Nickel(II) bis(diphenylphosphino)amide: Redox-coupling of dppa ligands in coordination sphere of Ni2+ and some other properties

Article abstract of DOI:10.1016/j.jorganchem.2005.02.007

The reactions of Ni^II[(PPh₂)₂N] ₂ (2) with various reagents are described. Addition of two moles of carbon monoxide to 2, at 20°C and atmospheric pressure leads to the redox coupling of dppa ligands and formation of zero-valent nickel complex (CO) ₂Ni(Ph₂P-N=PPh₂PPh₂=NPPh ₂) (4). The nickel atom in 4 has a tetrahedral coordination and is incorporated into the NiP₄N₂ ring adopting a distorted chair conformation with phosphorus-phosphorus bond length 2.2777(5) A?. Contrary to CO, sulphur dioxide reacts with 2 to form simple adduct (SO ₂)Ni^II[(PPh₂)₂N]₂. The reaction of 2 with allyl bromide runs as alkylation of dppa ligand to form All-N(PPh₂)₂NiBr₂. The reduction of 2 with metallic sodium in THF gives Ni(0) complex, HN(PPh₂) ₂Ni(Ph₃P)₂ (7). The electrochemical reduction of 2 in CH₂Cl₂ takes place in two steps: reversible one-electron and quasi-reversible three-electron step.

Full text of DOI:10.1016/j.jorganchem.2005.02.007

Journal of Organometallic Chemistry 690 (2005) 1814–1821
www.elsevier.com/locate/jorganchem
Nickel(II) bis(diphenylphosphino)amide: Redox-coupling
of dppa ligands in coordination sphere of Ni2+
and some other properties
a
a,
a
Vyacheslav V. Sushev , Alexander N. Kornev *, Yurii A. Kurskii ,
a
a
b
Olga V. Kuznetsova , Georgy K. Fukin , Yulia H. Budnikova , Gleb A. Abakumov
a
a
G.A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences, 49 Tropinin Street, 603950 Nizhny Novgorod, Russia
b
A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Centre of the Russian Academy of Sciences, 8 Arbuzov Street,
420088 Kazan, Russian Federation
Received 11 January 2005; accepted 7 February 2005
Available online 17 March 2005
Abstract
The reactions of NiII[(PPh2)2N]2 (2) with various reagents are described. Addition of two moles of carbon monoxide to 2,
at 20 ꢀC and atmospheric pressure leads to the redox coupling of dppa ligands and formation of zero-valent nickel complex
(CO)2Ni(Ph2PAN@PPh2APPh2@NPPh2) (4). The nickel atom in 4 has a tetrahedral coordination and is incorporated into the
˚
NiP4N2 ring adopting a distorted chair conformation with phosphorus–phosphorus bond length 2.2777(5) A. Contrary to CO, sul-
phur dioxide reacts with 2 to form simple adduct (SO2)NiII[(PPh2)2N]2. The reaction of 2 with allyl bromide runs as alkylation of
dppa ligand to form All-N(PPh2)2NiBr2. The reduction of 2 with metallic sodium in THF gives Ni(0) complex, HN(PPh2)2Ni(Ph3P)2
(7). The electrochemical reduction of 2 in CH2Cl2 takes place in two steps: reversible one-electron and quasi-reversible three-electron
step.
ꢁ 2005 Elsevier B.V. All rights reserved.
Keywords: Transition metal complexes; Phosphazanes; Phosphinoamides; Amidoimidophosphoranes; X-ray diffraction
1. Introduction
P–P coupled product, Ph2PAN@PPh2APPh2@NAPPh2
[3]. On the other hand, 1 reacts with a number of inor-
ganic halides to form unexpected products of cyclophos-
phazene type [Ph2P(NPPh2)]2M (M = Co [4], Ni, Pd [5]),
[Ph2P(NPPh2)]M[(Ph2P)2N] (M = FeII, PtII) [6].
Bis(diphenylphosphino)amine, HN(PPh2)2, is one of
the much used and intriguing phosphorus–nitrogen li-
gands in transition-metal chemistry [1]. It demonstrates
coordinative versatility both in its neutral form and as
an anion [Ph2PNPPh2]ꢀ (dppa) [2]. Moreover, the last
one is implicated easily into redox processes (oxidative
splitting and scrambling of the ligand), which usually
are accompanied with PIII ! PV transitions. So, the
oxidation of lithium bis(diphenylphosphino)amide,
LiN(PPh2)2, (1) with molecular iodine affords single,
3MCl2 þ 6LiNðPPh2Þ
! ½ðPh2PNÞ PPh2ꢁ2 M þ 2ðPh2PÞ N þ 2M þ 6LiCl
2
2
3
M ¼ Co; Ni
Tris(diphenylphosphino)amine, (Ph2P)3N, was the main
product (55%) in the reaction of germanium dichloride
dioxanate with 1 [7,8]. The reaction of LiN(PPh2)2 with
PCl3, lead to the mixture of cyclic {N(Ph2P@
PAPPh2)2N}, and linear {(Ph2PAN@PPh2ꢀ)2} phos-
phazenes [3].
*
Corresponding author. Tel.: +78312 12 66 52; fax: +78312 12 74 97.
