catena-Poly[[tetra­aqua­zinc(II)]-μ-2,2′-dihydr­oxy-5,5′-diazenediyldibenzoato]

In the title compound, [Zn(C₁₄H₈N₂O₆)(H₂O)₄]_n, the 2,2′-dihydr­oxy-5,5′-diazenediyldibenzoate ligand acts as a carboxyl­ate bridge, leading to the formation of a polymeric chain running along the [10] direction. The Zn^II atom is hexa-coordinated in a distorted octa­hedral geometry by six O atoms [Zn—O = 2.055 (4)–2.132 (3) Å] from two carboxylate ligands and four water mol­ecules. The crystal packing is stabilized by inter­molecular O—H...O, O—H...N and C—H...O hydrogen bonds, and two π–π inter­actions. The centroid–centroid distances are 3.803 (16) and 3.804 (17) Å.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.039
• wR factor = 0.098
• Data-to-parameter ratio = 11.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        Zn1
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.20
PLAT355_ALERT_3_C Long    O-H Bond (0.82A)   O2W    -   H2WA   ...       1.01 Ang.
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          8

Alert level G
PLAT804_ALERT_5_G ARU-Pack Problem in PLATON Analysis ............          1 Times

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Olsalazine, 2,2'-dihydroxy-5,5'-diazenediyldibenzoic acid, has been widely used to prevent and treat the inflammatory bowel diseases, such as ulcerative colitis (Klotz, 2005). In previous work, we have synthesized a serial of Zn (Tang, Tan, Chen & Cao, 2007), Cd and Co (Tang, Yang et al., 2007) complexes with phenanthroline as auxiliary ligand. We have also reported a Mn complex of olsalazine (Tang, Tan & Cao, 2007), but the zinc complex with single olsalazine as building block has not been reported yet. Here we reported the crystal structure of the title compound, (I), a new zinc complex of olsalazine.

In (I), the Zn atom is hexa-coordinated (Fig. 1) by two O atoms from two L ligands [H₂L=3,3-azo-bis(6-hydroxybenzoic acid)] and four water molecules in a distorted octahedral geometry (Table 1). Two ligands are cis to each other in an octahedral environment. Each ligand L acts as a carboxylate bridge, which leads to formation of a polymeric chain running in the direction [110]. Two neighbouring polymeric chains are paired by π···π interactions between the aromatic rings; the distances Cg1···Cg1ⁱ and Cg2···Cg2ⁱ are 3.803 (16) and 3.804 (17) Å, respectively [Cg1 and Cg2 are centroids of C2—C7 and C8—C13 rings, respectively; symmetry code: (i) x - 1, y - 1, z]. The crystal packing is further stabilized by the intermolecular O—H···O, O—H···N and C—H···O hydrogen bonds (Table 2).

Related literature

For related literature, see: Klotz (2005); Tang, Tan & Cao (2007); Tang, Tan, Chen & Cao (2007); Tang, Yang et al. (2007).

S2. Refinement

The hydroxy and C-bound H atoms were placed in calculated positions (C—H = 0.93 Å and O—H = 0.82 Å) and included in the refinement in the riding-model approximation, with U_iso(H) = 1.2U_eq(C,O). The water H atoms were located in a difference Fourier map and refined isotropically.

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2000); software used to prepare material for publication: SHELXTL (Bruker, 2000).

Figures

Fig. 1. A part of the polymeric structure of (I), showing displacement ellipsoids drawn at the 30% probability level and the atomic labelling. Unlabelled atoms are related to labelled atoms by the symmetry code (x - 1, y + 1, z).

catena-Poly[[tetraaquazinc(II)]- µ-2,2'-dihydroxy-5,5'-diazenediyldibenzoato]

Crystal data

[Zn(C14H8N2O6)(H2O)4]	F(000) = 896
Mr = 437.66	Dx = 1.752 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 935 reflections
a = 9.510 (2) Å	θ = 1.8–26.0°
b = 11.255 (3) Å	µ = 1.54 mm^−1
c = 16.214 (4) Å	T = 296 K
β = 107.019 (3)°	Block, orange
V = 1659.5 (7) Å^3	0.25 × 0.22 × 0.10 mm
Z = 4

Data collection

Bruker SMART APEX CCD area-detector diffractometer	3278 independent reflections
Radiation source: fine-focus sealed tube	3036 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
ϕ and ω scans	θmax = 26.0°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −11→11
Tmin = 0.699, Tmax = 0.861	k = −13→13
10784 measured reflections	l = −19→19

