Aminophosphines derived from N-phenylpiperazine and N-ethylpiperazine: Synthesis, oxidation reactions, and molybdenum complexes

Article abstract of DOI:10.1002/hc.20733

Functionalized aminophosphine of the type Ph₂PNR₂ (1,2) have been synthesized by treating Ph₂PCl with N-phenylpiperazine or N-ethylpiperazine. Oxidation of these ligands with aqueous hydrogen peroxide, elemental sulfur or

Full text of DOI:10.1002/hc.20733

Heteroatom Chemistry
Volume 22, Number 6, 2011
Aminophosphines Derived from
N-Phenylpiperazine and N-Ethylpiperazine:
Synthesis, Oxidation Reactions, and
Molybdenum Complexes
1
1
2
¨
¨
Ozlem Sarıo¨z, Sena Oznergiz, Hanife Sarac¸og˘lu,
and Orhan Bu¨yu¨kgu¨ngo¨r3
1Department of Chemistry, Faculty of Science and Arts, Nig˘de University, Nig˘de, Turkey
2Department of Middle Education, Educational Faculty, Ondokuz Mayıs University,
55139 Kurupelit, Samsun, Turkey
3Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayıs University,
55139 Kurupelit, Samsun, Turkey
Received 3 February 2011; revised 6 April 2011
It is not surprising that there continues to be a con-
ABSTRACT: Functionalized aminophosphine of the
siderable interest in the synthesis of new phosphines
type Ph2PNR2 (1,2) have been synthesized by treating
that have specific and well-characterized steric, elec-
Ph2PCl with N-phenylpiperazine or N-ethylpiperazine.
tronic, and solubility properties [3]. Aminophos-
Oxidation of these ligands with aqueous hydrogen per-
phines have been relatively neglected as ligands, de-
oxide, elemental sulfur or selenium afforded the corre-
spite a number of potentially attractive features. The
sponding phosphine oxides 3,4, sulfides 5,6, and se-
mild conditions required for the formation of P N
lenides 7,8 in good yields. The molybdenum complexes
bond allow facile incorporation of additional func-
of the aminophosphines have been obtained. All new
tionalities, and problems caused by the sensitivity
compounds were fully characterized by IR, NMR, and
of this bond to hydrolysis are often eliminated upon
microanalysis, and the molecular structures of two
coordination [4]. Interest in phosphines with P N
representative compounds were determined by single-
bonds arises from the different electronic properties
ꢀ
C
crystal X-ray crystallography. 2011 Wiley Periodicals,
transferred by the nitrogen center to the phospho-
rus center(s) [5]. Potentially, this ligand family is ex-
tremely attractive, because preparative routes enable
Inc. Heteroatom Chem 22:679–686, 2011; View this article
online at wileyonlinelibrary.com. DOI 10.1002/hc.20733
access to various structural modifications via simple
P N bond formation [6]. Aminophosphines possess-
INTRODUCTION
ing P N bonds have attracted considerable interest
because of their versatile coordination chemistry.
Although they posses two potential donor atoms,
their coordination compounds involve almost ex-
clusively the metal–phosphorus bond [7]. Many
aminophosphine ligands and their complexes have
been investigated in a number of catalytic processes
[6,8–11]. Some aminophosphines and derivatives
Phosphine ligands have many important applica-
tions in organometallic chemistry and catalysis [1,2].
¨
Correspondence to: Ozlem Sarıo¨z; e-mail: ozsarioz4@yahoo
.com.
c
ꢀ
2011 Wiley Periodicals, Inc.
679

680 Sarıo¨z et al.
E
Et3N
H2O2/S8/Se
Ph2PCl
+
H
N
N R
Ph2P
N
N
R
Ph2P
N
N R
Et3N.HCl
1–2
3–8
1: R= C6H5
2: R= C2H5
3: E=O, R= C6H5, 4: E= O, R= C2H5
5: E=S, R= C6H5, 6: E= S, R= C2H5
7: E=Se, R= C6H5, 8: E= Se, R= C2H5
FIGURE 1 Synthesis of aminophosphine ligands (1,2) and their oxidation reactions.
have also found application as anticancer drugs, her-
bicides, and antimicrobial agents, as well as neu-
roactive agents [8].
emental sulfur or selenium to give the correspond-
ing oxides (3,4), sulfides (5,6), and selenides (7,8),
respectively. The synthesis of aminophosphine lig-
ands (1,2) and their oxidation reactions are shown
in Fig. 1.
