Preparation, separation and characterisation of two regioisomers of a N-hydroxyalkylpyridylpyrazole ligand: A structural investigation of their coordination to Pd(II), Pt(II) and Zn(II) centres

Article abstract of DOI:10.1016/j.ica.2010.11.041

The reaction of the β-diketone 1-phenyl-3-(pyridyn-2-yl)propane-1,3- dione, and the monosubstituted hydrazine 2-hydroxyethylhydrazine has been investigated. Two regioisomers were identified, 2-(3-phenyl-5-(pyridyn-2-yl)-1H- pyrazol-1-yl)ethanol (pzol.1) a

Full text of DOI:10.1016/j.ica.2010.11.041

Inorganica Chimica Acta 367 (2011) 35–43
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Inorganica Chimica Acta
journal homepage: www.elsevier.com/locate/ica
Preparation, separation and characterisation of two regioisomers
of a N-hydroxyalkylpyridylpyrazole ligand: A structural investigation of their
coordination to Pd(II), Pt(II) and Zn(II) centres
b
Carlos Luque a, Josefina Pons a, , Teresa Calvet , Mercè Font-Bardia b,c, Jordi García-Antón a, Josep Ros a
⇑
a Departament de Química, Unitat de Química Inorgànica, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
b Cristalꢀlografia, Mineralogia i Dipòsits Minerals, Universitat de Barcelona, Martí i Franquès s/n, 08028 Barcelona, Spain
c Unitat de Difracció de RX, Serveis Científico-Tècnics, Universitat de Barcelona, Solé i Sabarís 1-3, 08028 Barcelona, Spain
a r t i c l e i n f o
a b s t r a c t
Article history:
The reaction of the b-diketone 1-phenyl-3-(pyridyn-2-yl)propane-1,3-dione, and the monosubstituted
hydrazine 2-hydroxyethylhydrazine has been investigated. Two regioisomers were identified, 2-(3-
phenyl-5-(pyridyn-2-yl)-1H-pyrazol-1-yl)ethanol (pzol.1) and 2-(5-phenyl-3-(pyridyn-2-yl)-1H-pyra-
zol-1-yl)ethanol (pzol.2) in 57:43 ratio. The separation of the regioisomers was done by silica column
chromatography using ethyl acetate as eluent.
Received 19 September 2010
Received in revised form 19 November 2010
Accepted 23 November 2010
Available online 5 December 2010
Palladium(II) and platinum(II), [MCl2(pzol.1)2], [MCl2(pzol.2)], and zinc(II), [ZnCl2(pzol.1)],
[ZnCl2(pzol.2)] complexes were synthesised and characterised. The crystals and molecular structures of
[PdCl2(pzol.2)]ꢀH2O and [ZnCl2(pzol.2)] were solved by X-ray diffraction, and consist of mononuclear
complexes. In complex [PdCl2(pzol.2)]ꢀH2O, the Pd(II) centre has a typical square planar geometry, with
a slight tetrahedral distortion. The tetra-coordinated atom is bonded to one pyridinic nitrogen, one pyr-
azolic nitrogen and two chlorine atoms in cis disposition. The pzol.2 ligand acts as a bidentate chelate
forming a five-membered metallocycle ring. In complex [ZnCl2(pzol.2)], the Zn(II) is five-coordinated
with two Zn–N bonds (Zn–Npz and Zn–Npy), one Zn–OH bond and two Zn–Cl bonds. The coordination
geometry is intermediate between a trigonal bipyramid and a square pyramid. In this complex, the ligand
pzol.2 is tridentated and forms two metallocycle rings.
Keywords:
N-hydroxyalkylpyridylpyrazole ligands
Regioisomers
Palladium(II)
Platinum(II)
Zinc(II)
Crystal structures
Ó 2010 Elsevier B.V. All rights reserved.
1. Introduction
The pyrazole ring is present in many pharmacologically impor-
tant compounds. Although many methods are known for the con-
The coordination chemistry of the pyrazole-derived ligands has
been extensively studied in recent years [1]. In particular, the
chemistry of N-hydroxyalkylpyrazole and N-hydroxyalkyl-3,5-
dimethylpyrazole compounds has been studied by Driessen et al.
They have described the synthesis and characterisation of some
of these ligands with Ni(II), Cu(II), and Co(II) [2]. Moreover, the
[SnMe2Cl2(HL)] (HL = 1-hydroxymethylpyrazole) has also been
studied [3].
In our group, we have continued the study of the N-hydrox-
yalkylpyrazole and N-hydroxyalkyl-3,5-dimethylpyrazole ligands.
In particular, we have described the reaction of the ligands that
contain hydroxymethyl, hydroxyethyl or hydroxypropyl moieties
with Pd(II) and Pt(II), obtaining complexes with stoichiometry
[MCl2(L0)2]. In all these complexes, the ligand L0 acts as monoden-
tate via N-pyrazole [4].
struction of this ring system, the search for novel synthetic
methodology addressing the necessity for a particular regioisomer
is always desirable [5].
In recent years, we have developed general synthesis of 1,3,5-
substituted pyrazole derived ligands, and focussed the research
on the development of methods for regioselective synthesis [6].
In a recent paper, we presented the synthesis and characterisa-
tion of a new 1,3,5-substituted pyrazole derived ligand, containing
an alcohol functionality: namely, 2-(3-(pyridyn-2-yl)-5-trifluoro-
methyl-1H-pyrazol-1-yl)ethanol (L00) and its reactivity toward
Pd(II). These reactions yield cis-[PdCl2(L00)], [Pd(L00)2](BF4)2 and
[PdCl(L00)](BF4). In complexes cis-[PdCl2(L00)] and [Pd(L00)2](BF4)2,
the ligand L00 acts as bidentate via N-pyrazole and N-pyridine. How-
ever, for complex [PdCl(L00)](BF4), the ligand L00 acts as tridentate via
N-pyrazole, N-pyridine and the oxygen atom of the alcohol group
[7].
As an extension to these results, in the present paper we
describe the preparation, separation and characterisation of two
regioisomers of a 1,3,5-substituted pyrazole derived ligand,
⇑
Corresponding author. Fax: +34 93 581 31 01.
E-mail addresses: josefina.pons@uab.es, josefina.pons@uab.cat (J. Pons).
