3-(2-Ethoxyphenyl)-1-(3-nitrophenyl)triaz-1-ene

The title compound, C14H14N4O3, exhibits a trans geometry about the N=N double bond in the triazene unit. The molecule is approximately planar (r.m.s. deviation = 0.044 Å for all non-H atoms). An intramolecular N—H⋯O hydrogen bond occurs. In the crystal, C—H⋯N hydrogen bonds lead to the formation of dimers which are, in turn, connected to each other by C—H⋯O hydrogen bonds, forming infinite chains of R 2 2(8) graph-set motif.

The title compound, C 14 H 14 N 4 O 3 , exhibits a trans geometry about the N N double bond in the triazene unit. The molecule is approximately planar (r.m.s. deviation = 0.044 Å for all non-H atoms). An intramolecular N-HÁ Á ÁO hydrogen bond occurs. In the crystal, C-HÁ Á ÁN hydrogen bonds lead to the formation of dimers which are, in turn, connected to each other by C-HÁ Á ÁO hydrogen bonds, forming infinite chains of R 2 2 (8) graph-set motif.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: QM2042).
The title compound, C 14 H 14 N 4 O 3 , is a related triazene compound. It exhibits a trans stereo chemistry of the N═N double bond, and the C9-N3-N2-N1 and C1-N1-N2-N3 torsion angles are -179.23 (9) and 177.91 (10)°, respectively which indicates the molecule is planar. The N1-N2 and N2-N3 bond distances are 1.3295 (13) and 1.2550 (14) Å, respectively, which indicates the presence of distinct single and double bonds between the nitrogen atoms. These values are in good agreement with the reported data for N-N and N═N bond distances (Hematyar, et al., 2008;Payehghadr, et al. 2007). For example, in 1,3-bis(2-cyanophenyl)triazene, the N-N and N═N bond distances are 1.335 (5) and 1.289 (5) Å (Melardi, et al., 2008). Individual molecules are mostly planar with an r.m.s. deviation from planarity of 0.044 Å for all non-hydrogen atoms. Every molecule in the molecular structure ( Fig. 1) is connected to other unit by two distinct C-H···N hydrogen bonds to form dimers. The resultant dimers are then connected to each other by C-H···O hydrogen bonds to form infinite chains with R 2 2 (8) graph-set motifs (Grell et al., 2002)) ( Fig. 2). Unit cell diagram of the title compound is illustrated in Fig. 3.

Experimental
The compound was prepared by the following method: A 100 ml flask was charged with 10 g of ice and 15 ml of water and then cooled to 273 k in an ice-bath. To this was added 2 mmol (0.344 g) of 3-nitroaniline and 2 mmol of hydrochloric acid (36.5%) and 2 ml of water. To thissolution was then added a solution containing NaNO 2 (2 mmol, 0.16 g) in 2 ml of water during a 15 min period. After mixing for 15 min, the obtained solution was added to a solution of 2 mmol (0.261 ml) of o-phenetidin and 2 ml of methanol and 2 ml of water.
After that a solution containing 36 mmol (2.95 g) of sodium acetate in 10 ml of water was added. After mixing for 24 h the orange product was filtered off and dissolved in DMSO. Recrystallization from DMSO afforded the product as an orange crystalline material. 1 Fig. 1. Molecular structure of the title compound. Thermal ellipsoids are drawn at the 50% probability level.