E-mail address: akornev@imoc.sinn.ru (A.N. Kornev).
0022-328X/$ - see front matter ꢁ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.02.007

V.V. Sushev et al. / Journal of Organometallic Chemistry 690 (2005) 1814–1821
1815
Recently, we have synthesised nickel(II) bis(diph-
enylphosphino)amide (2) in disproportionation reaction
of nickel(I) bis(triphenylphosphino)bis(trimethylsilyl)-
amide with (Ph2P)2NH:
strong absorption at 403 nm (e = 1350) arose. Solvent
removal led to a brown polycrystalline solid 3, whose
IR spectrum shows two carbonyl bands 1980 and
1920 cmꢀ1, indicating the presence of two CO mole-
cules, coordinated to the nickel atom.
Ph3P
PhMe
Ni N(SiMe3)2
+ 3 (Ph2P)2NH
2
O
-2(Me3Si)2NH
-2Ph3P
Ph
Ph3P
Ph Ph
Ph
Ph
P
Ph
P
Ph
N
C
Ph
N
P
P
P
II
CO
II
Ni
C
Ni
N
N
Ph
Ph Ph
NiII
Ph
P
P
Ph
Ph
P
P
P
P
P
Ph
Ph
P
P
Ph
Ph
Ph3P
O
Ph
Ph
Ph
Ph
Ni0
Ph
N-H
Ph
N
+
N
3
2
Ph3P
Ph
N
2P
PPh2
Ph
Ph
Ph
Ph
N
P
2
P
Ph2
Ph2
0
Ni
C
C
The reaction affords good yield of 2 according stoi-
O
O
chiometry of the equation. In this paper we report un-
usual properties of 2 including oxidative coupling of
dppa ligands, the electrochemical and chemical reduc-
tion, interaction with SO2 and allyl bromide, as well as
a novel structural investigation of 2.
4
Our attempts to detect the coordination of only one
CO-ligand to nickel atom were unsuccessful. The pro-
posed intermediate complex 3 in THF (or CH2Cl2) solu-
tion undergoes slow (during ꢂ10 h) transformation to
the compound 4 (as judged by 31P NMR monitoring).
The rearrangement proceeds quite fast (ꢂ15 min) when
irradiated by soft UV (ꢂ330 nm, Pyrex). The absorption
band is shifted to 400 nm, and its intensity sharply de-
creases (e = 330). The 31P NMR spectrum of 4 corre-
sponds to the AA0XX0 spin system containing two
multiplets at 68.0 ppm (PIII) and 5.1 ppm (PV). IR spec-
trum of 4 shows new strong absorptions at 1210 and
1160 cmꢀ1, assigned to the stretching vibrations of the
NAPV@N moiety.
Yellow crystals of 4 suitable for X-ray analysis were
prepared from a THF/toluene (1:1) mixture. The X-ray
diffraction study of the complex (Fig. 1) showed that the
nickel atom has a tetrahedral coordination and is incor-
porated into the NiP4N2 ring adopting a distorted chair
conformation. Note that in the similar previously stud-
ied platinum complex, Me2Pt(PPh2NPPh2PPh2NPPh2)
[10], the metal atom has a square-planar environment
while the PtP4N2 ring adopts a boat conformation.
The different conformations of nickel and platinum
complexes seem to result from significantly different
P(1)–P(4) interatomic distances which are primarily
determined by P–M–P bond angles {107.65(2)ꢀ for 4
and 94.0(1)ꢀ for the platinum complex}.
2. Results and discussion
Previously, we have shown [9] that central core of
nickel(II) bis(diphenylphosphino)amide (2) is flat at
150 K. It was revealed further that crystals of 2 being
red at room temperature turned yellow at 150 K. The
compound has no 31P NMR spectrum at 20 ꢀC. It was
reasonable to study the structure of the molecule at
room temperature. The X-ray investigation at 293 K
has shown however that the structure of the molecule
changes marginally. The central core of 2 retains flat
geometry. Apparently, the temperature dependent color
transition has an electronic nature. It may be the case
when small deviation out of plain conformation under
change of temperature causes considerable changes in
electron levels.
2.1. Reactivity
2.1.1. Interaction with carbon monoxide
A solution of 2 in THF absorbs carbon monoxide
(two moles per one mole of 2) at atmospheric pressure
and ambient temperature with the rate of gas diffusion
into a solution. The red colour of the solution becomes
markedly deeper. The electronic spectrum showed a fast
disappearance of absorption bands of the initial com-
plex at 414 nm (e = 80), 431 nm (e = 660) while new
The Ni(1)–P(1) and Ni(1)–P(4) bond distances are
˚
2.2073(4) and 2.2129(4) A, respectively; they are shorter
˚
than the Pt–P distances (2.283(3), 2.285(3) A) in the
platinum complex Me2Pt(PPh2NPPh2PPh2NPPh2) [10]

1816
V.V. Sushev et al. / Journal of Organometallic Chemistry 690 (2005) 1814–1821
is observed in the Pt complexes [10]. The Ni(1)–C(1, 2)
˚
and C(1, 2)–O(1, 2) distances are 1.776(2), 1.763(2) A
˚
and 1.145(2), 1.147(2) A, which is close to the corre-
˚
˚
sponding Ni–C (1.763(2) A) and C–O (1.142(3) A) dis-
tances in (OC)2Ni0(PPh3)2 [13].
