Butane-1,4-diammonium diiodide

The crystal structure of the title compound, C₄H₁₄N₂²⁺·2I^-, exhibits ionic layers separated by hydro­carbon layers. The hydro­carbon layers stack in a herring-bone fashion and hydrogen bond to the iodide ions. The cation sits on a centre of inversion. The structure is compared with that of the related material butane-1,4-diammonium dichloride.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.019
• wR factor = 0.048
• Data-to-parameter ratio = 24.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   2 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

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Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus; 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 DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2003).

Butane-1,4-diammonium diiodide

Crystal data

C4H14N2^2+·2I^−	F(000) = 316
Mr = 343.97	Dx = 2.211 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 857 reflections
a = 4.8983 (8) Å	θ = 2.9–28.2°
b = 8.8210 (14) Å	µ = 6.02 mm^−1
c = 11.981 (2) Å	T = 293 K
β = 93.711 (3)°	Block, colourless
V = 516.61 (15) Å^3	0.24 × 0.18 × 0.18 mm
Z = 2

Data collection

Bruker SMART CCD area-detector diffractometer	890 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.054
Absorption correction: integration (XPREP; Bruker, 1999)	θmax = 25.5°, θmin = 2.9°
Tmin = 0.262, Tmax = 0.455	h = −5→5
4077 measured reflections	k = −10→10
954 independent reflections	l = −14→14

Refinement

Refinement on F^2	H-atom parameters constrained
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.0253P)^2 + 0.1016P] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.019	(Δ/σ)max = 0.001
wR(F^2) = 0.048	Δρmax = 0.60 e Å^−3
S = 1.05	Δρmin = −0.59 e Å^−3
954 reflections	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
39 parameters	Extinction coefficient: 0.096 (3)
0 restraints

Special details

Experimental. Numerical integration absorption corrections based on indexed crystal faces were applied using the XPREP routine (Bruker, 1999)

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1	0.8959 (5)	0.8113 (3)	0.1149 (2)	0.0461 (5)
H1A	0.7745	0.8451	0.0623	0.069*
H1B	0.999	0.8881	0.1412	0.069*
H1C	0.8085	0.7705	0.1704	0.069*
C1	1.0728 (6)	0.6946 (3)	0.0663 (2)	0.0417 (6)
H1D	1.2137	0.6635	0.1222	0.05*
H1E	1.1621	0.7381	0.0039	0.05*
C2	0.9085 (6)	0.5577 (3)	0.0266 (2)	0.0408 (6)
H2A	0.7636	0.589	−0.0275	0.049*
H2B	0.8247	0.5116	0.0895	0.049*
I1	0.59796 (4)	0.60023 (2)	0.335394 (13)	0.04429 (15)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0579 (15)	0.0353 (12)	0.0459 (12)	−0.0046 (11)	0.0096 (10)	−0.0031 (11)
C1	0.0454 (15)	0.0394 (14)	0.0405 (13)	0.0011 (12)	0.0036 (11)	−0.0049 (12)
C2	0.0426 (14)	0.0388 (13)	0.0413 (14)	−0.0016 (13)	0.0059 (11)	−0.0009 (12)
I1	0.05078 (19)	0.04570 (19)	0.03656 (17)	−0.00203 (7)	0.00415 (9)	0.00546 (6)

Geometric parameters (Å, º)

N1—C1	1.488 (3)	C1—H1D	0.97
N1—H1A	0.89	C1—H1E	0.97
N1—H1B	0.89	C2—C2^i	1.524 (5)
N1—H1C	0.89	C2—H2A	0.97
C1—C2	1.511 (4)	C2—H2B	0.97
C1—N1—H1A	109.5	N1—C1—H1E	109.4
C1—N1—H1B	109.5	C2—C1—H1E	109.4
H1A—N1—H1B	109.5	H1D—C1—H1E	108
C1—N1—H1C	109.5	C1—C2—C2^i	110.5 (3)
H1A—N1—H1C	109.5	C1—C2—H2A	109.6
H1B—N1—H1C	109.5	C2^i—C2—H2A	109.6
N1—C1—C2	111.4 (2)	C1—C2—H2B	109.6
N1—C1—H1D	109.4	C2^i—C2—H2B	109.6
C2—C1—H1D	109.4	H2A—C2—H2B	108.1
N1—C1—C2—C2^i	177.9 (3)

Symmetry code: (i) −x+2, −y+1, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···I1^ii	0.89	2.84	3.650 (3)	152
N1—H1B···I1^iii	0.89	2.72	3.578 (2)	162
N1—H1C···I1	0.89	2.74	3.616 (3)	170

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