Acetato(N-phenyl-pyridine-2-carbox-amidato-k2 N,N)(N-phenyl-pyridine-2-carboxamide-k2 N 1,O)copper(II)

Article abstract of DOI:10.1107/S0108270107023414

The title complex, [Cu(C12H9N2O)(C2H3O2)(C12H10N2O)], is a neutral Cu ^II complex with a primary N3O2 coordination sphere. The Cu centre coordinates to both a deprotonated and a neutral mol-ecule of N-phenyl-pyridine-2-carboxamide and also to an

Full text of DOI:10.1107/S0108270107023414

metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
equatorial position and the ®fth coordination position being
occupied by a water molecule.
Communications
The N-phenylpyridine-2-carboxamide ligand (L) was
obtained by a condensation reaction between pyridine-
2-carboxylic acid and phenylamide in a basic reductive reac-
tion medium following a modi®cation of the procedure
described by Barnes et al. (1978) and a similar procedure
described by Ray et al. (1994). The ligand, potentially biden-
tate, reacted with copper(II) acetate forming a ®ve-coordinate
complex, (I). The synthesis of the complex was performed in a
fashion similar to that reported previously (Ray et al., 1994)
but using different reaction conditions. In the previous
synthesis, the ligand (dissolved in ethanol) was allowed to
react with an aqueous solution of CuSO4Á5H2O, while in the
synthesis reported here, the ligand was dissolved in methanol
and added to a methanol solution of Cu(CH3COO)2ÁH2O.
ISSN 0108-2701
Acetato(N-phenylpyridine-2-carbox-
amidato-j2N,N)(N-phenylpyridine-2-
carboxamide-j2N1,O)copper(II)
Ligia Gomes,a,c* John Nicolson Low, Mario A. D. C.
Valente,c Cristina Freirec and Baltazar Castroc
b
Â
a
Â
Â
CIAGEB±Faculdade de Ciencias de Saude, Escola Superior de Saude da UFP,
Universidade Fernando Pessoa, Rua Carlos da Maia 296, P-4200-150 Porto,
Portugal, bDepartment of Chemistry, University of Aberdeen, Meston Walk, Old
Aberdeen AB24 3UE, Scotland, and cREQUIMTE, Departamento de Quimica,
Ã
Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 4169-007
Porto, Portugal
Correspondence e-mail: lrgomes@ufp.pt
Received 19 April 2007
Accepted 12 May 2007
Online 14 June 2007
The title complex, [Cu(C12H9N2O)(C2H3O2)(C12H10N2O)], is
a neutral CuII complex with a primary N3O2 coordination
sphere. The Cu centre coordinates to both a deprotonated and
a neutral molecule of N-phenylpyridine-2-carboxamide and
also to an acetate anion. The coordination around the metal
centre is asymmetric, the deprotonated ligand providing two N
Ê
donor atoms [CuÐN = 1.995 (2) and 2.013 (2) A] and the
neutral ligand providing one N and one O donor atom to the
Ê
coordination environment [CuÐN = 2.042 (2) A and CuÐO =
Ê
2.2557 (19) A], the ®fth donor being an O atom of the acetate
Ê
ion [CuÐO = 1.9534 (19) A]. The remaining O atom from the
acetate ion can be considered as a weak donor atom [CuÐO =
Ê
2.789 (2) A], conferring to the Cu complex an asymmetric
octahedral geometry. The crystal structure is stabilized by
intermolecular NÐHÁ Á ÁO, CÐHÁ Á ÁO and CÐHÁ Á Áꢀ inter-
actions.
Comment
The title complex, (I), assumes a different geometry to pre-
viously reported cpmplexes in the literature with identical and
similar ligands. In the CuII complex with the same ligand (Ray
et al., 1994), the structure determination showed that the Cu
complex is four-coordinate with a symmetric N4 coordination
environment, with the ligand assuming a cis conformation. A
Cu complex with a similar ligand [N-(2-chloro-6-methyl-
phenyl)pyridine-2-carboxamide] has also been reported
(Patra et al., 1999). In this case, the molecular structure
determination showed that the Cu centre is ®ve-coordinate in
a distorted trigonal±bipyramidal geometry, having an N4O
coordination environment, with the pyridine and the amide N
atoms of each organic ligand occupying an axial and an
A view of the structure of the title complex and the coor-
dination environment around the Cu atom, together with the
atomic numbering scheme, is shown in Fig. 1. The coordination
environment around copper is of the N3O2-type and is
asymmetric. One of the N-phenylpyridine-2-carboxamide
molecules (ligand A) provides a pyridine N and an amide O
donor atom. The second molecule (ligand B, labelled X4#,
where X is the atom label and # is an integer) provides a
pyridine and a deprotonated amide N donor atom. The
remaining donor O atom, O3, is from the acetate anion. Atom
O31 of the acetate residue can be considered to interact
weakly with the CuII ion [Cu1ÐO31 = 2.789 (2) A]. In this
Ê
Acta Cryst. (2007). C63, m293±m296
DOI: 10.1107/S0108270107023414
# 2007 International Union of Crystallography m293

