Rearrangement of phosphinohydrazide ligand -NPh-N(PPh2) 2 in transition metal coordination sphere: Synthesis and characterization of nickel and cobalt spirocyclic complexes M(NPh-PPh 2N-PPh2)2 and the

Article abstract of DOI:10.1016/j.jorganchem.2005.10.030

The reaction of diphosphinohydrazine PhNH-N(PPh₂)₂ (1) with cobalt(II) silylamide, Co[N(SiMe₃)₂]₂, proceeds via formation of unstable phosphinohydrazide complex Co[NPh-N(PPh ₂)₂]

Full text of DOI:10.1016/j.jorganchem.2005.10.030

Journal of Organometallic Chemistry 691 (2006) 879–889
www.elsevier.com/locate/jorganchem
Rearrangement of phosphinohydrazide ligand –NPh-N(PPh2)2
in transition metal coordination sphere: Synthesis and
characterization of nickel and cobalt spirocyclic complexes
M(NPh-PPh2@N-PPh2)2 and their properties
*
Vyacheslav V. Sushev, Alexander N. Kornev , Yuriy A. Minꢀko, Natalia V. Belina,
Yuriy A. Kurskiy, Olga V. Kuznetsova, Georgy K. Fukin, Evgenii V. Baranov,
Vladimir K. Cherkasov, Gleb A. Abakumov
Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences, 49 Tropinin Street, 603950 Nizhny Novgorod, Russia Federation
Received 1 September 2005; received in revised form 14 October 2005; accepted 21 October 2005
Available online 1 December 2005
Abstract
The reaction of diphosphinohydrazine PhNH-N(PPh2)2 (1) with cobalt(II) silylamide, Co[N(SiMe3)2]2, proceeds via formation of
unstable phosphinohydrazide complex Co[NPh-N(PPh2)2]2 followed by rearrangement to a new chelating compound Co(NPh-
PPh2@N-PPh2)2 (2). Disproportionation of nickel(I) silylamide, (Ph3P)2Ni-N(SiMe3)2, in the presence of 1, yields Ni(0) and Ni(II) phos-
phinoamide complexes: Ni[(Ph2P)2N-NPhH]2 (3), Ni(NPh-PPh2@N-PPh2)2 (4). X-ray analysis reveals tetrahedral environment of the
cobalt atom in 2 and square-planar environment of the nickel atom in cis-4. In contrast to the crystalline patterns, the solutions of 2
in THF or toluene have EPR signal which is typical to square-planar low-spin d7 cobalt complex. The reactions of 2 with dioxygen, ele-
mental sulfur and diphenyldiazomethane led to the spirocyclic insertion products Co(NPh-PPh2@N-PPh2@X)2 (X = O, S, NNCPh2)
while the absorption of carbon monoxide is reversible.
ꢀ 2005 Elsevier B.V. All rights reserved.
Keywords: Transition metal complexes; Cobalt; Nickel; Phosphazanes; Phosphinoamides; Phosphinohydrazines; Amidoimidophosphoranes; Phosphazane
rearrangements; X-ray diffraction
1. Introduction
reactions involving thermal rearrangements and transfor-
mations of phosphazane ligands in transition metal coordi-
nation sphere.
Compounds bearing a phosphorus–nitrogen bond have
attracted considerable attention both in heteroatom chem-
istry and as ligands for transition metals as well [1]. Phos-
phorus groups have been shown to form bonds with
nitrogen groups with relative ease, which is important for
ligand design and development of this branch of chemistry.
Another important circumstance is a wide gradation in
phosphorus–nitrogen bond energies inherent to different
class of compounds [1,2]. This makes possible template-like
Recently we have shown [3] that stability of the metal
complexes containing r-bonded phosphinohydrazide
ligand {–NPh-NPh-PPh2} is strongly dependent on the nat-
ure of the metal, its oxidation state and ligand environment.
Early and middle transition metals or non-transition metals
form stable phosphinohydrazides M[N(Ar)N(Ar)PPh2]n
{M = Li, Zn, Ge(II), Mn(II), Cr(III), Fe(II); Ar = Ph,
–C6H4But} while the late transition metals (Co, Ni, Cu)
and metals with enhanced oxidation state (Fe3+ in contrast
to Fe2+) cause transformation of phosphinohydrazide
ligand. The rearrangement of –NPh-NPh-PPh2 into
*
Corresponding author.
E-mail address: akornev@iomc.ras.ru (A.N. Kornev).
0022-328X/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.10.030

880
V.V. Sushev et al. / Journal of Organometallic Chemistry 691 (2006) 879–889
aminoiminophosphorane moiety, –NPh-PPh2@NPh, is
observed on Fe3+, Co2+, Ni2+ centers. The compound of
Ni(I), (Ph3P)2NiN(SiMe3)2, reacts with HNPh-NPh-PPh2
to form azobenzene complex, (Ph3P)2Ni(PhN@NPh), while
copper(I) silylamide affords diphenylphosphide {Ph2PCu}n
and azobenzene [3].
Comparing the acidity of 1 and hexamethyldisilazane it
may be assumed that both of them should not differ signif-
icantly from each other. Apparently, the driving force of
the reaction is initial coordination of the ligand to cobalt
atom which relieves the following substitution of
(Me3Si)2N– group.
In present paper we report another interesting findings
involving rearrangement of diphosphinohydrazide ligand
–NPh-N(PPh2)2 in coordination sphere of divalent cobalt
and nickel. The chemical properties of novel complexes will
be also considered.
It was impossible to isolate the originally formed phosp-
hazane complex Co[NPh-N(PPh2)2]2. The attempts to stop
the reaction at the initial period of time gave only intracta-
ble waxy solid, while maintaining the reaction mixture for
24 h affords excellent yield of 2 as dark-green crystals. Thus
the rearrangement of the ligand in cobalt(II) coordination
sphere is occurred. The process includes insertion of Ph2P–
group into nitrogen–nitrogen bond, which is accompanied
with the cycle extension.
2. Results and discussion
2.1. Synthesis of 1,1-bis(diphenylphosphino)-2-
phenylhydrazine, (Ph2P)2N-NH-Ph (1)
Ph2P
Ph2P
Ph
N
PPh2
NPh
N
N
Ph2P
Diphosphinohydrazine 1 was easily prepared by interac-
tion of phenylhydrazine hydrochloride with two equiva-
lents of chlorodiphenylphosphine in the presence of
triethylamine.
Bis(triphenylphosphine)nickel(I) bis(trimethylsilyl)amide
reacts with 1 in similar way, although this reaction is rather
more complicated (Eqs. (3), (4a)–(4d)).
2Ph2PCl þ PhNHNH2ðHClÞ þ 3Et3N
Et2O
!
ðPh2PÞ2N-NH-Ph ð95%Þ
ð1Þ
ꢀ3Et3NHCl
1
Ph2P
Ph2P
Ph
H
2(Ph3P)2NiN(SiMe3)2
+
4
N
N
Diphosphinohydrazine 1 is relatively air-stable and water-
resistant compound. It shows single resonance in 31P
NMR spectrum at d 70.5 ppm. Interestingly, 1H NMR
shows NH singlet at 5.84 ppm while NH group reveals very
weak absorption (3330 cmꢀ1) in IR spectrum.
