Clemizoledichlorocobalt(II)

Article abstract of DOI:10.1107/S0108270100005710

The structure of dichloro[1-(p-chlorobenzyl)-2-(1-pyrrolidinylmethyl-N)- 1,3-benzimidazole-N³]cobalt (II), [CoCl₂(C₁₉H₂₀ClN₃)], contains a molecule of clemizole bound in a bidentate manner to cobalt through its imidazole and pyrrolidinyl N atoms, with significantly different Co-N distances of 1.976 (5) and 2.126 (5) angstroms, respectively. The geometry around cobalt is distorted tetrahedral, with significantly different Co-Cl distances of 2.217 (2) and 2.233 (2) angstroms, and the pyrrolidinyl ring is disordered.

Full text of DOI:10.1107/S0108270100005710

metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
ISSN 0108-2701
Clemizoledichlorocobalt(II)
Masood Parvez* and Kristin Braitenbach
Department of Chemistry, The University of Calgary, 2500 University Drive NW,
Calgary, Alberta, Canada T2N 1N4
Correspondence e-mail: parvez@ucalgary.ca
Received 17 February 2000
Accepted 14 April 2000
The structure of dichloro[1-(p-chlorobenzyl)-2-(1-pyrrol-
idinylmethyl-N)-1,3-benzimidazole-N3]cobalt(II), [CoCl2(C19-
H20ClN3)], contains a molecule of clemizole bound in a
bidentate manner to cobalt through its imidazole and
pyrrolidinyl N atoms, with signi®cantly different CoÐN
Figure 1
ORTEPII (Johnson, 1976) drawing of (I) with displacement ellipsoids
plotted at the 50% probability level. The minor fraction of the disordered
pyrrolidinyl ring atoms are not shown.
Ê
distances of 1.976 (5) and 2.126 (5) A, respectively. The
geometry around cobalt is distorted tetrahedral, with signi®-
Ê
cantly different CoÐCl distances of 2.217 (2) and 2.233 (2) A,
and the pyrrolidinyl ring is disordered.
(4-thiazolyl)-1H-benzimidazole-N,N0]cobalt(II) monohydrate
(Umadevi et al., 1995), dichloro[phenylbis(2-pyridyl)phos-
phine-N,N0]cobalt(II) ethanol solvate (Ehrlich et al., 1984) and
bis(N-2-propylsalicylideneamino-N,O)cobalt(II) (Elerman et
al., 1996).
Comment
The molecular dimensions in the benzimidazole part of the
ligand are normal and the pyrrolidinyl ring is disordered. The
The crystal structures of clemizole hydrochloride (Parvez,
1996), clemizoledichlorozinc(II) (Parvez & Sabir, 1996a),
clemizole as a free base (Parvez & Sabir, 1996b), clemizole
tetrachlorocuprate(II) and clemizole tetrachlorocobaltate(II)
(Parvez & Sabir, 1997) have been reported from our labora-
tory. This H1 antihistamine has now been incorporated into a
cobalt complex to investigate further the effects such complex
formation may have on the conformation of the clemizole
moiety. In this paper, we report the structure of clemizoledi-
chlorocobalt(II), (I).
2
important bond distances are: Csp ÐCl = 1.747 (7) A and
Ê
mean Csp3ÐCsp2 = 1.51 (2), CÐCaromatic = 1.383 (11), NÐ
2
Csp = 1.390 (4) and NÐCsp = 1.482 (3) A, not including the
3
Ê
disordered pyrrolidinyl ring. It is interesting to note that the
Ê
N1ÐC7 bond [1.340 (7) A] is much shorter than expected for
Ê
a single bond and that the N2ÐC7 bond [1.337 (7) A] is much
longer than a double bond; these bonds must represent a
Ê
delocalized system with a mean NÐC distance of 1.339 (2) A;
the corresponding distances in the structure of clemizoledi-
chlorozinc(II) (Parvez & Sabir, 1996a) were 1.357 (5) and
Ê
1.321 (5) A, respectively. The pyrrolidinyl ring in (I) is disor-
dered over two sites with inequivalent site-occupancy factors
and its NÐC and CÐC distances were therefore constrained
Ê
at 1.48 (1) and 1.50 (1) A, respectively, during re®nement. The
separations between pairs of C atoms of the pyrrolidinyl ring
Ê
are in the range 0.47±0.77 A.
The benzimidazole and phenyl rings are essentially planar,
with the maximum deviations of atoms from the least-squares
Ê
planes being 0.013 (6) and 0.021 (4) A, respectively. The
In (I) (Fig. 1), clemizole is coordinated in a bidentate
manner to cobalt via imidazole and pyrrolidinyl N atoms with
signi®cantly different CoÐN distances of 1.976 (5) and
dihedral angle between these planes is 86.2 (2)ꢀ; the corre-
sponding angle in the structures of clemizoledichlorozinc,
clemizole hydrochloride, clemizole as a free base, clemizole
tetrachlorocuperate(II) and clemizole tetrachlorocobalt-
ate(II) are 81.1 (4) (Parvez & Sabir, 1996a), 82.8 (9) (Parvez,
1996), 68.8 (6) (Parvez & Sabir, 1996b), 70.5 (6) and 82.7 (9)ꢀ
(Parvez & Sabir, 1997), respectively. An examination of the
N1ÐC8ÐC9ÐC14 torsion angle in these complex molecules
shows that the orientation of the phenyl ring with respect to
Ê
2.126 (5) A, respectively. The Co atom is also bound to two Cl
Ê
atoms with CoÐCl distances of 2.217 (2) and 2.233 (2) A. The
geometry around cobalt is distorted tetrahedral. Similar
distances and geometry have been reported for a number of
closely related cobalt complexes, e.g. dichlorobis(2-methoxy-
pyridine)cobalt(II) (Allan et al., 1981), bis(1,3-benzothia-
zole)dichlorocobalt(II) (Oughtred et al., 1982), dichlorobis[2-
ꢁ
Acta Cryst. (2000). C56, 919±920
# 2000 International Union of Crystallography
Printed in Great Britain ± all rights reserved 919

metal-organic compounds
the imidazole ring in (I) [torsion angle 115.0 (16)ꢀ] is some-
what similar to the orientation of these rings in the free base
(torsion angle 125ꢀ) and clemizole tetrachlorocobaltate(II)
(torsion angle 116ꢀ); the rest of the structures have torsion
angles in the range of 133±153ꢀ. The major and minor
conformers of the disordered pyrrolidinyl ring have an N3-
Table 1
Selected geometric parameters (A, ).
ꢀ
Ê
Co1ÐN2
Co1ÐN3
Co1ÐCl3
Co1ÐCl2
Cl1ÐC12
N1ÐC7
1.976 (5)
2.126 (5)
2.217 (2)
2.233 (2)
1.747 (7)
1.340 (7)
1.394 (7)
1.479 (7)
N2ÐC7
N2ÐC6
1.337 (7)
1.386 (7)
1.482 (10)
1.485 (10)
1.484 (8)
1.489 (7)
1.503 (7)
N3ÐC190
N3ÐC160
N3ÐC15
N3ÐC19
N3ÐC16
Ê
envelope conformation with N3 0.62 (5) and 0.64 (5) A out of
N1ÐC1
N1ÐC8
the planes composed of the C16±C19 and C160±C190 atoms,
respectively; a similar conformation of the ®ve-membered ring
has been observed in the crystal structures mentioned above.
The structure of (I) is composed of independent complex
molecules separated by normal van der Waals distances and is
devoid of any intermolecular interactions. The imidazole
moieties of the molecules, which lie about inversion centers,
are stacked parallel to each other.
N2ÐCo1ÐN3
N2ÐCo1ÐCl3
N3ÐCo1ÐCl3
N2ÐCo1ÐCl2
N3ÐCo1ÐCl2
Cl3ÐCo1ÐCl2
C7ÐN1ÐC1
C7ÐN1ÐC8
C1ÐN1ÐC8
83.34 (18)
109.35 (16)
115.01 (15)
118.05 (16)
111.27 (15)
115.79 (8)
107.2 (5)
C7ÐN2ÐC6
105.6 (5)
114.7 (4)
139.7 (4)
114.5 (6)
109.5 (6)
101.7 (6)
108.9 (3)
115.0 (5)
106.7 (5)
C7ÐN2ÐCo1
C6ÐN2ÐCo1
C15ÐN3ÐC19
C15ÐN3ÐC16
C19ÐN3ÐC16
C15ÐN3ÐCo1
C19ÐN3ÐCo1
C16ÐN3ÐCo1
126.7 (5)
126.2 (5)
Experimental
The title compound was synthesized by adding 1.0 mmol of CoCl2Á-
6H2O to 2.0 mmol of clemizole hydrochloride in 20 ml of ethanol.
NH4OH was added until the pH was 8±9. The solution was evapo-
rated slowly at room temperature and blue prismatic crystals sepa-
rated after a few days.
isotropic displacement parameters of the H atoms were set equal to
1.2Ueq of the C atoms to which they were bonded.
Data collection: MSC/AFC Diffractometer Control Software
(Molecular Structure Corporation, 1988); cell re®nement: MSC/AFC
Diffractometer Control Software; data reduction: TEXSAN (Mole-
cular Structure Corporation, 1994); program(s) used to solve struc-
ture: SAPI91 (Fan, 1991); program(s) used to re®ne structure:
SHELXL97 (Sheldrick, 1997); molecular graphics: TEXSAN; soft-
ware used to prepare material for publication: SHELXL97.
Crystal data
3
[CoCl2(C19H20ClN3)]
Mr = 455.66
Monoclinic, P21=n
Dx = 1.516 Mg m
Mo Kꢁ radiation
Cell parameters from 25
re¯ections
Ê
a = 9.647 (6) A
ꢂ = 10±25ꢀ
ꢃ = 1.27 mm
T = 170 (2) K
Ê
b = 12.675 (6) A
1
Ê
c = 16.359 (5) A
ꢀ = 93.77 (4)ꢀ
V = 1996 (2) A
Z = 4
3
Ê
Prismatic, blue
0.40 Â 0.22 Â 0.16 mm
The authors thank the Natural Sciences and Engineering