metal-organic compounds
case, the primary N3O2 ®ve-coordination geometry gives place
to an effective asymmetric octahedral elongated geometry
and ꢃ are the largest coordination angles; ꢁ = 0 for square-
pyramidal geometry and ꢁ = 1 for trigonal±bipyramidal
geometry (Addison et al., 1984)]. Ligand B (providing two N
donor atoms), an acetate O atom and the pyridine N atom of
ligand A encompass the basal plane of the square pyramid
Ï Â
(Kiani et al., 2002; Burcak et al., 2005). The primary Cu-atom
geometry is a distorted square-based pyramid with a ꢁ value of
0.10 [the structure index is de®ned as ꢁ = (ꢂ ꢃ)/60, where ꢂ
Ê
[amide Cu1ÐN47 = 1.995 (2) A, pyridine Cu1ÐN41 and
Ê
Cu1ÐN1 = 2.013 (5) and 2.042 (2) A, respectively, and acetate
Ê
Cu1ÐO3 = 1.9534 (19) A], from which the Cu atom is
Ê
displaced by 0.1253 (11) A towards an apical amide O donor
Ê
atom [Cu1ÐO2 = 2.2557 (19) A]. The apical Cu1ÐO2 bond
Ê
length is 0.26 A longer than the mean distance adopted by the
basal atoms. The bond angles involving the coordinated metal
centre and the donor atoms are given in Table 1. The largest
distortions from square-pyramidal geometry are indicated by
the N41ÐCu1ÐN1 and O3ÐCu1ÐN47 angles. These devia-
tions can be attributed to steric effects imposed by the
conformations assumed by the ligands.
The presence of the H atom on atom N27 in ligand A
precludes this atom being coordinated to the Cu atom; instead,
ligand A is rotated by approximately 180ꢀ and carbonyl atom
O2 is the donor to the Cu atom, so that ligands A and B
assume different conformations around the C2ÐC27 and
C42ÐC47 bonds, the N1ÐC2ÐC27ÐN27 torsion angle in
ligand A being 171.8 (2)ꢀ, and N41ÐC42ÐC47ÐN47, the
corresponding torsion angle in ligand B, being 0.1 (3)ꢀ. In
ligand A, the C27ÐN27ÐC21ÐC22 torsion angle is
174.7 (3)ꢀ, while the corresponding angle C47ÐN47Ð
Figure 1
A view of (I), with our numbering scheme. Displacement ellipsoids are
drawn at the 30% probability level.
Figure 2
A view of the chain parallel to the c axis formed by the action of one NÐ
HÁ Á ÁO hydrogen bond augmented by two CÐHÁ Á ÁO hydrogen bonds, all
involving atom O4 as the acceptor. Atoms labelled with an asterisk (*) or
a hash (#) are at the symmetry positions (1 x, 1 y, 12 + z) and (1 x,
1
have been omitted for the sake of clarity.
Figure 3
Aview of the chain parallel to the a axis formed by a CÐHÁ Á ÁO hydrogen
bond. Atoms labelled with an asterisk (*) or a hash (#) are at the
symmetry positions ( 1 + x, y, z) and (1 + x, y, z), respectively. H atoms
not involved in the hydrogen bonding have been omitted for the sake of
clarity.
y, 12 z), respectively. H atoms not involved in the hydrogen bonding
ꢁ
m294 Gomes et al. [Cu(C12H9N2O)(C2H3O2)(C12H10N2O)]
Acta Cryst. (2007). C63, m293±m296