1
Ph
P
Ph
P
PPh2
Ph
N
P
Ph
N
P
ð3Þ
Ni0
2
PhNH-N
+
Ni
Ph
Ph
2.2. Reactions of 1 with cobalt(II) bis(trimethylsilyl)amide,
and bis(triphenylphosphine)nickel(I)-
bis(trimethylsilylamide)
Ph
Ph
PPh2
N
N
3
Ph
Ph
4
+ 2(Me3Si)2NH + 4Ph3P
Cobalt silylamide, Co[N(SiMe3)2]2 reacts with two
equivalents of diphosphinohydrazine (1) in toluene solu-
tion under mild conditions for 24 h. Originally formed dark
violet color of the mixture turned green-brown during the
reaction time. We succeed to separate a single product of
this reaction in high yield, which is proved to be the com-
plex of phosphazene type (2) according to X-ray analysis.
Mixing of the starting compounds in toluene at room tem-
perature gave dark red-brown solution. Replacement of
toluene by diethyl ether affords air sensitive dark cerise
crystalline precipitate, which showed single resonance at
113.9 ppm in the 31P NMR spectrum. According to ele-
ment analysis, chemical behavior and NMR data we assign
this compound to the complex of zero valent nickel
Ni[(Ph2P)2N-NPhH]2 (3). Note, that 31P NMR monitoring
of the reaction mixture containing Ni(Ph3P)4 and ligand 1
in molar ratio 1:2 gave the same signal at 113.9 ppm (to-
gether with ꢀ4.0 ppm of Ph3P) which is additional evidence
of the complex 3 formation (Eq. 4b). The 31P NMR spec-
trum of remained reaction mixture showed two compli-
cated multiplets at 71.5 and 49.6 ppm. Heating of the
reaction mixture for 10 h at 40 ꢁC followed by removing
of the solvent yields orange crystals of 4. The compound
4 shows two triplets in 31P NMR spectrum with splitting
constant 17 Hz and chemical shifts at 72.1 and 50.6 ppm,
which were assigned to PIII and PV accordingly. The IR
spectrum of the crystals contains two strong absorptions
Ph
Ph2P
Ph2P
N-N
Co[N(SiMe3)2]2
+
2
H
1
Ph
ð2Þ
Ph
Ph
N
P
Ph
N
P
P
PhMe
-2 HN(SiMe3)2
(93%)
Ph
Co
Ph
N
P
N
Ph
Ph
Ph
Ph
2
The IR spectrum of the crystals differs significantly from
the spectrum of 1 and contains strong absorption at
1238 cmꢀ1 assigned to m(PV@N) bonds in phosphazenes [4].

V.V. Sushev et al. / Journal of Organometallic Chemistry 691 (2006) 879–889
881
at m 1270, 1250 cmꢀ1 assigned to (PV@N) bonds stretching
vibrations [4].
We tried to obtain 2 and 4 in another way, by interac-
tion of metal halides with lithium salt of 1. This method
however affords 2 and 4 in worse yields apparently because
of easy oxidation of diphosphinohydrazide ion [(Ph2P)2N-
NPh]ꢀ with metal salt. We noticed the appearance of bright
scarlet coloration of the reaction mixtures at the beginning
of the reagents mixing. The same bright scarlet coloration
we observed in the course of oxidation of (Ph2P)2N-
N(Li)Ph in THF solution with molecular oxygen. An
EPR spectrum reveals formation of a stable radical whose
odd electron localized on two phosphorus and two nitro-
gen atoms. Ai(P) = 6.50 G (2P), Ai(N) = 6.50 G (1N),
Ai(H) = 3.25 G (2H), Ai(H) = 1.00 G (2H), Ai(N) = 3.45 G
(1N); gi = 2.0049 (Fig. 1). The nature of spectra, however,
doesnꢀt allow to assign the last one to a certain structure.
Tentatively we propose formation of nitrogen centered rad-
ical like [(Ph2P)2N-Nꢀ-C6H4-X] where X is unknown group.
Fig. 2. Molecular structure of Co(NPh-PPh2@N-PPh2)2 (2). Phenyl rings
are omitted for clarity. Thermal ellipsoids are drawn at 30% probability.
containing two plane five-membered cycles CoNPNP
unfolded relatively to each other to 84.6ꢁ. The cobalt atom
has a distorted tetrahedral coordination. The bond angles
N(1)Co(1)P(2) and N(3)Co(1)P(4) are close to 90ꢁ
(89.33(5)ꢁ and 90.64(5)ꢁ), respectively (Table 2).
2.3. Structural description of M(NPh-PPh2@N-PPh2)2
M = Co (2), Ni (4) and mechanistic aspects of their
formation
The P–N bond lengths all lie between the values of
˚
˚
The X-ray diffraction study (Fig. 2) has shown that mol-
P–N single (1.77 A) and P@N double bonds (1.56 A) [5],
ecule 2 in the solid state represents the spirocyclic complex
as they occur in phosphazenes. The bonds P(1)–N(2)
1.584(2) A and P(3)–N(4) 1.588(2) A are mainly of double
bond character, whereas the distances P(1)–N(1), P(2)–
˚
˚
˚
N(2), P(3)–N(3) and P(4)–N(4) (1.632(2)–1.640(2) A)
correspond rather to bond lengths between single and
double bonds.
The nitrogen atoms N(1) and N(3) have near planar
geometry with the sum of the angles (358.58ꢁ and
359.42ꢁ). The Co(1)–P(2,4) and Co(1)–N(1,3) distances in
˚
˚
2 are 2.3376(6), 2.3164(6) A and 1.944(2), 1.987(2) A,
respectively. It is worth to cite an instance of related spiro-
cyclic cobalt(II) phosphazene complex Co[Ph2PNPPh2-
NPPh2]2 (5) [6,7], which can be considered as
a
N(1)-capped CoP4 tetrahedron or as a distorted tetragonal
pyramid with an apical P(3) and a N(1)–P(1)–P(4)–P(6)
base. The complex is in low-spin electronic state showing
l
eff = 2.39 lB. It should be noted that two Co–P distances
˚
in 5 (2.319, 2.342 A) are close to the analogues bond
lengths in 2 whereas two other Co–P(1) 2.217 A, and
Co–P(4) 2.206 A are significantly shorter.
˚
˚
P3
P6
P4
N4
N3
N2
P2
P5
Co
N1
P1
5
Interestingly, while the crystalline sample of 2 has no
EPR signal (on account of high spin d7 state of cobalt), dis-
solution of 2 in THF or toluene is accompanied with
Fig. 1. EPR signal arising by oxidation of [(Ph2P)2N-NPh]ꢀ with O2.
(a) in THF at 290 K and simulation of [(Ph2P)2N-Nꢀ-C6H4-X] EPR
spectrum (b).