Herein, we describe the synthesis of new
aminophosphine ligands and the corresponding
aminophosphine chalcogenides of the general for-
mula Ph2P(E)NR2 and their molybdenum com-
plexes. The compounds were fully characterized by
IR, 1H NMR, 31P NMR spectroscopic techniques and
by elemental analysis. The molecular structures of 5
and 7 have been confirmed by X-ray studies.
The structure of the compounds (1,2) was con-
firmed by spectroscopic analysis. The spectroscopic
data for synthesized compounds is shown in Table 1.
1
The 31P-{ H} NMR spectra of the aminophosphines
show singlets at 35.2 ppm for 1 and 32.8 ppm for 2.
The absence of a signal at 81.5 ppm indicates that
no unreacted PPh2Cl remained [14]. The 31P NMR
spectra and 1H NMR spectra are consistent with the
proposed structure. In the IR spectra of the ligands,
the υ(PN) vibration is tentatively assigned to a very
strong absorption at 915 cm−1 for 1 and 925 cm−1
for 2, respectively [15,16]. The υ(PPh) bands are ob-
served in 1435 cm−1 for 1 and 1434 cm−1 for 2, re-
spectively [17].
RESULTS AND DISCUSSION
Earlier works had shown that primary and
secondary amines react with chlorophosphines
in the presence of a tertiary amine base to
form aminophosphines [12,13]. The reactions
of N-ethylpiperazine or N-phenylpiperazine with
diphenylchlorophosphine afford the corresponding
derivatives aminophospine Ph2PNC4H8NC6H5 (1)
and Ph2PNC4H8NC2H5 (2) in good yield. Both the N-
ethylpiperazine and N-phenylpiperazine derivatives
(1,2) react with aqueous hydrogen peroxide or el-
Oxidation of 1–3 aqueous hydrogen peroxide or
elemental sulfur or selenium gave the correspond-
ing oxides (3,4), sulfides (5,6), and selenides (7,8),
respectively. Oxidation of 1 and 2 using aqueous
H2O2 was very rapid even at ambient temperature.
TABLE 1 Spectroscopic Data of Synthesized Compounds
υ
Compound
δP
ꢀδ
PN
PPh
P O
P S
P Se
PPh2NC4H8NC6H5 (1)
35.2
32.8
18.7
18.7
66.8
66.4
68.0
67.6
94.1
93.4
107.1
915
925
932
929
910
938
908
938
951
953
956
1435
1434
1438
1438
1436
1439
1436
1439
1440
1439
1433
PPh2NC4H8NC2H5 (2)
Ph2P(O)NC4H8NC6H5 (3)
1176
1123
Ph2P(O)NC4H8NC2H5 (4)
Ph2P(S)NC4H8NC6H5 (5)
641
639
Ph2P(S)NC4H8NC2H5 (6)
Ph2P(Se)NC4H8NC6H5 (7)
Ph2P(Se)NC4H8NC2H5 (8)
cis-[Mo(CO)4(PPh2NC4H8NC6H5)2] (9)
cis-[Mo(CO)4(PPh2NC4H8NC2H5)2] (10)
trans-[Mo(CO)4(PPh2NC4H8NC2H5)2] (11)
576
588
58.9
60.6
74.3
Heteroatom Chemistry DOI 10.1002/hc

Aminophosphines Derived from N-Phenylpiperazine and N-Ethylpiperazine 681
TABLE 2 Crystallographic Data of Compound 5
However, the reaction with elemental sulfur or se-
lenium had to be carried out at elevated tempera-
tures, as expected because elemental sulfur and se-
lenium are weaker oxidizing agents than hydrogen
peroxide, especially toward phosphorus atoms with
bulky phenyl groups. As is typical of P(V) E com-
pounds, 31P chemical shifts of compounds 3–8 oc-
curred in the δ 18.7–68.0 ppm range, and the chemi-
cal shift region is quite consistent with the literature
for analogous derivatives [18–22]. As indicated in the