Discussing the rearrangement it is necessary to
recollect another interesting example of related
Ni(II) ! Ni(0) conversion. So chelating nickel(II) phos-
phineamide complex reacts with carbon monoxide to
generate new product in which C–N reductive coupling
has taken place [14]:
3
CH2
CH2
Me2Si
Me2Si
PPh2
Me2Si
PPh2
CO
N
Ph(O)C-
Ni C(O)Ph
N
(CO)
Ni
2
Me2Si
PPh2
PPh2
CH2
CH2
Fig. 1. Molecular structure of 4. Phenyl rings are omitted for clarity.
˚
and are comparable with similar distances (2.221(1) A)
in (OC)2Ni0(PPh3)2 [11]. Nonetheless, the P(1)–P(4) dis-
tance between the phosphorus atoms bound to nickel in
˚
compound 4 is 3.568(1) A, which is substantially longer
2.1.1.1. Solubility of 2 and crystal growth. Nickel(II)
bis(diphenylphosphino)amide (2) shows unusual solubil-
ity in different solvents. It is easily soluble in CH2Cl2
(UV/vis spectroscopy shows single transition at
450 nm), but reacts with CHCl3 for 1 h to form insoluble
red product. THF can dissolve 2, however the formation
of red solution takes heating for a long time (ꢂ4 h).
Recovering of 2 from THF or CH2Cl2 solution gave
unchangeable product as judged by IR spectroscopy.
Initial addition of MeCN to crystals of 2 causes its
immediate dissolution, however a brown-yellow precip-
itate is formed soon. Subsequent addition of acetonitrile
results in complete dissolution of last one. Interestingly,
this solution does not absorb CO at ambient conditions.
The observed behavior of 2 may be the result of double-
sided basket-like structure, which may delay equilibrium
coordination of the solvent molecules. Note that
crystallization of known Ni(II) complex, containing
neutral bis(diphenylphosphino)metane ligand (dppm)-
[Ni(dppm)2](BF4)2, from acetonitrile, gave five-coordi-
nate compound [Ni(dppm)2(MeCN)](BF4)2 [15].
˚
than the same distance in the Pt complex (3.338(1) A
[10]). Such a difference in P–P distances points to the
flexibility of the ligand and its capability to form com-
plexes with metals of different radii.
˚
The P(2)–P(3) distance (2.2777(5) A) in 4 is markedly
˚
longer than that in the free ligand (2.232(2) A) [3], which
adopts a zigzag configuration. In the platinum complexes
Me2Pt(PPh2NPPh2PPh2NPPh2) and IMePt(PPh2NPPh2-
PPh2NPPh2) similar P(2)–P(3) distances are 2.290(4) and
˚
2.242(5) A, respectively [10]. The P(2)–P(3) bond length is
obviously to be determined mainly by the electronic state
of a metal and the strength of its bond to phosphorus
atom rather than by the ring size. It should be noted that
this bond can be readily broken when the free ligand
reacts with zerovalent palladium or platinum complexes
[10].
ðPh3PÞ M0 þ PPh2NPPh2PPh2NPPh2
4
! ½NðPPh2Þ ꢁ MII þ 4Ph3P
2 2
Note that there are shortened intramolecular Cꢃ ꢃ ꢃC
distances between the phenyl rings in the –Ph2P(2)–
2.1.2. Interaction of 2 with sulfur dioxide
˚
P(3)Ph2– moieties (3.281(3) A) in compound 4, as well
as between the carbonyl group and phenyl ring
˚
(3.302(3) A) as compared with normal van der Waals
It was found that solution of nickel(II) bis(di-
phenylphosphino)amide in THF easily absorbs one
equivalent of sulfur dioxide to form insoluble yellow
fine-crystalline powder of 5. The efficient magnetic
moment observed for 5 (2.3 lB) revealed Ni2+ oxidation
state. So, there are no coupling of dppa ligands took
place in this case. The infrared spectrum of 5 showed
m(SO2) peaks at: 1200 (m), 1130 (vs), 1100 (m), 1030
(m) cmꢀ1. The vibrational frequencies of the SO2 ligand
˚
contacts C–C, 3.42 A [12].
The P–N distances in complex 4 may be divided into
two groups: formally ordinary bonds, P(1)–N(1)
˚
(1.672(1) A) and P(4)–N(2) (1.657(1) A), and double
˚
˚
bonds, P(2)–N(1) (1.575(1) A) and P(3)–N(2)
˚
˚
(1.570(1) A), which differ by ꢂ0.1 A. A similar situation

V.V. Sushev et al. / Journal of Organometallic Chemistry 690 (2005) 1814–1821
1817
in 5 are in the range established for those nickel com-
plexes, which contain the pyramidal NiSO2 geometry
[16].
