Crystal structure of N,N′-bis[3-(methylsulfanyl)propyl]-1,8:4,5-naphthalenetetracarboxylic diimide

The title compound, C22H22N2O4S2, was synthesized by the reaction of 1,4,5,8-naphthalenetetracarboxylic dianhydride with 3-(methylsulfanyl) propylamine. The whole molecule is generated by an inversion operation of the asymmetric unit. This molecule has an anti form with the terminal methylthiopropyl groups above and below the aromatic diimide plane, where four intramolecular C-H center dot center dot center dot O and C-H center dot center dot center dot S hydrogen bonds are present and the O center dot center dot center dot H center dot center dot center dot S angle is 100.8 degrees. DFT calculations revealed slight differences between the solid state and gas phase structures. In the crystal, C-H center dot center dot center dot O and C-H center dot center dot center dot S hydrogen bonds link the molecules into chains along the [2 (2) over bar0] direction. adjacent chains are interconnected by pi-pi interactions, forming a two-dimensional network parallel to the (001) plane. Each two-dimensional layer is further packed in an ABAB sequence along the c-axis direction. Hirshfeld surface analysis shows that van der Waals interactions make important contributions to the intermolecular contacts. The most important contacts found in the Hirshfeld surface analysis are H center dot center dot center dot H (44.2%), H center dot center dot center dot O/O center dot center dot center dot H (18.2%), H center dot center dot center dot C/C center dot center dot center dot H (14.4%), and H center dot center dot center dot S/S center dot center dot center dot H (10.2%).