Copper(I) monophosphine complexes with functionalized acylpyrazolonate ligands: Syntheses of heterobimetallic Cu-Zn and Cu-Ru adducts

Article abstract of DOI:10.1016/j.poly.2005.07.020

Copper(I) acylpyrazolonate derivatives of formula [Cu(Q)(PPh ₃)₂] (HQ = HQ^C2F5 = 1-phenyl-3-methyl-4- pentafluoropropanoylpyrazol-5-one, HQ^CF3,CF3 = 1-(4-trifluoromethyl) phenyl-3-methyl-4-trifluoroacetylpyrazol

Full text of DOI:10.1016/j.poly.2005.07.020

Polyhedron 25 (2006) 124–133
www.elsevier.com/locate/poly
Copper(I) monophosphine complexes with functionalized
acylpyrazolonate ligands: Syntheses of heterobimetallic Cu–Zn and
Cu–Ru adducts
a
a,
a
a
Augusto Cingolani , Fabio Marchetti *, Claudio Pettinari , Riccardo Pettinari ,
b
b
b
Brian W. Skelton , Neil Somers , Allan H. White
a
`
Dipartimento di Scienze Chimiche, Universita degli Studi di Camerino, via S. Agostino 1, 62032 Camerino, Italy
School of Biomolecular, Biomedical and Chemical Sciences, Chemistry M313, The University of Western Australia, Crawley, W. A. 6009, Australia
b
Received 8 June 2005; accepted 12 July 2005
Available online 13 September 2005
Abstract
Copper(I) acylpyrazolonate derivatives of formula [Cu(Q)(PPh3)2] (HQ = HQC2F5 = 1-phenyl-3-methyl-4-pentafluoropropanoyl-
pyrazol-5-one, HQCF3,CF3 = 1-(4-trifluoromethyl)phenyl-3-methyl-4-trifluoroacetylpyrazol-5-one, HQnaph = 1-phenyl-3-methyl-4-
(1-naphthoyl)pyrazol-5-one, HQfur = 1-phenyl-3-methyl-4-furylpyrazol-5-one, HQthi = 1-phenyl-3-methyl-4-thienoylpyrazol-5-one,
HQCF3,py = 1-(2-pyridyl)-3-methyl-4-trifluoromethylpyrazol-5-one) have been synthesized and characterized, both in the solid state
and in solution. The isomorphous crystal structures of [Cu(Qfur)(PPh3)2] and [Cu(Qthi)(PPh3)2] and of [Cu(QC2F5)(PPh3)2] show their
copper atoms in distorted tetrahedral environments. Apart from the derivative [Cu(Qnaph)(PPh3)2], they are fluxional in chloroform
solution, dissociating partially to the [Cu(Q)(PR3)] fragment and free PR3, or existing in solution as [Cu(O2–Q)(PR3)2] or [Cu(O–Q)-
(PR3)2] species, with CuO2P2 or CuOP2 metal environments, in equilibrium with each other. By contrast, in [Cu(QCF3,py)(PPh3)2] the
QCF3,py ligand is coordinated to copper through the nitrogen atoms of the pyrazole and pyridine rings. The latter compound reacts
with Zn(BF4)2 Æ xH2O and [Ru(p-cymene)Cl2]2 affording ionic heterobimetallic adducts.
ꢀ 2005 Elsevier Ltd. All rights reserved.
Keywords: Copper; 4-Acyl-5-pyrazolones; Crystal structures; Heterobimetallic derivatives
1. Introduction
[4,5]. Furthermore they have been shown capable of
binding also to soft metal acceptors through the nitro-
gen of the pyrazole [6]. These ligands can be easily func-
tionalized in the acyl fragment and several examples can
be found in the literature, in which the substituents
range from electron-withdrawing groups to electron-
donating ones [1].
We have also investigated the coordination chemistry
of some acylpyrazolone-type ligands with copper(I) and
copper(II) acceptors, due to potential applications in the
microelectronic industry of some recent copper–b-diketo-
nate compounds as promising molecular precursors for
CVD techniques [7]. When heated in vacuo, copper(II)
adducts of the type Cu(Q)2(L) (where L = dipy or phen
In the last decade we have been involved in elucidat-
ing the coordinative properties of a class of b-diketones,
namely 4-acyl-5-pyrazolones [1], here indicated as HQ,
having a pyrazole fused to the chelating moiety, well-
known mainly for their selective extraction properties
toward several metal ions [2,3]. They generally chelate
metal centers in an unsymmetrical fashion because of
the different donor capabilities of their oxygen atoms
*
Corresponding author. Tel.: +39 0737 402217; fax: +39 0737
637345.
E-mail address: fabio.marchetti@unicam.it (F. Marchetti).
0277-5387/$ - see front matter ꢀ 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2005.07.020

A. Cingolani et al. / Polyhedron 25 (2006) 124–133
125
CF3
O
S
CF2
CF3
CF3
6
6
6
4
6
4
6
6
Me
Me
3
Me
Me
O
Me
3
Me
O
O
O
O
O
4
3
3
3
3
4
4
4
N2
N2
N2
N2
N2
N2
O
O
O
O
O
5
O
5
5
5
5
5
N1
1
N
N1
N1
N1
N1
N
CF3
HQCF3,CF3
HQnaph
HQthi
HQCF3,py
HQC2F5
HQfur
Fig. 1. Proligands HQ used in this work.
and Q = 1-phenyl-3-methyl-4-trifluoromethyl-pyrazo-
lon-5-ato) eliminate the ancillary L ligand and convert
into Cu(Q)2, which have lower volatilities than their cor-
responding classical b-diketonato copper(II) complexes
[8]. Cu(I) derivatives of the form Cu(Q)(PR3)2 (R =
Ph, Cy, Bn, p-tolyl) show higher volatility, and during
sublimation form a thin film of metallic copper, accord-
ing to the disproportionation: 2 Cu(Q)(PR3)2 ! Cu +
Cu(Q)2 + 4PR3 [8].