Research Council, Canada, for providing the diffractometer
through an equipment grant to the University of Calgary.
Data collection
Rigaku AFC-6S diffractometer
!/2ꢂ scans
Absorption correction: empirical
scan (3 re¯ections; North et al.,
1968)
Tmin = 0.63, Tmax = 0.82
3754 measured re¯ections
3533 independent re¯ections
1425 re¯ections with I > 2ꢄ(I)
Rint = 0.097
max = 25ꢀ
ꢂ
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: FR1273). Services for accessing these data are
described at the back of the journal.
h = 0 ! 11
k = 0 ! 15
l = 19 ! 19
3 standard re¯ections
every 200 re¯ections
intensity decay: none
References
Allan, J. R., Jones, C. L. & Sawyer, L. (1981). J. Inorg. Nucl. Chem. 43, 2707±
2711.
Re®nement
Ehrlich, M. G., Fronczek, F. R., Watkins, S. F., Newkome, G. R. & Hager, D. C.
(1984). Acta Cryst. C40, 78±80.
Elerman, Y., Kabak, M. & Tahir, M. N. (1996). Acta Cryst. C52, 2434±2436.
Fan, H.-F. (1991). SAPI91. Rigaku Corporation, Tokyo, Japan.
Johnson, C. K. (1976). ORTEPII. Report ORNL-5138. Oak Ridge National
Laboratory, Tennessee, USA.
Molecular Structure Corporation (1988). MSC/AFC Diffractometer Control
Software. MSC, 3200 Research Forest Drive, The Woodlands, TX 77381,
USA.
Re®nement on F2
R[F2 > 2ꢄ(F2)] = 0.043
wR(F2) = 0.136
S = 0.979
3533 re¯ections
251 parameters
H-atom parameters constrained
w = 1/[ꢄ2(Fo2) + (0.0384P)2]
where P = (Fo2 + 2Fc2)/3
(Á/ꢄ)max < 0.001
3
Ê
Áꢅmax = 0.40 e A
3
Ê
0.44 e A
Áꢅmin
=
Molecular Structure Corporation (1994). TEXSAN. MSC, 3200 Research
Forest Drive, The Woodlands, TX 77381, USA.
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351±
359.
Oughtred, R. E., Raper, E. S., Nowell, I. W. & March, L. A. (1982). Acta Cryst.
B38, 2044±2046.
Parvez, M. (1996). Acta Cryst. C52, 904±905.
Parvez, M. & Sabir, A. P. (1996a). Acta Cryst. C52, 1651±1653.
Parvez, M. & Sabir, A. P. (1996b). Acta Cryst. C52, 1572±1574.
Parvez, M. & Sabir, A. P. (1997). Acta Cryst. C53, 675±677.
Sheldrick, G. M. (1997). SHELXL97. University of GoÈttingen, Germany.
Umadevi, B., Muthiah, P. T., Shui, X. & Eggleston, D. S. (1995). Inorg. Chim.
Acta, 234, 149±152.
The C atoms of the pyrrolidinyl ring were disordered with
inequivalent site-occupancy factors of 0.76 and 0.24 which were
established in the early re®nement cycles. In the ®nal rounds of
calculations, the site-occupancy factors of these C atoms were ®xed
and the atoms of the minor conformer were re®ned with isotropic
displacement parameters; the NÐC and CÐC distances in the
Ê
pyrrolidinyl ring were ®xed at 1.48 (1) and 1.50 (1) A, respectively,
using the command DFIX in SHELXL97 (Sheldrick, 1997). H atoms
were included in the re®nement at idealized positions with aromatic
Ê
and methylene CÐH distances of 0.95 and 0.99 A, respectively. The
ꢁ
920 Parvez and Braitenbach [CoCl2(C19H20ClN3)]
Acta Cryst. (2000). C56, 919±920