metal-organic compounds
Crystal data
3
Ê
[Cu(C12H9N2O)(C2H3O2)-
(C12H10N2O)]
Mr = 518.02
V = 2427.7 (5) A
Z = 4
Mo Kꢃ radiation
1
Orthorhombic, Pna21
Ê
ꢅ = 0.94 mm
T = 120 (2) K
a = 7.9604 (1) A
Ê
b = 23.057 (3) A
0.25 Â 0.10 Â 0.10 mm
Ê
c = 13.227 (2) A
Data collection
Stoe Stadi-4 diffractometer
Absorption correction: multi-scan
(North et al., 1968)
Tmin = 0.799, Tmax = 0.912
6079 measured re¯ections
5831 independent re¯ections
4590 re¯ections with I > 2ꢄ(I)
Rint = 0.022
10 standard re¯ections
frequency: 120 min
intensity decay: none
Re®nement
R[F2 > 2ꢄ(F2)] = 0.035
wR(F2) = 0.088
S = 1.03
H-atom parameters constrained
3
Ê
Áꢆmax = 0.21 e A
3
Ê
0.26 e A
Figure 4
Áꢆmin
=
A stereoview of the chain formed by a CÐHÁ Á Áꢀ interaction. H atoms not
involved in the hydrogen bonding have been omitted for the sake of
clarity.
5831 re¯ections
317 parameters
1 restraint
Absolute structure: Flack (1983),
2827 Friedel pairs
Flack parameter: 0.003 (11)
C421ÐC422 in ligand B is 96.9 (3)ꢀ. The C27ÐN27 bond
Table 1
Selected bond and torsion angles (ꢀ).
Ê
[1.346 (3) A] is signi®cantly longer than the C47ÐN47 bond
Ê
[1.323 (3) A] at the 3ꢄ level. Atom H27 is thus available for
hydrogen bonding.
O3ÐCu1ÐN47
O3ÐCu1ÐN41
N47ÐCu1ÐN41
O3ÐCu1ÐN1
N47ÐCu1ÐN1
173.55 (9)
93.02 (9)
81.05 (9)
92.53 (9)
92.81 (9)
N41ÐCu1ÐN1
O3ÐCu1ÐO2
N47ÐCu1ÐO2
N41ÐCu1ÐO2
N1ÐCu1ÐO2
167.38 (8)
95.35 (7)
89.43 (8)
114.30 (8)
76.41 (8)
The supramolecular structure is de®ned by an NÐHÁ Á ÁO,
three CÐHÁ Á ÁO and one CÐHÁ Á Áꢀ hydrogen bond, which
combine to form a three-dimensional network. Atom N27 acts
as a hydrogen-bond donor, via H27, to O4i (all symmetry
codes are given in Table 2). This is augmented by the C3Ð
H3Á Á ÁO4i and C22ÐH22Á Á ÁO4i hydrogen bonds. These three
hydrogen bonds link the molecules into a chain that runs
parallel to the c axis (Table 2 and Fig. 2). Atom C5 acts as a
hydrogen-bond donor, via H5, to O3ii, thus linking the mol-
ecules into a chain that runs parallel to the a axis (Table 2 and
Fig. 3). Finally, atom C45 is involved in a CÐHÁ Á Áꢀ contact
with the pyridine ring containing atom N41iii (Table 2 and
Fig. 4).
N1ÐC2ÐC27ÐN27
C27ÐN27ÐC21ÐC22
171.8 (2)
174.7 (3)
N41ÐC42ÐC47ÐN47
C47ÐN47ÐC421ÐC422
0.1 (3)
96.9 (3)
Table 2
Hydrogen-bond geometry (A, ).
ꢀ
Ê
Cg5 is the centroid of the pyridine ring containing atom N41.
DÐHÁ Á ÁA
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
N27ÐH27Á Á ÁO4i
0.89
0.95
0.95
0.95
0.95
1.92
2.32
2.55
2.52
2.78
2.805 (3)
3.095 (4)
3.401 (4)
3.279 (4)
3.582 (3)
170
138
150
137
142
C3ÐH3Á Á ÁO4i
C5ÐH5Á Á ÁO3ii
C22ÐH22Á Á ÁO4i
C45ÐH45Á Á ÁCg5iii
Experimental
N-Phenylpyridine-2-carboxamide was prepared following a modi®-
cation of the procedure described by Barnes et al. (1978). A solution
consisting of a mixture of pyridine-2-carboxylic acid (picolinic acid,
40 mmol), phenylamide (aniline, 40 mmol) and triphenyl phosphite
(40 mmol) in 50 ml of pyridine was kept for 3 h in a boiling water
bath. The resulting solution was cooled and maintained at room
temperature for 48 h. The resulting white ®brous crystals were
®ltered off and washed with a small amount of a 1:1 mixture of
acetone and diethyl ether (78% yield). Analysis found: C 72.9, H 5.10,
N 14.01%; C12H10N2O requires: C 72.7, H 5.08, N 14.14%. For the
synthesis of (I), a solution of copper(II) acetate monohydrate in
methanol (2.5 mmol) was added to a solution of N-phenylpyridine-2-
carboxamide (5.0 mmol) in methanol at 323 K. The resulting solution
was left to cool for 24 h, allowing partial evaporation of the solvent.
Single crystals were obtained by slow evaporation of the resulting
solution at room temperature. These were collected and washed with
a 1:1 mixture of acetone and diethyl ether, and dried under low
pressure. Analysis found: C 60.23, H 4.45, N 10.78%; C26H22CuN4O4
requires: C 60.28, H 4.28, N 10.82%.
Symmetry codes: (i) x ‡ 1; y ‡ 1; z 12; (ii) x 1; y; z; (iii) x ‡ 21; y ‡ 12; z.
Compound (I) crystallized in the orthorhombic system; space
groups Pna21 and Pnma were permitted from the systematic
absences, and Pna21 was con®rmed by the analysis. H atoms were
treated as riding atoms, with CÐH distances of 0.95 (aromatic) and
Ê
Ê
0.98 A (methyl), an NÐH distance of 0.89 A, and Uiso(H) values of
1.5 (methyl) or 1.2 times Ueq(C,N). The correct orientation of the
structure with respect to the polar-axis direction was established by
means of the Flack (1983) parameter.
Data collection: STADI4 (Stoe & Cie, 1996); cell re®nement:
X-RED (Stoe & Cie, 1996); data reduction: X-RED; program(s) used
to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to
re®ne structure: OSCAIL (McArdle, 2003) and SHELXL97 (Shel-
drick, 1997); molecular graphics: PLATON (Spek, 2003); software
used to prepare material for publication: SHELXL97 and
PRPKAPPA (Ferguson, 1999).
ꢁ
Acta Cryst. (2007). C63, m293±m296
Gomes et al.
[Cu(C12H9N2O)(C2H3O2)(C12H10N2O)] m295

