metal-organic compounds
Tris(ethane-1,2-diamine-κ2N,N′)zinc(II) tetrachloridozincate(II)
aDepartment of Physics, Presidency College (Autonomous), Chennai 600 005, India, and bDepartment of Chemistry, Pondicherry University, Pondicherry 605 014, India
*Correspondence e-mail: aspandian59@gmail.com
The title complex, [Zn(C2H8N2)3][ZnCl4], exists as discrete ions. The [Zn(C2H8N2)3]2+ cation exhibits a distorted octahedral shape. In the [ZnCl4]2− anion, the ZnII atom is in an almost regular tetrahedral environment. The crystal packing is consolidated by N—H⋯Cl and C—H⋯Cl hydrogen bonds.
Keywords: crystal structure; ethane-1,2-diamine; zinc(II) complex; hydrogen bonding; N—H⋯Cl and C—H⋯Cl interactions.
CCDC reference: 2001547
Structure description
Ethylenediamine (en) is a common chelating ligand that is widely used in transition-metal complexes. It cannot only chelate metal cations by two nitrogen atoms, but also offers hydrogen atoms to form N—H⋯X hydrogen bonds. Metal complexes containing an ethylenediamine (–NCH2CH2N) backbone have attracted significant interest as potential anticancer agents because of their rich redox chemistry and relative ease of manipulation (Mihajlović et al., 2012; Beaumont et al., 1976). Metal-containing compounds offer many advantages over conventional carbon-based compounds, their ability to coordinate ligands in a three-dimensional configuration allowing the functionalization of groups that can be tailored to defined molecular targets (Fricker, 2007; Meggers, 2009).
Metals such as zinc act as a key structural component in many proteins and enzymes, including transcription factors, cellular signalling proteins and DNA repair enzymes (Prasad, 1995; Prasad & Kucuk, 2002). Zinc deficiency during pregnancy may produce serious defects and foetal loss (Hernick & Fierke, 2005). Zinc also possesses antiviral, antibacterial and wound-healing properties with zinc complexes also being used in the treatment of gastrointestinal disorders, acne and infertility (Cunnane, 1988). Against this background, the X-ray structural characterization of the title compound has been carried out in order to determine the molecular conformation, binding modes and hydrogen-bonding interactions.
Fig. 1 shows the molecular entities of the title complex, [Zn(C2H8N2)3][ZnCl4], which comprises an ZnCl42− anion and a [Zn(en)3]2+complex cation. The ZnII atom of the tetrachloridozincate(II) anion is in an almost regular Cl4 tetrahedral environment, with Zn—Cl bond lengths in the range 2.255 (1)-2.272 (9) Å. The zinc cation displays a distorted octahedral coordination geometry defined by six N atoms from three ethylenediamine ligands, with Zn—N distances in the range of 2.173 (3)–2.219 (3) Å. The N—Zn—N angles of the en ligands are about 80°. They are noticeably smaller than the ideal octahedral angle of 90°. The five-membered chelate rings are non-planar, with N—C—C—N torsion angles of −57.5 (4), −55.4 (4) and −55.9 (5)°. All of the three en ligands assume a synclinal conformation about the C—C bond.
In the via intermolecular hydrogen bonds. The N—H⋯Cl hydrogen-bonding interactions between the N atoms of the ethylenediamine ligands and Cl atoms of the tetrachloridozincate anion connect the molecules, together with the weak C—H⋯Cl intramolecular interactions, generating a three-dimensional network (Fig. 2, Table 1).
adjacent ions are connectedSynthesis and crystallization
Zinc chloride (1.36 g, 2 mol) was dissolved in 25 ml of EtOH/H2O (1:4 v/v) mixture. To this solution, ethylenediamine (1.0 ml, 3 mol) in 25 ml of an HCl/EtOH (2:3 v/v) mixture was added dropwise. The mixture was stirred and heated to 338 K for 2 h and allowed to stand at room temperature until colourless crystals separated (3–4 weeks). Crystals suitable for single-crystal XRD were collected after recrystallization using acidified water.