300 Varian spectrometer operating at room temperature
1
(300 MHz for H, 75 MHz for 13C, 282.3 MHz for 19F
and 121.4 MHz for 31P) and are referred to TMS, 85%
H3PO4 and CFCl3, respectively; signals are indicated
as s (singlet), d (doublet), t (triplet), q (quartet), m (mul-
tiplet). The electrical conductances of the acetonitrile
solutions were measured with a Crison CDTM 522 con-
ductimeter at room temperature.
Here we extend previous studies on the interaction of
copper(I) and silver(I) phosphino acceptors [6a,6b,9]
with some selected acylpyrazolones, two containing
fluorinated substituents, others with aromatic groups
such as naphthyl, furanyl or thienyl in the acyl moiety
and, finally, a ligand containing a pyridine ring bonded
to N1 of the pyrazolone moiety (Fig. 1), recently re-
ported as an N2-chelating donor in the synthesis of
new silver compounds [10]. A detailed structural and
spectroscopic study of the derivatives obtained is re-
ported, and comparison made with the features of the
previously studied silver(I) phosphino acylpyrazolonates
[6a,6b,9,10]. Possible further interactions through any
additional N-, S- or O-donor atoms in QCF3,py, Qthi or
Qfur, respectively, with additional metal acceptors, such
as zinc(II) and (arene)ruthenium(II), have also been
investigated.
2.2. Syntheses of the proligands
The proligands HQC2F5, HQCF3,CF3, HQnaph, HQfur
,
HQthi and HQCF3,py were synthesized according to the
procedures previously described [6b,9–13].
2.3. Syntheses of the complexes
2.3.1. [Cu(QC2F5)(PPh3)2] (1)
CuNO3(PPh3)2 (650 mg, 1.0 mmol) was added to a
toluene solution/suspension (30 ml) of HQC2F5 (320 mg,
1.0 mmol) and NaOCH3 (54 mg, 1.0 mmol). The clear
solution was stirred for 1 h. Solvent was then removed
on a rotary evaporator and chloroform (20 ml) was
added to the crude of the mixture reaction. The solution
was filtered and, after addition of light petroleum (20 ml),
a yellow precipitate was afforded, which was filtered off,
washed with light petroleum and shown to be compound
1. Crystals suitable for the X-ray work were deposited
from chloroform/diethyl ether solution. It is soluble in
most organic solvents, except petroleum ether. Yield:
84%. M.p. 142–144 ꢁC. Anal. Calc. for C49H38CuF5-
N2O2P2: C, 64.86; H, 4.22; N, 3.09. Found: C, 63.95;
H, 4.09; N, 3.01%. IR (nujol, cmꢀ1): 1636vs, 1597s,
1584s and 1542m m(C@O, C@N, N@N), 517vs, 503vs,
497vs, 443m, 430m and 426m m(y- and t-mode of PPh3),
2. Experimental section
2.1. General remarks
Solvents were used as supplied or distilled using stan-
dard methods. All chemicals were purchased from
Aldrich (Milwaukee) and used as received. The samples
for microanalyses were dried in vacuum to constant
weight (20 ꢁC, ca. 0.1 Torr). Elemental analyses (C, H,
N, S) were performed in-house with Fisons Instruments
1108 CHNS–O Elemental Analyser. IR spectra were re-
corded from 4000 to 100 cmꢀ1 using CsI pellets and a
1
397w and 345m m(Cu–O). H (CDCl3) NMR: d 2.25s
(3H, C3–CH3); 7.20–7.50m, 7.90d (35H, Harom of
QC2F5 and PPh3). 13C{1H} NMR (CDCl3): d, 17.4s
(C3–CH3), 120.0s, 124.2s, 128.5s, 148.1s (Carom of
QC2F5), 129.5d (3J(P–C): 14.1 Hz, m-C of PPh3), 129.9s
(p-C of PPh3), 133.2d (1J(P–C): 36.1 Hz, C–P of PPh3),
134.0d (2J(P–C): 21.7 Hz, o-C of PPh3), 104.6s (C4),
1
Perkin Elmer System 2000 FT-IT instrument. H, 13C,
19F and 31P NMR spectra were recorded on a VXR-

126
A. Cingolani et al. / Polyhedron 25 (2006) 124–133
139.4s (C3), 165.8s (C5), 182.3s (C6), resonances of
CF2CF3 not observed. 31P{1H} NMR (CDCl3,
T = 293 K): d ꢀ2.42s. 31P{1H} NMR (CDCl3, T =
from chloroform/diethyl ether solution. Yield: 88%.
M.p. 168–170 ꢁC. Anal. Calc. for C51H41CuN2O3P2: C,
71.70; H, 4.72; N, 3.28. Found: C, 71.53; H, 4.66; N,
3.24%. IR (nujol, cmꢀ1): 1610vs, 1592s, 1581s, 1557m
and 1526m m(C@O), 516s, 505vs, 494s, 440m and
426m m(y- and t-mode of PPh3), 408m and 356m
m(Cu–O). 1H (CDCl3) NMR: d 2.61s (3H, C3–CH3),
6.64m, 6.88m, 7.10–7.45m, 7.49dd, 7.65dd, 7.73d (38H,
Harom of Qfur and PPh3). 13C{1H} NMR (CDCl3): d,
16.7s (C3–CH3), 111.4s, 114.4s, 119.9s, 123.5s, 143.6s,
154.0s (Carom of Qfur), 128.5d (3J(P–C): 6.9 Hz, m-C of
PPh3), 129.6s ( p-C of PPh3), 132.4d (1J(P–C): 27.1 Hz,
C–P of PPh3), 134.1d (2J(P–C): 14.8 Hz, o-C of PPh3),
104.8s (C4), 140.0s (C3), 167.2s (C5), 176.5s (C6).
31P{1H} NMR (CDCl3, T = 293 K): d ꢀ2.20s. 31P{1H}
218 K):
d
ꢀ0.46s [Cu(O2–QC2F5)(PPh3)], ꢀ1.84s
[Cu(O2–QC2F5)(PPh3)2], ꢀ3.63s [PPh3]. 19F{1H} NMR
(CDCl3,
T = 293 K):
d
ꢀ81.7s
(CF2CF3),
ꢀ115.7s(CF2CF3).
