Structural characterization and catalytic activities of copper complexes with pyridine-amine-phosphine-oxide ligand

Article abstract of DOI:10.1016/j.jorganchem.2004.09.054

A new tetradentate containing pyridine, amine and phosphine oxide donor systems (1) was synthesized by the condensation of o-diphenylphosphinoaniline with 2-pyridinecarbaldehyde. Reaction of 1 with equal molar amount of CuCl ₂ and Cu(ClO₄)₂ provided the formation of [CuCl₂(1)] (4) and [[Cu(1)(H₂O)](ClO₄) ₂] (5), respectively. The ligand 1 behaves as a tridentate in 4, while as a tetradentate in 5. Both complexes were characterized by EPR, UV-Vis spectroscopy and X-ray diffraction. Both copper(II) complexes are in a square-pyramidal geometry. Single crystal structure of the copper complex reveals that the copper center is surrounded by three nitrogen donors and two chloride for 4; three nitrogen donors, water and oxygen donor from the moiety of phosphine oxide for 5. Complexation of 1 with CuCl in dichloromethane resulted in the formation of the corresponding copper(I) species, which catalyzed the oxidation of benzylic alcohols under aerobic conditions.

Full text of DOI:10.1016/j.jorganchem.2004.09.054

Journal of Organometallic Chemistry 690 (2005) 415–421
www.elsevier.com/locate/jorganchem
Structural characterization and catalytic activities of
copper complexes with pyridine-amine-phosphine-oxide ligand
*
Weiwen Tsai, Yi-Hung Liu, Shie-Ming Peng, Shiuh-Tzung Liu
Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Rd., Taipei 106, Taiwan, ROC
Received 20 August 2004; accepted 22 September 2004
Abstract
A new tetradentate containing pyridine, amine and phosphine oxide donor systems (1) was synthesized by the condensation of
o-diphenylphosphinoaniline with 2-pyridinecarbaldehyde. Reaction of 1 with equal molar amount of CuCl2 and Cu(ClO4)2 provided
the formation of [CuCl2(1)] (4) and [[Cu(1)(H2O)](ClO4)2] (5), respectively. The ligand 1 behaves as a tridentate in 4, while as a tetra-
dentate in 5. Both complexes were characterized by EPR, UV–Vis spectroscopy and X-ray diffraction. Both copper(II) complexes
are in a square-pyramidal geometry. Single crystal structure of the copper complex reveals that the copper center is surrounded by
three nitrogen donors and two chloride for 4; three nitrogen donors, water and oxygen donor from the moiety of phosphine oxide
for 5. Complexation of 1 with CuCl in dichloromethane resulted in the formation of the corresponding copper(I) species, which
catalyzed the oxidation of benzylic alcohols under aerobic conditions.
ꢀ 2004 Elsevier B.V. All rights reserved.
Keywords: Phosphine-oxide; Amine; Catalysis; Copper; Oxidation
1. Introduction
as galactose oxidase [9]. In this context a great number
of copper(II) complexes containing chelating nitrogen
donors including pyridinyl, imidazoyl and polyamino
ligands in model studies were reported [1–8]. In such
pursuit, we synthesized a designed tetradentate 1 involv-
ing two pyridine nitrogens, one secondary amine group
as well as a phosphine-oxide moiety in its ligand set and
studied its coordination behavior toward copper ions.
There is a considerable interest in the design of mul-
tiple mixed donors, which can offer both hard and soft
donor environment in these ligands for their coordina-
tion behavior toward transition metal ions. It is believed
that the properly designed ligand systems would provide
new property and reactivity of the resulting metal com-
plexes [1]. Thus, developments of new copper complexes
for their potential as catalysts in oxidation of organic
substrates continue to be attractive [1–9]. Among vari-
ous coordination modes for copper(II), complexes with
five-coordinate adopting in a square-pyramidal geome-
try were found in natural occurring metalloproteins such
Ph
Ph
O
P
NH
N
*
Corresponding author. Tel.: +886 2 2366 0352; fax: +886 2 2363
N
6359.
E-mail address: stliu@ccms.ntu.edu.tw (S.-T. Liu).