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V.V. Sushev et al. / Journal of Organometallic Chemistry 691 (2006) 879–889
appearance of EPR signal (gi = 2.256) indicating the local-
ization of odd electron on the metal. At low temperature
(145 K) the complex exhibits anisotropic EPR spectrum
with g-tensor close to axial (g1 = 2.0091, g2 = 2.313,
g3 = 2.407) (Fig. 3). Such spectrum is typical to the
square-planar low-spin d7 cobalt complexes [8].
tion. Selected bond distances and angles for 4 are given
in Table 2. The Ni–P bond length of 2.1604(4) and
˚
2.1618(4) A are within the normal range observed for
Ni(II) chelate complexes [3,9]. Meanwhile these distances
are substantially shorter then Co–P ones {2.3164(6) and
˚
2.3376(6) A} in 2. Apparently this fact together with tense
Analogous nickel phosphazene complex 4 is diamag-
netic. Nickel atom has square-planar environment. The
crystal structure (Fig. 4) reveals formation of cis-4 which
is much more sterically hindered than the possible trans-
isomer. The crystal structure consists of discrete molecules
of 4 and a toluene molecule which has no shortened
contacts with 4 and may be considered as a solvation
molecule. Heterocycles Ni(1)–P(1)–N(1)–P(2)–N(2) and
Ni(1)–N(3)–P(3)–N(4)–P(4), are non-planar contrary to
2, so the spirocyclic molecule adopt chair-like conforma-
conformation of cis-isomer may cause NiNPNP-ring
strain and its puckered conformation. In addition note
that valent angles at phosphazene nitrogen atoms in 4
{P(3)–N(4)–P(4), P(2)–N(1)–P(1) both approx. 112ꢁ} are
far less than those ones found for related cobalt complex
2 {P(3)–N(4)–P(4), P(1)–N(2)–P(2) both approx. 120ꢁ}.
The N–P bond distances in 4 are in the range 1.60–
˚
1.63 A that is more justified as compared to analogous
cobalt complex 2.
The angles N(2)–Ni(1)–P(1) and N(3)–Ni(1)–P(4) are
both 82.72ꢁ. Nitrogen atoms N(2) and N(3) have a trigo-
nal-planar environment. Phenyl groups at these nitrogen
atoms lie on each side of the plane N(2)N(3)Ni(1)P(4)P(1)
apparently due to significant steric hindrances.
Formation of cis-4 takes about 3 days at 20 ꢁC or heat-
ing for 10 h at 40–50 ꢁC. We did not find any traces of
trans-4 in the reaction mixture. Considering mechanistic
aspects of the reaction we exclude formation of intermedi-
ate monovalent nickel species since (a) there are no EPR
signal were registered in the course of the reaction; (b) it
is known that small chelate angle at nickel atom is unfavor-
able for existence and formation of Ni(I) complexes [10].
On the other hand, as we realized earlier [9], nickel(I) sily-
lamide is prone to disproportionation in the presence of
phosphines.
Ph3P
Ni
ð4aÞ
N(SiMe3)2
Ph2P
(Ph3P)4Ni + {Ni[N(SiMe3)2]2}
Ph3P
Ph
H
Fig. 3. EPR spectrum of Co(NPh-PPh2@N-PPh2)2 (2) at 145 K.
N
(Ph3P)4Ni +
2
N
Ph2P
1
PPh2
ð4bÞ
Ni0 + 4 Ph3P
2
PhNH-N
PPh2
3
Ph
N
Ph2P
Ph2P
N
{Ni[N(SiMe3)2]2} +
H
-(Me3Si)2NH
1
Ph2P
Ph2P
ð4cÞ
N
N(SiMe3)2
Ni
Ni N(SiMe3)2
Ph2P
N
Ph2P
N
N
Ph
Ph
It is well documented that phosphino groups show stron-
ger trans influence in contrast with amino-substituents
[11]. Since the addition of diphosphinohydrazine ligands
proceeds consecutively, coordination of Ph2P-group of
the second molecule is directed to more favorable cis-
position.
Fig. 4. Molecular structure of Ni(NPh-PPh2@N-PPh2)2 (4). Phenyl rings
are omitted for clarity. Thermal ellipsoids are drawn at 30% probability.

V.V. Sushev et al. / Journal of Organometallic Chemistry 691 (2006) 879–889
883
singlets in 31P NMR spectrum at 16.3 and 11.7 ppm. There
are several strong absorption bands in the IR spectrum of 7
is observed in the region 1300–1180, 1165 cmꢀ1 which are
indicative of the presence of P@N and P@O bonds in the
molecule. The X-ray investigation shows formation of free
amido-phosphinoxide ligand PhNH-PPh2@N-PPh2@O (7),
which is dimer in the solid state located on the inversion
center. (Fig. 5). The crystal structure consists also a mole-
cule of diethyl ether which has no shortened contacts with 7
and may be considered as a solvation molecule. The
Ph2P
Ph2P
N
PPh2
N
Ph2P
Ni
Ph2P
N
N
H
Ph
1
Ni
N PPh2
-(Me Si) NH
Ph2P
3
2
Ph2P
N
N
N
N(SiMe3)2
Ph
Ph
Ph
Ph2P
PPh2
N
N
Ni
Ph2P
PPh2
N
N
˚
H(1A). . .O(1B) (1.93(4) A) distance is significantly shorter
Ph
Ph
4
of the geometrical criterion for the formation of hydrogen
˚
˚
ð4dÞ
bonds (2.15 A [14]) and the N(1A). . .O(1B) (2.754(5) A)
distance is close to the value of typical van-der-waals con-
Note that most of known relative square-planar nickel(II)
complexes with N,P-chelate ligands, e.g., {Ni[Ph2PCH2-
PPh2@NH]2}2+ [12], [Ni(Me2PCH2CH2NH2)2]Cl2 [13] have
also cis-conformation.
˚
tact between O and N atoms (2.78 A [14]). The bond
N(1A)H(1A)O(1B) angle is 169.2ꢁ. The distribution of
the bond lengths in the P(1)N(2)P(2)N(1) framework indi-
˚
cates one formally double P(2)–N(2) bond (1.557(4) A) and
˚
two single bonds N(1)–P(2) (1.641(4) A), N(2)–P(1)
2.4. Chemical properties
˚
1.597(4) A. The last one is contracted significantly
apparently due to strong positive charge on P(1) atom
One of the remarkable properties of the amidophos-
phine complexes 2 and 4 is their high resistance to hydro-
lysis in neutral and alkaline medium. This is rather
exception in the chemistry of metal amides, but may be
explained with strong chelation and charge redistribution
along the conjugated N–P bonds. Strong acids (e.g., aque-
ous HCl) destroy the compounds. Phosphazene nickel
complex 4 turned out to be quite inert also to atmospheric
oxygen and carbon monoxide. Interaction of 4 with carbon
monoxide in toluene solution at ambient temperature and
pressure proceed slowly, for several days and gave no iso-
lable products. On the other hand, cobalt complex 2
showed an interesting chemistry.
(–Ph2P+–Oꢀ). It should be noted that the P(1)–O(1)
˚
˚
(1.489(3) A) distance is a typical for the P@O (1.489 A
[15]) bonds.
We cleared up the composition of 6 by the back synthe-
sis. Addition of 7 to cobalt silylamide, Co[N(SiMe3)2]2, in
stoichiometric amount immediately gave blue complex 6
as can be judged on visible and IR spectra (see Section 3).
2.4.2. Interaction of 2 with elemental sulfur
Complex 2 being sensitive to electrophilic oxidation,
easily reacts with elemental sulfur. Heating of toluene solu-
tion of 2 with two equivalents of sulfur at 40 ꢁC for 30 min
yields dark blue solution. Concentration and maintaining
of the solution at 20 ꢁC overnight gave blue-violet crystals
of the complex 8, which is formed by insertion of sulfur
into both Co–P bonds.
2.4.1. Interaction of 2 with dioxygen
Being quite stable to hydrolysis, 2 is oxidized easily with
dioxygen to form insertion product 6 in quantitative yield.
O
N
P
O
P
P
P
P
N
P
N
P
+ O2
N
Co
N
Co
20oC, 1min
P
N
N
N
6
2
ð5Þ
Dark green solution of 2 in THF or toluene turned light
blue after short contact with dry oxygen.
