Diaqua­bis[4-(dimethyl­amino)benzoato](isonicotinamide)zinc(II)

Tuncer Hökelek; Hakan Dal; Barış Tercan; Özgür Aybirdi; Hacali Necefoğlu

doi:10.1107/S1600536809017620

. 2009 May 14;65(Pt 6):m651–m652. doi: 10.1107/S1600536809017620

Diaquabis[4-(dimethylamino)benzoato](isonicotinamide)zinc(II)

Tuncer Hökelek ^a, Hakan Dal ^b, Barış Tercan ^c, Özgür Aybirdi ^d, Hacali Necefoğlu ^d,^*

PMCID: PMC2969605 PMID: 21583016

Abstract

The molecule of the title Zn^II complex, [Zn(C₉H₁₀NO₂)₂(C₆H₆N₂O)(H₂O)₂], contains two 4-(dimethylamino)benzoate (DMAB) ligands, one isonicotinamide (INA) ligand and two water molecules; one of the DMAB ions acts as a bidentate ligand while the other and INA are monodentate ligands. The four O atoms in the equatorial plane around the Zn atom form a distorted square-planar arrangement, while the distorted octahedral coordination is completed by the N atom of the INA ligand and the O atom of the water molecule in the axial positions. Intramolecular C—H⋯O hydrogen bonding results in the formation of a six-membered ring adopting an envelope conformation. The dihedral angle between the carboxyl groups and the adjacent benzene rings are 4.87 (16) and 2.2 (2)°, while the two benzene rings are oriented at a dihedral angle of 65.13 (8)°. The dihedral angle between the benzene and pyridine rings are 11.47 (7) and 74.83 (8)°, respectively. In the crystal structure, intermolecular O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds link the molecules into a supramolecular structure. π–π contacts between the pyridine and benzene rings and between the benzene rings [centroid–centroid distances = 3.695 (1) and 3.841 (1) Å, respectively] further stabilize the structure. Weak intermolecular C—H⋯π interactions are also present.

Related literature

For general backgroud, see: Antolini et al. (1982 ▶); Chen & Chen (2002 ▶); Amiraslanov et al. (1979 ▶); Bigoli et al. (1972 ▶); Hauptmann et al. (2000 ▶); Shnulin et al. (1981 ▶); Antsyshkina et al. (1980 ▶); Adiwidjaja et al. (1978 ▶); Catterick et al. (1974 ▶); Krishnamachari (1974 ▶). For related structures, see: Greenaway et al. (1984 ▶); Hökelek et al. (1995 ▶, 1997 ▶, 2007 ▶, 2008 ▶); Hökelek & Necefoğlu (1996 ▶, 1997 ▶, 2007 ▶).

Experimental

Crystal data

[Zn(C₉H₁₀NO₂)₂(C₆H₆N₂O)(H₂O)₂]
M _r = 551.91
Triclinic,
a = 6.8616 (2) Å
b = 8.0947 (3) Å
c = 22.4953 (4) Å
α = 90.683 (2)°
β = 92.838 (2)°
γ = 93.313 (3)°
V = 1245.69 (6) Å³
Z = 2
Mo Kα radiation
μ = 1.04 mm⁻¹
T = 100 K
0.57 × 0.27 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.720, T _max = 0.810
21315 measured reflections
6053 independent reflections
5647 reflections with I > 2σ(I)
R _int = 0.021

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.078
S = 1.29
6053 reflections
353 parameters
6 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.99 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809017620/xu2522sup1.cif

e-65-0m651-sup1.cif^{(25.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809017620/xu2522Isup2.hkl

e-65-0m651-Isup2.hkl^{(290.3KB, hkl)}

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

Table 1. Selected bond lengths (Å).

Zn1—O1	2.0353 (17)
Zn1—O3	2.1328 (17)
Zn1—O4	2.2584 (17)
Zn1—O6	2.1393 (17)
Zn1—O7	2.0647 (17)
Zn1—N1	2.1307 (19)

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H21⋯O4ⁱ	0.89 (3)	2.15 (3)	3.034 (3)	174 (3)
N2—H22⋯O3ⁱⁱ	0.89 (3)	1.95 (3)	2.820 (3)	164 (3)
O6—H61⋯O2	0.89 (3)	1.79 (3)	2.646 (2)	161 (3)
O6—H62⋯O5ⁱⁱⁱ	0.88 (3)	1.88 (3)	2.749 (2)	169 (3)
O7—H71⋯N3^iv	0.89 (3)	2.01 (3)	2.863 (3)	162 (3)
O7—H72⋯O2^v	0.87 (3)	1.80 (3)	2.667 (2)	171 (3)
C22—H22A⋯Cg3^vi	0.96	2.74	3.567 (3)	145
C23—H23C⋯Cg2^vii	0.96	2.86	3.644 (3)	140

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) . Cg2 and Cg3 are the centroids of the C9–C14 and N1/C15–C19 rings, respectively.

Acknowledgments

The authors are indebted to Anadolu University and Medicinal Plants and Medicine Research Centre of Anadolu University, Eskişehir, Turkey, for the use of X-ray diffractometer.

supplementary crystallographic information

Comment

Nicotinamide (NA) is one form of niacin. A deficiency of this vitamin leads to loss of copper from the body, known as pellagra disease. Victims of pellagra show unusually high serum and urinary copper levels (Krishnamachari, 1974). The nicotinic acid derivative N,N-Diethylnicotinamide (DENA) is an important respiratory stimulant (Bigoli et al., 1972). Transition metal complexes with biochemical molecules show interesting physical and/or chemical properties, through which they may find applications in biological systems (Antolini et al., 1982). Some benzoic acid derivatives, such as 4-aminobenzoic acid, have been extensively reported in coordination chemistry, as bifunctional organic ligands, due to the varieties of their coordination modes (Chen & Chen, 2002; Amiraslanov et al., 1979; Hauptmann et al., 2000).

