ABSTRACT In the title salt, C11H14N3O+·C7H5O3−, the phenyl ring of the cation is oriented at an angle of 67.0 (1)° with respect to the five-membered pyrazolone ring. The carboxylate plane of the anion is twisted out from the plane of the aromatic ring at an angle of 13.7 (3)°. In the crystal, the cations form hydrogen-bonded dimers with an R22(10) ring motif. The salicylate anion has an intramolecular O—H...O hydrogen bond.
A. Chitradevi,aS. Athimoolam,bB. Sridharcand S. Asath
aDepartment of Physics, Sri Subramanya College of Engineering & Technology,
Palani 624 615, India,bDepartment of Physics, University College of Engineering,
Anna University Tirunelveli, Nagercoil 629 004, India,cLaboratory of X-ray
Crystallography, Indian Institute of Chemical Technology, Hyderabad 500 007,
India, anddDepartment of Physics, Kalasalingam University, Krishnan Koil 626 190,
Correspondence e-mail: firstname.lastname@example.org
Received 29 October 2009; accepted 31 October 2009
Key indicators: single-crystal X-ray study; T = 293 K; mean ?(C–C) = 0.003 A ˚;
R factor = 0.041; wR factor = 0.113; data-to-parameter ratio = 12.9.
In the title salt, C11H14N3O+?C7H5O3?, the phenyl ring of the
cation is oriented at an angle of 67.0 (1)?with respect to the
five-membered pyrazolone ring. The carboxylate plane of the
anion is twisted out from the plane of the aromatic ring at an
angle of 13.7 (3)?. In the crystal, the cations form hydrogen-
bonded dimers with an R2
has an intramolecular O—H???O hydrogen bond.
2(10) ring motif. The salicylate anion
For the biological and pharmacological importance of pyra-
zolone derivatives and 4-aminoantipyrene compounds, see:
Filho et al. (1998); Jain et al. (2003); Mishra (1999); Sondhi et
al. (1999); Sondhi et al. (2001). For similar hydrogen-bonded
structures, see: Athimoolam & Natarajan (2006a,b,c); Athi-
moolam & Rajaram (2005). For hydrogen bonding inter-
actions and graph-set notations, see: Desiraju (1989); Etter et
al. (1990). For a description of the Cambridge Structural
Database, see: Allen (2002).
a = 8.3182 (6) A˚
b = 23.3006 (16) A˚
c = 8.8503 (6) A˚
? = 101.517 (1)?
V = 1680.8 (2) A˚3
Z = 4
Mo K? radiation
? = 0.10 mm?1
T = 293 K
0.24 ? 0.13 ? 0.12 mm
Bruker SMART APEX CCD area-
Absorption correction: none
16025 measured reflections
2959 independent reflections
2599 reflections with I > 2?(I)
R[F2> 2?(F2)] = 0.041
wR(F2) = 0.113
S = 1.05
H-atom parameters constrained
??max= 0.18 e A˚?3
??min= ?0.18 e A˚?3
Hydrogen-bond geometry (A˚,?).
Symmetry codes: (i) ?x þ 1;?y þ 1;?z þ 1; (ii) ?x þ 2;?y þ 1;?z þ 1.
Data collection: SMART (Bruker, 2001); cell refinement: SAINT
(Bruker, 2001); data reduction: SAINT; program(s) used to solve
structure: SHELXTL/PC (Sheldrick, 2008); program(s) used to
refine structure: SHELXTL/PC; molecular graphics: Mercury
(Macrae et al., 2006 ) and PLATON (Spek, 2009); software used to
prepare material for publication: SHELXTL/PC.
SAB sincerely thanks the Vice-Chancellor and Manage-
ment of Kalasalingam University, Anand Nagar, Krishnan
Koil, for their support and encouragement. SA thanks the
Vice-Chancellor of Anna University Tirunelveli for his
support and encouragement.
Supplementary data and figures for this paper are available from the
IUCr electronic archives (Reference: BT5124).
Allen, F. H. (2002). Acta Cryst. B58, 380–388.
Athimoolam, S. & Natarajan, S. (2006a). Acta Cryst. C62, o612–o617.
Athimoolam, S. & Natarajan, S. (2006b). Acta Cryst. E62, o4027–o4029.
Athimoolam, S. & Natarajan, S. (2006c). Acta Cryst. E62, o4219–o4221.
Athimoolam, S. & Rajaram, R. K. (2005). Acta Cryst. E61, o2764–o2767.
Bruker (2001). SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin,
Desiraju, G. R. (1989). Crystal Engineering: The Design of Organic Solids.
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Acta Cryst. (2009). E65, o3041–o3042doi:10.1107/S1600536809045760 Chitradevi et al.
Acta Crystallographica Section E
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Andrcopulo, A. D. & Yunes, R. A. (1998). Il Farmaco, 53, 55–58.
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Commun. 33, 563–577.
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R., van de Towler, M. & Streek, J. (2006). J. Appl. Cryst. 39, 453–457.
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R. & Dubey, M. P. (1999). Synthesis, pp. 878–884.
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Chitradevi et al.