Replacement of THF for diethyl ether gave moisture
sensitive blue crystals of 6. The complex 6 shows strong
absorption in the IR spectrum at 1270, 1235, 1210 and
1178 cmꢀ1 which evidences on the presence of P@N and
P@O bonds in the molecule.
Maintaining of ether solution of 6 for 3–5 h in air
affords abundant colorless crystalline precipitate 7. The
same precipitate is formed immediately after addition of
small quantities of water. The substance showed two wide
Fig. 5. Molecular structure of PhNH-PPh2@N-PPh2@O (7). Phenyl rings
are omitted for clarity. Thermal ellipsoids are drawn at 30 % probability.

884
V.V. Sushev et al. / Journal of Organometallic Chemistry 691 (2006) 879–889
the rate of gas diffusion into a solution. The green color
P
P
S
P
S
P
P
of the solution assumed yellow tint. The electronic
spectrum showed fast disappearance of absorption bands
of the initial complex (k, nm: 503, 603, 686) while new
broad absorption at 735 nm arose. IR spectrum revealed
strong band at 1975 cmꢀ1 (a special experiment in
CHCl3), indicating formation of carbonyl cobalt
complex.
The hyperfine coupling constant with phosphorus
nucleus a(31P) is known is sensitive to the coordination
geometry. EPR spectrum of the reaction mixture (Fig. 7)
showed appearance of novel doublet Ap = 140 G and addi-
tional hyperfine coupling A = 27 G (gi = 2.088). Appar-
ently, coordination of carbon monoxide to cobalt atom
changes the geometry of the complex to tetragonal pyramid
(10):
N
N
P
+ 1/4S8
40oC, 30 min
N
Co
N
Co
P
P
N
N
N
N
8
2
ð6Þ
IR spectrum of 8 contains very strong absorptions at 1191,
1175 and 578 cmꢀ1 referred to stretching vibrations of
P@N and P@S fragments, respectively. The X-ray investi-
gation reveals the formation of spirocyclic complex with
central cobalt atom in tetrahedral environment. The six-
member cycles are non-planar.
The P–N distances in 8 are greatly justified. So formally
double bonds (P(2)–N(1), P(4)–N(3)) and single bonds
(P(1)–N(1), P(3)–N(3)) are 1.592(2), 1.590(1) A and
1.599(1), 1.590(2) A, respectively. The P(2)–N(2) and
P(4)–N(4) bonds at r-bonded nitrogen atoms, bearing neg-
ative charge, are significantly longer (1.631(2) and
1.637(1) A, respectively). The Co–N bond distances in 8
(1.985(1) and 2.002(1) A) are also longer than in a relative
complex 2 (1.944(2) and 1.987(7) A). That may be explain
rather weaker chelating effect of the ligand –NPh-
PPh2@N-PPh2@S in 8 as compared to –NPh-PPh2@N-
PPh2 ligand in 2. The Co(1)–S(1) (2.3676(5) A) and
Co(1)–S(2) (2.3525(5) A) distances vary in the typical range
of the coordination P@S ! Co bonds [16] (Fig. 6).
The complex 8 like 6 is also easily hydrolysable in ether
solution to form free ligand HNPh-PPh2@N-PPh2@S (9) in
quantitative yield as stable colorless crystals. The 31P NMR
spectrum of 9 contains two wide singlets at 44.2 and
17.2 ppm while IR spectrum reveals strong absorptions at
1253, 1226, 1175 and 600 cmꢀ1 characterizing P@N and
P@S stretching vibrations accordingly.
˚
˚
Ph
Ph
Ph
Ph
N
P
P
N
P
Ph
Ph
˚
Co
P
Ph
˚
N
N
˚
Ph
Ph
Ph
2
ð7Þ
O
C
Ph
Ph
P
˚
Ph
Ph
˚
+ CO
P
N
N
Co
Ph
Ph
Ph
P
vacuum
P
N
N
Ph
Ph
Ph
10
The coordination of carbon monoxide to cobalt atom in 2
is reversible. Solvent removal in vacuum led to the starting
compound 2 as we can judge on EPR, electronic and IR
spectra.
2.4.3. Interaction of 2 with CO
A solution of 2 in toluene absorbs carbon monoxide
at atmospheric pressure and ambient temperature with
2.4.4. Interaction of 2 with diphenyldiazomethane
In a related reaction we tested the ability of 2 to inter-
cept a diphenylcarbene unit from Ph2CN2. Rather than
undergoing carbene transfer and concomitant expulsion
of N2 we found that the reaction of 2 with two equivalents
of Ph2CN2 proceeds by insertion of the last one into phos-
phorus–cobalt coordination bond.
Ph2C
N
N
P
N
P
Ph2C=N=N
2
N
Co
N
ð8Þ
P
N
N
P
N
11
CPh2
We failed to separate 11 in crystalline form. Nonetheless, in
the course of several attempts of crystallizations we ob-
tained blue-violet crystals of related complex 12, which
turn out to be a product of partial hydrolysis of 11.
Fig. 6. Molecular structure of Co(NPh-PPh2@N-PPh2@S)2 (8). Thermal
ellipsoids are drawn at 30% probability.

V.V. Sushev et al. / Journal of Organometallic Chemistry 691 (2006) 879–889
885
Fig. 7. EPR spectra of the reaction mixture 2 + CO in toluene solution at different temperature.
Ph2C
P
metal centers. Each cobalt center is coordinated to two
(amido and amino) nitrogen atoms of the ligand and two
bridging hydroxy groups. Hence, each cobalt center is
four-coordinate, with distorted tetrahedral geometry. The
core Co2O2 of the molecule is flat. The inside angles OCoO
and CoOCo are 81.18(5)ꢁ and of 98.82(5)ꢁ, respectively.
Each six-membered cycle (CoNPNPN) adopts a boat con-
formation. Complex 12 indicates an interesting distribution
of the bond lengths N–P in the NPNPN framework. There
are no distinct alternate single and double P. . .N bonds in
N
N
H
O
N
P
2H2O
N
2 mol of 11
Co
Co
+
N
O
H
P
N
N
P
ð9Þ
N
12
CPh2
+ 2 PhNH-PPh2=N-PPh2=N-N=CPh2
13
IR spectrum of 12 contains strong absorption bands at
1265, 1205, 1115 cmꢀ1 characterizing P@N double bonds
and sharp absorption at 3680 cmꢀ1 which is indicative of
bridge OH group appearance. As we found, the complex
12 has no signals in 31P NMR spectrum apparently due
to paramagnetic nature. Meanwhile, mother liquor shows
two doublets at 20.8 and 4.3 ppm (JP,P = 4.7 Hz) which
may be attributed to a free ligand 13 being formed as a sec-
ond product during hydrolysis of 11. Keeping of 13 in
mother liquor in open air for two weeks results in its oxida-
tion to form phosphinoxide 7 as we may judge by 31P
NMR measurements and IR spectrum of colorless crystal-
line precipitate.
The molecular structure of 12 is illustrated in Fig. 8,
while details of the X-ray analysis and selected bond
lengths and angles are listed in Tables 1 and 2, respectively.
The molecule 12 is a centrosymmetric OH-bridged dimer in
the solid state. The crystal structure consists of discrete
molecules of 12 and four toluene molecules which have
no shortened contacts with 12 and may be considered as
a
solvation molecules. The Co–Co distance of
Fig. 8. Molecular structure of [Co(NPh-PPh2@N-PPh2@N-N@CPh2)2]2-
(l-OH)2 (12). Thermal ellipsoids are drawn at 30% probability.