0020-1693/$ - see front matter Ó 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2010.11.041

36
C. Luque et al. / Inorganica Chimica Acta 367 (2011) 35–43
N
O
O
NH2NHCH2CH2OH
ZnCl2
ZnCl2
+
N
N
N
N
N
N
pzol.1
43 %
pzol.2
57 %
HO
OH
[MCl2(CH3CN)2]
M = Pd, Pt
[MCl2(CH3CN)2]
M = Pd, Pt
N
N
N
N
N N
Cl
M
OH
Cl
M
HO
Cl
Cl
M = Pd (2), Pt (4)
OH
N
N
N
M = Pd (1), Pt (3)
N
N
N
Zn
Cl
6
Cl
O
H
N
N
N
5
Zn
Cl
Cl
O
H
Scheme 1.
2-(3-phenyl-5-(pyridyn-2-yl)-1H-pyrazol-1-yl)ethanol
(pzol.1)
from the integration of the pyrazolic proton (43 pzol.1: 57 pzol.2)
(Scheme 1). Fig. 1 shows the 1H NMR spectra of the ethylenic and
pyrazolic hydrogens for the mixture of regioisomers (pzol.1 + p-
zol.2) and for each regioisomers after separation.
The assignment of each one of the regioisomers was confirmed
by NOESY experiments. The regioisomer pzol.1 presents NOE-
interactions between the protons of the hydroxyalkyl chain and
the pyridyl group. For pzol.2, no NOE-interactions between these
groups were observed.
and 2-(5-phenyl-3-(pyridyn-2-yl)-1H-pyrazol-1-yl)ethanol (pzol. 2)
(Scheme 1). It is important to note that ligand pzol.2 has been
previously reported by some of the authors of the present manu-
script. The reactivity of pzol.2 towards Pd(II) has also been previ-
ously assayed, yielding [PdCl2(pzol.2)]. This complex was used in
Heck reaction catalysis [8]. In the present manuscript, the reactiv-
ity of both pzol.1 and pzol.2 with [MCl2(CH3CN)2] (M = Pd(II),
Pt(II)) and ZnCl2 was studied.
Both regioisomers were characterised by elemental analysis,
infrared, 1H and 13C{1H} NMR spectroscopy, and electrospray mass
spectrometry (ESI(+)–MS). For the assignment of the 13C{1H} NMR
spectra, we have employed HSQC techniques. The 1H NMR spectra
display the ortho-pyridinic hydrogen (Scheme 1) at d = 8.72 ppm
(2J = 4.8 Hz) (pzol.1), and d = 8.64 ppm (2J = 4.5 Hz) (pzol.2) as dou-
blets. The pyrazolic hydrogen was observed at d = 6.87 ppm
(pzol.1), and 6.99 ppm (pzol.2). The 13C{1H} NMR spectra contained
the signals at d = 104.3 ppm (pzol.1), and 105.2 ppm (pzol.2),
attributable to the CH of the pyrazole [10]. In the mass spectra
(ESI(+)–MS) of pzol.1 and pzol.2 ligands, one signal is observed at
266 (100%), attributable to [L + Na]+ (L = pzol.1, pzol.2).
2. Results and discussion
2.1. Synthesis of the ligands
The 1-phenyl-3-(pyridyn-2-yl)propane-1,3-dione was prepared
by Claysen condensation of methyl-2-pyridinecarboxylate and
acetophenone, using NaOEt as base and dry toluene as solvent
[9]. Treatment of 1-phenyl-3-(pyridyn-2-yl)propane-1,3-dione
with 2-hydroxyethylhydrazine in ethanol at room temperature
produced two regioisomers, 2-(3-phenyl-5-(pyridyn-2-yl)-1H-
pyrazol-1-yl)ethanol (pzol.1) and 2-(5-phenyl-3-(pyridyn-2-yl)-
1H-pyrazol-1-yl)ethanol (pzol.2) in 93% yield. The separation of
the regioisomers was carried out by silica column chromatogra-
phy using ethyl acetate as eluent. The ratio of the regioisomers
has been calculated through 1H NMR experiments, especially
2.2. Synthesis and general characterisation of complexes
The reaction of the ligands (pzol.1, pzol.2) with [MCl2(CH3CN)2]
(M = Pd(II) [11] or Pt(II) [12]), in CH2Cl2 for Pd(II) complexes and in

C. Luque et al. / Inorganica Chimica Acta 367 (2011) 35–43
37
3b
3a
N
N
N
N
N
N
1a
1b
OH
2a
2b
H
O
2c
2b
2a
pzol.2
pzol.1
1c
1a
1b
mixture of regioisomers
7.0
6.8
6.6
6.4
6.2
6.0
5.8
5.6
(ppm)
5.4
5.2
5.0
4.8
4.6
4.4
4.2
4.0
Fig. 1. 1H NMR spectra of the methylenic and pyrazolic hydrogens for the mixture of regioisomers (pzol.1 + pzol.2) and for each regioisomers after separation.
acetonitrile for Pt(II) complexes, yields [MCl2(pzol.1)2] (M = Pd(II)
(1), Pt(II) (3)) and [MCl2(pzol.2)] (M = Pd(II) (2), Pt(II) (4)) com-
plexes. The isolated products do not depend on the stoichiometries
used in the synthesis of the complexes. In this way, reactions were
performed with 1M:1L or 1M:2L molar ratios and the same results
were obtained. The reaction of pzol.1 or pzol.2 ligands with ZnCl2,
in 1ZnCl2/1L ratio, in absolute ethanol and in the presence of tri-
ethyl orthoformate, (CH(OC2H5)3), for dehydration purposes, yields
[ZnCl2(L)] (L = pzol.1 (5), pzol.2 (6)) (Scheme 1).
Compounds 1–6 were characterised by elemental analyses,
mass spectrometry, conductivity measurements, IR, and 1D and
2D NMR spectroscopies. The NMR signals were assigned by refer-
ence to the literature [10] and from DEPT, COSY, HSQC, and NOESY
spectra.
concentrations used for these experiments all the compounds are
soluble in these solvents and we have not observed the substitu-
tion of any of the ligands by acetonitrile or DMSO.
The IR spectra of the complexes 1–6 in KBr pellets, display
absorptions of the N-hydroxyalkylpyridylpyrazole derived ligands.
For all complexes, the most characteristic bands are those attribut-
able to the alcohol, pyridyl, pyrazole and phenyl groups:
(3482–3283 cmꢁ1), [ (C@N)]py (1619–1597 cmꢁ1), [
(C@C),
@C),
(C@N)]pz (1569–1510 cmꢁ1), [d(C@C), d(C@N)]py,pz (1468–
1444 cmꢁ1), [d(C–H)oop py (783–763 cmꢁ1
and [d(C–H)oop pz
(712–694 cmꢁ1).
