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metal-organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 68| Part 8| August 2012| Page m1040
https://doi.org/10.1107/S160053681203036X

Bis(acetato-κO)bis­­(4,5-di­methyl­benzene-1,2-di­amine-κN)zinc

David K. Geigera*

aDepartment of Chemistry, State University of New York – College at Geneseo, 1 College Circle, Geneseo, NY 14454, USA
*Correspondence e-mail: geiger@geneseo.edu

(Received 2 July 2012; accepted 3 July 2012; online 10 July 2012)

The structure of the title compound, [Zn(CH3COO)2(C8H12N2)2], has one half molecule in the asymmetric unit. The ZnII atom is situated on a twofold rotation axis and is tetrahedrally coordinated by two N and two O atoms. The crystal packing displays inter­molecular N—H⋯O hydrogen bonds and intra­molecular N—H⋯O and N—H⋯N hydrogen bonding.

Related literature

For the role of complexes in biochemical systems with zinc in tetrahedral coordination, see: Parkin (2004[Parkin, G. (2004). Chem. Rev. 104, 699-768.]); Maret & Li (2009[Maret, W. & Li, Y. (2009). Chem. Rev. 109, 4682-4707.]). For the structure of the corresponding 1,2-diamino­benzene complex, see: Mei et al. (2009[Mei, L., Li, J., Ming, Z. S., Rong, L. Q. & Liang, L. X. (2009). Russ. J. Coord. Chem. 35, 871-873.]). For an example of a structurally characterized tetramine complex with zinc in tetrahedral coordination, see: Xu et al. (1998[Xu, X., Allen, C. S., Chuang, C.-L. & Canary, J. W. (1998). Acta Cryst. C54, 600-601.]). For an example carboxyl­ate coordination in a similar complex, see: Harding (2001[Harding, M. M. (2001). Acta Cryst. D57, 401-411.]).

[Scheme 1]

Experimental

Crystal data

  • [Zn(C2H3O2)2(C8H12N2)2]

  • Mr = 455.85

  • Monoclinic, C 2/c

  • a = 18.432 (3) Å

  • b = 4.7414 (6) Å

  • c = 25.740 (4) Å

  • β = 92.284 (4)°

  • V = 2247.8 (5) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 1.12 mm−1

  • T = 200 K

  • 0.80 × 0.30 × 0.20 mm
Data collection

  • Bruker SMART X2S benchtop diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2008b[Sheldrick, G. M. (2008b). SADABS. University of Göttingen, Germany.]) Tmin = 0.467, Tmax = 0.806

  • 11403 measured reflections

  • 1986 independent reflections

  • 1905 reflections with I > 2σ(I)

  • Rint = 0.046
Refinement

  • R[F2 > 2σ(F2)] = 0.036

  • wR(F2) = 0.094

  • S = 1.12

  • 1986 reflections

  • 151 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.67 e Å−3

  • Δρmin = −0.37 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N1—H1A⋯O1i 0.84 (4) 2.10 (4) 2.897 (3) 158 (3)
N2—H2A⋯O2 0.88 (3) 2.15 (3) 3.013 (3) 168 (3)
N2—H2B⋯N2ii 0.81 (4) 2.26 (4) 3.076 (3) 179 (3)
Symmetry codes: (i) [-x+1, y-1, -z+{\script{1\over 2}}]; (ii) [-x+{\script{3\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2010[Bruker (2010). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008a[Sheldrick, G. M. (2008a). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008a[Sheldrick, G. M. (2008a). Acta Cryst. A64, 112-122.]); molecular graphics: XSHELL (Bruker, 2004[Bruker (2004). XSHELL. Bruker AXS Inc., Madison, Wisconsin, USA.]) and Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]); software used to prepare material for publication: publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S160053681203036X/bv2208sup1.cif

Supporting information file. DOI: https://doi.org/10.1107/S160053681203036X/bv2208Isup2.cdx