Refinement
Crystal data, data collection and structure .
details are summarized in Table 2
|
Structural data
CCDC reference: 2001547
https://doi.org/10.1107/S2414314620006185/bt4091sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314620006185/bt4091Isup2.hkl
Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell
CrysAlis RED (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014/7 (Sheldrick, 2015); molecular graphics: PLATON (Spek, 2020); software used to prepare material for publication: SHELXL2014/7 (Sheldrick, 2015) and PLATON (Spek, 2020).[Zn(C2H8N2)3][ZnCl4] | F(000) = 920 |
Mr = 452.85 | Dx = 1.688 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 8.6916 (4) Å | Cell parameters from 2582 reflections |
b = 14.6035 (9) Å | θ = 3.9–25.0° |
c = 14.0382 (7) Å | µ = 3.29 mm−1 |
β = 91.201 (4)° | T = 293 K |
V = 1781.45 (16) Å3 | Block, colourless |
Z = 4 | 0.20 × 0.12 × 0.10 mm |
Oxford Diffraction Xcalibur diffractometer with EOS detector | 2582 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.027 |
ω and φ scans | θmax = 25.0°, θmin = 3.9° |
Absorption correction: multi-scan (CrysAlis Pro; Oxford Diffraction, 2009) | h = −10→9 |
Tmin = 0.629, Tmax = 0.720 | k = −16→17 |
10159 measured reflections | l = −16→16 |
3119 independent reflections |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.031 | H-atom parameters constrained |
wR(F2) = 0.075 | w = 1/[σ2(Fo2) + (0.0348P)2 + 0.9424P] where P = (Fo2 + 2Fc2)/3 |
S = 1.04 | (Δ/σ)max = 0.001 |
3119 reflections | Δρmax = 0.65 e Å−3 |
163 parameters | Δρmin = −0.35 e Å−3 |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
Refinement. All H atoms were fixed geometrically and allow to ride on their parent C and N atoms, with C—H distances of 0.97 Å and N—H distances of 0.90 Å, and with Uiso(H)= 1.2 Ueq(parent atom). |
x | y | z | Uiso*/Ueq | ||
C1 | 0.2695 (6) | 0.5672 (3) | 1.1390 (3) | 0.0762 (13) | |
H1A | 0.1936 | 0.5263 | 1.1654 | 0.091* | |
H1B | 0.3421 | 0.5307 | 1.1037 | 0.091* | |
C2 | 0.3510 (5) | 0.6156 (3) | 1.2166 (3) | 0.0711 (12) | |
H2A | 0.2773 | 0.6473 | 1.2556 | 0.085* | |
H2B | 0.4059 | 0.5717 | 1.2565 | 0.085* | |
C3 | 0.6033 (4) | 0.7154 (3) | 0.9023 (2) | 0.0504 (9) | |
H3A | 0.5510 | 0.7528 | 0.8546 | 0.061* | |
H3B | 0.6785 | 0.6777 | 0.8706 | 0.061* | |
C4 | 0.6819 (4) | 0.7751 (3) | 0.9736 (3) | 0.0515 (9) | |
H4A | 0.7429 | 0.7377 | 1.0173 | 0.062* | |
H4B | 0.7508 | 0.8166 | 0.9416 | 0.062* | |
C5 | 0.1177 (4) | 0.8682 (3) | 0.9718 (3) | 0.0620 (11) | |
H5A | 0.0297 | 0.8334 | 0.9930 | 0.074* | |