In the IR spectra for complexes 1, 2, 5 and 6, the band attribut-
able to
(O–H) appears between 3278 and 3238 cmꢁ1, and for com-
plexes 3 and 4, appears at 3482 and 3461 cmꢁ1, respectively. For
complexes 1–4, the band attributable to (O–H) appears as a broad
m
(O–H)
m
m
m
(C
m
]
)
]
m
For complexes 1 and 3, the elemental analyses agree with the
formula [MCl2(pzol.1)2] (M = Pd(II), Pt(II)), and for complexes 2,
4, 5 and 6, they agree with the formula [MCl2(L)] (M = Pd(II), Pt(II),
Zn(II), and L = pzol.1, pzol.2).
m
band. However, for complexes 5 and 6, it appears as a well-defined
band, probably due to the coordination of the –OH group to the Zn
atom.
The positive ionisation spectra (ESI(+)–MS), of complexes 1 and
3, give peaks with m/z values of 635 (100%) (1) and 724 (100%) (3),
attributable to [Mꢁ2ClꢁH]+. For complexes 2, 4, 5, and 6, peaks
with m/z values of 408 (100%) (2), 496 (100%) (4), and 364
(100%) (5 and 6) are obtained, attributable to [MꢁCl]+. Molecular
peaks of the cations are observed with the same isotope distribu-
tion as the theoretical ones.
The IR spectra of all compounds, between 600 and 100 cmꢁ1
,
were also recorded. The complexes 1 and 2 show the
bands at 440 and 397 cmꢁ1, respectively, and complexes 3 and 4
show the
(Pt–N) at 421 and 463 cmꢁ1, respectively [14]. Finally,
complexes 5 and 6 show defined bands corresponding to (Zn–O)
and
(Zn–N) at 422, 418 and 420, 413 cmꢁ1, respectively [15].
Moreover, complexes 1 and 3 display one band at 334 and
357 cmꢁ1, respectively, attributable to
m(Pd–N)
m
m
m
Conductivity values of 10ꢁ3 M samples, in acetonitrile, for com-
pounds 1, 2, 5, and 6, and in DMSO for compounds 3 and 4, are in
agreement with the presence of non-electrolyte compounds. The
reported values for 10ꢁ3 M solutions of non-electrolyte complexes
m(MꢁCl) (M = Pd(II), Pt(II)),
which are typical of compounds with a trans disposition of the
chlorine atoms around the metal. In contrast, the spectra of com-
plexes 2 and 4 display two bands at 327 and 302 cmꢁ1, and 348
are lower than 120
X
ꢁ1 cm2 molꢁ1 or 50
X
ꢁ1 cm2 molꢁ1, in aceto-
and 339 cmꢁ1, respectively, corresponding to
Pt(II)), which are typical of compounds with a cis disposition of
m
(MꢁCl) (M = Pd(II),
nitrile or DMSO, respectively [13]. We have carried out the conduc-
tivity measurements in acetonitrile or DMSO, because in the
the chlorine atoms around the metal [14]. Finally, the complexes

38
C. Luque et al. / Inorganica Chimica Acta 367 (2011) 35–43
5 and 6 show two well-defined bands corresponding to
m(Zn–Cl) at
(H2O), linked by hydrogen bonding (Fig. 2). The H2O molecules
are disordered.
302 and 281 cmꢁ1, and 323 and 302 cmꢁ1, respectively [16].
The 1H and 13C{1H} NMR spectra of the compounds 1–6 were
recorded in DMSO-d6, due to the low solubility of these complexes
in other deutered solvents. The 1H and 13C{1H} NMR spectra were
consistent with the proposed formulation and showed the coordi-
nation of the ligands (pzol.1 and pzol.2) to the metal atoms. In the
1H NMR spectra, characteristic bands for the orto-pyridinic hydro-
gens are observed between 9.03 and 8.62 ppm as doublets, with
1H–1H coupling constants values, between 5.6 and 5.8 Hz. The val-
ues of the field shift and coupling constants are of the same order
as those obtained for other complexes with N-alkylpyridylpyrazole
derived ligands [17], but display higher field shift than [PdCl2(L00)],
[Pd(L00)2](BF4)2 and [PdCl(L00)](BF4). (L00 = 2-(3-(pyridyn-2-yl)-5-tri-
fluoromethyl-1H-pyrazol-1-yl)ethanol, possibly due to the pres-
ence of the trifluoromethyl group, in these complexes [6].
Other observed bands are those attributable to Hpz, which ap-
pear between 7.42 and 7.25 ppm. The values are comparable to
those observed for other complexes that contain N-hydrox-
yalkylpyrazole and N-hydroxyalkylpyridylpyrazole ligands [4,6,
17]. It is important to remark that for complexes 1 and 3, in the
1H NMR spectra, the Hpz appears at 7.25 and 7.45 ppm, respec-
tively. These values show a large displacement compared to the
same signal for the free ligand (Hpz appears at 6.87 ppm). These
data seem to indicate that pzol.1 is coordinated to Pd(II) (complex
1) or Pt(II) (complex 3) through the pyrazolyl group, as shown in
Scheme 1.
The palladium centre presents a typical square planar geometry
(with a slight tetrahedral distortion) in which the largest deviation
from the mean coordination plane is 0.058(3) Å. This distortion is
higher than that found in [PdCl2(L00)] (L00 = 2-(3-(pyridyn-2-yl)-5-
trifluoromethyl-1H-pyrazol-1-yl)ethanol (0.006(3) Å) [7]. The me-
tal atom is coordinated to one pzol.2 ligand, via one pyrazole and
one pyridine nitrogens, and two chlorine atoms in cis disposition.
The pzol.2 behaves as a bidentate ligand forming a five membered
metallocycle.
The [PdCl2(Npz)(Npy)] core (containing terminal chlorine atoms
in a cis disposition) is found in eight complexes described in the lit-
erature [7,17a,19]. The Pd–Npy, Pd–Npz and Pd–Cl bond lengths are
in the range of bond distances found in the literature for similar
complexes [7,17a,19a]. Selected bond distances and angles for this
complex are gathered in Table 1.
The N1–Pd–N3 bite angle is 79.76(10)°. This angle is compara-
ble to those found in the structures for analogous complexes de-
scribed in the literature [7,17a,19a].
The ligand pzol.2 is not planar. The pyridyl and phenyl groups
are twisted with respect to the pyrazole ring. The py–pz dihedral
angle is 9.28(4)°, the ph–pz angle is 57.05(4)° and the py–ph angle
is 61.15(3)°. The py–pz dihedral angle is higher and the pz–ph and
py–ph dihedral angles are of the same order as those found for
other complexes described in the literature [7,17a,19a].
The hydroxyethyl group, which is bonded to the N2 atom,
moves away from the chelating plane giving a torsion angle N1–
N2–C15–C16 of ꢁ67.5(4)°. This value is lower than that found for
the [PdCl2(L00)] complex (88.8(4)°) [7].
