Diaqua-bis(4-bromo-benzoato-κO,O')zinc(II).

The monomeric title Zn(II) complex, [Zn(C(7)H(4)BrO(2))(2)(H(2)O)(2)], contains two 4-bromo-benzoate (BB) ligands and two coordinated water mol-ecules around a Zn(II) atom on a twofold rotation axis. The BB ions act as bidentate ligands, with two very dissimilar coordination distances. The sixfold coordination around the Zn(II) may be described as highly distorted octa-hedral, with the two aqua ligands arranged cis. Hydrogen bonding involving the carboxyl-ate O atoms has an effect on the delocalization in the carboxyl-ate groups. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into chains parallel to the c axis and stacked along the b axis.

Related literature

For general background, see: Antolini et al. (1982 ▶); Chen & Chen (2002 ▶); Amiraslanov et al. (1979 ▶); Hauptmann et al. (2000 ▶); Shnulin et al. (1981 ▶); Antsyshkina et al. (1980 ▶); Adiwidjaja et al. (1978 ▶); Catterick et al. (1974 ▶). For related literature, see: Guseinov et al. (1984 ▶); Clegg et al. (1986a ▶,b ▶, 1987 ▶); Capilla & Aranda (1979 ▶); van Niekerk et al. (1953 ▶); Usubaliev et al. (1992 ▶); Musaev et al. (1983 ▶); Nadzhafov et al. (1981 ▶); Day & Selbin (1969 ▶); Amiraslanov et al. (1980 ▶); Necefoğlu et al. (2002 ▶); Hökelek et al. (2008 ▶, 2007 ▶); Hökelek & Necefoğlu (1996 ▶, 2001 ▶, 2007 ▶); Greenaway et al. (1984 ▶).

Experimental

Crystal data

[Zn(C7H4BrO2)2(H2O)2]

M = 501.43

Monoclinic,

a = 26.9067 (3) Å

b = 5.0704 (4) Å

c = 12.0371 (5) Å

β = 104.95 (2)°

V = 1586.6 (2) Å3

Z = 4

Mo Kα radiation

μ = 6.61 mm−1

T = 294 (2) K

0.25 × 0.20 × 0.15 mm

Data collection

Enraf–Nonius TurboCAD-4 diffractometer

Absorption correction: ψ scan (North et al., 1968 ▶) T min = 0.214, T max = 0.370

1648 measured reflections

1613 independent reflections

1133 reflections with I > 2σ(I)

R int = 0.031

3 standard reflections frequency: 120 min intensity decay: 1%

Refinement

R[F 2 > 2σ(F 2)] = 0.063

wR(F 2) = 0.166

S = 1.04

1613 reflections

113 parameters

4 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 1.42 e Å−3

Δρmin = −1.83 e Å−3

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ▶); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); 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 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808003759/bg2161sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808003759/bg2161Isup2.hkl

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

[Zn(C7H4BrO2)2(H2O)2]	F000 = 976
Mr = 501.43	Dx = 2.099 Mg m−3
Monoclinic, C2/c	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 25 reflections
a = 26.9067 (3) Å	θ = 6.7–10.8º
b = 5.0704 (4) Å	µ = 6.61 mm−1
c = 12.0371 (5) Å	T = 294 (2) K
β = 104.95 (2)º	Block, colourless
V = 1586.6 (2) Å3	0.25 × 0.20 × 0.15 mm
Z = 4

Enraf–Nonius TurboCAD-4 diffractometer	Rint = 0.031
Radiation source: fine-focus sealed tube	θmax = 26.3º
Monochromator: graphite	θmin = 3.1º
T = 294(2) K	h = −33→0
non–profiled ω scans	k = −6→0
Absorption correction: ψ scan(North et al., 1968)	l = −14→15
Tmin = 0.214, Tmax = 0.370	3 standard reflections
1648 measured reflections	every 120 min
1613 independent reflections	intensity decay: 1%
1133 reflections with I > 2σ(I)

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.063	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.166	w = 1/[σ2(Fo2) + (0.1112P)2] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max < 0.001
1613 reflections	Δρmax = 1.42 e Å−3
113 parameters	Δρmin = −1.83 e Å−3
4 restraints	Extinction correction: none
Primary atom site location: structure-invariant direct methods