The 31P NMR spectrum of 6 contains single reso-
nance at 51.7 ppm. X-ray analysis has shown that the
Ni(II) atom has a distorted square-planar coordination
(Fig. 2). The Ni(1)–P(1)N(1)–P(2) metallocycle is also
planar. The bromine atoms occupy a trans-positions rel-
atively of the Ni(1)–P(1)N(1)–P(2) metallocycle. The
deviations of Br(1) and Br(2) atoms from the Ni(1)–
O
O
Ph
N
Ph Ph
Ph
Ph
S
Ph
P
P
P
Ph
˚
˚
Ph
P(1) P(2) plain are +0.341 A and ꢀ0.186 A, respectively.
P
-
II
P
Ni
N
NiII
The Ni (1)–P(1,2); Ni(1)–Br(1,2) and N(1)–P(1,2) dis-
SO2
-
N
N
Ph
˚
˚
tances are 2.112(1), 2.122(2) A; 2.321(1), 2.319(1) A
P
P
P
Ph
˚
and 1.692(4), 1.709(4) A, respectively. In the similar
Ph
Ph
Ph Ph
known complex, MeN[(o-PriC6H4)2P]2NiBr2 [18], only
Ph
Ph
5
2
˚
the Ni–P (2.161 A) distances are elongated due to steric
hindrances as compared to the Ni–P distances in 6 while
It is known that sulfur dioxide forms charge-transfer
complexes with tetrtiary amines [17]. So, the formation
of –O–S(O)–N(PPh2)2Ni+2 moiety is also possible. Note,
however, that such a charge division will be energetically
unfavourable; furthermore, an excess of SO2 gave the
same product, containing one SO2 molecule per nickel
atom according element analysis. Therefore, the coordi-
nation of SO2 to the nickel atom is more probable.
˚
˚
the Ni–Br (2.328 A) and N–P (1.688 A) distances are
close to the analogous bond lengths in 6. The allyl frag-
ment C(25)–C(26)–C(27) is planar. The C(25)–C(26) and
˚
C(26)–C(27) distances are 1.484(8) and 1.310(7) A.
These distances are close to a typical C(sp3)–C(sp2)
2
(1.503 A) and C(sp )–C(sp ) (1.299 A) bond lengths in
2
˚
˚
the CACH@CH2 fragments [19]. The distance N(1)–
˚
C(25) 1.477(6) A is close to the analogous bond length
i
in MeN[(o-Pr C6H4)2P]2NiBr2 (1.474 A [18]). The devia-
˚
2.1.3. Reaction of 2 with allyl bromide
tion of C(25) atom from the plane of the cycle Ni(1)–
˚
P(1)–N(1)–P(2) is (0.298 A). The dihedral angle between
C(25)–C(26)–C(27) and Ni(1)–P(1)–N(1)–P(2) planes is
84.0ꢀ (see Fig. 2).
The reaction of 2 with excess of allyl bromide proceed
smoothly to form deep red solution. Keeping this solu-
tion at room temperature gives wine-red crystals of
new complex 6.
High reactivity of 2 toward allyl bromide may be re-
sult of essential negative charge of nitrogen atoms. The
mother liquor, remaining after crystallization of 6, was
monitored by 31P NMR spectroscopy. The observed sin-
gle resonance at d 24.0 ppm is not in contradiction with
the presence of allylbis(diphenylphosphino)amine
CH2@CHACH2AN(PPh2)2 (the second product of the
reaction). Maintaining of this solution for a long time
gave more complicated mixture of phosphorus-contain-
ing products, according to the 31P NMR spectroscopy.
[N(PPh2)2]2Ni + 2 AllBr
Br
Br
Ph
2P
+ All-N(PPh2)2
other products
All-N
Ni
Ph2
6
All-N(PPh2)2 + AllBr (exc)
All: CH2=CH-CH2-
Fig. 2. Molecular structure of All-N(PPh2)2NiBr2 (6).

1818
V.V. Sushev et al. / Journal of Organometallic Chemistry 690 (2005) 1814–1821
It worth note that methylation of dppa derivatives of
platinum and palladium with methyl ether of fluorosul-
phonic acid proceed in analogous way [20]:
It worth noting, bis(cyclopentadienyl)cobalt being
strong reducing agent, does not react with 2 in THF
solution, perhaps due to steric hindrances.
MðdppaÞ þ CH3OSO2F
2
2þ
3. Experimental
! f½CH3NðPPh2Þ ꢁ Mg ðꢀOSO2FÞ M ¼ Pt; Pd
2 2
2
3.1. General considerations
2.1.4. Reduction of 2
Solvents were purified following standard methods
[21]. Toluene and methylene chloride were thoroughly
dried and distilled over P2O5 prior to use. Ether and
THF were dried and distilled over Na/benzophenone.
Bis(diphenylphosphino)amine, (Ph2P)2NH, was pre-
pared according to [22]. All manipulations were per-
formed with rigorous exclusion of oxygen and
moisture, in vacuum or under an argon atmosphere
using standard Schlenk techniques. An CO and SO2-
gas was dried over phosphorus(V) oxide.
Spectrophotometric determination of nickel with
dimethylglioxime was provided by the method [23];
Infrared spectra were recorded on a Perkin–Elmer
577 spectrometer from 4000 to 400 cmꢀ1 in Nujol.
NMR spectra were recorded in CDCl3 or C6D6 solu-
tions using ‘‘Bruker DPX-200’’ device, with Me4Si as
internal standard.