metal-organic compounds
Ï Â
Ï Ï Â
È
Burcak, M., Potocnak, I., Massa, W. & Jager, L. (2005). Acta Cryst. C61, m353±
È
X-ray data were collected at the Institut fur Anorganische
Chemie, Universitat Karlsruhe. LG thanks FundacËao Para a
Ã
Ciencia e Tecnologia (POCI/QUI/61873/2004) for ®nancial
support.
m355.
Ferguson, G. (1999). PRPKAPPA. University of Guelph, Canada.
Flack, H. D. (1983). Acta Cryst. A39, 876±881.
Kiani, S., Staples, R. J. & Packard, A. B. (2002). Acta Cryst. C58, m593±m595.
McArdle, P. (2003). OSCAIL for Windows. Version 10. Crystallography
Centre, Chemistry Department, NUI Galway, Ireland.
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351±
359.
È
Ä
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: GG3093). Services for accessing these data are
described at the back of the journal.
Patra, A. K., Ray, M. & Mukherjee, R. (1999). J. Chem. Soc. Dalton Trans.
pp. 2461±2466.
Ray, M., Mukherjee, R., Richardson, J. F., Mashuta, M. S. & Buchanan, R. M.
(1994). J. Chem. Soc. Dalton Trans. pp. 965±969.
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of
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ꢁ
m296 Gomes et al. [Cu(C12H9N2O)(C2H3O2)(C12H10N2O)]
Acta Cryst. (2007). C63, m293±m296