g, 1.40 mmol). Yield 0.62 g (83%). M.p. 195 °C (dec.). Anal.
Calc. for C18H19Cl2N4O2PPd (531.67): C, 40.66; H, 3.60; N, 13.34.
Found: C, 40.99; H, 3.82; N, 13.11%. IR data (KBr-pellet, cmꢀ1):
3052vw, 2926vw, 1693s, 1579s, 1557vs, 1435s, 1361w, 1213s,
1106m, 999w, 747w, 688m, 526m. 1H NMR (DMSO-d6): d 2.36 (s,
3H, COCH3), 2.80 (s, 6H, (CH3)2N), 7.55–7.62 (m, 4H, m-C6H5),
7.68–7.79 (m, 2H, p-C6H5), 7.98–8.02 (m, 4H, o-C6H5). 31P{1H}
NMR (DMSO-d6): d ꢀ5.85 (s).
Supplementary data
CCDC 723513, 723514, and 723515 contain the supplementary
crystallographic data for 5e, 6a, and 6e. These data can be obtained
free of charge via <http://www.ccdc.cam.ac.uk/conts/retriev-
ing.html>, or from the Cambridge Crystallographic Data Center,
12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-
033; or e-mail: deposit@ccdc.cam.ac.uk.
3.2.12. N6-benzoyl-3-dimethylamino-4-
diphenylphosphinosidnonimine palladium dichloride (6f)
The title compound was prepared in the same way as compound
6a starting from 5f (0.5 g, 1.20 mmol) and [PdCl2(MeCN)2] (0.31 g,
1.20 mmol). Yield 0.68 g (95%). M.p. 189–190 °C (dec.). Anal. Calc.
for C23H21Cl2N4O2PPd (593.75): C, 46.53; H, 3.56; N, 9.44. Found:
C, 46.08; H, 3.28; N, 9.23%. IR data (KBr-pellet, cmꢀ1): 3052vw,
1639s, 1597vs, 1571s, 1446m, 1350w, 1279w, 1246m, 1158w,
1098m, 991m, 751w, 725w, 537w. 1H NMR (DMSO-d6): d 3.20 (s,
6H, (CH3)2N), 7.19–7.26 (m, 2H, o-(NCOC6H5)), 7.28–7.43 (m, 6H,
p-(NCOC6H5) + m-(NCOC6H5)), 7.51–7.66 (m, 6H, p-(C6H5)2P + m-
(C6H5)2P)), 8.05–8.23 (m, 4H, o-(C6H5)2P). 31P{1H} NMR (DMSO-
d6): d ꢀ5.77 (s).
Acknowledgements
Authors thank the Russian Foundation for Basic Research (grant
no. 09-03-00603-a) and the International Science and Technology
Center (grant ISTC G-1361) for financial support.
References
[1] (a) G. Chelucci, G. Orrù, G.A. Pinna, Tetrahedron 59 (2003) 499;
(b) P. Braunstein, J. Organomet. Chem. 689 (2004) 3953;
(c) S.E. Angell, C.W. Rogers, Y. Zhang, M.O. Wolf, W.E. Jones Jr., Coord. Chem.
Rev. 250 (2006) 1829.
[2] (a) L. Shao-Tao, C.H. Sheng, L. Lin-Shun, W. Ju-Chun, Organometallics 16
(1997) 1803;
(b) L. Shao-Tao, C.H. Sheng, L. Lin-Shun, W. Ju-Chun, J. Organomet. Chem. 610
(2000) 1.
[3] (a) C.G. Newton, C.A. Ramsden, Tetrahedron 38 (1982) 2967;
(b) Uspehi Khimii 49 (1980) 64.
4. X-ray diffraction analysis
[4] V.G. Yashunskii, L.E. Holodov, O.I. Samoilova, Chem. Commun. 30 (1965) 4257.
[5] V.G. Yashunskii, O.I. Samoilova, L.E. Holodov, Zur. Obsh. Him. 34 (1964) 2050.
[6] K. Masuda, T. Kamiya, I. Imashira, T. Kaneko, Chem. Pharm. Bull. Jpn. 19 (1971)
72.
Crystals suitable for the X-ray diffraction analysis were ob-
tained by slow evaporation from MeCN solutions. X-ray diffraction
experiments of 5e were carried out with a Bruker SMART 1000 CCD
[7] (a) I.A. Cherepanov, V.N. Kalinin, Mendeleev Commun. (2000) 181;
(b) I.A. Cherepanov, N.V. Egorova, K.B. Martinovich, V.N. Kalinin, Doklady
Chem. 374 (2000) 175.
[8] M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria, M.A. Robb, J.R. Cheeseman,
V.G. Zakrzewski, J.A. Montgomery, R.E. Stratmann, J.C. Burant, S. Dapprich, J.M.
Millam, A.D. Daniels, K.N. Kudin, M.C. Strain, O. Farkas, J. Tomasi, V. Barone, M.
Cossi, R. Cammi, B. Mennucci, C. Pomelli, C. Adamo, S. Clifford, J. Ochterski, G.A.
Petersson, P.Y. Ayala, Q. Cui, K. Morokuma, D.K. Malick, A.D. Rabuck, K.
Raghavachari, J.B. Foresman, J. Cioslowski, J.V. Ortiz, A.G. Baboul, B.B. Stefanov,
diffractometer (Mo K
6a and 6e they were carried out with a Syntex P21 diffractometer
(Mo K ) = 0.71073 Å, -scans) at 153 K. The structures were solved
by the direct method and refined by full-matrix least-squares
against F2 in anisotropic approximation for non-hydrogen atoms.
The analysis of the Fourier density synthesis has revealed a disor-
der of the oxygen atom O(2) in 6e over two positions with occu-
a) = 0.71073 Å, x-scans) at 110 K, while for
a
x

V.N. Kalinin et al. / Polyhedron 28 (2009) 2411–2417
2417
G. Liu, A. Liashenko, P. Piskorz, I. Komaromi, R. Gomperts, R.L. Martin, D.J. Fox,
T.A. Keith, M.A. Al-Laham, C.Y. Peng, A. Nanayakkara, M. Challacombe, P.M.W.
Gill, B. Johnson, W. Chen, M.W. Wong, J.L. Andres, C. Gonzalez, M. Head-
Gordon, E.S. Replogle, J.A. Pople, Gaussian 98, Revision A.9, Gaussian Inc.,
Pittsburgh, PA, 1998.
[10] H.U. Daeniker, J. Druey, Helv. Chim. Acta 95 (1962) 2441.
[11] V.G. Yashunskii, L.E. Holodov, S.A. Zotova, Zur. Vseros. Him. Obsh. Im. D.I.
Mendeleeva (1964) 105.
[12] Z.A. Oloviannikova, B.I. Briantsev, I.S. Slusarenko, V.G. Yashunskii, Him. Het.
Soed. (1975) 1198.
[9] R.F.W. Bader , Atoms in Molecules. A Quantum Theory, Clarendron Press,
Oxford, 1990.
[13] M. Gotz, K. Grozinger, J. Het. Chem. 7 (1970) 123.
[14] G.M. Sheldrick, SHELXTL-97, Version 5.10, Bruker AXS Inc., Madison, WI, USA.