1
0022-328X/$ - see front matter ꢀ 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2004.09.054

416
W. Tsai et al. / Journal of Organometallic Chemistry 690 (2005) 415–421
2. Results and discussion
2.1. Preparation of ligands
The desired ligand was prepared through the reaction
of 2-diphenylphosphinoaniline with 2-pyrdinecarbalde-
hyde followed by the hydrogenation (Scheme 1, path
a). Without any acid catalyst, the condensation reaction
took place immediately in methanol at 50 ꢁC and quan-
titatively provided the formation of enamine product 2.
Upon the recrystallization, this compound appears to be
a clear, colorless single crystal. This reaction has also
been investigated by Doherty et al. (Scheme 1, path b)
[10]. In the presence of formic acid, the adduct 3 from
imine and aldehyde was obtained at ambient tempera-
ture in toluene. Presumably, the reaction at higher tem-
perature in the polar solvent readily facilitates the
dehydration to form 2. Metal catalyzed hydrogenation
of 2 in the presence of atmospheric hydrogen gave the
desired ligand 1.
Fig. 1. ORTEP plot of 2. Selected bond distances and angles: P(1)–
˚
C(1) 1.806(3) A; P(1)–O(1) 1.483(2) A; P(1)–C(13) 1.811(3) A; C(18)–
˚
˚
˚
˚
˚
N(1) 1.412(3) A; N(1)–C(19) 1.379(3) A; C(19)–C(20) 1.356(4) A;
C(18)–N(1)–C(19) 125.3(2)ꢁ; N(1)–C(19)–C(20) 122.8(3)ꢁ; N(1)–C(19)–
C(20) 118.2(2)ꢁ.
moiety in the presence of the molecule. As for the hydro-
genated product 1 is easily characterized by both NMR
spectroscopy and elemental analysis.
Compound 2 was characterized by both spectro-
scopic and X-ray crystallographic methods. A shift at
30.7 ppm in the 31P NMR spectrum of 2 shows the exist-
ence of tertiary-phosphine oxide in the molecule. In
addition to the aromatic protons, the appearance of
2.2. Copper complexes
Under refluxing conditions, reaction of CuCl2 with
equimolar amount of 1 in absolute ethanol for 3 h pro-
vided the green complex [CuCl2(1)] (4), whereas com-
plexation of 1 with Cu(ClO4)2 Æ 6H2O gave the ionic
complex [Cu(H2O)(1)](ClO4)2 (5) in green solids. By
the recrystallization, X-ray suitable crystals for both
complexes can be accomplished. ORTEP plots of both
complexes 4 and 5 are deposited in Figs. 2 and 3, respec-
tively. The copper(II) center in both complexes has the
distorted square-pyramidal geometry with one nitrogen
donor [N(2)] from the ligand seated in the apical posi-
tion. The basal plane in complex 4 was formed by two
chloride donors and two nitrogen atoms [N(1) and
N(3)] from the ligand. The formation of a stable five-
member chelate ring by the secondary amine N(3) and
pyridine nitrogen N(1) is presumably an explanation
for these two donors in the equatorial direction. The
1
one singlet absorption at 6.23 ppm in H NMR, which
is in the typical range for olefinic protons, suggests the
formation of carbon–carbon double bond functionality.
Although the spectral data of 2 are consistent with the
proposed structure, the confirmation comes from the
single crystal analysis. Fig. 1 shows its ORTEP plot with
30% ellipsoid. All bond lengths and angles are in agree-
ment with the reported values. The C(19)–C(20) bond
˚
length of 1.356(4) A is a typical distance for C@C,
˚
whereas the distance of 1.379(3) A for C(19)–N(1)
clearly illustrates the single bond nature between two
atoms. These observations also confirm the enamine
Ph
Ph
O
P
path a
NH
N
H2
Ph
50 oC
Ph
1
P
CH3OH
Pd/C
N
Ph
2
NH2
Ph
path b
rt
+
P
O
N
Toluene
HCOOH
O
NH
N
N
OH
3
Scheme 1. Ligand preparation.
Fig. 2. Molecular structure of copper complex 4.