H5B | 0.0824 | 0.9108 | 0.9231 | 0.074* | |
C6 | 0.1881 (4) | 0.9199 (3) | 1.0543 (3) | 0.0588 (10) | |
H6A | 0.2718 | 0.9578 | 1.0323 | 0.071* | |
H6B | 0.1115 | 0.9596 | 1.0820 | 0.071* | |
N1 | 0.1919 (4) | 0.6337 (2) | 1.0733 (2) | 0.0579 (8) | |
H1C | 0.1079 | 0.6565 | 1.0997 | 0.069* | |
H1D | 0.1649 | 0.6066 | 1.0187 | 0.069* | |
N2 | 0.4594 (4) | 0.68128 (19) | 1.17780 (17) | 0.0474 (7) | |
H2C | 0.5472 | 0.6531 | 1.1646 | 0.057* | |
H2D | 0.4797 | 0.7247 | 1.2207 | 0.057* | |
N3 | 0.4909 (3) | 0.65660 (18) | 0.95024 (18) | 0.0420 (6) | |
H3C | 0.5393 | 0.6120 | 0.9820 | 0.050* | |
H3D | 0.4269 | 0.6313 | 0.9075 | 0.050* | |
N4 | 0.5683 (3) | 0.82833 (18) | 1.02757 (18) | 0.0399 (6) | |
H4C | 0.5424 | 0.8788 | 0.9955 | 0.048* | |
H4D | 0.6088 | 0.8449 | 1.0837 | 0.048* | |
N5 | 0.2326 (3) | 0.80599 (18) | 0.93231 (19) | 0.0427 (7) | |
H5C | 0.2959 | 0.8370 | 0.8951 | 0.051* | |
H5D | 0.1861 | 0.7630 | 0.8972 | 0.051* | |
N6 | 0.2461 (3) | 0.8549 (2) | 1.1263 (2) | 0.0489 (7) | |
H6C | 0.1687 | 0.8327 | 1.1598 | 0.059* | |
H6D | 0.3122 | 0.8826 | 1.1661 | 0.059* | |
Zn1 | 0.36240 (4) | 0.74282 (2) | 1.04903 (2) | 0.03245 (12) | |
Zn2 | 1.16044 (4) | 0.54507 (3) | 0.77627 (3) | 0.04177 (13) | |
Cl1 | 1.24823 (14) | 0.45660 (8) | 0.89729 (7) | 0.0752 (3) | |
Cl2 | 1.35279 (12) | 0.62417 (13) | 0.70905 (7) | 0.1022 (5) | |
Cl3 | 0.99364 (9) | 0.64689 (6) | 0.83974 (6) | 0.0446 (2) | |
Cl4 | 1.02570 (12) | 0.46530 (7) | 0.66406 (7) | 0.0646 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.113 (4) | 0.051 (3) | 0.066 (3) | −0.026 (3) | 0.019 (3) | 0.013 (2) |
C2 | 0.101 (4) | 0.064 (3) | 0.048 (2) | −0.003 (2) | 0.010 (2) | 0.015 (2) |
C3 | 0.040 (2) | 0.064 (2) | 0.048 (2) | 0.0067 (18) | 0.0081 (16) | −0.0030 (18) |
C4 | 0.0315 (18) | 0.062 (2) | 0.061 (2) | −0.0012 (17) | −0.0004 (16) | 0.0065 (19) |
C5 | 0.038 (2) | 0.065 (3) | 0.081 (3) | 0.0135 (19) | −0.0173 (19) | 0.003 (2) |
C6 | 0.047 (2) | 0.047 (2) | 0.082 (3) | 0.0155 (18) | −0.002 (2) | −0.007 (2) |
N1 | 0.057 (2) | 0.058 (2) | 0.0594 (19) | −0.0205 (16) | 0.0080 (15) | −0.0083 (16) |
N2 | 0.068 (2) | 0.0403 (17) | 0.0335 (14) | 0.0060 (15) | −0.0022 (13) | −0.0020 (12) |
N3 | 0.0433 (16) | 0.0411 (16) | 0.0414 (14) | 0.0048 (13) | −0.0033 (12) | −0.0036 (12) |
N4 | 0.0363 (15) | 0.0412 (16) | 0.0419 (14) | −0.0021 (12) | −0.0094 (11) | 0.0002 (13) |
N5 | 0.0381 (15) | 0.0406 (16) | 0.0489 (16) | −0.0051 (13) | −0.0142 (12) | 0.0005 (13) |
N6 | 0.0381 (16) | 0.0548 (19) | 0.0539 (17) | 0.0043 (14) | 0.0014 (13) | −0.0109 (15) |
