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ISSN: 2056-9890

Bis(4-amino­benzoic acid-κN)di­chloridozinc(II)

aDepartment of Chemistry, University of Pretoria, Pretoria 0002, South Africa
*Correspondence e-mail: melanie.rademeyer@up.ac.za

(Received 16 November 2010; accepted 17 November 2010; online 24 November 2010)

Mol­ecules of the title compound [ZnCl2(C7H7NO2)2], are located on a twofold rotation axis. Two 4-amino­benzoic acid moieties, and two chloride ligands are coordinated to a Zn atom in a tetra­hedral fashion, forming an isolated mol­ecule. Neighbouring mol­ecules are linked through hydrogen-bonded carboxyl groups, as well as N—H⋯Cl hydrogen-bonding inter­actions between amine groups and the chloride ligands of neighbouring mol­ecules, forming a three-dimensional network.

Related literature

For a related structure, see: Wang et al. (2002[Wang, R., Hong, M., Luo, J., Cao, R., Shi, Q. & Weng, J. (2002). Eur. J. Inorg. Chem. pp. 2904-2912.]). For hydrogen-bond motifs, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]).

[Scheme 1]

Experimental

Crystal data
  • [ZnCl2(C7H7NO2)2]

  • Mr = 410.56

  • Monoclinic, C 2/c

  • a = 30.646 (2) Å

  • b = 4.7248 (3) Å

  • c = 11.6157 (8) Å

  • β = 97.089 (1)°

  • V = 1669.05 (19) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 1.81 mm−1

  • T = 293 K

  • 0.42 × 0.09 × 0.07 mm

Data collection
  • Bruker (Siemens) P4 diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2001[Bruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.769, Tmax = 0.881

  • 4246 measured reflections

  • 1571 independent reflections

  • 1467 reflections with I > 2σ(I)

  • Rint = 0.026

Refinement
  • R[F2 > 2σ(F2)] = 0.029

  • wR(F2) = 0.077

  • S = 1.15

  • 1571 reflections

  • 105 parameters

  • H-atom parameters constrained

  • Δρmax = 0.33 e Å−3

  • Δρmin = −0.23 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O2—H1⋯O1i 0.80 1.82 2.609 (3) 170
N1—H1A⋯Cl1ii 0.90 2.64 3.5028 (17) 162
N1—H1B⋯Cl1iii 0.90 2.60 3.3978 (17) 148
Symmetry codes: (i) [-x+{\script{3\over 2}}, -y+{\script{3\over 2}}, -z+2]; (ii) -x+1, -y, -z+2; (iii) [-x+1, y-1, -z+{\script{3\over 2}}].

Data collection: SMART (Bruker, 2001[Bruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2001[Bruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]) and Mercury (Bruno et al., 2002[Bruno, I. J., Cole, J. C., Edgington, P. R., Kessler, M., Macrae, C. F., McCabe, P., Pearson, J. & Taylor, R. (2002). Acta Cryst. B58, 389-397.]); software used to prepare material for publication: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]) and WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).

Supporting information


Comment top

The crystal structure of dichloro-bis(4-aminobenzoic acid-N)-zinc(ii), I, was determined as part of an ongoing study of the coordination compounds formed between organic amines and metal halides. The related crystal structure of diiodo-bis(4-aminobenzoic acid-N)-cadmium(ii) has been reported (Wang et al., 2002), but the crystal structures are not isostructural.

The asymmetric unit of I consists of one 4-aminobenzoic acid moiety coordinated to a ZnCl unit through the nitrogen atom, as shown in Fig. 1, with the Zn atom lying on a twofold rotation axis. The second half of the molecule is generated by the symmetry operator (-x, y, 1/2 - z), and the unit cell contains four dichloro-bis(4-aminobenzoic acid-N)-zinc(II) molecules.