The ethylene protons of the Npz–CH2–CH2–OH chains appear as
two triplets between 4.70 and 4.22 ppm and 3.85 and 3.78 ppm,
with 1H, 1H coupling constants between 6.7 and 6.5 Hz.
In complexes 1–4, the signal attributable to the proton of the
alcohol group (O–H) is not observed. However, in complexes 5
and 6, this signal appears as a triplet at 4.90 ppm (3J = 6.6 Hz)
and as a broad band at 5.14 ppm, respectively.
The cis-[PdCl2(pzol.2)] molecules are stacked in antiparallel
manner and they form layers parallel to the crystallographic plane
ac. Each molecule is connected to other two adjacent molecules
through hydrogen bonding between a Cl1 atom and the hydroxy-
ethyl oxygen O1 with a distance of 3.208(4) Å. The hydrogen bon-
dings form a 1D network parallel to the [0 1 0] direction (Fig. 3a).
The O1–H1 bond lengths have been geometrically fixed in refine-
ment (0.82 Å) and the contact parameters between O1–H1 and
Cl1 are H1ꢀ ꢀ ꢀCl1, 2.56 Å; O1ꢀ ꢀ ꢀCl1, 3.208 Å; O1–H1ꢀ ꢀ ꢀCl1, 138°,
symmetry code: 1 ꢁ x, ½ + y, ½ ꢁ z.
Additional 195Pt{1H} NMR experiments for complexes 3 and 4,
at 298 K, revealed only one band for each complex. For these com-
plexes, the signals appear at ꢁ2193 and ꢁ2185 ppm, respectively.
These values appear in the range described in the literature for
complexes with [PtCl2N2] core (ꢁ2279, ꢁ1198 ppm) [18]. These
data illustrate how sensitive the platinum chemical shift is to the
average ligand environment.
The lattice structure is also stabilised by
pꢀ ꢀ ꢀp stacking interac-
tions between the pyrazole ring and the pyridine ring of inversion
related molecules. The angle between the planes formed by the
pyrazole and pyridine rings in two different molecules is 9.28°
and the distance between centroids is 3.758(3) Å. These values
are in agreement with the interval found in the literature for this
kind of interaction [3.3–3.8 Å] [20] (Fig. 3b).
2.3. Crystal and molecular structure of cis-[PdCl2(pzol.2)]ꢀH2O (2)
The crystal and molecular structure of complex 2 consists of
discrete cis-[PdCl2(pzol.2)] molecules and solvent molecules
2.4. Crystal and molecular structure of [ZnCl2(pzol.2)](6)
The crystal structure consists of discrete [ZnCl2(pzol.2)] mole-
cules and solvent molecules (CH2Cl2), linked by hydrogen bondings
(Fig. 4).
The central Zn(II) atom is penta-coordinated and surrounded by
a N2Cl2O environment, adopting a distorted trigonal bipyramidal
geometry. The value of the trigonality index (s) is 0.56 [21], and
Table 1
Selected bond lengths (Å) and bond angles (°) for cis-[PdCl2(pzol.2)]ꢀH2O (2) with
estimated standard deviations (e.s.d.s) in parentheses.
Pd–N(1)
Pd–N(3)
N(3)–Pd–N(1)
N(1)–Pd–Cl(1)
N(3)–Pd–Cl(1)
2.070(3)
2.042(3)
79.76(10)
172.86(7)
93.20(8)
Pd–Cl(1)
Pd–Cl(2)
N(3)–Pd–Cl(2)
N(1)–Pd–Cl(2)
Cl(1)–Pd–Cl(2)
2.2892(17)
2.2921(12)
172.96(8)
98.85(8)
Fig. 2. ORTEP diagram of complex [PdCl2(pzol.2)]ꢀH2O (2) showing an atom
labelling scheme. 50% probability amplitude displacement ellipsoids are shown.
Hydrogen atoms are omitted for clarity.
88.28(4)

C. Luque et al. / Inorganica Chimica Acta 367 (2011) 35–43
39
Table 2
Selected bond lengths (Å) and bond angles (°) for [ZnCl2(pzol.2)] (6) with estimated
standard deviations (e.s.d.s) in parentheses.
Zn–N(2)
Zn–N(1)
2.0807(18)
2.186(2)
Zn–Cl(1)
Zn–O(1)
2.2081(11)
2.2110(19)
Zn–Cl(2)
2.2631(12)
75.95(8)
120.49(5)
97.58(6)
N(2)–Zn–N(1)
N(2)–Zn–Cl(1)
N(1)–Zn–Cl(1)
N(2)–Zn–Cl(2)
N(2)–Zn–O(1)
N(1)–Zn–O(1)
Cl(1)–Zn–O(1)
81.22(7)
157.10(7)
92.35(6)
116.05(5)
2.268(12) Å] and Zn–O [2.2113(19) Å] bond lengths can be re-
garded as normal compared with the distances found in the litera-
ture. For Zn–Npz, the literature describes values between 1.945 and
2.172 Å [24], for Zn–Npy between 2.030 and 2.227 Å [23a–c,25], for
Zn–Cl between 2.188 and 2.373 Å [23,24a–g,25b] and for Zn–O be-
tween 1.923 and 2.281 Å [23,26].
The ligand pzol.2 is not planar. The pyridyl and phenyl groups
are twisted with respect to the pyrazole ring. The py–pz dihedral
angle is 5.55(12)°, the ph–pz angle is 33.61(12)° and the py–ph an-
gle is 32.88(9)°.
The hydroxyethyl group, which is bonded to the N3 atom,
moves away from the chelating plane giving a torsion angle N2–
N3–C15–C16 of ꢁ20.8(3)°. This value is lower than that obtained
for [PdCl2(pzol.2)], probably due to the coordination of the OH
group to the metal.
Fig. 3. (a) View of hydrogen bonding in the crystal structure of [PdCl2(pzol.2)]ꢀH2O
(2) forming an infinite chain. (b) View in projection along the stacking axis for
complex (2). Hydrogen atoms are omitted for clarity.
The molecules [ZnCl2(pzol.2)] are stacked along the [1 0 0]
direction. In contrast to complex 2, in this case the inversion re-
lated molecules form dimers trough hydrogen bonding between
Cl2 atom and the hydroxyethyl oxygen O1 with a distance of
3.087(2) Å (Fig. 5a). The O–H bond lengths have been geometrically
fixed in refinement (0.82 Å) and the contact parameters between
O–H and Cl are Hꢀ ꢀ ꢀCl, 2.65 Å; Oꢀ ꢀ ꢀCl, 3.087(2) Å; O–Hꢀ ꢀ ꢀCl, 115°;
symmetry code: ꢁx, 1 ꢁ y, 1 ꢁ z.
