An X-Ray Crystallographic Study of Five Compounds from a Series of 1,x-<Emphasis Type="Italic">bis</Emphasis>-(4-Oxo-3,4-dihydro-1,2,3-benzotriazin-3-yl)alkanes

Abstract  

The crystal structures of a series of bis-(4-oxo-3,4-dihydro-1,2,3-benzotriazin-3-yl)alkanes, compounds 5 to 9, have been determined by single crystal X-ray diffraction analysis. The structural parameters of the triazinone rings in the five compounds do not display systematic differences with respect to those reported for a few analogous compounds. The benzotriazinone rings in 5 and 9 are almost perpendicular to the alkylic chain. The molecules in the crystal packing are linked by means of a weak C–H···X H-bond (X = N/O). Compound 6 has two independent molecules in the asymmetric unit; one of the molecules displays disorder within the benzotriazinone moiety linked in position 1 to the propane alkylic group. The disordered molecule displays two conformations of the benzotriazinone linked in position 1 to the propane bridge. Compound 8 also displays disorder within the benzotriazinone moiety linked in position 1 to the pentane alkylic spacer group. The molecules of compound 7, in the crystal packing, also form intra and inter-molecular C–H···X (X = N/O) hydrogen bonds. None of these compounds show any tendency to adopt a folded conformation with intramolecular π–π stacking between benzotriazinone units. Crystal data: 5 C₁₆H₁₂N₆O_2, monoclinic, space group P2 ₁ /c, a = 4.8370(2)?, b = 14.7845(7)?, c = 10.0837(4)?, β = 95.430(2)°, V = 717.88(6)?³, for Ζ = 2; 6 C₁₇H₁₄N₆O_2, triclinic, space group P-1, a = 7.4237(4)?, b = 14.4738(9)?, c = 15.0359(10)?, α = 91.871(3)°, β = 92.147(3)°, γ = 101.233(3)°, V = 1582.2(2)?³, for Ζ = 4; 7 C₁₈H₁₆N₆O_2, monoclinic, space group C2/c, a = 33.8886(10)?, b = 6.4593(2)?, c = 16.0608(6)?, β = 102.298(1)°, V = 3435.0(2)?³, for Ζ = 8; 8 C₁₉H₁₈N₆O_2, triclinic, space group P-1, a = 7.2592(2)?, b = 7.6795(2)?, c = 16.1003(5)?, α = 85.292(1)°, β = 81.367(1)°, γ = 88.377(1)°, V = 884.26(4)?³, for Ζ = 2; 9 C₂₀H₂₀N₆O_2, monoclinic, space group P2 ₁ /c, a = 7.2668(2)?, b = 4.5612(1)?, c = 28.1993(12)?, β = 97.313(2)°, V = 927.07(5)?³, for Ζ = 2.