5-Iodo­pyrimidin-2-amine

The mol­ecule of the title compound, C₄H₄IN₃, has crystallographic mirror plane symmetry. In the crystal, the mol­ecules are connected through N—H⋯N hydrogen bonds into polymeric tapes extended along the a axis, which are typical of 2-amino­pyrimidines. Each mol­ecule acts as a double donor and a double acceptor in the hydrogen bonding.

Related literature

For coordination polymers formed with the title compound, see: Lin et al. (2006).

Experimental

Crystal data

• C₄H₄IN₃

• M_r = 221.00

• Orthorhombic, C m c a

• a = 7.9088 (7) Å

• b = 8.3617 (10) Å

• c = 18.3821 (16) Å

• V = 1215.6 (2) ų

• Z = 8

• Mo Kα radiation

• μ = 5.16 mm⁻¹

• T = 295 K

• 0.6 × 0.4 × 0.2 mm

Data collection

• Bruker P4 diffractometer

• Absorption correction: multi-scan (XSCANS; Siemens, 1995) T_min = 0.332, T_max = 1.000

• 800 measured reflections

• 573 independent reflections

• 535 reflections with I > 2σ(I)

• R_int = 0.032

• 3 standard reflections every 97 reflections intensity decay: none

Refinement

• R[F² > 2σ(F²)] = 0.032

• wR(F²) = 0.089

• S = 1.10

• 573 reflections

• 48 parameters

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.93 e Å⁻³

• Δρ_min = −0.83 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2N⋯N1^i	0.79 (5)	2.37 (5)	3.157 (4)	173 (6)
Symmetry code: (i) .

Data collection: XSCANS (Siemens, 1995); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

S1. Comment

A series of Ag(I) coordination polymers containg 2-amino-5-iodopyrimidine have been prepared, which show metallocycles and one-dimensional helical chains (Lin, et al., 2006). Within this project the crystal structure of 2-amino-5-iodopyrimidine was determined to investigate its weak interactions.

In its crystal structure weak intermolecular N—H···N hydrogen bonding is found (Tab. 1) and the molecules are almost planar (Fig. 1).

Related literature

For coordination polymers formed with the title compound, see: Lin et al. (2006).

S2. Experimental

The title compound was purchased from Acros Chemical Co. and used as received. Coloress plate crystals suitable for X-ray crystallography were obtained by dissolving the title compound in THF, followed by allowing the solution to evaporate slowly under air.

S3. Refinement

The pyrimidyl hydrogen atoms were placed into idealized positions and constrained by the riding atom approximation with C—H = 0.93 Å, and U_iso(H) = 1.2 U_eq(C). The amine hydrogen atoms were located from difference Fourier maps..

Computing details

Data collection: XSCANS (Siemens, 1995); cell refinement: XSCANS (Siemens, 1995); data reduction: XSCANS (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. Crystal structure of the title compound with labeling and displacement ellipsoids drawn at the 30% probability level.Symmetry codes: (i) -x, y, z.

5-Iodopyrimidin-2-amine

Crystal data

C4H4IN3	F(000) = 816
Mr = 221.00	Dx = 2.415 Mg m^−3
Orthorhombic, Cmca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2bc 2	Cell parameters from 31 reflections
a = 7.9088 (7) Å	θ = 4.9–12.6°
b = 8.3617 (10) Å	µ = 5.16 mm^−1
c = 18.3821 (16) Å	T = 295 K
V = 1215.6 (2) Å^3	Plate, colorless
Z = 8	0.6 × 0.4 × 0.2 mm

Data collection

Bruker P4 diffractometer	535 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.032
Graphite monochromator	θmax = 25.0°, θmin = 2.2°
ω scans	h = −1→9
Absorption correction: multi-scan (XSCANS; Siemens, 1995)	k = −1→9
Tmin = 0.332, Tmax = 1.000	l = −21→1
800 measured reflections	3 standard reflections every 97 reflections
573 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.032	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.089	w = 1/[σ^2(Fo^2) + (0.055P)^2 + 3.1925P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max = 0.001
573 reflections	Δρmax = 0.93 e Å^−3
48 parameters	Δρmin = −0.83 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0148 (9)

Special details

Experimental. 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.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 (Ų)

	x	y	z	Uiso*/Ueq
I	0.0000	0.25315 (4)	0.72128 (2)	0.0462 (4)
N1	−0.1515 (4)	0.6239 (4)	0.57261 (16)	0.0378 (8)
N2	0.0000	0.8038 (8)	0.5044 (4)	0.0456 (13)
C1	0.0000	0.4412 (6)	0.6466 (3)	0.0345 (11)
C2	−0.1488 (5)	0.5037 (4)	0.6200 (2)	0.0367 (9)
H2C	−0.2507	0.4604	0.6358	0.044*
C3	0.0000	0.6791 (7)	0.5508 (3)	0.0343 (11)
H2N	−0.085 (7)	0.831 (7)	0.485 (3)	0.061 (15)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I	0.0388 (4)	0.0504 (5)	0.0495 (5)	0.000	0.000	0.01869 (14)
N1	0.0321 (17)	0.0427 (17)	0.0385 (16)	0.0031 (14)	0.0005 (12)	0.0041 (13)
N2	0.039 (3)	0.053 (3)	0.045 (3)	0.000	0.000	0.017 (3)
C1	0.038 (3)	0.033 (2)	0.032 (2)	0.000	0.000	0.002 (2)
C2	0.0329 (19)	0.0406 (19)	0.036 (2)	−0.0011 (16)	0.0016 (15)	0.0034 (14)
C3	0.041 (3)	0.035 (3)	0.027 (2)	0.000	0.000	0.000 (2)

Geometric parameters (Å, º)

I—C1	2.088 (5)	N2—H2N	0.79 (5)
N1—C2	1.331 (4)	C1—C2	1.377 (4)
N1—C3	1.346 (4)	C2—H2C	0.9300
N2—C3	1.346 (10)
C2—N1—C3	116.1 (3)	N1—C2—H2C	118.9
C3—N2—H2N	120 (4)	C1—C2—H2C	118.9
C2^i—C1—C2	117.4 (5)	N1^i—C3—N1	125.9 (5)
C2—C1—I	121.3 (2)	N1^i—C3—N2	117.0 (2)
N1—C2—C1	122.2 (4)

Symmetry code: (i) −x, y, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2N···N1^ii	0.79 (5)	2.37 (5)	3.157 (4)	173 (6)

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