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.098	H atoms treated by a mixture of independent and constrained refinement
S = 1.10	w = 1/[σ^2(Fo^2) + (0.0307P)^2 + 1.3308P] where P = (Fo^2 + 2Fc^2)/3
3278 reflections	(Δ/σ)max < 0.001
277 parameters	Δρmax = 0.39 e Å^−3
0 restraints	Δρmin = −0.70 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Zn1	0.71408 (5)	0.64023 (4)	0.21196 (3)	0.03166 (13)
O6	0.9487 (4)	0.4284 (3)	0.2011 (2)	0.0620 (11)
O5	0.7705 (4)	0.5388 (3)	0.1179 (2)	0.0434 (8)
O4	0.6849 (4)	0.5057 (3)	−0.0439 (2)	0.0511 (9)
H4A	0.6873	0.5359	0.0025	0.077*
O3	1.5187 (4)	−0.2597 (3)	−0.0536 (2)	0.0570 (10)
H3A	1.5603	−0.2816	−0.0042	0.085*
O2	1.5791 (3)	−0.2637 (2)	0.10891 (19)	0.0375 (7)
O1	1.4725 (4)	−0.1395 (3)	0.17841 (18)	0.0508 (8)
O4W	0.5362 (4)	0.5313 (3)	0.2060 (3)	0.0535 (9)
O3W	0.8865 (4)	0.7510 (3)	0.2132 (3)	0.0501 (8)
O2W	0.6659 (4)	0.7520 (3)	0.3064 (2)	0.0493 (9)
O1W	0.8398 (4)	0.5403 (3)	0.3147 (2)	0.0431 (8)
N2	1.0930 (4)	0.1421 (3)	0.0030 (2)	0.0343 (7)
N1	1.1233 (4)	0.1052 (3)	−0.0637 (2)	0.0334 (8)
C14	0.8672 (5)	0.4557 (4)	0.1291 (3)	0.0402 (11)
C13	0.8783 (5)	0.3916 (3)	0.0511 (3)	0.0335 (9)
C12	0.7874 (5)	0.4192 (4)	−0.0312 (3)	0.0343 (9)
C11	0.7972 (5)	0.3553 (4)	−0.1026 (3)	0.0414 (10)
H11A	0.7367	0.3751	−0.1571	0.050*
C10	0.8949 (5)	0.2633 (4)	−0.0935 (3)	0.0372 (9)
H10A	0.8989	0.2196	−0.1414	0.045*
C9	0.9877 (5)	0.2357 (3)	−0.0127 (3)	0.0316 (9)
C8	0.9781 (5)	0.2998 (4)	0.0582 (3)	0.0370 (10)
H8A	1.0406	0.2807	0.1123	0.044*
C7	1.2236 (4)	0.0099 (3)	−0.0537 (3)	0.0322 (9)
C6	1.2416 (5)	−0.0349 (4)	−0.1298 (3)	0.0396 (10)
H6A	1.1871	−0.0025	−0.1822	0.048*
C5	1.3378 (6)	−0.1259 (4)	−0.1296 (3)	0.0473 (12)
H5A	1.3469	−0.1558	−0.1812	0.057*
C4	1.4210 (5)	−0.1727 (4)	−0.0517 (3)	0.0372 (10)
C3	1.4032 (4)	−0.1293 (4)	0.0259 (2)	0.0301 (8)
C2	1.3051 (5)	−0.0383 (3)	0.0244 (3)	0.0316 (9)
H2A	1.2936	−0.0093	0.0758	0.038*
C1	1.4901 (5)	−0.1794 (4)	0.1108 (3)	0.0321 (9)
H1WA	0.872 (6)	0.496 (5)	0.283 (4)	0.062 (18)*
H3WA	0.872 (7)	0.779 (5)	0.170 (4)	0.05 (2)*
H4WA	0.507 (9)	0.504 (6)	0.159 (5)	0.09 (3)*
H2WA	0.597 (7)	0.802 (5)	0.260 (4)	0.073 (19)*