Moreover,
pꢀ ꢀ ꢀp interactions are observed between pyridine–
pyridine and pyrazole–pyrazole (Fig. 5b) rings. The angles between
the planes formed by the pyridine and pyridine rings in two differ-
ent molecules is 1.80° and the distance between centroids is
3.832(2) Å. The angle between the planes formed by the pyrazole
and pyrazole rings in two different molecules is 10.79°, and the
distance between centroids is 3.846(2) Å. The angles and distances
are in agreement with the interval found in the literature for this
kind of interactions [3.3–3.8 Å] [20].
Fig. 4. ORTEP diagram of complex [ZnCl2(pzol.2)] (6) showing an atom labelling
scheme. 50% probability amplitude displacement ellipsoids are shown. Hydrogen
atoms are omitted for clarity.
3. Conclusion
In summary, we present the preparation, separation and char-
acterisation of two regioisomers of a N-hydroxyethylpyridylpyraz-
ole derived ligand (pzol.1, pzol.2).
the angle N1–Zn–O1 is 157.11(7)°. The equatorial plane is defined
by two chlorine atoms and N2pz and in the axial positions N1py and
O1(OH) atoms are present. The mean deviation of the zinc atom
from the equatorial plane is 0.023(3) Å. The pzol.2 ligand acts as
a tridentate chelate and forms two membered rings, a six-mem-
bered ring, with twisted-boat conformation, and a five-membered
ring with planar conformation, which share and edge (Zn–Npz).
In the molecules, the angles in the equatorial plane range are
between 116.05° and 123.42° and the axial O1–Zn–N1py subtends
an angle of 157.11(7)°. The Zn–N1py [2.186(2) Å] is longer than the
Zn–N2pz bonds [2.0809(18) Å]. Selected bond lengths and angles
are listed in Table 2. The [ZnCl2(N)2(O)] core, containing two termi-
nal chlorine atoms is present in 21 complexes described in the lit-
erature [22], but when the oxygen atom is one alcohol group, this
core is only present in four complexes [23]. For compound 6, the
Zn–Npz [2.0809(18) Å], Zn–Npy [2.186(2) Å], Zn–Cl [2.2081(11) Å,
The study of the coordination of the pzol.1 ligand with Pd(II)
and Pt(II) has revealed the formation of complexes [MCl2(pzol.1)2]
(M = Pd(II); Pt(II)), and the reaction of the pzol.2 ligand with Pd(II)
and Pt(II) yields cis-[MCl2(pzol.2)] complexes. In complexes
[MCl2(pzol.1)2], the ligand shows monodentate coordination
(Npz), and for cis-[MCl2(pzol.2)] complexes the ligand shows biden-
tate coordination (Npz,Npy). On the other hand, the reaction of the
pzol.1 and pzol.2 ligands with ZnCl2, yields complexes [ZnCl2(L)].
For L = pzol.1, the ligand acts as bidentate (Npz,OH) but for
L = pzol.2, the ligand acts as tridentate (Npz,Npy,OH).
Ligands pzol.1 and pzol.2 are potentially tridentate (Npy,Npz,OH),
but pzol.1 ligand can act as monodentate (Npz) or bidentate
(Npz,Npy) and pzol.2 ligand can act as bidentate (Npz,OH) or triden-
tate (Npz,Npy,OH). These differences depend of the metal: for Pd(II)
and Pt(II), the –OH group does not coordinate to the metal centre,

40
C. Luque et al. / Inorganica Chimica Acta 367 (2011) 35–43
Fig. 5. (a) View of hydrogen bonding in the crystal structure of [ZnCl2(pzol.2)] (6) forming dimmers. (b) View in projection along the stacking axis for complex (6). Hydrogen
atoms are omitted for clarity.
whereas for Zn(II) atom, the –OH group can coordinate to the metal
centre.
stirred at room temperature for 3 h. After removing the solvent un-
der vacuum, the product was extracted from the oily residuum
with H2O/CHCl3. The collected organic layers were dried with
anhydrous sulfate and remover under vacuum. Ligands were ob-
tained in 93% yield as oils with sufficient purity (1H NMR). The sep-
aration of regioisomers was done by silica column chromatography
using ethyl acetate as eluent.
4. Experimental section
4.1. General details
pzol.1: Yield: 43%. Anal. Calc. for C16H15N3O (265.3): C, 72.43; H,
5.70; N, 15.84. Found: C, 72.33; H, 5.64; N, 15.88%. MS(ESI+): m/z
(%) = 288 (100) [pzol.1 + Na]+; 266 (63) [pzol.1 + H]+. IR (NaCl/
Standard Schlenk techniques were employed throughout the
synthesis using a double manifold vacuum line with high purity
dry nitrogen. All reagents were commercial grade materials and
were used without further purification. All solvents were dried
and distilled by standard methods.
The elemental analyses (C, H, N) were carried out by the staff of
the Chemical Analyses Service of the Universitat Autònoma de Bar-
celona on a Carlo Erba CHNS EA-1108 instrument. Conductivity
measurements were performed at room temperature (r.t.) in
10ꢁ3 M in acetonitrile and DMSO solutions employing a Cyber-
Scan CON 500 (Euthech Instruments) conductimeter. Infrared
spectra were run on a Perkin–Elmer FT spectrophotometer series
2000 cmꢁ1 as NaCl disks, KBr pellets or polyethylene films in the
range 4000–100 cmꢁ1 under a nitrogen atmosphere.
cmꢁ1):
(C@C),
d (C@N)]ar 1451, d(C–H)ip1088, 1057 d(C–H)oop
m
m
(O–H) 3245,
(C@N)]ar 1590, 1567, [
m
(C–H)ar 3067,
m
(C–H)al 2954, 2857,
(C@N)]pz 1551, [d(C@C),
783, d(C–H)oop
[m
m
(C@C),
m
ar
694. 1H NMR (CDCl3 solution, 250 MHz, 298 K) d = 8.72 [d, 1H,
pz
3J 4.8 Hz, Horto py], 8.19–7.30 [m, 8H, Hpy, ph], 6.87 [s, 1H, CH(pz)],
4.71 [t, 2H, 3J 5.0 Hz, NCH2CH2OH], 4.19 [t, 2H, 3J 5.0 Hz,
NCH2CH2OH]. 13C{1H} NMR (CDCl3 solution, 63 MHz, 298 K)
d = 151.2 [Corto py], 149.2 [C-py], 148.7 [C-ph], 137.9, 133.4 [C-
Cpy, C-Cph], 129.4–123.4 [Cpy, Cph], 104.3 [CH(pz)], 63.2
[NpzCH2CH2OH], 53.2 [NpzCH2CH2OH].
