7-Amino-heptyl-aza-nium iodide.

The absolute structure of the title compound, [H(3)N-(CH(2))(7)-NH(2)]I, has been determined from the diffraction experiment, the Flack parameter refining to -0.02 (2). In the crystal, adjacent symmetry-related cations are connected by head-to-tail R'H(2)N(+)-H⋯NH(2)R hydrogen bonds, forming chains along [010]. The remaining four H atoms attached to the amino and the aza-nium group form weak hydrogen bonds to neighbouring iodide anions, producing a three-dimensional hydrogen-bonded network. The amino group and the aliphatic chain of the 7-amino-heptyl-aza-nium cation show an exact all-trans conformation, within experimental uncertainties. The aza-nium group, to fulfill the needs of hydrogen bonding, is twisted out of the plane defined by the C atoms of the aliphatic chain, the C-C-C-N torsion angle being -65.4 (4)°.

Related literature

For the crystal structures of α-aza­niumyl-ω-amino­alkanes, see: Luciawati et al. (2011 ▶); Pienack et al. (2007 ▶); Natarajan et al. (1996 ▶); Qian et al. (2007 ▶). For α,ω-diaza­niumylalkane-containing compounds, see: Frank & Graf (2004 ▶); Jiang et al. (2010 ▶); Reiss (2010 ▶); Reiss & Engel (2002 ▶); Reiss & Engel (2004 ▶); Seidlhofer et al. (2010 ▶); Takeoka et al. (2005 ▶); Vizi et al. (2006 ▶). For dye-sensitized solar cells, see: Yang et al. (2011 ▶); Gorlov & Kloo (2008 ▶); Grätzel (2004 ▶). For graph-set analysis, see: Etter et al. (1990 ▶). For the profile fit on the powder diffraction data, see: Kraus & Nolze (2000 ▶). For background to hydrogen bonds, see: Steiner (2002 ▶).

Experimental

Crystal data

C7H19N2 +·I−

M = 258.14

Monoclinic,

a = 5.53418 (8) Å

b = 18.7308 (3) Å

c = 5.51570 (8) Å

β = 95.2195 (14)°

V = 569.39 (2) Å3

Z = 2

Mo Kα radiation

μ = 2.76 mm−1

T = 290 K

0.77 × 0.41 × 0.24 mm

Data collection

Oxford Diffraction Xcalibur Eos diffractometer

Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2009 ▶); analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by Clark & Reid (1995 ▶)] T min = 0.227, T max = 0.543

31566 measured reflections

2331 independent reflections

2325 reflections with I > 2σ(I)

R int = 0.028

Refinement

R[F 2 > 2σ(F 2)] = 0.017

wR(F 2) = 0.039

S = 1.03

2331 reflections

112 parameters

6 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.33 e Å−3

Δρmin = −0.48 e Å−3

Absolute structure: Flack (1983 ▶), 1130 Friedel pairs

Flack parameter: −0.02 (2)

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 2010 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811037329/wn2452sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811037329/wn2452Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811037329/wn2452Isup3.mol

Supplementary material file. DOI: 10.1107/S1600536811037329/wn2452Isup4.cml

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

C7H19N2+·I−	F(000) = 256
Mr = 258.14	Dx = 1.506 Mg m−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 29947 reflections
a = 5.53418 (8) Å	θ = 3.3–32.6°
b = 18.7308 (3) Å	µ = 2.76 mm−1
c = 5.51570 (8) Å	T = 290 K
β = 95.2195 (14)°	Block, colourless
V = 569.39 (2) Å3	0.77 × 0.41 × 0.24 mm
Z = 2

Oxford Diffraction Xcalibur Eos diffractometer	2331 independent reflections
Radiation source: fine-focus sealed tube	2325 reflections with I > 2σ(I)
Equatorial mounted graphite monochromator	Rint = 0.028
Detector resolution: 16.2711 pixels mm-1	θmax = 26.5°, θmin = 4.9°
ω scans	h = −6→6
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2009); analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by Clark & Reid (1995)]	k = −23→23
Tmin = 0.227, Tmax = 0.543	l = −6→6
31566 measured reflections

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.017	w = 1/[σ2(Fo2) + (0.010P)2 + 0.450P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.039	(Δ/σ)max = 0.001
S = 1.03	Δρmax = 0.33 e Å−3
2331 reflections	Δρmin = −0.48 e Å−3
112 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
6 restraints	Extinction coefficient: 0.0965 (15)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 1130 Friedel pairs
Secondary atom site location: difference Fourier map	Flack parameter: −0.02 (2)

