Structural study of Nitrovinylindoles: (I) 2-methyl-3-(2'-methyl-2'-nitrovinyl)indole and (II) 3-(2'-nitrovinyl)indole

Article abstract of DOI:10.1007/BF01194317

Compound (I) is 2-methyl-3-(2'-methyl-2'-nitrovinyl)indole, C12H12N2O2, M_r =216,24, monoclinic, P2₁/n, a = 16.710(1), b = 7.627(1), c = 17.646(1) Angstroem, β = 104.8(1) deg, V = 2174.7(1) Angstroem³, Z = 8, D_x = 1.321 g cm^-3, Mo Kα, λ = 0.71073 Angstroem, μ = 0.858 ca^-1, F(000) = 912, room temperature, R = 0.061 for 1956 observed reflections.Compound (II) is 3-(2'-nitrovinyl)indole, C10H8N2O2, M_r = 188.18, monoclinic, P2₁/n, a = 10.178(1), b = 10.608(1), c = 8.411(1) Angstroem, β = 105.5(2) deg, V = 875.0(1) Angstroem³, Z = 4, D_x = 1.4284 g cm^-3, Cu Kα, λ = 1.5418 Angstroem, μ = 8.068 cm^-1, F(000) = 392, room temperature, R = 0.040 for 1330 observed reflections.Compounds (I) and (II) have a similar geometry, the only significant difference lying in the rotation of the nitrovinyl chain.This feature could be responsible for the difference in biological activity.In both compounds, the molecules are associated, forming chargetransfer complexes.