literature, coupling constants of 1 JPSe 765.6–773.8 Hz
Empirical Formula
C22 H23 N2 P1 S1
Mr
T (K)
378.45
296
˚
Radiation, λ (A)
0.71073
Orthorhombic
Pbca
Crystal system
Space group
Unit cell dimensions
˚
a (A)
11.3487(3)
19.6715(8)
18.3871(5)
˚
b (A)
˚
c (A)
1
are often seen for E Se [19]. The H NMR spectra
3
˚
V (A )
4104.8(2)
are consistent with the proposed structure. In the
IR spectra of 3–8, the υ(PN) vibration is observed
at 932 (3), 929 (4), 910 (5), 938 (6), 908 (7), and
938 cm−1 (8) [17]. The υ(PPh) bands are observed in
region of 1436–1439 cm−1. The IR spectra of 3 and
4 show υP O vibration at 1176 for 3 and 1123 cm−1
for 4, respectively [20]. In the IR spectra of the com-
pounds, while the υP O vibrations are observed in a
very narrow range, the υP N vibrations are observed
in a relatively wide range, suggesting that P(III) N
bonds are quite sensitive to the substituents attached
to them. The structures of the oxidized derivatives
(3 and 4), sulfides (5 and 6), and selenides (7 and 8)
were further confirmed by using microanalysis and
are found to be in good agreement with the theoret-
ical values.
Z
9
Dc (g/cm3)
1.378
0.274
1800
M (mm−1
F(000)
)
Crystal size (mm)
0.770 × 0.677 × 0.520
θ range (◦)
2.1/26.8
Index range (h, k, l)
Reflections collected
Independent reflections (Rint
Observed reflections [I > 2σ(I )]
Tmin, Tmax
−12/14, −24/24, −23/23
26657
)
4354 (0.033)
3441
0.8623, 0.8964
4354/235
1.07
0.038
0.109
0.35 and −0.36
Data/parameters
Goodness-of-fit on F2
Final R indices [I > 2σ(I )]
wR indices [I > 2σ(I )]
Largest difference peak and
−3
˚
hole (e. A
)
Compound 5 consists of phenyl and piperazine
rings linked through a phosphorus atom (Fig. 2).
Crystallographic data and selected bond lengths and
angles of compound 5 are given in Tables 2 and 3,
respectively. The steric interaction between the sub-
stituent groups on the piperazine ring means that
this ring deviates significantly from planarity. The
piperazine ring is in a chair conformation. The P S
˚
bond length is 1.9468(6) A. The phosphorus centers
are in typical tetrahedral environment. In this com-
pound (5), atom H14A of the piperazine ring acts as
a donor, resulting in the formation of C H· · · π hy-
drogen bonds, which are linked by the benzene ring
(C1–C6). There is also an intramolecular interaction
between the H atom of the phenyl and the sulfur
atom.
The molecular structure and crystallographic
data of compound 7 are shown in Fig. 3 [23] and
listed in Table 4. Their selected bond lengths and an-
gles are presented in Table 5. All of the benzene rings
TABLE 3 Selected Bond Lengths and Bond Angles of Com-
pound 5
˚
Bond Lengths (A)
P1–N1
P1–C1
P1–C7
P1–S1
N1–C16
1.6806(14)
N1–C13
N2–C14
N2–C15
N2–C17
1.4740(19)
1.4677(19)
1.452(2)
1.8192(16)
1.8145(16)
1.9468(6)
1.4694(19)
1.408(2)
Bond Angles (◦)
C1–P1–S1
S1–P1–C7
112.85(6)
113.06(6)
N1–P1–C7
N1–P1–C1
102.19(7)
103.25(7)
FIGURE 2 An ORTEP-3 [23] drawing of the molecule 5, with
the atom-numbering scheme.
