Acridinium (6-carboxy­pyridine-2-carboxyl­ato)(pyridine-2,6-dicarboxyl­ato)zincate(II) penta­hydrate

Masoumeh Tabatabaee; Hossein Aghabozorg; Jafar Attar Gharamaleki; Mahboubeh A Sharif

doi:10.1107/S1600536809011106

. 2009 Mar 31;65(Pt 4):m473–m474. doi: 10.1107/S1600536809011106

Acridinium (6-carboxypyridine-2-carboxylato)(pyridine-2,6-dicarboxylato)zincate(II) pentahydrate

Masoumeh Tabatabaee ^a,^*, Hossein Aghabozorg ^b, Jafar Attar Gharamaleki ^b, Mahboubeh A Sharif ^c

PMCID: PMC2968778 PMID: 21582403

Abstract

The reaction of Zn(NO₃)₂ with pyridine-2,6-dicarboxylic acid (pydcH₂) and acridine (acr) in aqueous solution leads to the formation of the title compound, (C₁₃H₁₀N)[Zn(C₇H₃NO₄)(C₇H₄NO₄)]·5H₂O or (acrH)[Zn(pydcH)(pydc)]·5H₂O. In the title compound, the Zn^II atom is coordinated by four O atoms and two N atoms from the tridentate chelating rings of (pydc)²⁻ and (pydcH)⁻ anions. The geometry of the resulting ZnN₂O₄ coordination can be described as distorted octahedral. To balance the charges, one protonated acridine (acrH)⁺ cation is present. In the crystal structure, extensive O—H⋯O and N—H⋯O hydrogen bonds involving acrH⁺, the complex anion and uncoordinated water molecules form a three-dimensional network.

Related literature

For related structures, see: Aghabozorg et al. (2009 ▶); Moghimi et al. (2005 ▶); Ranjbar et al. (2002 ▶); Tabatabaee et al. (2008 ▶); Aghabozorg, Attar Gharamaleki et al. (2008 ▶); Aghabozorg, Firoozi et al. (2008 ▶); Aghabozorg, Manteghi et al. (2008 ▶); Safaei-Ghomi et al. (2009 ▶); Soleimannejad et al. (2008 ▶).

Experimental

Crystal data

(C₁₃H₁₀N)[Zn(C₇H₃NO₄)(C₇H₄NO₄)]·5H₂O
M _r = 666.89
Monoclinic,
a = 9.6083 (5) Å
b = 18.9681 (9) Å
c = 15.5435 (8) Å
β = 96.051 (1)°
V = 2817.0 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.95 mm⁻¹
T = 120 K
0.60 × 0.14 × 0.14 mm

Data collection

Bruker SMART 1000 CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1998 ▶) T _min = 0.652, T _max = 0.879
26948 measured reflections
7457 independent reflections
5795 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.108
S = 1.06
7457 reflections
445 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.87 e Å⁻³
Δρ_min = −0.35 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT-Plus (Bruker, 1998 ▶); data reduction: SAINT-Plus; 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.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809011106/bq2129sup1.cif

e-65-0m473-sup1.cif^{(28.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809011106/bq2129Isup2.hkl

e-65-0m473-Isup2.hkl^{(364.9KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Zn1—N2	2.0011 (16)
Zn1—N1	2.0238 (16)
Zn1—O3	2.0864 (14)
Zn1—O5	2.1443 (15)
Zn1—O7	2.2100 (14)
Zn1—O1	2.3406 (14)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2O⋯O3W	0.88 (4)	1.61 (4)	2.465 (2)	166 (4)
N3—H3N⋯O7	0.83 (3)	1.96 (3)	2.752 (2)	159 (3)
O1W—H1W1⋯O8	0.79 (3)	1.91 (3)	2.696 (2)	174 (3)
O1W—H2W1⋯O4ⁱ	0.85 (4)	2.07 (4)	2.901 (2)	165 (3)
O2W—H1W2⋯O4	0.82 (3)	2.07 (3)	2.873 (2)	166 (3)
O2W—H2W2⋯O5Wⁱⁱ	0.86 (3)	1.98 (3)	2.791 (3)	158 (3)
O3W—H1W3⋯O1Wⁱⁱⁱ	0.85 (4)	1.82 (4)	2.665 (2)	173 (3)
O3W—H2W3⋯O4W^iv	0.85 (4)	1.78 (4)	2.636 (2)	174 (5)
O4W—H1W4⋯O2Wⁱⁱⁱ	0.81 (4)	1.95 (4)	2.768 (3)	178 (3)
O4W—H2W4⋯O5	0.81 (3)	1.98 (3)	2.788 (2)	172 (4)
O5W—H1W5⋯O6^v	0.80 (3)	2.08 (3)	2.880 (2)	173 (3)
O5W—H2W5⋯O6	0.86 (4)	1.99 (5)	2.838 (2)	171 (4)