Cyclic voltammograms were recorded at glassy car-
bon electrode with a 1.5 mm diameter in a thermostati-
cally controlled cell in argon atmosphere. Silver
electrode Ag/AgNO3 (0.01 mol lꢀ1 solution in MeCN)
served as a reference electrode and platinum wire served
as an auxiliary electrode. Curve registration was per-
formed with potentiostat PI-50-1 (USSR). Scan rate
was 50 mV sꢀ1 (Fig. 3).
Since compound 2 contains divalent nickel, it may be
reduced to Ni+1 or Ni0 state. The electrochemical reduc-
tion of 2 occurs by two steps. The primary electron-
transfer step is reversible one-electron process (Fig. 4).
The second step is quasi-reversible three-electron reduc-
tion. Obviously, the second step touches dppa-ligand it-
self along with metallocentre. Eventually, it results in
destruction of the complex.
The interaction of 2 with metallic sodium in THF at
20 ꢀC proceeds slowly to form dark-brown solution and
no tractable products. Meanwhile, addition of equiva-
lent amounts of Ph3P to this solution and subsequent
crystallization from ether affords large dark-brown
crystals of Ni(0) mixed-ligand complex HN(PPh2)2-
Ni(Ph3P)2 (7). The 31P NMR spectrum of 7 corresponds
to the AA0XX0 spin system containing two triplets at d
61.9 and 33.5 ppm with splitting constant JPP 20.3 Hz.
The X-ray diffraction data has shown that the Ni(1)
atom has a distorted tetrahedral coordination (4). The
˚
Ni(1)–P(1,2) distances 2.1983(5), 2.2006(5) A are slightly
˚
longer than the Ni(1)–P(3,4) (2.1842(5), 2.1875(5) A)
distances. This is indicative of weaker dppa coordina-
tion to nickel atom by comparison with Ph3P ligand.
At the same time the distances Ni(1)–P(1,2) are much
elongated as compared to Ni2+–P distances in 6
{2.112(1), 2.122(2) A} and the Ni2+–P distances in
˚
MeN[(o-PriC6H4)2P]2NiBr2 (2.161 A [18]). The nitro-
2
˚
gen–phosphorus bond lengths in
˚
7
1.698(1) A} are very close to similar N–P distances in
{1.705(1),
i
6 (1.692(4), 1.709(4) A) and in MeN[(o-Pr C6H4)2P]2-
˚
˚
NiBr2 (1.688 A [18]). The Ni–P co-ordination bond
strength is revealed also in the observed PNP bond
angles which are increased on going from Ni2+ to Ni0
complexes: 94.3(2)ꢀ in 6 (Ni2+), 100.98ꢀ in MeN[(o-
PriC6H4)2P]2NiBr2 (Ni2+) and 102.21(8)ꢀ in 7 (Ni0).
The dihedral angle between the planes of Ni(1)–P(1)–
N(1)–P(2) and Ni(1)–P(3)–P(4) fragments in 7 are
81.5ꢀ, that apparently minimizes steric repulsion of Ph
groups of Ph3P and dppa ligands.
Obviously, the formation of 7 is not possible without
hydrogen abstraction from the solvent.
PPh3
PPh3
PPh2
PPh2
Na/THF
Ph3P
[N(PPh2)2]2Ni
H-N
Ni
Fig. 3. Cyclic voltammograms for NiII[(PPh2)2N]2 (2) (5 · 10ꢀ3 M) in
2
CH2Cl2 + Et4NBF4 (10ꢀ1 M).
7

V.V. Sushev et al. / Journal of Organometallic Chemistry 690 (2005) 1814–1821
1819
Fig. 4. Molecular structure of HN(PPh2)2Ni(Ph3P)2 (7). Phenyl rings are omitted for clarity.
