catena-Poly[(diaqua­strontium)-bis­(μ-2-methyl-3,5-dinitro­benzoato)]

Muhammad Danish; M Nawaz Tahir; Nazir Ahmad; Mehwish Nisa; Iram Saleem

doi:10.1107/S1600536811033769

. 2011 Aug 27;67(Pt 9):m1302. doi: 10.1107/S1600536811033769

catena-Poly[(diaquastrontium)-bis(μ-2-methyl-3,5-dinitrobenzoato)]

Muhammad Danish ^a, M Nawaz Tahir ^b,^*, Nazir Ahmad ^c, Mehwish Nisa ^c, Iram Saleem ^c

PMCID: PMC3200748 PMID: 22064938

Abstract

The title compound, [Sr(C₈H₅N₂O₆)₂(H₂O)₂]_n, essentially consists of a one-dimensional polymeric network with Sr₂O₂ rings extending along the [100] direction. The range of Sr—O bond lengths is 2.4822 (13)–2.8113 (13) Å. C—H⋯O and O—H⋯O hydrogen-bonding interactions stabilize the molecules in the form of a two-dimensional polymeric network parallel to (001). One of the nitro groups is disordered over three sets of sites with the occupancy ratio of 0.46:0.32:0.22.

Related literature

For background information and a related crystal structure, see: Danish, Ghafoor, Ahmad et al. (2011a ▶,b ▶); Danish, Ghafoor, Tahir et al. (2011 ▶); Danish, Tahir et al. (2011 ▶); Hundal et al. (2004 ▶).

Experimental

Crystal data

[Sr(C₈H₅N₂O₆)₂(H₂O)₂]
M _r = 573.93
Triclinic,
a = 8.0901 (3) Å
b = 11.2278 (4) Å
c = 12.1356 (4) Å
α = 93.805 (2)°
β = 104.566 (1)°
γ = 98.971 (1)°
V = 1047.40 (6) Å³
Z = 2
Mo Kα radiation
μ = 2.66 mm⁻¹
T = 296 K
0.30 × 0.26 × 0.22 mm

Data collection

Bruker KAPPA APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.457, T _max = 0.555
15464 measured reflections
3772 independent reflections
3510 reflections with I > 2σ(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.023
wR(F ²) = 0.057
S = 1.08
3772 reflections
324 parameters
6 restraints
H-atom parameters constrained
Δρ_max = 0.41 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); 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 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811033769/dn2710sup1.cif

e-67-m1302-sup1.cif^{(33.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811033769/dn2710Isup2.hkl

e-67-m1302-Isup2.hkl^{(181.1KB, hkl)}

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

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O13—H13A⋯O2ⁱ	0.84	1.99	2.808 (2)	164
O13—H13B⋯O12ⁱⁱ	0.84	2.42	3.238 (2)	163
O14—H14A⋯O4ⁱⁱⁱ	0.84	2.59	3.132 (2)	123
O14—H14B⋯O7^iv	0.84	1.96	2.800 (2)	173
O14—H14A⋯O10B^v	0.84	2.23	3.032 (8)	161
C15—H15⋯O6	0.93	2.42	3.258 (3)	150
C15—H15⋯O5ⁱⁱ	0.93	2.56	3.238 (3)	130

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

Acknowledgments

The authors acknowledge the provision of funds for the purchase of the diffractometer and encouragement by Dr Muhammad Akram Chaudhary, former Vice Chancellor, University of Sargodha, Pakistan.

supplementary crystallographic information

Comment

We have reported the synthesiz and crystal structures of Ag(I), Cu(II), trimethyltin(IV) and triphenyltin(IV) complexes of 2-methyl-3,5-dinitrobenzoic acid (Danish, Ghafoor, Ahmad et al., 2011a,b; Danish, Ghafoor, Tahir et al., 2011; Danish, Tahir et al., 2011). In continuation to synthesize other metal complexes of this ligand, the title compound (I), (Fig. 1) is being reported here.

In the title compound, the Sr⁺² cation is coordinated to eight O-atoms. Six O-atoms are of four carboxylate groups and two O-atoms from two water molecules. Each ligand of 2-methyl-3,5-dinitrobenzoic acid is chelated and bridged from a single O-atom to the Sr-atoms. In this way infinite one dimensional polymeric chains extend along the [100] direction via four membered planar Sr₂O₂ rings [Fig. 1]. The Sr—O bond lengths is in the range of [2.4822 (13)–2.8119 (13) Å] compared to [2.401 (7)–3.064 (7) Å] observed in the related crystal structure of bis(µ2–3,5-dinitrobenzoato)-bis(3,5-dinitrobenzoato)-bis(triethyleneglycol)-distrontium(ii) dihydrate (Hundal et al., 2004). The O—Sr—O bond angles are in the range of 47.88 (4)–157.98 (4)°. The distance between Sr to Sr atoms is 4.1786 (3) and 4.2224 (3) Å, whereas the distance between O-atoms in these four membered planes is 3.0888 (18) and 3.3135 (18) Å, respectively. The dihedral angle between two consective Sr₂O₂ planes is 85.02 (5)°.

There are two 2-methyl-3,5-dinitrobenzoato groups which differ from each other geometrically. In one ligand, the carboxylate A (O1/C1/O2), nitro groups B (O3/N1/O4) and C (O5/N2/O6) are oriented at dihedral angles of 45.95 (11)°, 13.97 (32)° and 31.65 (20)° with the benzene ring D (C2—C7) [r. m. s deviation of 0.0047 Å], respectively. In the other ligand one nitro group is disordered over three set of sites with occupancy ratio of 0.46:0.32:0.22. In this ligand, the carboxylate E (O7/C9/O8) is oriented at dihedral angles of 69.02 (09)° with the benzene ring F (C10—C15) [r. m. s deviation of 0.0052 Å], respectively. The dihedral angle between D/F is 28.95 (6)°.

The molecules are stabilized in the form of two-dimensional polymeric network along the plane (001) due to intra as well as inter-molecular H-bondings of C—H···O and O—H···O types (Table 1).

Experimental

Anhydrous strontium chloride (1.585 g, 0.01 mol) of was dissolved in 25 ml distilled water in 100 ml round bottom flask. Sodium salt of 3,5-dinitro-ortho-toluic acid (4.96 g, 0.02 mol) was dissolved in 15 ml of distilled water and added to the strontium chloride solution drop-wise. After complete addition, the reaction mixture was refluxed for 3 h. The reaction mixture was cooled to room temperature and given activated charcoal treatment and filtered. The filtrate was concentrated and kept for crystallization. Light brown prisms appeared within one week.

Decomposition point was 620 K.