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Acta Crystallogr Sect E Struct Rep Online. 2009 June 1; 65(Pt 6): o1352.
Published online 2009 May 20. doi:  10.1107/S1600536809018327
PMCID: PMC2969764

Ethyl­enediammonium dichloride


The title ionic compound, C2H10N2 2+·2Cl, crystallizes with a center of symmetry within the cation. Each of the positively charged ammonium ends of the mol­ecule is trigonally hydrogen bonded to three different chloride counter-ions, while each of the chloride ions is trigonally hydrogen bonded to three different ethyl­enediammonium cations. The hydrogen-bonding network leads to stabilization of the structure.

Related literature

For the applications of ethyl­enediamine, see: Kotti et al. (2006 [triangle]); Warner (1912 [triangle]).

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Object name is e-65-o1352-scheme1.jpg


Crystal data

  • C2H10N2 2+·2Cl
  • M r = 133.02
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-o1352-efi1.jpg
  • a = 4.3807 (3) Å
  • b = 6.8569 (4) Å
  • c = 9.9464 (5) Å
  • β = 91.192 (2)°
  • V = 298.71 (3) Å3
  • Z = 2
  • Cu Kα radiation
  • μ = 8.71 mm−1
  • T = 100 K
  • 0.45 × 0.30 × 0.29 mm

Data collection

  • Bruker SMART CCD APEXII area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Sheldrick, 2001 [triangle]) T min = 0.085, T max = 0.090
  • 1654 measured reflections
  • 521 independent reflections
  • 520 reflections with I > 2σ(I)
  • R int = 0.022


  • R[F 2 > 2σ(F 2)] = 0.028
  • wR(F 2) = 0.070
  • S = 1.15
  • 521 reflections
  • 44 parameters
  • Only H-atom coordinates refined
  • Δρmax = 0.41 e Å−3
  • Δρmin = −0.31 e Å−3

Data collection: APEX2 (Bruker, 2006 [triangle]); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005 [triangle]); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809018327/lh2823sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809018327/lh2823Isup2.hkl

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


The authors acknowledge support by the NSF-CRIF (grant No. 0443538).

supplementary crystallographic information


Ethylenediamine has been used for approximately one century in the preparation of many metal coordination complexes, such as tris(ethylenediamine)cobalt(III) chloride (Warner, 1912). This is an important precursor to many polymers, chelating agents and pharmaceuticals, including drug design (Kotti, et al., 2006). Since it is a widely used building block in the synthesis of many materials, its structure is of interest. However, it exists as a liquid at room temperature, with a melting point of 282K. We report herein the crystal structure of the dichloride salt of ethylenediamine.

Ethylenediammonium dichloride (I) crystallizes with a center of symmetry in the ethylene moiety. Fig. 1 shows the dication with one chloride counterion hydrogen bonded at each terminal nitrogen atom; however, there are three such chloride ions surrounding each N atom. The angles around both N1 and C1 are essentially tetrahedral, with the N1—C1—C1[1 - x,1/2 + y,2.5 - z] angle = 109.68 (18)°, and the angles around N1 range from 102 (2) to 115 (2) °.

Fig. 2 illustrates the packing of (I). Each of the chloride counterions is trigonally H bonded to three different ethylenediammonium cations with N···Cl bond distances of 3.1516 (15), 3.1931 (16) & 3.1749 (16) Å and angles N—H···Cl of 175 (2), 170 (2) & 173 (2) ° (see Table 1). Protonation occurs at both ammonium sites in the molecule (the 2nd is centrosymmetrically related); as a result, each nitrogen is also trigonally H bonded to three symmetry-related chlorides. This H bonding fixes both the chloride anions and the organic dication very rigidly in the lattice. Therefore, through symmetry, there exist six N—H···Cl bonds for each molecule, which leads to a great degree of stabilization in the structure.


Compound (I) was prepared by mixing 2.5 ml of ethylenediamine with 62 ml of water. Then 7.5 ml of 12 M HCl were added and this mixture was stirred in an ice bath at 273K until a white precipitate formed. The white precipitate was filtered and washed 3 times with methyl alcohol. The product was dissolved in water and then 12 M HCl was added until precipitation just began; a small quantity of water was then added to redissolve the precipitate. This mixture was allowed to evaporate slowly and large colorless needles of (I) formed, which were used directly for X-ray analyis.


All H atoms for (I) were found in electron density difference maps. The ammonium and methylene Hs' fractional coordinates were allowed to refine, but their isotropic thermal parameters were set at Uiso(H) = 1.5Ueq(N) and 1.2Ueq(C).