pzol.2: Yield: 52%. Anal. Calc. for C16H15N3O (265.3): C, 72.43; H,
5.70; N, 15.84. Found: C, 72.22; H, 5.58; N, 15.78%. MS(ESI+): m/z
(%) = 288 (100) [pzol.2 + Na]+, 266 (7) [pzol.2 + H]+. IR (NaCl/
The 1H, 13C{1H} NMR, DEPT, COSY, HSQC and NOESY spectra
were recorded on an NMR-FT Brucker AC-250 MHz spectrometer
in CDCl3 and DMSO-d6 solutions, at room temperature. 1H{195Pt}
and 195Pt{1H} NMR spectra were recorded at 298 K in DMSO-d6
solutions, and 77.42 MHz on a DPX-360 MHz Bruker spectrometer
using aqueous solutions of [PtCl6]2ꢁ (0 ppm) as an external refer-
ence and delay times, 0.01 s.
All chemical shifts values (d) are given in ppm. Mass spectra
were obtained with an Esquire 3000 ion trap mass spectrometer
from Bruker Daltonics.
cmꢁ1):
m
m
(O–H) 3283,
(C@N)]ar 1595, 1567, [
(C@N)]ar 1476, 1465, d(C–H)ip 1072, 1049, d(C–H)oop ar 787 d(C–
700. 1H NMR (CDCl3 solution, 250 MHz, 298 K) d = 8.64
m
(C–H)ar 3063,
m
(C–H)al 2935, 2873,
[m
(C@C),
m(C@C),
m(C@N)]pz 1550, [d(C@C),
m
H)oop
pz
[d, 1H, 3J = 4.5 Hz, Horto py], 8.00–7.21 [m, 8H, Hpy, ph], 6.99 [s, 1H,
CH(pz)], 4.31 [t, 2H, 3J 5.0 Hz, N–CH2CH2–OH], 4.07 [t, 2H, 3J
5.0 Hz, NCH2CH2OH]. 13C{1H} NMR (CDCl3 solution, 63 MHz,
298 K) d = 152.1 [Corto py], 149.6 [C-py], 146.3 [C-ph], 136.7, 131.9
[CCpy, CCph], 129.1–120.4 [Cpy, Cph], 105.2 [CH(pz)], 62.1
[NpzCH2CH2OH], 51.6 [NpzCH2CH2OH].
Synthesis of 1-phenyl-3-pyridin-2-yl-propane-1,3-dione has
previously been reported in the literature [9]. Samples of
[MCl2(CH3CN)2] (M = Pd(II) [10], Pt(II) [12], were prepared and de-
scribed in the literature.
4.3. Synthesis of the complexes [PdCl2(pzol.1)2] (1) and [PdCl2(pzol.2)]
(2)
4.2. Synthesis of the ligands 2-(3-phenyl-5-(pyridyn-2-yl)-1H-pyrazol
-1-yl)ethanol (pzol.1) and 2-(5-phenyl-3-(pyridyn-2-yl)-1H-pyrazol-
1-yl)ethanol (pzol.2)
The appropriate ligand (0.27 mmol: pzol.1, 0.072 g; pzol.2,
0.072 g) dissolved in dry dichloromethane (10 ml) was added to
a solution of [PdCl2(CH3CN)2] (0.13 mmol, 0.035 g for 1 and
0.27 mmol, 0.070 g for 2) in dry dichloromethane (20 ml). The
solution resulting was stirred at room temperature for 48 h. The
solution was cooled down to 0 °C and diethyl ether (5 ml) was then
The 1-phenyl-3-(pyridyn-2-yl)propane-1,3-dione (6.60 mmol,
1.49 g) was dissolved in ethanol (25 ml). To this solution 2-
hydroxyethylhidrazine (6.60 mmol, 0.50 g) was added and the
mixture was stirred at 0 °C for 2 h. The resulting solution was

C. Luque et al. / Inorganica Chimica Acta 367 (2011) 35–43
41
added to induce precipitation. The yellow solution was filtered off,
washed twice 5 ml of diethyl ether and dried under vacuum.
1: Yield: 60%. Anal. Calc. for C32H30N6O2PdCl2 (707.9): C, 54.29;
H, 4.27; N, 11.87. Found: C, 53.95; H, 4.54; N, 11.62%. MS(ESI+): m/
250 MHz, 298 K) d = 9.39 [d, 1H, 3J = 5.6 Hz, Horto py], 8.31–7.59
[m, 8H, Hpy, ph], 7.50 [s, 1H, CH(pz)], 4.82 [t, 2H, 3J 4.5 Hz,
NCH2CH2OH], 3.83 [t, 2H, 3J 4.5 Hz, NCH2CH2OH]. 13C{1H} NMR
(DMSO-d6 solution, 63 MHz, 298 K) d = 149.1 [Corto py], 141.1 [C-
py], 129.7 [C-ph], 129.4, 128.7 [CCpy, CCph], 124.9–122.2 [Cpy,
Cph], 105.5 [CH(pz)], 60.3 [NpzCH2CH2OH], 51.2 [NpzCH2CH2OH].
195Pt{1H} (DMSO-d6 solution, 77 MHz, 298 K) d = ꢁ2185 (s).
z (%) = 635 (100) [PdCl2(pzol.1)2ꢁ2ClꢁH]+. Conductivity (
X
ꢁ1 cm2
m(O–H)
molꢁ1, 1.03 ꢂ 10ꢁ3 M in acetonitrile): 12.3. IR (KBr/cmꢁ1):
3261,
(C@C),
d(C–H)oop
m(C–H)ar 3061, m(C–H)al 2945, [m(C@C), m(C@N)]ar 1606,
[
m
m
(C@N)]pz 1510, [d(C@C),
m
(C@N)]ar 1459, d(C–H)ip 1065,
766, d(C–H)oop
696. (Polyethylene/cmꢁ1): (Pd–N)
ar
pz
4.5. Synthesis of the complexes [ZnCl2(pzol.1)] (5) and [ZnCl2(pzol.2)]
(6)
440,
m
(Pd–Cl) 334. 1H NMR (DMSO-d6 solution, 250 MHz, 298 K)
d = 8.69 [d, 1H, 3J 5.6 Hz, Horto py], 8.20–7.30 [m, 8H, Hpy, ph], 7.25
[s, 1H, CH(pz)], 4.69 [t, 2H, 3J 6.7 Hz, NCH2CH2OH], 3.78 [t, 2H, 3J
6.7 Hz, NCH2CH2OH]. 13C{1H} NMR (DMSO-d6 solution, 63 MHz,
298 K) d = 151.4 [Corto py], 149.0 [C-py], 148.1 [C-ph], 137.6, 133.4
[CCpy, CCph], 130.4–122.6 [Cpy, Cph], 104.5 [CH(pz)], 63.2
[NpzCH2CH2OH], 53.1 [NpzCH2CH2OH].