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.

	x	y	z	Uiso*/Ueq
Br	1.22102 (3)	1.19239 (18)	0.64660 (7)	0.0502 (4)
Zn	1.0000	0.0782 (2)	0.2500	0.0335 (4)
O1	1.0587 (2)	0.3361 (10)	0.2873 (4)	0.0342 (12)
O2	1.0366 (2)	0.2503 (10)	0.4458 (4)	0.0379 (12)
O3	0.9709 (2)	−0.1998 (10)	0.3320 (4)	0.0404 (13)
H31	0.960 (4)	−0.19 (2)	0.403 (5)	0.09 (4)*
H32	0.953 (4)	−0.343 (15)	0.289 (7)	0.09 (4)*
C1	1.0641 (3)	0.3712 (14)	0.3959 (6)	0.0314 (16)
C2	1.1029 (3)	0.5711 (14)	0.4540 (5)	0.0292 (16)
C3	1.0994 (3)	0.6756 (16)	0.5586 (6)	0.0361 (17)
H3	1.0732	0.6214	0.5909	0.043*
C4	1.1352 (3)	0.8615 (16)	0.6150 (6)	0.0404 (19)
H4	1.1329	0.9337	0.6845	0.048*
C5	1.1735 (3)	0.9357 (14)	0.5673 (6)	0.0316 (16)
C6	1.1776 (3)	0.8399 (17)	0.4632 (7)	0.0415 (19)
H6	1.2036	0.8983	0.4311	0.050*
C7	1.1418 (3)	0.6525 (17)	0.4067 (6)	0.0392 (18)
H7	1.1442	0.5826	0.3369	0.047*

	U11	U22	U33	U12	U13	U23
Br	0.0509 (6)	0.0389 (5)	0.0485 (5)	−0.0172 (4)	−0.0093 (4)	0.0011 (4)
Zn	0.0403 (7)	0.0166 (6)	0.0429 (7)	0.000	0.0097 (5)	0.000
O1	0.050 (3)	0.028 (3)	0.021 (2)	0.001 (2)	0.002 (2)	−0.006 (2)
O2	0.049 (3)	0.030 (3)	0.031 (3)	−0.014 (2)	0.005 (2)	0.000 (2)
O3	0.068 (4)	0.023 (3)	0.030 (3)	−0.009 (3)	0.012 (3)	−0.004 (2)
C1	0.038 (4)	0.026 (4)	0.027 (3)	0.005 (3)	0.000 (3)	−0.001 (3)
C2	0.039 (4)	0.019 (3)	0.023 (3)	0.001 (3)	−0.003 (3)	−0.003 (3)
C3	0.045 (4)	0.041 (4)	0.026 (3)	−0.012 (4)	0.014 (3)	−0.008 (3)
C4	0.054 (5)	0.035 (4)	0.030 (4)	−0.011 (4)	0.008 (3)	−0.009 (3)
C5	0.037 (4)	0.024 (3)	0.025 (3)	−0.006 (3)	−0.007 (3)	0.003 (3)
C6	0.043 (4)	0.043 (5)	0.040 (4)	−0.007 (4)	0.014 (4)	0.002 (4)
C7	0.044 (4)	0.050 (5)	0.023 (3)	−0.006 (4)	0.007 (3)	−0.009 (3)