2.3.2. [Cu(QCF3,CF3)(PPh3)2] (2)
Compound 2 has been synthesized similarly to 1. It is
soluble in most organic solvents, except petroleum ether.
Yield: 69%. M.p. 182–184 ꢁC. Anal. Calc. for
C49H37CuF6N2O2P2: C, 63.63; H, 4.03; N, 3.03. Found:
C, 63.46; H, 4.25; N, 3.03%. IR (nujol, cmꢀ1): 1643vs,
1609s, 1586m, 1543m, 1518m and 1508s m(C@O, C@N,
N@N), 518vs, 504s, 488s, 461m, 447m and 434m m(y-
and t-mode of PPh3), 416w and 344m m(Cu–O). 1H
NMR (CDCl3, T = 218 K):
d
ꢀ2.68s [Cu(O–
Qfur)(PPh3)2], ꢀ4.04s [Cu(O2–Qfur)(PPh3)2].
2.3.5. [Cu(Qthi)(PPh3)2] (5)
6
(CDCl3) NMR: d 2.45q (3H, J(F–H): 2.2. Hz, C3–
CH3), 7.15–7.40m, (30H, Harom of PPh3), 7.49d, 7.99d
(4H, Harom of QCF3,CF3). 13C{1H} NMR (CDCl3): d,
16.4s (C3–CH3), 117.9q (1J(F–C): 284.7 Hz, CF3C@O),
118.9s, 125.5s, 128.7s, 148.2s (Carom of QCF3,CF3),
128.7d (3J(P–C): 13.5 Hz, m-C of PPh3), 129.9s (p-C of
PPh3), 132.9d (1J(P–C): 34.4 Hz, C–P of PPh3), 133.9d
(2J(P–C): 20.2 Hz, o-C of PPh3), 100.7s (C4), 142.1s
(C3), 168.1s (C5), 183.9s (C6), resonances of N–C6H4–
p-CF3 not observed. 31P{1H} NMR (CDCl3,
T = 293 K): d ꢀ2.49s. 31P{1H} NMR (CDCl3, T =
Compound 5 has been synthesized similarly to 1,
crystals suitable for the X-ray work being deposited
from chloroform/diethyl ether solution. Yield: 79%.
M.p. 159–161 ꢁC. Anal. Calc. for C51H41CuN2O2P2S:
C, 70.29; H, 4.74; N, 3.21; S, 3.68. Found: C, 69.87;
H, 4.79; N, 3.22; S, 3.55%. IR (nujol, cmꢀ1): 1609vs,
1592s, 1579s, 1554m and 1516m m(C@O), 515vs, 504vs,
498vs, 440m, 431m and 424m m(y- and t-mode of
1
PPh3), 405w and 353m m(Cu–O). H (CDCl3) NMR: d
218K):
d
ꢀ1.45s [Cu(O–QCF3,CF3)(PPh3)2], ꢀ3.11s
1.91s (3H, C3–CH3); 6.97t, 7.05t, 7.15t, 7.22–7.40m,
7.88d (38H, Harom of Qthi and PPh3). 13C{1H} NMR
(CDCl3): d, 16.9s (C3–CH3), 119.7s, 123.4s, 126.3s,
145.1s, 148.2s (Carom of Qthi), 128.2d (3J(P–C): 7.1 Hz,
[Cu(O2–QCF3,CF3)(PPh3)2]. 19F{1H} NMR (CDCl3,
T = 293 K):
((C@O)CF3).
d
ꢀ62.3s (N–C6H4–p-CF3), ꢀ72.0s
m-C of PPh3), 129.4s (p-C of PPh3), 133.2d (1J(P–C)
:
2.3.3. [Cu(Qnaph)(PPh3)2] (3)
27.3 Hz, C–P of PPh3), 133.8d (2J(P–C): 14.1 Hz, o-C of
PPh3), 104.9s (C4), 139.9s (C3), 166.2s (C5), 181.4s
(C6). 31P{1H} NMR (CDCl3, T = 293 K): d ꢀ2.62s.
31P{1H} NMR (CDCl3, T = 218 K): d ꢀ2.64s [Cu(O–
Qthi)(PPh3)2], ꢀ4.17s [Cu(O2–Qthi)(PPh3)2].
Compound 3 has been synthesized similarly to 1. It is
soluble in dmso, acetonitrile, acetone and chlorinated
solvents. Yield: 88%. M.p. 204–207 ꢁC. Anal. Calc. for
C57H46CuN2O2P2: C, 74.70; H, 5.06; N, 3.06. Found:
C, 74.45; H, 5.10; N, 3.11%. IR (nujol, cmꢀ1): 1621vs,
1592s, 1578m, 1532m and 1500m m(C@O), 528s, 515vs,
500vs, 437m and 420m m(y- and t-mode of PPh3),
2.3.6. [Cu(QCF3,py)(PPh3)2] (6)
Compound 6 has been synthesized similarly to 1, but
using a mixture of acetonitrile/methanol (1:1) because of
the very low solubility of HQCF3,py in toluene. Crystals
suitable for the X-ray work were deposited from chloro-
form/diethyl ether solution. Yield: 67%. M.p. 180–
183 ꢁC. Anal. Calc. for C47H37CuF3N3O2P2: C, 65.77;
H, 4.35; N, 4.90. Found: C, 65.43; H, 4.54; N, 4.88%.
