| Abstrakt: |
A series of five S-benzyl esters of pyrrolidine dithiocarbamate, differing only in the substituent in the 4-position of the benzyl group, i.e. (CH2CH2)2NC(＝S)SCH2C6H4-4-Y for Y = Cl, Br, I, Me and NO2 (1–5), have been investigated by crystallographic and computational chemistry techniques, including analyses of the calculated Hirshfeld surfaces and the calculation of interaction energies. Remarkable differences in molecular conformations, e.g. almost 90° differences in the C–S(thioether)–C(methylene)–C torsion angles, are related to packing effects as revealed through unrestricted geometry-optimisation calculations. The influence of the remote substituent, Y, upon the molecular packing is crucial with four different packing patterns elucidated. In the chlorine derivative, 1, Cl⋯Cl contacts feature between layers having C–H⋯π interactions. In each of the isomorphous bromine (2) and iodine (3) derivatives, X⋯S halogen-bonding is detected within linear supramolecular chains which assemble into layers through phenyl-C–H⋯S(thione), methylene-C–H⋯π(phenyl) and off-set phenyl-π⋯π(phenyl) stacking. Layers are also evident in the methyl species, 4, with directional pyrrolidine-C–H⋯π(phenyl) and π(phenyl)⋯π(phenyl) interactions apparent between molecules. In the three-dimensional architecture of nitro derivative 5, methylene-C–H⋯π(phenyl) and long phenyl-C–H⋯O(nitro) interactions are discerned. The X⋯S halogen-bonding is more significant for 3cf.2 based on geometric criteria and calculated interaction energies. [ABSTRACT FROM AUTHOR] |