W. Tsai et al. / Journal of Organometallic Chemistry 690 (2005) 415–421
417
Five-coordinate Cu(II) complexes are quite common
and their stereochemistry are adopted ranging between
square-pyramidal (SP) and trigonal-bipyramidal
(TBP). In complexes 4 and 5, the preference in SP is pre-
sumably due to the geometrical arrangement of donors
in 1. This type of geometry was also observed for the re-
lated species [CuCl2(N3)] [12]. The coordination of phos-
phine-oxide toward metal center is readily through the
assistance of the chelate effect of this multidentate 1.
All the distances of Cu–N in 4 appear to be longer than
those in 5, which might be the results of the steric relief
of ligand interaction. The free phosphine-oxide in 4 may
cause the steric strain between substituents on phospho-
rus and chloride ligands, which causes the elongation of
the distances between metal center and nitrogen donors.
In addition to crystallography, both EPR spectro-
scopic data and electronic absorption are in agreement
with the structure. The X-band EPR spectra of 4 and
5 in methanol glass (80 K) were determined and their
data were collected in Table 3. It appears that both com-
plexes with the parameters gi > g^ are typical mono-
meric square-pyramidal copper(II) complexes with
Fig. 3. ORTEP drawing of the cationic part of 5.
coordination mode of nitrogen donors in complex 5 is
similar to those in 4, but the oxygen atom [O(1)] of
phosphine-oxide moiety of the ligand is bounded to me-
tal center. Thus donor atoms of N(1), N(3), and O(1) as
well as a water molecule formed the basal plane in 5.
The bond distances and bond angles of basal plane of
both complexes are summarized in the Fig. 4. A signifi-
cant difference in the structure of 4 compared to that of
5 is that all Cu–N lengths in 4 are longer those in 5 par-
À y2
dx2
ground state [11]. The spectra of 4 and 5 re-
˚
corded as mulls show a broad band centered at 540
and 567 nm, respectively, which are in agreement of
the d–d transitions for a square-pyramidal copper(II)
complex with pyridine donors [13]. Table 1 also includes
the electronic absorptions in methanol of both com-
plexes. The absorptions in UV region are assigned as
the transition from the ligand itself, whereas the kmax
around 370 nm is believed due to the LMCT band. In
addition, complex 4 in methanol exhibits a d–d band
around 740 nm with a shoulder to lower wave-numbers,
a characteristic profile for the copper(II) species in
square-pyramidal geometry. This outcome also indicates
that the complexes remain the same structural feature in
solution.
ticularly the apical one [Cu–N(2) = 2.334(3) A in 4;
˚
2.254(8) A in 5]. Also, bond lengths of Cu–N(1) are
somewhat shorter than those of Cu–N(3), which is
attributed to the different hybridization of nitrogen do-
nors; the N(1) is a pyridinyl nitrogen, whereas N(3) is
a secondary amine group. In both complexes, the dis-
tance of the apical nitrogen to copper center is longer
˚
by ca. 0.3 A than those of equatorial ones, indicating
a weak interaction in the apical orientation. All bond
distance and bond angles in both complexes lie within
normal ranges except N(2)–Cu–N(3) [80.8(1)ꢁ]. How-
ever, it is noticed that the angles Cl(1)–Cu–Cl(2) in 4
[96.36(4)ꢁ] much derived from the 90ꢁ as compared to
the smaller derivation of O(1)–Cu–O(2) [87.9(2)ꢁ].
For the copper(I) complex [CuCl(1)] (6) was prepared
by simple mixing the ligand 1 and CuCl in acetonitrile
under nitrogen atmosphere. The un-coordination of
phosphine oxide moiety toward metal center was sug-
gested by the observation of 31P NMR shift at 36.3
ppm, which was essentially similar to that for free lig-
N(2)
2.334(3)
N(2)
2.254(8)
)
)
6
(
1
(
7
5
5
5
9
.
.2
2
N(1)
N(3)
Cl(1)
O(2)
O(1)
1
.
N(1)
N(3)
Cu
Cu
1
1
)
7
(
0
and. The H NMR splitting pattern and chemical shifts
2
.
Cl(2)
9
)
3
2
2
1
(
5
(
4
8
4
0
.
2
5
)
(
7
0
.