Table 1
The details of crystallographic, collection and refinement data for 4, 6 and 7
4
6
7
Empirical formula
Formula weight
Temperature (K)
Crystal system
C
883.43
50H40N2NiO2P4
C27H25Br2NNiP2
643.95
100(2)
C62H56NNiO0.5P4
1005.67
100(2)
100(2)
Monoclinic
P21/n
Monoclinic
P21/n
Monoclinic
P21/n
Space group
Unit cell dimensions
˚
a (A)
13.7895(9)
22.7483(15)
13.9372(9)
98.4310(10)
4324.7(5)
10.4261(12)
19.107(2)
13.1969(15)
99.234(2)
2594.9(5)
4
11.6497(11)
36.480(3)
12.2311(11)
92.563(2)
5192.8(8)
4
˚
b (A)
˚
c (A)
b (ꢀ)
V (A)
3
˚
Z
4
1.357
Dcalc (g/cm3)
1.648
3.967
1288
1.286
0.539
2108
Absorption coefficient (mmꢀ1
F(000)
)
0.640
1832
Crystal size (mm3)
0.30 · 0.20 · 0.20
1.74–29.02
ꢀ18 6 h 6 18
ꢀ18 6 k 6 30
ꢀ18 6 l 6 18
31151
0.40 · 0.30 · 0.20
1.89–29.05
ꢀ11 6 h 6 14
ꢀ26 6 k 6 20
ꢀ17 6 l 6 18
18702
0.40 · 0.40 · 0.40
1.76–25.00
ꢀ13 6 h 6 13
ꢀ43 6 k 6 43
ꢀ14 6 l 6 14
36415
h Range for data collection (ꢀ)
Index ranges
Reflections collected
Independent reflections [Rint
]
11425 [0.0240]
SADABS
6880 [0.0912]
9146 [0.0321]
Absorption correction
Maximum/minimum transmission
Refinement method
0.8828/0.8313
Full-matrix least-squares on F2
11425/0/692
1.042
0.5042/0.2998
0.8134/0.8134
Data/restraints/parameters
Goodness-of-fit on F2
6880/0/298
0.923
9146/10/644
1.069
Final R indices [I > 2r (I)]
R = 0.0344,
Rw = 0.0861
R = 0.0452,
Rw = 0.0920
0.605/ꢀ0.306
R = 0.0520
Rw = 0.0876
R = 0.1204
Rw = 0.1061
0.916/ꢀ1.143
R = 0.0332
Rw = 0.0827
R = 0.0377
Rw = 0.0846
0.533/ꢀ0.227
R indices (all data)
3
Largest difference in peak and hole (e A )
˚

1820
V.V. Sushev et al. / Journal of Organometallic Chemistry 690 (2005) 1814–1821
Table 2
˚
The selected distances (A) and angles (ꢀ) for 4, 6 and 7
4
6
7
˚
Bond distance (A)
Ni(1)–P(1)
Ni(1)–P(4)
Ni(1)–C(1)
Ni(1)–C(2)
P(1)–N(1)
2.2073(4)
2.2129(4)
1.776(2)
1.763(2)
1.672(1)
1.575(1)
1.657(1)
1.570(1)
1.145(2)
1.147(2)
Ni(1)–Br(1)
Ni(1)–Br(2)
Ni(1)–P(1)
Ni(1)–P(2)
P(1)–N(1)
2.3212(7)
2.319(1)
2.112(1)
2.122(2)
1.692(4)
1.709(4)
1.477(6)
1.484(8)
1.310(7)
Ni(1)–P(1)
Ni(1)–P(2)
Ni(1)–P(3)
Ni(1)–P(4)
N(1)–P(1)
N(1)–P(2)
2.1983(5)
2.2006(5)
2.1842(5)
2.1875(5)
1.705(1)
1.698(1)
P(2)–N(1)
P(4)–N(2)
P(2)–N(1)
N(1)–C(25)
C(25)–C(26)
C(26)–C(27)
P(3)–N(2)
O(1)–C(1)
O(2)–C(2)
Bond angles (ꢀ)
C(2)–Ni(1)–C(1)
C(2)–Ni(1)–P(1)
C(1)–Ni(1)–P(1)
C(2)–Ni(1)–P(4)
C(1)–Ni(1)–P(4)
P(1)–Ni(1)–P(4)
N(1)–P(1)–Ni(1)
P(2)–N(1)–P(1)
N(2)–P(3)–P(2)
P(3)–N(2)–P(4)
N(2)–P(4)–Ni(1)
O(1)–C(1)–Ni(1)
O(2)–C(2)–Ni(1)
108.38(7)
103.60(5)
105.38(5)
116.55(5)
114.16(5)
107.65(2)
121.14(5)
127.63(8)
114.21(5)
130.88(9)
119.54(5)
172.8(2)
P(1)–Ni(1)–P(2)
P(1)–Ni(1)–Br(2)
P(2)–Ni(1)–Br(2)
P(1)–Ni(1)–Br(1)
P(2)–Ni(1)–Br(1)
Br(2)–Ni(1)–Br(1)
N(1)–P(1)–Ni(1)
N(1)–P(2)–Ni(1)
P(1)N(1)–P(2)
73.77(5)
93.09(5)
166.20(4)
164.61(5)
93.49(4)
100.12(3)
95.2(1)
P(3)–Ni(1)–P(4)
P(3)–Ni(1)–P(1)
P(4)–Ni(1)–P(1)
P(3)–Ni(1)–P(2)
P(4)–Ni(1)–P(2)
P(1)–Ni(1)–P(2)
P(2)–N(1)–P(1)
108.18(2)
124.00(2)
115.40(2)
111.05(2)
121.37(2)
74.02(2)
102.21(8)
94.3(2)
96.7(2)
N(1)–C(25)–C(26)
C(27)–C(26)–C(25)
112.7(4)
123.3(5)
173.3(2)
3.2. X-ray structure determinations
carbon monoxide. Absorption of 22.4 mL (1.0 mmol) of
CO was occurred for about 30 s. Red solution immedi-
ately turned dark violet-brown. The electronic spectrum
shows band at 403 nm (e = 1350). An aliquot part was
separated; the solvent was removed in vacuum; remain-
ing brown powder (2), was analyzed by IR spectroscopy:
1980 (s), 1920 (s), 1430 (m), 1100 (s), 910 (s), 870 (m),
740 (m), 700 (s), 550 (w), 520 (w), 500 (w).