Zn(II) chloride (0.46 mmol, 0.062 g) was solved in 20 ml of
absolute ethanol and 4 ml of triethyl orthoformate (for dehidrata-
tion purposes). Then, 0.46 mmol of the corresponding ligand
(pzol.1, 0.122 g; pzol.2, 0.122 g) solved in absolute ethanol
(10 ml) and a white solution was obtained. Upon standing, in same
cases almost instantaneously crystalline materials started to pre-
cipitate. The solid product were isolated by filtration and dried un-
der vacuum.
2: Yield: 44%. Anal. Calc. for C16H15N3OPdCl2 (442.6): C, 43.42;
H, 3.42; N, 9.49. Found: C, 43.66; H, 3.52; N, 9.73%. MS(ESI+): m/z
(%) = 408 (100) [PdCl2(pzol.2)ꢁCl]+. Conductivity (
X
ꢁ1 cm2 molꢁ1
(O–H)
(C@N)]ar
(C@N)]ar 1458,
702. (Polyethylene/
pz
,
1.12 ꢂ 10ꢁ3
M m
in acetonitrile): 7.1. IR (KBr/cmꢁ1):
5: Yield: 45%. Anal. Calc. for C16H15N3OZnCl2 (401.6): C 47.85, H
3.76, N 10.46. Found: C, 48.00; H, 3.83; N, 10.27%. MS(ESI+): m/z
3278,
1608, 1551 [
m
(C–H)ar 3060,
m
(C–H)al 2866, 1608 [
(C@N)]pz 1551, [d(C@C),
d(C–H)ip 1068, d(C–H)oop 764, d(C–H)oop
m(C@C), m
m
m(C@C),
m
(%) = 364 (100) [ZnCl2(pzol.1)ꢁCl]+. Conductivity (
X
m
ꢁ1 cm2 molꢁ1
(O–H) 3238,
(C–H)ar 3061, m(C–H)al 2940, [m(C@C), m(C@N)]ar 1597, [m(C@C),
,
ar
1.23 ꢂ 10ꢁ3 M in acetonitrile): 9.7. IR (KBr/cmꢁ1):
cmꢁ1):
m
(Pd–N) 397, m
(Pd–Cl) 327, 302. 1H NMR (DMSO-d6 solu-
m
m
tion, 250 MHz, 298 K) d = 9.03 [d, 1H, 3J 5.6 Hz, Horto py], 8.30–
7.50 [m, 8H, Hpy, ph], 7.42 [s, 1H, CH(pz)], 4.27 [t, 2H, 3J 6.6 Hz,
NCH2CH2OH], 3.78 [t, 2H, 3J 6.6 Hz, NCH2CH2OH]. 13C{1H} NMR
(DMSO-d6 solution, 63 MHz, 298 K) d = 152.1 [Corto py], 149.4
[C-py], 146.5 [C-ph], 136.9, 132.3 [CCpy, CCph], 129.0–120.4 [Cpy,
Cph], 105.2 [CH(pz)], 62.4 [NpzCH2CH2OH], 52.0 [NpzCH2CH2OH].
(C@N)]pz 1569, [d(C@C),
m
(C@N)]ar 1464, d(C–H)ip 1032, d(C–
694. (Polyethylene/cmꢁ1):
(Zn–O),
(Zn–N), 422, 418, m
(Zn–Cl) 302, 281. 1H NMR (DMSO-d6 solution,
H)oop
766, d(C–H)oop
m
ar
pz
m
250 MHz, 298 K) d = 8.70 [d, 1H, 3J = 5.8 Hz, Horto py], 8.00–7.30 [m,
8H, Hpy, ph], 7.25 [s, 1H, CH(pz)], 4.90 [t, 1H, 3J 6.6 Hz, NCH2CH2OH],
4.70 [t, 2H, 3J 6.5 Hz, NCH2CH2OH], 3.78 [q, 2H, 3J 6.5 Hz,
NCH2CH2OH]. 13C{1H} NMR (DMSO-d6 solution, 63 MHz, 298 K) d
= 151.2 [Corto py], 149.1 [C-py], 148.3 [C-ph], 137.8, 132.0 [C-Cpy,
C-Cph], 130.1–121.8 [Cpy, Cph], 104.7 [CH(pz)], 63.3
[NpzCH2CH2OH], 53.2 [NpzCH2CH2OH].
4.4. Synthesis of the complexes [PtCl2(pzol.1)2] (3) and [PtCl2(pzol.2)]
(4)
The appropriate ligand (0.27 mmol: pzol.1, 0.072 g; pzol.2,
0.072 g) dissolved in dry acetonitrile (25 ml) was added to a solu-
tion of [PtCl2(CH3CN)2] (0.14 mmol, 0.047 g for 3 and 0.27 mmol,
0.094 g for 4) in dry acetonitrile (50 ml). The resulting solution
was stirred and refluxed for 24 h and concentrated on a vacuum
line to one fifth of the initial volume. The yellow solution was fil-
tered off, washed twice with 5 ml of diethyl ether and dried under
vacuum.
6: Yield: 46%. Anal. Calc. for C16H15N3OZnCl2 (401.6): C, 47.85; H,
3.76; N, 10.46. Found: C, 47.91; H, 3.82; N, 10.21%. MS(ESI+): m/z
(%) = 364 (100) [ZnCl2(pzol.2)ꢁCl]+. Conductivity (
X
m
ꢁ1 cm2 molꢁ1
(O–H) 3258,
(C–H)ar 3054, m(C–H)al 2942, [m(C@C), m(C@N)]ar 1608, [m(C@C),
,
1.27 ꢂ 10ꢁ3 M in acetonitrile): 10.4. IR (KBr/cmꢁ1):
m
m
(C@N)]pz 1549, [d(C@C),
m
(C@N)]ar 1461, d(C–H)ip 1049, d(C–H)oop ar
(Zn–O), (Zn–N)
m
(Zn–Cl) 323, 302. 1H NMR (DMSO-d6 solution, 250 MHz,
763, d(C–H)oop
698. mmax (Polyethylene/cmꢁ1):
m
m
pz
420, 413,
3: Yield: 58%. Anal. Calc. for C32H30N6O2PtCl2 (796.6): C, 48.25;
H, 3.80; N, 10.55. Found: C, 48.03; H, 3.58; N, 10.34%. MS(ESI+):
m/z (%) = 724 (100) [PtCl2(pzol.1)2ꢁ2ClꢁH]+. Conductivity
298 K) d = 8.62 [d, 1H, 3J 5.7 Hz, Horto py], 8.10–7.43 [m, 8H, Hpy, ph],
7.36 [s, 1H, CH(pz)], 5.14 [br, 1H, NCH2CH2OH], 4.22 [t, 2H, 3J 6.7 Hz,
NCH2CH2OH], 3.85 [m, 2H, NCH2CH2OH]. 13C{1H} NMR (DMSO-d6
solution, 63 MHz, 298 K) d = 152.3 [Corto py], 149.6 [C-py], 147.0
[C-ph], 137.1, 133.4 [CCpy, CCph], 129.3–120.2 [Cpy, Cph], 105.4
[CH(pz)], 62.2 [NpzCH2CH2OH], 51.9 [NpzCH2CH2OH].