Br—C5	1.901 (7)	C1—C2	1.494 (10)
Zn—O1	2.010 (5)	C2—C3	1.392 (10)
Zn—O1i	2.010 (5)	C2—C7	1.376 (11)
Zn—O2	2.468 (5)	C3—H3	0.9300
Zn—O2i	2.468 (5)	C4—C3	1.393 (10)
Zn—O3	1.993 (5)	C4—H4	0.9300
Zn—O3i	1.993 (5)	C5—C4	1.354 (11)
O1—C1	1.289 (8)	C5—C6	1.375 (11)
O2—C1	1.230 (9)	C6—H6	0.9300
O3—H31	0.97 (7)	C7—C6	1.399 (11)
O3—H32	0.95 (8)	C7—H7	0.9300
O1—Zn—O1i	98.8 (3)	O2—C1—Zn	70.5 (4)
O1—Zn—O2	57.27 (18)	O2—C1—O1	120.1 (7)
O1i—Zn—O2	94.62 (19)	O2—C1—C2	123.0 (6)
O1—Zn—O2i	94.62 (19)	C2—C1—Zn	165.9 (5)
O1i—Zn—O2i	57.27 (18)	C3—C2—C1	118.7 (7)
O2—Zn—O2i	138.6 (3)	C7—C2—C1	121.6 (6)
O3i—Zn—O1	100.6 (2)	C7—C2—C3	119.7 (7)
O3—Zn—O1	137.4 (2)	C2—C3—C4	120.0 (7)
O3i—Zn—O1i	137.4 (2)	C2—C3—H3	120.0
O3—Zn—O1i	100.6 (2)	C4—C3—H3	120.0
O3i—Zn—O2	127.7 (2)	C3—C4—H4	120.4
O3—Zn—O2	83.58 (18)	C5—C4—C3	119.1 (7)
O3i—Zn—O2i	83.58 (18)	C5—C4—H4	120.4
O3—Zn—O2i	127.7 (2)	C4—C5—Br	117.6 (5)
O3i—Zn—O3	90.0 (3)	C4—C5—C6	122.5 (7)
C1—O1—Zn	101.1 (5)	C6—C5—Br	119.8 (6)
C1—O2—Zn	81.5 (4)	C5—C6—C7	118.3 (7)
Zn—O3—H32	119 (6)	C5—C6—H6	120.8
Zn—O3—H31	131 (6)	C7—C6—H6	120.8
H32—O3—H31	106 (4)	C2—C7—C6	120.3 (7)
O1—C1—Zn	49.6 (4)	C2—C7—H7	119.8
O1—C1—C2	116.8 (7)	C6—C7—H7	119.8
O1i—Zn—O1—C1	89.0 (4)	O1—C1—C2—C7	−19.9 (10)
O2—Zn—O1—C1	−0.8 (4)	O2—C1—C2—C7	162.8 (7)
O2i—Zn—O1—C1	146.6 (4)	Zn—C1—C2—C3	146.9 (18)
O3i—Zn—O1—C1	−129.1 (4)	Zn—C1—C2—C7	−33 (2)
O3—Zn—O1—C1	−27.4 (6)	O1—C1—C2—C3	160.3 (7)
C1i—Zn—O1—C1	118.5 (4)	O2—C1—C2—C3	−17.0 (11)
O1—Zn—O2—C1	0.9 (4)	C1—C2—C3—C4	179.7 (7)
O1i—Zn—O2—C1	−96.7 (4)	C7—C2—C3—C4	−0.1 (12)
O2i—Zn—O2—C1	−53.4 (4)	C1—C2—C7—C6	−180.0 (7)
O3i—Zn—O2—C1	78.2 (5)	C3—C2—C7—C6	−0.2 (12)
O3—Zn—O2—C1	163.1 (5)	C5—C4—C3—C2	−0.8 (12)
C1i—Zn—O2—C1	−78.8 (6)	Br—C5—C4—C3	179.4 (6)
Zn—O1—C1—O2	1.6 (8)	C6—C5—C4—C3	1.9 (12)
Zn—O1—C1—C2	−175.8 (5)	Br—C5—C6—C7	−179.6 (6)
Zn—O2—C1—O1	−1.3 (6)	C4—C5—C6—C7	−2.1 (12)
Zn—O2—C1—C2	175.9 (7)	C2—C7—C6—C5	1.2 (12)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H31···O2ii	0.97 (7)	1.82 (6)	2.746 (7)	157 (9)
O3—H32···O1iii	0.95 (8)	1.86 (8)	2.765 (7)	160 (9)

Table 1

Selected bond lengths (Å)

Zn—O1	2.010 (5)
Zn—O2	2.468 (5)
Zn—O3	1.993 (5)

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H31⋯O2i	0.97 (7)	1.82 (6)	2.746 (7)	157 (9)
O3—H32⋯O1ii	0.95 (8)	1.86 (8)	2.765 (7)	160 (9)

Symmetry codes: (i) ; (ii) .