Two carbamate derivatives with Z′=2 and 3: An interplay of strong and weak hydrogen bonds

Abstract

Two carbamate derivatives, tert-butyl 3-methyl-1-(3-m-tolylselenoureido)butan-2-yl carbamate (1) and tert-butyl 5-benzyl-2-(3-chlorophenylamino)-4,5-dihydro-1H-imidazole-1-carboxylate (2) have been synthesized and structurally characterized using single crystal X-ray diffraction. The asymmetric unit of 1 comprised of two molecules (Z′ = 2), A and B, and that of 2 had three molecules (Z′ = 3), A, B and C. The crystallographically independent molecules in the asymmetric units of 1 and 2 exhibit an essentially similar conformation but differ in terms of molecular environments. The nature of interactions experienced by different molecules in the asymmetric unit of 1 and 2 has been analyzed through Hirshfeld surfaces and 2D fingerprint plots. The crystal packing exhibits an interplay of NH⋯O, NH⋯Se, CH⋯O, CH⋯Cl and CH⋯π hydrogen bonds, which assemble molecules into a three-dimensional architecture in 1 and 2. The hydrogen-bond based interactions in 1 and 2 have been complemented by molecular electrostatic potential (MEP) surface calculations. In summary, the work highlights how an assembly of molecules connected through hydrogen bonds and displaying pseudo symmetry at a local level can form motifs for structures crystallizing with multiple molecules in the asymmetric unit.