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The crystal structure of the title compound, C8H22N22+·2Cl-·H2O, exhibits layered stacking in which the organic cations are separated by inorganic layers containing the chloride anions and the water molecules. The diammonium octane chain straddles a centre of inversion and the single water of crystallization sits on a twofold rotation axis. The diammonium octane chains pack in parallel layers with every second hydro­carbon layer alternating in a staggered configuration with respect to the previous layer. The three-dimensional hydrogen-bonding network links the organic and inorganic layers together in a highly intricate and complex manner. The torsion angles of the hydro­carbon chain deviate from 180° as a result of hydrogen-bonding inter­actions to the water mol­ecule and the surrounding chloride anions.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807045990/ez2101sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536807045990/ez2101Isup2.hkl
Contains datablock I

CCDC reference: 667334

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.002 Å
  • R factor = 0.034
  • wR factor = 0.097
  • Data-to-parameter ratio = 25.3

checkCIF/PLATON results

No syntax errors found



Alert level C PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ?
Alert level G PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature . 293 K
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 1 ALERT level C = Check and explain 2 ALERT level G = General alerts; check 3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check

Comment top

In an ongoing study of the structural characteristics of layered diammonium salts, we are determining the crystal structures of long-chained diammonium salts. Colourless crystals of octane-1,8-diammonium dichloride hydrate formed when we attempted to synthesize the unhydrated chloride salt. A search of the Cambridge Structural Database (Version 5.28, May 2007 release; Allen, 2002) revealed that only the octane-1,8-diammonium dibromide salt has previously been studied (Brisson & Brisse, 1984; Baur & Tillmanns, 1986) and the crystal structure of the title compound (I) had not previously been determined.

The diammonium octane chain straddles a centre of inversion and the single water of crystallization sits on a twofold rotation axis. Therefore the asymmetric unit contains one chloride anion, one half of the diammonium cation and one half of the water molecule (Figure 1).

Figure 2 illustrates the layered packing arrangement of the title compound (I). Single layers of the extended cations pack end on between two layers of chloride ions. Sandwiched in-between the chloride ions is a single layer of water molecules that hydrogen bonds to the chloride anions and the diammonium cations. The hydrocarbon chains pack in parallel layers with every second hydrocarbon chain layer alternating in a staggered, alternating configuration with respect to the previous layer. Since the packing configuration is a complex, staggered, alternating pattern, the hydrogen bonding network that is formed is an intricately complex bridge between the layers through the water molecules and chloride anions.

Figure 3 shows the hydrogen bonding contacts for the title compound (I). The hydrogen atoms around the ammonium group are involved in hydrogen bonds with two chloride anions and the oxygen of the water molecule. The hydrogen atoms of the water molecule hydrogen bond to a further two chloride anions resulting in four tetrahedrally oriented hydrogen bonds around the water molecule. The hydrogen bond distances and angles for (I) can be found in Table 1. Figure 3 also shows that the hydrocarbon chain is slightly twisted out of its fully extended configuration by up to 15° (where the torsion angles for a standard configuration hydrocarbon chain should be 180°). When examining the torsion angles (Table 2) along the hydrocarbon chain of (I) it is evident that the hydrogen bonding interactions to H1 attached to the water and the chloride anion affect the chain configuration.

Related literature top

For related structural studies of octane-1,8-diammonium salts see: Brisson & Brisse (1984); Baur & Tillmanns (1986). For related literature see: Allen (2002).

Experimental top

Compound (I) was prepared by adding 1,8-diamino-octane (0.50 g, 3.47 mmol) to 32% hydrochloric acid (2 ml, 69.1 mmol) in a sample vial. The mixture was then refluxed at 363 K for 2 h. The solution was cooled at 2 K h-1 to room temperature. Colourless crystals of octane-1,8-diammonium dichloride hydrate were collected and a suitable single-crystal was taken for the X-ray diffraction study.

Refinement top

H atoms were geometrically positioned and refined in the riding-model approximation, with C—H = 0.97 Å, N—H = 0.89 Å, and Uiso(H) = 1.2Ueq(C) or 1.5Ueq(N). For (I), the highest peak in the final difference map is 0.87 Å from Cl1 and the deepest hole is 1.03 Å from H1.

Structure description top

In an ongoing study of the structural characteristics of layered diammonium salts, we are determining the crystal structures of long-chained diammonium salts. Colourless crystals of octane-1,8-diammonium dichloride hydrate formed when we attempted to synthesize the unhydrated chloride salt. A search of the Cambridge Structural Database (Version 5.28, May 2007 release; Allen, 2002) revealed that only the octane-1,8-diammonium dibromide salt has previously been studied (Brisson & Brisse, 1984; Baur & Tillmanns, 1986) and the crystal structure of the title compound (I) had not previously been determined.

The diammonium octane chain straddles a centre of inversion and the single water of crystallization sits on a twofold rotation axis. Therefore the asymmetric unit contains one chloride anion, one half of the diammonium cation and one half of the water molecule (Figure 1).