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053681203036X/bv2208Isup3.hkl

checkCIF report


Comment top

Tetrahedrally coordinated zinc complexes play important structural (e.g., zinc fingers) and catalytic (e.g., carbonic anydrase) roles in biochemical systems (Parkin 2004, Maret & Li 2009). Although coordination via three amino acid residues (Zn—N coordination) and a water or hydroxide ligand is the most common coordination motif, carboxylate coordination is also known (Harding 2001). The title compound exhibits tetrahedral coordination involving two phenylenediamine ligands and two acetate ligands all coordinated in a monodentate fashion (see figure 1). The Zn atom sits on a twofold rotation axis resulting in a one-half molecule asymmetric unit. The complex exhibits intramolecular hydrogen bonding involving the uncoordinated amine nitrogen, N2, and the uncoordinated acetate oxygen, O2 (see figure 2). In addition, one of the H atoms of the coordinated amine is involved in two weak intramolecular hydrogen bonding intractions with the uncoordinated acetate oxygen atom (N1—H1B···O2 = 2.77 (3) Å, 114 (3)°) and the coordinated amine (N1—H1B···N2 = 2.57 (3) Å, 99 (3)°). An intermolecular hydrogen bonding network involving N2—H···N2 and N1—H···O1 interactions results in planes of molecules perpindicular to the c axis (see figure 3).

Related literature top

For the role of tetrahedrally coordinated zinc complexes in biochemical systems, see: Parkin (2004); Maret & Li (2009). For the structure of the corresponding 1,2-diaminobenzene complex, see: Mei et al. (2009). For an example of a structurally characterized tetrahedrally coordinated tetramine zinc complex, see: Xu et al. (1998). For an example carboxylate coordination in a simialar complex, see: Harding (2001).

Experimental top

The title compound was prepared by the reaction of two equivalents of 4,5-dimethyl-1,2-diaminobenzene with zinc(II) acetate dihydrate in refluxing ethanol. Slow evaporation of the solvent resulted in large, well formed crystals. The sample used for analysis was cut from a larger crystal. 1H NMR spectrum (CDCl3, 400 MHz, p.p.m.): 6.15 (4H, s), 3.89 (8H, b), 2.05 (12H, s), 1.92 (6H, s).

Refinement top

The structure was originally solved in the non-centrosymmetric space group Cc because the mean |E*E-1| statistic was 0.745. The structure refined to R1 = 0.051. However, many atoms displayed disc-shaped thermal ellipsoids and one of the nitrogen atoms coordinated to the zinc became nonpositive definite. Inverting the structure gave no improvement. Using TWIN resulted in a refined BASF of 0.49 with no significant improvement in the R1 value (0.048) or thermal parameters (the nitrogen remained nonpositive definite). The structure was subsequently solved and successfully refined in the centrosymmetric space group C2/c, which resulted in a lower R1 (0.0363)and much improved behavior of the thermal parameters. All H atoms atoms were found in difference fourier maps. Hydrogen atoms bonded to carbon atoms were refined using a riding model (AFIX 43 for aromatic C—H and AFIX 137 for methyl groups). The atomic coordinates and isotropic thermal parameters of all amine hydrogen atoms were refined.

Structure description top

Tetrahedrally coordinated zinc complexes play important structural (e.g., zinc fingers) and catalytic (e.g., carbonic anydrase) roles in biochemical systems (Parkin 2004, Maret & Li 2009). Although coordination via three amino acid residues (Zn—N coordination) and a water or hydroxide ligand is the most common coordination motif, carboxylate coordination is also known (Harding 2001). The title compound exhibits tetrahedral coordination involving two phenylenediamine ligands and two acetate ligands all coordinated in a monodentate fashion (see figure 1). The Zn atom sits on a twofold rotation axis resulting in a one-half molecule asymmetric unit. The complex exhibits intramolecular hydrogen bonding involving the uncoordinated amine nitrogen, N2, and the uncoordinated acetate oxygen, O2 (see figure 2). In addition, one of the H atoms of the coordinated amine is involved in two weak intramolecular hydrogen bonding intractions with the uncoordinated acetate oxygen atom (N1—H1B···O2 = 2.77 (3) Å, 114 (3)°) and the coordinated amine (N1—H1B···N2 = 2.57 (3) Å, 99 (3)°). An intermolecular hydrogen bonding network involving N2—H···N2 and N1—H···O1 interactions results in planes of molecules perpindicular to the c axis (see figure 3).