Fig. 1.
The molecluar structure of (I), with its numbering; one-half of the molecule is generated through a center of symmetry at 1/2,1/2,1/2 in the chosen unit cell. The H bonds to the chlorides are shown as dashed lines. Displacement ellipsoids are drawn at ...
Fig. 2.
A partial packing diagram for (I), with extracellular molecules, illustrating the trigonal hydrogen bonding of the chloride ion to three different ethylenediammonium cations. Also the three H atoms of the ammonium are bound to three different chloride ...

Crystal data

C2H10N22+·2ClF(000) = 140
Mr = 133.02Dx = 1.479 Mg m3
Monoclinic, P21/cCu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2ybcCell parameters from 1684 reflections
a = 4.3807 (3) Åθ = 4.5–67.4°
b = 6.8569 (4) ŵ = 8.71 mm1
c = 9.9464 (5) ÅT = 100 K
β = 91.192 (2)°Parallelepiped, colourless
V = 298.71 (3) Å30.45 × 0.30 × 0.29 mm
Z = 2

Data collection

Bruker SMART CCD APEXII area-detector diffractometer521 independent reflections
Radiation source: fine-focus sealed tube520 reflections with I > 2σ(I)
graphiteRint = 0.022
[var phi] and ω scansθmax = 67.8°, θmin = 7.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)h = −5→4
Tmin = 0.085, Tmax = 0.090k = −8→8
1654 measured reflectionsl = −11→11


Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.028Only H-atom coordinates refined
wR(F2) = 0.070w = 1/[σ2(Fo2) + (0.0415P)2 + 0.1865P] where P = (Fo2 + 2Fc2)/3
S = 1.15(Δ/σ)max < 0.001
521 reflectionsΔρmax = 0.41 e Å3
44 parametersΔρmin = −0.31 e Å3
0 restraintsExtinction correction: SHELXTL (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.066 (5)

Special details

Experimental. crystal mounted on cryoloop using Paratone-N
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)

Cl10.91302 (8)0.07997 (5)0.67014 (3)0.0043 (3)
C10.3856 (4)0.0762 (2)0.97532 (18)0.0037 (4)
H1A0.254 (5)0.019 (3)0.903 (2)0.004*
H1B0.269 (5)0.131 (3)1.047 (2)0.004*
N10.5508 (3)0.2442 (2)0.91610 (14)0.0044 (4)
H1C0.660 (5)0.305 (3)0.983 (2)0.007*
H1D0.444 (5)0.328 (4)0.885 (2)0.007*
H1E0.654 (5)0.206 (3)0.845 (2)0.007*

Atomic displacement parameters (Å2)

Cl10.0057 (3)0.0048 (3)0.0023 (3)−0.00036 (11)−0.00138 (18)−0.00050 (11)
C10.0017 (8)0.0051 (9)0.0041 (8)−0.0003 (6)−0.0013 (7)0.0001 (5)
N10.0067 (7)0.0032 (7)0.0031 (7)0.0013 (6)−0.0015 (6)0.0009 (5)

Geometric parameters (Å, °)

C1—N11.488 (2)N1—H1C0.91 (2)
C1—C1i1.522 (3)N1—H1D0.80 (3)
C1—H1A0.99 (2)N1—H1E0.89 (2)
C1—H1B0.96 (2)
N1—C1—C1i109.68 (18)C1—N1—H1C108.8 (13)
N1—C1—H1A107.3 (12)C1—N1—H1D114.8 (16)
C1i—C1—H1A109.4 (13)H1C—N1—H1D104 (2)
N1—C1—H1B105.1 (13)C1—N1—H1E110.4 (15)
C1i—C1—H1B112.8 (13)H1C—N1—H1E116 (2)
H1A—C1—H1B112.3 (17)H1D—N1—H1E102 (2)

Symmetry codes: (i) −x+1, −y, −z+2.

Hydrogen-bond geometry (Å, °)

N1—H1E···Cl10.89 (2)2.27 (2)3.1514 (15)175 (2)
N1—H1D···Cl1ii0.80 (3)2.39 (3)3.1770 (15)170 (2)
N1—H1C···Cl1iii0.91 (2)2.29 (2)3.1922 (15)171 (2)

Symmetry codes: (ii) −x+1, y+1/2, −z+3/2; (iii) x, −y+1/2, z+1/2.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: LH2823).


  • Bruker (2005). SAINT Bruker AXS Inc., Madison, Wisconsin, USA.
  • Bruker (2006). APEX2 Bruker AXS Inc., Madison, Wisconsin, USA.
  • Kotti, S. R. S. S., Timmons, C. & Li, G. (2006). Chem. Biol. Drug Des.67, 101–114. [PubMed]
  • Sheldrick, G. M. (2001). SADABS University of Göttingen, Germany.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Warner, A. (1912). Chem. Ber.45, 121–130.

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography