Structural analyses of two N-[(3'-aryl) prop-2'-ynyl]-N, N'-1, 2-phenylene di-p- tosylamides: Supramolecular structure formed by N-H...O, C-H...O, C-H...pi;(arene) interactions.

Department of Physics, Jadavpur University
○Soumen Ghosh Alok Kumar Mukherjee

Quinoxiline systems have been an integral part in many naturally occurring substances, and exhibit important pharmacological activities. In this context, N-[(3'-aryl) prop-2'-ynyl]-N, N'-1,2-phenylene di-p-tosylamides, C27H24N2S3O4 (I) and C29H25N2S2O4Cl (II) have been synthesized, and X-ray crystallographic analyses were undertaken. Both compounds crystallize in a triclinic system, space group P-1 with a =9.0592(6) Å, b = 10.3757(7) Å, c = 14.2600(9) Å, α = 74.623(1)°, β = 82.903(1)°, γ = 78.481(1)° (I) and a = 8.8039(8) Å, b = 11.8783(11) Å, c = 13.1957(12) Å, α = 87.633(1)°, β = 77.257(2)°, γ = 81.915(2)° (II). Intensity data were collected on a Bruker SMART-CCD diffractometer using graphite monochromated MoKα radiation (λ = 0.7107 Å). The crystal structures have been solved by direct methods and refined by full matrix least-squares technique on F2 to R = 0.0423 for (I) and R = 0.0399 for (II) using SHELX 97. Both compounds consist of a planar phenylenediamine part (C8-C13, N1, N2) with a substituted prop-2-ynyl group [C21-C27, S3 in (I) and C21-C29, Cl1 in (II)] at N1 and two p-tosyl moieties (C1-C7, S1, O1, O2 and C14-C20, S2, O3, O4) at N1 and N2 positions, respectively. The molecular packings stabilized by C-H...O, N-H...O and C-H...pi;(arene) interactions, leading to a three- and a two dimensional architecture in (I) and (II), respectively.