For the role of tetrahedrally coordinated zinc complexes in biochemical systems, see: Parkin (2004); Maret & Li (2009). For the structure of the corresponding 1,2-diaminobenzene complex, see: Mei et al. (2009). For an example of a structurally characterized tetrahedrally coordinated tetramine zinc complex, see: Xu et al. (1998). For an example carboxylate coordination in a simialar complex, see: Harding (2001).

Computing details top

Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker 2009); data reduction: SAINT (Bruker 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008a); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008a); molecular graphics: XSHELL (Bruker, 2004) and Mercury (Macrae et al., 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. Perspective view of the title compound with displacement ellipsoids of non-hydrogen atoms drawn at the 50% probability level.
[Figure 2] Fig. 2. Perspective view of the title compound displaying the intramolecular hydrogen bonding.
[Figure 3] Fig. 3. View of the unit cell of the title compound down the b axis displaying the intermolecular hydrogen bonding network.
Bis(acetato-κO)bis(4,5-dimethylbenzene-1,2-diamine-κN)zinc top
Crystal data top
[Zn(C2H3O2)2(C8H12N2)2]F(000) = 960
Mr = 455.85Dx = 1.347 Mg m−3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C2ycCell parameters from 5876 reflections
a = 18.432 (3) Åθ = 2.7–25.0°
b = 4.7414 (6) ŵ = 1.12 mm−1
c = 25.740 (4) ÅT = 200 K
β = 92.284 (4)°Plate, colourless
V = 2247.8 (5) Å30.80 × 0.30 × 0.20 mm
Z = 4
Data collection top
Bruker SMART X2S benchtop
diffractometer		1986 independent reflections
Radiation source: fine-focus sealed tube1905 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.046
ω scansθmax = 25.0°, θmin = 2.7°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2008b)		h = −21→21
Tmin = 0.467, Tmax = 0.806k = −5→5
11403 measured reflectionsl = −28→30
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)] = 0.036Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.094H atoms treated by a mixture of independent and constrained refinement
S = 1.12 w = 1/[σ2(Fo2) + (0.0434P)2 + 4.1592P]
where P = (Fo2 + 2Fc2)/3
1986 reflections(Δ/σ)max < 0.001
151 parametersΔρmax = 0.67 e Å−3
0 restraintsΔρmin = −0.37 e Å−3
Crystal data top
[Zn(C2H3O2)2(C8H12N2)2]V = 2247.8 (5) Å3
Mr = 455.85Z = 4
Monoclinic, C2/cMo Kα radiation
a = 18.432 (3) ŵ = 1.12 mm−1
b = 4.7414 (6) ÅT = 200 K
c = 25.740 (4) Å0.80 × 0.30 × 0.20 mm
β = 92.284 (4)°
Data collection top
Bruker SMART X2S benchtop
diffractometer		1986 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2008b)		1905 reflections with I > 2σ(I)
Tmin = 0.467, Tmax = 0.806Rint = 0.046
11403 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0360 restraints
wR(F2) = 0.094H atoms treated by a mixture of independent and constrained refinement