Heteroatom Chemistry DOI 10.1002/hc

682 Sarıo¨z et al.
TABLE 4 Crystallographic Data of Compound 7
Empirical Formula
Mr
T (K)
C22 H23 N2 P1 Se1
425.35
296
˚
Radiation, λ (A)
0.71073
Orthorhombic
Pbca
Crystal system
Space group
Unit cell dimensions
˚
a (A)
11.3974(2)
19.6457(5)
18.4261(4)
˚
b (A)
˚
c (A)
3
˚
V (A )
4125.8(2)
Z
9
Dc (g/cm3)
1.541
2.144
μ (mm−1
)
F(000)
1962
Crystal size (mm)
0.650 × 0.440 × 0.290
θ range (◦)
2.1/26.8
Index range (h, k, l)
Reflections collected
Independent reflections (Rint
Observed reflections[I > 2σ(I )]
Tmin, Tmax
−14/13, −24/24, −23/23
33884
)
4381 (0.050)
3720
0.3282, 0.5786
4381/235
1.07
0.043
0.106
0.77 and −0.76
FIGURE 3 An ORTEP-3 [23] drawing of the molecule 7, with
the atom-numbering scheme.
Data/parameters
Goodness-of-fit on F2
Final R indices [I > 2σ(I)]
wR indices [I > 2σ(I )]
Largest difference peak and
ometry, the angles around the P atom ranging from
103.56(10) to 116.7(8)◦. Analysis of the crystal pack-
ing shows that the molecules of compound 7 are
linked by intermolecular C H· · · π interactions in-
volving the phenyl ring (C7–C12) and a H atom of
the piperazine ring. Two intramolecular hydrogen
bonds are also formed in compound 7.
The molybdenum carbonyl derivatives, cis-
[Mo(CO)4(L)2] (L = PPh2NC4H8NC6H5, 9; L =
PPh2NC4H8NC2H5, 10) were obtained by the dis-
placement of bipyridine from the [Mo(CO)4(bipy)].
The metal carbonyl derivatives are shown in Fig. 4.
The molybdenum carbonyl derivatives, cis-
[Mo(CO)4(L)2] (9,10), were characterized by IR,
−3
˚
hole (e. A
)
are each planar. In the phenyl ring, atom C17 devi-
˚
ates by 0.0090(19) A from the mean plane through
the C17–C22 ring. The piperazine ring exhibits a
chair conformation. The P N bond length of 1.683
˚
A is shorter than the normally accepted value for a
˚
single bond (1.77 A) [24]. The aromatic rings in the
molecule, as expected, have the usual bond lengths
and angles. The phosphorus center, coordinated by
endocylic N and C atoms from the piperazine and
aromatic moieties and Se atom (C N P C), adopts
an antiperiplanar conformation. This PC2NSe coor-
dination forms a slightly distorted tetrahedral ge-
CO
Mo
CO
L
Mo
L
OC
OC
OC
OC
L
L
CO
CO
TABLE 5 Selected Bond Lengths and Bond Angles of Com-
pound 7
˚
Bond Lengths (A)
P1–N1
P1–C1
P1–C7
P1–Se1
N1–C16
1.683(2)
N1–C13
N2–C14
N2–C15
N2–C17
1.480(3)
1.462(3)
1.449(3)
1.409(3)
1.811(3)
1.815(3)
2.1053(7)
1.469(3)
11
9–10
11: L=Ph2PNC4H8NC2H5
9:
L=Ph2PNC4H8NC2H5
L=Ph2PNC4H8NC6H5
10:
Bond Angles (◦)
C1–P1–C7
C7–P1–N1
107.01(11)
103.56(10)
N1–P1–Se1
Se1–P1–C1
116.97(8)
113.20(9)
FIGURE 4 Proposed structures of [Mo(CO)4(L)2] com-
plexes.
Heteroatom Chemistry DOI 10.1002/hc

Aminophosphines Derived from N-Phenylpiperazine and N-Ethylpiperazine 683
NMR, and elemental analysis. Ligands bearing both
NMR spectra, 11 exhibits a singlet, which shows the
expected low-field shift relative to the uncoordinated
ligand [11: 107.1 ppm (ꢀδ = 74.3 ppm)] [15,16].
The phosphorus chemical shift for the complex
indicates the P–Mo interaction. In the IR spectrum
of the complex 11, the υ(PN) vibration is tentatively
assigned to a very strong absorption at 956 cm−1,
which is shifted to a higher wavenumber for 11
(ꢀυ = 31 cm−1) compared with their free ligands
[15,16]. The υ(PPh) band is observed in 1433 cm−1.
Further confirmation for the trans geometry of com-
plex 11 comes from IR spectra, which show single
absorption for υCO at 1888 cm−1, characteristic of
complexes containing trans-Mo(CO)4 moieties [29].
amine and tertiary phosphine donors can behave as a
monodentate ligand (via P or N) or a bidentate ligand
(via P and N). The P N bond in aminophosphines
is essentially a single bond, so the lone pairs on ni-
trogen and phosphorus are available for donor bond-
ing toward metal atoms. However, no examples have
been synthesized where both P and N have acted as
donor atoms. It is only P that acts as the donor atom.
The phosphorus chemical shift for complexes indi-
cates the P–M interaction due to the low coordina-
1
tion shift value of complexes (ꢀδ). In the 31P-{ H}
NMR spectra, 9 and 10 exhibit singlets that show
the expected low-field shifts relative to the uncoordi-
nated ligands [9: 94.1 ppm (ꢀδ = 58.9 ppm) and 10:
1
93.4 ppm (ꢀδ = 60.6 ppm)] [15]. The 31P-{ H} NMR
EXPERIMENTAL
chemical shifts of 9 and 10 are also within the ex-
pected range for structurally similar complexes [16].
The phosphorus chemical shifts for the complexes
indicate the P–Mo interaction. In the IR spectra of
the metal carbonyl complexes, the υ(PN) vibration
is tentatively assigned to a very strong absorption at
951 cm−1 for 9 and 953 cm−1 for 10, respectively,
which is shifted to higher wavenumbers for 9 (ꢀυ =
36 cm−1) and 10 (ꢀυ = 28 cm−1) compared with their
free ligands [15,16]. The υ(PPh) bands are observed
in 1440 cm−1 for 9 and 1439 cm−1 for 10, respectively.
The infrared spectra of the complexes [Mo(CO)4L2]
exhibit four intense υ(CO) absorptions, in the car-
bonyl region (1772–2011 cm−1), characteristic of the
presence of cis-[Mo(CO)4] with C2v symmetry [6,25–
28]. The generation of [Mo(CO)4L] complexes may
be used as a rapid “spot test” for the donor properties
of new ligands. This attribute has been recognized
for many years, and an extensive literature exists for
these complexes, allowing ready comparison with a
variety of other phosphorus(III) ligands. The value
υCO has been used to evaluate the ligand electronic
properties [1]. The position of υCO for the molyb-
denum complexes (9 and 10) is shown in Table 6. It
was found that in the molybdenum complex, 9 and
10 have similar υCO stretching frequency, indicating
that 1 and 2 have electronic properties.
Reactions were routinely carried out using Schlenk-
line techniques under pure dry nitrogen gas.
Solvents were dried and distilled prior to use.
[Mo(CO)4(bipy)] was prepared according to the lit-
erature procedures [30]. All other chemicals were
reagent grade, available commercially, and used
without further purification. Melting points were de-
termined on a Electrothermal A 9100 and are un-
1
corrected. 31P-{ H} and 1H NMR spectra were taken
on Bruker UltraShield-400 spectrophotometer. In-
frared spectra were recorded on a Perkin Emler FT-
IR system spectrum BX as KBr pellets. Elemental
analysis was performed in a CHNS-932 (LECO).
Preparation of PPh2NC4 H8NC6 H5 (1)
Triethylamine (2.3 mL, 16.59 mmol) and Ph2PCl
(3.0 mL, 16.33 mmol) were sequentially added with
stirring to a solution of N-phenylpiperazine (2.5 mL,
16.37 mmol) in THF (20 mL). The reaction mix-
ture was stirred for 6 h and then filtered to remove
Et3N.HCl. The resulting solution was evaporated un-
der reduced pressure, and the product was extracted
with diethyl ether at −78◦C. The solvent was removed
under vacuum to give a white solid of the crude
product, which was crystallized from CH2Cl2/diethyl
ether mixture (2:1) at 0◦C. Yield 4.64 g (82%). mp:
The reaction of
2
with Mo(CO)6 un-
1
153–154◦C. H NMR (CDCl3, δ, ppm): 7.21–7.85 (m,
der refluxing conditions produces the trans-
1
[Mo(CO)4(PPh2NC4H8NC2H5)2] (11). In the 31P-{ H}
Ph, 15H), 3.30 (t, N-CH2, 4H), 3.16 (t, N-CH2, 4H).
TABLE 6 Comparison of υCO of [M(CO)4L2]
Complexes
υCO (cm−1
)
cis-[Mo(CO)4(PPh2NC4H8NC6H5)2] (9)
cis-[Mo(CO)4(PPh2NC4H8NC2H5)2] (10)
trans-[Mo(CO)4(PPh2NC4H8NC2H5)2] (11)
2010, 1897, 1802, 1775
2011, 1893, 1811, 1772
1888
Heteroatom Chemistry DOI 10.1002/hc

684 Sarıo¨z et al.
(CDCl3, δ, ppm): 35.2 (s). Selected IR (KBr, cm−1):
915 (PN), 1435 (PPh). Elemental analysis: C22H23PN2
(346.40 g mol−1) Found (required): C, 76.15 (76.28);
H, 6.50 (6.69); N, 7.94 (8.09).
66.8 (s). Selected IR (KBr, cm−1): 910 (PN), 641 (PS),
1436 (PPh). Elemental analysis: C26H24PNS (378.47 g
mol−1) Found (required): C, 69.68 (69.82); H, 5.99
(6.12); N, 7.23 (7.40); S, 8.28 (8.47).
Preparation of PPh2NC4 H8NC2 H5 (2)
Preparation of Ph2P(S)NC4 H8NC2 H5 (6)
A similar procedure to that described in 1 was used.
Yield 4.38 g (75%). mp: 166–167◦C. 1H NMR (CDCl3,
δ, ppm): 7.01–7.94 (m, Ph, 10H), 2.78 (t, N-CH2, 4H),
2.45 (t, N-CH2, 4H), 2.35 (q, N-CH2, 2H), 0.95 (t,
A similar procedure to that described in 5 was used.
1
Yield 0.3 g (38%). mp: 126–127◦C. H NMR (CDCl3,
δ, ppm): 7.49–8.01 (m, Ph, 10H), 2.68 (t, N-CH2, 4H),
2.43 (t, N-CH2, 4H), 2.31 (q, N-CH2, 2H), 0.95 (t,
1
1
CH3, 3H). 31P-{ H} NMR (CDCl3, δ, ppm): 32.8 (s).
CH3, 3H). 31P-{ H} NMR (CDCl3, δ, ppm): 66.4 (s).