H3WB	0.921 (7)	0.796 (6)	0.250 (5)	0.07 (2)*
H4WB	0.545 (7)	0.488 (5)	0.253 (4)	0.066 (19)*
H1WB	0.895 (8)	0.580 (6)	0.359 (4)	0.08 (2)*
H2WB	0.619 (8)	0.703 (6)	0.330 (5)	0.09 (3)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0368 (2)	0.0289 (2)	0.0260 (2)	0.0034 (2)	0.00388 (19)	0.0022 (2)
O6	0.076 (2)	0.070 (2)	0.0266 (18)	0.045 (2)	−0.0057 (17)	−0.0064 (16)
O5	0.0494 (18)	0.0396 (16)	0.0341 (18)	0.0196 (14)	0.0009 (13)	−0.0061 (13)
O4	0.056 (2)	0.0503 (18)	0.0372 (19)	0.0296 (16)	−0.0021 (15)	−0.0070 (15)
O3	0.076 (2)	0.062 (2)	0.0339 (19)	0.0451 (19)	0.0164 (18)	0.0057 (16)
O2	0.0453 (16)	0.0341 (14)	0.0297 (16)	0.0143 (13)	0.0057 (13)	0.0039 (12)
O1	0.068 (2)	0.0524 (16)	0.0286 (15)	0.0272 (18)	0.0085 (16)	0.0010 (16)
O4W	0.051 (2)	0.059 (2)	0.039 (2)	−0.0120 (16)	−0.0032 (17)	0.0131 (19)
O3W	0.060 (2)	0.055 (2)	0.030 (2)	−0.0195 (17)	0.0066 (17)	0.001 (2)
O2W	0.061 (2)	0.051 (2)	0.034 (2)	0.0169 (18)	0.0105 (16)	0.0009 (15)
O1W	0.0504 (19)	0.0440 (17)	0.0321 (19)	0.0105 (15)	0.0077 (14)	0.0042 (14)
N2	0.0380 (17)	0.0340 (15)	0.0279 (17)	0.0107 (16)	0.0052 (14)	0.0014 (16)
N1	0.0393 (18)	0.0326 (17)	0.0265 (18)	0.0100 (14)	0.0070 (15)	0.0019 (13)
C14	0.044 (2)	0.037 (2)	0.036 (3)	0.0115 (19)	0.0051 (19)	−0.0071 (19)
C13	0.039 (2)	0.0294 (19)	0.026 (2)	0.0077 (17)	−0.0003 (18)	−0.0018 (15)
C12	0.032 (2)	0.034 (2)	0.032 (2)	0.0076 (18)	0.0013 (16)	0.0019 (18)
C11	0.042 (2)	0.048 (2)	0.027 (2)	0.014 (2)	−0.0004 (18)	0.000 (2)
C10	0.047 (2)	0.039 (2)	0.023 (2)	0.0071 (19)	0.0049 (17)	−0.0056 (17)
C9	0.035 (2)	0.0302 (19)	0.028 (2)	0.0089 (16)	0.0061 (17)	−0.0002 (16)
C8	0.043 (2)	0.037 (2)	0.026 (2)	0.0108 (19)	0.0030 (18)	−0.0017 (18)
C7	0.035 (2)	0.0308 (19)	0.029 (2)	0.0071 (16)	0.0067 (17)	0.0030 (17)
C6	0.047 (3)	0.040 (2)	0.026 (2)	0.015 (2)	0.0027 (18)	0.0056 (18)
C5	0.068 (3)	0.049 (2)	0.023 (2)	0.020 (3)	0.009 (2)	−0.001 (2)
C4	0.046 (2)	0.034 (2)	0.031 (2)	0.0162 (18)	0.0108 (19)	0.0018 (17)
C3	0.035 (2)	0.0271 (17)	0.0262 (19)	0.0065 (17)	0.0064 (16)	0.0032 (17)
C2	0.035 (2)	0.0306 (19)	0.029 (2)	0.0051 (17)	0.0088 (17)	−0.0001 (17)
C1	0.036 (2)	0.0322 (19)	0.026 (2)	0.0039 (17)	0.0059 (17)	−0.0014 (16)