IR (nujol, cmꢀ1): 1667vs, 1636s, 1621s, 1596m and
1534m m(C@O), 527s, 516vs, 512s, 494s, 446m, 422m
and 412m m(y- and t-mode of PPh3), 310s and 244m
m(Cu–N). 1H NMR (CDCl3): d 2.07s (3H, C3–CH3),
7.19m, 7.34d, 7.50m, 7.62m, 8.83d (34H, Harom of
QCF3,py and of PPh3). 13C{1H} NMR (CDCl3): d 18.5s
(C3–CH3), 113.5s, 118.9s, 139.0s, 146.6s, 150.3s (Carom
of QCF3,py), 128.9d (3J(P–C): 7.3 Hz, m-C of PPh3),
132.6d (1J(P–C): 38.7 Hz, C–P of PPh3), 130.2s (p-C of
1
343m m(Cu–O). H (CDCl3) NMR: d 1.21s (3H, C3–
CH3), 7.05–7.45m, 7.54d, 7.83dd, 7.97dd (37H, Harom
of Qnaft and PPh3). 13C{1H} NMR (CDCl3): d, 16.1s
(C3–CH3), 119.5s, 123.5s, 123.9s, 125.3s, 125.9s,
126.1s, 126.6s, 128.1s, 130.4s, 140.0s (Carom of Qnaph),
128.5d (3J(P–C): 17.6 Hz, m-C of PPh3), 129.6s (p-C of
PPh3), 133.4d (1J(P–C): 34.4 Hz, C–P of PPh3), 133.6d
(2J(P–C): 22.3 Hz, o-C of PPh3), 106.3s (C4), 140.4s
(C3), 165.9s (C5), 189.9s (C6). 31P{1H} NMR (CDCl3,
T = 293 K): d ꢀ3.43s [Cu(O2–Qnaph)(PPh3)2]. 31P{1H}
NMR (CDCl3, T = 218 K): d ꢀ4.15s.
2.3.4. [Cu(Qfur)(PPh3)2] (4)
Compound 4 has been synthesized similarly to 1,
crystals suitable for the X-ray work being deposited

A. Cingolani et al. / Polyhedron 25 (2006) 124–133
127
PPh3), 133.4d (2J(P–C): 33.1 Hz, o-C of PPh3), 99.8s (C4),
155.8s (C3), 164.3s (C5), 173.5m (C6), CF3C@O not ob-
served. 31P{1H} NMR (CDCl3, T = 293 K): d 1.1s.
31P{1H} NMR (CDCl3, T = 218 K): d 0.5s [Cu(N2–
QCF3,py)(PPh3)2]. 19F{1H} NMR (CDCl3, T = 293 K):
d ꢀ76.0s (CF3).
m(H2O), 1667m d(H2O), 1651vs, 1644vs, 1637vs, 1605s,
1568m, 1557m and 1531m m(C@O), 840vs, 695s m(PF6),
527s, 512vs, 494s, 435m, 424m m(y- and t-mode of
PPh3), 460m m(Ru–O), 299m m(Ru–Cl), 251m m(Cu–N).
1H NMR (CD3CN): d 1.12s, 1.15s, 1.34s, 1.36s, 1.37s,
1.39s (6H, CH3–C6H4–CH(CH3)3), 1.73s, 1.88s, 1.94s
(3H, CH3–C6H4–CH(CH3)3), 1.99s, 2.27s, 2.31s (3H,
C3–CH3), 2.72m, 2.88m, 3.03m (1H, CH3–C6H4–
CH(CH3)3), 4.63d (AA0), 5.93d (BB0), 5.01d (AA0),
5.26d (BB0), 5.38d (AA0), 6.15d (BB0) (4H, CH3–
C6H4–CH(CH3)3), 7.18m, 7.38m, 7.55m, 7.61m, 7.81m
8.75m (34H, Harom of Qpy and of PPh3). 13C{1H}
NMR (CD3CN): d 18.0s, 18.5s, 18.6s (C3–CH3), 21.3s,
22.1s, 22.4s, 22.7s, 23.5s, 23.7s (CH3–C6H4–CH(CH3)3),
30.6s, 31.4s, 34.0s (CH3–C6H4–CH(CH3)3), 84.7s, 86.1s,
87.8s, 88.9s, 89.4s, 90.0s (CH3–C6H4–CH(CH3)3),
113.8s, 119.6s, 140.8s, 147.0s, 151.7s (Carom of Qpy),
2.3.7. [Zn{Cu(QCF3,py)(PPh3)2}3(BF4)2] Æ 2H2O (7)
Zn(BF4)2 Æ xH2O (80 mg, 0.3 mmol) was added to an
acetonitrile solution (50 ml) of compound 6 (858 mg,
1 mmol). The clear violet solution was stirred at reflux
for 4 h; solvent was then removed on a rotary evapora-
tor and the crude product treated with chloroform/
diethyl ether (1:1) (20 ml). A red-brown precipitate
was afforded, which was filtered off, washed with diethyl
ether (20 ml), dried to constant weight under reduced
pressure and shown to be compound 7. It is soluble in
dmso and acetonitrile. Yield: 85%. M.p. 156–158 ꢁC.
Anal. Calc. for C141H115B2Cu3F17N9O8P6Zn: C, 59.42;
H, 4.07; N, 4.42. Found: C, 59.78; H, 4.14; N, 4.10%.
Km (MeCN, 10ꢀ3 M): 288 Xꢀ1 cm2 molꢀ1. IR (nujol,
128.2d (3J(P–C): 9.8 Hz, m-C of PPh3), 128.9d (3J(P–C)
:
10.2 Hz, m-C of PPh3), 130.6s (p-C of PPh3), 131.7s
(p-C of PPh3), 132.2d (1J(P–C): 36.1 Hz, C–P of PPh3),
132.5d (1J(P–C): 36.6 Hz, C–P of PPh3), 134.5d (2J(P–C)
:
cmꢀ1): 3450br m(H2O), 1678m
d
(H2O), 1659vs,
29.8 Hz, o-C of PPh3), 134.8d (2J(P–C): 20.2 Hz, o-C of
PPh3), 96.5s (C4), 155.8s (C3), 165.3s (C5), 175.4m
(C6), CF3C@O not observed. 31P{1H} NMR (CD3CN,
T = 293 K): d 35.5s (PF6), 1.5s [(p-cymene)Ru(Cl)(j4-
O2,N2–QCF3,py) Cu(PPh3)2]. 19F{1H} NMR (CD3CN,
T = 293 K): d ꢀ72.6d (2J(P–F): 715.9 Hz, PF6), ꢀ76.0s
(CF3 in QCF3,py).