S = 1.12Δρmax = 0.67 e Å−3
1986 reflectionsΔρmin = −0.37 e Å−3
151 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. 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 (Å2) top
xyzUiso*/Ueq
Zn10.50000.21781 (8)0.25000.02608 (16)
O10.53194 (10)0.4948 (4)0.30352 (6)0.0343 (4)
O20.60458 (11)0.1492 (4)0.33024 (7)0.0421 (5)
N10.56934 (12)−0.0427 (5)0.21196 (8)0.0281 (5)
N20.69849 (13)0.2531 (6)0.23902 (9)0.0360 (6)
C10.60972 (12)0.0974 (5)0.17273 (9)0.0262 (5)
C20.67121 (13)0.2524 (5)0.18723 (10)0.0279 (6)
C30.70681 (14)0.3968 (6)0.14856 (10)0.0344 (6)
H30.74960.49990.15790.041*
C40.68215 (14)0.3954 (7)0.09706 (10)0.0364 (6)
C50.61975 (15)0.2423 (7)0.08302 (10)0.0383 (7)
C60.58503 (14)0.0931 (7)0.12132 (10)0.0351 (6)
H60.5431−0.01490.11190.042*
C70.5892 (2)0.2368 (9)0.02749 (12)0.0659 (12)
H7A0.54440.12540.02580.099*
H7B0.62480.15150.00490.099*
H7C0.57870.42980.01590.099*
C80.72326 (19)0.5613 (8)0.05768 (12)0.0553 (9)
H8A0.77080.61600.07290.083*
H8B0.69570.73100.04780.083*
H8C0.73000.44460.02680.083*
C90.57583 (14)0.3768 (6)0.33792 (9)0.0308 (6)
C100.58890 (18)0.5363 (7)0.38778 (11)0.0488 (8)
H10A0.62490.43600.40990.073*
H10B0.54330.55160.40590.073*
H10C0.60700.72560.38010.073*
H1A0.5413 (19)−0.167 (7)0.1990 (12)0.045 (9)*
H1B0.5973 (17)−0.120 (7)0.2345 (12)0.039 (8)*
H2A0.6658 (18)0.234 (6)0.2628 (12)0.039 (9)*
H2B0.7263 (18)0.383 (8)0.2448 (12)0.042 (9)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Zn10.0257 (2)0.0218 (2)0.0310 (2)0.0000.00465 (15)0.000
O10.0391 (10)0.0294 (10)0.0338 (9)0.0044 (8)−0.0066 (7)−0.0022 (8)
O20.0462 (12)0.0404 (13)0.0398 (10)0.0137 (10)0.0034 (8)0.0026 (9)
N10.0235 (10)0.0279 (13)0.0330 (11)−0.0022 (10)0.0030 (9)0.0003 (9)
N20.0251 (11)0.0492 (17)0.0336 (12)−0.0046 (11)−0.0011 (10)0.0021 (10)
C10.0210 (11)0.0258 (13)0.0323 (12)0.0021 (10)0.0053 (9)−0.0003 (10)
C20.0213 (12)0.0306 (15)0.0319 (12)0.0030 (10)0.0022 (9)−0.0002 (10)
C30.0232 (12)0.0393 (16)0.0410 (14)−0.0057 (12)0.0055 (10)−0.0013 (12)
C40.0315 (14)0.0424 (17)0.0360 (13)0.0002 (13)0.0101 (11)0.0045 (12)
C50.0327 (14)0.0525 (19)0.0297 (13)−0.0007 (13)0.0026 (11)0.0009 (12)
C60.0260 (13)0.0440 (17)0.0355 (13)−0.0073 (12)0.0033 (10)−0.0067 (12)
C70.053 (2)0.110 (4)0.0338 (16)−0.014 (2)−0.0010 (14)0.0017 (18)
C80.0550 (19)0.066 (2)0.0455 (17)−0.0125 (18)0.0163 (14)0.0110 (16)
C90.0298 (13)0.0311 (15)0.0314 (12)−0.0015 (11)0.0017 (10)0.0037 (11)
C100.066 (2)0.0427 (19)0.0368 (15)0.0084 (16)−0.0131 (14)−0.0038 (13)
Geometric parameters (Å, º) top
Zn1—O11.9759 (18)C3—H30.9500
Zn1—O1i1.9759 (18)C4—C51.395 (4)
Zn1—N12.054 (2)C4—C81.511 (4)
Zn1—N1i2.054 (2)C5—C61.390 (4)
O1—C91.302 (3)C5—C71.516 (4)
O2—C91.222 (3)C6—H60.9500
N1—C11.441 (3)C7—H7A0.9800
N1—H1A0.84 (4)C7—H7B0.9800
N1—H1B0.84 (3)C7—H7C0.9800
N2—C21.406 (3)C8—H8A0.9800
N2—H2A0.88 (3)C8—H8B0.9800
N2—H2B0.81 (4)C8—H8C0.9800
C1—C61.382 (3)C9—C101.501 (4)