Geometric parameters (Å, º)

Zn1—O3W	2.055 (4)	N2—N1	1.267 (5)
Zn1—O4W	2.069 (4)	N2—C9	1.425 (5)
Zn1—O1W	2.075 (3)	N1—C7	1.413 (5)
Zn1—O2^i	2.086 (3)	C14—C13	1.487 (6)
Zn1—O5	2.097 (3)	C13—C8	1.385 (6)
Zn1—O2W	2.132 (3)	C13—C12	1.396 (6)
O6—C14	1.236 (6)	C12—C11	1.389 (6)
O5—C14	1.286 (5)	C11—C10	1.370 (6)
O4—C12	1.350 (5)	C11—H11A	0.9300
O4—H4A	0.8200	C10—C9	1.383 (6)
O3—C4	1.356 (5)	C10—H10A	0.9300
O3—H3A	0.8200	C9—C8	1.383 (6)
O2—C1	1.278 (5)	C8—H8A	0.9300
O2—Zn1^ii	2.086 (3)	C7—C2	1.387 (6)
O1—C1	1.240 (5)	C7—C6	1.389 (6)
O4W—H4WA	0.80 (8)	C6—C5	1.372 (6)
O4W—H4WB	0.88 (7)	C6—H6A	0.9300
O3W—H3WA	0.74 (6)	C5—C4	1.382 (6)
O3W—H3WB	0.78 (7)	C5—H5A	0.9300
O2W—H2WA	1.02 (7)	C4—C3	1.406 (6)
O2W—H2WB	0.87 (7)	C3—C2	1.381 (5)
O1W—H1WA	0.83 (6)	C3—C1	1.493 (5)
O1W—H1WB	0.88 (7)	C2—H2A	0.9300
O3W—Zn1—O4W	177.75 (16)	C12—C13—C14	121.8 (4)
O3W—Zn1—O1W	92.90 (16)	O4—C12—C11	117.9 (4)
O4W—Zn1—O1W	89.28 (15)	O4—C12—C13	121.6 (4)
O3W—Zn1—O2^i	89.72 (15)	C11—C12—C13	120.5 (4)
O4W—Zn1—O2^i	88.10 (14)	C10—C11—C12	120.7 (4)
O1W—Zn1—O2^i	177.36 (13)	C10—C11—H11A	119.7
O3W—Zn1—O5	87.93 (16)	C12—C11—H11A	119.7
O4W—Zn1—O5	91.35 (16)	C11—C10—C9	119.8 (4)
O1W—Zn1—O5	94.52 (13)	C11—C10—H10A	120.1
O2^i—Zn1—O5	85.89 (11)	C9—C10—H10A	120.1
O3W—Zn1—O2W	88.49 (17)	C8—C9—C10	119.4 (4)
O4W—Zn1—O2W	92.21 (18)	C8—C9—N2	116.8 (4)
O1W—Zn1—O2W	86.44 (15)	C10—C9—N2	123.8 (4)
O2^i—Zn1—O2W	93.32 (13)	C9—C8—C13	122.0 (4)
O5—Zn1—O2W	176.33 (15)	C9—C8—H8A	119.0
C14—O5—Zn1	128.2 (3)	C13—C8—H8A	119.0
C12—O4—H4A	109.5	C2—C7—C6	119.2 (4)
C4—O3—H3A	109.5	C2—C7—N1	125.4 (4)
C1—O2—Zn1^ii	128.5 (3)	C6—C7—N1	115.4 (3)
Zn1—O4W—H4WA	109 (6)	C5—C6—C7	121.6 (4)
Zn1—O4W—H4WB	114 (4)	C5—C6—H6A	119.2
H4WA—O4W—H4WB	122 (6)	C7—C6—H6A	119.2
Zn1—O3W—H3WA	109 (5)	C6—C5—C4	119.3 (4)
Zn1—O3W—H3WB	125 (5)	C6—C5—H5A	120.3
H3WA—O3W—H3WB	111 (7)	C4—C5—H5A	120.3
Zn1—O2W—H2WA	91 (3)	O3—C4—C5	117.9 (4)
Zn1—O2W—H2WB	101 (5)	O3—C4—C3	122.2 (4)
H2WA—O2W—H2WB	112 (5)	C5—C4—C3	119.9 (4)
Zn1—O1W—H1WA	93 (4)	C2—C3—C4	120.0 (3)
Zn1—O1W—H1WB	117 (4)	C2—C3—C1	119.0 (4)
H1WA—O1W—H1WB	125 (6)	C4—C3—C1	121.0 (4)
N1—N2—C9	114.4 (3)	C3—C2—C7	120.0 (4)
N2—N1—C7	117.7 (3)	C3—C2—H2A	120.0
O6—C14—O5	122.6 (4)	C7—C2—H2A	120.0
O6—C14—C13	120.1 (4)	O1—C1—O2	123.5 (4)
O5—C14—C13	117.3 (4)	O1—C1—C3	119.8 (4)
C8—C13—C12	117.6 (4)	O2—C1—C3	116.7 (4)
C8—C13—C14	120.6 (4)

Symmetry codes: (i) x−1, y+1, z; (ii) x+1, y−1, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1WA···O6	0.84 (6)	1.86 (6)	2.677 (5)	168 (6)
O1W—H1WB···N2^iii	0.88 (7)	2.32 (6)	3.058 (5)	143 (6)
O2W—H2WA···O1^i	1.01 (6)	1.63 (6)	2.636 (5)	170 (6)
O2W—H2WB···O3^iv	0.87 (7)	2.44 (8)	2.997 (5)	123 (6)
O3W—H3WA···N1^v	0.74 (6)	2.17 (6)	2.893 (5)	164 (5)
O3W—H3WB···O6^iii	0.78 (8)	1.95 (7)	2.664 (5)	152 (7)
O4W—H4WA···O4^vi	0.79 (7)	2.20 (8)	2.875 (6)	144 (8)
O4W—H4WB···O1^iii	0.89 (6)	1.85 (6)	2.703 (5)	160 (6)
O3—H3A···O2	0.82	1.80	2.528 (4)	147
O4—H4A···O5	0.82	1.81	2.537 (4)	148
C2—H2A···O1W^vii	0.93	2.53	3.405 (6)	157

Symmetry codes: (i) x−1, y+1, z; (iii) −x+2, y+1/2, −z+1/2; (iv) x−1, −y+1/2, z+1/2; (v) −x+2, −y+1, −z; (vi) −x+1, −y+1, −z; (vii) −x+2, y−1/2, −z+1/2.