Crystal structure and Hirshfeld surface analysis of the new cyclo-diphosphazane [EtNP(S)NMe2]2.

The cyclic compound 2,4-bis(dimethylamino)-1,3-diethylcyclodiphosphazane-2,4-dithione [systematic name: 2,4-bis(dimethylamino)-1,3-diethyl-1,3,2λ5,4λ5-diazadiphosphetidine-2,4-dithione], C8H22N4P2S2 or [EtNP(S)NMe2]2, is member of a class of mol-ecules that may be used, by virtue of their complexation properties, for the extraction of metals. This compound was characterized in solution by (1H and 31P) NMR, and in the solid state by energy-dispersive X-ray spectroscopy (EDX) and by X-ray crystallography. In the crystal, the mol-ecule sits on an inversion centre such that the P and N atoms form a centrosymmetric cyclic P2N2 arrangement. The crystal packing is dominated by van der Waals inter-actions. The prevalence of these inter-actions is illustrated by an analysis of the three-dimensional Hirshfeld surface (HS) and by two-dimensional fingerprint plots (FP). The relative contribution of different inter-actions to the HS indicates that the H⋯H contacts account for 74.3% of the total HS area.