Bis(2,3-diamino­pyridinium) phthalate dihydrate

Madhukar Hemamalini; Jia Hao Goh; Hoong-Kun Fun

doi:10.1107/S1600536811055838

. 2012 Jan 14;68(Pt 2):o402. doi: 10.1107/S1600536811055838

Bis(2,3-diaminopyridinium) phthalate dihydrate

Madhukar Hemamalini ^a, Jia Hao Goh ^a,^‡, Hoong-Kun Fun ^a,^*,^§

PMCID: PMC3275077 PMID: 22347022

Abstract

The complete anion of the title hydrated molecular salt, 2C₅H₈N₃ ⁺·C₈H₄O₄ ⁻·2H₂O, is generated by a crystallographic twofold axis. In the crystal, the cations, anions and water molecules are connected by N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional network. The crystal structure also features C—H⋯π interactions.

Related literature

For background to hydrogen-bonding patterns of 2-aminopyridine derivatives, see: Gellert & Hsu (1988 ▶); Banerjee & Murugavel (2004 ▶). For related structures, see: Hemamalini & Fun (2010a ▶,b ▶,c ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

2C₅H₈N₃ ⁺·C₈H₄O₄ ⁻·2H₂O
M _r = 420.43
Monoclinic,
a = 15.795 (5) Å
b = 13.083 (4) Å
c = 11.012 (4) Å
β = 115.194 (5)°
V = 2059.2 (11) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 100 K
0.42 × 0.36 × 0.03 mm

Data collection

Bruker APEXII DUO CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.958, T _max = 0.997
10343 measured reflections
2955 independent reflections
2148 reflections with I > 2σ(I)
R _int = 0.042

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.125
S = 1.04
2955 reflections
184 parameters
All H-atom parameters refined
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811055838/hb6574sup1.cif

e-68-0o402-sup1.cif^{(16.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811055838/hb6574Isup2.hkl

e-68-0o402-Isup2.hkl^{(142.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811055838/hb6574Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 and Cg2 are the centroids of the C6–C8/C6A–C8A and N1/C1–C5 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H5⋯O2ⁱ	0.90 (2)	2.03 (2)	2.9155 (19)	169.0 (18)
N1—H6⋯O2ⁱⁱ	0.98 (2)	1.790 (19)	2.7565 (18)	170.3 (19)
N2—H7⋯O1ⁱⁱ	0.92 (2)	1.99 (2)	2.8976 (19)	168.1 (19)
N3—H9⋯O1Wⁱⁱⁱ	0.89 (2)	2.09 (2)	2.978 (2)	179 (3)
N3—H10⋯O2ⁱ	0.89 (2)	2.23 (2)	3.078 (2)	158.8 (17)
O1W—H11⋯O1^iv	0.95 (3)	1.86 (3)	2.7878 (18)	165 (3)
O1W—H12⋯O1^v	0.92 (2)	1.99 (2)	2.8641 (18)	158.2 (19)
C3—H2⋯O1W^vi	0.984 (17)	2.516 (18)	3.369 (2)	145.0 (14)
C4—H8⋯Cg1ⁱⁱⁱ	1.01 (2)	2.76 (2)	3.629 (2)	144.3 (15)
C6—H3⋯Cg2^vii	0.959 (18)	2.568 (18)	3.497 (2)	163.4 (14)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .

Acknowledgments

MH, JHG and HKF thank the Malaysian Government and Universiti Sains Malaysia for the Research University grant No. 1001/PFIZIK/811160. MH also thanks Universiti Sains Malaysia for a post-doctoral research fellowship.

supplementary crystallographic information

Comment

2-Aminopyridine and its derivatives are amomg the most frequently used synthons in supramolecular chemistry based on hydrogen bonds (Gellert & Hsu, 1988; Banerjee & Murugavel, 2004). A series of similar complexes formed from 2-aminopyridine and carboxylates has been reported previously (Hemamalini & Fun, 2010a,b,c). The present work, 2,3-diaminopyridinium phthalate dihydrate, (2/1/1) (I), is a continuation of our structural study of complexes of the 2,3-diaminopyridinium system.

The asymmetric unit of the title compound, (I), contains one 2,3-diamino- pyridinium cation, a half of phthalate anion (which lies on a twofold axis; -x+1, y, -z+1/2) and a water molecule as shown in Fig. 1. The dihedral angle between the pyridine (N1/C1–C5) and benzene (C6–C8/ C6A–C8A) ring is 80.61 (7)°.

In the crystal structure (Fig. 2), the ion pairs and water molecules are connected via N—H···O, O—H···O and C—H···O (Table 1) hydrogen bonds forming a three-dimensional network. The crystal structure is further stabilized by C—H···π interactions involving the centroids of the C6–C8/C6A–C8A (Cg1) and N1/C1–C5 (Cg2) rings.

Experimental

A hot methanol solution (20 ml) of 2,3-diaminopyridine (27 mg, Aldrich) and phthalic acid (42 mg, Merck) were mixed and warmed over a magnetic stirrer hotplate for a few minutes. The resulting solution was allowed to cool slowly at room temperature and brown plates of the title compound appeared after a few days.