The Zn atom is coordinated to two 4-aminobenzamide ligands, through the nitrogen atom, and to two chloro ligands, and displays a slightly distorted tetrahedral coordination geometry with the N—Zn—N angle equal to 114.99 (9)°, which is slightly larger than the ideal tetrahedral angle of 109.5° to reduce steric hinderance between the two bulky 4-aminobenzoic acid ligands. The N—Zn—Cl angles adopt values of 107.10 (5)° and 109.27 (5)°, while the Cl—Zn—Cl angle has a value of 109.00 (3)°. The 4-aminobenzoic acid ligands show a cis orientation relative to the Zn atom, and in each ligand the aromatic plane forms an angle of 2.7 (0.1)° relative to the carboxylic acid group plane, rendering the ligand non-planar.

The layered packing of the molecules parallel to the bc-plane is illustrated in Fig. 2. The aromatic rings pack in two layers, while the Cl—Zn—Cl moieties form a layer. Hydrogen bonding interactions between the carboxylic acid groups of neighbouring layers result in the formation of carboxylic acid dimers of graph set notation R22(8) (Bernstein et al., 1995) on both sides of the molecule, forming a zigzag, one-dimensional hydrogen bonded ribbon as shown in Fig. 3. Neighbouring one-dimensional ribbons are connected via N1—H1B···Cl1 (symmetry operator: -x + 1, y - 1, -z + 3/2) hydrogen bonds to form the two-dimensional hydrogen bonded sheet illustrated in Fig. 3, with the intra-ribbon interactions described by the graph set notation R22(8). Additional N1—H1B···Cl1 (symmetry operator: -x + 1, -y, -z + 2) hydrogen bonds link neighbouring sheets to give a three-dimensional hydrogen bonded structure, with intra-sheet hydrogen bonds described by the graph set notation D11. Hydrogen bonding parameters are listed in Table 1.

Related literature top

For a related structure, see: Wang et al. (2002). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

Dichloro-bis(4-aminobenzoic acid-N)-zinc(ii) was prepared by dissolving 4.34 g Zn(NO3)2.6H2O (14.6 mmol, Sigma-Aldrich, 98%) and 1.00 g 4-aminobenzoic acid (7.29 mmol, Aldrich Chemistry, 99%) in a mixture of 50 ml distilled water and 50 ml e thanol (Merck, 99.5%). Dissolution was achieved by heating the solution in a beaker to approximately 60°C. Approximately 30 ml of the solution was transferred to a polytop vial, and one drop of HCl (Promark Chemicals, 32%) was added to the solution. Slow evaporation of the solvent mixture at room temperature gave yellow crystals of the title compound.

Refinement top

All H atoms, except the carboxylic acid group hydrogen atom, were refined using a riding model, with C—H distances of 0.93 Å and N—H distances of 0.90 Å, and Uiso(H) = 1.2Ueq(C) or 1.2Ueq(N). The carboxylic acid hydrogen atom was placed as observed on the difference Fourier map, and not further refined, with Uiso(H)=1.2Ueq(O).

Structure description top

The crystal structure of dichloro-bis(4-aminobenzoic acid-N)-zinc(ii), I, was determined as part of an ongoing study of the coordination compounds formed between organic amines and metal halides. The related crystal structure of diiodo-bis(4-aminobenzoic acid-N)-cadmium(ii) has been reported (Wang et al., 2002), but the crystal structures are not isostructural.

The asymmetric unit of I consists of one 4-aminobenzoic acid moiety coordinated to a ZnCl unit through the nitrogen atom, as shown in Fig. 1, with the Zn atom lying on a twofold rotation axis. The second half of the molecule is generated by the symmetry operator (-x, y, 1/2 - z), and the unit cell contains four dichloro-bis(4-aminobenzoic acid-N)-zinc(II) molecules.

The Zn atom is coordinated to two 4-aminobenzamide ligands, through the nitrogen atom, and to two chloro ligands, and displays a slightly distorted tetrahedral coordination geometry with the N—Zn—N angle equal to 114.99 (9)°, which is slightly larger than the ideal tetrahedral angle of 109.5° to reduce steric hinderance between the two bulky 4-aminobenzoic acid ligands. The N—Zn—Cl angles adopt values of 107.10 (5)° and 109.27 (5)°, while the Cl—Zn—Cl angle has a value of 109.00 (3)°. The 4-aminobenzoic acid ligands show a cis orientation relative to the Zn atom, and in each ligand the aromatic plane forms an angle of 2.7 (0.1)° relative to the carboxylic acid group plane, rendering the ligand non-planar.

