organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
The asymmetric units of (I) and (II) contain one acid anion
and one neutral acid molecule linked by hydrogen bonds to
the N2H5+ cation (Figs. 1 and 2). After transferring its proton
to hydrazine, the deprotonated carboxylate group shows
ISSN 0108-2701
The acid adducts hydrazinium
2-hydroxybenzoate–2-hydroxy-
benzoic acid (1/1) and hydrazinium
3-hydroxy-2-naphthoate–3-hydroxy-
2-naphthoic acid (1/1)
N. Arunadevi,a S. Devipriyab and S. Vairamb*
aDepartment of Chemistry, SNS College of Technology, Coimbatore 641 035, India,
and bDepartment of Chemistry, Government College of Technology, Coimbatore
641 013, India
Correspondence e-mail: vamshen@yahoo.com
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closely comparable bond lengths: C7—O1 = 1.2507 (13) A and
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C7—O2 = 1.2648 (12) A in (I), and C1—O1 = 1.2465 (14) A
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Received 25 September 2011
Accepted 19 December 2011
Online 6 January 2012
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and C1—O2 = 1.2635 (13) A in (II). The C2—C1—C7—O2
torsion angle in (I) is 19.03 (15)ꢂ, while the comparable torsion
angle in (II), viz. C11—C2—C1—O2, is 21.44 (15)ꢂ. Thus, the
The title molecular salts, N2H5 ꢀC7H5O3ꢁꢀC7H6O3 and N2H5 ꢀ-
C11H7O3ꢁꢀC11H8O3, are acid adducts containing a hydrazin-
ium cation, one molecule of a deprotonated acid and one
molecule of a neutral acid. The two compounds contain
essentially identical hydrogen-bond networks between the
hydrazinium cation and the acid molecules, which define
closely comparable two-dimensional layers in the structures.
The planes of the aromatic rings within both structures are
approximately parallel and the layers are stacked with
comparable intermolecular interactions.
+
+
Comment
Acid adducts comprise a combination of an acid and a salt of
that acid held together in a single crystal structure stabilized
by hydrogen bonds. Structurally characterized examples
include 8-hydroxyquinoline salicylate salicylic acid (Jebamony
& Thomas Muthiah, 1998), pyridinium 3,5-dinitrosalicylate
3,5-dinitrosalicylic acid (Smith et al., 2003) and tetra-n-butyl-
ammonium 2,6-dihydroxybenzoate 2,6-dihydroxybenzoic acid
(Almeida Paz et al., 2003). Hydrazine, a diacidic base, forms
many crystalline salts with carboxylic acids and their struc-
tures have been studied (Nilsson et al., 1968; Hady et al., 1969;
Thomas, 1973; Thomas & Liminga, 1978; Gajapathy et al.,
1983; Chevrier et al., 1987; Fun et al., 1995; Bhogala et al., 2005;
Starosta & Leciejewicz, 2008). Amongst hydroxy-substituted
aromatic acids, the formation of hydrazinium 2-hydroxy-
benzoate has been reported (Kuppusamy et al., 1995),
although its crystal structure has not been determined. In this
paper, we report the crystal structure of the acid adduct
hydrazinium 2-hydroxybenzoate–2-hydroxybenzoic acid (1/1),
(I), and the closely related adduct hydrazinium 3-hydroxy-2-
naphthoate–3-hydroxy-2-naphthoic acid (1/1), (II).
Figure 1
The asymmetric unit of adduct (I), showing 50% probablity displacement
ellipsoids. Thin dashed lines denote hydrogen bonds.
Figure 2
The asymmetric unit of adduct (II), showing 50% probablity displace-
ment ellipsoids. Thin dashed lines denote hydrogen bonds.
Acta Cryst. (2012). C68, o61–o64
doi:10.1107/S0108270111054722
# 2012 International Union of Crystallography o61
Arunadevi