The X-ray diffraction data were collected on a
SMART APEX diffractometer (graphite-monochro-
mated, Mo Ka-radiation, u–x-scan technique, k =
˚
0.71073 A). The intensity data were integrated by SAINT
program [24]. SADABS [25] was used to perform area-
detector scaling and absorption corrections. The struc-
tures were solved by direct methods and were refined
on F2 using all reflections with SHELXTL package [26].
All non-hydrogen atoms were refined anisotropically.
All H atoms in 4 were found from Fourier synthesis
and refined isotropically. The H atoms in 6 and 7 were
placed in calculated positions and refined in the ‘‘rid-
ing-model’’ except the H(1) atom in 7 which was found
from Fourier synthesis and refined isotropically. The
complex 7 contains a disordered solvate molecule of
Et2O. The details of crystallographic, collection and
refinement data for 4, 6 and 7 are shown in the Table
1. The selected distances and bond angles for 4, 6 and
7 are shown in the Table 2.
The ampoule was irradiated with UV lamp of low
pressure for 20 min. The yellow solution was concen-
trated. Crystals of 4 were obtained from THF/toluene
(1:1) mixture. Yield 0.37g (85%). Anal. Calc. for
C50H40N2NiO2P4: C, 67.98; H, 4.56; Ni, 6.64. Found:
C, 68.32; H, 4.48; Ni, 6.60%. IR (Nujol) m(cmꢀ1): 3060
(w), 1980 (vs), 1920 (vs), 1590 (w), 1430 (s), 1300
(ww), 1210 (vs), 1160 (sh), 1100 d (m), 1030 (w), 1000
(w), 750 (s), 700 (s), 530 (sh), 520 (s), 490 (m), 440
(m). 31P{1H} NMR (CDCl3), d 68.0 (PIII, m, AA0); 5.1
V
2
3
(P , m, XX0); JAX þ JAX ¼ 39:7 Hz; 1JX;X ¼ ꢄ85:0,
0
0
2JAX
=
53.5, JAX þ JA X ¼ ꢄ13:5; 2JA;A ¼ ꢄ11:0}.
3
4
0
0
0
0
3.3.2. Interaction of 2 with SO2
3.3. Synthesis
An excess of SO2 (33.6 mL, 1.5 mmol) was added to a
solution of 2 (0.41 g, 0.5 mmol) in THF at ambient con-
ditions. A yellow fine-crystalline precipitate of 5 was
formed immediately. The precipitate was filtered,
washed with THF and dried in vacuum. Yield 0.39 g
(88%). Anal. Calc. for C48H40P4N2NiSO2: C, 64.67; H,
3.3.1. Interaction of 2 with CO, synthesis of
(CO)2Ni(Ph2PAN@PPh2APPh2@NAPPh2) (4)
A Pyrex ampoule containing 0.41 g (0.5 mmol) of 2 in
15 mL of toluene was attached to a mercury burette with

V.V. Sushev et al. / Journal of Organometallic Chemistry 690 (2005) 1814–1821
1821
4.52; Ni, 6.58; S, 3.60. Found: C, 64.61; H, 4.48; Ni,
6.63; S, 3.54%. IR (Nujol) m (cmꢀ1): 1200 (m), 1180
(w), 1130 (vs), 1100 (m), 1070 (w), 1030 (m), 1000 (m),
920 (m), 820 (m), 750 (s), 720 (s), 700 (vs), 560 (s), 510
(s). leff = 2.3 lB.
schools 1649.2003.3, 1652.2003.3) for financial support
of this work.
References
3.3.3. All-N(PPh2)2NiBr2 (6)
[1] P. Bhattacharyya, J.D. Woollins, Polyhedron 14 (1995) 3367.
[2] M. Witt, H.W. Roesky, Chem. Rev. 94 (1994) 1163.
[3] P. Braunstein, R. Hasselbring, A. Tiripicchio, F. Ugozzoli, J.
Chem. Soc. Chem. Comm. (1995) 37.
An excess of allyl bromide (2 mL) was added to 0.3 g
of 2. Red-cerise solution was kept at 20 ꢀC for 3 h. Dur-
ing this time dark red-cerise crystals of 5 were formed.
Crystals were separated by filtration, washed with tolu-
ene and dried in vacuum. Yield 0.20 g (85%). 31P {1H}
NMR (CDCl3): d 51.6 ppm; 1H NMR d 8.3–7.4 (m,
20H, Ph); 5.25 (m, 1H, ACH@); 4.83 (m, 1H, CH2@);
4.76 m, 1H (CH2@); 3.38 (m, 2H, –CH2–). Anal. Calc.
for C27H25Br2NNiP2: C, 50.36; H, 3.91; Ni, 9.12; Br,
24.82. Found: C, 50.45; H, 4.05; Ni, 9.04; Br, 24.13%.
IR (Nujol) m (cmꢀ1): 1430 (w), 1170 (w), 1110 (s), 1010
(m), 940 (w), 830 (m), 760 (m), 730 (w), 700 (s), 600
(w), 570 (m), 520 (s). NMR-monitoring of mother liquor
showed signal 31P d 24.0 ppm, which may be tentatively
refer to allyldiphenylphosphine.
[4] J. Ellerman, J. Sutter, F.A. Knoch, M. Moll, Angew. Chem., Int.
Ed. Engl. 32 (1993) 700.