1651vs, 1644vs, 1634s, 1601s, 1585s, 1557m, 1537m
and 1519m m(C@O), 1057vs and 966s m(BF4), 528s,
518vs, 503s, 492s, 432m, 423m m(y- and t-mode of
PPh3), 441m m(Zn–O), 253m m(Cu–N). 1H NMR
(CD3CN): d 2.22s (9H, C3–CH3), 7.23m, 7.39m, 7.44d,
7.48d, 8.10m (102H, Harom of QCF3,py and of PPh3).
13C{1H} NMR (CD3CN): d 18.5s (C3–CH3), 113.6s,
119.5s, 140.5s, 146.9s, 150.9s (Carom of QCF3,py),
2.4. Structure determinations
129.4d (3J(P–C): 7.8 Hz, m-C of PPh3), 132.8d (1J(P–C)
:
38.9 Hz, C–P of PPh3), 130.3s (p-C of PPh3), 133.5d
(2J(P–C): 33.4 Hz, o-C of PPh3), 101.0s (C4), 151.2s
(C3), 165.8s (C5), 175.1m (C6), CF3C@O not observed.
Full spheres of ꢀlow-temperatureꢁ CCD diffractometer
data were measured (Bruker AXS instrument, mono-
˚
chromatic Mo Ka radiation (k = 0.71073 A), x-scans;
31P{1H} NMR (CD3CN, T = 293 K):
d
1.2s
T ca. 153 K), yielding Nt(otal) reflections, merging to N
unique after ꢀempiricalꢁ/multiscan absorption correction
(proprietary software), No with F > 4 (F) considered ꢀob-
servedꢁ and used in the full matrix least squares refine-
ments, refining anisotropic displacement parameter
[Zn{Cu(QCF3,py)(PPh3)2}3]. 19F{1H} NMR (CD3CN,
T = 293 K): d ꢀ76.1s (CF3 in QCF3,py), ꢀ151.8s (BF4).
2.3.8. [(p-cymene)Ru(Cl)(j4-O2, N2–QCF3,py)-
Cu(PPh3)2]PF6 Æ 3H2O (8)
forms for the non-hydrogen atoms, (x,y,z,Uiso)H being
[Ru(p-cymene)Cl2]2 (306 mg, 0.5 mmol) was added to
an acetonitrile solution (50 ml) of compound 6 (858 mg,
1 mmol). The orange-red solution was stirred at reflux
24 h, and AgPF6 (253 mg, 1.0 mmol) then added. A col-
ourless precipitate immediately formed, which was re-
moved by filtration. The volume of the filtrate was
then removed on a rotary evaporator and the crude
product treated with chloroform/petroleum ether (1:1)
(20 ml). A red-brown precipitate resulted, which was fil-
tered off, washed with petroleum ether (20 ml), dried to
constant weight under reduced pressure and shown to be
compound 8. It is soluble in dmso and acetonitrile.
Yield: 85%. M.p. 143–145 ꢁC. Anal. Calc. for
C57H57ClCuF9N3O5P3Ru: C, 51.55; H, 4.33; N, 3.16.
Found: C, 51.55; H, 4.42; N, 3.10%. Km (MeCN, 10ꢀ3
M): 136 Xꢀ1 cm2 molꢀ1. IR (nujol, cmꢀ1): 3420br
included constrained at estimates. Conventional residu-
als R, Rw (weights: (r2(F) + 0.000nwF2)ꢀ1) are cited at
convergence. Neutral atom complex scattering factors
were employed, computation using the XTAL 3.4 pro-
gram system [14]. Pertinent results are given below and
in the Tables and Figures, the latter showing non-hydro-
gen atoms with 50% probability amplitude displacement
ellipsoids, hydrogen atoms having arbitrary radii of
˚
0.1 A.
2.4.1. Crystal/refinement data
[Cu(QC2F5)(PPh3)2] (1). C49H38CuF5N2O2P2, M =
1
ꢀ
907.4. Triclinic, space group P1 (Ci , No. 2), a = 14.169(1),
˚
b = 19.140(2), c = 19.252(2) A, a = 118.414(2),
3
˚
b = 103.092(2), c = 99.222(2)ꢁ, V = 4248 A . Dc
(Z = 4) =1.419 g cmꢀ3
.
l
Mo = 6.5 cmꢀ1
;
specimen:

128
A. Cingolani et al. / Polyhedron 25 (2006) 124–133
3
0.26 · 0.22 · 0.18 mm; T0min/max = 0.65. 2hmax = 60ꢁ;
Nt = 87869, N = 24407 (Rint = 0.12), No = 14682; R =
0.075; Rw = 0.14 (nw = 850 (refinement on F2)).
8322 A . Dc (Z = 8) = 1.384 g cmꢀ3. lMo = 0.66 cmꢀ1
;
0
˚
specimen: 0.33 · 0.19 · 0.16 mm; 0T0min/max = 0.89.
2hmax = 55ꢁ; Nt = 119048, N = 19109 (Rint = 0.078),
No = 13181;
˚
0.70(5) eA .
Variata. Difference map residues in a lattice void were
modelled in terms of disordered methanol solvent C, O
fragments (H not located), site occupancies set at 0.25
after trial refinement. Neighbouring ligand substituent
residues also exhibit exalted displacement parameters,
possibly encompassing unresolved (concerted?) disorder.
ꢀ3
˚
|Dqmax| = 2.2(2) eA
.
R = 0.052;
Rw = 0.070.
|Dqmax| =
ꢀ3
Variata. The ligand on molecule 2 was modelled as
disordered over two sets of sites, occupancies refining
to 0.680(1) and complement, the geometries of the two
C2F5 components being constrained. P(22) and associ-
ated ring 223 were modelled as disordered over two sets
of sites, occupancies refining to 0.743(3) and
complement.
[Cu(Qfur)(PPh3)2] (4). C51H41CuN2O3P2, M = 855.4.
