Synthesis, Crystal Structures, Density Functional Theory (DFT) Calculations and Molecular Orbital Calculations of Three New Derivatives of 1-(phenylsulfonyl)indole

Abstract

Three new derivatives of 1-(phenylsulfonyl)indole : 3-nitro-1-(phenylsulfonyl)-1H-indol-2-amine (I): C14H11N3O4S; N-(tert-butyl)-3-nitro-1-(phenylsulfonyl)-1H-indol-2-amine (II): C18H19N3O4S and tert-butyl 4-(phenylsulfonyl)-(1; Pelkey, Gribble, Tetrahedron Lett 38:5603–5606, 1997; 3)triazolo[4,5-b]indole-1(4H)-carboxylate (III): C19H18N4O4S, have been synthesized and their structures determined by single crystal X-ray crystallography. (I), C14H11N3O4S, is triclinic with space group P-1 and cell constants:a = 7.7394(8) A, b = 12.5826(11) A, c = 14.7280(13) A, α = 77.259(8)°, β = 75.885(8)°, γ = 79.342(8)°, V = 1343.6(2) A3, Z = 4. (II), C18H19N3O4S, is monoclinic with space group P21/c and cell constants:a = 16.0499(5) A, b = 12.0196(4) A, c = 9.7866(4) A, β = 104.879(4)°, V = 1824.67(12) A3, Z = 4. (III), C19H18N4O4S, is triclinic with space group P-1 and cell constants: a = 9.0391(8) A, b = 10.3429(12) A, c = 10.8145(11) A, α = 75.870(9)°, β = 71.489(9)°, γ = 88.111(8)°, V = 928.64(17) A3, Z = 2. All three compounds have the same indole nitrogen phenylsulfonyl substituent. In the crystals, the dihedral angle between the mean planes of the pyrrolyl groups of the indole ring and phenylsulfonyl groups are 86.0(8)o (IA) or 83.5(4)o (IB), and 85.0(6)o (III), forming an L-shaped molecule, while in (II) it is 52.9(5)o, forming a V-shaped molecule due in part to the puckering of the pyrrolyl ring from the nonplanar indole group. Additionally, the DFT frontier molecular orbitals of each compound are displayed and correlation between the calculated molecular orbital energies (eV) for the surfaces of the frontier molecular orbitals to the electronic excitation transitions from the absorption spectra of each compound have been proposed. Synthesis, Crystal Structures, Density Functional Theory (DFT) Calculations and Molecular Orbital Calculations of three new derivatives of 1-(phenylsulfonyl)indole: 3-nitro-1-(phenylsulfonyl)-1H-indol-2-amine (I): C14H11N¬3O4S; N-(tert-butyl)-3-nitro-1-(phenylsulfonyl)-1H-indol-2-amine (II): C18H19N3O4S and tert-butyl 4-(phenylsulfonyl)-[1,2,3]triazolo[4,5-b]indole-1(4H)-carboxylate (III): C19H18N4O4S.