Figure 2 illustrates the layered packing arrangement of the title compound (I). Single layers of the extended cations pack end on between two layers of chloride ions. Sandwiched in-between the chloride ions is a single layer of water molecules that hydrogen bonds to the chloride anions and the diammonium cations. The hydrocarbon chains pack in parallel layers with every second hydrocarbon chain layer alternating in a staggered, alternating configuration with respect to the previous layer. Since the packing configuration is a complex, staggered, alternating pattern, the hydrogen bonding network that is formed is an intricately complex bridge between the layers through the water molecules and chloride anions.

Figure 3 shows the hydrogen bonding contacts for the title compound (I). The hydrogen atoms around the ammonium group are involved in hydrogen bonds with two chloride anions and the oxygen of the water molecule. The hydrogen atoms of the water molecule hydrogen bond to a further two chloride anions resulting in four tetrahedrally oriented hydrogen bonds around the water molecule. The hydrogen bond distances and angles for (I) can be found in Table 1. Figure 3 also shows that the hydrocarbon chain is slightly twisted out of its fully extended configuration by up to 15° (where the torsion angles for a standard configuration hydrocarbon chain should be 180°). When examining the torsion angles (Table 2) along the hydrocarbon chain of (I) it is evident that the hydrogen bonding interactions to H1 attached to the water and the chloride anion affect the chain configuration.

For related structural studies of octane-1,8-diammonium salts see: Brisson & Brisse (1984); Baur & Tillmanns (1986). For related literature see: Allen (2002).

Computing details top

Data collection: SMART-NT (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 1999), PLATON (Spek, 2003) and publCIF (Westrip, 2007).

Figures top
[Figure 1] Fig. 1. Molecular structure of (I), with the atomic numbering scheme and displacement ellipsoids drawn at the 50% probability level. Atoms labelled with ' are at the symmetry position (1/2 - x, 1/2 - y, -z).
[Figure 2] Fig. 2. Packing arrangement of (I) viewed down the b axis (on the left) and the c axis (on the right). Hydrogen bonds are indicated by dashed lines.
[Figure 3] Fig. 3. Close-up view of (I) showing the hydrogen bonding contacts. Hydrogen bonds are indicated by dashed lines.
Octane-1,8-diammonium dichloride monohydrate top
Crystal data top
C8H22N22+·2Cl·H2OF(000) = 512
Mr = 235.19Dx = 1.178 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 1647 reflections
a = 24.719 (3) Åθ = 1.7–28.3°
b = 5.0827 (6) ŵ = 0.46 mm1
c = 10.8593 (14) ÅT = 293 K
β = 103.590 (3)°Block, colourless
V = 1326.2 (3) Å30.40 × 0.22 × 0.12 mm
Z = 4
Data collection top
Bruker SMART CCD area-detector
diffractometer
1647 independent reflections
Radiation source: fine-focus sealed tube1209 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.021
φ and ω scansθmax = 28.3°, θmin = 1.7°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2004)
h = 3229
Tmin = 0.837, Tmax = 0.947k = 65
3965 measured reflectionsl = 1410
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)] = 0.034Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.097All H-atom parameters refined
S = 1.04 w = 1/[σ2(Fo2) + (0.0507P)2 + 0.1994P]
where P = (Fo2 + 2Fc2)/3
1647 reflections(Δ/σ)max = 0.001
65 parametersΔρmax = 0.18 e Å3
0 restraintsΔρmin = 0.12 e Å3
Crystal data top
C8H22N22+·2Cl·H2OV = 1326.2 (3) Å3
Mr = 235.19Z = 4
Monoclinic, C2/cMo Kα radiation
a = 24.719 (3) ŵ = 0.46 mm1
b = 5.0827 (6) ÅT = 293 K
c = 10.8593 (14) Å0.40 × 0.22 × 0.12 mm
β = 103.590 (3)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
1647 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2004)
1209 reflections with I > 2σ(I)
Tmin = 0.837, Tmax = 0.947Rint = 0.021
3965 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0340 restraints
wR(F2) = 0.097All H-atom parameters refined
S = 1.04Δρmax = 0.18 e Å3
1647 reflectionsΔρmin = 0.12 e Å3
65 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
C10.62661 (7)0.6672 (3)0.20031 (15)0.0486 (4)
H1A0.62800.80930.26060.058*
H1B0.64980.71600.14330.058*
C20.64942 (7)0.4197 (3)0.27064 (15)0.0493 (4)
H2A0.65740.29240.21080.059*
H2B0.62140.34450.30940.059*
C30.70194 (6)0.4707 (3)0.37245 (14)0.0497 (4)
H3A0.69380.59770.43220.060*
H3B0.72980.54740.33350.060*
C40.72584 (6)0.2236 (3)0.44406 (14)0.0461 (4)
H4A0.69660.13530.47400.055*
H4B0.73820.10540.38600.055*
N10.56868 (5)0.6322 (3)0.12689 (13)0.0519 (3)
H1C0.56720.50020.07240.078*
H1D0.55700.77950.08460.078*
H1E0.54700.59600.17940.078*
Cl10.566023 (17)0.86236 (8)0.44656 (4)0.05515 (17)
O10.50000.2880 (4)0.25000.0574 (4)
H10.4814 (10)0.184 (5)0.192 (2)0.098 (8)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0510 (8)0.0405 (8)0.0498 (8)0.0002 (7)0.0030 (6)0.0041 (7)
C20.0507 (9)0.0385 (8)0.0519 (9)0.0024 (6)0.0013 (7)0.0033 (7)
C30.0501 (8)0.0419 (8)0.0517 (8)0.0004 (7)0.0010 (7)0.0043 (7)
C40.0471 (8)0.0414 (8)0.0458 (8)0.0024 (7)0.0032 (6)0.0019 (7)
N10.0520 (7)0.0473 (8)0.0524 (8)0.0094 (6)0.0042 (6)0.0102 (6)
Cl10.0640 (3)0.0467 (3)0.0507 (2)0.00232 (18)0.00525 (17)0.00322 (17)
O10.0654 (11)0.0490 (10)0.0520 (10)0.0000.0021 (8)0.000
Geometric parameters (Å, º) top
C1—N11.477 (2)C3—H3B0.9700
C1—C21.510 (2)C4—C4i1.514 (3)
C1—H1A0.9700C4—H4A0.9700
C1—H1B0.9700C4—H4B0.9700
C2—C31.517 (2)N1—H1C0.8900
C2—H2A0.9700N1—H1D0.8900
C2—H2B0.9700N1—H1E0.8900
C3—C41.522 (2)O1—H10.87 (2)
C3—H3A0.9700
N1—C1—C2111.86 (12)C2—C3—H3B108.9
N1—C1—H1A109.2C4—C3—H3B108.9
C2—C1—H1A109.2H3A—C3—H3B107.7
N1—C1—H1B109.2C4i—C4—C3113.70 (16)
C2—C1—H1B109.2C4i—C4—H4A108.8
H1A—C1—H1B107.9C3—C4—H4A108.8
C1—C2—C3112.36 (13)C4i—C4—H4B108.8
C1—C2—H2A109.1C3—C4—H4B108.8
C3—C2—H2A109.1H4A—C4—H4B107.7
C1—C2—H2B109.1C1—N1—H1C109.5
C3—C2—H2B109.1C1—N1—H1D109.5
H2A—C2—H2B107.9H1C—N1—H1D109.5
C2—C3—C4113.25 (13)C1—N1—H1E109.5
C2—C3—H3A108.9H1C—N1—H1E109.5
C4—C3—H3A108.9H1D—N1—H1E109.5
N1—C1—C2—C3164.65 (14)C2—C3—C4—C4i173.09 (17)
C1—C2—C3—C4179.66 (14)
Symmetry code: (i) x+3/2, y+1/2, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1C···Cl1ii0.892.293.1777 (15)175
N1—H1D···Cl1iii0.892.403.2215 (14)153
N1—H1E···O10.892.192.9660 (17)145
O1—H1···Cl1iv0.87 (2)2.34 (2)3.2036 (13)173 (2)
Symmetry codes: (ii) x, y+1, z1/2; (iii) x, y+2, z1/2; (iv) x+1, y1, z+1/2.