C1—C21.389 (4)C10—H10A0.9800
C2—C31.394 (4)C10—H10B0.9800
C3—C41.384 (4)C10—H10C0.9800
O1—Zn1—O1i96.70 (10)C6—C5—C4118.6 (2)
O1—Zn1—N1123.94 (8)C6—C5—C7119.7 (3)
O1i—Zn1—N1103.95 (8)C4—C5—C7121.7 (3)
O1—Zn1—N1i103.95 (8)C1—C6—C5121.9 (2)
O1i—Zn1—N1i123.94 (8)C1—C6—H6119.1
N1—Zn1—N1i106.06 (13)C5—C6—H6119.1
C9—O1—Zn1110.40 (17)C5—C7—H7A109.5
C1—N1—Zn1113.93 (17)C5—C7—H7B109.5
C1—N1—H1A112 (2)H7A—C7—H7B109.5
Zn1—N1—H1A103 (2)C5—C7—H7C109.5
C1—N1—H1B111 (2)H7A—C7—H7C109.5
Zn1—N1—H1B108 (2)H7B—C7—H7C109.5
H1A—N1—H1B109 (3)C4—C8—H8A109.5
C2—N2—H2A115 (2)C4—C8—H8B109.5
C2—N2—H2B112 (2)H8A—C8—H8B109.5
H2A—N2—H2B113 (3)C4—C8—H8C109.5
C6—C1—C2119.9 (2)H8A—C8—H8C109.5
C6—C1—N1120.3 (2)H8B—C8—H8C109.5
C2—C1—N1119.6 (2)O2—C9—O1122.1 (2)
C1—C2—C3118.1 (2)O2—C9—C10121.8 (2)
C1—C2—N2120.9 (2)O1—C9—C10116.1 (2)
C3—C2—N2121.0 (2)C9—C10—H10A109.5
C4—C3—C2122.4 (2)C9—C10—H10B109.5
C4—C3—H3118.8H10A—C10—H10B109.5
C2—C3—H3118.8C9—C10—H10C109.5
C3—C4—C5119.1 (2)H10A—C10—H10C109.5
C3—C4—C8119.1 (3)H10B—C10—H10C109.5
C5—C4—C8121.8 (3)
Symmetry code: (i) −x+1, y, −z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O1ii0.84 (4)2.10 (4)2.897 (3)158 (3)
N2—H2A···O20.88 (3)2.15 (3)3.013 (3)168 (3)
N2—H2B···N2iii0.81 (4)2.26 (4)3.076 (3)179 (3)
Symmetry codes: (ii) −x+1, y−1, −z+1/2; (iii) −x+3/2, y+1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula[Zn(C2H3O2)2(C8H12N2)2]
Mr455.85
Crystal system, space groupMonoclinic, C2/c
Temperature (K)200
a, b, c (Å)18.432 (3), 4.7414 (6), 25.740 (4)
β (°) 92.284 (4)
V (Å3)2247.8 (5)
Z4
Radiation typeMo Kα
µ (mm−1)1.12
Crystal size (mm)0.80 × 0.30 × 0.20
Data collection
DiffractometerBruker SMART X2S benchtop
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2008b)
Tmin, Tmax0.467, 0.806
No. of measured, independent and
observed [I > 2σ(I)] reflections		11403, 1986, 1905
Rint0.046
(sin θ/λ)max (Å−1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.036, 0.094, 1.12
No. of reflections1986
No. of parameters151
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.67, −0.37

Computer programs: APEX2 (Bruker, 2010), SAINT (Bruker 2009), SHELXS97 (Sheldrick, 2008a), SHELXL97 (Sheldrick, 2008a), XSHELL (Bruker, 2004) and Mercury (Macrae et al., 2008), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O1i0.84 (4)2.10 (4)2.897 (3)158 (3)
N2—H2A···O20.88 (3)2.15 (3)3.013 (3)168 (3)
N2—H2B···N2ii0.81 (4)2.26 (4)3.076 (3)179 (3)
Symmetry codes: (i) −x+1, y−1, −z+1/2; (ii) −x+3/2, y+1/2, −z+1/2.
 

Acknowledgements

This work was supported by a congresssionally directed grant from the US Department of Education (grant No. P116Z100020) for the X-ray diffractometer.

References

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ISSN: 2056-9890
Volume 68| Part 8| August 2012| Page m1040
https://doi.org/10.1107/S160053681203036X
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