The layered packing of the molecules parallel to the bc-plane is illustrated in Fig. 2. The aromatic rings pack in two layers, while the Cl—Zn—Cl moieties form a layer. Hydrogen bonding interactions between the carboxylic acid groups of neighbouring layers result in the formation of carboxylic acid dimers of graph set notation R22(8) (Bernstein et al., 1995) on both sides of the molecule, forming a zigzag, one-dimensional hydrogen bonded ribbon as shown in Fig. 3. Neighbouring one-dimensional ribbons are connected via N1—H1B···Cl1 (symmetry operator: -x + 1, y - 1, -z + 3/2) hydrogen bonds to form the two-dimensional hydrogen bonded sheet illustrated in Fig. 3, with the intra-ribbon interactions described by the graph set notation R22(8). Additional N1—H1B···Cl1 (symmetry operator: -x + 1, -y, -z + 2) hydrogen bonds link neighbouring sheets to give a three-dimensional hydrogen bonded structure, with intra-sheet hydrogen bonds described by the graph set notation D11. Hydrogen bonding parameters are listed in Table 1.

For a related structure, see: Wang et al. (2002). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); 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 Mercury (Bruno et al., 2002); software used to prepare material for publication: PLATON (Spek, 2009) and WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. The asymmetric unit of I showing the atomic numbering scheme. Displacement ellipsoids are shown at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
[Figure 2] Fig. 2. Packing diagram of I viewed down the b-axis.
[Figure 3] Fig. 3. O—H···O and N—H···Cl hydrogen bonding interactions link molecules to form a two-dimensional hydrogen bonded sheet.
Bis(4-aminobenzoic acid-κN)dichloridozinc(II) top
Crystal data top
[ZnCl2(C7H7NO2)2]F(000) = 832
Mr = 410.56Dx = 1.634 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 3472 reflections
a = 30.646 (2) Åθ = 2.7–26.3°
b = 4.7248 (3) ŵ = 1.81 mm1
c = 11.6157 (8) ÅT = 293 K
β = 97.089 (1)°Needle, yellow
V = 1669.05 (19) Å30.42 × 0.09 × 0.07 mm
Z = 4
Data collection top
Bruker P4
diffractometer
1571 independent reflections
Radiation source: fine-focus sealed tube1467 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.026
Detector resolution: 8.3 pixels mm-1θmax = 26.5°, θmin = 2.7°
φ and ω scansh = 3731
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
k = 25
Tmin = 0.769, Tmax = 0.881l = 1414
4246 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.029Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.077H-atom parameters constrained
S = 1.15 w = 1/[σ2(Fo2) + (0.0449P)2 + 0.8598P]
where P = (Fo2 + 2Fc2)/3
1571 reflections(Δ/σ)max = 0.001
105 parametersΔρmax = 0.33 e Å3
0 restraintsΔρmin = 0.23 e Å3
Crystal data top
[ZnCl2(C7H7NO2)2]V = 1669.05 (19) Å3
Mr = 410.56Z = 4
Monoclinic, C2/cMo Kα radiation
a = 30.646 (2) ŵ = 1.81 mm1
b = 4.7248 (3) ÅT = 293 K
c = 11.6157 (8) Å0.42 × 0.09 × 0.07 mm
β = 97.089 (1)°
Data collection top
Bruker P4
diffractometer
1571 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
1467 reflections with I > 2σ(I)
Tmin = 0.769, Tmax = 0.881Rint = 0.026
4246 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0290 restraints
wR(F2) = 0.077H-atom parameters constrained
S = 1.15Δρmax = 0.33 e Å3
1571 reflectionsΔρmin = 0.23 e Å3
105 parameters
Special details top

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.