Experimental details

Crystal data
Chemical formulaC8H22N22+·2Cl·H2O
Mr235.19
Crystal system, space groupMonoclinic, C2/c
Temperature (K)293
a, b, c (Å)24.719 (3), 5.0827 (6), 10.8593 (14)
β (°) 103.590 (3)
V3)1326.2 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.46
Crystal size (mm)0.40 × 0.22 × 0.12
Data collection
DiffractometerBruker SMART CCD area-detector
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2004)
Tmin, Tmax0.837, 0.947
No. of measured, independent and
observed [I > 2σ(I)] reflections
3965, 1647, 1209
Rint0.021
(sin θ/λ)max1)0.666
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.034, 0.097, 1.04
No. of reflections1647
No. of parameters65
H-atom treatmentAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.18, 0.12

Computer programs: SMART-NT (Bruker, 1998), SAINT-Plus (Bruker, 1999), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006), WinGX (Farrugia, 1999), PLATON (Spek, 2003) and publCIF (Westrip, 2007).

Selected torsion angles (º) top
N1—C1—C2—C3164.65 (14)C2—C3—C4—C4i173.09 (17)
C1—C2—C3—C4179.66 (14)
Symmetry code: (i) x+3/2, y+1/2, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1C···Cl1ii0.892.293.1777 (15)175
N1—H1D···Cl1iii0.892.403.2215 (14)153
N1—H1E···O10.892.192.9660 (17)145
O1—H1···Cl1iv0.87 (2)2.34 (2)3.2036 (13)173 (2)
Symmetry codes: (ii) x, y+1, z1/2; (iii) x, y+2, z1/2; (iv) x+1, y1, z+1/2.
 

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