Orthorhombic, space group P212121 (D42, No. 19),
˚
a = 10.778(1), b = 18.872(2), c = 20.829(2) A, V =
3. Results and discussion
4237 A . Dc (Z = 4) = 1.341 g cmꢀ3. lMo = 6.4 cmꢀ1
;
3
˚
specimen: 0.15 · 0.12 · 0.10 mm; 0T0min/max = 0.70.
2hmax = 58ꢁ; Nt = 42477, N = 5987 (Rint = 0.071), No =
4264; R = 0.048; Rw = 0.052 (nw = 4). |Dqmax| =
3.1. Synthesis and spectroscopic characterization of the
derivatives
0.8(2) eAꢀ3. xabs = 0.02(2).
The new copper(I) derivatives 1–6 have been obtained
according to synthetic methods previously reported
(Scheme 1) [7].
˚
[Cu(Qthi)(PPh3)2] (5). C51H41CuN2O2P2S, M = 871.5
is isomorphous with 4, the specimen chosen being of
opposite chirality. a = 10.764(1), b = 19.015(2), c =
The choice of a mixture of acetonitrile/methanol in
the synthesis of derivative 6 being dictated by the solu-
bility of the proligand HQCF3,py. They are air-stable so-
lid compounds with sharp melting points, very soluble in
most organic solvents, as dmso, acetone, acetonitrile
aromatic and chlorinated solvents, in which they are
non-electrolytes.
The IR spectra of derivatives 1–5 show the typical
strong bands in the range 1500–1650 cmꢀ1, due to the
stretching modes of C@O, C@N and N@N of pyrazolo-
3
21.034(3) A, V = 4305 A . Dc = 1.344 g cmꢀ3. lMo
=
=
˚
˚
6.7 cmꢀ1; specimen: 0.38 · 0.35 · 0.20 mm; T0min/max
0
0.83. 2hmax = 58ꢁ; Nt = 43413, N = 6148 (Rint = 0.051),
No = 4722; R = 0.039; Rw = 0.037 (nw = 4). |Dqmax| =
0.6(1) eAꢀ3. xabs = ꢀ0.03(1).
˚
[Cu(QCF3,py)(PPh3)2] (6). 1/4MeOH„C47H38CuF3-
N3O2P2. 1/4 MeOH, M = 867.3. Monoclinic, space
group P21/n (C52h, No. 14), a = 23.771(2), b =
˚
15.797(2), c = 24.585(3) A, b = 115.657(2)ꢁ, V =
R
R
Me
O
Me
O
PPh3
Cu
+ NaOMe + CuNO3(PPh3)2
N
OH
N
N
Toluene/MeOH
O
N
PPh3
X
X
1, R = CF2CF3,
2, R = CF3,
3, R = 1-naphthyl,
4, R = 1-furyl,
X = H
X = CF3
X = H
X = H
5, R = 1-thienyl ,
X = H
O
F3C
Me
O
F3C
Me
N
+ N aOMe + C uNO3(PPh3)2
O
N
N
PPh3
PPh 3
OH
N
MeCN/MeOH
Cu
N
N
6
Scheme 1.

A. Cingolani et al. / Polyhedron 25 (2006) 124–133
129
nate ligands, slightly shifted upon coordination to lower
frequencies, the broad band between 2300 and
2800 cmꢀ1 in free HQ donors due to the O–Hꢁ ꢁ ꢁO moi-
ety having disappeared, in accordance with deprotona-
tion of the pyrazolonate [1,7]. In the low-frequency
region the typical bands due to the y- and t-modes of
vibration of triphenylphosphine have been detected at
400–530 cmꢀ1 [15], partially overlapped with two med-
ium Cu–O bands at ca 405 and 355 cmꢀ1 [16]. The IR
spectrum of 6 shows m(C@O) to be unchanged, in accor-
dance with coordination to copper through the two N
atoms of the pyrazole and pyridine rings, with the
Cu–N absorption bands at 310 and 244 cmꢀ1 [17].
Proton, fluorine, phosphorus and carbon NMR spec-
tra of 1–6 recorded at room temperature show a unique
broad set of resonances. The integration of the signals in
the proton spectra are in accordance with the formula-
tion proposed, i.e. with a 1:2 Q:PPh3 ratio. The low tem-
perature (218 K) 31P NMR spectrum of 1 exhibits three
resonances, one of them being the free phosphine, the
others, located at higher frequencies, being attributed
to copper–phosphino species of the type Cu(O2–
QC2F5)(PPh3)2 and Cu(O2–QC2F5)(PPh3), the latter
arising from dissociation of one PPh3 in solution, as pre-
viously found for similar copper derivatives [7a,7d].
The 31P NMR spectra of 2, 4 and 5 measured at low
temperature (218 K), show two resonances, consistent
with the presence of two different species, having
CuO2P2 and a CuOP2 metal environment, respectively,
the latter containing a Q ligand which seemingly acts
in an O-monodentate fashion [7c]. Finally the 31P
NMR spectra of 3 and 6 remains essentially unchanged
with respect to cooling of the samples at 218 K.
due to C–P coupling assists in the assignment of signals
arising from the C atoms of the phosphine ligand.
3.2. Structural studies
The results of structural characterisations by single
crystal X-ray studies of 4 and 5 are consistent in terms
of stoichiometry and connectivity with the above repre-
sentations, unsolvated (Fig. 2). The two complexes are
isomorphous with each other (single neutral molecules
comprising their asymmetric units), but not with their
silver(I) analogue [6b], the latter being modelled as a dis-
ordered array in which the pair of coordinated oxygen
sites may be interchanged. In none of the three adducts
is the substituent heterocycle chalcogen (O or S) found
to interact with any metal component of the structure,
and differences in the coordination environments of
the two complexes are trivial. Because of the irrelevance
of the substituent in this respect and the disorder in the
immediate silver–furyl counterpart, we adopt the phe-
nyl-substituted ligand analogue of the latter as a com-
parator. (The geometries of other relevant similar
silver(I) systems are also tabulated comparatively in
[9].) In that compound [6a], Ag–P are 2.475(3),
˚
2.465(3) and Ag–O 2.498(6) and 2.349(7) A; P–Ag–P is
120.9(1)ꢁ, O–Ag–O 73.0(2)ꢁ with O–Ag–P ranging be-
tween 92.1(2)–124.3(2)ꢁ, Ag–O exhibiting a much greater
disparity (the Ag–pyrazolone–O distance being the
longer) than the barely perceptible differences found in
the present copper complexes (Table 1). In the latter,
both P–M–P and O–M–O are enlarged relative to their
silver counterpart. In 4, 5, the pair of PPh3 ligands, of
the quasi-3 conformation, are of opposite chiralities
within each molecule, with the Qfur,thi non-hydrogen
skeletons approximately planar, except for a slight twist
The 13C NMR spectra of 1–6 exhibit one set of car-
bon resonances, and the presence of further doublets
Fig. 2. Projections of 4 and 5, normal to the Q skeletal planes, showing the reorientation of the heterocycle substituent within the pair of
isomorphous structures.