The structure-function-coordination relationships of the arylcarboxylate ion in Zn^II complexes of benzoic acid derivatives may also change depending on the nature and position of the substituted groups on the benzene ring, the nature of the additional ligand molecule or solvent, and the pH and temperature of synthesis (Shnulin et al., 1981; Antsyshkina et al., 1980; Adiwidjaja et al., 1978). When pyridine and its derivatives are used instead of water molecules, the structure is completely different (Catterick et al., 1974).

The structure determination of the title compound, (I), a zinc complex with two 4-dimethylaminobenzoate (DMAB) and one isonicotinamide (INA) ligands and two water molecules, was undertaken in order to determine the properties of the ligands and also to compare the results obtained with those reported previously.

In the monomeric title complex, (I), the Zn atom is surrounded by two DMAB and INA ligands and two water molecules. One of the DMAB ions acts as a bidentate ligand, while the other and INA are monodentate ligands (Fig. 1). The four O atoms (O1, O3, O4 and O7 atoms) in the equatorial plane around the Zn atom form a highly distorted square-planar arrangement, while the distorted octahedral coordination is completed by the N atom of the INA ligand (N1) and the O atom of the water molecule (O6) in the axial positions (Table 1 and Fig. 1).

The near equality of the C1—O1 [1.265 (3) Å], C1—O2 [1.265 (3) Å], C8—O3 [1.278 (3) Å] and C8—O4 [1.271 (3) Å], bonds in the carboxylate group indicates a delocalized bonding arrangement, rather than localized single and double bonds, and may be compared with the corresponding distances: 1.256 (6) and 1.245 (6) Å in [Mn(DENA)₂(C₇H₄ClO₂)₂(H₂O)₂], (II) (Hökelek et al., 2008), 1.265 (6) and 1.275 (6) Å in [Mn(C₉H₁₀NO₂)₂(H₂O)₄]. 2(H₂O), (III) (Hökelek & Necefoğlu, 2007), 1.260 (4) and 1.252 (4) Å in [Zn(DENA)₂(C₇H₄FO₂)₂(H₂O)₂],(IV) (Hökelek et al., 2007), 1.259 (9) and 1.273 (9) Å in Cu₂(DENA)₂(C₆H₅COO)₄, (V) (Hökelek et al., 1995), 1.279 (4) and 1.246 (4) Å in [Zn₂(DENA)₂(C₇H₅O₃)₄]. 2H₂O, (VI) (Hökelek & Necefoğlu, 1996), 1.251 (6) and 1.254 (7) Å in [Co(DENA)₂(C₇H₅O₃)₂(H₂O)₂], (VII) (Hökelek & Necefoğlu, 1997) and 1.278 (3) and 1.246 (3) Å in [Cu(DENA)₂(C₇H₄NO₄)₂(H₂O)₂], (VIII) (Hökelek et al., 1997). In (I), the average Zn—O bond length is 2.1261 (17) Å and the Zn atom is displaced out of the least-squares planes of the carboxylate groups (O1/C1/O2) and (O3/C8/O4) by -0.531 (1) Å and 0.023 (3) Å, respectively. The dihedral angle between the planar carboxylate groups and the adjacent benzene rings A (C2—C7) and B (C9—C14) are 4.87 (16)° and 2.23 (21)°, respectively, while those between rings A, B and C (N1/C15—C19) are A/B = 65.13 (8), A/C = 11.47 (7) and B/C = 74.83 (8) °. Intramolecular C—H···O hydrogen bond (Table 2) results in the formation of a six-membered ring D (Zn1/O1/O2/O6/C1/H61) adopting envelope conformation, with atom Zn1 displaced by 0.610 (1) Å from the plane of the other ring atoms. In (I), the O3—Zn1—O4 angle is 60.03 (6)°. The corresponding O—M—O (where M is a metal) angles are 58.3 (3)° in (VI) and 55.2 (1)° in [Cu(Asp)₂(py)₂] (where Asp is acetylsalicylate and py is pyridine) [(IX); Greenaway et al., 1984].

In the crystal structure, strong intermolecular O—H···O, O—H···N and N—H···O hydrogen bonds (Table 2) link the molecules into a supramolecular structure, in which they may be effective in the stabilization of the structure. The π–π contacts between the pyridine and the benzene rings and the benzene rings, Cg1—Cg3ⁱ and Cg2···Cg2ⁱⁱ [symmetry codes: (i) x - 1, y, z, (ii) 1 - x, 1 - y, -z, where Cg1, Cg2 and Cg3 are centroids of the rings A (C2—C7), B (C9—C14) and C (N1/C15—C19), respectively] may further stabilize the structure, with centroid-centroid distances of 3.695 (1) and 3.841 (1) Å, respectively. There also exist two weak C—H···π interactions (Table 1).

Experimental

The title compound was prepared by the reaction of ZnSO₄.H₂O (0.90 g, 5 mmol) in H₂O (30 ml) and INA (1.22 g, 10 mmol) in H₂O (20 ml) with sodium p-dimethylaminobenzoate (1.88 g, 10 mmol) in H₂O (50 ml). The mixture was filtered and set aside to crystallize at ambient temperature for one week, giving colorless single crystals.