(Acetonitrile) [2,6-bis(pyrazol-1-yl)-pyridine](isonicotinamide)copper(II)-tetrafluoroborate-ac etonitrile (1/2/2)

Article abstract of DOI:10.1107/S0108270102018097

The crystal structure of the compound [Cu(C₂H₃N)(C₁₁H₉N₅) (C₆H₆N₂O)](BF₄)₂ ·2C₂H₃N was discussed. It was found that the compound consists of cation which possessed distorted square-pyramidal geometries. The coordinated acetonitrile N-donor atom occupied the apical position. The analsis showed that the pairs of cations linked by N-H···F hydrogen bonds.

Full text of DOI:10.1107/S0108270102018097

metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
geometric parameter ꢀ [i.e. (171.42 156.94)/60] of 0.24 (ꢀ =
0.0 for C4v symmetry and ꢀ = 1.0 for D3h symmetry; Addison et
al., 1984). The conformation of the pyridine ring of the
isonicotinamide ligand is such that it makes a dihedral angle of
ISSN 0108-2701
(Acetonitrile)[2,6-bis(pyrazol-1-yl)-
pyridine](isonicotinamide)copper(II)±
tetrafluoroborate±acetonitrile (1/2/2)
Gerhard Baum,a Alexander J. Blake,b* Dieter Fenske,a
Peter Hubberstey,b Carine Juliob and Matthew A.
Withersbyb
47.8 (8)ꢀ with the pyridine ring of the tridentate ligand, which
is effectively planar, with dihedral angles between the pyra-
zole and pyridine rings of 1.3 (2) and 6.3 (2)ꢀ.
The cations form centrosymmetrically related pairs (Fig. 2)
linked through two tetra¯uoroborate anions by an R44(12)
hydrogen-bonding motif (Etter, 1990; Bernstein et al., 1995).
aInstitut fur Anorganische Chemie, Universitat Karlsruhe, Engesserstraûe, 76128
È
Karlsruhe, Germany, and bSchool of Chemistry, The University of Nottingham,
University Park, Nottingham NG7 2RD, England
Correspondence e-mail: a.j.blake@nottingham.ac.uk
Received 19 September 2002
Accepted 2 October 2002
Online 22 October 2002
Molecules of the title compound, [Cu(C2H3N)(C11H9N5)-
(C6H6N2O)](BF4)2Á2C2H3N, comprise (acetonitrile)[2,6-bis-
(pyrazol-1-yl)pyridine](isonicotinamide)copper(II) cations,
tetra¯uoroborate anions and lattice acetonitrile molecules.
The cations have distorted square-pyramidal geometries in
which the N3-donor, viz. 2,6-bis(pyrazol-1-yl)pyridine, and the
N-donor, viz. the isonicotinamide ligand, occupy the four
basal positions, with the coordinated acetonitrile N-donor
atom occupying the apical position. Pairs of cations are linked
by NÐHÁ Á ÁF hydrogen bonds through tetra¯uoroborate
anions, forming centrosymmetric dimers, which are further
linked by CÐHÁ Á ÁO hydrogen bonds into two-dimensional
undulating sheets, three of which interpenetrate to generate a
two-dimensional network.
Pertinent structural parameters of the hydrogen-bonded
contacts are collated in Table 2. The formation of this motif
[Scheme 1(a)] was unexpected, the simpler R22(8) motif [see
Comment
The title compound, (I), comprises an (acetonitrile)[2,6-
bis(pyrazol-1-yl)pyridine](isonicotinamide)copper(II) cation
(Fig. 1), two tetra¯uoroborate anions and two lattice aceto-
nitrile molecules. All four F atoms of both tetra¯uoroborate
anions are each disordered over two sites. The tridentate 2,6-
bis(pyrazol-1-yl)pyridine ligand occupies three of the four
basal positions of a distorted square-pyramidal CuN5 coordi-
nation sphere. The isonicotinamide ligand occupies the fourth
basal position and the coordinated acetonitrile molecule
occupies the apical position. Of the three ligating N atoms of
the tridentate ligand, the pyrazole N-donor atoms form much
Ê
longer CuÐN bonds [2.024 (3) and 2.026 (3) A] than the
Ê
pyridine N-donor atom [1.946 (2) A], which forms a CuÁ Á ÁN
contact similar to the isonicotinamide N-donor atom
II
[1.964 (2) A]. Typical of square-pyramidal Cu centres, the
Ê
Figure 1
apical acetonitrile-N atom is somewhat more distant
II
A view of the cation in (I), with the atom-numbering scheme.
Displacement ellipsoids are drawn at the 50% probability level and H
atoms are shown as spheres of arbitrary radii.
Ê
[2.316 (3) A]. The magnitude of the distortion of the Cu
coordination sphere (Fig. 1) can be quanti®ed by the
m542 # 2002 International Union of Crystallography
DOI: 10.1107/S0108270102018097
Acta Cryst. (2002). C58, m542±m544