(
m
m
X
ꢁ1 cm2 molꢁ1, 1.1 8 ꢂ10ꢁ3 M in DMSO): 19.4. IR (KBr/cmꢁ1):
(O–H) 3482,
(C@N)]ar 1615,
m
(C–H)ar 3087,
m(C–H)al 2907, 2861, [m(C@C),
[
m
(C@C),
m
(C@N)]pz 1520, [d(C@C),
m
(C@N)]ar
1468, 1452, d(C–H)ip 1078, d(C–H)oop
783, d(C–H)oop
712.
ar
pz
(Polyethylene/cmꢁ1): (Pt–Cl) 357. 1H NMR (DMSO-
m(Pt–N) 421, m
d6 solution, 250 MHz, 298 K) d = 9.52 [d, 1H, 3J = 5.8 Hz, Horto py],
8.38–7.62 [m, 8H, Hpy, ph], 7.45 [s, 1H, CH(pz)], 4.98 [t, 2H, 3J
4.9 Hz, NCH2CH2OH], 4.05 [t, 2H, 3J 4.9 Hz, NCH2CH2OH]. 13C{1H}
NMR (DMSO-d6 solution, 63 MHz, 298 K) d = 149.1 [Corto py],
147.4 [C-py], 138.3 [C-ph], 135.2, 131.7 [CCpy, CCph], 129.4–
125.2 [Cpy, Cph], 107.2 [CH(pz)], 62.4 [NpzCH2CH2OH], 54.2
[NpzCH2CH2OH]. 195Pt{1H} (DMSO-d6 solution, 77 MHz, 298 K)
d = ꢁ2193 (s).
4.6. X-ray crystal structures for compounds 2 and 6
Suitable crystals for X-ray diffraction of compounds [PdCl2(pzol.
2)] H2O (2) and [ZnCl2(pzol.2)] (6) were obtained through crystal-
lisation from a dichloromethane/diethyl ether (4:1) mixture.
For compounds 2 and 6 a prismatic crystal was selected and
mounted on a MAR 345 diffractometer with an image plate
detector. Unit-cell parameters were determined from 236 reflec-
tions for 2 and 319 reflections for 6 (3 < h < 31°) and refined by
least-squares method. Intensities were collected with graphite
4: Yield: 56%. Anal. Calc. for C16H15N3OPtCl2 (531.3): C, 36.17; H,
2.85; N, 7.91. Found: C, 36.09; H, 2.74; N, 7.81%. MS(ESI+): m/z
(%) = 496 (100) [PtCl2(pzol.2)ꢁCl]+. Conductivity (
X
ꢁ1 cm2 molꢁ1
(O–H) 3461, (C–
(C@C),
,
monochromatised Mo Ka radiation. For 2, 14 552 reflections were
measured in the range 2.60 6 h 6 32.43. 5696 of which were non-
equivalent by symmetry (Rint (on I) = 0.044). 4631 reflections were
0.95 ꢂ 10ꢁ4 M in DMSO): 27.2. IR (KBr/cmꢁ1):
m
m
H)ar 3092,
m
(C–H)al 2914, 2854, [
m
(C@C),
m(C@N)]ar 1619, [
m
m
(C@N)]pz 1522, [d(C@C),
m
(C@N)]ar 1464, 1444, d(C–H)ip 1083,
assumed as observed applying the condition I P 2r (I). For 6,
16 763 reflections were measured in the range 2.55 6 h 6 32.36,
5546 of which were non-equivalent by symmetry (Rint (on
d(C–H)oop
m
766, d(C–H)oop
700. mmax (Polyethylene/cmꢁ1):
ar
pz
(Pt–N) 463,
m
(Pt–Cl) 348, 339. 1H NMR (DMSO-d6 solution,

42
C. Luque et al. / Inorganica Chimica Acta 367 (2011) 35–43
Table 3
Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif. Supplementary data associated with this article
can be found, in the online version, at doi:10.1016/
j.ica.2010.11.041.
Crystallographic data for cis-[PdCl2(pzol.2)]H2O (2) and [ZnCl2(pzol.2)] (6).
2
6
Formula
M
C
16H17Cl2N3O2Pd
C17H17Cl4N3OZn
486.51
293(2)
monoclinic
P21/c
460.63
293(2)
monoclinic
P21/c
Temperature (K)
Crystal system
Space group
Unit cell dimensions
a (Å)
References
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l
F(0 0 0)
Crystal size
h range (°)
Index range
0.2 ꢂ 0.1 ꢂ 0.1
2.60–32.43
ꢁ19 < h < 21,
ꢁ11 < k < 12,
ꢁ24 < l < 23
14 552/5696
[R(int) = 0.0442]
99.3
0.1 ꢂ 0.09 ꢂ 0.08
2.55–32.36
ꢁ10 < h < 9,
ꢁ28 < k < 24,
ꢁ17 < l < 17
16 763/5546
[R(int) = 0.0651]
98.8
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Completeness to
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Absorption correction
Maximum and
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empirical
0.87 and 0.85
empirical
0.85 and 0.84
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Data/restraints/
parameters
5696/0/242
5546/14/244
Goodness-of-fit (GOF)
1.131
0.971
Final R1,
R1 (all data),
Residual electron
density (e Åꢁ3
x
R2
0.0460, 0.1287
0.0568, 0.1343
1.214 and ꢁ0.501
0.0376, 0.0965
0.0576, 0.1026
0.460 and ꢁ0.463
xR2
)
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For 2, the function minimised was
R
w||FO|2 ꢁ |FC|2|2, where
w = [r2 (I) + 0.0743P2 + 0.3221P]ꢁ1, and P = (|FO|2 + 2 |FC|2)/3. For
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R
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