130
A. Cingolani et al. / Polyhedron 25 (2006) 124–133
Table 1
ously disordered silver derivative [6b]. Nevertheless the
Selected geometries, 4, 5, 1 (mol. 1)
non-disordered molecule provides useful data for a com-
plex derivative of a ligand with a fluorinated substituent
(Table 1), the Cu–O(4) distance adjoining the substitu-
ent being appreciably lengthened while Cu–O(5) is
slightly shortened, in keeping with the expectations
incumbent on the fluorinated substituent.
Atoms
Parameter
˚
Distances (A)
Cu–P(1)
Cu–P(2)
Cu–O(4)
Cu–O(5)
2.234(2), 2.246(1), 2.2597(9)
2.235(2), 2.240(1), 2.2567(9)
2.085(4), 2.098(3), 2.170(3)
2.077(4), 2.082(3), 2.059(4)
In 6, although the formulation is again confirmed to
be of the form [CuQ(PPh3)2], the nature of the complex
is quite different, presumably a consequence of the more
potent donor capability of the py substituent. In
[Cu(QCF3,py)(PPh3)2], 6, two independent neutral mole-
cules, accompanied by diverse solvent fragments in a lat-
tice void, comprise the asymmetric unit of the structure;
again the complex is not isomorphous with the recorded
unsolvated structure of its silver(I) analogue [10] which
is monoclinic, but with one independent molecule in
the asymmetric unit. In both copper and silver com-
plexes, the ligand QCF3,py now behaves as an N,N0-
rather than an O,O0-chelate, the N,N0-chelate ring being
five-membered rather than six, with the extended ligand
skeleton again quasi-planar (Fig. 4). In the silver(I) ad-
Angles (ꢁ)
P(1)–Cu–P(2)
P(1)–Cu–O(4)
P(1)–Cu–O(5)
P(2)–Cu–O(4)
P(2)–Cu–O(5)
O(4)–Cu–O(5)
127.16(6), 126.97(4), 125.02(4)
109.8(1), 110.26(8), 105.22(2)
105.4(1), 104.30(8), 100.96(7)
112.1(1), 112.36(8), 100.96(7)
106.2(1), 106.11(9), 116.76(7)
88.7(2), 89.5(1), 87.1(1)
Cu–P(C(nm1)–(ortho) torsion angles (ꢁ) (acute)
nm = 11
nm = 12
nm = 13
nm = 21
nm = 22
nm = 23
ꢀ36.4(5), 32.4(5), ꢀ30.9(5)
ꢀ53.5(5), 54.4(3), ꢀ48.7(4)
ꢀ41.0(5), 40.5(4), ꢀ57.6(3)
ꢀ35.5(5), 35.0(4), ꢀ45.1(4)
ꢀ29.5(6), 31.7(4), ꢀ58.5(3)
ꢀ56.8(6), 47.8(4), ꢀ31.8(5)
˚
duct Ag–P are 2.4585(7), 2.4494(7) A, only slightly
of the fur/thi ring planes, presumably in consequence of
the methyl proximity; interestingly, the substituent
planes adopt alternate dispositions in the two complexes
diminished cf. those of the Qfur analogue; Ag–N are
˚
2.400(2), 2.349(1) A (the latter shorter distance associ-
thi
˚
ated with the py donor) and P–Ag–P and N–Ag–N are
119.36(2)ꢁ and 68.59(6)ꢁ, respectively. In 6 (Table 2),
Cu–P are seen to be similar to the counterpart distances
in 4, 5; Cu–N distances are inequivalent with Cu–N(py)
the longer. The two molecules of 6 differ very signifi-
cantly in terms of their P–Cu–P angles and in a manner
which it is difficult to ascribe to anything other than a
considerable and unexpected sensitivity to ꢀpacking
forcesꢁ. The other significant difference between the
(Fig. 2): O(43)ꢁ ꢁ ꢁC(31) is 2.83(1) A, while in the Q
˚
derivative C(46)ꢁ ꢁ ꢁC(31) is 3.159(8) A, the determinant
of the twist presumably being the bulk of the sulphur
atom. They are thus not isostructural.
Complex 1 is also of the above type (Fig. 3); the
determination, although derivative of CCD data at
low temperature, shows two molecules in the asymmet-
ric unit, one having the ligand disordered by oxygen
interchange in the manner described above for the previ-
Fig. 3. Projection of derivative 1.
Fig. 4. Projection of 6 (molecule 1).

A. Cingolani et al. / Polyhedron 25 (2006) 124–133
131
Table 2
trile were always unsuccessful, whereas with derivative 6
the same reaction takes place, affording the ionic adduct
7 in high yield (Scheme 2), the difference in behaviour
being clearly due to the position of the additional het-
eroaromatic rings, in the acyl fragment for furyl and thi-
enyl in derivatives 4 and 5, and at N1 of the pyrazole for
2-pyridyl in derivative 6, where the N2-chelating face is
involved in the coordination of the {Cu(PPh3)2} frag-
ment, leaving both the carbonyl arms un-coordinated
and able to give additional interactions with new metal
acceptors.
Adduct 7 is a yellow solid with a sharp melting point.