metal-organic compounds
Experimental
The ligand 2,6-bis(pyrazol-1-yl)pyridine was synthesized by heating
at re¯ux for 72 h the mixture formed by adding 2,6-dichloropyridine
(4.12 g, 27.8 mmol) to a solution of sodium pyrazolate previously
prepared in tetrahydrofuran (100 ml) by reaction of pyrazole (3.80 g,
55.8 mmol) with excess NaH (60% dispersion in mineral oil; 2.80 g,
70 mmol). After cooling, the mixture was poured into iced water and
the resulting precipitate recovered by ®ltration (yield: 5.10 g,
23.7 mmol, 85%). For the preparation of the title compound, (I),
isonicotinamide (0.040 g, 0.33 mmol) was added to a mixture of
2,6-bis(pyrazol-1-yl)pyridine (0.068 g, 0.32 mmol) and hydrated
Cu(BF4)2ÁxH2O (0.100 g, 0.32 mmol) in acetonitrile (25 ml). After
stirring at ambient temperature for 24 h, the resulting green solution
afforded a small crop of green plate-like crystals.
Figure 2
A view of the centrosymmetric hydrogen-bonded dinuclear construction
generated by the NÐHÁ Á ÁF contacts of the hydrogen-bonded R44(12)
motif. Only one set of F atoms (F11A, F12A, F13A and F14A) is shown
for each tetra¯uoroborate anion. (Key: Cu atoms are large pale-grey
spheres, C are intermediate black spheres, N are intermediate dark-grey
spheres, O are intermediate pale-grey spheres, B are small pale-grey
spheres and F are intermediate black spheres.)
Crystal data
3
[Cu(C2H3N)(C11H9N5)(C6H6-
N2O)](BF4)2Á2C2H3N
Mr = 693.68
Dx = 1.560 Mg m
Mo Kꢂ radiation
Cell parameters from 12 955
re¯ections
Scheme 1(b)] based on the amide functionalities being
anticipated by analogy with the well known carboxylic acid-
based R22(8) supramolecular synthon [Scheme 1(c)] (Desiraju,
1995, 2000). Presumably, despite the greater strength of the
NÐHÁ Á ÁO C hydrogen bond compared with the NÐ
HÁ Á ÁFÐBF3 hydrogen bond, the energy release associated
with the formation of four of the latter is greater than that
associated with the formation of two of the former. Two CÐ
HÁ Á ÁO hydrogen bonds, in the form of an R12(7) motif, link the
dimers through the amide-O atom, generating an undulating
sheet structure parallel to the (001) plane (Table 2 and Fig. 3).
Orthorhombic, Pbca
Ê
a = 8.1790 (16) A
ꢃ = 2.5±25.5ꢀ
ꢁ = 0.83 mm
T = 193 (2) K
1
Ê
b = 22.747 (5) A
Ê
c = 31.752 (6) A
3
Ê
V = 5907 (2) A
Z = 8
Plate, green
0.32 Â 0.08 Â 0.02 mm
Data collection
Stoe IPDS diffractometer
Area detector scans
Absorption correction: multi-scan
(IPDS; Stoe & Cie, 1995)
Tmin = 0.84, Tmax = 0.95
4385 re¯ections with I > 2ꢄ(I)
Rint = 0.052
ꢃmax = 28.1ꢀ
Ê
The periodicity of the undulation (24.5 A) is such that the two-
h = 9 ! 9
dimensional network comprises three interpenetrating sheets
analogous to those observed in {[Co2(ꢁ-4,40-azopyridine)3-
(NO3)4]}n (Withersby et al., 1999, 2000).
k = 30 ! 25
19 461 measured re¯ections
6613 independent re¯ections
l = 42 ! 29
Intensity decay: none
Figure 3
A projection of the structure of (I) on to the (001) plane, showing the two-dimensional sheet structure generated by the CÐHÁ Á ÁO contacts of the
hydrogen-bonded R12(7) motif. The lattice acetonitrile molecules and tetra¯uoroborate anions have been omitted for clarity. Only one set of F atoms
(F11A, F12A, F13A and F14A) is shown for each tetra¯uoroborate anion (atom types are as depicted in Fig. 2).
ꢁ
Acta Cryst. (2002). C58, m542±m544
Gerhard Baum et al.
[Cu(C2H3N)(C11H9N5)(C6H6N2O)](BF4)2Á2C2H3N m543