˚
2.9682(4) A precludes bonding interactions between the

886
V.V. Sushev et al. / Journal of Organometallic Chemistry 691 (2006) 879–889
Table 1
The details of crystallographic, collection and refinement data for 2, 4, 7, 8 and 12
2
4
7
8
12
Empirical formula
Formula weight
Temperature (K)
Crystal system
Space group
C60H50CoN4P4
1009.85
100
C67H58N4NiP4
1101.76
293
Monoclinic
C2/c
45.393(2)
13.8295(6)
18.7768(8)
C34H36N2O2P2
566.59
100(2)
Monoclinic
P2(1)/c
12.628(4)
21.195(7)
12.479(4)
C60H50CoN4P4S2
1073.97
100(2)
C114H104Co2N8O2P4
1859.79
100(2)
Triclinic
Triclinic
Triclinic
ꢀ
ꢀ
ꢀ
P1
P1
P1
˚
a (A)
11.092(1)
13.037(1)
18.216(2)
92.575(2)
105.855(2)
100.540(2)
2478.6(4)
2
12.7950(6)
13.5669(6)
16.2243(7)
88.993(1)
80.666(1)
71.040(10)
2626.4(2)
2
13.5167(8)
13.8168(8)
15.8448(9)
91.233(1)
111.859(1)
115.862(1)
2410.6(2)
1
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
106.024(1)
117.647(8)
3
˚
Volume (A )
11329.3(8)
8
1.292
0.501
4608
2959(2)
4
1.272
0.181
Z
Density (calculated) (g/cm3)
Absorption coefficient (mmꢀ1
F(000)
1.353
0.520
1050
1.358
0.572
1114
1.281
0.467
974
)
1200
Crystal size (mm)
hmax range for data collection (ꢁ)
Index ranges
0.40 · 0.20 · 0.15
25.00
ꢀ13 6 h 6 13
ꢀ15 6 k 6 15
ꢀ21 6 l 6 21
19591
0.3 · 0.20 · 0.10
29.03
ꢀ61 6 h 6 61
ꢀ18 6 k 6 18
ꢀ25 6 l 6 25
59065
0.05 · 0.05 · 0.01
23.32
ꢀ14 6 h 6 14
ꢀ23 6 k 6 16
ꢀ13 6 l 6 12
13727
0.61 · 0.17 · 0.14
24.00
ꢀ14 6 h 6 13
ꢀ11 6 k 6 15
ꢀ18 6 l 6 17
13373
0.30 · 0.16 · 0.12
25.00
ꢀ16 6 h 6 16
ꢀ12 6 k 6 16
ꢀ14 6 l 6 18
13352
Reflections collected
Independent reflections
Absorption correction
Max/min transmission
Refinement method
8691 [Rint = 0.0241] 15048 [Rint = 0.0333] 4277 [Rint = 0.1024] 8224 [Rint = 0.0164] 8456 [Rint = 0.0227]
SADABS
0.9260/0.8189
0.9516/0.8642
0.9982/0.9910
0.9242/0.7216
0.9461/0.8726
Full-matrix least-squares on F2
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2sigma(I)]
8691/0/822
1.057
15048/20/919
1.021
4277/0/465
0.989
8224/0/840
1.043
8456/31/826
0.997
R1 = 0.0339
wR2 = 0.0820
R1 = 0.0427
wR2 = 0.0847
0.458/ꢀ0.235
R1 = 0.0440
wR2 = 0.1060
R1 = 0.0710
wR2 = 0.1208
0.538/ꢀ0.254
R1 = 0.0638
wR2 = 0.1418
R1 = 0.1250
wR2 = 0.1708
0.709/ꢀ0.384
R1 = 0.0325
wR2 = 0.0819
R1 = 0.0407
wR2 = 0.0849
0.449/ꢀ0.192
R1 = 0.0398
wR2 = 0.0933
R1 = 0.0569
wR2 = 0.0993
0.492/ꢀ0.234
R indices (all data)
ꢀ3
˚
Largest diff. peak and hole (e A
)
the cycles as depicted in graphic formula of 12. Instead,
to elemental analysis only one molecule of H2S was
absorbed per cobalt atom of 2. IR spectrum shows no
SH bonds in the region 2400–2500 cmꢀ1, instead absorp-
tion of NH bond is appeared at 3210 cmꢀ1. General view
of the spectrum reveals similarity to IR spectra of the
ligand PhNH-PPh2@N-PPh2@S. However no 31P NMR
spectrum was registered probably due to paramagnetism
of the complex. The H2S-adduct was found to be suffi-
ciently less oxygen sensitive as compared to starting com-
plex 2. However, keeping of the THF solution of
(2 Æ H2S) overnight in contact with air affords colorless
crystals of PhNH-PPh2@N-PPh2@O (7) according to IR
and 31P NMR spectra. It means that hydrogen disulfide
does not destroy the phosphazene ligand when interact
with 2. Unfortunately, we failed to obtain (2 Æ H2S) in crys-
talline form, suitable for X-ray analysis. Tentatively the
complex was formulated as phosphino-sulfide [(HNPh-
PPh2@N-PPh2)2CoS]n.
two terminal bonds P(1)–N(1) and P(2)–N(3) (1.6205(14)
˚
and 1.6390(15) A, respectively) are elongated relatively of
two middle bonds P(1)–N(2) and P(2)–N2 (1.5954(11)
˚
and 1.5889(13) A, respectively). This suggests more nega-
tive charge location on N(1) and N(3) atoms coordinated
to cobalt. The Co–N bond distances in 12 (2.029(1) and
˚
2.037(1) A) are slightly longer than in a relative complexes
2 and 8 that may be explain rather weaker chelating effect
of the ligand –NPh-PPh2@N-PPh2@N-N@CPh2.
Discussing the mechanistic aspects of Ph2CN2 insertion
into Co–P coordination bond, we suggest initial coordina-
tion of terminal nitrogen to cobalt atom to form g1-bonded
complex. It is known an example of such complexation in
the reaction of diphenyldiazomethane with Co(I) complex
PhB(CH2PPh2)3Co(PMe3) [17]. The resulting compound
{PhB(CH2PPh2)3CoNNCPh2} exhibits high thermal and
photo stability.
2.4.5. Interaction of 2 with H2S
3. Experimental
Using the reaction of 2 with H2S we attempted to sepa-
rate free ligand HNPh-PPh2@N-PPh2 from the metal. The
interaction of 2 and H2S in THF proceed fast to form dark-
brown solution. Single strong absorption band at
3.1. General considerations
Solvents were purified following standard methods [18].