Selected IR (KBr, cm−1): 925 (PN), 1434 (PPh). Ele-
mental analysis: C18H23PN2 (298.36 g mol−1) Found
(required): C, 72.22 (72.46); H, 7.68 (7.77); N, 9.27
(9.39).
Selected IR (KBr, cm−1): 938 (PN), 639 (PS), 1439
(PPh). Elemental analysis: C18H23PN2S (330.43 g
mol−1) Found (required): C, 65.27 (65.43); H, 6.82
(7.02); N, 8.35 (8.48); S, 9.56 (9.70).
Preparation of Ph2P(O)NC4 H8NC6 H5 (3)
Preparation of Ph2P(Se)NC4 H8NC6 H5 (7)
A THF solution (10 mL) of 1 (0.65 g, 1.88 mmol)
and aqueous H2O2 (30% w/w, 0.2 mL) was stirred
for 2 h at room temperature. The reaction mixture
was concentrated to ca. 1–2 mL in vacuo, and di-
ethylether (20 mL) was added. The precipitate was
filtered and dried in air to yield 3. Yield 0.30 g (44%).
mp: 124–125◦C. 1H NMR (CDCl3, δ, ppm): 7.20–8.00
(m, Ph, 15H), 3.20 (t, N-CH2, 4H), 2.75 (t, N-CH2,
Ligand 1 (0.77 g, 2.22 mmol) and gray Se (0.175 g,
2.22 mmol) were refluxed in toluene (20 mL) for 3 h.
The reaction mixture was concentrated to ca. 1–2 mL
in vacuo, and diethylether (20 mL) was added. The
precipitate was filtered and dried in air to yield 7.
Yield 0.59 g (63%). mp: 158–159◦C. 1H NMR (CDCl3,
δ, ppm): 6.69–8.10 (m, Ph, 15H), 3.26 (t, N-CH2, 4H),
1
2.77 (t, N-CH2, 4H). 31P-{ H} NMR (CDCl3, δ, ppm):
4H). 31P-{ H} NMR (CDCl3, δ, ppm): 18.7(s). Se-
68.0 (s, JPSe = 773.8 Hz). Selected IR (KBr, cm−1):
908 (PN), 576 (PSe), 1436 (PPh). Elemental analysis:
C22H23PN2Se (425.36 g mol−1) Found (required): C,
61.91 (62.12); H, 5.27 (5.45); N, 6.36 (6.59).
1
lected IR (KBr, cm−1): 932 (PN), 1438 (PPh), 1176
(P O). Elemental analysis: C22H23PN2O (362.40 g
mol−1) Found (required): C, 72.59 (72.91); H, 6.25
(6.40); N, 7.56 (7.73).
Preparation of Ph2P(Se)NC4 H8NC2 H5 (8)
Preparation of Ph2P(O)NC4 H8NC2 H5 (4)
A similar procedure to that described in 7 was used.
Yield 0.40 g (70%). mp: 115–116◦C. 1H NMR (CDCl3,
δ, ppm): 7.50–8.05 (m, Ph, 10H), 2.63 (t, N-CH2, 4H),
A similar procedure to that described in 3 was used.
Yield 0.33 g (69.5%). mp: 86–88◦C. 1H NMR (CDCl3,
δ, ppm): 7.37–7.72 (m, Ph, 10H), 3.10 (t, N-CH2, 4H),
2.90 (t, N-CH2, 4H), 2.31 (q, N-CH2, 2H), 0.95 (t,
2.49 (t, N-CH2, 4H), 2.34 (q, N-CH2, 2H), 0.97 (t, CH3,
1
3H). 31P-{ H} NMR (CDCl3, δ, ppm): 67.6 (s, JPSe
=
CH3, 3H). 31P-{ H} NMR (CDCl3, δ, ppm): 18.7 (s).
765.6 Hz). Selected IR (KBr, cm−1): 938 (PN), 588
(PSe), 1439 (PPh). Elemental analysis: C18H23PN2Se
(377.32 g mol−1) Found (required): C, 57.18 (57.30);
H, 5.99 (6.14); N, 7.26 (7.42).