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

Acknowledgments

The authors express their appreciation to the Islamic Azad University, Yazd Branch, for financial support of this work.

supplementary crystallographic information

Comment

In the recent years, our research group has been interested in the synthesis of proton transfer compounds and study of their behavior with metal ions. We have focused on the proton delivery from polycarboxylic acids, which are considered as very good donors and amines as acceptors. Among polycarboxylic acids, pyridine-2,6-dicarboxylic acid (pydcH₂) as a very important carboxylate derivative has attracted much interest in coordination chemistry and it is the one that we utilized widely in our studies (Aghabozorg, Attar Gharamaleki et al., 2008; Aghabozorg, Firoozi et al., 2008; Aghabozorg, Manteghi et al., 2008; Tabatabaee et al., 2008; Soleimannejad et al., 2008; Aghabozorg et al., 2009; Safaei-Ghomi et al., 2009). In order to develop novel systems, we wish to report the first complex of Zn^II with pyridine-2,6-dicarboxylic acid as proton donor and acridine as proton acceptor.

The title compound consists of [Zn(pydcH)(pydc)]^- anion, (acrH)⁺ cation and five uncoordinated water molecules (Fig. 1). Zn^II ionic complex includes dianionic ((pydc)^2-) and monoanionic ((pydcH)^–) forms of pydcH₂, simultaneously. Zn^II atom is six-coordinated by these anions and the geometry of the resulting ZnN2O4 coordination can be described as distorted octahedral (Table 1). The N atoms occupy the axial positions. The N1—Zn1—N2 angle (167.38 (8)°) deviates from linearity. The dihedral angle between the mean planes of the pyridine rings (A1 and A2, defined in Fig. 1) is 88.16 (9)° indicating that (pydc)^2– and (pydcH)^– fragments are almost perpendicular to each other. Zn—N distances of (2.0011 (16)Å and 2.0238 (16)Å and Zn—O distances (Zn1—O1:2.0864 (14)Å, Zn1—O5: 2.1443 (15)Å, Zn1—O3:2.2100 (14)Å and Zn1—O7: 2.3406 (14)Å) are consistent with those found in (pydaH)[Zn(pydcH)(pydc)].3H₂O (Ranjbar et al. 2002) and (creatH)[Zn(pydcH)(pydc)].4H₂O (Moghimi et al. 2005). There are some hydrogen bonding interactions such as O–H···O and N–H···O between cations, anions and uncoordinated water molecules (Table 2). The water molecules act also as bridging agents and link anions together via hydrogen bonds (Fig. 2). As it is seen in Fig. 3, there are also π-π stacking interactions between the aromatic rings of the coordinated (pydc)^2– and (pydcH)^- anions and acridinum cation, with distances of 3.537 (1)Å for Cg5···Cg7 [Cg5: N1/C1—C5, Cg7:N3/C15—C20—C21—C22—C27] and 3.751 (1)Å for Cg6···Cg7 (Cg6:N2/C8—C12). Ion pairing, hydrogen bonding, π–π stacking and van der Waals interactions are also effective packing for the crystal structure. These interactions lead to formation of a three-dimensional supramolecular structure.

Experimental

An aqueous solution of zinc nitrate (Zn(NO₃)₂. 6H₂O, (0.15 g, 0.5 mmol) in water (20 ml) was added to a stirring solution of (20 ml) pyridine-2,6-dicarboxylic acid (0.1 g, 0.5 mmol) and 0.25 g (1.5 mmol) acridine. The reaction mixture was stirred at 25°C for 2 h. Colorless crystals of the title compound were obtained after two weeks at room temperature.