2
1
)
for the complex were different from the ligand 1 itself,
indicating the coordination of nitrogen donors to the
copper center. Unfortunately, we were not able to ob-
tain the single crystal of this complex for the confirma-
tion of its detail coordination environments.
o
o
o
N(1)-Cu-N(3) 81.1(1)
N(1)-Cu-N(3) 81.8(3)
o
N(3)-Cu-Cl(2) 89.30(9)
N(3)-Cu-O(2) 93.7(3)
O(2)-Cu-O(1) 87.9(2)
o
o
o
Cl(2)-Cu-Cl(1) 96.36(4)
o
Cl(1)-Cu-N(1) 92.80(9)
N(3)-Cu-Cl(1) 173.80(9)
N(1)-Cu-Cl(2) 161.74(9)
O(2)-Cu-N(1) 94.3(3)
o
o
o
N(3)-Cu-O(2) 169.3(3)
N(1)-Cu-O(1) 166.3(3)
o
o
o
2.3. Catalytic oxidation of alcohols
N(2)-Cu-N(1) 91.6(1)
N(2)-Cu-N(1) 90.6(3)
N(2)-Cu-N(3) 88.6(3)
o
o
N(2)-Cu-N(3) 80.8(1)
o
o
o
N(2)-Cu-Cl(1) 100.36(9)
N(2)-Cu-Cl(2) 102.22(9)
N(2)-Cu-O(1) 102.2(2)
N(2)-Cu-O(2) 101.4(3)
In the catalytic oxidation, both complexes 4 and 5 did
not show much activity for the conversion of benzyl
alcohol into benzaldehyde. However, the copper(I) com-
plex can act as a catalyst for the oxidation of benzylic
o
˚
Fig. 4. Comparison of bond distances (A) and angles around the metal
centers between 4 and 5.

418
W. Tsai et al. / Journal of Organometallic Chemistry 690 (2005) 415–421
Table 1
EPR spectroscopic dataa and electronic absorptions of 1, 4 and 5b
b
gi
g^
Ai (G)
kmax
1
4
5
6
–
–
–
210(41.93)
211(21.68)
211(31.78)
207(54.3)
260(13.06)
261(15.01)
261(10.79)
260(14.7)
326(5.05)
321(1.91)
324(2.98)
325(4.99)
2.284
2.311
–
2.071
2.078
–
144
173
–
371(0.85)
369(2.13)
372(1.09)
421(0.62)
516(0.18)
432(0.18)
743(0.11)
700(0.07)
514(0.16)
a
In methanol glass (80 K).
In methanol, e is given in the parenthesis (·103
b
M
À1 cmÀ1), but 6 in acetonitrile.
alcohol into the corresponding carbonyl compound. In a
typical experiment for the reaction, a mixture of benzyl
alcohol, copper(I) chloride, ligand 1 and base in a
freshly distilled N-methylprolidinone (NMP) solution
was heated in a oil bath at 110 ꢁC in the presence of
air or oxygen gas for a specified time. The reaction prod-
uct was monitored by 1H NMR and the yield was based
on the integration. All results are summarized in
Table 2.
Complete conversion of benzyl alcohol into benzal-
dehyde was observed with the catalytic system of
Cu(I)/ligand 1 or complex 6 in the presence of dioxy-
gen at 110 ꢁC (entries 1–2). For other substrates, var-
ious kind of benzylic alcohols can be oxidized into the
corresponding carbonyl compound by Cu(I)/ligand 1
under oxygen atmosphere. Complete oxidation of
benzoin into benzil was accomplished within 2.5 h (en-
try 10, Table 2). Similarly, the yield of the oxidation
of diphenylmethanol to give benzophenone could be
reached up to 100% within 12 h. This catalytic system
also provided reasonable conversion with other sub-
strates except the steric bulky alcohol (entry 8, Table
2). It was noticed that this copper complex did not
have activity in the oxidation of diphenylmethane
and allylic alcohol (entries 12–13). However, the oxi-
dation of (E)-3-phenyl-2-propenol could be converted
into cinnamaldehyde presumably due to its
conjugation.