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 (Å2) top
xyzUiso*/Ueq
O10.70214 (6)0.6634 (5)1.04917 (17)0.0663 (5)
O20.73024 (7)0.5084 (5)0.8932 (2)0.0778 (7)
H10.75240.59790.90590.093*
Zn10.50000.05824 (6)0.75000.02934 (14)
Cl10.468360 (16)0.33410 (10)0.87344 (4)0.03776 (16)
N10.54928 (5)0.1758 (3)0.84134 (14)0.0318 (3)
H1A0.53980.24310.90640.038*
H1B0.55570.32470.79810.038*
C10.58845 (6)0.0093 (4)0.87199 (17)0.0309 (4)
C20.62214 (7)0.0150 (5)0.8037 (2)0.0439 (5)
H20.62030.13280.73910.053*
C30.65871 (7)0.1553 (6)0.8315 (2)0.0501 (6)
H30.68140.15210.78530.060*
C40.66159 (7)0.3302 (5)0.92789 (19)0.0411 (5)
C50.62723 (7)0.3376 (5)0.99492 (18)0.0387 (5)
H50.62880.45651.05910.046*
C60.59051 (6)0.1691 (4)0.96695 (18)0.0360 (4)
H60.56740.17581.01170.043*
C70.70070 (8)0.5140 (6)0.9599 (2)0.0505 (6)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0514 (10)0.0825 (14)0.0654 (12)0.0282 (10)0.0087 (9)0.0222 (11)
O20.0481 (11)0.1041 (16)0.0851 (15)0.0392 (11)0.0233 (10)0.0285 (13)
Zn10.02820 (19)0.0287 (2)0.0304 (2)0.0000.00094 (13)0.000
Cl10.0445 (3)0.0359 (3)0.0343 (3)0.0004 (2)0.0108 (2)0.00444 (19)
N10.0320 (8)0.0267 (8)0.0351 (8)0.0014 (6)0.0016 (6)0.0025 (6)
C10.0285 (9)0.0281 (8)0.0343 (10)0.0003 (7)0.0030 (8)0.0048 (8)
C20.0378 (11)0.0516 (12)0.0424 (12)0.0025 (10)0.0047 (9)0.0115 (10)
C30.0333 (11)0.0677 (15)0.0511 (14)0.0081 (11)0.0125 (10)0.0099 (12)
C40.0310 (10)0.0460 (12)0.0450 (12)0.0077 (9)0.0001 (9)0.0007 (10)
C50.0388 (11)0.0401 (11)0.0363 (11)0.0069 (9)0.0011 (8)0.0034 (9)
C60.0338 (10)0.0382 (11)0.0365 (10)0.0041 (8)0.0064 (8)0.0000 (8)
C70.0367 (12)0.0598 (14)0.0548 (14)0.0138 (11)0.0045 (10)0.0021 (12)
Geometric parameters (Å, º) top
O1—C71.250 (3)C1—C61.383 (3)
O2—C71.262 (3)C2—C31.385 (3)
O2—H10.8000C2—H20.9300
Zn1—N1i2.0577 (15)C6—C51.384 (3)
Zn1—N12.0576 (15)C6—H60.9300
Zn1—Cl12.2445 (5)C5—C41.385 (3)
Zn1—Cl1i2.2445 (5)C5—H50.9300
N1—C11.443 (2)C7—C41.490 (3)
N1—H1A0.9000C4—C31.386 (3)
N1—H1B0.9000C3—H30.9300
C1—C21.378 (3)
C7—O2—H1122.00C1—C2—H2120.1
N1i—Zn1—N1114.98 (9)C3—C2—H2120.1
N1i—Zn1—Cl1107.10 (5)C1—C6—C5119.57 (19)
N1—Zn1—Cl1109.28 (5)C1—C6—H6120.2
N1i—Zn1—Cl1i109.28 (5)C5—C6—H6120.2
N1—Zn1—Cl1i107.10 (5)C6—C5—C4120.4 (2)
Cl1—Zn1—Cl1i109.00 (3)C6—C5—H5119.8
C1—N1—Zn1111.68 (11)C4—C5—H5119.8
C1—N1—H1A109.3O1—C7—O2124.5 (2)
Zn1—N1—H1A109.3O1—C7—C4118.8 (2)
C1—N1—H1B109.3O2—C7—C4116.7 (2)
Zn1—N1—H1B109.3C5—C4—C3119.5 (2)
H1A—N1—H1B107.9C5—C4—C7119.3 (2)
C2—C1—C6120.48 (19)C3—C4—C7121.2 (2)
C2—C1—N1120.46 (19)C2—C3—C4120.3 (2)
C6—C1—N1118.94 (18)C2—C3—H3119.9
C1—C2—C3119.8 (2)C4—C3—H3119.9
N1i—Zn1—N1—C1161.70 (15)C6—C5—C4—C30.8 (3)
Cl1—Zn1—N1—C177.86 (13)C6—C5—C4—C7179.9 (2)
Cl1i—Zn1—N1—C140.08 (14)O1—C7—C4—C52.5 (4)
Zn1—N1—C1—C295.8 (2)O2—C7—C4—C5177.1 (3)
Zn1—N1—C1—C680.33 (19)O1—C7—C4—C3178.4 (3)
C6—C1—C2—C31.2 (3)O2—C7—C4—C32.0 (4)
N1—C1—C2—C3177.2 (2)C1—C2—C3—C40.2 (4)
C2—C1—C6—C51.6 (3)C5—C4—C3—C21.2 (4)
N1—C1—C6—C5177.72 (18)C7—C4—C3—C2179.7 (2)
C1—C6—C5—C40.6 (3)
Symmetry code: (i) x+1, y, z+3/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H1···O1ii0.801.822.609 (3)170
N1—H1A···Cl1iii0.902.643.5028 (17)162
N1—H1B···Cl1iv0.902.603.3978 (17)148
Symmetry codes: (ii) x+3/2, y+3/2, z+2; (iii) x+1, y, z+2; (iv) x+1, y1, z+3/2.

