l-2-Nitrimino-1,3-diazepane-4-carboxylic acid monohydrate

Harutyun A Karapetyan

doi:10.1107/S1600536808015146

. 2008 Jun 7;64(Pt 7):o1222. doi: 10.1107/S1600536808015146

l-2-Nitrimino-1,3-diazepane-4-carboxylic acid monohydrate

Harutyun A Karapetyan ^a,^*

PMCID: PMC2961828 PMID: 21202859

Abstract

The title compound, C₆H₁₀N₄O₄·H₂O, crystallizes with two independent formula units in the asymmetric unit, their geometric parameters being quite similar. The conformations of the 1,3-diazepane rings are also similar and close to a twist-boat. All ten O- and N-bound H atoms are involved in hydrogen bonds, two of which are intra- and eight intermolecular linking crystallographically independent molecules, into a three-dimensional hydrogen-bonded network.

Related literature

For the crystal structures of some analogues of the title compound, see: Apreyan et al. (2008a ▶, 2008b ▶); Karapetyan et al. (2007 ▶); Petrosyan et al. (2005 ▶); Karapetyan (2008 ▶). For related literature, see: Paul et al. (1961 ▶); Apreyan & Petrosyan (2008 ▶).

Experimental

Crystal data

C₆H₁₀N₄O₄·H₂O
M _r = 220.20
Orthorhombic,
a = 9.0115 (18) Å
b = 14.729 (3) Å
c = 15.257 (3) Å
V = 2025.0 (7) Å³
Z = 8
Mo Kα radiation
μ = 0.13 mm⁻¹
T = 293 (2) K
0.22 × 0.17 × 0.12 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: none
6714 measured reflections
2512 independent reflections
1583 reflections with I > 2σ(I)
R _int = 0.040
3 standard reflections every 400 reflections intensity decay: none

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.132
S = 1.02
2512 reflections
286 parameters
6 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.44 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Data collection: DATCOL in CAD-4 Manual (Enraf–Nonius, 1988 ▶); cell refinement: LS in CAD-4 Manual (Enraf–Nonius, 1988 ▶); data reduction: HELENA (Spek, 1997 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808015146/bg2187sup1.cif

e-64-o1222-sup1.cif^{(20.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808015146/bg2187Isup2.hkl

e-64-o1222-Isup2.hkl^{(123.4KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N3ⁱ	0.82	1.90	2.716 (4)	173
N1—H3⋯O3	0.86	2.02	2.586 (4)	123
N2—H10⋯O2ⁱⁱ	0.86	2.05	2.889 (4)	163
O5—H11⋯O9ⁱⁱⁱ	0.82	1.69	2.510 (5)	174
N5—H13⋯O7	0.86	2.04	2.584 (5)	121
N6—H20⋯O6^iv	0.86	2.16	2.937 (5)	150
O9—H21⋯N7	0.83 (4)	2.11 (3)	2.902 (6)	160 (7)
O9—H22⋯O10	0.84 (4)	1.86 (3)	2.662 (7)	159 (7)
O10—H23⋯O7^v	0.86 (4)	2.04 (4)	2.869 (6)	163 (6)
O10—H24⋯O3	0.86 (4)	2.41 (8)	2.856 (6)	113 (5)

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

Acknowledgments

The author thanks Dr R. A. Apreyan and Dr A. M. Petrosyan for providing the crystals and Dr R. A. Tamazyan for valuable discussion of the results.

supplementary crystallographic information

Comment

The L-nitroarginine and its crystaline salts have been investigated as a promising line of non-linear optical materials [Apreyan et al.(2008a) and Apreyan et al.(2008b)]. The cyclic form of L-nitroarginine was reported for the first time in Paul et al., 1961, where it was suggested to be 2-nitro-4-carboxy-1,3-diazacycloheptane. Recently, on the basis of the crystal structure of the cyclic form of L-nitroarginine [Karapetyan, 2008] it was shown to be L-2-nitrimino-1,3-diazepane-4-carboxylic acid (L-NIDCA).

We present herein a structural study of the L-NIDCA monohydrate, C₆H₁₀N₄O₄ × H₂O (I), which crystallizes with two independent formulas in the asymmetric unit, shown in Fig. 1. The metric parameters of independent L-NIDCA molecules are in agreement with commonly accepted values and their conformations are the same, being close to that of a 7-membered ring twist-boat . All ten active H atoms in the crystal are involved in hydrogen bonding (Table 1), two of them being intra- and eight inter-molecular, linking crystallographically independent units and by way of which a tree-dimensional H bonded network results (Fig. 2).

Experimental

By the reaction of L-nitroarginine with KOH the potassium salt was obtained. By the interaction of this potassium salt with HBF4 and further separation of the poorly soluble KBF4 salt, single crystals of (I) were obtained by slow evaporation below room temperature. Details of the obtainment of L-NIDCA and L-NIDCA^.H₂O, as well as vibrational spectra, thermal properties and SHG will be reported soon separately [Apreyan and Petrosyan, 2008].