Acta Cryst. (2009). E65, o3041–o3042
Acta Cryst. (2009). E65, o3041-o3042 [ doi:10.1107/S1600536809045760 ]
A. Chitradevi, S. Athimoolam, B. Sridhar and S. A. Bahadur
4-Aminoantipyrene, which contain pyrazolone ring, is an important compound in the class analgesic agent in otic solutions
in combination with other analgesic such as benzocaine and phenylephrine. Pyrazolone is a five-membered lactam ring
compound containing two N atoms and ketone in the same molecule. Lactam structure is an active nucleaus in pharmaco-
logical activity, especially in the class of nonsteroidal antiinflammatory agents used in the treatment of arthritis and other
musculo skeletal and joint disorders. Pyrazolone derivatives, as lactam structure related compounds, are also widely used in
preparing dyes and pigments. 4-aminoantipyrene and its derivatives have potential biological activities (Jain et al., 2003).
Analgesic and antiinflammatory activities of the 4-aminoantipyrene complexes were extensively studied and reported (Filho
et al., 1998; Sondhi et al., 1999). Apart from that, antimicrobial and anticancer activity of the 4-aminoantipyrine derivatives
and their metal complexes caught the attention of many researchers during last decade (Mishra, 1999; Sondhi et al., 2001).
As intra- and intermolecular hydrogen bonding interactions play a key role in bio-molecular interactions we are interested
on the structural elucidation of potentially bioactive compounds and their hydrogen bonding interactions in different en-
vironments. Thus, we are concerned with the biomolecular hydrogen bonding interactions through their X-ray analyses
of crystalline complexes involving drugs and vitamins with inorganic and organic acids (Athimoolam & Rajaram, 2005;
Athimoolam & Natarajan, 2006a-c).
Intermolecular forces also play very essential role in the formation of supramolecular organic systems. The phenomenon
of hydrogen bonding enlightens the area of molecular recognition, crystal-engineering research and organic synthons for
supramolecular research (Desiraju, 1989). Carboxylic acids and amines are two commonly used functional groups in crystal
engineering because they generally form robust architectures via O—H···O and N—H···O hydrogen-bonded interactions
(Etter et al., 1990). 4-aminoantipyrene is one of the such important ligands since it has potential sites for hydrogen bonding
interactions, viz., the amine N atom (as donor) and carbonyl O atom (as acceptor). Consideration of these above specifics
and to study the supramolecular geometry through hydrogen bonding extensions, the present investigation was undertaken.
4-aminoantipyrene was treated with salicylic acid and the title compound is crystallized.
The asymmetric unit of (I) consists of one single charged protonated 4-aminoantipyrene cation and a deprotonated sali-
cylate anion (Fig 1). Interatomic distances and angles are normal and in good agreement with the similar structures (Allen,
2002). The expected proton transfer from salicylic acid to 4-aminoantipyrene is established at N5 atom. The protonation on
the N site of the cation is evidenced from the elongated C—N bond distance and the deprotonation on anion is confirmed
from the COO- symmetric bond distances (Table 1). The phenyl ring of the cation is oriented with an angle of 67.0 (1)° to
the five membered pyrazolone ring. Also, in the asymmeric unit, the phenyl ring of the cation is making a dihedral angle
of 87.5 (1)° with the phenyl ring of the anion. The carboxylate plane of the salicylate anion is twisted from the plane of the
aromatic ring with an angle of 13.7 (3)°. The twisting of carboxylate plane can be associated with the hydrogen bonding
interactions of amino group of the cation. Due to the packing specificity of the crystal, one of the methyl atoms (C22) of the
cation is slightly out of plane of the five-membered pyrzalone ring with the distance of 0.542 (3) Å.
The most elegant aspect of the present work is found not only in the molecular structure but also in the crystal packing via
N—H···O and O—H···O hydrogen bonds. Fig. 2 shows the aggregation of the molecules around the inversion centres of the
unit cell through ring motifs. As a characterestic H-bond, salicylate anion consists a self associated intramolecular S(6) motif
through O—H···O hydrogen bond. The amino group of the cation is involved in two two-centered and one three-centered
hydrogen bonds. The amino and carbonyl O atom of the cation is involving in N—H···O hydrogen bond which leads to a
classical molecular dimerization through the ring R22(10) motif around the inversion center of the unit cell (Fig. 3). Other
two H atoms of amino group are involved in N—H···O hydrogen bonds with the adjascent salicylate anions. This leads to
another ring R42(8) motif formed through two cations and two anions (Fig. 4). This ring motif is further accompanied with
another adajascent ring R12(4) motif through the bifuracted (two-centered) hydrogen bond. These three intermolecular ring
motifs are intersected and extending along the a axis of the unit cell. This leads to hydrophilic region at the plane y=1/2
which are sanwitched between the hydrophobic regions at y=1/4 and 3/4.
The title compound was crystallized from the aqueous mixtures of 4-aminoantipyrene with salicylic acid, in the stochiometric
ratio of 1:1 at room temperature by the technique of slow evaporation.
All the H atoms were positioned geometrically and refined using a riding model, with C—H = 0.93 Å (aromatic) & 0.96 Å
(methyl), N—H = 0.86 Å and O—H=0.82 Å and Uiso(H) = 1.2–1.5 Ueq (parent atom).
Fig. 1. The molecular structure of the title compound with atom numbering scheme and 50%
probability displacement ellipsoids. H-bonds are shown as dashed lines.
Fig. 2. Packing diagram of the title compound viewed down the a-axis. H-bonds are shown as
Fig. 3. Inversion related ring R22(10) motif. Hydrogen atoms not involved in hydrogen bonds
(dashed lines) are omitted for clarity.
Fig. 4. Intermolecular ring R12(4) and R42(8) motifs and intramolecular S(6) motif. Hydrogen
atoms not involved in hydrogen bonds (dashed lines) are omitted for clarity.