5-[1-(4-Methoxyphenyl)-2-nitrobutyl]-4-phenyl-1,2,3-selenadiazole

In the title compound, C19H19N3O3Se, the selenadiazole ring is essentially planar (r.m.s. deviation = 0.001 Å). The heterocyclic ring makes dihedral angles of 50.2 (2) and 76.3 (9)°, respectively, with the methoxyphenyl and phenyl rings.


Related literature
Glutathione peroxidases(GPx) are the antioxidant selenoenzymes protecting various organisms from oxidative stress by catalyzing the reduction of hydroperoxides at the expense of glutathione(GSH) (Stadtman, 1991). Owing to the above said important properties of selenium containing compounds, the crystal structure of the title compound is carried out.
The ORTEP plot of the molecule is shown in Fig.1

Refinement
H atoms were positioned geometrically (C-H=0.93-0.98 Å) and allowed to ride on their parent atoms,with U iso (H) = 1.5U eq (C) for methyl H 1.2U eq (C) for other H atoms.

Figure 1
The molecular structure of the title compound, showing the atomic numbering and displacement ellipsoids drawn at 30% probability level. Hydrogen atoms have been omitted for clarity.  The crystal packing of the molecules viewed down c axis.

Special details
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 F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 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 (Å 2 )
x y z U iso */U eq C1 0.7080 (