Experimental. The Raman spectrum was measured using a Bruker MULTIRAM spectrometer (Nd:YAG-Laser at 1064 nm; RT-InGaAs-detector); 4000–70 cm-1: 3326(w), 3259(w), 2958(m), 2896(s), 2882(s), 2850(s), 2761(w), 1590(w), 1542(w), 1479(m), 1466(m), 1445(s), 1347(w), 1304(m), 1067(m), 1039(m), 961(w), 913(w), 858(w), 838(w), 340(w), 286(w), 253(w), 109(s). IR spectroscopic data were collected on a Digilab FT3400 spectrometer using a MIRacle ATR unit (Pike Technologies); 4000–560 cm-1: 3321(m), 3258(m), 3021(m, br), 2923(s), 2853(s), 1645(m, sh), 1568(m, br), 1487(m), 1465(m), 1384(m), 1359(w), 1334(m, sh), 1302(m), 1244(w), 1156(w), 929(w, br), 817(w), 723(w).

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
I1	0.09785 (3)	0.252871 (19)	0.24986 (3)	0.06035 (9)
N1	0.4322 (6)	0.34300 (16)	0.7843 (6)	0.0548 (7)
H11	0.330 (8)	0.342 (3)	0.653 (6)	0.108 (19)*
H12	0.335 (7)	0.337 (2)	0.905 (6)	0.075 (12)*
C1	0.5909 (7)	0.40516 (19)	0.8220 (7)	0.0524 (8)
H1A	0.7136	0.3956	0.9550	0.063*
H1B	0.4962	0.4458	0.8673	0.063*
C2	0.7123 (7)	0.42306 (16)	0.5974 (7)	0.0486 (7)
H2A	0.5885	0.4340	0.4667	0.058*
H2B	0.8003	0.3814	0.5490	0.058*
C3	0.8869 (7)	0.48553 (17)	0.6285 (7)	0.0515 (8)
H3A	0.7997	0.5269	0.6806	0.062*
H3B	1.0128	0.4742	0.7567	0.062*
C4	1.0042 (7)	0.50457 (18)	0.4032 (7)	0.0527 (8)
H4A	0.8785	0.5151	0.2739	0.063*
H4B	1.0945	0.4636	0.3528	0.063*
C5	1.1744 (6)	0.56805 (17)	0.4352 (7)	0.0488 (7)
H5A	1.0862	0.6083	0.4939	0.059*
H5B	1.3049	0.5565	0.5586	0.059*
C6	1.2828 (7)	0.58973 (17)	0.2052 (7)	0.0533 (8)
H6A	1.1515	0.5989	0.0803	0.064*
H6B	1.3756	0.5498	0.1506	0.064*
C7	1.4460 (7)	0.65486 (18)	0.2270 (7)	0.0517 (8)
H7A	1.5742	0.6471	0.3563	0.062*
H7B	1.5210	0.6612	0.0763	0.062*
N2	1.3108 (5)	0.72044 (13)	0.2795 (5)	0.0463 (6)
H21	1.416 (6)	0.755 (2)	0.249 (6)	0.087 (12)*
H22	1.196 (5)	0.7290 (18)	0.164 (5)	0.066 (12)*
H23	1.253 (5)	0.7189 (16)	0.427 (4)	0.047 (8)*

	U11	U22	U33	U12	U13	U23
I1	0.06054 (12)	0.07533 (14)	0.04638 (11)	−0.01293 (14)	0.01147 (7)	0.00061 (17)
N1	0.0556 (17)	0.0441 (14)	0.067 (2)	−0.0089 (14)	0.0171 (17)	0.0002 (13)
C1	0.061 (2)	0.0411 (17)	0.0565 (19)	−0.0083 (15)	0.0117 (17)	−0.0083 (14)
C2	0.0564 (19)	0.0362 (15)	0.055 (2)	−0.0084 (13)	0.0130 (16)	−0.0013 (13)
C3	0.057 (2)	0.0381 (16)	0.060 (2)	−0.0103 (14)	0.0082 (17)	−0.0036 (14)
C4	0.0567 (19)	0.0385 (15)	0.064 (2)	−0.0104 (14)	0.0097 (19)	−0.0037 (16)
C5	0.0537 (19)	0.0380 (16)	0.0556 (19)	−0.0085 (13)	0.0102 (16)	−0.0005 (13)
C6	0.062 (2)	0.0372 (16)	0.063 (2)	−0.0075 (15)	0.0138 (18)	−0.0065 (14)
C7	0.0499 (18)	0.0391 (16)	0.068 (2)	−0.0047 (14)	0.0155 (17)	−0.0021 (14)
N2	0.0582 (16)	0.0370 (11)	0.0448 (14)	0.0007 (12)	0.0106 (12)	0.0018 (10)