Zn1 | 0.0331 (2) | 0.0308 (2) | 0.03334 (19) | −0.00077 (15) | −0.00142 (14) | 0.00084 (15) |
Zn2 | 0.0372 (2) | 0.0524 (3) | 0.0353 (2) | 0.01035 (18) | −0.00777 (16) | −0.00588 (18) |
Cl1 | 0.0995 (8) | 0.0657 (7) | 0.0594 (6) | 0.0405 (6) | −0.0250 (6) | 0.0033 (5) |
Cl2 | 0.0491 (7) | 0.2003 (17) | 0.0572 (6) | −0.0341 (8) | 0.0002 (5) | 0.0172 (8) |
Cl3 | 0.0429 (5) | 0.0360 (5) | 0.0546 (5) | 0.0064 (4) | −0.0047 (4) | −0.0084 (4) |
Cl4 | 0.0747 (7) | 0.0603 (6) | 0.0580 (6) | 0.0128 (5) | −0.0195 (5) | −0.0288 (5) |
C1—C2 | 1.467 (5) | N1—H1C | 0.8900 |
C1—N1 | 1.490 (5) | N1—H1D | 0.8900 |
C1—H1A | 0.9700 | N2—Zn1 | 2.173 (3) |
C1—H1B | 0.9700 | N2—H2C | 0.8900 |
C2—N2 | 1.458 (5) | N2—H2D | 0.8900 |
C2—H2A | 0.9700 | N3—Zn1 | 2.196 (2) |
C2—H2B | 0.9700 | N3—H3C | 0.8900 |
C3—N3 | 1.473 (4) | N3—H3D | 0.8900 |
C3—C4 | 1.483 (5) | N4—Zn1 | 2.208 (3) |
C3—H3A | 0.9700 | N4—H4C | 0.8900 |
C3—H3B | 0.9700 | N4—H4D | 0.8900 |
C4—N4 | 1.478 (4) | N5—Zn1 | 2.175 (2) |
C4—H4A | 0.9700 | N5—H5C | 0.8900 |
C4—H4B | 0.9700 | N5—H5D | 0.8900 |
C5—N5 | 1.468 (4) | N6—Zn1 | 2.219 (3) |
C5—C6 | 1.502 (5) | N6—H6C | 0.8900 |
C5—H5A | 0.9700 | N6—H6D | 0.8900 |
C5—H5B | 0.9700 | Zn2—Cl1 | 2.2546 (10) |
C6—N6 | 1.468 (4) | Zn2—Cl2 | 2.2552 (12) |
C6—H6A | 0.9700 | Zn2—Cl4 | 2.2654 (9) |
C6—H6B | 0.9700 | Zn2—Cl3 | 2.2718 (9) |
N1—Zn1 | 2.208 (3) | ||
C2—C1—N1 | 110.6 (3) | H2C—N2—H2D | 108.2 |
C2—C1—H1A | 109.5 | C3—N3—Zn1 | 107.77 (19) |
N1—C1—H1A | 109.5 | C3—N3—H3C | 110.2 |
C2—C1—H1B | 109.5 | Zn1—N3—H3C | 110.2 |
N1—C1—H1B | 109.5 | C3—N3—H3D | 110.2 |
H1A—C1—H1B | 108.1 | Zn1—N3—H3D | 110.2 |
N2—C2—C1 | 110.2 (3) | H3C—N3—H3D | 108.5 |
N2—C2—H2A | 109.6 | C4—N4—Zn1 | 108.9 (2) |
C1—C2—H2A | 109.6 | C4—N4—H4C | 109.9 |
N2—C2—H2B | 109.6 | Zn1—N4—H4C | 109.9 |
C1—C2—H2B | 109.6 | C4—N4—H4D | 109.9 |
H2A—C2—H2B | 108.1 | Zn1—N4—H4D | 109.9 |
N3—C3—C4 | 109.5 (3) | H4C—N4—H4D | 108.3 |
N3—C3—H3A | 109.8 | C5—N5—Zn1 | 108.9 (2) |
C4—C3—H3A | 109.8 | C5—N5—H5C | 109.9 |
N3—C3—H3B | 109.8 | Zn1—N5—H5C | 109.9 |
C4—C3—H3B | 109.8 | C5—N5—H5D | 109.9 |
H3A—C3—H3B | 108.2 | Zn1—N5—H5D | 109.9 |
N4—C4—C3 | 110.6 (3) | H5C—N5—H5D | 108.3 |
N4—C4—H4A | 109.5 | C6—N6—Zn1 | 107.1 (2) |
C3—C4—H4A | 109.5 | C6—N6—H6C | 110.3 |
N4—C4—H4B | 109.5 | Zn1—N6—H6C | 110.3 |
C3—C4—H4B | 109.5 | C6—N6—H6D | 110.3 |
H4A—C4—H4B | 108.1 | Zn1—N6—H6D | 110.3 |
N5—C5—C6 | 109.4 (3) | H6C—N6—H6D | 108.6 |
N5—C5—H5A | 109.8 | N2—Zn1—N5 | 171.16 (11) |
C6—C5—H5A | 109.8 | N2—Zn1—N3 | 95.43 (10) |
N5—C5—H5B | 109.8 | N5—Zn1—N3 | 91.72 (10) |