Toluene and methylene chloride were thoroughly dried and
k
max = 430 nm is observed in electron spectrum. According

V.V. Sushev et al. / Journal of Organometallic Chemistry 691 (2006) 879–889
887
Table 2
The selected distances (A) and angles (ꢁ) for 2, 4, 7, 8 and 12
˚
Co(NPh-PPh2@N-PPh2)2 (2)
Ni(NPh-PPh2@N-PPh2)2 (4)
PhNH-PPh2@N-PPh2@O (7)
Co(NPh-PPh2@N-PPh2@S)2
(8)
[Co(NPh-PPh2@N-PPh2@
N-N@CPh2)2]2(l-OH)2 (12)
˚
Bond distance (A)
Co(1)–N(1)
Co(1)–N(3)
Co(1)–P(4)
Co(1)–P(2)
P(1)–N(2)
P(1)–N(1)
P(2)–N(2)
P(3)–N(4)
P(3)–N(3)
P(4)–N(4)
1.944(2)
Ni(1)–N(2)
Ni(1)–N(3)
Ni(1)–P(1)
Ni(1)–P(4)
P(1)–N(1)
N(1)–P(2)
P(2)–N(2)
P(3)–N(4)
P(3)–N(3)
P(4)–N(4)
1.986(1)
P(1)–O(1)
1.489(3)
1.597(4)
1.557(4)
1.641(4)
1.93(4)
Co(1)–N(2)
Co(1)–N(4)
Co(1)–S(2)
Co(1)–S(1)
S(1)–P(1)
1.985(1)
Co(1)–O(1)
Co(1)–O(1)#1
Co(1)–N(1)
Co(1)–N(3)
Co(1)–Co(1)#1
P(1)–N(2)
1.949(1)
1.959(1)
2.029(1)
2.037(1)
2.968(1)
1.595(1)
1.621(1)
1.589(1)
1.639(1)
1.410(2)
1.398(2)
1.987(2)
2.316(1)
2.338(1)
1.584(2)
1.632(2)
1.638(2)
1.588(2)
1.640(2)
1.635(2)
1.987(1)
2.160(1)
2.162(1)
1.633(1)
1.598(1)
1.620(1)
1.599(1)
1.628(1)
1.628(1)
P(1)–N(2)
2.002(1)
2.353(1)
2.368(1)
2.010(1)
2.015(1)
1.599(1)
1.592(1)
1.631(1)
1.590(2)
1.590(1)
1.637(1)
N(2)–P(2)
P(2)–N(1)
H(1). . .O(1)#1
N(1). . .O(1)#1
2.754(5)
S(2)–P(3)
P(1)–N(1)
P(2)–N(1)
P(2)–N(2)
P(3)–N(3)
P(4)–N(3)
P(4)–N(4)
P(1)–N(1)
P(2)–N(2)
P(2)–N(3)
N(1)–C(1)
N(3)–N(4)
Bond angles (ꢁ)
N(1)–Co(1)–N(3)
N(1)–Co(1)–P(4)
N(3)–Co(1)–P(4)
N(1)–Co(1)–P(2)
N(3)–Co(1)–P(2)
P(4)–Co(1)–P(2)
N(2)–P(1)–N(1)
N(2)–P(2)–Co(1)
N(4)–P(3)–N(3)
N(4)–P(4)–Co(1)
C(1)–N(1)–P(1)
C(1)–N(1)–Co(1)
P(1)–N(1)–Co(1)
P(1)–N(2)–P(2)
C(31)–N(3)–P(3)
C(31)–N(3)–Co(1)
P(3)–N(3)–Co(1)
P(3)–N(4)–P(4)
122.53(7)
114.30(5)
90.64(5)
89.33(5)
119.41(5)
123.84(2)
112.21(9)
100.99(6)
113.58(9)
101.76(6)
120.5(1)
122.1(1)
116.0(1)
119.9(1)
123.3(1)
122.5(1)
113.7(1)
120.2(1)
N(2)–Ni(1)–N(3)
N(2)–Ni(1)–P(1)
N(3)–Ni(1)–P(1)
N(2)–Ni(1)–P(4)
N(3)–Ni(1)–P(4)
P(1)–Ni(1)–P(4)
N(1)–P(1)–Ni(1)
N(1)–P(1)–P(2)
P(2)–N(1)–P(1)
N(1)–P(2)–N(2)
P(2)–N(2)–Ni(1)
N(4)–P(3)–N(3)
P(3)–N(3)–Ni(1)
N(4)–P(4)–Ni(1)
P(3)–N(4)–P(4)
94.46(5)
82.72(4)
O(1)–P(1)–N(2)
P(2)–N(2)–P(1)
N(2)–P(2)–N(1)
N(1)–H(1)–O(1)
119.3(2)
N(2)–Co(1)–N(4)
N(2)–Co(1)–S(2)
N(4)–Co(1)–S(2)
N(2)–Co(1)–S(1)
N(4)–Co(1)–S(1)
S(2)–Co(1)–S(1)
P(1)–S(1)–Co(1)
P(3)–S(2)–Co(1)
N(1)–P(1)–S(1)
N(1)–P(2)–N(2)
N(3)–P(3)–S(2)
N(3)–P(4)–N(4)
P(2)–N(1)–P(1)
P(2)–N(2)–Co(1)
P(3)–N(3)–P(4)
P(4)–N(4)–Co(1)
116.16(6)
107.02(4)
107.16(4)
106.86(4)
104.24(4)
115.77(2)
101.06(2)
101.19(2)
117.39(6)
113.50(7)
117.14(5)
115.04(8)
126.14(9)
119.63(8)
127.21(9)
117.39(8)
O(1)–Co(1)–O(1)#1
O(1)–Co(1)–N(1)
O(1)#1–Co(1)–N(1)
O(1)–Co(1)–N(3)
O(1)#1–Co(1)–N(3)
N(1)–Co(1)–N(3)
N(2)–P(1)–N(1)
N(2)–P(2)–N(3)
Co(1)O(1)Co(1)#1
C(1)–N(1)–P(1)
81.18(5)
119.35(5)
117.65(5)
113.89(4)
119.93(5)
104.48(5)
109.36(7)
108.32(7)
98.82(5)
123.2(1)
127.0(1)
109.1(1)
129.0(1)
109.7(1)
135.7(1)
107.5(1)
119.9(1)
126.1(2)
139.8(3)
119.5(2)
169.2(4)
175.69(4)
175.42(4)
82.72(3)
100.29(2)
105.39(5)
33.60(5)
111.95(8)
108.74(6)
114.58(6)
108.87(6)
112.44(6)
105.43(5)
112.29(8)
C(1)–N(1)–Co(1)
P(1)–N(1)–Co(1)
P(2)–N(2)–P(1)
N(4)–N(3)–P(2)
N(4)–N(3)–Co(1)
P(2)–N(3)–Co(1)
C(37)–N(4)–N()
N(4)–C(37)–C(38)
distilled over P2O5 prior to use. Ether and THF were dried
and distilled over Na/benzophenone.
3.2. X-ray structure determinations
Metal silylamides Co[N(SiMe3)2]2 [19,20], (Ph3P)2NiN-
(SiMe3)2 [21] were prepared according to known methods.
All manipulations were performed with rigorous exclusion
of oxygen and moisture, in vacuum or under an argon
atmosphere using standard Schlenk techniques.
A summary of crystal data collection and refinement
parameters for 2, 4, 7, 8 and 12 are given in Table 1. The data
were collected on a Bruker AXS ‘‘SMART APEX’’ diffrac-
tometer (graphite-monochromated, Mo Ka-radiation,
˚
u–x-scan technique, k = 0.71073 A). The intensity data
Hexamethyldisilazane liberated in the course of the
metal silylamides reactions was detected by gas chromatog-
raphy analyses with Tsvet-500 device, equipped with stain-
less steel columns 0.4 cm · 200 cm, packed with 5% SE-30
on Chromatone N-Super, with a thermoconductivity detec-
tor and with helium as carrier gas.
Spectrophotometric determination of the metals (Co
and Ni) in the prepared compounds was provided by the
methods described in [22].
were integrated in the SAINT program [23]. SADABS [24] was
used to perform area-detector scaling and absorption correc-
tions. The structures were solved by direct methods and were
refined on F2 using all reflections with SHELXTL package [25].