N1—C1	1.462 (4)	C4—H4B	0.9700
N1—H11	0.877 (19)	C5—C6	1.508 (5)
N1—H12	0.898 (19)	C5—H5A	0.9700
C1—C2	1.500 (5)	C5—H5B	0.9700
C1—H1A	0.9700	C6—C7	1.516 (5)
C1—H1B	0.9700	C6—H6A	0.9700
C2—C3	1.517 (4)	C6—H6B	0.9700
C2—H2A	0.9700	C7—N2	1.481 (4)
C2—H2B	0.9700	C7—H7A	0.9700
C3—C4	1.496 (5)	C7—H7B	0.9700
C3—H3A	0.9700	N2—H21	0.90 (2)
C3—H3B	0.9700	N2—H22	0.871 (18)
C4—C5	1.517 (4)	N2—H23	0.901 (18)
C4—H4A	0.9700
C1—N1—H11	118 (4)	H4A—C4—H4B	107.7
C1—N1—H12	112 (3)	C6—C5—C4	113.8 (3)
H11—N1—H12	103 (4)	C6—C5—H5A	108.8
N1—C1—C2	111.6 (3)	C4—C5—H5A	108.8
N1—C1—H1A	109.3	C6—C5—H5B	108.8
C2—C1—H1A	109.3	C4—C5—H5B	108.8
N1—C1—H1B	109.3	H5A—C5—H5B	107.7
C2—C1—H1B	109.3	C5—C6—C7	115.4 (3)
H1A—C1—H1B	108.0	C5—C6—H6A	108.4
C1—C2—C3	114.1 (3)	C7—C6—H6A	108.4
C1—C2—H2A	108.7	C5—C6—H6B	108.4
C3—C2—H2A	108.7	C7—C6—H6B	108.4
C1—C2—H2B	108.7	H6A—C6—H6B	107.5
C3—C2—H2B	108.7	N2—C7—C6	112.0 (3)
H2A—C2—H2B	107.6	N2—C7—H7A	109.2
C4—C3—C2	114.2 (3)	C6—C7—H7A	109.2
C4—C3—H3A	108.7	N2—C7—H7B	109.2
C2—C3—H3A	108.7	C6—C7—H7B	109.2
C4—C3—H3B	108.7	H7A—C7—H7B	107.9
C2—C3—H3B	108.7	C7—N2—H21	102 (3)
H3A—C3—H3B	107.6	C7—N2—H22	111 (2)
C3—C4—C5	113.7 (3)	H21—N2—H22	100 (3)
C3—C4—H4A	108.8	C7—N2—H23	112.1 (19)
C5—C4—H4A	108.8	H21—N2—H23	119 (3)
C3—C4—H4B	108.8	H22—N2—H23	112 (3)
C5—C4—H4B	108.8
N1—C1—C2—C3	−177.8 (3)	C3—C4—C5—C6	−177.0 (3)
C1—C2—C3—C4	−178.7 (3)	C4—C5—C6—C7	177.6 (3)
C2—C3—C4—C5	178.8 (3)	C5—C6—C7—N2	−65.4 (4)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H11···I1	0.88 (2)	2.98 (4)	3.738 (4)	145 (5)
N1—H12···I1i	0.90 (2)	2.88 (3)	3.706 (3)	153 (3)
N2—H21···N1ii	0.90 (2)	1.87 (3)	2.740 (4)	164 (5)
N2—H22···I1iii	0.87 (2)	2.72 (2)	3.579 (3)	170 (3)
N2—H23···I1iv	0.90 (2)	2.83 (2)	3.646 (3)	152 (2)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H11⋯I1	0.88 (2)	2.98 (4)	3.738 (4)	145 (5)
N1—H12⋯I1i	0.90 (2)	2.88 (3)	3.706 (3)	153 (3)
N2—H21⋯N1ii	0.90 (2)	1.87 (3)	2.740 (4)	164 (5)
N2—H22⋯I1iii	0.87 (2)	2.72 (2)	3.579 (3)	170 (3)
N2—H23⋯I1iv	0.90 (2)	2.83 (2)	3.646 (3)	152 (2)

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