C6—C5—H5B | 109.8 | N2—Zn1—N1 | 79.79 (12) |
H5A—C5—H5B | 108.2 | N5—Zn1—N1 | 94.79 (11) |
N6—C6—C5 | 109.5 (3) | N3—Zn1—N1 | 92.04 (11) |
N6—C6—H6A | 109.8 | N2—Zn1—N4 | 92.64 (11) |
C5—C6—H6A | 109.8 | N5—Zn1—N4 | 93.80 (10) |
N6—C6—H6B | 109.8 | N3—Zn1—N4 | 79.26 (10) |
C5—C6—H6B | 109.8 | N1—Zn1—N4 | 167.95 (11) |
H6A—C6—H6B | 108.2 | N2—Zn1—N6 | 94.08 (11) |
C1—N1—Zn1 | 105.6 (2) | N5—Zn1—N6 | 79.69 (10) |
C1—N1—H1C | 110.6 | N3—Zn1—N6 | 167.09 (10) |
Zn1—N1—H1C | 110.6 | N1—Zn1—N6 | 98.21 (11) |
C1—N1—H1D | 110.6 | N4—Zn1—N6 | 91.62 (10) |
Zn1—N1—H1D | 110.6 | Cl1—Zn2—Cl2 | 111.51 (5) |
H1C—N1—H1D | 108.8 | Cl1—Zn2—Cl4 | 113.03 (4) |
C2—N2—Zn1 | 109.9 (2) | Cl2—Zn2—Cl4 | 110.45 (4) |
C2—N2—H2C | 109.7 | Cl1—Zn2—Cl3 | 106.75 (4) |
Zn1—N2—H2C | 109.7 | Cl2—Zn2—Cl3 | 108.28 (5) |
C2—N2—H2D | 109.7 | Cl4—Zn2—Cl3 | 106.52 (4) |
Zn1—N2—H2D | 109.7 | ||
N1—C1—C2—N2 | −55.9 (5) | C4—C3—N3—Zn1 | 45.2 (3) |
N3—C3—C4—N4 | −55.4 (4) | C3—C4—N4—Zn1 | 35.9 (3) |
N5—C5—C6—N6 | −57.5 (4) | C6—C5—N5—Zn1 | 41.1 (4) |
C2—C1—N1—Zn1 | 44.6 (4) | C5—C6—N6—Zn1 | 42.6 (3) |
C1—C2—N2—Zn1 | 36.6 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1D···Cl1i | 0.89 | 2.88 | 3.617 (3) | 142 |
N1—H1D···Cl3i | 0.89 | 2.95 | 3.677 (3) | 140 |
N2—H2C···Cl1ii | 0.89 | 2.56 | 3.426 (3) | 165 |
N2—H2D···Cl3iii | 0.89 | 2.51 | 3.395 (3) | 171 |
N3—H3C···Cl1ii | 0.89 | 2.67 | 3.500 (3) | 155 |
N3—H3D···Cl1i | 0.89 | 2.99 | 3.670 (3) | 135 |
N3—H3D···Cl2i | 0.89 | 2.85 | 3.600 (3) | 143 |
N4—H4C···Cl4iv | 0.89 | 2.63 | 3.437 (3) | 152 |
N4—H4D···Cl2iii | 0.89 | 2.76 | 3.581 (3) | 153 |
N5—H5C···Cl4iv | 0.89 | 2.58 | 3.431 (3) | 160 |
N5—H5D···Cl3i | 0.89 | 2.50 | 3.360 (3) | 162 |
N6—H6C···Cl2v | 0.89 | 2.91 | 3.646 (3) | 141 |
N6—H6D···Cl3iii | 0.89 | 2.91 | 3.652 (3) | 142 |
N6—H6D···Cl4iii | 0.89 | 2.90 | 3.609 (3) | 138 |
C3—H3B···Cl3 | 0.97 | 2.82 | 3.662 (3) | 146 |
Symmetry codes: (i) x−1, y, z; (ii) −x+2, −y+1, −z+2; (iii) x−1/2, −y+3/2, z+1/2; (iv) −x+3/2, y+1/2, −z+3/2; (v) x−3/2, −y+3/2, z+1/2. |
Acknowledgements
KA is thankful to the CSIR, New Delhi [Lr: No. 01 (2570)/12/EMR-II/3.4.2012] for financial support through a major research project. The authors are thankful to the Department of Chemistry, Pondicherry University, for the single-crystal XRD instrumentation facility.
Funding information
Funding for this research was provided by: Council of Scientific and Industrial Research, India (award No. 01 (2570)/12/EMR-II/3.4.2012 to K. Anbalagan).
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