1
Selected IR (KBr, cm−1): 929 (PN), 1438 (PPh), 1123
(P O). Elemental analysis: C18H23PN2O (314.36 g
mol−1) Found (required): C, 68.51 (68.77); H, 7.25
(7.37); N, 8.76 (8.91).
Preparation of cis-[Mo(CO)4(PPh2NC4 H8NC6
H5)2] (9)
Preparation of Ph2P(S)NC4 H8NC6 H5 (5)
Ligand 1 (0.66 g, 1.9 mmol) and S8 (0.06 g, 1.9 mmol)
were refluxed in toluene (20 mL) for 6 h. The reaction
mixture was concentrated to ca. 1–2 mL in vacuo,
and diethylether (20 mL) was added. The precipi-
tate was filtered and dried in air to yield 5. Yield
Ligand 1 (0.61 g, 1.76 mmol) and [Mo(CO)4(bipy)]
(0.32 g, 0.88 mmol) were refluxed in 20 mL CH2Cl2
for 4.5 h. The solution was concentrated in vacuo,
and the purple product was precipitated with di-
ethylether (30 mL). The purple residue was washed
with toluene (3 × 5 mL). Yield: 0.69 g (87%). mp:
183–185◦C (decomp). 1H NMR (CDCl3, δ, ppm):
6.80–8.01 (m, Ph, 30H), 3.14 (t, N-CH2, 8H), 3.05
1
0.41 g (57%). mp: 128–129◦C. H NMR (CDCl3, δ,
ppm): 6.77–8.05 (m, Ph, 15H), 3.22 (t, N-CH2, 4H),
1
2.84 (t, N-CH2, 4H). 31P-{ H} NMR (CDCl3, δ, ppm):
Heteroatom Chemistry DOI 10.1002/hc

Aminophosphines Derived from N-Phenylpiperazine and N-Ethylpiperazine 685
1
(t, N-CH2, 8H). 31P-{ H} NMR (CDCl3, δ, ppm): 94.1.
Selected IR (KBr, cm−1): 951 (PN), 1440 (PPh),
2010, 1897, 1802 and 1775 (CO). Elemental analysis:
C48H46P2N4O4Mo (900.79 g mol−1) Found (required):
C, 63.83 (64.00); H, 4.88 (5.15); N, 5.98 (6.22).
for 5 and 7. Copies of this information may be
obtained free of charge from the Director, CCDC,
12 Union Road, Cambridge CB2 1EZ, UK (Fax:
+44-1223-336033; e-mail: deposit@ccdc.cam.ac.uk
or http://www.ccdc.cam.ac.uk).
Preparation of cis-[Mo(CO)4(PPh2NC4 H8NC2
H5)2] (10)
ACKNOWLEDGMENTS
Partial support of this work by TUBITAK (project
number 110T572) and Nigde University (project
number FEB 2008/20) is gratefully acknowledged.
A similar procedure to that described in 9 was used.
1
Yield: 0.35 g (49%). mp: 180–181◦C (decomp). H
NMR (CDCl3, δ, ppm): 7.06–8.65 (m. Ph, 20H), 2.87
(t, N-CH2, 8H), 2.63 (t, N-CH2, 8H), 2.31(q, N-CH2,
4H), 0.96 (t, CH2CH3, 6H). 31P-{ H} NMR (CDCl3, δ,
1
REFERENCES
ppm): 93.4. Selected IR (KBr, cm−1): 953 (PN), 1439
(PPh), 2011, 1893, 1811, and 1772 (CO). Elemental
analysis: C40H46P2N4O4Mo (804.70 g mol−1) Found
(required): C, 59.53 (59.70); H, 5.58 (5.76); N, 6.67
(6.96).
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Preparation of trans-[Mo(CO)4(PPh2NC4 H8NC2
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1
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CONCLUSIONS
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