All non-hydrogen atoms were refined anisotropically. The
hydrogen atoms in all complexes were found from Fourier
synthesis and refined isotropically except for H atoms in sol-
vate molecules in 4 (toluene), 7 (diethyl ether) and 12 (tolu-
ene), which were placed in calculated positions and refined
in the ‘‘riding-model’’. The details of crystallographic, col-
lection and refinement data are shown in the Table 1. The
selected distances and bond angles are listed in Table 2.
CCDC-282024 (2), 282025 (4), 282026 (7), 282027 (8)
and 282028 (12) contain the supplementary crystallo-
graphic data for this paper. These data can be obtained free
of charge at www.ccdc.cam.ac.uk/const/retrieving.html[or
from the Cambridge Crystallographic Data Centre, 12
Union Road, Cambridge CB2 1EZ, UK; fax: (internat.)
+44 1223/336 033; deposit@ccdc.cam.ac.uk].
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. EPR spectra were
recorded on a Bruker ER 200 D-SRC spectrometer with
ER041 MR microwave bridge, ER 4105 DR double reso-
nator and ER 4111 VT variable temperature unite. The
spectra were simulated using WinEPR SimFonia v1.25
(Bruker) by iteration of the (an)isotropic g values, hyper-
fine coupling constants, and line widths.

888
V.V. Sushev et al. / Journal of Organometallic Chemistry 691 (2006) 879–889
3.3. Synthesis
The mother liquor was heated at 40 ꢁC for 10 h then
kept for 3 days at 20 ꢁC. The second batch of crystals pre-
cipitated. The product was recrystallized from warm ether
affords orange crystals. Yield of Ni(NPh-PPh2@N-PPh2)2
(4) 0.62 g, (82%). Anal. calc. for C60H50P4N4Ni (4), %: C,
71.37; H, 4.99; Ni, 5.81. Found, %: C, 71.42; H, 5.14; Ni,
5.90. IR (cmꢀ1): 1270 (m), 1250 (m), 1160 (w), 1100 (vs),
1080 (vs), 970 (s), 830 (m), 800 (m), 750 (m), 700 (s), 620
(m), 550 (w), 520 (m). 31P{1H} NMR (CDCl3), d 72.1 (PIII,
3.3.1. (Ph2P)2N-NH-Ph (1)
An excess of triethylamine (5.05 g, 50 mmol) was added
to a mixture of fine crystalline PhNHNH2(HCl) (1.44 g,
10 mmol) and chlorodiphenylphosphine (4.41 g, 20 mmol)
in 60 mL of diethyl ether. The mixture was stirred for
12 h at 20 ꢁC then washed two times with water. Ether
solution was dried over anhydrous Na2SO4, the major part
of the solvent was removed in vacuum. A slow crystalliza-
tion at 20 ꢁC was completed in about 5 h to leave colorless
crystals of 1. Yield: 4.38 g (92%). Anal. calc. for
C30H26P2N2, %: C, 75.62; I, 5.50; P, 13.00. Found, %: C,
75.90; I, 5.38; P, 13.11. 31P{1H} NMR (CDCl3) d (ppm):
2
3
t, AA0); 50.6 (PV, t, XX0); JAX
+ JAX = 17 Hz.
0
3.3.4. Co(NPh-PPh2@N-PPh2@O)2 (6)
(A). A dry air was allowed to contact with ether solution
of 2. Green color of the solution immediately turns blue.
Cooling of the solution up to 0 ꢁC results in formation of
blue fine crystalline precipitate of 6 in quantitative yield.
Anal. calc. for C60H50P4N4O2Co, %: C, 69.17; H, 4.84;
Co, 5.66. Found, %: C, 69.10; H, 4.89; Co, 5.73. Electronic
(vis) spectrum (toluene) k, nm (e): 530 (80), 600 (200), 629
(40). IR (cmꢀ1): 1587 (m), 1285 (sh), 1270 (s), 1235 (vs),
1210 (vs), 1178 (m), 1121 (vs), 1077 (m), 1058 (vs), 1027
(m), 988 (w), 973 (s), 950 (w), 900 (m), 815 (m), 800 (sh),
750 (s), 725 (s), 695 (vs), 625 (w), 565 (s), 550 (s), 540
(sh), 525 (w), 510 (m).
(B). A solution of HNPh-PPh2@N-PPh2@O (7) (0.21 g,
0.5 mmol) in 10 ml of ether was added to a solution of
Co[N(SiMe3)2]2 (0,095 g, 0.25 mmol) in the same solvent
(5 mL). The mixture immediately turned blue. The mixture
was maintained at 20 ꢁC for 1 h. Solvent and hexamethyl-
disilazane were pumped in vacuum to leave blue crystals
of 6 with analytical data described above. Yield 0.21 g
(95%).
1
70.5 ppm. H NMR d (ppm): 7.70–7,15 (m, 20H, Ph2P),
7.10–6.40 (m, 5H, PhN), 5.84 (s, 1H, NH); IR (Nujol), m,
cmꢀ1: 3330 (ww), (NH), 1600 (m), 1430 (m), 1330 (w),
1300 (m), 1240 (m), 1170 (w), 1150 (w), 1080 (s), 1020
(m), 890 (vs), 830 (m), 745 (vs), 700 (vs), 530 (w), 510
(ww), 480 (m). T decomp. 150 ꢁC.
3.3.2. Co(NPh-PPh2@N-PPh2)2 (2)
A mixture of toluene solutions of (1) (0,95 g, 2 mmol,
20 mL) and Co[N(SiMe3)2]2 (0,38 g, 1 mmol, 10 mL) was
maintained at 20 ꢁC for 24 h. Toluene was pumped in vac-
uum and changed for ether (10 ml). Dichroic dark-green
crystals of 2 formed overnight were filtered, washed with
cold ether and dried in vacuum. Yield 0.94 g (93%). Anal.
calc. for C60H50P4N4Co, %: C, 71.36; I, 4.99; Co, 5.84.
Found, %: C, 71.23; I, 5.14; Co, 5.93. IR (nujol) m
(cmꢀ1): 1590 (m), 1238 (s), 1185 (m), 1140 (vs), 1117 (m),
1105 (w), 1026 (m), 997 (w), 950 (s), 918 (w), 800 (s), 748
(m), 742 (m), 720 (m), 695 (vs), 631(w), 616 (w), 539 (m),
546 (m), 530 (s), 522 (ww), 510 (m), 597 (w), 475 (w). Single
crystals of 2 suitable for X-ray crystallography were
obtained by slow cooling of the solution of 2 in the mixture
of the solvents THF, Et2O, PhMe (1:1:1). Dissolution of 2
in THF or toluene is accompanied with appearance of EPR
signal with gi = 2.256; temperature lowering (to 145 K)
results in hyperfine splitting of the signal (g1 = 2.009,
g2 = 2.313, g3 = 2.407). Electronic (vis) spectrum in PhMe
(k, nm): 503 (e = 80), 603 (e = 160), 686 (e = 70).