[5] J. Ellerman, J. Sutter, C. Schelle, F.A. Knoch, M. Moll, Z.
Anorg. Allg. Chem. 619 (1993) 2006.
[6] J. Ellerman, P. Gabold, C. Schelle, F.A. Knoch, M. Moll, W.
Bauer, Z. Anorg. Allg. Chem. 621 (1995) 1832.
[7] Ya.V. Fedotova, A.N. Kornev, V.V. Sushchev, Yu.A. Kurskii,
G.K. Fukin, G.A. Abakumov, Doklady Chem. 396 (1) (2004)
92.
[8] A.N. Kornev, Ya.V. Fedotova, V.V. Sushev, G.K. Fukin, G.A.
Abakumov, Amidophosphine derivatives of germanium (II), in:
VII International Conference on the Chemistry of Carbenes and
Related Intermediates, Book of Abstracts, Kazan, Russia, 23–26
June, 2003, p. 93 {here (P41) means poster 41}.
[9] V.V. Sushev, A.N. Kornev, Y.V. Fedotova, Y.A. Kursky, T.G.
Mushtina, G.A. Abakumov, L.N. Zakharov, A.L. Rheingold, J.
Organometal. Chem. 676 (2003) 89.
3.3.4. Interaction of 2 with metallic sodium
The reaction of 2 (0.27 g, 0.33 mmol) with an excess
of sodium metal in THF (10 mL) at 20 ꢀC proceeds
slowly (24 h) to form bright-orange then dark-brown
solution. The solution was decanted, THF was changed
for diethyl ether and 0.2 g of Ph3P (0.76 mmol) was
added. Keeping the mixture overnight at 10 ꢀC affords
large dark-brown crystals of Ni(0) mixed-ligand com-
plex HN(PPh2)2Ni(Ph3P)2(Et2O)0.5 (7). Yield 0.14 g
(41%). IR (nujol) (cmꢀ1): 3050 w, 1580 w, 1430 m,
1300 m, 1200 m, 1180 m, 1120 m, 1090 s, 1070 w,
1020 m, 790 m, 730 s, 700 vs, 550 m, 510 vs. 31P
[10] A.M.Z. Slawin, M.B. Smith, J.D. Woollins, J. Chem. Soc.,
Dalton Trans. (1997) 3397.
[11] C. Kruger, Y.-H. Tsay, Cryst. Struct. Commun. 3 (1974) 455.
[12] Yu.V. Zefirov, P.M. Zorky, Rus. Chem. Rev. l64 (1995) 415.
[13] C. Kruger, Y.-H. Tsay, Cryst. Struct. Commun. 3 (1974) 455.
[14] M.D. Fryzuk, P.A. MacNeil, S.J. Rettig, J. Organometal. Chem.
332 (1987) 345.
[15] A. Miedaner, R.C. Haltiwanger, D.L. DuBois, Inorg. Chem. 30
(1991) 417.
[16] D.C. Moody, R.R. Ryan, Inorg. Chem. 18 (1979) 223.
[17] J.J. Oh, M.S. LaBarge, J. Matos, J.W. Kampf, K.W. Hillig II,
R.L. Kuczkowski, J. Am. Chem. Soc. 113 (1991) 4732.
[18] N.A. Cooley, S.M. Green, D.F. Wass, K. Heslop, A.G. Orpen,
P.G. Pringle, Organometallics 20 (2001) 4769.
2
NMR (C6D6), d ppm: 61.9 (t, JPP 20.3, Ph2P), 33.5 (t,
1
2JPP 20.3, Ph3P), H NMR: 2.2 (s, 1H, NH), 6.3–8.1
(m, 50H).
[19] F.H. Allen, O. Kennard, D.G. Watson, L. Brammer, A.G. Orpen,
R. Taylor, J. Chem. Soc. Perkin Trans. II. 12 (1987) 1.
[20] H. Schmidbaur, S. Lauteschlager, B. Milewski-Mahrla, J. Orga-
nomet. Chem. 254 (1983) 59.
4. Supplementary material
[21] D.D. Perrin, W.L.F. Armarego, D.R. Perrin, Purification of
Laboratory Chemicals, Pergamon, Oxford, 1980.
[22] H. Noth, L. Meinel, Z. Anorg. Allg. Chem. 349 (1967) 225.
[23] E. Upor, M. Mohai, Gy. Novak, Photometric Methods in
Inorganic Trace Analysis, Academiai Kiado, Budapest, 1985.
[24] Bruker, SAINTPLUS Data Reduction and Correction Program v.
6.02a, Bruker AXS, Madison, WI, USA, 2000.
The CIF are available from the Cambridge Crystallo-
graphic Data Center under the depositary numbers
259320 (4), 259321 (6), 259322 (7).
[25] G.M. Sheldrick, SADABS V.2.01, Bruker/siemens Area Detector
Absorption Correction Program, Bruker AXS, Madison, WI,
USA, 1998.
Acknowledgements
We are grateful to the Russian Foundation for Basic
Research (Grants 03-03-32051, 04-03-32830; scientific
[26] G.M. Sheldrick, SHELXTL V. 6.12, Structure Determination Soft-
ware Suite, Bruker AXS, Madison, WI, USA, 2000.