metal-organic compounds
Table 1
Selected geometric parameters (A, ).
sponding occupancies around atom B2 converged to 0.60 (1) and
0.40 (1). Aromatic and amide H atoms, after location from ÁF
syntheses, were placed geometrically and re®ned with a riding model,
for which the CÐH and NÐH distances were constrained to be 0.95
Ê
and 0.88 A, respectively, and Uiso(H) = 1.2Ueq(C, N). Methyl H atoms
were located and treated similarly, with CÐH distances constrained
ꢀ
Ê
Cu1ÐN1
Cu1ÐN2
Cu1ÐN11
1.945 (3)
2.316 (3)
1.964 (3)
Cu1ÐN22
Cu1ÐN62
2.024 (3)
2.026 (3)
N1ÐCu1ÐN2
N1ÐCu1ÐN11
N1ÐCu1ÐN22
N1ÐCu1ÐN62
N2ÐCu1ÐN11
93.41 (12)
171.42 (13)
78.87 (12)
78.80 (11)
95.12 (12)
N2ÐCu1ÐN22
N2ÐCu1ÐN62
N11ÐCu1ÐN22
N11ÐCu1ÐN62
N22ÐCu1ÐN62
93.70 (14)
93.29 (14)
101.55 (12)
99.67 (12)
156.94 (11)
Ê
to be 0.98 A and Uiso(H) = 1.5Ueq(C)
Data collection: IPDS (Stoe & Cie, 1995); cell re®nement: IPDS;
data reduction: IPDS; program(s) used to solve structure: SIR92
(Altomare et al., 1994); program(s) used to re®ne structure:
SHELXL97 (Sheldrick, 1997); molecular graphics: CAMERON
(Watkin et al., 1996); software used to prepare material for publica-
tion: SHELXL97 and PLATON (Spek, 2002).
Table 2
Hydrogen-bonding geometry (A, ).
ꢀ
Ê
The authors thank the University of Nottingham for
®nancial support (to MAW).
DÐHÁ Á ÁA
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
N17ÐH17AÁ Á ÁF11Ai
N17ÐH17BÁ Á ÁF11Aii
N17ÐH17BÁ Á ÁF11Bii
N17ÐH17AÁ Á ÁF12Ai
N17ÐH17AÁ Á ÁF12Bi
C5ÐH5Á Á ÁO17iii
0.88
0.88
0.88
0.88
0.88
0.95
0.95
2.60
2.09
2.01
2.12
2.03
2.22
2.36
3.334 (6)
2.900 (6)
2.866 (7)
2.971 (5)
2.885 (7)
3.140 (5)
3.221 (4)
142
152
163
163
163
162
151
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: GG1141). Services for accessing these data are
described at the back of the journal.
C65ÐH65Á Á ÁO17iii
References
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R[F2 > 2ꢄ(F2)] = 0.059
wR(F2) = 0.175
S = 1.01
6613 re¯ections
401 parameters
H-atom parameters constrained
w = 1/[ꢄ2(Fo2) + (0.115P)2]
where P = (Fo2 + 2Fc2)/3
(Á/ꢄ)max = 0.002
3
Ê
Áꢅmax = 0.88 e A
3
È
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Ê
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The tetra¯uoroborate anions are affected by disorder; this was
modelled by allowing alternative positions for each F atom, with
extensive restraints applied to BÐF distances and FÐBÐF angles.
Around atom B1, the major and minor orientations re®ned to
occupancies of 0.57 (2) and 0.43 (2), respectively, while the corre-
ꢁ
m544 Gerhard Baum et al.
[Cu(C2H3N)(C11H9N5)(C6H6N2O)](BF4)2Á2C2H3N
Acta Cryst. (2002). C58, m542±m544