Biguanidinium dichloride.

The asymmetric unit of the title compound, C(2)H(9)N(5) (2+)·2Cl(-), is composed of one diprotonated biguanidinium cation and two chloride anions. The diprotonated cation consists of two planar halves twisted by 36.42 (6)°. The ions are associated in the crystal structure by extensive hydrogen bonding into a three-dimensional network; the diprotonated biguanidinium cation is hydrogen bonded to the chloride anions.

Related literature

For a general approach to the use of multiple-hydrogen-bonding DNA/RNA nucleobases as potential supra­molecular reagents, see: Portalone & Colapietro (2004 ▶, 2007 ▶ and references therein). For related crystal structures, see: Ernst (1977 ▶); Pinkerton & Schwarzenbach (1978 ▶); Martin & Pinkerton (1996 ▶); Martin et al. (1996 ▶, 1997 ▶); Kurzer & Pitchfork (1968 ▶).

Experimental

Crystal data

C2H9N5 2+·2Cl−

M = 174.04

Monoclinic,

a = 6.43693 (9) Å

b = 16.93420 (18) Å

c = 6.65260 (8) Å

β = 98.6878 (12)°

V = 716.84 (1) Å3

Z = 4

Mo Kα radiation

μ = 0.83 mm−1

T = 298 (2) K

0.20 × 0.20 × 0.15 mm

Data collection

Oxford Diffraction Xcalibur S CCD diffractometer

Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2006 ▶) T min = 0.852, T max = 0.886

80724 measured reflections

2456 independent reflections

2349 reflections with I > 2σ(I)

R int = 0.020

Refinement

R[F 2 > 2σ(F 2)] = 0.027

wR(F 2) = 0.070

S = 1.14

2456 reflections

119 parameters

All H-atom parameters refined

Δρmax = 0.14 e Å−3

Δρmin = −0.14 e Å−3

Data collection: CrysAlis CCD (Oxford Diffraction, 2006 ▶; cell refinement: CrysAlis RED (Oxford Diffraction, 2006 ▶; data reduction: CrysAlis RED; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808006144/kp2161sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808006144/kp2161Isup2.hkl

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

C2H9N52+·2Cl–	F000 = 360
Mr = 174.04	Dx = 1.613 Mg m−3
Monoclinic, P21/c	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 80724 reflections
a = 6.43693 (9) Å	θ = 3.2–32.0º
b = 16.93420 (18) Å	µ = 0.83 mm−1
c = 6.65260 (8) Å	T = 298 (2) K
β = 98.6878 (12)º	Plate, colourless
V = 716.841 (15) Å3	0.20 × 0.20 × 0.15 mm
Z = 4

Oxford Diffraction Xcalibur S CCD diffractometer	2456 independent reflections
Radiation source: Enhance (Mo) X-ray source	2349 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.020
Detector resolution: 16.0696 pixels mm-1	θmax = 32.0º
T = 298(2) K	θmin = 3.2º
ω and φ scans	h = −9→9
Absorption correction: multi-scan(CrysAlis RED; Oxford Diffraction, 2006)	k = −25→25
Tmin = 0.852, Tmax = 0.886	l = −9→9
80724 measured reflections

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	All H-atom parameters refined
R[F2 > 2σ(F2)] = 0.027	w = 1/[σ2(Fo2) + (0.0293P)2 + 0.2376P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.071	(Δ/σ)max < 0.001
S = 1.14	Δρmax = 0.14 e Å−3
2456 reflections	Δρmin = −0.14 e Å−3
119 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.110 (6)
Secondary atom site location: difference Fourier map

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.

	x	y	z	Uiso*/Ueq
Cl1	0.86502 (5)	−0.053995 (15)	0.27026 (4)	0.03288 (9)
Cl2	0.62775 (5)	0.315420 (18)	0.37349 (5)	0.03605 (9)
N1	0.35152 (13)	0.16618 (5)	0.32041 (15)	0.02556 (17)
H1	0.430 (3)	0.2034 (10)	0.356 (3)	0.039 (4)*
N2	0.00539 (15)	0.12772 (6)	0.20409 (16)	0.02955 (19)
H21	0.025 (3)	0.0812 (11)	0.243 (3)	0.038 (4)*
H22	−0.109 (3)	0.1408 (11)	0.130 (3)	0.048 (5)*
N3	0.09938 (18)	0.25798 (6)	0.21118 (17)	0.0335 (2)
H31	−0.025 (3)	0.2708 (11)	0.195 (3)	0.046 (5)*
H32	0.193 (3)	0.2941 (11)	0.232 (3)	0.044 (5)*
N4	0.38953 (17)	0.03968 (6)	0.18533 (15)	0.0304 (2)
H41	0.461 (3)	−0.0045 (12)	0.196 (3)	0.050 (5)*
H42	0.308 (3)	0.0513 (11)	0.078 (3)	0.047 (5)*
N5	0.62338 (15)	0.08686 (7)	0.45410 (16)	0.0324 (2)
H51	0.646 (3)	0.1178 (11)	0.556 (3)	0.044 (5)*
H52	0.711 (3)	0.0485 (11)	0.440 (3)	0.051 (5)*
C1	0.14797 (15)	0.18273 (5)	0.24248 (14)	0.02118 (17)
C2	0.45468 (15)	0.09538 (6)	0.31785 (15)	0.02354 (18)