Experimental details

Crystal data
Chemical formula[ZnCl2(C7H7NO2)2]
Mr410.56
Crystal system, space groupMonoclinic, C2/c
Temperature (K)293
a, b, c (Å)30.646 (2), 4.7248 (3), 11.6157 (8)
β (°) 97.089 (1)
V3)1669.05 (19)
Z4
Radiation typeMo Kα
µ (mm1)1.81
Crystal size (mm)0.42 × 0.09 × 0.07
Data collection
DiffractometerBruker P4
Absorption correctionMulti-scan
(SADABS; Bruker, 2001)
Tmin, Tmax0.769, 0.881
No. of measured, independent and
observed [I > 2σ(I)] reflections
4246, 1571, 1467
Rint0.026
(sin θ/λ)max1)0.628
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.029, 0.077, 1.15
No. of reflections1571
No. of parameters105
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.33, 0.23

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Bruno et al., 2002), PLATON (Spek, 2009) and WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H1···O1i0.801.822.609 (3)170
N1—H1A···Cl1ii0.902.643.5028 (17)162
N1—H1B···Cl1iii0.902.603.3978 (17)148
Symmetry codes: (i) x+3/2, y+3/2, z+2; (ii) x+1, y, z+2; (iii) x+1, y1, z+3/2.
 

Acknowledgements

Funding received for this work from the University of Pretoria is acknowledged.

References

First citationBernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573.  CrossRef CAS Web of Science Google Scholar
First citationBruker (2001). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruno, I. J., Cole, J. C., Edgington, P. R., Kessler, M., Macrae, C. F., McCabe, P., Pearson, J. & Taylor, R. (2002). Acta Cryst. B58, 389–397.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWang, R., Hong, M., Luo, J., Cao, R., Shi, Q. & Weng, J. (2002). Eur. J. Inorg. Chem. pp. 2904–2912.  CrossRef Google Scholar

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