3.3.5. HNPh-PPh2@N-PPh2@O (7)
An ether solution of 6 was allowed to contact with moist
air overnight in closed vessel. Large poor soluble colorless
crystals were separated in quantitative yield. Anal. calc. for
C30H26P2N2O, %: C, 73.16; H, 5.32; P, 12.58. Found, %: C,
73.03; H, 5.40; P, 12.64. 31P{1H} NMR (CDCl3), d (ppm)
16.3, 11.3. 1H NMR d 6.12 (d, 1H, NH); 6.6–8.2 (m,
25H, Ph). IR (cmꢀ1): 3150 (m, NH), 1600 (m), 1295 (sh),
1255 (vs, P@N), 1230 (sh), 1165 (vs, P@O), 1116 (s), 1070
(w), 1024 (w), 1000 (w), 950 (s), 820 (w), 753 (s), 720 (s),
690 (s), 596 (w), 550 (vs), 512 (s).
3.3.3. Reaction of (Ph3P)2Ni-N(SiMe3)2 with 1
A mixture of toluene solutions of (Ph3P)2Ni-N(SiMe3)2
(0.58 g, 1.5 mmol, 10 mL) and 1 (1.43 g, 3.0 mmol,
20 mL) was maintained at 20 ꢁC for 1 h. The yellow mix-
ture turned dark-red. Toluene was changed for diethyl
ether. A dark-cherish crystalline precipitate of [PhNH-
N(PPh2)2]2Ni (3) was formed overnight. It was filtered,
washed with cold ether and dry in vacuum. Yield (0.65 g,
86%). Anal. calc. for C60H52P4N4Ni (3), %: C, 71.23, H,
5.18, Ni, 5.80. Found, %: C, 71.18; H, 5.10, Ni, 5.70. IR
(cmꢀ1): 1600 (m), 1310 (w), 1250 (w), 1160 (w), 1100 (m),
3.3.6. Co(NPh-PPh2@N-PPh2@S)2 (8)
A mixture of toluene solutions of 2 (0.50 g, 0,5 mmol,
10 mL) and elemental sulfur (0.047 g, 1.5 mmol, 5 mL)
was heated at 40 ꢁC for 30 min. Toluene was changed for
diethyl ether. A minor precipitate was filtered off. A blue
solution was concentrated and cooled with ice water.
Blue-violet crystals of 8 were separated by filtration. Yield
0.37 g (70%). Anal. calc. for C60H50P4N4S2Co, %: C, 67.10;
H, 4.69; Co, 5.49. Found, %: C, 66.80; H, 4.75; Co, 5.54.
Electronic (vis) spectrum (toluene) k, nm (e): 540 (120),
640 (400), 735 (160). IR (cmꢀ1); 1585 (m), 1435 (s), 1305
(w), 1280(w), 1235 (m), 1190 (vs), 1175 (s); 1120 (m),
1
880 (m), 750 (m), 700 (s), 530 (m), 510 (m), 470 (w). H
NMR (C6D6) d 6.05 (s, 2H, NH); 6.6–8.2 (m, 50H, Ph).
31P NMR (C6D6) d 113.9 ppm.

V.V. Sushev et al. / Journal of Organometallic Chemistry 691 (2006) 879–889
889
1110 (s), 1068 (w), 1028 (m), 1003 (m), 968 (vs), 806 (s), 747
(s), 725 (m), 692 (vs), 623 (m), 578 (vs), 531 (vs), 496 (m).
Crystals of 8 suitable for X-ray analysis were grown by
slow cooling of toluene solution.
C60H52P4N4SCo, %: C, 69.03; H, 5.02; Co, 5.65; S, 3.07.
Found, %: C, 69.53; H, 5.75; Co, 5.44; S, 3.16. Electronic
(vis) spectrum (THF) k, nm (e): 430 (350). IR (cmꢀ1):
3190 (w, NH), 1600 (m), 1280 (s), 1220 (m), 1115 (m),
1025 (w), 1000 (w), 915 (m), 750 (s), 720 (s), 690 (s), 600
(w), 520 (s). The product was formulated tentatively as
phosphino-sulfide [(HNPh-PPh2@N-PPh2)2CoS]x.
3.3.7. HNPh-PPh2@N-PPh2@S (9)
An ether solution of 8 was allowed to contact with moist
air overnight in closed vessel. Large poor soluble colorless
crystals were separated in quantitative yield. Anal. calc. for
C30H26P2N2S, %: C, 70.85; H, 5.15; S, 6.30. Found, %: C,
Acknowledgments
1
70.78; H, 5.15; S, 6.30. H NMR d 5.90 (d, 1H, NH); 6.5–
We are grateful to the Russian Foundation for Basic Re-
search (Grants 03-03-32051, 04-03-32830; scientific schools
1649.2003.3, 1652.2003.3) for financial support of this
work.
8.3 (m, 25H, Ph). 31P{1H} NMR (CDCl3), d (ppm) 44.2 (s),
17.2 (s). IR (cmꢀ1): 3208 (w, N-H), 1597 (s), 1498 (m), 1437
(m), 1400 (w), 1296 (w), 1253 (vs), 1226 (s), 1175 (m), 1120
(m), 1104 (m), 1026 (m), 1000 (w), 941 (s), 893 (w), 812 (m),
753 (s), 708 (m), 692 (vs), 602 (vs, P@S), 527 (s), 511(w),
500 (m).
References
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3.3.8. Interaction of 2 with CO
An excess of CO was allowed to react with solution of 2
in toluene at ambient temperature and pressure. Approxi-
mately 1 mol of CO was absorbed per mole of 2. The green
color of the solution turned greenish-brown. The electronic
spectrum showed fast disappearance of absorption bands
of the initial complex (k, nm: 503, 603, 686) while new
broad absorption at 735 nm arose. IR spectrum revealed
strong band at 1975 cmꢀ1 (a special experiment in CHCl3),
indicating formation of carbonyl cobalt complex. EPR
spectrum of the reaction mixture showed appearance of
novel doublet Ap = 140 G and additional hyperfine cou-
pling A = 27 G (gi = 2.088). Solvent removal gave starting
compound
spectroscopy.
2
according EPR, IR and electronic
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3.3.9. Interaction of 2 with diphenyldiazomethane
A solution of 2 (0.50 g, 0.5 mmol) and diphenyldiazome-
thane (0.194 g, 1,0 mmol) in 30 mL of toluene was irradi-
ated with UV lamp of low pressure for 2 h. The solution
was concentrated to ꢁ5 mL. Keeping the mixture overnight
at 10 ꢁC affords large blue-violet crystals of 12. Yield 0.28 g
(74%). Anal. calc. for C88H72P4N8O2Co2, %: C, 69.75; H,
4.79; Co, 7.78. Found, %: C, 69.52; H, 4.85; Co, 8.07. IR
(nujol) (cmꢀ1): 3680 (m, sharp, OH), 1590 (m), 1265 (w),
1205 (s), 1115 (m), 1035 (m), 1020 (m), 975 (w), 890 (m),
800 (m), 765 (w), 745 (m), 725 (m), 690 (s), 642 (m), 625
(m), 550 (m), 530 (m). Mother liquor shows two signals in
31P NMR spectrum, d (ppm): 20.8 (d, J = 4.7 Hz) and 4.3
(d, J = 4.7 Hz), been tentatively referred to a free ligand
(HNPh-PPh2@N-PPh2@N-N@CPh2)2, while the solution
of pure 12 has no 31P NMR spectrum.
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3.3.10. Interaction of 2 with H2S
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An excess of H2S (33.6 mL, 1.5 mmol) was allowed to
react with THF solution of 2 (0.50 g, 0.5 mmol) at ambient
temperature and pressure for 1 h. Deep brown solution was
evaporated to dryness in vacuum yields brown solid. No
EPR or 31P NMR spectra were registered. Anal. calc. for