Table 2
Catalytic oxidation of alcoholsa
Entry
Substrates
Product
t (h)
Conversionc (%)
1
C6H5CH2OH
C6H5CH2OH
C6H5CHO
C6H5CHO
60
60
12
12
17
14
14
100
100
85
2b
3
3-(NO2)C6H4CH2OH
4-(MeO)C6H4CH2OH
2-IC6H4CH2OH
3-(NO2)C6H4CHO
4-(MeO)C6H4CHO
2-IC6H4CHO
4
59
72
5
6
2-Pyridinylmethanol
C6H5CH(CH3)OH
2-Pyridinecarbaldehyde
Acetophenone
64
50
7
8
9
14
12
2.5
38
O
OH
OMe
OMe
(C6H5)2CHOH
(C6H5)2C@O
100
100
O
O
10
OH
O
11
12
C6H5CH@CHCH2OH
(C6H5)2CH2
C6H5CH@CHCHO
–
14
45
64
N.R.d
OH
13
–
45
N.R.d
a
Reaction conditions: substrate (1 mmol), catalyst (0.1 mmol), K2CO3 (2 mmol), in 2.5 ml NMP at 110 ꢁC, under O2 (1 atm); catalyst was in situ
prepared by mixing 1 and CuCl.
b
Complex 6 as catalyst.
Based on NMR integration.
No reaction.
c
d

W. Tsai et al. / Journal of Organometallic Chemistry 690 (2005) 415–421
419
3. Conclusion
MHz, CDCl3): d 156.8, 155.8, 149.3, 148.0, 146.8,
146.7, 144.1, 135.8, 135.7, 133.6, 133.5, 132.7, 132.3,
132.2, 131.7, 131.7, 131.6, 128.4, 128.3, 123.3, 123.1,
123.0, 122.4, 122.3, 122.0, 121.0, 120.3, 120.2, 119.6,
110.3; 31P NMR (162 MHz, CDCl3): d 36.9. Anal.
Calc. for C30H24N3OP: C, 76.10; H, 5.11; N, 8.87.
Found: C, 75.59; H, 5.10; N, 8.66%.
In summary, this new polydentate ligand gave the
formation of square-pyramidal copper(II) complexes
with all three nitrogen donors in facial arrangement.
These copper(II) complexes showed no catalytic activity
in oxidation of alcohols, but the copper(I) complex may
oxidize benzylic alcohols into the corresponding carbo-
nyl compounds.
4.2.2. Ligand 1
A mixture of 2 (4.58 g, 9.67 mmol), 10% Pd/C (1.03 g,
0.97 mmol) in 30 ml methanol was pressurized with
hydrogen gas (20 psi). After stirring for 48 h at rt, the
reaction mixture was filtered through celite, concen-
trated and re-dissolved in dichloromethane. The hydro-
genated product was obtained as a white solid (4.4 g,
96%) by addition of diethyl ether; m.p. 101–102 ꢁC;
1H NMR (400 MHz, CDCl3): d 8.50 (d, J = 4.4 Hz,
1H, ArH), 8.40 (d, J = 4.4 Hz, 1H, ArH), 7.71 (d,
J = 6.0 Hz, 1H, ArH), 7.64–7.41 (m, 11H, ArH), 7.31
(t, J = 7.6 Hz, 1H, ArH), 7.06–6.92 (m, 3H, ArH),
6.71 (dd, J = 14.6, 7.5 Hz, 1H, ArH), 6.46–6.41 (m,
2H, ArH), 4.99 (br, 1H, –CH–), 3.32 (dd, J = 13.6, 4.6
Hz, 1H, –CH2–), 3.13 (dd, J = 13.6, 8.8 Hz, 1H,
–CH2–), 2.75 (s, 1H, –NH–); 13C NMR (100 MHz,
CDCl3): d 162.3, 157.8, 151.9, 149.1, 148.9, 136.7,
136.1, 133.5, 133.3, 132.3, 132.2, 132.1, 132.0, 131.8,
128.5, 128.4, 128.4, 128.3, 124.0, 121.9, 121.3, 120.4,
115.4, 115.3, 112.5, 112.4, 59.4, 45.2; 31P NMR (162
4. Experimental
4.1. General
All reactions, manipulations and purifications steps
were performed under a dry nitrogen atmosphere.
Tetrahydrofuran was distilled under nitrogen from so-
dium benzophenone ketyl. Dichloromethane and aceto-
nitrile were dried with CaH2 and distilled under
nitrogen. Other chemicals and solvents were of analyti-
cal grade and were used as received unless otherwise
stated.
Nuclear magnetic resonance spectra were recorded in
CDCl3 on either a Bruker AM-300 or AVANCE-400
spectrometer. Chemical shifts are given in parts per mil-
lion relative to Me4S for 1H and relative 85% H3PO4 for
31P NMR. Infrared spectra were measured on a BioRad
FTS-40 spectrometer (Series-II) as KBr pallets, unless
otherwise noted. UV–Vis spectra were determined on a
U-3010 spectrophotometer. EPR spectra at X-band fre-
quency were recorded with a Brucker ESP 300
spectrometer.
MHz, CDCl3):
d
36.1; HRMSFAB Calc. for
C30H26N3OP: m/z = 475.1813. Found: 475.1825; Anal.
Calc. for C30H26N3OP: C, 75.77; H, 5.51; N, 8.84.
Found: C, 75.58; H, 5.15; N, 8.38%.
4.2.3. Complex 4
4.2. Synthesis and characterization
A solution of CuCl2 (30 mg, 0.22 mmol) in absolute
ethanol (1 ml) was added to a solution of ligand 1
(106 mg, 0.22 mmol) in absolute ethanol (2 ml) under
nitrogen atmosphere. The resulting mixture was heated
to reflux for 3 h. The volume of the solvent was reduced
down to 0.5 ml under vacuum. Addition of ether to the
solution gave the complex as a green precipitates (40.1
mg, 29.5%). Anal. Calc. for C34H36Cl2CuN3O2-
P(4 + ether): C, 59.69; H, 5.30; N, 6.14. Found: C,
59.28; H, 4.98; 5.97%.
4.2.1. Compound 2
To a 50 ml round bottom flask was placed o-
(diphenylphosphinyl)aniline [14] (1.21 g, 4.4 mmol)
and 2-pyridinecarbaldehyde (1.0 g, 9.3 mmol) in meth-
anol (15 ml) under the degassed conditions. The mix-
ture was heated in the oil bath at 55 ꢁC for 5 h. After
the completion of the reaction, the mixture was con-
centrated and dissolved in dichloromethane. Upon
the addition of hexane to the solution, the desired
product was precipitated as a white solid (1.88 g,
1
91%): m.p. 200–201 ꢁC; H NMR (400 MHz, CDCl3):
4.2.4. Complex 5
d 11.56 (s, 1H, –HN–C), 8.55 (d, J = 4.8 Hz, 1H,
ArH), 8.32 (d, J = 4.8 Hz, 1H, ArH), 7.86–7.81 (m,
4H, –ArH), 7.54–7.45 (m, 7H, ArH), 7.27 (td,
J = 6.9, 1.4 Hz, 1H, ArH), 7.20 (td, J = 7.6, 1.7 Hz,
1H, ArH), 7.11 (d, J = 8.0 Hz, 1H, ArH), 7.04–7.01
(m, 2H, ArH), 6.92 (dd, J = 7.4 Hz, 5.0 Hz, 1H,
ArH), 6.78 (td, J = 7.4, 1.4 Hz, 1H, ArH), 6.39 (dd,
J = 8.1, 4.9 Hz, 1H, ArH), 6.25 (d, J = 7.8 Hz, 1H,
Ar H), 6.23 (s, 1H, –HC@C–); 13C NMR (100
A solution of ligand 1 (75 mg, 0.16 mmol) in metha-
nol (2 ml) was slowly added to a solution of Cu-
(ClO4)2 Æ 6H2O (58.5 mg, 0.16 mmol) in methanol
(1 ml) with stirring. After stirring 2 h, the reaction mix-
ture was concentrated to a volume of 0.5 ml. Upon addi-
tion of ether, the desired complex was precipitated as a
green solid (92 mg, 77%). Anal. Calc. for C34H38Cl2Cu-
N3O11P(5 +ether): C, 49.19; H, 4.61; N, 5.06. Found C,
49.01; H, 4.22; N, 4.87%.