The conductivity value of 288 Xꢀ1 cm2 molꢀ1 in acetoni-
trile is typical of 2:1 ionic species [18]. Moreover the
strong band at 1057 cmꢀ1 and a sharp one at
966 cmꢀ1 in the IR spectrum of 7, due to m4 and m3 of
BF4, shows no splitting or fine structure of the degener-
ate asymmetric vibrations, consistent with an ionic BF4
[19]. The most significant spectral feature in the IR of
adduct 7 is related to the red shift of m(C@O) with re-
spect to that found in derivative 6, in accordance with
the coordination of QCF3,py to the zinc through both
carbonyl arms. Finally, the resonances in the proton
and carbon NMR spectra of 7 show downfield shifts
due to the electron density flow toward the zinc centre.
We decided to investigate also the reactivity of deriv-
ative 6 toward an organometallic Lewis acid such as
Selected geometries, 6 (mols. 1,2)
Atoms
Parameter
˚
Distances (A)
Cu–P(1)
Cu–P(2)
Cu–N(2)
Cu–N(12)
2.249(1), 2.258(1)
2.252(1), 2.263(1)
2.045(3), 2.059(3)
2.107(3), 2.091(3)
Angles (ꢁ)
P(1)–Cu–P(2)
P(1)–Cu–N(2)
P(1)–Cu–N(12)
P(2)–Cu–N(2)
P(2)–Cu–N(12)
N(2)–Cu–N(12)
134.05(4), 120.89(4)
110.82(10), 117.94(10)
103.25(9), 107.73(8)
110.04(10), 108.36(10)
103.25(9), 115.30(10)
78.9(1), 79.2(1)
Cu–P(C(nm1)–C(ortho) torsion angles (ꢁ) (acute)
nm = 11
nm = 12
nm = 13
nm = 21
nm = 22
nm = 23
50.1(3), 40.3(4)
7.4(3), 45,7(3)
62.3(3), 29.3(4)
ꢀ8.3(4), 7.6(3)
ꢀ53.5(4), ꢀ47.3(3)
ꢀ62.2(3), ꢀ69.1(5)
two molecules is found in the PPh3 conformations –
opposite chiralities are found within each molecule,
but in only one PPh3 group (molecule 2, ligand 1) is
the symmetry at all a close approach to the usual three-
fold norm.
[Ru(p-cymene)Cl2]2. The reaction between
6 and
3.3. Reactivity of derivative [Cu(Qpy)(PPh3)2]
[Ru(p-cymene)Cl2]2 was performed in acetonitrile and,
after 24 h refluxing, AgPF6 was added to effect the chlo-
ride exchange, the ionic adduct 8 resulting (Scheme 3).
It is a brown solid with a sharp melting point. The
conductivity value of 136 Xꢀ1 cm2 molꢀ1 in acetonitrile
is typical of 1:1 ionic species [18]. In the IR spectrum
of 8 the strong bands at 840 and 695 cmꢀ1 are typical
of mas and ms of PF6, typical of ionic PF6 [20]. m(C@O)
Because the Q ligands of derivatives 4–6 contain
additional heterocyclic groups with different donor
atoms, we planned to investigate their potential as mul-
tidentate donors by exploring their reactivity toward Le-
wis acids. Attempted reactions between derivatives 4 or
5 with a Lewis acid such as Zn(BF4)2 Æ xH2O in acetoni-
PPh3
2+
PPh3
Cu
N
N
O
N
Me
F3C
Me
O
F3C
CF3
O
O
O
O
-
N
(BF4 )2
O
Me
N
+ Zn(BF4)2.xH2O
PPh3
PPh3
3
Zn
Cu
MeCN
CF3
Me
N
N
N
O
N
Ph3P
Ph3P
Cu
N
N
N
Cu
PPh3
PPh3
7
Scheme 2.

132
A. Cingolani et al. / Polyhedron 25 (2006) 124–133
+
Me
Me
O
Me
F3C
Me
Ru
AgPF6
N
-
O
O
CF3
Me
PF6
N
+ 1/2 [Ru(p-cymene)Cl2]2
PPh3
Cl
Cu
O
MeOH
PPh3
N
-AgCl
N
N
N
Cu
PPh3
PPh3
8
Scheme 3.
+
+
+
Me
Me
Me
Me
Me
Me
Me
Me
Me
Ru
Ru
Ru
-
-
O
NCCD3
O
O
CF3
Me
-
O
PF6
PF6
F3C
Me
PF6
Cl
Cl
Cl
O
O
CD3CN
CD3CN
CF3
N
N
N
N
N
N
N
Me
N
N
Cu
Cu
Cu
PPh3
PPh3
Ph3P
Ph3P
Ph3P
PPh3
Fig. 5. Species in equilibrium with each other (hypothesized from NMR spectra of CD3CN solution of derivative 8).
is shifted to lower frequency with respect to that found
in the IR of derivative 6, in accordance with the coordi-
nation of QCF3,py to the ruthenium through both car-
bonyl arms. In the far-IR region the bands due to
PPh3 [14] and to m(Ru-Cl) have been detected [21]. The
proton and carbon NMR spectra of 8 show three set
of resonances for both the {Ru(p-cymene)} and
{(QCF3,py)Cu(PPh3)2} fragments. This feature could be
explained by the presence of three different species in
equilibrium with each other, as suggested in Fig. 5.
The presence of two resonances in the 19F NMR spec-
trum at ꢀ73 and ꢀ76 ppm, the former due to CF3C@O
of a QCF3,py coordinated through C@O and the second
coincident with that found in the 19F NMR spectrum
of derivative 6, further supports our previous hypothesis.
Acknowledgement
Thanks are due to the University of Camerino (Italy)
and Carima Foundation for financial support.
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structure determinations of derivatives 1, 4, 5 and 6 have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC 268466–268468, 269315. Copies
of this information may be obtained free of charge from:
The Director, CCDC, 12 Union Road, Cambridge, CB2
1EZ, UK (fax: +44-1223-336-033; e-mail: deposit@ccdc.
cam.ac.uk or www: http://www.ccdc.cam. ac.uk).

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