	U11	U22	U33	U12	U13	U23
Cl1	0.04007 (15)	0.02213 (13)	0.03406 (15)	0.00402 (9)	−0.00208 (10)	−0.00296 (9)
Cl2	0.03243 (14)	0.03940 (16)	0.03375 (15)	−0.01269 (10)	−0.00333 (10)	0.00083 (10)
N1	0.0205 (4)	0.0213 (4)	0.0344 (4)	−0.0012 (3)	0.0024 (3)	−0.0021 (3)
N2	0.0220 (4)	0.0256 (4)	0.0390 (5)	−0.0017 (3)	−0.0020 (3)	0.0058 (4)
N3	0.0368 (5)	0.0215 (4)	0.0420 (6)	0.0052 (4)	0.0055 (4)	0.0047 (4)
N4	0.0379 (5)	0.0269 (4)	0.0257 (4)	0.0089 (4)	0.0022 (4)	−0.0017 (3)
N5	0.0253 (4)	0.0399 (5)	0.0312 (5)	0.0067 (4)	0.0010 (3)	0.0010 (4)
C1	0.0229 (4)	0.0203 (4)	0.0208 (4)	0.0012 (3)	0.0047 (3)	0.0022 (3)
C2	0.0218 (4)	0.0261 (4)	0.0238 (4)	0.0022 (3)	0.0068 (3)	0.0031 (3)

N1—C1	1.3634 (13)	N3—H32	0.857 (19)
N1—C2	1.3719 (13)	N4—C2	1.3156 (14)
N1—H1	0.819 (18)	N4—H41	0.88 (2)
N2—C1	1.3056 (13)	N4—H42	0.846 (19)
N2—H21	0.833 (18)	N5—C2	1.3131 (14)
N2—H22	0.852 (19)	N5—H51	0.853 (19)
N3—C1	1.3211 (13)	N5—H52	0.874 (19)
N3—H31	0.823 (19)
C1—N1—C2	127.89 (9)	H41—N4—H42	121.2 (17)
C1—N1—H1	117.6 (12)	C2—N5—H51	120.4 (12)
C2—N1—H1	113.6 (12)	C2—N5—H52	119.2 (13)
C1—N2—H21	122.9 (12)	H51—N5—H52	120.4 (17)
C1—N2—H22	116.6 (13)	N2—C1—N3	120.97 (10)
H21—N2—H22	120.4 (17)	N2—C1—N1	122.31 (9)
C1—N3—H31	118.5 (13)	N3—C1—N1	116.70 (9)
C1—N3—H32	121.3 (12)	N5—C2—N4	122.04 (10)
H31—N3—H32	119.0 (17)	N5—C2—N1	116.03 (10)
C2—N4—H41	116.7 (12)	N4—C2—N1	121.93 (9)
C2—N4—H42	119.7 (12)
C2—N1—C1—N2	19.96 (17)	C1—N1—C2—N5	−159.12 (10)
C2—N1—C1—N3	−161.49 (10)	C1—N1—C2—N4	21.55 (17)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl2	0.819 (18)	2.279 (18)	3.0796 (9)	166.0 (16)
N2—H21···Cl1i	0.833 (18)	2.530 (18)	3.2557 (10)	146.4 (15)
N2—H22···Cl2ii	0.852 (19)	2.34 (2)	3.1714 (10)	167.1 (17)
N3—H31···Cl2i	0.823 (19)	2.787 (19)	3.5098 (12)	147.8 (16)
N3—H32···Cl1iii	0.857 (19)	2.599 (19)	3.1933 (10)	127.4 (15)
N3—H32···Cl2	0.857 (19)	2.835 (19)	3.5454 (12)	141.3 (15)
N4—H41···Cl1	0.88 (2)	2.703 (19)	3.4178 (11)	139.4 (16)
N4—H42···Cl1iv	0.846 (19)	2.412 (19)	3.2295 (10)	162.8 (17)
N5—H51···Cl2v	0.853 (19)	2.413 (19)	3.2404 (12)	163.7 (16)
N5—H52···Cl1	0.874 (19)	2.369 (19)	3.1905 (11)	156.7 (17)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯Cl2	0.819 (18)	2.279 (18)	3.0796 (9)	166.0 (16)
N2—H21⋯Cl1i	0.833 (18)	2.530 (18)	3.2557 (10)	146.4 (15)
N2—H22⋯Cl2ii	0.852 (19)	2.34 (2)	3.1714 (10)	167.1 (17)
N3—H31⋯Cl2i	0.823 (19)	2.787 (19)	3.5098 (12)	147.8 (16)
N3—H32⋯Cl1iii	0.857 (19)	2.599 (19)	3.1933 (10)	127.4 (15)
N3—H32⋯Cl2	0.857 (19)	2.835 (19)	3.5454 (12)	141.3 (15)
N4—H41⋯Cl1	0.88 (2)	2.703 (19)	3.4178 (11)	139.4 (16)
N4—H42⋯Cl1iv	0.846 (19)	2.412 (19)	3.2295 (10)	162.8 (17)
N5—H51⋯Cl2v	0.853 (19)	2.413 (19)	3.2404 (12)	163.7 (16)
N5—H52⋯Cl1	0.874 (19)	2.369 (19)	3.1905 (11)	156.7 (17)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) .