420
W. Tsai et al. / Journal of Organometallic Chemistry 690 (2005) 415–421
Table 3
Crystal data of 1, 4 and 5
Compound
1
4
5
Formula
C30H24N3OP
473.49
C34H36Cl2CuN3O2P
684.07
C34H38Cl2CuN3O11
830.08
P
Formula weight
Crystal system
Space group
Monoclinic
P21/n
Monoclinic
P21/c
Orthorhombic
P212121
˚
a (A)
9.9070(1)
16.3410(2)
14.2250(2)
15.3980(2)
10.0940(3)
17.608(1)
21.288(1)
90
˚
b (A)
˚
c (A)
29.8970(4)
90
15.4600(2)
90
a (ꢁ)
b (ꢁ)
c (ꢁ)
99.057(1)
90
4779.7(1)
91.489(1)
90
3385.16(8)
90
90
3
˚
V (A )
3783.6(3)
4
1.457
Z
8
1.316
1984
4
1.342
1420
Dcalc (Mg/m3)
F(000)
1716
Crystal size (mm)
h Range
0.25 · 0.20 · 0.20
1.38–27.50
60,745
0.30 · 0.25 · 0.10
4.94–27.43
26,525
0.25 · 0.20 · 0.10
2.78–25.01
18,991
Reflection collected
Independent reflection (Rint
Refined method
R [I > 2r(I)]
)
10,960 (0.0710)
Full-matrix least-squares on F2
R1 = 0.0645; wR2 = 0.1648
1.092
7642 (0.0535)
Full-matrix least-squares on F2
R1 = 0.0543; wR2 = 0.0912
1.012
6592 (0.1152)
Full-matrix least-squares on F2
R1 = 0.0682; wR2 = 0.1385
1.024
Goodness-of-fit on F2
4.2.5. Complex 6
e-mail: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk).
To a solution of CuCl (37 mg, 0.37 mmol) in anhy-
drous acetonitrile was added a solution of ligand 1
(178 mg, 0.37 mmol) in acetonitrile. The resulting solu-
tion was stirred at room temperature for 1 h. The de-
sired complex was obtained in brown-red color
solid,which was further purified by precipitation from
dichloromethane/ether (185 mg, 86%); m.p. 118 ꢁC
Acknowledgements
The authors thank Professor C.-Y. Mou as well as
T.T. Lin for their advice in epr determination. We also
gratefully acknowledge the support for this work from
the National Science Council, Taiwan (Grant No.
NSC92-2113-M-002-040).
1
(dec.); H NMR d 8.50 (br, 1H, ArH), 8.40 (br, 1H,
ArH), 7.73–7.44 (m, 11H, ArH), 7.12–6.99 (br, 6H,
ArH), 6.71 (dd, J = 14.6 Hz, 7.5 Hz, 1H, ArH), 6.46–
6.41 (m, 2H, ArH), 4.98 (br, 1H, –CH–), 3.30 (br, 1H,
–CH2–), 3.12 (br, 1H, –CH2–), 2.54 (s, 1H, –NH–); 31P
NMR d 36.3. Anal. Calc. for C30H26ClCuN3OP: C,
62.72; H, 4.56; N, 7.31. Found: C, 62.45; H, 4.22; N,
7.02%.
References
[1] A.L. Gavrilova, B. Bosnich, Chem. Rev. 104 (2004) 349.
[2] (a) W.B. Tolman, Acc. Chem. Res. 30 (1997) 227;
(b) J.A. Halfen, V.G. Young, W.B. Tolman, Angew. Chem. Int.
Ed. 35 (1996) 1687;
4.3. X-ray crystallographic analysis
(c) J.A. Halfen, B.A. Jazdzewski, S. Mahapatra, L.M. Berreau,
E.C. Wilkinson, L.J. Que, W.B. Tolman, J. Am. Chem. Soc. 119
(1997) 8217 (references therein).
Crystals suitable for X-ray determination were ob-
tained for 1, 4 Æ ether and 5 Æ ether by slow diffusion of
diethyl ether into a methanol solution at room tempera-
ture. Cell parameters were determined either by a Sie-
mens SMART CCD diffractometer. Crystal data of
these complexes are listed in Table 3 and ORTEP plots
of 1, 4 and cationic part of 5 are shown in Figs. 1–3,
respectively (Labels of phenyl groups are omitted for
clear view). Other crystallographic data have been
deposited with the Cambridge Crystallographic Data
Center: CCDC 233664–233666 for 1, 4 and 5, respec-
tively. Copies of this information can be obtained free
of charge and by application to CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK (fax: + 44 1223/336033;
[3] (a) N. Kitajima, K. Fujisawa, Y. Moro-oka, J. Am. Chem. Soc.
111 (1989) 8975;
(b) N . Kitajima, K. Fujisawa, C. Fujimoto, Y. Moro-oka, S.
Hashimoto, T. Kitagawa, K. Toriumi, K. Tatsumi, A. Nakamura,
J. Am. Chem. Soc. 114 (1992) 1277 (references therein).
[4] (a) E. Pidcock, H.V. Obias, M. Abe, H.C. Liang, K.D. Karlin,
E.I. Solomon, J. Am. Chem. Soc. 121 (1999) 1299;
(b) E. Pidcock, S. DeBeer, H.V. Obias, B. Hedman, K.O.
Hodgson, K.D. Karlin, E.I. Solomon, J. Am. Chem. Soc. 121
(1999) 1870;
(c) H.V. Obias, Y. Lin, N.N. Murthy, E. Pidcock, E.I. Solomon,
M. Ralle, N.J. Blackburn, Y.-M. Neuhold, A.D. Zuberbuhler,
K.D. Karlin, J. Am. Chem. Soc. 120 (1998) 12960.
[5] (a) W.E. Lynch, D.M.J. Kurtz, S. Wang, R.A. Scott, J. Am.
Chem. Soc. 116 (1994) 11030;

W. Tsai et al. / Journal of Organometallic Chemistry 690 (2005) 415–421
421
(b) T.N. Sorrell, W.E. Allen, P.S. White, Inorg. Chem. 34 (1995)
952.
(d) A. Philibert, F. Thomas, C. Philouze, S. Hamman, E. Saint-
Aman, J.-L. Pierre, Chem. Eur. J. 9 (2003) 3803.
[9] (a) B.G. Malmstrom, Annu. Rev. Biochem. 51 (1982)
21;
[6] M.M. Whittaker, Y.-Y. Chuang, J.W. Whittaker, J. Am. Chem.
Soc. 115 (1993) 10029.
[7] (a) S. Itoh, S. Takayama, R. Arakawa, A. Furuta, M. Komatsu,
A. Ishida, S. Takamuku, S. Fukuzumi, Inorg. Chem. 36 (1997)
1407;
(b) D. Cerdemann, C. Eicken, B. Krebs, Acc. Chem. Res. 35
(2002) 183.
[10] S. Doherty, J.G. Knight, T.H. Scanlan, M.R.J. Elsegood, W.
Clegg, J. Organomet. Chem. 650 (2002) 231.
[11] S.J. Brudenell, L. Spiccia, A.M. Bond, P. Comba, D.C.R.
Hockless, Inorg. Chem. 37 (1998) 3705.
(b) S. Itoh, M. Taki, S. Fukuzumi, Coord. Chem. Rev. 198 (2000) 3.
[8] (a) H. Adams, N.A. Bailey, I.K. Campbell, D.E. Fenton, Q.-Y.
He, J. Chem. Soc., Dalton Trans. (1996) 2233;
(b) T.K. Paine, T. Weyhermueller, K. Wieghardt, P. Chaudhuri,
Dalton Trans. (2004) 2092;
[12] W. Henke, S. Kremer, D. Reinen, Inorg. Chem. 22 (1983)
2858.
(c) L. Benisvy, A.J. Blake, D. Collison, E.S. Davies, C.D. Garner,
E.J.L. McInnes, J. McMaster, G. Whittaker, C. Wilson, Dalton
Trans. (2003) 1975;
[13] G.A. McLachlan, G.D. Fallon, R.L. Martin, L. Spiccia, Inorg.
Chem. 34 (1995) 254.
[14] J. Copper, J. Powell, Inorg. Synth. 25 (1989) 129.